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FreeOTFE / FreeOTFE4PDA

1. sl Fiy Computer ead Sha Program Files Mb 314 Floppy 4 Groo SD Card Se Local Disk C std 3 Temp CD vie nT Wind a Hard i Windows Se FREEOTFE E a F lt i Se Loc S w Shared Documents lt FRE H C root s Documents W stduser s Documents Devi EA My Network Places Up Menu wg Recycle Bin 3 3c PC version PDA version Explorer showing mounted volume You can have more than one volume mounted at the same time 4 5 Dismounting volumes Once you have finished using your secured drive it should be dismounted This will remove the virtual drive and wipe any sensitive information FreeOTFE has stored in the computers memory Select which volumes shown in the main FreeOTFE window you wish to dismount and click the File Dismount menuitem or use the context menu shown by rightclicking on one of the volumes shown tap and hold on the PDA version j FreeOTFE4PDA 11 03 X FreeOTFE FreeOTFE storage File View Tools Help SD Card TestVolumeOne vol Disa ee reeOTFE storage 2 2 722 SD Cardi Te Explore Drive Volume Dismount amp E C TestVolumeOne vol EE Dismount Ctrl D Properties Ei Dismount all Format Overwrite free space Properties Alt Enter F Free Space 24 7 MB Total Size 24 7 MB Ey PC version PDA version Main window context menu To quickly dismount all mounted volumes use the Dismount all menuitem 4 6 Changing
2. 4 Getting Started Guide Pretty much everything in FreeOTFE works as it seems and should be fairly self explanatory If there s anything you re not too sure of most times an educated guess will give you the right answer 4 1 Installation Portable mode Before FreeOTFE can be used it must first either be installed or uncompressed from the releaes archive Please see the section on Installation and Upgrading for instructions on how to do this 4 2 Using FreeOTFE Once FreeOTFE is installed or started in portable mode securing your data is simple 1 Create a volume to store your encrypted data on or several if you choose 2 Mount the volume created 3 Once mounted your volume will appear as a new drive a virtual drive on your system Anything and everything stored on this drive documents pictures videos software whatever you like will be automatically encrypted and stored within the volume you created at the point that it s written to the drive The encryption process is totally transparent to the user and is carried out on the fly as data is written to the drive Similarly decryption is carried out transparently when data is read from it You can drag files to and from this drive open and save files from applications to it run applications directly from it in fact everything that you can do with a normal drive you can do with a FreeOTFE virtual drive 4 To secure your data simply dismount
3. IV generation 32 bit sector ID 9 8 3 Example 1 Volume Without Encryption This is the simplest form of Linux volume file and the recommended starting point for checking that FreeOTFE is operating correctly 54 Creating the volume file under Linux dd if dev zero of vol_none bs 1k count 1024 losetup dev loop0 vol_none mkdosfs dev loop0 mkdir test_mountpoint mount dev loop0 test_mountpoint echo This is a text test file gt test_mountpoint SHORT_TEXT txt umount dev loop0 losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume file 3 Key tab Leave key blank Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the Null hash Leave iteration count at 0 4 Encryption tab Select the Null cypher Select the Null IV IV generation method The Hash with A s if hash output is too short makes no difference 5 File options tab Leave offset at 0 Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button 9 8 4 Example 2 Volume Encrypted Using XOR This is the second simplest form of Linux volume file and is the simplest case to confirm that passwords are being accepted and used correctly Creating the volume file under Linux dd if dev zero of vol_xor bs 1k count 1024 losetup e XOR
4. Q Can I use FreeOTFE with my USB flash drive A Yes FreeOTFE has been designed to be portable see the section on Portable Mode for details on which files to copy onto your USB drive Alternativly insert your USB drive and select the Tools Copy FreeOTFE to USB drive menuitem to automatically copy FreeOTFE to your USB drive You can then use FreeOTFE on any PC even if it doesn t have FreeOTFE installed Q Why doesn t FreeOTFE run automatically when I insert my USB drive A If you used the Tools Copy FreeOTFE to USB drive function and selected the Setup autorun inf to launch FreeOTFE when drive inserted option FreeOTFE will normally run automatically whenever the drive is inserted or prompt the user if they want to run it However this does depend on your PC s configuration If FreeOTFE doesn t launch automatically and you don t get prompted to launch FreeOTFE after inserting the drive you probably have autorun turned off for removable disks It is generally recommended that autorun SECURITY functionality be disabled as this can have security implications should an untrusted USB drive be plugged in the program specified in an autorun inf file on the device may be launched without offering the user the chance to prevent it To reset enable autorun functionality 1 Click the windows Start button 2 Select Run 3 Type in gpedit msc and click OK 4 Reset the setting for the
5. 2 Add the path to the modified Delphi files included in SDeanComponents to fix various bugs relating to Delphi 2006 s Windows Vista support to the top of Delphi s standard library paths This step probably won t be needed with later versions of Delphi and shouldn t be carried out with older versions of Delphi which will have different source 3 Open the FreeOTFE project FreeOTFE dpr 4 If you have the dxgettext software installed see above ensure that the compiler directive _DXGETTEXT is set Otherwise make sure that this compiler directive is not set 5 Build the application 6 You should now find a file called FreeOTFE exe in the directory above the src directory You have now successfully built the GUI frontend If required the compiler definition FREEOTFE_TIME_CDB_DUMP may be set in which case the time taken to dump a CDB Tools Critical data block Dump to human readable file will be shown after the dump completes 150 13 9 1 2 Building the Kernel Drivers The kernel mode drivers implement the actual hash encryption decryption and main FreeOTFE drivers To build these drivers the following software is required Microsoft Visual Studio 2008 older versions may well be used changing vevarsall to vevars32 and similar changes O If using an older version of MS Visual Studio the MS Windows SDK February 2003 version is also needed The MS Windows WDK WDK for Server 2008 v6001 18
6. 512 512 LibTomCrypt 2 Download The latest release of FreeOTFE together with its source code may be downloaded from the official site at http www FreeOTFE org download html PGP MD5 and SHA 1 signatures for this software may also be found on the above WWW site If you would like to build your own copy of FreeOTFE you will also need the SDeanComponents package required for building the GUI which may be downloaded from http www SDean12 org SDeanComponents htm 3 Installation and Upgrading 3 1 PC Version NOTE Windows Vista x64 64 bit users only should also read the additional information for Windows Vista x64 users section in order to configure their system before use As with the PDA version if you wish to use FreeOTFE in portable mode you do not have to carry out the installation described below simply copy the binary exe and sys files to wherever you would like them stored and doubleclick on FreeOTFE exe i e the file with the combination lock icon From there you can then start using FreeOTFE in Portable Mode Alternatively if you would like to carry out a full installation which will allow non administrator users to mount and use FreeOTFE volumes follow either of the automatic or manuall installation instructions detailed below 3 1 1 Automatic installation 1 Download the installer version of FreeOTFE and run the executable 2 After prompting you for some simple detail
7. Locating cmd exe under C Windows System32 in Windows Explorer rightclicking on this executable and selecting Run as Administrator from the context menu 2 Click continue or enter the administrator s password as appropriate and click OK when asked for permission to continue 3 In the command prompt window which appears type bcdedit exe set nointegritychecks ON 4 Reboot the PC 3 1 3 3 Method 2 DDISABLE_INTEGRITY_CHECKS Instructions 1 Open an elevated command prompt by either Clicking the Start button on the Windows taskbar type CMD in the search box and then press lt CTRL SHIFT ENTER3 gt to run CMD with administrator privileges or Locating cmd exe under C Windows System32 in Windows Explorer rightclicking on this executable and selecting Run as Administrator from the context menu 2 Click continue or enter the administrator s password as appropriate and click OK when asked for permission to continue 3 In the command prompt window which appears type bcededit set loadoptions DDISABLE_INTEGRITY_CHECKS Note That s DDISABLE with two Ds for Driver Disable 4 Reboot the PC This method will work however installing Windows Vista x64 Service Pack 1 SP1 or any of the following Windows Vista hotfixes will cause this method to cease working KB932596 Update to improve Kernel Patch Protection 1KB938194 An update is available that improves the compatibilit
8. Uninstalling drivers except Windows Vista runas user myAdminAccount FreeOTFE exe drivercontrol uninstall drivername FreeOTFE runas user myAdminAccount FreeOTFE exe drivercontrol uninstall drivername FreeOTFEHashSHA runas user myAdminAccount FreeOTFE exe drivercontrol uninstall drivername FreeOTFECypherAES 8 2 PDA Version 8 2 1 Synopsis FreeOTFE4PDA exe mount volume lt volume gt freeotfe linux keyfile lt keyfile gt password lt password gt mountpoint lt mountpoint gt freeotfe readonly offset lt offset gt nocdbatoffset saltlength lt saltlength gt keyiterations lt keyiterations gt silent noexit FreeOTFE4PDA exe dismount lt mountpoint gt all force FreeOTFE4PDA exe create 44 8 2 2 Description FreeOTFE4PDA supports a number of command line options that allow a number of its main functions to be carried out from the command line or via MS Windows shortcuts 8 2 3 Options Note that may be substituted in place of if required Important Any mountpoints or filenames with spaces in them must be enclosed in double quotes create Create new FreeOTFE volume dismount lt mountpoint gt all Dismount indicated volume all mounted volumes force When dismounting force dismount emergency dismount freeotfe The specified volume is a FreeOTFE volume keyfil lt keyfile gt The keyfile to be used
9. Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the MD5 128 512 hash Ensure Hash with A s if hash output is too short is checked Leave iteration count at 0 4 Encryption tab Select the Blowfish CBC 448 64 cypher Select ESSIV as the IV generation method Set Sector zero location to Start of encrypted data Select SHA 256 256 512 as the IV hash Select Blowfish CBC 256 64 as the IV cypher 5 File options tab Leave offset at 0 Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button 9 9 10 Example 8 Volume Encrypted Using AES 256 in XTS Mode aka XTS AES 256 This example demonstrates use of a dm crypt AES 256 volume in XTS mode aka XTS AES 256 and using SHA 512 for hashing Creating the volume file under Linux dd if dev zero of volumes vol_aes_xts vol bs 1K count 100 losetup dev loop0 volumes vol_aes_xts vol echo password1234567890ABC cryptsetup h sha512 c aes xts plain key size 512 create myMapper dev loop0 dmsetup 1s dmsetup table dmsetup status losetup dev loop1 dev mapper myMapper mkdosfs dev loopl mkdir test_mountpoint mount dev loopl test_mountpoint cp test_files SHORT_TEXT txt test_mountpoint cp test_files BINARY_ZEROS dat test_mountpoint cp test_files BINARY_ABC_RPTD dat test_mountpoint c
10. pseudorandom data can potentially be identified as such and become predictable In this case your hidden volume will not appear as high entropy data stuck in the middle of a series of 0x00 bytes but as high entropy data interrupting any pattern formed by the pseudorandom data Because truly random data can be difficult to rapidly generate in large quantities using a computer Pseudorandom data can still be used though by encrypting it before it is written to the host volume file In principle although not as good as a cryptographically secure RNG this should give the data written to the volume file a suitable degree of entropy The easiest way of accomplishing this is which will work with any OTFE system is to mount the host volume as per normal and overwrite all of its free space with a single pass of pseudorandom data The data written to the mounted volume will be encrypted as it is written to the host volume file 10 4 More Advanced Hidden Volumes The technique described above for mounting and overwriting a volume before creating a hidden volume on it still isn t enough though If you were to be forced to hand over the key to the outer host volume an attacker could then apply the same analysis but this time to the mounted plaintext version of your host volume Again any hidden volume may well stick out in any pattern within the pseudorandom data The solution suggested is to encrypt the pseudorandom data before it is us
11. 1 Select Linux Mount 2 Select the volume file 3 Key tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the RIPEMD 160 160 512 hash Ensure Hash with A s if hash output is too short is checked Leave iteration count at 0 4 Encryption tab Select the AES CBC 256 128 cypher Select 32 bit sector ID as the IV generation method Set Sector zero location to Start of encrypted data 5 File options tab Leave offset at 0 Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button 9 9 4 Example 2 Volume Encrypted Using 128 bit AES This example demonstrates use of a dm crypt AES128 volume Creating the volume file under Linux dd if dev zero of volumes vol_aes128 vol bs 1K count 100 losetup dev loop0O volumes vol_aes128 vol echo password1234567890ABC cryptsetup c aes s 128 create myMapper dev loop0 dmsetup ls 63 dmsetup table dmsetup status losetup dev loop1 dev mapper myMapper mkdosfs dev loopl mkdir test_mountpoint mount dev loopl test_mountpoint cp test_files SHORT_TEXT txt test_mountpoint cp test_files BINARY_ZEROS dat test_mountpoint cp test_files BINARY_ABC_RPTD dat test_mountpoint cp test_files BINARY_OO_FF_RPTD dat test_mountpoint umount test_mountpoint losetup d dev loop1 cryptsetup
12. 11 1 1 Windows Vista and Windows 7 Specific 11 1 1 1 User Access Control UAC Windows Vista incorporates alnew security system called User Access Control UAC which is there to help prevent malicious software from doing things which could be harmful to your computer As part of this new security system you will find a number of FreeOTFE s menuitems are marked with a shield icon specifically those which relate to installing or changing FreeOTFE s drivers starting stopping portable mode and formatting Whenever you attempt to use functionality which is marked with one of these icons Windows will display a dialog the consent credential dialog asking for your permission to allow FreeOTFE to continue This is for your protection and is perfectly normal You will be shown this dialog even if you are logged on as an Administrator Although the FreeOTFE binaries are digitally signed using the Microsoft standard Windows refuses to identify FreeOTFE and as such this dialog will state that An unidentified program wants access to your computer Again this is perfectly normal if you would like to check that your copy of FreeOTFE is an unmodified original copy you may do so by checking the hashes signatures available 80 from the FreeOTFE WWW site If you are logged on as a standard i e non Administrator user the prompt you are shown will also ask for an Administrator s password It should be emphasised that it is Wi
13. 9 9 8 Example 6 Volume Encrypted Using 256 bit AES with MD5 Password Hashing This example demonstrates use of a dm crypt Twofish 256 volume with the user s password processed with MDS Creating the volume file under Linux dd if dev zero of volumes vol_aes_md5 vol bs 1K count 100 losetup dev loop0 volumes vol_aes_md5 vol echo password1234567890ABC cryptsetup c aes h md5 create myMapper dev loop0d dmsetup 1s dmsetup table dmsetup status losetup dev loopl dev mapper myMapper mkdosfs dev loop1l mkdir test_mountpoint mount dev loopl test_mountpoint cp test_files SHORT_TEXT txt test_mountpoint cp test_files BINARY_ZEROS dat test_mountpoint cp test_files BINARY_ABC_RPTD dat test_mountpoint cp test_files BINARY_0OO_FF_RPTD dat test_mountpoint umount test_mountpoint 67 losetup d dev loopl cryptsetup remove myMapper losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume file 3 Key tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the MD5 128 512 hash Ensure Hash with A s if hash output is too short is checked Leave iteration count at 0 4 Encryption tab Select the AES CBC 256 128 cypher Select 32 bit sector ID as the IV generation method Set Sector zero location to Start of encrypted d
14. If specified this must be set to the full path and filename of the keyfile keyiterations lt keyiterations gt The number of key iterations linux The specified volume is a Linux volume If a volume type FreeOTFE Linux isn t specified when mounting freeotfe will be assumed mount Mount indicated file partition mountpoint lt mountpoint gt The mountpoint where the volume is to appear nocdbatoffset Indicates that there is no CDB at the offset with the volume This parameter has no effect unless the keyfile parameter is specified noexit Normally when run with command line parameters FreeOTFE4PDA carries out the requested action and exits Specifying this parameter will cause FreeOTFE4PDA to continue running offset lt offset gt The offset within the file in bytes password lt password gt The password to be used It is not recommended that this is used particularly in shortcuts as this would involve storing your password in plaintext such that anyone can read it readonly Mount the volume readonly saltlength lt saltlength gt The length of the salt in bits silent Can be used when mounting a volume to prevent the password entry dialog showing volume lt volume gt The volume filename partition to be used This should be set to the full path and filename of a volume file 45 8 2 4 Exit Codes When run at the com
15. and then mount them using FreeOTFE These examples have been tested using SuSE 9 2 though they should work for all compatible Linux distributions 53 9 8 1 Initial Setup To begin using Cryptoloop under Linux ensure that the various kernel modules are installed modprobe cryptoloop modprobe deflate modprobe zlib_deflate modprobe twofish modprobe serpent modprobe aes_i586 modprobe blowfish modprobe des modprobe sha256 modprobe sha512 modprobe crypto_null modprobe md4 modprobe md5 modprobe arc4 modprobe khazad modprobe anubis Typing Ismod will show you which modules are currently installed The examples shown below may then be followed to create and use various volume files 9 8 2 Defaults If not overridden by the user Cryptoloop defaults to no encryption If the user specifies that they do want encryption i e passes losetup a e parameter Cryptoloop defaults to the following Cypher As specified by the user no encryption takes place if no cypher is specified Cypher keysize 128 bit The hash used to process the user s key is dependant on the cypher s keysize Cypher keysize Hash 128 191 bits SHA 256 User key 192 255 bits SHA 384 processed with 256 bits SHA 512 Hash with A s if hash output is too short option this option should not be selected if the hash used outputs too few bits its output is right padded with 0x00 characters to the required length
16. install the Gladman version of Twofish while installing the libtomcrypt version of AES Installing all of the drivers them is harmless but does mean that you ll be prompted which one to use during mounting a volume if more than one can be used to encrypt decrypt that volume 3 1 2 1 Upgrading from a Previous Version Because of potential changes within the driver API you must ensure that you completely uninstall your existing FreeOTFE installation before installing and using the latest version Please see the section on uninstalling for details on how to do this 3 1 2 1 1 Special Notes if Upgrading from v2 00 Although the FreeOTFE drivers are backwardly compatible v2 00 of the main FreeOTFE driver cannot correctly use LRW or XTS encrypted volumes Such volumes may be mounted with the v2 00 driver but their contents will not be usable 3 1 2 1 2 Special Notes if Upgrading from v00 00 02 With the possible exception of those volumes which were generated using the NULL hash algorithm which was only intended for testing purposes the latest version of FreeOTFE should be backward compatible with existing volume files and you should experience no problems with mounting and using them You will notice that when mounting volumes you are presented with more options than with your previous version of FreeOTFE For the purposes of mounting older volumes these additional controls can be ignored except for the salt length option Newer v
17. most users leave it at its default value unless there is a particular need to do otherwise Salting your password increases security and will slow down dictionary attacks against your volume cept Ee al Key iterations 2048 e Note The value entered must be a multiple of 8 Note You will be required to enter this value every time you mount your volume For this reason it is recommended that most users leave it at it s default value unless you have a particular need to do otherwise PC version PDA version Advanced volume creation options 5 4 1 Key Iterations Before the user s password is used to encrypt decrypt the CDB it is processed using PBKDF2 to increase security This tab allows the number of PBKDF2 iterations to be set by the user higher values increase security but will also increase the amount of time taken to mount the volume This becomes more significant when mounting volumes on a PDA which typically have slower CPUs The default number of key iterations is 2048 5 4 2 Salt Before the user s password is used to encrypt decrypt the CDB it is processed using PBKDF2 to increase security Part of this processing involves the use of a random salt value which reduces the risk of dictionary based attacks This tab allows the length of the salt value in bits to be set by the user 25 It should be noted that every time a volume which has a non default 256 bit salt length is mou
18. switch try removing it and just clicking OK on the password dialog to confirm that your password and other details have been entered correctly If FreeOTFE fails to mount check your command line parameters carefully If your password or volume filename have spaces in them you ll need to surround them with doublequotes Similarly signs may be interpreted in batch files as batch file variables Q Do I have to partition my drive to use FreeOTFE A No FreeOTFE volumes may be stored in files stored on your normal file system Q I want to create a FreeOTFE partition on my unallocated space but can t see it in the partition display where is it A For obvious reasons the FreeOTFE only shows partitions which are reported to it by the OS Disk space which does not form any part of a partition i e is not referenced in any partition table on the disk primary or extended reported as Unallocated by the Windows Disk Management tool cannot be seen by FreeOTFE 109 To make use of such space use the Windows Disk Management tool to create a new partition for it and then use FreeOTFE to turn it into an encrypted partition Please note that FreeOTFE is not responsible for partitioning your hard drive you should be using a partitioning tool for that Q When I m prompted to select a partition some of the partitions on my USB drive are shown in red or not at all why A See Why can t I use encrypt
19. t I use encrypted partitions on a USB drive unless it s the first partition After creating an encrypted partition MS Windows reports that partition I used as being type RAW and prompts me to format it why How do I hide an encrypted partition such that MS Windows doesn t allocate it a drive letter O Why does the partition disk selection display sometimes display less information Taccidentally selected the wrong disk partition when creating a new volume and now can t see my files How can I get my data back O Does FreeOTFE offer whole disk encryption Security Token Smartcard Support PKCS 11 Dol have to use a security token smartcard with FreeOTFE O What is the difference between PKCS 11 Cryptoki and tokens Does FreeOTFE encrypt my entire encrypted volume using my PKCS 11 token O ve inserted my PKCS 11 Cryptoki token but why is the PKCS 11 token management menuitem disabled How do I change the password on a volume keyfile which is secured with a PKCS 11 secret key O 84 O O Can I use more than one security token with FreeOTFE Why don t all of my volumes automatically dismount when I remove my security token Windows Vista specific O oo0o0o0 Why do I get unidentified program wants access to your computer prompts when using FreeOTFE Why does FreeOTFE prompt me to enter my Administrator s password How do I stop the Windows Vista consent credential UAC dialog from
20. 1 As a secure keyfile store 2 To add an additional level of encryption to keyfiles volumes In both cases case the token s password typically called a PIN although not limited to numbers is required in order for the token to be used These two methods can be used independently or combined together 7 1 Initial configuration In order to use tokens FreeOTFE must first be configured to use the appropriate PKCS 11 library Go to View Options Select the PKCS 11 tab Check the Enable PKCS 11 support checkbox The filename of the PKCS 11 library you wish to use see table below Note In most cases you shouldn t need to enter the full path to the DLL just its filename Click Verify to run a quick sanity check to ensure that the library looks viable Set Save above settings to be for example FreeOTFE executable dir 7 Click OK WN eR nN 35 Options General Hotkeys System Tray Autorun PKCS 11 Security Token Smartcard support Enable PKCS 11 support PKCS 11 library Automount dismount C Auto mount specified volume on token insertion C Auto dismount PKCS 11 volumes when associated token is removed Save above settings to FreeOQTFE executable dr v C Associate FreeOTFE with vol files Options dialog PKCS 11 tab The menuitem under the Tools menu should then be enabled as should the options when appropriate on the password entry dial
21. 4 More Advanced Hidden Volumes Coke mee a at ae at aagana e am aT 10 5 a E e oh hue a one ES DiM conen Noe a e cae uc 28 Ge oe ee ee RO 1LIPC Version A we ew At ee Be ae 2 11 1 Windows Vista and Windows 7 Specifi Aproape ee me Tah Go ae 3 BO 11 2 PDA Version en ae a eae ae ee IEA amp BS Rk UA ee De RB OR ee Oe A Ae a eke 82 I21F Me a a ee a a es a a a 12 1 1 General we tee ee OA A Oe E 12 1 2 FreeOIFE Specific PO s ww ee BB 12 1 3 FreeOTFEAPDA Specific PDA ee ee 85 12 1 A ErecOTFE Explorer Specifid A ap em e a ah e TA ses 8 12 2 General A a A aa e yk RL Re e a te 7786 1233F Monde e a af a cm a ce Ot 12 RECOTETE DA Sec POST oe ee at bm woe amp Be oe Mine 12 5 F Pies ee ee ee ae Se all 13 T com SO deaa ob Ge WR one aaee a ue tees B TERSSOTTE Volar cad KVR so o te a me Ga we IDB 13 1 1 Notes i Pa ak we y we e a a a 13 2 Technical Details Critical Data Block Layouts gt 5 o ooo 1B 13 2 11C a Se TI Bee ns Se ee D 13 2 218D5 Focmar i SD the ee se ep Ge aes Ce SHE 132 3 CDE Fomai IDa s s s Acr oA anaa ao om a IBF 13 2 4 CDB Format IDA ee 142 133 Me at be de bo ok ge ce we ae oR we AS 13 3 1 ee Ke at aa ae Sn ut fe at We oe oe 13 4 MountingFreeQTFE Volumes s gt a A we 144 13 4 Additional information Se Se ty Eo a Ge e a ia 13 5 E poses ge in ae R Soa a 6 13 5 Per SexorV Genesio Spied ate WS Ce eg he ES 13 6 Registry Entries oO oe e em te ee Bae a
22. Advanced Topics 5 1 Keyfiles A keyfile is a small file about 512 bytes which can optionally be created for a volume and contains a copy of the information required to mount a FreeOTFE volume Keyfiles are encrypted based a user supplied keyfile password which must be supplied in order to use the keyfile ns More than one keyfile can be created for the same volume Keyfiles are useful as they allow critical information which is required in order to mount a particular volume to be stored separately to the volume which they relate to on a floppy disk or USB drive for example which would be too small to store the entire volume on In this way your volume may be stored on your computer but the information required to access it can be stored in a physically more secure location e g in a locked safe In a business environment keyfiles may be used as a form of password recovery or to reset forgotten passwords When confidential information is held within a FreeOTFE volume a keyfile can be created for that volume and stored in a safe location Should the employee which normally uses the volume be unavailable or cannot remember the volume s password the volume may still be mounted using a keyfile that has was previously created for it together with that keyfile s password even if the volume s password has been subsequently changed Keyfiles may also be used to provide multiple users with access to mount and use the same
23. Fix to correct bug with salt handling which prevented FreeOTFE volumes from being 169 mounted v0 00 01 BETA 1 10th October 2004 O First public release for compatibility testing 17 2 PDA Version v5 21 7th February 2010 O O O Added Russian language translation Added translator credit to About dialog Fix bug in tap n scribble RNG causing error message to be displayed v5 20 3rd January 2010 OO0O0000 Display layout changes made to better support translated interface Added Greek language translation Added Croatian language translation Added language translator credits dialog Added hash cypher details dialogs Changed password reading routines to better support Windows Mobie 6 5 Microsoft changed the manner in which WM65 accepted passwords entered by the user v5 10 13th October 2009 O00 0 Added Czech translation Added Japanese translation Updated German and Spanish translations Fix bug in release procedure causing only Spanish translation to be included Caused by longstanding fault in cabwiz exe Thanks a lot Microsoft v5 00 22nd July 2009 0000000 0 O O Optimised mount performance Added functionality to support language translations Added support for Linux LUKS volumes Added XTS mode to Gladman cyphers AES MARS RC 6 Serpent and Twofish Added RIPEMD 256 and RIPEMD 320 hash algorithms Added option to volume creation wizard to mount new volumes after crea
24. I get unidentified program wants access to your computer prompts when using FreeOTFE This FAQ is only applicable when running under Windows Vista and later it is not relevant for other operating systems A Windows Vista incorporates a new security system called User Access Control UAC which is there to help prevent malicious software from doing things which could be harmful to your computer Whenever you attempt to use any part of FreeOTFE s functionality which Windows considers a malicious program could use to cause harm Windows displays this dialog called the consent credential dialog and asks you if you would give your permission for it to continue You will be shown this dialog even if you are logged on as an Administrator The same type of dialog will appear when you attempt to for example go to Window s Control Panel selecting Date and Time and then attempting to change the computer s time or date Because the FreeOTFE executable does not have a digital signature that Windows recognises this dialog claims that An unidentified program wants access to your computer This is perfectly normal and part of Vista s system to help protect you If you would like to check that your copy of FreeOTFE is an original you may do so by checking the hashes signatures available from the FreeOTFE WWW These prompts form part of Windows Vista s User Access Control UAC system which you can find out more about from
25. I save my settings in the same directory as my FreeOTFE executable Where and in what order does FreeOTFE search for my settings After associating FreeOTFE with vol files from the options dialog I doubleclicked my vol volume file and nothing happened Why do volumes created with the FreeOTFE v2 00 and later have the extension vol What is the difference between the Overwrite free space and Overwrite entire drive options under the Tools menu Does FreeOTFE support encrypting data with multiple cyphers aka cascaded cyphers or superencryption FreeOTFE supports different languages but why isn t mine listed How do I translate FreeOTFE into a different language Can I defragment encrypted volumes Can I use FreeOTFE with my USB flash drive Why doesn t FreeOTFE run automatically when I insert my USB drive Can I use FreeOTFE with MojoPac Can FreeOTFE be used with RAID arrays Does FreeOTFE try to connect to the internet How do I check FreeOTFE s exit code when passing parameters via the command line Why won t FreeOTFE accept my password when supplied via the command line parameter Partition based volumes Do have to partition my drive to use FreeOTFE I want to create a FreeOTFE partition on my unallocated space but can t see it in the partition display where is it O When I m prompted to select a partition some of the partitions on my USB drive are shown in red or not at all why O Why can
26. O Fixed bug found when creating a new volume and storing the volume s CDB separately The CDB file wasn t being created before the CDB was written to it causing an Unable to write critical data block error e v00 56 00 BETA 7th May 2005 restricted release Corrected issues relating to formatting volumes v00 54 00 BETA 7th May 2005 restricted release O Now tested under Windows 2000 as well as Windows XP Removed buffering between data transfers to increase reliability O Updated to fix Format incomplete problems when formatting as FAT FAT32 while running under Windows 2000 Added warning to user if an attempt is made to use a volume file created with a later volume format layout ID Corrected fault with Windows XP Windows 2000 differing QueryDosDevice behaviour that sometimes prevented FreeOTFE listing all cyphers hash algorithms installed Updated to only accept drag n dropped files when the drivers are active Extra checks included to ensure user has at least one hash and cypher driver installed and running O Fixed MB GB selection in new volume creation O More sensible saving loading of Linux encryption settings Added prompt when exiting if volumes are still mounted v00 53 00 BETA 24th April 2005 restricted release Fixed major bug causing the main driver to ignore its queue when large amounts of data were written to an encrypted volume O Improved emergency dismount dismounts faster by cance
27. Software The Original Work or any Derivative Works 5 You Any individual organization or legal entity wishing to use The Software for any purpose 6 Source Code The complete source code including all related build scripts images and components required to build the source code into an executable version 2 Grant of license 1 Subject to the terms and conditions of this licence You are granted a world wide royalty free non exclusive licence to use copy distribute display and modify The Software released under this licence 3 Modifications and Derivative Works 1 The Software may be modified in order to produce Derivative Works subject to the following 1 Derivative Works in executable form must prominently display the notice detailed at Exhibit C whenever the Derivative Work is started and in any display and documentation where copyright is asserted for the Derivative Works 2 Derivative Works may not be named or be identified using any of the names specified in Exhibit D nor use any similar sounding or potentially confusing name 3 Derivative Works may not use any of the names specified at Exhibit D or that of the Original Author to promote or endorse the Derivative Works without the prior written permission of the Original Author 2 Derivative Works in executable form may only be distributed provided that 174 1 Such distributions include a copy of this licence 2 The Source Code used to produce the Derivative Works must be released
28. Windows Mobile 6 Note earlier versions of FreeOTFE4PDA should also work with this OS Added option to revert volume file timestamps attributes to their pre mount values on dismounting Optimised order of cypher hash details returned from drivers to improve time to mount on PDA version Updated LibTomCrypt based cypher hash drivers to use LibTomCrypt v1 17 v2 11 00 29th June 2007 O O O Added prefix to mountpoint passed to configured explorer application when exploring mounted volumes in order to better support 3rd party software e g Resco Explorer Added automatic refresh of FreeOTFE s display if already running when a volume is mounted via the commandline tapping on a vol file Updated to correct minor bug preventing commandline options from mounting correctly if no mountpoint is supplied on the commandline v2 10 00 27th May 2007 O O O O Added optional support for Windows Mobile 5 0 softkeys Documentation layout revamped Added link to user guide from Help menu Made it clearer to the user at which point they can create their new volume and which advanced optional steps v2 00 00 18th March 2007 O O O oo0o0o0o0 Added option to change the default mountpoint or default it based on the volume s filename Mount dialog mountpoint control moved to Advanced tab on mount dialog Added option to specify a different File explorer application Added option to associate FreeOTFE4PDA
29. and XTS AES 256 Portable mode included FreeOTFE doesn t need to be installed before it can be used making it ideal for carrying your data securely on USB drives Security tokens smartcards supported for extra optional security Operates under both PC MS Windows 2000 XP Vista Windows 7 and PDA Windows Mobile 2003 2005 and Windows Mobile 6 platforms Linux compatibility Cryptoloop losetup dm crypt and LUKS supported Hidden volumes may be concealed within other FreeOTFE volumes providing plausible deniability FreeOTFE volumes have no signature to allow them to be identified as such Encrypted volumes can be either file or partition based Modular design allowing 3rd party drivers to be created incorporating new hash cypher algorithms Supports password salting up to 512 bits reducing the risks presented by dictionary attacks Allows users to backup and restore the critical areas of volume files Keyfile support included store volumes and their associated metadata separately Volume file timestamps and attributes are reset after dismounting increasing plausible deniability Supports volumes files up to 2463 bytes 8388608 TB Comprehensive documentation Naturally fully supported by SecureTray Util Plus more Screenshots of FreeOTFE and FreeOTFE4PDA are Cyphers included Key length in bits Block Length in bits Source Library Comments AES 128 128 CBC XTS Dr Brian R G
30. being displayed What are the little shield icons shown next to some menuitems I have problems starting any of the drivers under the 64 bit version of Windows Vista Windows 7 what s wrong 12 1 3 FreeOTFE4PDA Specific PDA I created my volume file using the PDA version of FreeOTFE and can mount it on my PC but why does it keep asking if I want to format it I created a volume on my PC and can mount it successfully on my PDA but can t see any of my files How can I speed FreeOTFE up when mounting my volumes Does the PDA version support Linux volumes Why does FreeOTFE4PDA s version numbering skip from v0 55 to v2 00 what happened to v1 00 Why does FreeOTFE4PDA s version numbering skip from v3 76 to v5 00 what happened to v4 00 When Iuse the open dialog to select my volume file keyfile it doesn t list the file I m trying to specify even when I select All files where is it How can I reduce the amount of storage space FreeOTFE4PDA takes up when installed Why do I get the message Unable to locate local copy of user guide would you like to see the latest version on the Internet when I try to view the user guide by selecting Help User guide When I try to mount a volume I sometimes the error Mount failed the virtual storage device could not be activated at this time Which PDAs will FreeOTFE4PDA work with What does the Support WM 5 0 soft keys option do I don t like t
31. dev loop0O vol_xor Enter password password1234567890ABC mkdosfs dev loop0 mkdir test_mountpoint mount dev loop0 test_mountpoint echo This is a text test file gt test_mountpoint SHORT_TEXT txt umount dev loop0 losetup d dev loop0 rm rf test_mountpoint 55 Mounting the volume under FreeOTFE Select Linux Mount Select the volume file Key tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the Null hash Leave iteration count at 0 Encryption tab Select the XOR cypher Select the Null IV IV generation method The Hash with A s if hash output is too short makes no difference File options tab Leave offset at 0 Leave sizelimit at 0 Mount options tab Select any unused drive letter Leave readonly unchecked Click the OK button 9 8 5 Example 3 Volume Encrypted Using 128 bit AES This example demonstrates use of a Linux AES128 volume Creating the volume file under Linux dd if dev zero of vol_aes128 bs 1k count 1024 losetup e AES128 dev loop0 vol_aes128 Enter password password1234567890ABC mkdosfs dev loop0 mkdir test_mountpoint mount dev loop0 test_mountpoint echo This is a text test file gt test_mountpoint SHORT_TEXT txt umount dev loop0 losetup d dev loop0 rm rf test_mountpoint Mounting
32. dev loop1l dev mapper myMapper mkdosfs dev loopl mkdir test_mountpoint mount dev loopl test_mountpoint 65 cp test_files SHORT_TEXT txt test_mountpoint cp test_files BINARY_ZEROS dat test_mountpoint cp test_files BINARY_ABC_RPTD dat test_mountpoint cp test_files BINARY_OO_FF_RPTD dat test_mountpoint umount test_mountpoint losetup d dev loopl cryptsetup remove myMapper losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume file 3 Key tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the RIPEMD 160 160 512 hash Ensure Hash with A s if hash output is too short is checked Leave iteration count at 0 4 Encryption tab Select the Blowfish CBC 448 64 cypher Select 32 bit sector ID as the IV generation method Set Sector zero location to Start of encrypted data 5 File options tab Leave offset at 0 Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button 9 9 7 Example 5 Volume Encrypted Using 256 bit Twofish and Offset This example demonstrates use of a dm crypt Twofish 256 volume with the encrypted volume beginning at an offset of 3 sectors 3 x 512 1536 bytes into the volume file Creating the volume file under Linux dd if dev
33. drivers are primarily intended to allow verification of the implementations and increase confidence that they re actually doing what it s supposed to do These duplicated drivers do exactly the same thing It is recommended that if you wish to use a cypher which has multiple supplied drivers that you uninstall one of them See also Which of the duplicated drivers should I use Q Which of the duplicated drivers should I use 94 A It doesn t particularly matter too much they both do exactly the same thing but are based on different implementations Simply choose one and uninstall the other Q Can FreeOTFE generate keyfiles which only allow read only access A Not at present though if I receive enough requests for it I may add this functionality Until then it should be borne in mind that anyone with a read only keyfile has pretty much by definition a copy of your master key and so has the potential to modify their read only keyfile turning it into a read write keyfile i e It is debatable how much use this functionality has certainly it should not be relied upon to prevent users from gaining write access to your volume files Q Can I use the same encrypted volumes on both my PC and PDA A Yes you can Both the PC and PDA versions of FreeOTFE are fully compatible with each other However please create your volume using the PC version of FreeOTFE Volumes created using the PDA version will incl
34. encrypted partition image Requested drive letter The drive letter the volume should be normally be mounted as Set to 0x00 if there is no particular drive letter the volume should be mounted as i e mount using the first available drive letter Volume IV length This will be set to the length of the Volume IV in bits If the cypher s blocksize is gt 0 this will be set to the cypher s blocksize Otherwise this will be set to 0 Volume IV If cbs gt 0 then cbs If cbs lt 0 then 0 This is set to the random data generated when the volume was created When each sector of the encrypted partition is encrypted decrypted this value will be XORd with any hashed or unhashed sector ID before being used as the sector IV This guarantees that every sector within the encrypted partition has a non predictable IVs Random padding 2 Random padding data Required to pad out the encrypted block to a multiple of bs and to increase the size of this block to the maximum length that can fit within the critical data block Total size 13 2 2 5 Miscellaneous Comments Regarding the CDB Layout The design of the critical data layout eliminates the need for the cypher hash used to be stored anywhere denying an attacker this information and increasing the amount of work required to attack a volume file The password salt appears before the encrypted block and no indication of th
35. followed by one or more letters will be listed in the open file dialog even if you selected the display All files option Furthermore this dialog will only display those files located in the following places Any subdirectory on a storage card which is located from the root directory of that storage card Files in the My Documents directory on your PDA Files in any subdirectory immediately underneath your My Documents directory The simplest solution is to rename your file and move it into one of the directories indicated above Alternatively you can still specify your file by simply typing its full path and filename into the relevant entry box instead of clicking and using the open file dialog to select it Note that you don t need a filename extension and can store volume key files anywhere on your PDA Conforming to the above restrictions allows you to use the open file dialog to select your files and does not affect FreeOTFE s operation in any way Q How can I reduce the amount of storage space FreeOQTFE4PDA takes up when installed A The easiest way of reducing FreeOTFE4PDA s installed footprint is to delete its user documentation from your PDA i e everything in the docs subdirectory You don t or at least shouldn t really need this documentation as FreeOTFE4PDA is a pretty straightforward application to use and if you do find you want to refer to it occasionally tapping on Hel
36. gui FreeOTFE exe drivercontrol count type total portable installed FreeOTFE exe drivercontrol install filename lt driver filename gt all silent FreeOTFE exe drivercontrol uninstall drivername lt driver name gt all silent e 8 1 2 Description FreeOTFE supports a number of command line options that allow a number of its main functions to be carried out from the command line or via MS Windows shortcuts 8 1 3 Options Note that may be substituted in place of if required Note Although there is currently no option to specify which drive letter a volume should be mounted as this may be set on any given FreeOTFE volume by selecting Tools Change volume keyfile password details Count the number of mounted volumes Exit code indicates the appropriate number or error code see below count create Create new FreeOTFE volume Dismount indicated drive all dismount lt drive letter gt dives Drive letter to be used when i lt i 1 gt Arive gar ive Eee mounting the volume 40 Return count of drivers as exit code total drivers present count installed in portable mode count formally installed If type is not specified type total is assumed drivercontrol count type total portable installed dvivercontrol gui Display driver control dialog Install specified driver or all drivercontrol install filename lt driv
37. it appears to the host OS after mounting If the user opted to additionally use per volume IVs when the volume was created IVs generated using the method selected by the user when the volume was created are XORd with a per volume IV This per volume IV consists of a block of data equal to the blocklength of the cypher used to encrypt the volume and consists of random data generated when the volume was created and stored within the volume s CDB or keyfile 13 6 Registry Entries The PC version of FreeOTFE doesn t create any registry entries for itself unless the user chooses to associate vol files with the application in which case only those registry entries which are required to associate the FreeOTFE executable with the filename extension are created All user options and settings are stored in a ini file unless the user explicitly configures them to be stored in the registry In addition to this MS Windows does create a registry entry for each FreeOTFE driver used This is inevitable all OTFE systems running under MS Windows are required to do this in order to function correctly The following detail the registry entries are typically created by MS Windows Registry key HKEY_LOCAL_MACHINE SYSTEM CurrentControlSet Services lt driver name gt These keys may have the following values under them Value Type Meaning ErrorControl DWORD 0x00000001 Normal error handling 0x00000001 Driver started at syst
38. limited to 512 bits This is limited for practical reasons as some kind of limit is required if the critical data block is to be of a predetermined size See section on mounting volume files for how multiple matching MACs are handled The Password salt is fairly arbitrarily limited to 512 bits Again this is primarily done for practical reasons Although at time of writing March 2005 this limit to the length of salt used should be sufficient the format of the critical data block with included layout version ID does allow future scope for modification in order to allow the critical data block to be extended e g from 4096 to 8192 bits should this limit be deemed inadequate The Encrypted block does contain a certain amount of data that may be reasonably guessed by an attacker e g the CDB format ID however this would be of very limited use to an attacker launching a known plaintext attack as the amount of this data is minimal and as with pretty much any OTFE system the encrypted partition image can reasonably expected to contain significantly more known plaintext than the CDB anyway e g the partition s boot sector 141 13 2 3 5 1 CDB Encryption The encrypted data block within a CDB is encrypted using A key derived from the user s password e ANULLIV The key used for this encryption decryption depends on the CDB format used to create the CDB For older CDB format 1 volumes the key is derived as follows 1 T
39. lock on the associated drive This is normally caused by one or more files being open on the encrypted volume Normal non administrator users may also have problems dismounting drives see the TODO list this documentation If a volume cannot be dismounted normally you will be prompted if you want to forcefully dismount it it is only recommended that volumes are dismounted in this way if all open files and documents are closed Q Why are the drivers written in C but the PC versions GUI in Delphi A Good question The drivers are written in C as the DDK pretty much requires it The PC GUI is in Delphi as this was the easiest for me to implement The PDA version of the GUI was written in C this may be ported to the PC platform at a later date Q Why aren t I prompted to enter a password when creating a Linux volume A This is covered in the documentation see section relating to creating Linux volumes In a nutshell creating a Linux volume only requires a file to be created of the appropriate size It is when the volume is subsequently mounted that a password is required the same process as when creating an encrypted Linux volume under Linux 101 Q Can I burn my volumes on a CD or CDRW or DVD and mount them from there A Yes at the end of the day volume files are just plain straight albeit very large files Just ensure that when you mount them you mount them as read only volumes for obvious reasons even
40. needed when backing up a volume s CDB as the backup copy is not stored in plaintext it is a literal backup copy of a volume s encrypted CDB A password is needed when creating a keyfile as this requires that the volume s CDB is decrypted before being re encrypted with the keyfile s password and written out to the keyfile 11 1 PC Version A This section applies to the PC version of FreeOTFE only DAT After creating a new volume it must be mounted and formatted After this it is highly recommended that you overwrite all the free space on the drive Tools Overwrite free space Linux encryption settings files les files are straightforward text files which contain the settings entered 79 Peter Gutmann s cryptlib may optionally be used as an RNG provided that it has been installed correctly This may be downloaded from www cs auckland ac nz pgut001 cryptlib After installation the cryptlib option will no longer be greyed out on RNG selection dialogs User settings configured via the View Options menu are stored within a configuration file ini file which is located in the same directory the FreeOTFE executable is launched from User options are not stored within the registry unless configured to store them in it By storing user settings in a separate file as opposed to the registry FreeOTFE achieves two things 1 If FreeOTFE is stored on removable media e g a USB flash drive CD
41. not prevent a reasonably knowledgeable IT person from being able to reasonably identify an encrypted volume as such like any security mechanism padding is simply another tool which would be employed from a larger toolbox For this reason it is not recommended that padding be relied upon to help secure data against an attacker and users considering using padding may benefit from reading the section on Plausible Deniability 100 Q Why wouldn t I want to use padding A Padding takes up additional storage on your hard drive beyond that required by the volume file 12 3 FreeOTFE Specific PC Q When creating a FreeOTFE volume the wizard shows me which stage of volume creation I am currently on but it goes haywire and the number of stages to complete keeps changing A The number of different stages to creating a new FreeOTFE volume varies depending on what options you choose for example if you elect to the mouse movement to generate random data then you will have to complete an extra step to actually generate this random data if you switch to using the Microsoft CryptoAPI for generating random data you can skip that step as it is done for you automatically Q Is it possible to dismount my FreeOTFE volumes when I hit a certain hotkey A Yes see under View Options the Hotkeys tab Q Why can t I dismount my volume s A The most common reason for this is because FreeOTFE cannot gain an exclusive
42. remove myMapper losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume file 3 Key tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the RIPEMD 160 160 512 hash Ensure Hash with A s if hash output is too short is checked Leave iteration count at 0 4 Encryption tab Select the AES CBC 128 128 cypher Select 32 bit sector ID as the IV generation method Set Sector zero location to Start of encrypted data 5 File options tab Leave offset at 0 Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button 9 9 5 Example 3 Volume Encrypted Using 256 bit AES using SHA256 ESSIV This example demonstrates use of a dm crypt AES256 volume using SHA 256 ESSIV sector IVs Creating the volume file under Linux dd if dev zero of volumes vol_aes_essiv_sha256 vol bs 1K count 100 losetup dev loop0O volumes vol_aes_essiv_sha256 vol echo password1234567890ABC cryptsetup c aes cbhc essiv sha256 create myMapper dev loop0 dmsetup 1s dmsetup table dmsetup status losetup dev loopl dev mapper myMapper 64 mkdosfs dev loopl mkdir test_mountpoint mount dev loopl test_mountpoint cp test_files SHORT_TEXT txt test_mountpoint cp test_files BINARY_ZEROS dat test_m
43. reverting functionality in order for your backup software to identify when volumes have been changed See View Options dialog General tab Revert volume timestamps on dismount For disk partition based volumes Whether you can backup disk partition based volumes depends on the backup software being used If your backup software takes a literal backup image of a disk partition then it should successfully backup FreeOTFE volumes even if the backup copy is compressed However not all backup systems do this and instead try to be smart about what they store to backup and fail to backup everything they need to This issue is true for all disk encryption systems not just FreeOTFE For example with Paragon Drive Backup if you create an encrypted volume using an entire disk i e without creating a partition on the disk and encrypting that partition Paragon Drive doesn t appear to think there s anything worth backing up i e it doesn t see any partitions to backup and therefore backs up practically nothing As a result it will not back up your volume correctly However If you create an encrypted volume on a partition even one filling the entire drive and back that partition up Paragon Drive Backup does what it should do generates a compressed backup copy of the entire partition which can then be restored back later 98 No matter what you re backing up when you setup a backup system for the first time
44. running under Windows Vista and later it is not relevant for other operating systems A To prevent the UAC dialogs from being shown when using FreeOTFE and all other applications you can disable it by carrying out the following steps 1 Click on the Start button and then select Control Panel 2 Doubleclick User Accounts 3 Click on Turn User Account Control on or off 4 Make sure that the Use User Account Control UAC checkbox is unchecked 5 Click OK 6 Restart your computer Q Windows Vista only I have problems starting any of the drivers under the 64 bit version of Windows Vista Windows 7 what s wrong This FAQ is only applicable when running under Windows Vista and later it is not relevant for other operating systems A The 64 bit versions of MS Windows Vista and MS Windows 7 both use driver signing please see the section on installing FreeOTFE on Windows Vista x64 and Windows 7 x64 115 Q Windows Vista only What are the little shield icons shown next to some menuitems This FAQ is only applicable when running under Windows Vista and later it is not relevant for other operating systems A Functions marked with a shield icon require Administrator privileges in order to use them for security reasons This is for your security and more information can be found on the Microsoft WWW 12 4 FreeOTFE4PDA Specific PDA Q I created my volume file using the PDA version of FreeOTFE
45. sector ID possibly hashed as IV 1 Sector ID zero is at the start of the file 0 Sector ID zero is at the start of the encrypted data 1 Sector ID zero is at the start of the host volume file 2 lt unused gt 3 Hash sector ID before use 0 Sector ID used as IV 1 Hash sector ID before using is as an IV Encrypted partition image length This stores the length in bytes of the encrypted partition image Master key length 32 This will be set to the length of the master key in bits Not strictly needed but used as a sanity check Master key ks max 1536 This is set to the random data generated when the volume was created it represents the en decryption key used to encrypt the encrypted partition image Requested drive letter The drive letter the volume should be typically be mounted as Set to 0x00 if there is no particular drive letter the volume should be mounted as mount using the first available drive letter Random padding 2 All remaining bits to pad out to Total size Random padding data Required to pad out the encrypted block to a multiple of bs and to increase the size of this block to the maximum length that can fit within the critical data block Total size 4096 sl bs bs hk Note represents integer division 127 13 2 1 6 Miscellaneous Comments Regarding the FreeOTFE Volume File Layout The design of the critical data layou
46. seznam cz Japanese Hiroaki Ohtsuka hgc00566 nifty ne jp Croatian Zlatko Zivkovic zzivkovic cogeco ca Greek Geogeo geogeo64 yahoo gr Russian Dmitry Yerokhin erodim mail ru 173 19 Appendix C Licence 19 1 Preamble The following licence covers FreeOTFE FreeOTFE4PDA and FreeOTFE Explorer including source executables documentation and all related with the exception of the files stored in the source release under the src 3rd_party directory which are covered by the separate licences included with them e g libtomcrypt is public domain software Twofish is uncopyrighted and license free The primary purposes of this licence are 1 To ensure that any improvements made to FreeOTFE FreeOTFE4PDA FreeOTFE Explorer can always be incorporated into the main releases 2 To ensure proper credit is given to these projects 3 To protect against modified versions of the software claiming to be FreeOTFE FreeOTFE4PDA FreeOTFE Explorer or be named such that they may be confused with them 19 2 FreeOTFE Licence v1 1 1 Definitions 1 Original Author The individual organization or legal entity identified in Exhibit A 2 Original Work The Source Code documentation and built executables relating to the software identified in Exhibit B 3 Derivative Works Any modified version of the Original Work or product which uses any part of the Original Work and any subsequent Derivative Works 4 The
47. support for dropping keyfiles onto the password entry dialog to simplify keyfile filename entry Added automatic check for updates turned off by default Allow option to change the default mount type used Allow various options to turn on off confirmation warning messages Allow users to mount volumes as A or B if these drive letters aren t in use Note Selecting Use default for the drive to mount as will still result in using the first unused drive letter after C A B may only be used if explicitly selected by the user 163 O00 0 O O O O Added support for refresh multimedia key Added create command line option for creating new volumes Added settings command line parameter to read options from user specified location Created U3 and portableapps com specific installers simplifying installation for users of these particular systems Removed restriction requiring hidden volumes to begin at an offset which is a multiple of 512 bytes Allow mounting either Linux LUKS or FreeOTFE partitions via the Partition toolbar button and File Mount partition menuitem previously only FreeOTFE partitions could be mounted this way Fixed minor bug which prevented hidden volumes from being automatically mounted after being created Fixed minor bug with minimise to system tray functionality Fixed bug causing main window to resize continuously if toolbar not shown v4 71 19th April 2009 O O O O Added s
48. that the Hash with A s if hash output is too short is not checked Leave iteration count at 0 4 Encryption tab Select the Twofish CBC 256 128 cypher Select the 32 bits sector IV IV generation method Set Sector zero location to Start of host file 5 File options tab Leave offset at 0 Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button 9 9 Examples dm crypt This section gives a series of examples of how to create Linux dm crypt volumes and then mount them using FreeOTFE These examples have been tested using Fedora Core 3 with a v2 6 11 7 kernel installed though they should work for all compatible Linux distributions 9 9 1 Initial Setup To begin using dm crypt under Linux ensure that the various kernel modules are installed 61 modprobe modprobe modprobe modprobe modprobe modprobe modprobe modprobe modprobe modprobe modprobe modprobe modprobe modprobe modprobe modprobe modprobe modprobe modprobe modprobe At this point crypt striped linear error cryptoloop deflate zlib_deflate twofish serpent aes_i586 blowfish des sha256 sha512 crypto_null md5 md4 cast5 cast6 arc4 khazad anubis dm_mod this should give you dm_snapshot dm_zero and dm_mirror dm_crypt typing dmsetup targets should give you something along the lines of lt lt lt Pree OD Oo PR
49. the Microsoft WWW site 114 Q Windows Vista only Why does FreeOTFE prompt me to enter my Administrator s password This FAQ is only applicable when running under Windows Vista and later it is not relevant for other operating systems A FreeOTFE doesn t ask you to enter an Administrator s password it has no use or need for this information Windows Vista however will prompt you to enter an Administrator s password whenever you are logged in as a standard i e non Administrator user and attempt to carry out any operation which it deems could be harmful to your computer If you are happy for FreeOTFE to carry out the operation you requested of it you should select the relevant option from the consent credential dialog and enter the appropriate Administrator s password to allow FreeOTFE to proceed Those operations which require Administrator s explicit approval before Windows Vista will permit you to carry them out are marked in FreeOTFE with a shield icon It should be emphasised that it is Windows Vista itself which is generating these prompts and not FreeOTFE which will have no access to the password you type in These prompts form part of Windows Vista s User Access Control UAC system which you can find out more about from the Microsoft WWW site Q Windows Vista only How do I stop the Windows Vista consent credential UAC dialog from being displayed This FAQ is only applicable when
50. the cypher selected e parameter passed as losetup can support different keysizes e g AES supports 128 192 256 bit keysizes and the user doesn t specify the keysize to be used i e you specify e AES as opposed to e AES128 then the cypher will default to using 128 bit keys From http aes sourcefor 9 5 dm crypt Specific Information 9 5 1 dev loop1 Usage in the Examples Included in this Documentation The examples shown in this documentation include the slightly odd step of losetup dev loopl dev mapper myMapper mkdosfs dev loop1 as opposed to just straight mkdosfs dev mapper myMapper This is carried out as in my tests the latter appears to result in failure 49 mkdosfs dev mapper myMapper mkdosfs 2 8 28 Feb 2001 mkdosfs unable to get drive geometry for dev mapper myMapper 9 5 2 Hash Selection If an attempt is made to mount a volume using a cypher with a larger keysize than the hash algorithm used to processes the user s password dm crypt appears to use the following algorithm to generate the actual encryption decryption key used by the cypher 1 The user s password is hashed 2 If the hash output contains fewer bits than the cypher s keysize the capital letter A is prepended to the user s password and a new hash is generated 3 This second hash is appended to the previous one 4 If the total hash output contains fewer bits than the cypher s keysize another
51. the format of the critical data block with included layout version ID does allow future scope for modification in order to allow the critical data block to be extended e g from 4096 to 8192 bits should this limit be determined as insufficient The Encrypted block does contain a certain amount of data that may be reasonably guessed by an attacker e g the critical data version however this would be of very limited use to an attacker launching a known plaintext attack as the amount of this data is minimal and as with pretty much any OTFE system the Encrypted partition image can reasonably expected to contain significantly more known plaintext anyway e g the partition s boot sector 13 2 1 7 Creating FreeOTFE Volumes To create a FreeOTFE volume file a fairly significant amount of information is required due to freedom that FreeOTFE gives you in creating volume files Broadly speaking creating a FreeOTFE volume consists of three distinct stages 1 Creating a file large enough on the local filesystem 2 Writing the critical data block to the volume file 3 Mounting the volume formatting it and shredding overwriting all free space Stage 1 is straightforward write data to the file until is has gained the required size This stage is skipped in the case of creating a hidden volume Stage 2 is more complex and will be described below Stage 3 is required in set the volume up for use and increase security 128
52. the point it was rebooted to be recovered it should also be noted that any information that applications had in memory at the time the computer is reset e g a document open in MS Word or image being displayed on the screen may potentially be recovered Disk encryption systems encrypt data stored on disks not in RAM Q Does FreeOTFE have any form of password recovery A Yes FreeOTFE keyfiles can be used to provide a form of password recovery see the Getting Started Guide Q Isn t FreeOTFE s keyfile functionality a security risk A No In order to create a keyfile both the volume and the volume s password or an existing keyfile and that keyfiles password are required If an attacker already has this information your security has already been compromised anyway Q What happened to the NULL hash and NULL XOR cypher drivers A To improve performance these drivers have been moved into a weak drivers directory in the PDA release Really you shouldn t be using these drivers at all they are of little use from a security perspective and are only really included to allow testing They re still included with the release though if you really need them Q How do I resize an encrypted volume A To change the size of an encrypted volume 1 Mount your existing volume 2 Create a new FreeOTFE volume of the size required 3 Mount the new volume overwriting and formatting it if needed 4 Copy all data
53. the so called free version is severely crippled only permitting 35 MB volumes In the case of LockDisk it s based on a pretty old and now obsolete v0 59 BETA version of FreeOTFE And for all this you have to pay for them I could list another few dozen reasons for not using these products but I think you get the picture FreeOTFE is simply better Q How can I be sure that there are no backdoors in FreeOTFE A Review the source code to your satisfaction and build your own see section Building FreeOTFE This is strongly recommended and the best way of ensuring that the software is not compromised 89 However this is not always practical many people are not familiar with how to read source code or lack the required tools to build their own In which case if you trust the author and the system on which the release was built on then you may prefer to simply check the SHA 1 and PGP signatures associated with the binary release Q Do FreeOTFE volumes have any kind of identifying signature A No Please see the FAQ By examining a FreeOTFE encrypted Linux volume file can anyone tell what it fis for further information Q By examining a FreeOTFE encrypted Linux volume file can anyone tell what it is A Neither FreeOTFE nor encrypted Linux volumes have any kind of signature that would allow an attacker to identify them for what they are In particular the critical data block in every FreeOTFE vol
54. things 1 A critical data block CDB 2 An encrypted partition image The CDB may either form part of the volume in which case it is prepended to the encrypted partition image or it may be stored as a separate file in which case it is referred to as a keyfile Users may create any number of keyfiles for any given volume To create a new keyfile the user must supply either 1 An existing keyfile and its password etc 2 A volume file which has a CDB together with its password salt length etc The keyfile or volume CDB supplied will then be read in decrypted and re encrypted with a new password salt length etc all supplied by the user before being written out as the new keyfile A full definition of the contents of a CDB keyfile is supplied in this documentation 13 1 1 Notes A FreeOTFE keyfile is nothing more than a CDB the volume details block of which contains the encryption details used for securing the volume it relates to A volume may have one or more keyfiles in which case they all share the same data stored within their respective volume details block but each one is encrypted with a different user password salt random padding etc making each keyfile unique Keyfiles are encrypted with the same cypher hash that the encrypted partition image they relate to is encrypted with 13 2 Technical Details Critical Data Block Layouts Please select which CDB Format you would like information on
55. though I have no intention in turning FreeOTFE into a commercial product The nearest that I may do is request donations This would of course be fully voluntary Q FreeOTFE may always be free but will an enhanced version which is charged for with extra features be released perhaps under a different name A Personally this sounds a lot like the selling out idea above if such a paid for version was to be released FreeOTFE development may become at risk of stalling ceasing completely or omitting particularly useful features This would have practically the same effect as making FreeOTFE a paid for commercial system Q What about klonsoft s LockDisk and WinCrypto LLC s CryptoDisk Aren t they paid for packages which are based on FreeOTFE A Both LockDisk and CryptoDisk are unlicensed and unlicensable commercial rip offs of FreeOTFE They are based on FreeOTFE s source code and only a beta version at that in the case of LockDisk and because they are closed source are in direct violation of FreeOTFE s licence I have nothing to do with either LockDisk or CryptoDisk nor any involvement in their creation Personally I would strongly recommend against using these products They have less functionality than FreeOTFE They re closed source there s no way of knowing how secure it is or what it does It is not possible to legally obtain a licence for these products In the case of LockDisk
56. to the list Manufacturer Device Library Notes For use with ACOSS smartcards ACOSS smartcards unable to ACOSS5 opke create data objects and smartcards contain no mechanisms for creating secret keys except public private keypairs aka StarSign Middleware Also installs PKCS 11 Rainbow iKey drivers aetpksse dll 3000 series and Entrust PKCS 11 lib G amp D StarCos 2 3 aetpkSS Lall and aetpkssw dll SPK cards PKCS 11 library wrapper that detects the need for automatic login on aetpkss1 dll eToken PRO etpkes1 1 dll Confirmed working Aladdin with FreeOTFE eToken R2 etpkcs11 dll Algorithmic Research MiniKey sadaptor dll 177 Smart Card Connector aloaha_pkcs11 dll Not fully tested but from initial checks this library appears badly broken it reports tokens present when no card reader is installed When creating data objects on the phantom token it reports that the objects were successfully created but doesn t actually do anything Possible that it works correctly if both hardware and token present A Sign A Sign premium cards psepkcs11 dll Reputedly v1 0 of this library is incomplete and has many bugs Athena Athena Smartcard System ASE Card asepkcs dll A Trust a sign asignp11 dll Belgian Government Belgian Electronic Identity eID Card Belgium Identity Card PKCS11 dll Chrysalis cryst32 dll WWW site no
57. under this licence 3 The Source Code used to produce the Derivative Works must be made freely available to anyone who wishes a copy including but not limited to the Original Author and any recipient of the Derivative Works for a minimum period starting from the time at which the Derivative Works are initially distributed to at least two years after the Derivative Works cease to be distributed 4 Termination 1 This licence terminates automatically should You 1 Fail to comply with any of the term of this license 2 Commence any action including claim cross claim or counterclaim against the Original Author 5 Disclaimer of Warranty 1 THE SOFTWARE COMES WITH NO WARRANTY OF ANY KIND EITHER EXPRESS OR IMPLIED 19 2 1 Exhibit A The Original Author is Sarah Dean 19 2 2 Exhibit B The works covered by this licence are FreeOTFE FreeOTFE4PDA FreeOTFE Explorer 19 2 3 Exhibit C The notice to be shown is This software is based on FreeOTFE and or FreeOTFE4PDA the free disk encryption system for PCs and PDAs available atl www FreeOTFE org 19 2 4 Exhibit D The restricted names are FreeOTFE FreeOTFE4PDA FreeOTFE Explorer 175 20 Appendix D Glossary CDB Acronym Critical Data Block See Critical Data Block Critical Data Block AKA CDB A block of data holding data vital to the correct mounting and use of an encrypted partition volume Among other things a volume s CDB contains the master key
58. used during volume creation the user is also be prompted to enter the size of the salt used in bits Call this value sl e The offset within the file where the critical data block is located Typically this will be zero unless a hidden volume is to be accessed see information on hidden volumes The first 512 bytes 4096 bits of the file are read in beginning from the user specified offset The first sl bits of which are assumed to be the salt and are appended to the user s password For each hash algorithm installed on the user s computer Note We will use hk to describe the length of hash values generated by each hash algorithm as it is used in turn This value is as reported by the hash driver If the hash driver reports that the hash length 1 we will use the smaller of 512 bits and the length of the data that the hash algorithm actually returns as hk 1 The combined user s password and salt previously generated is hashed giving an hk bit critical key 2 For each cypher installed on the user s computer Note We will use ks to describe the keysize of each cypher as it is used in turn the keysize being as reported by the cypher driver If the cypher driver reports that the cypher s keysize is 1 no specific keysize we will use hk as ks Note We will use bs to describe the blocksize of the cypher as reported by the cypher driver If the cypher driver reports that the cypher s keysize is 1 no bl
59. used for encrypting decrypting data as it is written read from a the volume CDBs are encrypted A full description of what FreeOTFE stores in its CDBs can be found in the Technical Details section LES file Linux Encryption Settings file a text file in which encryption settings for Linux volumes are held Created by using the Load Save buttons on the password entry dialog when mounting Linux volumes OTFE Acronym On The Fly Encryption Any of a number of encryption systems where data is stored on disk in encrypted format When it is read in from disk it is transparently decrypted on the fly before user applications receive it In a similar manner when applications etc write data back to the disk it is automatically encrypted before being written 176 21 Appendix E PKCS 11 Driver Libraries If you have a token which supports the PKCS 11 standard as most do your token can be used by FreeOTFE Below is a list of well known smartcards tokens which do support this standard and the suggested library filename to use Please note that 1 Token manufacturers may change their driver filenames without notice check with your supplier if the information listed below doesn t work 2 This list is not exhaustive many more tokens are supported than are listed here If you are using a token which isn t mentioned on the list below please check with your token supplier as to what to enter and get in touch to have it added
60. with the user s password to derive the Password salt User specified critical data key This key is then used to encrypt decrypt the to a max 512 Encrypted block If cbs gt 8 then CDL sl div cbs cbs If cbs lt 8 then CDL sl This block contains the actual key which is used to Encrypted encrypt decrypt the encrypted partition image block ae See below for further breakdown This size is referred to as leb Random Random padding data Required to pad out any remaining CDL sl leb padding 1 unused bits in the critical data block Total size CDL 13 2 2 3 Breakdown Encrypted block layout Check MAC Random padding 3 Volume details block As described above this entire block is encrypted using the user s password salt and chosen hash and cypher algorithms As this block is encrypted its length in bits must be a multiple of the cypher s blocksize 133 Item name Size in bits Description This is the MAC of the plaintext version of the Volume details block ml Check MAC Up to a maximum If hk is zero or undefined then this hash will be either truncated of MML bits to MML bits or right padded with 0 bits up to a maximum of MML bits Random Random padding data Required to pad out the check MAC to padding 3 a predetermined number of bits Volume This stores the details of how to encrypt decrypt the encrypted details part
61. with volume files Added context menu option to explore mounted volumes in addition to existing doubletap explore Added option to backup and restore the CDB from volumes with a CDB Added option to dump critical data block to a human readable file Added command line support Added OS version ID to human readable CDB dumps Moved weaker drivers FreeOTFE4PDAHashNull dll FreeOTFE4PDACypherNull dll and FreeOTFE4PDACypherXOR dll into a weak drivers directory most users shouldn t use these drivers but they re still included in the release if needed v0 55 00 BETA 4th December 2006 O O Corrected error preventing volumes encrypted with the XOR and NULL encryption drivers operating properly Corrected problem with opening files on some PDAs 171 O Redundant drivers moved into separate directory O Added further information to documentation with respect to redundant drivers speeding up the time taken to mount Added stats report for drivers developer use only O FreeOTFE4PDACypherTwofish_HifnCS dll driver removed from PDA binary distribution driver fails to init correctly Note Existing volumes can still be mounted and used with the remaining two Twofish implementations v0 50 00 BETA 11th November 2006 First public release 172 18 Appendix B Credits Thanks go to Tom St Denis tomstdenis iahu ca for the LibTomCrypt library http libtomcrypt org Hi fn and Counterpane Systems for the optimised ref
62. 001 The binary release of this software was built with Microsoft Visual Studio 2005 Professional Edition At time of writing the MS Windows SDK can be downloaded from the Microsoft WWW site The MS Windows DDK is not available as a download but can be ordered from the Microsoft WWW site as a free CD for the cost of delivery It should be noted that if you are unable to source the exact versions listed above earlier versions may well be substituted although I cannot guarantee success Later versions should operate correctly The above list describes the development environment as used to build the binary release of FreeOTFE 13 9 1 2 1 Setting up the Build Environment 13 9 1 2 1 1 Installation and Configuration of MS Build Environment The following list comprehensively describes the configuration used to build the binary release of FreeOTFE Feel free to adjust according to taste a number of the options listed are not necessary and are only included for completeness 1 Install VC 2 Put a copy of vcvarsall bat into one of the directories in your path 3 Configure the VC editor To use spaces not tabs To indent braces 4 Install the MS Windows SDK with the following options Install in C MSSDK Install the Core SDK e Then install the debugging tools for windows Do not register environment variables we ll use Setenv bat from the command line 5 Install the MS Windows DDK with the following options Inst
63. 0D846 the RIPEMD 160 hash of Apassword1234567890ABC If Blowfish 448 bit key is used for encryption decryption and the user s password is processed with MDS the actual encryption decryption key will be 50 4EAB90A0D00CE008 6EB5 9DA838CC888DD1270498F52EFFA5 62872664BB514F8E2FA054980C9D92542F5801FDF82ADFEA121E58 7A4EEBDF3B This is made up as follows 7 The first 128 bits are the MDS hash of EAB 90AO0D0O0CE0086EB5 9DA838CC888D password 1234567890ABC E 7 The next 128 bits are the MDS hash of D1270498F52EFFA562872664BB514F8E Apassword1234567890ABC The next 128 bits are the MDS5 hash of 054980C9D92542F 5801F DE 82ADF B A Apassword1234567890ABC The remaining bits are the first 64 bits taken from the MD5 BEBDE SBD OCD437A1B2C324 hash of AAApassword1234567890A BC 9 5 3 ESSIV dm crypt s ESSIV functionality is available with v2 6 10 and later Linux kernels The manner in which Linux uses ESSIV differs from FreeOTFE volumes in how the ESSIV encryption key is generated Both hash the master encryption decryption key to generate the key used for ESSIV however dm crypt uses the full hash output as the ESSIV key This means that if you have a dm crypt volume which is encrypted using 256 bit AES and specify MD5 as the ESSIV hash the ESSIV process will actually use AES 128 for creating the salt for ESSIV IVs MD5 generates 128 bit hashes It is
64. 13 2 1 8 Writing the critical data block The following procedure is used to build up a FreeOTFE s critical volume block 1 Obtain all the information which will be stored within the volume s Volume details block 2 The following information is determined 11 12 13 14 15 1 sl The number of salt bits required by the user 2 ks The keysize in bits of the user s chosen cypher If the cypher driver reports that this value is 1 then ks should be assumed to be 8 bits 3 bs The blocksize in bits of the user s chosen cypher If the cypher driver reports that this value is 1 then bs should be assumed to be 8 bits 4 hk The length in bits of hashes generated by the user s chosen hash algorithm If the hash driver reports that this value is 1 then hk should be assumed to be 512 bits Build the Volume details block in memory The length of this block in bits is calculated as 4096 sl bs bs hk See the layout breakdown diagrams of the Critical data area to understand where this algorithm comes from With the user s selection of hash algorithm hash the Volume details block to generate the Check hash If the Check hash generated has less than hk bits it should be right padded with zero bits until it is hk bits long If the Check hash generated has more than hk bits it should be truncated to the first hk bits Prepen
65. 256 bit Twofish 9 9 Examples dm crypt 9o Matal Sen 9 9 2 Defaults 9 9 3 Example 1 Volume Encrypted Using dm cryp s Default Encryption 9 9 4 9 9 5 Example wD Volume Encrypted Using g 128 bit AES Example 3 Volume Encrypted Using 256 bit AES using SHA256 ESSIV 38 39 40 40 40 40 40 43 43 44 44 45 45 46 46 47 47 48 48 48 49 49 49 49 49 50 51 51 51 52 52 52 53 53 54 54 54 55 56 57 58 59 60 60 61 61 62 62 63 64 9 9 6 Example 4 Volume Encrypted Using 448 bit Blowfish i 65 9 9 7 E he i eaa S06 9 9 8 Example 6 Volume Encrypted Using g 256 bit AES with MD5 Sawn Hashing 67 9 9 9 Example 7 Volume Encrypted Using 448 bit Blowfish MD5 Password Hashing a 68 9 9 Example 8 Volume Ererypied Using AES 256 in KTS Mode aka XTS AESA 69 9 10 Examples LUKS 70 9 10 Teal Sou ee ee a ae a en eer 9 10 2 Defaults E a fe ate EL 9 10 Example T Volume Enerypled Using LUK S s Default Encryption SS oe a 9 10 4 Example WD Volume Encrypted Using 256 bit AES bu oR ee ee 2 9 10 5 Example 3 Volume Encrypted Using 128 bit Twofish Ae hl ge te vot ae SES 9 10 6 Example 4 Volume Encrypted Using 256 bit AES XTS we we B 9 10 Example SS Volume Unerypied Using 256 hit Serpent XTS Bae Se 2 og TA 10 Plausible Deniabiliy a Se p A6 10 1 Beak hose de fe Meh ie aS phd Sow oe ee as et 0 10 Je a ke BM 8 me p we e a A a a e 10 3 Ta ee a e en ee E 10
66. 29 29 30 30 31 33 34 35 35 36 36 37 37 7 4 PIN Entry 74 Secure auremtication pati 8 Command Line Interface 8 1 PC Version rn 8 1 2 Description 8 1 3 Options 8 1 4 Exit Codes 8 1 5 Examples 8 2 PDA Version 8 2 1 Synopsisl 8 2 2 Description 8 2 3 Options 8 2 4 Exit Codes 8 2 5 Examples ina Volumes 9 1 Creating Linux Volumes _ 9 2 Hiding a Linux Volume Within Another Volume 9 3 Mounting Volumes Created under Linux 9 4 Cryptoloop Specific Information 9 4 1 Hash Selection _ 94 2 Crppoloop and RIPEMD 160 9 4 3 Cypher Selection 9 5 dm crypt Specific Information 9 5 1 dev oop Usage in the Examples nee in Wis Documentation 9 5 2 Hash Selection 9 5 3 ESSIV 9 6 LUKS Specific Information 9 6 1 ESSIV 9 6 2 FreeOTFE Supported LUKS Cyphers boat 9 6 3 FreeOTFE Supported LUKS Cypher modes 9 6 4 FreeOTFE Supported LUKS hashes o7 Additional Noles on Linux Varnes 9 8 Examples Cryptoloop 2 8 ial Serup 9 8 2 Defaults 9 8 3 Example 1 Volume Without Encryption 9 8 41E xample Volume Encrypted Using XORI 9 8 5 Example 3 Volume Encrypted Using 128 bit AES 9 8 6 Example 4 Volume Encrypted Using 256 bit AES 9 8 Example 5 Volume Encrypted Using 256 bit AES and rmd160 Hash 9 8 8 Example 6 Volume Encrypted Using 256 bit AES and Seed Value 9 8 9 Example 7 Volume Encrypted Using 256 bit AES ae Offset 58 LOE xample 8 olume Encrypted Using
67. 2kSZ0OM6zCXqgErlek3Jd4xYy W CxJHtXjLEg5Sy2XMam4 5qKC6CmKcFwJJiVufWSWSCqqVYG30 f 9g1lw4 4AYmn VCIXx t 6ygcr6JABEYEGBECAAYFA jekay4ACgkQLdjfvvrOepdPnACglHGvpsdlEQkb8VZc rWbomoZyMLoYAoPBIVMIiYkdWD2t0cKaR de8Rict Hejr ears END PGP PUBLIC KEY BLOCK 186
68. Advanced Topics under Enabling Disabling Hash Cypher Algorithms Q I would like to use hash cypher XYZ why doesn t it appear as an option A The most likely reason is that XYZ has been disabled within FreeOTFE4PDA please see Advanced Topics Enabling Disabling Hash Cypher Algorithms section for how to enable disable hash cypher algorithms and show XYZ as an option Q How to I enable hash cypher XYZ A See Advanced Topics Enabling Disabling Hash Cypher Algorithms section 12 5 FreeOTFE Explorer Specific Q Does FreeOTFE Explorer support drag and drop with MS Windows Explorer A Yes FreeOTFE Explorer supports dragging files and folders from MS Windows Explorer to FreeOTFE Explorer but doesn t currently support dragging files from FreeOTFE Explorer to MS Windows Explorer Q What filesystems does FreeOTFE Explorer support 121 A FreeOTFE Explorer supports volumes using the FAT12 FAT16 and FAT32 filesystems Support for other filesystems is currently under development Q Does FreeOTFE Explorer try to connect to the internet A No not unless you configure it to do so see the FAQ Does FreeOTFE try to connect to the niemer Q How do I securely overwrite files stored on a flash drive A FreeOTFE Explorer includes optional functionality to overwrite files as they are moved into an encrypted volume or on demand to destroy plaintext non secured copies This works well for destro
69. CDB Format ID 1 obsolete CDB Format ID 2 obsolete CDB Format ID 3 obsolete CDB Format ID 4 123 13 2 1 CDB Format ID 1 NOTE This CDB layout is obsolete all new volumes should use the latest CDB format 13 2 1 1 Overview The following table describes the high level layout of all FreeOTFE not Linux volume files Critical data block Encrypted block Volume details block Encrypted partition image Random padding 1 Password salt Critical data version Encrypted Volume partition image length Requested Random drive letter Color key Encryption used Red items are not encrypted Blue items are encrypted with the user s password password salt and user s chosen hash cypher algorithms Green items are encrypted with the master key and the user s chosen cypher with IVs generated with the user s chosen sector IV method Seem intimidating Read on and all will become clear When broken down into its component parts the volume structure is reasonably straightforward to understand 13 2 1 2 Breakdown Top level Critical data block Encrypted partition image At the highest level volume files can be broken down into just two basic parts A critical data area and the encrypted partition itself 124 Item name Size in bits Description Critical data block This part of the volume file contains critical data including the master en dec
70. E CDB Critical data block Encrypted block Volume details block Random an Ae Encrypted padding Volume partition Master 1 tormat flags image ke ID gs g y letter length Color key Encryption used Red items are not encrypted Blue items are encrypted with the user s chosen cypher together with a critical data key derived from the user s password salt and the user s chosen hash algorithm Seem intimidating Read on and all will become clear When broken down into its component parts the CDB structure is reasonably straightforward to understand Note Throughout this document the following definitions apply Variable Definition Critical Data Length in bits EDE This is defined as 4096 bits Maximum MAC Length in bits MME This is defined as 512 bits Salt length in bits This is the user specified salt length as specified by the user when the CDB is created Cypher Block Size in bits The block size of the cypher used to encrypt the volume Cypher Key Size in bits The key size of the cypher used to encrypt the volume If the cypher accepts variable length keysizes this is set to a user specified value up to a maximum of 512 MAC length in bits This is the length of MAC generated 132 13 2 2 2 Breakdown CDB layout Encrypted block Random padding 1 Item name Size in bits Description sl This data is used together
71. E volume FreeOTFE exe mount volume C My Private Data my encrypted volume dat freeotfe 43 Mounting a Linux volume readonly FreeOTFE exe mount volume C My Private Data my encrypted volume dat linux readonly Mounting a FreeOTFE partition FreeOTFE exe mount volume Device Harddisk0 Partitionl freeotfe readonly Dismount drive S FreeOTFE exe dismount S Dismount all volumes emergency FreeOTFE exe dismount all force Start and stop portable mode FreeOTFE exe portable startFreeOTFE exe portable stop Installing drivers except Windows Vista FreeOTFE exe drivercontrol install filename FreeOTFE sys FreeOTFE exe drivercontrol install filename FreeOTFEHashSHA sys FreeOTFE exe drivercontrol install filename FreeOTFECypherAES_ltc sys Installing drivers Windows Vista runas user myAdminAccount FreeOTFE exe drivercontrol install filename FreeOTFE sys runas user myAdminAccount FreeOTFE exe drivercontrol install filename FreeOTFEHashSHA sys runas user myAdminAccount FreeOTFE exe drivercontrol install filename FreeOTFECypherAES_ltc sys Uninstalling drivers except Windows Vista Hy FreeOTFE exe drivercontrol uninstall drivername FreeO FreeOTFE exe drivercontrol uninstall drivername FreeOTFEHashSHA FreeOTFE exe drivercontrol uninstall drivername FreeOTFECypherA To PA n
72. Explorer release and the PortableApps com version What is the difference between the main FreeOTFE FreeOTFE Explorer release and the U3 version When dismounting a file based volume what does FreeOTFE do with the file timestamps What is volume padding and why would I want it Why wouldn t I want to use padding 12 1 2 FreeOTFE Specific PC When creating a FreeOTFE volume the wizard shows me which stage of volume creation I am currently on but it goes haywire and the number of stages to complete keeps changing Is it possible to dismount my FreeOTFE volumes when I hit a certain hotkey Why can t I dismount my volume s Why are the drivers written in C but the GUI in Delphi Why aren t I prompted to enter a password when creating a Linux volume Can I burn my volumes on a CD or CDRW or DVD and mount them from there Can I use FreeOTFE over a network Why do I get Unable to connect to the FreeOTFE driver errors Why do I get prompted to select a driver whenever I attempt to mount some of my FreeOTFE volume Do I need Administrator privileges to use FreeOTFE on my computer 83 Why do I need Administrator rights to install FreeOTFE Why do I need Administrator rights to start portable mode Can FreeOTFE run under MS Windows 95 98 Me Can FreeOTFE run under Linux How can I get FreeOTFE to mount my volumes at startup when I login On the options dialog what does the Save above settings to option do Can
73. FreeOTFE FreeOTFE4PDA PC version v5 21 PDA version v5 21 By Sarah Dean sdean12 sdean12 org Last updated 7th February 2010 http www FreeOTFE org A free on the fly transparent disk encryption program for MS Windows 2000 XP Vista Windows 7 PCs both 32 and 64 bit and Windows Mobile 2003 2005 and Windows Mobile 6 and later PDAs Contents fintroduation 1 1 Features Download 3 Installation and Upgrading Spe vese 3 1 1 Automatic installation fo er ace a 3 2 1 Faster mounting 3 2 2 Altemative driver 4 Geting Started Guide 4 1finstallation Portable mode 4 2 UsingFreeOTFE 4 3 Creating a new volume 4 4 Mounting volumes 4 5 Dismounting volumes 4 6 Changing a volume s password 5 Advanced Topics Siete ae 5 1 1 Creating anew keyii 5 x 2 Mountin e te a eg Te using a keyfile Soccer 5 2 0 pec Nore for Windows Vista OF TGF BiN and Windows 7 By USE s 3 Creating Hidden Volumes 5 4 Wolume Creation Advanced ORTON oe Saar S 5 4 2 Salt 5 4 3 Drive Letter 5 4 4 CDE Loca 5 4 5 Padding 5 5 Password Entry Advanced Options SS drome sccaiy Dea 3 2fMount Options 5 5 3 Mountpoin sapine Cai 5 6 l installing New Driver _ 5 6 2 Modify Existing Driver 5 Engng Ts i 7 ea ie an Remote Media Token Smartcard Support 7 ong ithe 7 3 foken Eneryption Bite e DRNNDDD NH me o0 13 13 14 14 14 14 16 18 19 21 21 21 21 22 22 23 24 25 25 25 26 26 26 27 27 28
74. OCK Version PGP 8 1 not licensed for commercial use www pgp com mQGiBDekay4RBADuX QEqQ7W9POZ3V5x1IGj41p04 LB LhY2 ZMi0 Mt sMOg 6niJdT ctPBjyKCmm0LwleojZyLo7ArJ1Bkw4dswYbaULEDC nB4KEwOsJzfdceJ8j1063g KF Zy lqpuhAdEKr0am1UScp9109HndO TvW Tz2 6MGdpHZMSR6ppAI SyhSQCg eD e30cRdWgJRK30FPqJ8sZ4sD jOZUQOWE JcCS 9RCW3ciCbBdsdpeZt JTSwwiurj tQ vOZVmDxx rBuN2f 20BgeXGAlySaZBkO3FTEcctxN37v71h7LVa2Has RZyNL1 P35sTUgJW0 v6ZcevG4pTMhW4QWP QSUGKHVIVHekEDTy taeYb3kUVZBWIVnQXgJC 30c A 90ZHIMDyyezEDdElgAggilPatwIM61WdtX6r0fWF JGOKrrNCD3PS6FR30 EVryJdhgqUnmg jUYap50w2ITeAgcRronal 8rxaQUHpp2v213Tt 8b2Bs Fk2Z77AAzI xLgvQUOkhL8GN 3gtEO8ATIXVB6yswIWgmOF zCHSMH4zYJziprQgU2FyYWggRGVh biA8c2R1YW4xMkBzZGVhb jEyLm9yZz 6JAESEEBECAASFAKPGE80ECWMCAQAKCRAt 2N sS5614H1AKC32vVR75faqwiy9t pcaDkcsiWoylwCdF15khqKlwDDnscmFEeWM 73Phxoe5AgQ0EN6RrLhAIAPZCV7clfwgXcqk61qlC8wXo VMROU 2 8W65Szgg2gGn VqMU 6Y 9AVEPOB8bLO6mUrfdMZIZI AyDVWXpF 9Sh01D49V1 3HZSTz09jdvOmeFX klnN biudE F Ha8g8VHMGHOfM1m xxX5u 2RXscBqtNbno2gpXI 61Brwv0YAWCv1 9TjOWE5I280gtJ3kkOc2azNsOA1FHO98iLMcfFst jvbzySPAQ C1WxiNjrtVjLhd ONMO XwXVO0OjJHRhs3 JMALLUG zzhsSlAGBGNfISnCnLWhsQDGcgHKXrK1OzZlptr OApOmwJG0wg 9ZGRdOZ cfL2USyIZJrqrol7DVekyCzsAAgIH 2eFQW6w68YNeovi EvJtli4lorLsBIvbR8M3ql6ly75zdIScRCREtORSb2UNRXk fiqe7Fca gnmqUuBNU woo4NJAjyEz 7ADyUxcA uAU5 7anyqzexUhQUZ5s wEU7 7nYBFxOfNh S1sNF4yL8 Z5VIQVWUGIJLVLZs1Ap1RSGxXYMWJkO0kdBu2 j5wS0el6FrpgqoXzrJZpPUpiegUPOqY hg54Q0ddn9ksGO4LJUCLhI4X y54Pu9cWrcOt mKI
75. OTFE support Help I forgot my password I know it was something like Which is the best encryption algorithm to use How safe is FreeOTFE What happens if my volume file is corrupted or damaged in some way Will I lose all my data If someone steals my keyfile will they be able to decrypt by data and read it How do I know FreeOTFE is encrypting my data and with the encryption algorithm I choose When selecting a cypher to use why do the some cyphers appear multiple times Why are there duplicated cypher drivers Which of the duplicated drivers should I use Can FreeOTFE generate keyfiles which only allow read only access Can I use the same encrypted volumes on both my PC and PDA When creating a new volume how do I enable the sector IV options Is FreeOTFE vulnerable to watermarking attacks Is FreeOTFE vulnerable to Cold Boot Attacks on Encryption Keys aka DRAM attacks Does FreeOTFE have any form of password recovery Isn t FreeOTFE s keyfile functionality a security risk What happened to the NULL hash and NULL XOR cypher drivers How do I resize an encrypted volume How do I delete an encrypted volume How do I backup an encrypted volume Can I use any filename file extension for my FreeOTFE volume Does FreeOTFE support LVM2 Is it worth running file overwriter shredder programs to securely delete existing data stored on my encrypted drive What is the difference between the main FreeOTFE FreeOTFE
76. R O lt Typing Ismod will show you which modules are currently installed 9 9 2 Defaults If not overridden by the user dm crypt defaults to encrypting with Cypher AES Cypher keysize 256 bit User key processed with RIPEMD 160 not RIPEMD 160 Linux Twice with A Hash with A s if hash output is too short option selected IV generation 32 bit sector ID 9 9 3 Example 1 Volume Encrypted Using dm crypt s Default Encryption This example demonstrates use of a dm crypt volume using the dm crypt s default encryption system AES 128 with the user s password hashed with RIPEMD160 using the 32 bit sector IDs as encryption IVs Creating the volume file under Linux 62 dd if dev zero of volumes vol_default vol bs 1K count 100 losetup dev loop0 volumes vol_default vol echo password1234567890ABC cryptsetup create myMapper dev loop0 dmsetup 1s dmsetup table dmsetup status losetup dev loopl dev mapper myMapper mkdosfs dev loop1 mkdir test_mountpoint mount dev loopl test_mountpoint cp test_files SHORT_TEXT txt test_mountpoint cp test_files BINARY_ZEROS dat test_mountpoint cp test_files BINARY_ABC_RPTD dat test_mountpoint cp test_files BINARY_OO_FF_RPTD dat test_mountpoint umount test_mountpoint losetup d dev loopl cryptsetup remove myMapper losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE
77. ROM your settings can be stored together with FreeOTFE there is no need to configure FreeOTFE every time you use it on a different computer this would not be possible to do if the registry was used 2 When user settings are stored in a flat file as opposed to the registry security is increased It is trivial to overwrite a simple file if needed but removing registry entries completely is another matter Creating an encrypted partition disk will overwrite whatever data was stored on the partition disk you select Be careful An additional option is available to allow a program to be automatically executed O After a volume has been mounted Before a volume is dismounted After a volume is dismounted This functionality gives significantly more flexibility than the standard Windows autorun feature and allows automated integrity checking setup cleanup to be carried out For security reasons any file launched by the post mount and pre dismount options must reside on the encrypted volume a path relative to the root directory of the mounted volume should be specified in the options dialog e g MyFiles start bat For the post dismount option the absolute path to the file to be launched should be specified e g C volume_just_dismounted bat The pre dismount executable must terminate before the dismount will be carried out The pre dismount executable will not be launched in case of a forced emergency dismount
78. Rename this directory to reflect the new cypher s name 2 Modify my_build_sys bat Edit this file using a text editor to change O Allinstances of Blowfish to reflect new cypher s name O The files needed 3 Modify CYPHER_BLOWFISH veproj Rename this file to reflect the new cypher s name Edit this file using a text editor to change O Allinstances of Blowfish to reflect new cypher s name O What files are needed as per my_build_sys bat 4 Modify src sources Edit this file using a text editor to change O Allinstances of Blowfish to reflect new cypher s name O What files are needed as per my_build_sys bat In the sre directory rename all the Blowfish files to reflect the new cypher s name Start VC and load the FreeOTFE sln Visual Studio Solution Add the vcproj project file you modified above into the solution Within VC modify the new FreeOTFECypherXXX rc file to change all instances of Blowfish to reflect new cypher s name 9 Within VC modify FreeOTFECypherXXX h Change All instances of Blowfish to reflect new cypher name Add remove any DRIVER_CIPHER_TITLE_XXX entries as required All of the GUID values this is important The FreeOTFE GUI uses these values to differentiate between the different cypher implementations Set the definition of CYPHERS SUPPORTED to reflect the number of different cyphers the driver will provide i e the number of DRIVER_CIPHER_TITLE_X
79. SIV cypher used will be from the same family of cypher AES Blowfish Serpent etc but will use the keylength which matches the ESSIV hash output length As a result of this another option appears on the LUKS password entry dialog Base IV cypher on hash length If this is checked then when mounting an ESSIV volume the keylength of the cypher used for ESSIV generation will be that of the ESSIV hash If this is unchecked the ESSIV cypher used will have the same keylength as the main bulk encryption cypher used for securing the encrypted disk image Most users will want this option checked 9 6 2 FreeOTFE Supported LUKS Cyphers The following table lists compatibility with LUKS cyphers Compatibility Supported by FreeOTFE Supported by FreeOTFE Supported by FreeOTFE Supported by FreeOTFE Supported by FreeOTFE 9 6 3 FreeOTFE Supported LUKS Cypher modes The following table lists compatibility with LUKS cypher modes Compatibility Not supported by FreeOTFE ecb Note This is a pretty insecure mode the use of ECB is highly discouraged and FreeOTFE is unlikely to ever support this mode cbe plain Supported by FreeOTFE cbc essiv lt hash gt Supported by FreeOTFE xts plain Supported by FreeOTFE 9 6 4 FreeOTFE Supported LUKS hashes The following table lists compatibility with LUKS hashes 52 Hash Compatibility shal Supported by FreeOTFE sha256 Supported b
80. T 13 7 Portable Mode Tapas 7 148 13 8 Random Number Ee RNGs 21 22 148 149 149 149 149 149 150 153 153 154 155 155 156 157 158 159 159 160 161 162 163 163 170 173 173 174 174 174 175 175 175 175 176 177 183 183 183 185 185 185 186 1 Introduction FreeOTFE A free on the fly transparent disk encryption program for MS Windows 2000 XP Vista Windows 7 PCs both 32 and 64 bit and Windows Mobile 2003 2005 and Windows Mobile 6 and later PDAs Using this software you can create one or more virtual disks on your computer anything written to these disks is automatically and securely encrypted before being stored on your computers hard drive 1 1 Features Source code freely available Easy to use full wizard included for creating new volumes Data encrypted on your PC can be read written on your PDA and vice versa Powerful Supports numerous hash encryption algorithms and provides a greater level of flexibility than a number of other including many commercial OTFE systems Available in English Spanish German Italian French Czech Japanese Croatian Greek and Russian with support for other language translations Hash algorithms include MD5 SHA 512 RIPEMD 320 Tiger and many more Cyphers include AES 256 bit Twofish 256 bit Blowfish 448 bit Serpent 256 bit and many more Cypher modes supported include XTS LRW and CBC including XTS AES 128
81. This should start the driver selected 4 Change the driver s startup option to At system startup and click Update 7 Click the Close button These steps will install and setup a FreeOTFE in a minimalist installation With these steps complete you may now use FreeOTFE to create and mount FreeOTFE and Linux encrypted volumes The drivers installed are configured such that they do not automatically startup when your system boots Once you are happy that FreeOTFE is stable enough you may return to the driver management dialog select each driver in turn and set them to start automatically at system startup Note In order to use FreeOTFE you musthave the following drivers installed and running as the bare minimum for FreeOTFE to operate correctly 1 The main FreeOTFE driver 2 At least one hash driver FreeOTFEHash 3 At least one cypher driver FreeOTFECypher A number of the cyphers e g RC6 and Twofish have multiple drivers these reflect different implementations e g FreeOTFE comes with three Twofish implementations one based on the libtomcrypt library one based on the optimised reference implementation and one based on Brian Gladman s implementation Each of these drivers provides pretty much the same functionality it s just the implementation that differs Were multiple drivers are provided for the same cypher you only need to install one of them You can mix drivers based on different implementations e g
82. To prevent the prompt appearing please uninstall one of the offending drivers Q Do I need Administrator privileges to use FreeOTFE on my computer A No Although Administrator privileges are needed to install the FreeOTFE drivers or start stop portable mode To allow standard non Administrator users to use FreeOTFE please install the FreeOTFE drivers by following the instructions in the Installation and Upgrading section After which any user will be free to use FreeOTFE e g to create mount dismount and use encrypted volumes To access an encrypted volume on a PC which doesn t have FreeOTFE installed and on which you don t have Administrator privileges please use FreeOTFE Explorer Q Why do I need Administrator rights to install FreeOTFE A This is probably the most common FAQ with respect to OTFE systems In order for most if not all OTFE systems to operate they require the use of kernel mode drivers to carry out drive emulation A kernel mode driver is special piece of software which operates at a very low level within your computer s operating system As such it can do pretty much anything to your system including carrying out privileged actions that normal users are not allowed to do e g formatting your HDD Because of this MS Windows only allows users with Administrator rights to install such drivers NOTE Administrator rights are not required in order to use FreeOTFE once installed To acce
83. Token Smartcard Support section for more information on setting up and using PKCS 11 tokens 13 9 Building the Software FreeOTFE FreeOTFE4PDA FreeOTFE Explorer come in a number parts 149 FreeOTFE 1 A front end GUI written in Delphi 2 A number of kernel drivers written in C FreeOTFE4PDA 1 A front end GUI written in C 2 Anumber of drivers written in C FreeOTFE Explorer 1 A front end GUI written in Delphi 2 The same drivers as FreeOTFE4PDA but built for Win32 A number of command line decryption utilities also written in C 13 9 1 FreeOTFE 13 9 1 1 Building the GUI This is a description for Delphi newbies of the basic steps involved in compiling the FreeOTFE GUI To build the GUI the following software is required Delphi CodeGear Delphi 2007 or later though Delphi 2006 should just as well Delphi v5 v7 can probably be used with minimal changes though wouldn t look as nice under Windows Vista The SDeanComponents package v2 00 00 or later Optional GNU gettext for Delphi dxgettext available free from http dybdahl dk dxgettext This package adds support for language translations The binary release of this software was built with CodeGear Delphi 2007 1 With each of the packages in the SDeanComponents archive 1 Build each package 2 Install each package 3 Ensure that the correct path to each package is added to your Delphi environment Tools Environment Options Library tab
84. TomCrypt 128 CBC LRW XTS LibTomCrypt 128 CBC LRW XTS LibTomCrypt 128 CBC LRW XTS LibTomCrypt 128 CBC XTS Dr Brian R Gladman 128 CBC XTS Dr Brian R Gladman 128 CBC XTS Dr Brian R Gladman 128 CBC XTS Dr Brian R Gladman 128 CBC XTS Dr Brian R Gladman 128 CBC XTS Dr Brian R Gladman Hi fn and Counterpane Systems x86 systems only Hi fn and Counterpane Systems x86 systems only CBC Hi fn and Counterpane Systems x86 systems only CBC LRW XTS LibTomCrypt CBC LRW XTS LibTomCrypt CBC LRW XTS LibTomCrypt Hash algorithms included Hash Length in bits Block Length in bits Source Library MD2 128 128 LibTomCrypt MD4 128 512 LibTomCrypt MD5 128 512 LibTomCrypt Null variable variable n a RIPEMD 128 128 512 LibTomCrypt RIPEMD 160 160 512 LibTomCrypt RIPEMD 160 Linux Twice with A 320 512 LibTomCrypt RIPEMD 256 256 512 LibTomCrypt RIPEMD 320 320 512 LibTomCrypt SHA 1 160 512 LibTomCrypt SHA 224 224 512 LibTomCrypt SHA 256 256 512 LibTomCrypt SHA 384 384 1024 LibTomCrypt SHA 512 512 1024 LibTomCrypt Tiger 192 512 LibTomCrypt Whirlpool
85. Why does FreeOTFE4PDA s version numbering skip from v0 55 to v2 00 what happened to v1 00 A FreeOTFE4PDA s version number was incremented to v2 00 in order to match the PC version of FreeOTFE with which FreeOTFE4PDA shares a fair amount of common code A specific v1 00 was never released although there were a fair number of non public versions released between v0 55 and v2 00 to various people to help with testing and confirm compatibility Q Why does FreeOTFE4PDA s version numbering skip from v3 76 to v5 00 what happened to v4 00 A FreeOTFE4PDA s version number was incremented to v5 00 in order to better reflect that its level of functionality was on a par with the PC version with the same version number after support for encrypted Linux volumes and language translations were added in v5 00 117 A specific v4 00 was never released although there were a fair number of non public versions released between v3 76 and v5 00 to various people to help with testing and confirm compatibility Q When I use the open dialog to select my volume file Keyfile it doesn t list the file Pm trying to specify even when I select All files where is it A The standard Windows Mobile open file dialog is a little odd this isn t just restricted to FreeOTFE Although FreeOTFE allows you the freedom to use any filename you wish only files which have a filename extension i e the volume s filename has a full stop
86. XxX definitions you have 10 Within VC modify FreeOTFECypherXXX c Change O The cipher descriptions returned O The initialization and encrypt decrypt routines to check for and use the correct cypher Oo aD 156 11 Modify clean bat in the top level src directory to clean up any object garbage etc files that are created when your driver is built 12 You should now be able to build your new cypher driver which may then be installed as per any other cypher or hash driver 13 10 1 Hash Length Blocksize When your hash driver is asked for details of the hash algorithms it provides the hash length returned for each hash algorithm must be one of the following Validity Meaning Comments Hashes which return zero length hash values cannot be used with FreeOTFE volumes FreeOTFE volumes use PKCS 5 PBKDF2 HMAC which requires that the length of hash values returned is greater than zero Hash values returned are 0 bits long Hash values returned are of Hashes which return variable length hash values variable length e g the cannot be used with FreeOTFE volumes NULL hash which returns FreeOTFE volumes use PKCS 5 PBKDF2 its input as the generated hash HMAC which requires that the length of the value hash values used is fixed Hash values returned have a fixed defined length e g SHA 512 s hash length is 512 bits Must be a multiple of 8 When your hash driver is asked for d
87. _mountpoint the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume file 3 Key tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Change the seed to seedvalue Select the SHA 512 512 1024 hash Make sure that the Hash with A s if hash output is too short is not checked Leave iteration count at 0 4 Encryption tab Select the AES CBC 256 128 cypher Select the 32 bits sector IV IV generation method Set Sector zero location to Start of host file 5 File options tab Leave offset at 0 Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button 59 9 8 9 Example 7 Volume Encrypted Using 256 bit AES and Offset This example demonstrates use of a Linux AES256 volume with the encrypted volume beginning at an offset of 2560 bytes into the volume file Creating the volume file under Linux dd if dev zero of vol_aes256_2560 bs 1k count 1024 losetup e AES256 o 2560 dev loopO vol_aes256_2560 Enter password password1234567890ABC mkdosfs dev loop0 mkdir test_mountpoint mount dev loop0 test_mountpoint echo This is a text test file gt test_mountpoint SHORT_TEXT txt umount dev loop0 losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume f
88. a trivial side effect The words Test Mode are shown in the four corners of the Desktop wallpaper after rebooting Although only a cosmetic issue the words Test Mode may be removed from your background by using one the following methods e Remove and Erase Desktop Evaluation Copy Test Mode or Safe Mode Watermark i o Get Rid OF and Remove Evaluation Copy Watermark in Visia After Installating SP1 e Remove and Disable Windows Vista Evaluation Watermark from Desktop Alternatively using Windows DreamScene which allows videos to be shown as an animated desktop wallpaper instead of a static image will prevent the Test Mode watermark being shown DreamScene is intended for use with Ultimate edition of Windows Vista Windows 7 though other animated desktop solutions are available for users with other editions e g Home or Business 3 1 3 5 Method 4 lt F8 gt while booting Instructions 1 Reboot the PC 2 At the start of the boot sequence press lt F8 gt 3 When prompted select the Disable Driver Signature Enforcement option and press lt ENTER gt Note This method is not persistent and its effect will cease the next time the PC is rebooted unless this procedure is carried out again while rebooting However the ReadyDriver Plus method described below may be used to carry it out automatically 3 1 3 6 Method 5 ReadyDriver Plus ReadyDriver Plus is a piece of boot loader software which automatically
89. a volume s password To change a volume s password or a keyfile s password select the Tools Change volume keyfile password details menuitem or Tools Change password details on the PDA version to display the change password wizard which will guide you through the process in a series of simple steps Note that volumes must be dismounted first before they can be modified in this way You may also change certain volume keyfile details via this wizard for example the default drive letter which the volume will normally be mounted as Advanced users may also change more technical details such as the length of salt used in encrypting the volume s CDB keyfile In common with most disk encryption systems FreeOTFE uses an encrypted master key system to secure volumes Every FreeOTFE volume has its own master encryption key which is generated when the volume is created This master key is used to carry out the actual encryption decryption process used to secure data stored within the volume A volume s master encryption key is in turn encrypted with the PBKDF2 processed user s password As a consequence FreeOTFE doesn t need to decrypt and re encrypt the entire volume to change the user s password only the encrypted master encryption key This makes changing a volume keyfile s password an extremely quick and risk free operation when compared to a complete volume re encryption 20 5
90. all in C WINDDK 3790 Include the Illustrative Driver Samples Include the Input Samples Include the Storage Samples Include the Virtual Device Driver Samples Include the WDM Samples Build Environment Windows Driver Development Kit AMD64 Additional Build Tools Build Environment Windows Server 2003 AMD64 Libraries Build Environment Windows XP Headers 151 Build Environment Windows XP x86 Libraries Build Environment Windows XP IA86 Libraries O Needed if the build BAT files see later use chk WXP if that s skipped it ll default to WNET windows NET Build Environment Windows 2000 Headers Build Environment Windows 2000 Build Environment O Needed if the build BAT files see later use chk lt something gt if that s skipped it ll default to WNET windows net 13 9 1 2 1 2 FreeOTFE Build Configuration 1 Edit setup_env_common bat located under src drivers Common bin and ensure that the following variables are set appropriately Variable Description Default value Build type flag set to 1 for debug build or O for FREEOTFE_DEBUG release Target OS to build for e g WXP W2K WNET note that W2K builds will not operate correctly under Windows XP e g when formatting a volume FREEOTFE_TARGET The drive on which you have stored the FreeOTFE source PROJECT_DRIVE The full drive and path where the drivers lt see file gt directory is located PROJECT_DIR MSSDK_DIR The direct
91. also when mounting a volume to prevent the password entry dialog showing saltlength lt saltlength gt The length of the salt in bits The volume filename partition to be used When using a volume file this should be set to the full path and filename of a volume file Partitions should be specified in the form Device HarddiskX PartitionY volume lt volume gt where X is 0 based while Y starts from 1 to indicate a particular partition or 0 to indicate the entire disk Important If the volume filename has any spaces in it then it should be enclosed in double quotes Note Under Windows Vista the install and uninstall options require FreeOTFE exe to be explicitly runas an account with administrator privileges if not being executed from a process which has already been escalated see examples below The portable will automatically escalate to administrator privileges if required 8 1 4 Exit Codes When run at the command line FreeOTFE will terminate with one of the following exit codes Meaning Success Invalid unrecognised command line Unable to connect to FreeOTFE driver check driver is installed or portable mode is started Jnable to mount volume Jnable to dismount volume Jnable to start portable mode Jnable to stop portable mode The requested operation requires administrative privileges Other error 8 1 5 Examples Mounting a FreeOTF
92. altlength and keyiterations command line options Added additional check on saltlength when creating new volumes Fixed trivial bug introduced in v4 70 causing CDB dumps to report the hash driver used twice instead of the hash driver and cypher driver used Fixed bug introduced in v4 70 which prevented per volume IVs from being passed to the backend driver Only affects CBC based i e very old volumes which use per volume IVs v4 70 4th April 2009 O oo0o0o0 O O O Spanish translation added Added option to volume creation wizard to mount new volumes after creating them Added support for Windows 7 Added autodetect functionality for PKCS 11 libraries GUI and driver code refactored to allow common code to be shared between FreeOTFE and FreeOTFE Explorer Fixed uninstaller bug which prevented it from cleaning out installation subdirectories Fixed bug causing GUI to go into a tight loop when switching to a language for which the translation required certain specific controls to be resized Fixed bug which could potentially cause FreeOTFE to crash on dismount v4 60 19th February 2009 O O O French translation added Corrected fault causing exit status 102 to be returned when mounting volume from the command line with silent specified Various cosmetic improvements mainly relating to translations v4 50 1st January 2009 O O O Italian translation added Added option to prevent message showing on s
93. and can mount it on my PC but why does it keep asking if I want to format it A When you created your volume on your PDA your PDA fully formatted the volume as though it was a new device not just a partition on a device In order for a volume to be mounted and used correctly on both a PDA and PC it should be created and formatted using a PC as a FAT volume and subject to the maximum volume size your PDA can support see FAQ on volume sizes This will ensure it can be read on all systems Q I created a volume on my PC and can mount it successfully on my PDA but can t see any of my files A The chances are that you formatted your volume on your PC using NTFS and your PDA doesn t support this filesystem Volumes which are to be used on a PDA should normally be formatted as FAT or FAT32 this should be carried out on a PC not a PDA see related FAQ Please note also that FAT32 can only support volumes up to 4GB less one byte Q How can I speed FreeOTFE up when mounting my volumes A For security reasons FreeOTFE doesn t store any information relating to which hash cypher combination was used to encrypt a FreeOTFE volume As a result FreeOTFE is forced to cycle through all of its possible hash cypher combinations in order to determine which one to use Reducing the number of combinations it has to check can significantly reduce the time this takes To reduce the number of combinations without making any diff
94. apper losetup dev loopl dev mapper myMapper mkdosfs dev loop1 mkdir test_mountpoint mount dev loopl test_mountpoint cp test_files SHORT_TEXT txt cp test_files BINARY_ZEROS dat cp test_files BINARY_ABC_RPTD dat cp test_files BINARY_0OO_FF_RPTD dat umount test_mountpoint losetup d dev loopl cryptsetup luks luksClose myMapper losetup d dev loop0 rm rf test_mountpoint test_mountpoint test_mountpoint test_mountpoint test_mountpoint 72 Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the losetup volume file 3 In the dialog shown enter password1234567890ABC as the key and set any of the options wanted 4 Click the OK button 9 10 5 Example 3 Volume Encrypted Using 128 bit Twofish This example demonstrates use of a LUKS Twofish 128 volume Creating the volume file under Linux dd if dev zero of volumes vol_twofish vol bs 1M count 1 losetup dev loop0 volumes vol_twofish vol echo password1234567890ABC cryptsetup luks c twofish luksFormat dev loop0 cryptsetup luks luksDump dev loop0 echo password1234567890ABC cryptsetup luks luksOpen dev loop0 myMapper dmsetup 1s dmsetup table dmsetup status cryptsetup luks status myMapper losetup dev loopl dev mapper myMapper cat test_files 2MB_Z dat gt dev loopl cat test_files 2MB_0x00 dat gt dev loopl mkdosfs dev loop1l mkdir test_mountpoint mount dev loopl t
95. at this time A If you see this error message you have correctly entered all details to allow FreeOTFE4PDA to mount your encrypted volume however Windows Mobile has failed to activate the FreeOTFE4PDA virtual storage device This error appears to be related to the wireless functions mobile phone wifi bluetooth of these particular devices turning off wireless functionality and possibly carrying out a soft reset of the device can resolve this issue This issue has been reported to affect the following devices T Mobile Vario WM v5 1 195 Build 14847 2 0 0 MDA Vario II HTC TyTn WM v5 1 195 Build 14955 2 3 0 O2 Exec QTEK 9000 WM v5 1 195 Build 1487 2 0 0 Fujitsu Siemens Loox T830 WM v5 1 195 A version of FreeOTFE4PDA which should resolve this issue is currently under development and will appear in a later release Q Which PDAs will FreeOTFE4PDA work with A FreeOTFE4PDA has been tested with various Windows Mobile 2003 2005 and Windows Mobile 6 devices and should work with all Windows Mobile 2003 and later PDAs Smartphones which do not have a touchscreen may not display FreeOTFE4PDA s interface correctly though Smartphones which do have a touchscreen can use FreeOTFE4PDA Q What does the Support WM 5 0 soft keys option do A Under Windows Mobile 5 0 and later you have the option of displaying FreeOTFE s menus and Wizard navigation using the new style two item softkey menus This is the Microsoft standard fo
96. at you make absolutely sure you have selected the correct disk partition to be used when creating a new partition based volume 5 2 1 1 Backing up The volume creation process will overwrite the first 512 bytes of the selected partition or start of the disk if using the entire disk You might wish to use the FreeOTFE s backup functionality Tools Critical data block Backup to back up this part of the disk prior to creating a partition disk based volume which will allow you to revert the changes FreeOTFE makes to your partition disk should you realise that you ve selected the wrong one Note Such a backup will be of limited use after the volume created has been mounted and formatted since formatting will carry out further overwrites to the partition disk Ideally you should backup your entire system before creating encrypted partitions just to be on the safe side though this is unlikely to be particularly practical for many users 5 2 1 2 Create New Volumes as an Administrator The partition display shown by FreeOTFE will give more information about the partitions on a disk e g drive letters allocated size of partitions proportional display when used by a user with administrative privileges A user with normal privileges will be shown less information due to their restricted access rights 22 FreeOTFE Volume Creation Wizard Please select the partition you wish to create the new volume on and whether you wou
97. ata 5 File options tab Leave offset at 0 Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button 9 9 9 Example 7 Volume Encrypted Using 448 bit Blowfish MD5 Password Hashing and SHA 256 ESSIV This example demonstrates use of a dm crypt Blowfish 448 volume with the user s password processed with MD5 and ESSIV using SHA 256 Note that although the main cypher is Blowfish 448 Blowfish 256 is used as the IV cypher as the IV hash outputs 256 bytes Creating the volume file under Linux dd if dev zero of volumes vol_blowfish_448_essivsha256_md5 vol bs 1K count 100 losetup dev loop0 volumes vol_blowfish_448_essivsha256_md5 vol echo password1234567890ABC cryptsetup c blowfish cbc essiv sha256 s 448 h md5 create myMapper dev loop0 dmsetup ls dmsetup table dmsetup status losetup dev loop1l dev mapper myMapper mkdosfs dev loop1 mkdir test_mountpoint mount dev loopl test_mountpoint cp test_files SHORT_TEXT txt test_mountpoint cp test_files BINARY_ZEROS dat test_mountpoint cp test_files BINARY_ABC_RPTD dat test_mountpoint cp test_files BINARY_OO_FF_RPTD dat test_mountpoint umount test_mountpoint 68 losetup d dev loop1 cryptsetup remove myMapper losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume file 3 Key tab
98. ation and Upgrading from a Previous Version section When reporting a fault with FreeOTFE please include as much detail as possible preferably including as much of the following as possible Note Not all of the following may apply 1 What OS you re running under 2 Any service packs which have been applied to your OS 3 The FreeOTFE executable version See the Help About dialog 4 The main FreeOTFE driver version See the Help About dialog 5 Details of how the volume in question was created e g the summary shown on the last stage of creating a FreeOTFE volume 6 The size of any volume file partition involved If using a volume file the filesystem used on the drive the volume file is stored on e g NTFS FAT FAT32 8 The filesystem the volume is formatted as e g NTFS FAT FAT32 9 A copy of the CDB dump taken from any volume file involved See Tools Critical Data Block Dump to human readable file 10 If a keyfile is being used a copy of the keyfile and password used 11 A small test volume e g IMB which can replicate the problem found Note Please do not email volume files unless asked to An FTP site is available for uploading these Some of the items listed above may include potentially sensitive data In which case feel free to omit that information or better still create a simple test case which replicates the problem but doesn t include any such data Additionally if y
99. ault settings to display system tray icon by default Improved support for dismounting drives nested within each other Added noexit command line option Added password and silent command line parameters for mounting Linux volumes Added greater emphasis on the fact that when overwriting a partition with encrypted data whatever was previously stored on that partition will be overwritten Yes some people did email about this Prevent FreeOTFE from exiting when the wrong password is entered Various cosmetic improvements v4 30 27th October 2008 O O O O O O O oo0o0o0o0 y O0O0000 0 Added functionality to support language translations Added password and silent command line parameters for mounting FreeOTFE volumes Added additional option to overwrite an entire mounted volume as well as its free space Added support for optionally substituting the mounted drive letter as a parameter passed to any post mount and pre post dismount autorun commands configured Added support for post mount and pre dismount autorun commands with spaces in their paths Added option to display passwords as they re entered Driver development environment changed to Microsoft Visual Studio 2008 with WDK for Server 2008 v6001 18001 although older versions can probably still be used Corrected intermittant fault causing FreeOTFE to crash on mounting some volumes Corrected fault preventing hidden volumes being created on host vo
100. below 23 1 Automatic Uninstall If installed via the installation wizard FreeOTFE may be uninstalled by either 1 Using the Add and Remove Programs control panel applet 2 Running uninstall exe found in the directory FreeOTFE was installed in 23 2 Manual Uninstall Launch FreeOTFE exe Unmount all mounted volumes Select File Drivers Select each of the drivers you have installed and click Uninstall Repeat this until all drivers have been uninstalled If you encounter errors in this step don t worry just continue uninstalling your other remaining drivers 5 Exit FreeOTFE Reboot your computer 7 You shouldn t need to but if you encountered any errors while uninstalling the drivers 1 Run regedit exe and remove all registry keys under HKEY_LOCAL_MACHINE S YSTEM CurrentControlSet Services that have FreeOTFE in their name 2 Delete all files beginning FreeOTFE from your lt windows gt system32 drivers directory you may need to reboot your computer again before you can do this 3 If you deleted any registry entries or files reboot your computer again 8 Finally delete FreeOTFE exe and any shortcuts you may have created BwWN Re On 185 24 Appendix H Contact Details Please send any comments feedback etc to sdeanl2 sdean12 org If you would like to send PGP encrypted email feel free to use the following public key block download RAS BEGIN PGP PUBLIC KEY BL
101. block CDB at the start of it and the byte was written to the first 512 bytes of the volume file where the CDB is located then the volume would be unmountable unless you had made a backup of this area of your volume or created a keyfile in which case you could restore from your backup mount from your keyfile and continue as if nothing had happened 2 If the volume file was created without a critical data block or the byte was written to any other part of your volume file then the sector that corresponded to the location that the byte was written to would be corrupted from approximately the point the byte was written to the end of that sector a maximum of 512 bytes To protect against 1 FreeOTFE included functionality to backup a volume s CDB see Tools Critical data block Backup and to create keyfiles see Tools Create keyfile Should case 2 occur the damage to your volume would be minimal up to a maximum of 512 bytes and restricted to the sector that was corrupted 93 Q If someone steals my keyfile will they be able to decrypt my data and read it A No not unless they have the keyfile s password as well Keyfiles are encrypted Without the password used to encrypt it a keyfile is pretty much just a useless block of random data Q How do I know FreeOTFE is encrypting my data and with the encryption algorithm I choose A To verify that encryption decryption is taking place for Linux
102. build up a FreeOTFE CDB keyfile 1 Obtain all the information which will be stored within the volume s Volume details block 2 Derive the critical data key by processing the user s password and salt with PKCS 5 PBKDF2 using HMAC with the user s choice of hash algorithm The derived key should be ks bits long i e the cypher s keysize If ks is undefined then 512 bits will be used Note In this case the keysize used for encrypting decrypting the encrypted partition image must be specified by the user The keysize for the critical data block is fixed at 512 bits if ks is undefined in order to simplify the mount volume dialog and to reduce the potential for user confusion as most cyphers have a fixed ks and asking users for this information may cause them to think this is more information they have to memorise which it wouldn t be 3 Create the plaintext version of the Volume details block in memory including padding the end with random data as appropriate 4 Calculate the check MAC using HMAC together with the derived key and user s choice of hash algorithm 5 Truncate the MAC to 512 bits if it is longer or right pad to 512 bits with random data to if less 6 Prepend the check MAC and any random data appended to it onto the beginning of the volume details block to form a plaintext version of the Encrypted block 7 Encrypt the plaintext Encrypted block using a null IV and the critical data key 8 Prepend the salt b
103. c issues under this OS Added option to allow mounted volumes to be visible to all logged on users or just the current user Added option to associate vol files with FreeOTFE in line with the PDA version and defaulted open save dialog filters Note that you are still free to use any filename with any filename extension Added ability to store FreeOTFE settings in different places or not at all if required Updated to automatically prompt user if they want to start portable mode if the main FreeOTFE driver isn t installed running Added indicator to show portable mode activating Added ability to combine random number generators RNGs when generating random data for new volumes changing passwords Added option to start FreeOTFE in portable mode without prompting if no installed drivers 166 O are found Added option to suppress prompting for volume type when volume files are drag n dropped onto FreeOTFE Added additional prompt when creating new volumes to make it clearer when the minimum amount of information required had been entered Added option to allow user to specify where their settings should be stored if they are to be saved Added extra support for odd LUKS volumes which don t use the same cypher keylength for IV generation as encrypting data e g volumes which use Blowfish 448 for data encryption and cbc essiv sha256 actually use Blowfish 256 for their ESSIV IVs this is now supported Added detection of
104. called SD Card where your SD storage card appears under 5 6 Driver Control j A This section applies to the PC version of FreeOTFE only The driver control dialog may be accessed by selecting File Drivers From here you may see all drivers installed and their current state A summary of all available hash and cypher algorithms can be found by selecting Help List hashes Help List cyphers 29 FreeOTFE Driver Control Install new driver To install a new hash or cypher driver please click Install Modify existing driver Existing drivers fv 1dFreeO TFE w Driver startup gt FreeQTFECypherAES_Gladman Manual v gt FreeQTFECypherAES Itc gt FreeQTFECypherBlowfish Ch dri R gt FreeOTFECypherCASTS et pe Se gt FreeQTFECypherCAST6_Gladman gt FreeQTFECypherDES Se gt FreeQ TFECypherMARS_ Gladman gt FreeOQTFECypherNull srw gt FreeOTFECypherRC6_Gladman PII gt FreeQTFECypherRCB_ltc gt FreeOTFECypherSerpent_Gladman v Driver control dialog 5 6 1 Installing New Drivers FreeOTFE drivers may be installed by clicking Install and selecting the driver file to be installed FreeOTFE will then install the driver selected adding it to the list of installed drivers start it and sets it to automatically start up whenever the PC boots up More than one driver can be installed at the same time by selecting holding down lt SHIFT g
105. capital letter A is prepended to the user s password and a new hash is generated 5 This third hash is appended to the previous hashes 6 If the total hash output contains fewer bits than the cypher s keysize another capital letter A is prepended to the user s password and a new hash is generated 7 and so on until the required keylength is reached i e This is the same as Cryptoloop uses for its RIPEMD 160 hashing but is extended to produce a key of arbitrary length by adding multiple A characters to the password and hashing until a key of the required length is obtained FreeOTFE supports this form of key processing which can be invoked by selecting the option Hash with A s if hash output is too short on the Linux mount dialog Note that under linux the actual encryption decryption key can be shown in its hex representation by running dmsetup table For example if the volume s password is password1234567890ABC then If AES 256 bit key is used for encryption decryption and the user s password is processed with RIPEMD 160 the actual encryption decryption key will be FAFE5 6C3BAB4CD21 6BA02474AC157EA555FA5711D539285C28A6D8122D94 64EE This is made up as follows 7 The first 160 bits are the RIPEMD 160 hash of E56C3BAB4CD216BA02474AC157EA555FA5711 password 1234567890ABC The remaining bits are the first 96 bits taken from D539285C28A6D8122D9464EE0AA3C4811DE
106. carries out the lt F8 gt while booting method of enabling driver loading Instructions 1 Download a copy of ReadyDriver Plus v1 1 or later from Citadel Industries 2 Install the software 3 Reboot the PC 3 1 3 7 Method 6 EasyBCD Instructions Download a copy of EasyBCD v1 7 or later tested with v1 7 2 from NeoSmart Technologies Install the software Run EasyBCD Click the Advanced Options button Check the Allow unsigned driver installation on Vista 64 Bit Edition checkbox Click Apply Settings Reboot the PC NDMP WN Ke Although NeoSmart Technologies implemented some functionality to allow the use of unsigned drivers under Windows Vista x64 testing shows this appears limited to setting DDISABLE_INTEGRITY_CHECKS see method above via a pretty GUI despite their change log claims to Allow 100 of unsigned drivers to run on Vista 64 Bit Edition Support for this functionality was effectively dropped in August 2008 Because of this it is recommended that Method 2 DDISABLE_ INTEGRITY _CHECKS be employed rather than EasyBCD since it offers no significant advantages 3 1 3 8 Method 7 Signing with a Microsoft certificate This method requires signing the FreeOTFE drivers with a Microsoft certificate as opposed to the self certified signature currently used in the release There are currently two ways of signing the FreeOTFE drivers 1 Find someone with a digital certificate and as
107. create a file of the appropriate size and is the equivalent of the Linux command dd if dev zero of vol_none bs 1M count x Where x is the size of the volume in MB This step is unnecessary in case of using an existing partition on your HDD and is only required in order to create the file which is to store the encrypted data 3 Select File Linux volume Mount 4 Enter the appropriate parameters into the mount dialog See the Linux Examples section in the documentation for example configurations the choices you make here must reflect those options that are supported by the version of Linux you wish to subsequently use the volume with 5 Click the OK button This will mount the volume using the encryption system s specified and is analogous to executing the Linux commands losetup dev loop0 lt volume file gt lt various options gt mkdir mountpointmount dev loop0 mountpoint At this point a new drive should appear although at this stage it is unformatted and you will be given an error if you attempt to access it e g using Windows Explorer 6 Select the new drive 7 Select Tools Format You will be shown the standard MS Windows format dialog It is suggested that you select either the FAT or FAT32 filesystem 47 8 Click OK button to format the volume This is analogous to the Linux command mkdosfs dev loop0 Your volume file is now fully ready for use although for security reasons it is highl
108. cribes the high level layout of a FreeOTFE CDB Critical data block Password salt Encrypted block Volume details block Random Check CDB RA MAC padding Volume partition 3 format flags ID age Color key Random Requested Volume Sector IV Random P adding Master Voume eneration paddin H key IV 8 pareng Encryption used Red items are not encrypted Blue items are encrypted with the user s chosen cypher together with a critical data key generated using PKCS 5 PBKDF2 with HMAC PRP together with the user s password salt and chosen hash algorithm Seem intimidating Read on and all will become clear When broken down into its component parts the CDB structure is reasonably straightforward to understand Note Throughout this document the following definitions apply 137 Variable Definition Critical Data Length in bits EDL This is defined as 4096 bits Maximum MAC Length in bits MME This is defined as 512 bits Salt length in bits This is the user specified salt length as specified by the user when the CDB is created Cypher Block Size in bits The block size of the cypher used to encrypt the volume Cypher Key Size in bits The key size of the cypher used to encrypt the volume If the cypher accepts variable length keysizes this is set to a user specified value up to a maximum of 512 MAC length in bits This is the l
109. curity token smartcard as an option to provide additional security they are not necessary to use FreeOTFE Q What is the difference between PKCS 11 Cryptoki and tokens A PKCS 11 and Cryptoki are the same thing an API for accessing security tokens smartcards Token is a generic term to refer to a security token or smartcard Q Does FreeOTFE encrypt my entire encrypted volume using my PKCS 11 token A No just the volume s CDB keyfile Encrypting the entire volume would incur significant performance penalties due to the relatively low power of security tokens when compared to a PC and need to transfer data twice over the USB connection once to sending the encrypted plaintext data and again to receive the plaintext cyphertext Q I ve inserted my PKCS 11 Cryptoki token but why is the PKCS 11 token management menuitem disabled A Please ensure that you have configured FreeOTFE to use your token via the PKCS 11 tab on the Options dialog View Options See the section on Security Token Smartcard Support for further details Q How do I change the password on a volume keyfile which is secured with a PKCS 11 secret key A To change the password on a volume keyfile which is secured with a PKCS 11 secret key 1 Decrypt the volume s CDB keyfile using the token s secret key 1 Go to Tools PKCS 11 token management 2 Select the Secret keys tab 3 Select the appropriate secret key 4 Clic
110. d the Check hash onto the Volume details block to build the plaintext version of the Encrypted block Append the salt onto the user s password Hash the salted password with the user s chosen hash algorithm 10 If the hash generated has less than ks bits it should be right padded with zero bits until it is ks bits long If the hash generated has more than ks bits it should be truncated to the first ks bits The truncated padded hash will be used as the critical data key Encrypt the plaintext Encrypted block with the user s selection of cypher an IV of bs zeroed bits and the critical data key Prepend the salt onto the cyphertext version of the Encrypted block Append Random padding 1 to the Encrypted block in order to pad it out to 4096 bits 512 bytes and form the complete Critical data block Write the Critical data block to the volume file beginning from the start of the file for normal FreeOTFE volumes or from the user s offset in the case of a hidden volume 13 2 1 9 Mounting FreeOTFE Volumes IMPORTANT Versions of FreeOTFE v00 00 0x that used this CDB format had an implementation fault that caused the Volume Details Block to be incorrectly parsed when it was read in It incorrectly used the 32 bits starting from offset byte 10 within the Volume Details Block i e data storing the part of the encrypted partition image length as the VolumeFlags This has been compensated for in later v
111. den volume 6 If the volume you wish to create a hidden volume in is mounted dismount it Start the volume creation wizard as normal select File New from the main menu When prompted to select between creating a file or partition based volume select File or Partition depending on whether the host volume you wish to use is file or partition based When prompted for the filename partition to create your hidden volume on select the host file partition you wish to create the hidden volume inside The next step in the wizard will prompt you to enter an offset The offset is the number of bytes from the start of the host volume where you wish the hidden volume to begin Make sure that the offset you specify is large enough such that it does not overwrite any of the system areas of that host volume e g the FAT or files already written to it Continue with the volume creation wizard as normal To mount your hidden volume proceed as if mounting the host volume but when prompted to enter your password click the Advanced button and enter the offset See the section on advanced password entry options Make sure you remember the value you enter for the offset value For security reasons FreeOTFE doesn t store this information anywhere and so you will have to enter the same offset into the password entry dialog every time you wish to mount your hidden volume SECURITY More than one hidden volume can be stored within the
112. ding data Required to pad out the check MAC to padding 3 a predetermined number of bits Volume This stores the details of how to encrypt decrypt the encrypted details partition Total size 13 2 3 4 Breakdown Volume details block layout CDB oe Master Requested Volume Sector IV Random Volume partition Master Volume format flags key ke Iv generation padding ID 8 length y Finally we reach the details that the critical data block was designed to protect All of the items within this block have bit order MSB first Size in bits Description Item name This is a version ID which identifies the layout of the remainder of the volume details block CDB format g When this layout format is used this will always be set to 3 ID Later volume file layouts may have different items in this section or the layout may change in which case a different version ID will be used here 139 Volume flags Bitmap flagging various items Bit Description 0 unused 1 Sector ID zero is at the start of the file 0 Sector ID zero is at the start of the encrypted data 1 Sector ID zero is at the start of the host volume file partition 2 unused 3 unused 4 Volume file timestamps normal operation 0 On dismount volume file timestamps will be reset to the values they were when mounted 1 On dismount volume file timestamps will be left as is i e will indicate the date tim
113. e primarily intended to allow verification of the implementations and increase confidence that they re actually doing what it s supposed to do Because most users have no need for redundant cypher implementations one of the AES drivers and two of the Twofish drivers are stored in the alternate_drivers directory To use these drivers simply copy them into the same directory as your FreeOTFE4PDA exe executable Please note 1 When mounting a volume FreeOTFE4PDA will just use the first combination of drivers it finds which will successfully decrypts your volume s critical data block CDB unlike the PC version the user isn t yet offered a choice of which successful driver to use To force FreeOTFE4PDA to use a particular driver for mounting please remove all drivers which implement the same algorithms as you wish to use from the directory FreeOTFE4PDA exe is stored in 2 Placing multiple drivers which implement the same hash cypher algorithms in the FreeOTFE directory can significantly slow down the time it takes to mount volumes The is because for security reasons FreeOTFE doesn t store any information relating to the hash cypher used to a secure a volume which forces it to cycle through all possible hash cypher combinations in order to determine which one to use Reducing the number of combinations it has to check by removing redundant hash cypher drivers reduces the time and has no impact on the level of security offered
114. e FAQ How can I speed FreeOTFE up when mounting my volumes Other drivers can be easily enabled if required To enable or disable a hash cypher driver 1 From the main menu select View 2 Select Options 3 Select either the Hashes or Cyphers tab as appropriate 4 Select which of the hash cypher drivers you would like enabled 31 FreeOTFE4PDA et 13 45 ok Please select which cypher drivers should be enabled Note The more drivers you enable the slower volume mounting will be AES libtomeryot library CAST6 Gladman library DES MARS Gladman library RC6 Gladman library RC6 flibtomerypt library Serpent Sorc library Drivers selected 1 General 2 Hashes Cyphers Done s Cancel General 1 Options dialog enabling disabling cypher drivers 32 6 Portable Mode A This section applies to the PC version of FreeOTFE only US Portable mode allows you to use FreeOTFE without first installing it on your computers hard drive To start portable mode simply 1 Uncompress the FreeOTFE release ZIP file version into a suitable location 2 Run FreeOTFE exe by doubleclicking on it 3 Select the Tools Portable mode drivers option or click on the world icon on the toolbar To stop portable mode select the Tools Portable mode drivers option or select the world icon on the toolbar again No files are copied to your hard drive when startin
115. e SUSE tee Drive Use default a EA Salt length 256 v bits C Mount readonly a Key iterations 2048 v Advanced security details pa Mountpoint FreeOTFE storage Salt length 256 al bits Key iterations 2048 iS Mount options Volume options Basic Advanced Mount as Fixed disk v Offset jo bytes Done Cancel Mount for all users de PC version PDA version Advanced mount options 5 5 1 Advanced Security Details 5 5 1 1 Salt length This should be set to the number of salt bits used in the PBKDF2 processing of the user s password before using it to decrypt the volume s CDB keyfile being used By default this is set to 256 bits the same default length used when creating a new volume 27 5 5 1 2 Key iterations This should be set to the number of key iterations used in the PBKDF2 processing of the user s password before using it to decrypt the volume s CDB keyfile being used By default this is set to 2048 iterations the same default number used when creating a new volume 5 5 1 3 PKCS 11 secret key This option is only available if PKCS 11 support is enabled see the section on Security Token Smartcard Support for more information on how to use this setting 5 5 2 Mount Options PC version only 5 5 2 1 Mount as FreeOTFE volumes may be mounted as any of the following types of virtual drive Fixed disk Removable disk e CD e DVD Under normal operation users should select eit
116. e blowfish modprobe cast5 modprobe cast6 modprobe cbc modprobe crc32c modprobe crypto_algapi modprobe crypto_hash 70 modprobe cryptomgr modprobe crypto_null modprobe deflate modprobe des modprobe ecb modprobe gf128mul modprobe hmac modprobe khazad modprobe lrw modprobe md4 modprobe md5 modprobe michael_mic modprobe serpent modprobe shal modprobe sha256 modprobe sha512 modprobe tea modprobe tgr192 modprobe twofish_common modprobe twofish modprobe wp512 modprobe xcbc dm_mod should give you dm_snapshot dm_zero and dm_mirror modprobe dm_mod modprobe dm_crypt At this point typing dmsetup targets should give you something along the lines of crypt v1 0 0 striped v1 0 1 linear VT s Oiesdi error vis 061 Typing Ismod will show you which modules are currently installed 9 10 2 Defaults If not overridden by the user LUKS defaults to encrypting with Cypher AES Cypher keysize 128 bit Cypher mode cbc plain Hash SHA 1 9 10 3 Example 1 Volume Encrypted Using LUKS s Default Encryption This example demonstrates use of a LUKS volume using the LUKS s default encryption system AES 128 with the user s password hashed with SHA1 using 32 bit sector IDs as encryption IVs Creating the volume file under Linux 71 dd if dev zero of volumes vol_default vol volumes vol_default vol cryptsetup luks losetup dev loop0 echo password1234567890ABC cryptsetup luks l
117. e booting Works ReadyDriver Plus Works EasyBCD May work Works 3 1 3 1 1 Test Mode on wallpaper The method with Yes marked in this column indicates that the words Test Mode will be shown in each of the four corners of the desktop wallpaper This is largely a cosmetic issue and can be resolved using the directions indicated in the description of this method 3 1 3 1 2 Junk messages shown on manual start Those methods with Yes marked in this column indicate that MS Windows will pop up a message stating Windows requires a digitally signed driver for each and every driver loaded even though the drivers are digitally signed albeit using self certification If the drivers are started automatically on booting these messages will not appear However if the FreeOTFE drivers are started from the GUI e g by starting portable mode Since FreeOTFE s flexible architecture employs multiple drivers this is hardly ideal as the user gets peppered with junk messages telling them what they re doing as if they didn t already know The number of these messages shown can be minimised by removing all unused hash and cypher drivers 3 1 3 2 Method 1 NOINTEGRITYCHECKS ON Instructions 1 Open an elevated command prompt by either Clicking the Start button on the Windows taskbar type CMD in the search box and then press lt CTRL SHIFT ENTER3 gt to run CMD with administrator privileges or
118. e driver in this way should be kept to the absolute minimum possible 145 13 5 Encrypted Partition Image Encryption Decryption The encrypted partition that forms the bulk of an encrypted volume is encrypted on a 512 byte sector by sector basis using The master key stored within the volume s CDB or keyfile A per sector IV provided that the cypher used has a fixed blocksize greater than zero 13 5 1 Per Sector IV Generation The manner in which per sector IVs are generated depends on the IV generation method the user selected when creating the volume IV Generation Method Description Null IV No IV is used a null IV is used i e A block of data consisting of with 0x00 null characters is used as the IV 32 bit sector ID The least significant 32 bits of the sector ID is right padded with 0x00 characters and used as the IV These bits are ordered MSB LSB 64 bit sector ID As the 32 bit sector ID method but a 64 bits sector ID is used Note This is unlikely to offer any security advantage over using 32 bit sector IDs unless used with a volume file 2 32 512 bytes long 2048GB or greater Hashed 32 bit sector ID The least significant 32 bits of the sector ID is hashed with the user s choice of hash algorithm The resulting hash value will be truncated right padded with 0x00 characters until it is the same length as the cypher s blocksize Hashed 64 bit sector ID As th
119. e hashed 32 bit sector ID method but a 64 bits sector ID is used Note This is unlikely to offer any security advantage over using 32 bit sector IDs unless used with a volume file 2 32 512 bytes long 2048GB or greater This option offers the most security On mounting the FreeOTFE volume the master key used for encrypting decrypting the volume is hashed with the hash algorithm chosen by the user when the volume was created If the cypher used for encryption decryption has a fixed keysize this hash output is truncated right padded with 0x00 characters until it matches the cypher s keysize and stored as the ESSIV key or salt If the cypher doesn t have a fixed keysize the full hash output is stored as this key salt When a per sector IV is required the 64 bit sector ID is encrypted using the ESSIV key This encrypted sector ID is truncated right padded with 0x00 characters until it matches the cypher s blocksize In all cases the sector ID is calculated as 146 Sector ID Ostart Soffset Ssize where The offset within the host volume partition from where the encrypted partition begins i e stan after any CDB Soffset The offset from within the encrypted partition from where the sector begins Ssize The sector size of the emulated drive i e 512 bytes is the modulus operator Putting it another way this is the sector ID starting from zero of the partition as
120. e key used for this encryption decryption depends on the CDB format used to create the CDB For older CDB format 1 volumes the key is derived as follows 1 The user s password is appended to the salt bits 2 The result is hashed with the user s choice of hash algorithm 3 If the cypher used has a fixed keysize this hash value generated is truncated right padded with NULLs until it is the same length as the cypher s keysize For newer CDB format 2 volumes the key is derived as follows 1 The user s password is passed through n iterations where n is user specified of PKCS 5 PBKDF2 using HMAC as the PRF which is turn employs the user s choice of hash algorithm In doing so the user s password is supplied as the password to PBKDF2 and the salt bits are used as the PBKDF2 salt 13 2 2 5 2 Check MAC The manner in which the check bytes within a CDB are calculated depends on the CDB format used For older CDB format 1 volumes the check bytes are calculated by simply hashing the volume details block with the user s choice of hash algorithm For newer CDB format 2 volumes the check bytes are calculated by passing the volume details block through HMAC with the user s choice of hash algorithm In doing so the derived key used to encrypt decrypt the CDB is used as the HMAC key 136 13 2 3 CDB Format ID 3 13 2 3 1 Overview A FreeOTFE critical data block consists of CDL bits of data The following table des
121. e length of salt used is stored anywhere in order to prevent an attacker from even knowing where the encrypted block starts within the CDB The Check MAC is limited to 512 bits This is limited for practical reasons as some kind of limit is required if the critical data block is to be of a predetermined size See section on mounting volume files for how multiple matching MACs are handled 135 The Password salt is fairly arbitrarily limited to 512 bits Again this is primarily done for practical reasons Although at time of writing March 2005 this limit to the length of salt used should be sufficient the format of the critical data block with included layout version ID does allow future scope for modification in order to allow the critical data block to be extended e g from 4096 to 8192 bits should this limit be deemed inadequate The Encrypted block does contain a certain amount of data that may be reasonably guessed by an attacker e g the CDB format ID however this would be of very limited use to an attacker launching a known plaintext attack as the amount of this data is minimal and as with pretty much any OTFE system the encrypted partition image can reasonably expected to contain significantly more known plaintext than the CDB anyway e g the partition s boot sector 13 2 2 5 1 CDB Encryption The encrypted data block within a CDB is encrypted using A key derived from the user s password e ANULLIV Th
122. e some form of recognisable structure or signature somewhere within it 2 Having several GB of high entropy data stored on your HDD together with an OTFE package is likely to be viewed as suspicious at the very least 10 2 Legal Issues Legally the presence of large volume files even without any form of signature may very well be viewed as grounds for reasonable suspicion to be raised in which case further action may be taken by an attacker e g arrest interrogation beating torture and other rubber hose cryptanalysis techniques Obviously if reasonable suspicion can be raised this simplistic approach provides very little in the way of plausible deniability Legally in the US at least and in theory what it really boils down to is does the fact that a prosecution cannot prove that the data held is encrypted data together with a user s denial produce reasonable doubt as to whether the data is not an OTFE volume or not Raising reasonable doubt as to what your volumes files really are is the aim of plausible deniability leaving it up to the prosecution to prove beyond reasonable doubt they store encrypted data In the UK AIUD things are slightly different with the Regulation of Investigatory Powers Act RIPA see http www legislation hmso gov uk acts acts2000 20000023 htm Depending largely on how the courts may interpret it a user as defendant may eventually find yourself in the position of effectively ha
123. e the volume was last written to Note This bit gets ignored by the GUI which will operate it according to the user options set at the time the volume is mounted Encrypted partition image length This stores the length of the encrypted partition image in bytes Master key length This will be set to the length of the master key in bits Master key This is set to the random data generated when the volume was created and is the en decryption key used to encrypt the encrypted partition image Requested drive letter The drive letter the volume should be normally be mounted as Set to 0x00 if there is no particular drive letter the volume should be mounted as i e mount using the first available drive letter Volume IV length This will be set to the length of the Volume IV in bits If the cypher s blocksize is gt 0 this will be set to the cypher s blocksize Otherwise this will be set to 0 Volume IV If cbs gt 0 then cbs If cbs lt 0 then 0 This is set to the random data generated when the volume was created When each sector of the encrypted partition is encrypted decrypted this value will be XORd with any hashed or unhashed sector ID before being used as the sector IV This guarantees that every sector within the encrypted partition has a non predictable IVs 140 This is set to indicate the method of generating sector IVs Note that if a volume IV i
124. ed partitions on a USB drive unless it s the first Q Why can t I use encrypted partitions on a USB drive unless it s the first partition A MS Windows has a limitation which prevents it from correctly using partitions on USB drives that are beyond the first one As a result the current version of FreeOTFE cannot use these partitions and this is indicated by displaying such partitions in red or not at all in the partition selection display If you wish to use an encrypted partition on a USB drive under both Windows and Linux please ensure that the encrypted partition is the first partition on the USB drive It should be noted that this limitation only applies to USB drives and not physical disks installed inside the PC A solution which will allow FreeOTFE to use second and other partitions on USB drives is currently under development Other possible solutions information may be found at Why is it not possible to partition a USB Flash Stick Multi partition a USB flash drive in Windows Removable Media Bit Q After creating an encrypted partition disk MS Windows reports that partition I used as being type RAW and prompts me to format it why A After creating an encrypted partition disk if you have a drive letter associated with the physical partition used MS Windows will report that drive as being RAW since it cannot understand what is stored on it for obvious reasons it can t understand what the enc
125. ed to overwrite the mounted volume s free space any attacker attempting to identify a hidden volume even with the key to the outer host volume would not be able to differentiate between your encrypted pseudorandom data and an encrypted hidden volume 77 This all assumes the cypher used is strong enough of course For obvious reasons all such overwriting must be carried out before the hidden volume is created doing so afterwards would probably corrupt your hidden volume 10 5 In Practice Needless to say FreeOTFE offers full functionalty with overwriting and the encryption of random data used To ensure the maximum security for your volumes the following procedure is suggested after creating each new volume 1 Mount the new volume 2 Select the new volume just mounted and then select the Tools Overwrite entire drive menuitem Note The Overwrite free space option should not be selected for this purpose as this will miss overwriting parts of the volume which the filesystem reserves 3 Doublecheck that you have selected the right volume and confirm your actions at the prompt displayed 4 Select Encrypted data and a suitable cypher from the dropdown list Note that the cypher selected does not have to be the same as the one used to secure your volume 5 Click OK 6 Generate some random data to be used as the key for the cypher by waggling the mouse pointer over the space shown on the dialog disp
126. ed when the volume is mounted and used while under Linux 2 Format the volume using a filesystem MS Windows understands i e NTFS FAT FAT32 then although your Linux volume may well be mounted its contents will probably be unreadable 9 4 Cryptoloop Specific Information 48 9 4 1 Hash Selection Cryptoloop losetup Linux volumes use the hash of the user s key as the key used for reading writing to the encrypted volume 9 4 2 Cryptoloop and RIPEMD 160 If you pass H rmd160 to losetup in order to use RIPEMD 160 to process your password losetup s behaviour changes slightly The user s password is not simply hashed with RIPEMD 160 instead the following procedure is used 1 The user s password is hashed once using RIPEMD 160 2 A copy of the first 129 characters of the user s password is made 3 The capital letter A is prepended to the start of the copy 4 The resulting string is then hashed with RIPEMD 160 5 This hash is then appended to the first hash to produce 320 bits of data 6 The appropriate number of bits is taken from the result and used as the encryption decryption key For this reason FreeOTFE includes a RIPEMD 160 driver specifically modified RIPEMD 160 Linux Twice with A to carry out this form of hashing This does not appear to be documented the above logic was derived from examining util linux 2 12p diff one of the files included with loop AES 9 4 3 Cypher Selection If
127. ee the Command Line Interface section for full details of FreeOTFE s command line options Q On the options dialog what does the Save above settings to option do A This allows you to change where your FreeOTFE settings are stored in your user profile only accessible to you or with the FreeOTFE executable which is useful if you want to take FreeOTFE with you on a USB drive for example You may also choose to not save your settings in which case the next time you start FreeOTFE you will begin again with the default options Q Can I save my settings in the same directory as my FreeOTFE executable A Yes you can and this makes FreeOTFE more portable and easier to use if you want to take it with you on for example a USB drive There is only one exception though if you are using Windows Vista and have User Account Control UAC switched on you will not be allowed to store your settings with the FreeOTFE executable if it is stored under your Program Files directory This is due to one of the limitations imposed by Windows Vista s security system though you are still free to store FreeOTFE s settings in your user profile Q Where and in what order does FreeOTFE search for my settings 104 A If you have chosen to save your settings FreeOTFE will store them un a FreeOTFE ini file stored on your computer at your chosen location When it starts up FreeOTFE will attempt to locate this file and read in you
128. eeOTFE the Portable mode drivers menuitem will appear checked as FreeOTFE detects your portable mode drivers If you select this menuitem the previous portable mode drivers should be stopped and uninstalled as per normal clearing this menuitem ready for you to restart portable mode 6 1 Portable Mode and Removable Media You may wish to run FreeOTFE in portable mode from removable media such as a USB flash drive or similar In this way your copy of FreeOTFE can easily be transported and used on different computers In order to do so the following files should be copied onto your flash drive 1 The main FreeOTFE GUI FreeOTFE exe 2 The main FreeOTFE driver FreeOTFE sys 3 At least one hash driver FreeOTFEHashxYZ sys 4 At least one cypher driver FreeOTFECypherxYZ sys Please note that if you attempt to start portable mode on a computer which already has one or more of the FreeOTFE drivers installed FreeOTFE will display an error stating that it cannot start the relevant driver in portable mode which is hardly surprising if it s already there 34 7 Security Token Smartcard Support j A This section applies to the PC version of FreeOTFE only FreeOTFE supports all security tokens smartcards referred to as tokens in this documentation which conform to the PKCS 11 aka Cryptoki standard providing two factor authentication of FreeOTFE volumes There are two ways in which tokens can be used
129. em Start PORD 0x00000003 Driver started manually Type DWORD 0x00000001 This value is optional but set to OxO0000001 if present Portable DWORD This value flags that the relevant driver was installed in portable mode and should be removed 147 The PDA version operates in a similar manner though no registry entries are created automatically by the OS for the drivers used Instead FreeOTFE4PDA is required to create a sequence of registry entries when a volume is mounted These registry entries are deleted once the volume is dismounted 13 7 Portable Mode Impact A This section applies to the PC version of FreeOTFE only ta Although no files are copied to your computers hard drive when using portable mode because part of the manner in which MS Windows manages device drivers Windows still writes certain details about the portable mode drivers to the registry Specifically the full path and filename of the drivers used together with other basic information on the drivers as detailed above When portable mode is stopped most of this information is deleted by Windows automatically However 1 Because of the way in which the registry stores data an attacker may be able to recover that information which has been deleted this is analogous to deleting a file on your filesystem although its directory entry may have been marked as deleted the data may still be recoverable 2 When Windows deletes its re
130. ength of MAC generated 13 2 3 2 Breakdown CDB layout Encrypted block Random padding 1 Item name Size in bits Description sl This data is used together with the user s password to derive the Password salt User specified critical data key This key is then used to encrypt decrypt the to a max 512 Encrypted block If cbs gt 8 then CDL sl div cbs cbs If cbs lt 8 then CDL sl This block contains the actual key which is used to Encrypted encrypt decrypt the encrypted partition image block essen te See below for further breakdown This size is referred to as leb Random Random padding data Required to pad out any remaining CDL sl leb padding 1 unused bits in the critical data block Total size CDL 138 13 2 3 3 Breakdown Encrypted block layout Check MAC Random padding 3 Volume details block As described above this entire block is encrypted using the user s password salt and chosen hash and cypher algorithms As this block is encrypted its length in bits must be a multiple of the cypher s blocksize Item name Size in bits Description This is the MAC of the plaintext version of the Volume details block ml Check MAC Up to a maximum f If hk is zero or undefined then this hash will be either truncated of MML bits to MML bits or right padded with 0 bits up to a maximum of MML bits Random Random pad
131. er filename gt all drivers in the current working directory Uninstall specified driver or all installed drivers Note that this takes the driver name not the drivercontrol uninstall drivername lt driver name gt all driver s filename Important Don t attempt to uninstall drivers which are currently in use e g by a mounted volume When dismounting force S EOLCE dismount emergency dismount The specified volume is a FreeOTFE volume If a volume freeotfe type FreeOTFE Linux isn t specified the user will be prompted for this information Keyfile to be used when mounting a FreeOTFE volume Only valid when mounting FreeOTFE volumes keyfile lt keyfile gt Only valid when mounting Linux LUKS volumes If this flag is specified the keyfile will be treated as containing ASCII password Otherwise the keyfile will be treated as containing binary data Default is to treat as binary keyfileisascii Only valid when mounting Linux LUKS volumes If keyfileisascii is specified the keyfilenewline CRLF LF CR first newline found in the keyfile will be treated as an EOF This option specifies what constitutes a newline Default is LF keyiterations lt keyiterations gt The number of key iterations File from which to read Linux encryption settings from Only valid when mounting non LUKS Linux volumes lesfile lt LES file gt 41 The specified volume is a Li
132. er one is selected must produce 4096 bits 512 bytes of cryptographically secure random numbers This random data is used in three ways 1 As the master key used for encrypting decrypting your data 2 For salting 3 As random padding to make up otherwise unused space within the FreeOTFE volume s critical data block See volume layout documentation for further details If more than one RNG is selected their output will be combined XOR d together and the resulting data used In this way the random data generated will never be weaker than the strongest selected RNG 13 8 1 Microsoft CryptoAPI The Microsoft CryptoAPI is used to generate random data 13 8 2 Mouse Movement This relies on the user waggling the mouse in a random fashion to generate random data Every 100ms the mouse pointer is checked If it has moved significantly then the X and Y coordinates of the mouse pointer are sampled and the LSB of each is added to the random data collected Due to the volume of random data required and the fact that only 2 bits of random data are collected for each mouse position sampled this is a relatively slow process 13 8 3 cryptlib cryptlib is used to generate random data Note This option is only available if cryptlib cl32 dll is installed see the eryptlib w WW site for further details and download 13 8 4 PKCS 11 Tokens If you have a security token or smartcard this may be used as a RNG See the Security
133. erence implementation of Twofish http www schneier com twofish html Oliver Taylor for the PKCS 11 and partition display implementation and his work on the drivers OSR Online a good resource for those writing device drivers Peter Gutmann pgut001 cs auckland ac nz for the cryptlib library which if installed FreeOTFE can take advantage of an RNG Clemens Fruhwirth http clemens endorphin org author of the LUKS specification and ESSIV David Saunders dsaunders gawab com for setting up the FreeOTFE org domain registration and WWW site Gianluca Varenni for his USENET post way back in August 2002 relating to the _alldvrm driver problem under MS Windows 2000 and the solution he used Dr Brian R Gladman gladman seven77 demon co uk for his implementation of the 2nd round AES candidates Lars B Dybdahl Lars dybdahl dk and Peter Th rnqvist peter3 peter3 com for dxgettext an Delphi port of GNU s gettext Alexander Okorokov oraclex mail ru for feedback and code improvements Brian Smith bsmith ringcube com for identifying tracking down and debugging an intermittant driver issue which could cause crashing when dismounting 18 1 Translations Language Translator German Volkmar Brandmaier brandmaier gmx net Italian Daniele fuzzee virgilio it French Daniel Berthereau Daniel fr Berthereau net Spanish Luis Santalla luis santalla hotmail com Czech Tomas Ruzicka tr3027
134. erence to the level of security FreeOTFE offers simply disable any redundant cypher hash implementation drivers such as either one of 116 FreeOTFE4PDACypherAES_Gladman dll FreeOTFE4PDACypherAES_Itc dll and any two of FreeOTFE4PDACypherTwofish_Gladman dll FreeOTFE4PDACypherTwofish_HifnCSs dll FreeOTFE4PDACypherTwofish_lItc dll Please see Advanced Topics Enabling Disabling Hash Cypher Algorithms section for instructions on how to enable disable hash cypher drivers Please see the FAQ on duplicated drivers for an explanation as to why multiple implementations are included in the release The mount time can be reduced even more dramatically by disabling all of the hash cypher drivers except for the ones which you have secured your data with This however could decrease the level of security offered as doing so would make it pretty clear to any attacker which combination you ve used though it s debatable whether this loss in security will actually be of any practical value to an attacker To speed things up even further you could drop the number of key iterations your volume is secured with This isn t particularly recommended but might help some users Q Does the PDA version support Linux volumes A Yes FreeOTFE4PDA v4 0 and later support LUKS volumes A front end interface to allow support for other Linux encrypted volumes is currently being implemented and will appear in a later release Q
135. ersions of FreeOTFE which use a later CDB layout in any case 129 To mount a FreeOTFE volume the following information must be determined ONAN NN PWN The location of the critical data block within the volume file The user s password The length of salt used in bits sl The algorithm used to hash the user s password and salt The cypher used for all en decryption operations The master key to be used to en decrypt the encrypted partition image The method used to generate the different IVs for each sector of the encrypted partition image The length of the encrypted partition image Items 1 3 are obtained by asking the user Items 3 and 4 are determined by brute force by hashing the user s password with the first sl bits of the critical data block with each of the hash algorithms installed then using that information to decrypt the remainder of the critical data block using each of the installed cyphers in turn After each decryption the decrypted critical data block is hashed and this hash value is compared to the decrypted version of the check hash Items 6 8 are then taken from the successfully decrypted critical data block and the volume is mounted In detail the following procedure is used 1 2 3 4 The user is prompted for the following information The volume s password The drive letter they wish to mount the volume as Incase the user opted to change the default amount of salt
136. ersions of FreeOTFE default this value to 256 bits and you may well have to change this to the previous default of 128 bits When mounting FreeOTFE volumes FreeOTFE will attempt to mount using the latest CDB format only falling back and attempting to mount using the older CDB format if this fails Although FreeOTFE is backward compatible with existing volumes it is very highly recommended that you update your volume files to ensure that they use the new CDB format as this will allow you to take advantage of the numerous security improvements that the latest version provides The easiest way to update your volume files to the new CDB format is to simply change their passwords by selecting Tools Change volume keyfile password details IMPORTANT If you created any les Linux Encryption Settings files please double check the next time you reload them and ensure that your settings are correct Changes due to ongoing development may cause some settings to change to fix simply confirm your settings are correct and save them out again 3 1 3 Additional Information for Windows Vista x64 and Windows 7 x64 Users Only This section applies to the PC version of FreeOTFE when run under the 64 bit x64 version of Windows Vista and Windows 7 only This section does not apply to 64 bit PCs running the 32 bit version of Windows Vista or Windows 7 or when running the x64 version of Windows XP In order to protect its revenue streams
137. est_mountpoint cp test_files SHORT_TEXT txt test_mountpoint cp test_files BINARY_ZEROS dat test_mountpoint cp test_files BINARY_ABC_RPTD dat test_mountpoint cp test_files BINARY_OO_FF_RPTD dat test_mountpoint umount test_mountpoint losetup d dev loopl cryptsetup luks luksClose myMapper losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the losetup volume file 3 In the dialog shown enter password1234567890ABC as the key and set any of the options wanted 4 Click the OK button 9 10 6 Example 4 Volume Encrypted Using 256 bit AES XTS This example demonstrates use of aLUKS AES 256 volume in XTS mode Creating the volume file under Linux 73 dd if dev zero of volumes vol_aes_xts vol bs 5M count 1 losetup dev loop0O volumes vol_aes_xts vol echo password1234567890ABC cryptsetup luks c aes xts plain s 512 luksFormat dev loop0 cryptsetup luks luksDump dev loop0 echo password1234567890ABC cryptsetup luks luksOpen dev loop0 myMapper dmsetup 1s dmsetup table dmsetup status cryptsetup luks status myMapper losetup dev loopl dev mapper myMapper cat test_files 2MB_Z dat gt dev loopl cat test_files 2MB_0x00 dat gt dev loopl mkdosfs dev loopl mkdir test_mountpoint mount dev loopl test_mountpoint cp test_files SHORT_TEXT txt test_mountpoint cp test_files BINARY_ZEROS dat
138. etails of the hash algorithms it provides the blocksize returned for each hash algorithm must be one of the following 157 Hash blocksize Validity Meaning Comments Hashes may only have a blocksize of 0 bits if the length of the hash values they output is also 0 bits long or if they ignore their input Hash algorithm does not Hashes which use zero length blocksizes process input data cannot be used for FreeOTFE volumes FreeOTFE volumes use HMAC which requires that the blocksize of hashes used is greater than zero Hashes which use variable length blocksizes cannot be used for FreeOTFE volumes FreeOTFE volumes use HMAC which requires that the blocksize of hashes is a fixed size Less than Hash algorithm processes input 0 data in variable length blocks Hash algorithm processes input data in defined fixed blocks e g SHA 512 s block size is 1024 bits Must be a multiple of 8 13 10 2 Cypher Keysize Blocksize When your hash driver is asked for details of the cyphers it provides the keysize returned for each cypher must be one of the following Cypher kevsize Validity Meaning Comments No key is used during encryption e g if the cypher doesn t encrypt data just returns the plaintext as the cyphertext or if the cypher uses a hardcoded key Less than 0 The cypher takes variable keylengths e g the XOR cypher Greater The cypher accepts only a specific
139. ey tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the RIPEMD 160 Linux Twice with A hash Make sure that the Hash with A s if hash output is too short is not checked Leave iteration count at 0 4 Encryption tab Select the AES CBC 256 128 cypher Select the 32 bits sector IV IV generation method Set Sector zero location to Start of host file 5 File options tab Leave offset at 0 Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button 58 9 8 8 E Value xample 6 Volume Encrypted Using 256 bit AES and Seed This example demonstrates use of a Linux AES256 volume with seeding The seed used here is the string seedvalue Creating the volume file under Linux dd if dev zero of vol_aes256_seeded bs 1k count 1024 losetup e AES256 S seedvalue dev loop0 vol_aes256_seeded Ente r password password1234567890ABC losetup a mkdosf mkdir mount echo s dev loop0 test_mountpoint dev loop0 test_mountpoint This is a text test file gt test_mountpoint SHORT_TEXT txt cp TES _FILE_1 dat test_mountpoint cp TES _FILE_2 dat test_mountpoint cp TES umount _FILE_3 dat test_mountpoint dev loop0 losetup d dev loop0 rm SE Mounting test
140. for this reason you cannot create a dm crypt volume under Linux using 256 bit Twofish and specify SHA 512 as the ESSIV hash Twofish doesn t support 512 bit keys and so dm crypt fails 9 6 LUKS Specific Information As LUKS is based on dm crypt please see also the section above relating to dm setup FreeOTFE supports LUKS to v1 1 of the LUKS specification This is the latest version at time of writing 2nd December 2007 As well as using the File Linux Mount file partition menu items LUKS volumes may also be mounted using the main File Mount file partition menu items and toolbar buttons FreeOTFE detects LUKS volumes by their signature and offers to mount them appropriately 9 6 1 ESSIV FreeOTFE supports LUKS with ESSIV subject to the condition that the ESSIV hash used generates hashes with the same or less bits than the cypher s block size Also at time of writing 25th February 2007 the current LUKS implementation of cryptsetup only supports the SHA1 hash algorithm although other hashes may be used for ESSIV 51 Because of the way in which dm crypt operates see also the dm crypt section on ESSIV above LUKS ESSIV doesn t do what you d probably expect it to do Specifically if you have for example a Blowfish 448 encrypted volume and specify cbc essiv sha256 for use as Vs LUKS dm crypt will actually use Blowfish 256 as the ESSIV cypher and not Blowfish 448 In other words the ES
141. fore they can be modified in this way An option is included to dump out a human readable version of the volume s critical data block keyfile s contents select Tools Critical data block Dump to human readable file This option is primarily intended to assist developers and to future proof volumes file by giving you access to the actual master encryption decryption key used by the volume it dumps out It should be noted that the inclusion of this option does not present a security risk as it requires that the user to enter the volume keyfile s password immediately before it can operate obviously the volume keyfile s password is needed in order to decrypt the critical data block If an attacker has your volume keyfile s password clearly this option will give no further information away A Revert timestamps option is available from the Options dialog If selected on mounting a volume file its timestamps will be noted When the volume is subsequently dismounted these timestamps will be restored By default the PC version of FreeOTFE and FreeOTFE Explorer have this option switched on and the PDA version FreeOTFE4PDA has it switched off If you are going to use both the PC and PDA software with the same volume file syncing between the two platforms it is recommended that this option is turned off on both your PC and PDA installations in order for ActiveSync to recognise when your volumes have been modified A password is not
142. format lt cypher name gt lt mode gt lt key size gt lt block size gt Note The key and block sizes shown are in bits not bytes For example AES XTS 256 128 This indicates that the cypher is AES operating in XTS mode with a key size of 256 bits and a block size of 128 bits If the key size shown is zero then the cypher does need take a key password to carry out encryption e g the Null test cypher If the key size shown is 1 then the cypher can accept keys of arbitrary size If the block size is 1 then the cypher encrypts decrypts arbitrary block size Typically when presented with a selection of different cyphers to choose from you will see a or button next to the list clicking this button will display full details on the driver Q When creating a new volume file why do I get a message asking me to ensure I have XX XX GB free on the relevant drive A If you get an error stating that Unable to create volume file please ensure you have XX XX GB free on the relevant drive during volume creation this is probably because the drive you are trying to create the volume on is formatted as FAT FAT32 both of which have a file size limit of 4GB Please see the FAQ II tried to create a large volume gt 4GB and FreeOTFE stopped halfway through with an error why Q I tried to create a large volume gt 4GB and FreeOTFE stopped halfway through with an error why A The most probab
143. from the old volume to the new one 5 Dismount both volumes 6 Delete the old volume Obviously this procedure requires enough storage space to hold both the old and newly created volumes 97 It should be noted that although a number of other disk encryption systems claim to offer volume resizing functionality they typically either carrying out the procedure above behind the scenes often failing completely if insufficient storage is available to hold the new volume or by storing the volume in a sparse files which can lead to security leaks Q How do I delete an encrypted volume A If your volume is stored within a file simply dismount the volume if already mounted and delete the file IMPORTANT Before deleting a volume file make sure that you mount it first and copy any information stored in it to somewhere safe Once deleted you will lose access to your encrypted volume and anything it contains Q How do I backup an encrypted volume A How you backup an encrypted volume depends on whether it is a file or partition based volume In both cases however volumes should be dismounted before being backed up For file based volumes A file based volume is a file just like any other albeit a fairly big one simply let your backup software backup the volume as it chooses and your data should be safe This will work regardless of what backup software you use though you may wish to turn off FreeOTFE s timestamp
144. g stopping portable mode Administrator rights are required in order to start and stop portable mode You can still use FreeOTFE on a computer which you do not have Administrator rights on but will need to ask an Administrator to install it for you first see the installation section for further details Alternativly use FreeOTFE Explorer instead which doesn t need drivers at all You can check to see which drivers are operating in portable mode by selecting File Drivers those drivers currently running in portable mode are with a small world icon to the left of their names IMPORTANT Stopping portable mode when any mounted volumes are still using one or more FreeOTFE drivers operating in portable mode can cause unexpected results for this reason it is recommended that you dismount all volumes before stopping portable mode For safety reasons drivers installed in portable mode are installed such that if you reboot your system without first stopping portable mode via the FreeOTFE interface those drivers will not automatically start up when your computer comes back up If they were automatically restarted and your portable drivers were stored on removable media which was taken out while rebooting possible problems could occur during your boot sequence 33 Because of this if you exit FreeOTFE without stopping all portable mode drivers and then reboot your computer you will find that the next time you launch Fr
145. generated by DRM protected content Microsoft saw fit to require all drivers running under the 64 bit x64 version of Windows Vista and Windows 7 be digitally signed by Microsoft s root certificate Understandably this presents a major problem for the overwhelming majority of free software projects which make use of kernel mode drivers which for obvious reasons don t such a have a digital certificate read haven t paid Microsoft or one of their resellers for such a certificate to sign their drivers with For the same reason FreeOTFE s drivers are not currently signed with a Microsoft certificate Fortunately there are a number of methods of loading unsigned drivers under Windows Vista x64 Windows 7 x64 without having to pay for a digital certificate and these are summarised below As a consequence it is possible to use FreeOTFE under Vista x64 Windows 7 x64 by using the methods shown as be successful below A more long term solution Microsoft signing is being investigated 3 1 3 1 Summary of Different Methods Below is a table summarising the different methods of configuring Windows Vista x64 Windows 7 x64 to allow it to run FreeOTFE For most users Method 3 TESTSIGNING ON is recommended Test Junk Mode messages on shown on wallpaper manual start Results Recommended NOINTEGRITYCHECKS ON Ineffective Yes DISABLE_INTEGRITY_CHECKS M2v work Yes TESTSIGNING ON Works lt F8 gt whil
146. gistry entries it doesn t delete all of them e g HKLM SYSTEM CurrentControlSet Enum Root LEGACY__ It is not possible to securely delete the relevant registry entries without going behind Windows back not exactly recommended when working with kernel mode device drivers It should be noted that this applies equally to all disk encryption systems that support any kind of portable mode Should it be a concern that an attacker may discover which FreeOTFE drivers were being used it is suggested that you either 1 Change the filenames of the FreeOTFE drivers you will be using in portable mode e g rename FreeOTFECypherAES sys to FreeOTFECypherTwofish sys This will cause the data written to the registry to reflect this new filename hopefully convincing an attacker that the driver used was a different one 2 If you only use one cypher and hash driver in portable mode store a number or all of the other cypher hash drivers with your portable version of FreeOTFE Even if an attacker can determine which drivers you were using in portable mode that attacker will not be able to determine which of the portable drivers you were actually using to encrypt decrypt your data with 13 8 Random Number Generators RNGs FreeOTFE offers a choice of four different random number generators RNGs for use when creating new FreeOTFE volumes 148 1 Microsoft CryptoAPI 2 Mouse movement 3 cryptlib 4 PKCS 11 tokens Whichev
147. he new two item menus at the bottom of my display how do I change them back to the older toolbar style menu I don t like the multi item menubar toolbar at the bottom of FreeOTFE4PDA s display how do I get it to use the newer two item style softkey menus instead Can I use my PC volumes with the PDA version I upgraded to the lastest version of FreeOTFE4PDA can I still mount my old volumes I would like to use hash cypher XYZ why doesn t it appear as an option How to I enable hash cypher XYZ 12 1 4 FreeOTFE Explorer Specific Does FreeOTFE Explorer support drag and drop with MS Windows Explorer Can Does FreeOTFE Explorer support drag and drop with MS Windows Explorer What filesystems does FreeOTFE Explorer support Does FreeOTFE Explorer try to connect to the internet How do I securely overwrite files stored on a flash drive 85 How do I get FreeOTFE Explorer to display filename extensions for all files Can FreeOTFE Explorer run under Linux 12 2 General Q Whare are the differences between FreeOTFE and FreeOTFE Explorer A Please see the FreeOTFE v FreeOTFE Explorer Comparison Q How can I help the FreeOTFE project A If you are a native speaker of a language other than English please take a look at translating FreeOTFE page FreeOTFE v4 3 introduced support for translating the user interface into different languages though at present the actual number of translations into other language
148. he user s password is appended to the salt bits 2 The result is hashed with the user s choice of hash algorithm 3 If the cypher used has a fixed keysize this hash value generated is truncated right padded with NULLs until it is the same length as the cypher s keysize For newer CDB format 2 volumes the key is derived as follows 1 The user s password is passed through n iterations where n is user specified of PKCS 5 PBKDF2 using HMAC as the PRF which is turn employs the user s choice of hash algorithm In doing so the user s password is supplied as the password to PBKDF2 and the salt bits are used as the PBKDF2 salt 13 2 3 5 2 Check MAC The manner in which the check bytes within a CDB are calculated depends on the CDB format used For older CDB format 1 volumes the check bytes are calculated by simply hashing the volume details block with the user s choice of hash algorithm For newer CDB format 2 volumes the check bytes are calculated by passing the volume details block through HMAC with the user s choice of hash algorithm In doing so the derived key used to encrypt decrypt the CDB is used as the HMAC key 13 2 4 CDB Format ID 4 CDB layout format 4 is identical to CDB layout format 3 with the one exception that the Master key stored within the Volume details block may include multiple keys one after the other For example AnLRW encrypted volume s Master key will be the encryption key f
149. her fixed disk or removable disk Selecting the removable disk option causes the volume to be mounted as though it was a removable drive By mounting volumes in this way among other things files deleted from your volume will not be moved to a recycle bin on your encrypted volume but will be deleted immediately By default FreeOTFE mounts volumes as a fixed disk 5 5 2 2 Mount for all users If this option is checked mounted drives will be visible to all users logged onto the PC By default this option is checked 5 5 2 3 Volume Options These options are intended for use with hidden volumes and volumes which were created without a CDB embedded at the start of the volume Offset When attempting to mount a hidden volume this should be set to the offset in bytes where the hidden volume starts as specified when creating it By default this is set to an offset of O bytes 28 Data from offset includes CDB This checkbox is only enabled if a keyfile has been specified If you are attempting to mount either a hidden or normal volume which was created without a CDB embedded at the start of the volume this checkbox should be changed so that it is unchecked For mounting all other volumes this checkbox should be checked By default this checkbox is checked 5 5 3 Mountpoint PDA version only This is the name of the new folder where the mounted volume will appear For example you may already have a mountpoint
150. ile 3 Key tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the SHA 512 512 1024 hash Make sure that the Hash with A s if hash output is too short is not checked Leave iteration count at 0 4 Encryption tab Select the AES CBC 256 128 cypher Select the 32 bits sector IV IV generation method Set Sector zero location to Start of host file 5 File options tab Change offset to 2560 bytes Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button 9 8 10 Example 8 Volume Encrypted Using 256 bit Twofish This example demonstrates use of a Linux Twofish 256 bit volume Creating the volume file under Linux 60 dd if dev zero of vol_twofish256 bs 1k count 1024 losetup e twofish256 dev loop0O vol_twofish256 Enter password password1234567890ABC losetup a mkdosfs dev loop0 mkdir test_mountpoint mount dev loop0 test_mountpoint echo This is a text test file gt test_mountpoint SHORT_TEXT txt umount dev loop0 losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume file 3 Key tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the SHA 512 512 1024 hash Make sure
151. ile 5 Decrypt the sector block by block The key used here is hard coded in the source and must be the actual key that was used to encrypt the data obviously The way in which decryption is carried out is cypher and cypher implementation dependant 6 Write the decrypted sector to the output plaintext file Repeat steps 3 6 until all data has been decrypted 8 Close the output file 183 9 Close the input file Please note 1 This software is focussed only on decrypting data They do not hash user keys etc 2 The hard coded keys must represent the actual encryption keys In the case of Linux volumes this is the user s password hashed as appropriate In the case of FreeOTFE volumes this is the master key stored in the volume s critical data block At time of writing although a separate command line decryption utility to decode a FreeOTFE volume s CDB keyfiles has not been implemented the FreeOTFE GUI does incorporate this functionality allowing developers to extract all of the information required contained within a CDB keyfile Note For obvious reasons this requires the volume s password and all other details that are required to use the CDB are known it is simply not possible to decrypt this information otherwise 184 23 Appendix G Uninstalling A This section applies to the PC version of FreeOTFE only US To uninstall FreeOTFE please carry out the steps detailed in either of the sections
152. ils block of the CDB used for mounting The first two items are determined by brute force by decrypting the CDB with every possible combination of hash cypher installed on the user s system until the CDB s Check MAC is decrypted successfully In detail the following procedure is used 1 The information listed above is obtained from the user 2 The 512 bytes 4096 bits CDB is read in This will be taken from one of 1 The start of the volume being mounted provided the volume includes a CDB 2 A host file starting from a user specified offset if mounting a hidden volume provided the hidden volume includes a CDB 3 Akeyfile relating to the volume being mounted 3 The first sl bits are stripped off the CDB and are assumed to be the salt 4 For each hash algorithm installed on the user s computer 1 For each cypher algorithm installed on the user s computer 1 A critical data key is derived by processing the user s password and salt with PKCS 5 PBKDF2 The PRF used with PBKDF2 will be HMAC with the current hash algorithm The derived key should be ks bits long i e the cypher s keysize If ks is undefined then 512 bits will be used 2 The number of Random padding 1 bytes is determined based on the cypher s blocksize This random padding is then stripped off the CDB to give an Encrypted block 3 The Encrypted block is decrypted using the critical data key generated above and 144 the current c
153. ing a computer which has been handling sensitive information and dumping contents of its memory out to a disk in order to try to examine information stored in memory immediately prior to rebooting This form of attack is detailed at http citp princeton edu memory This attack is nothing new and has been well known for a long time despite the disproportionate amount of attention it s now getting Solution If you mount an OTFE volume and simply walk away from your computer the encryption keys used to secure your volume will be held in your computer s physical memory obviously If someone reboots your computer at that point there is a risk they could successfully recover your encryption key However it is not generally recommended that you simply walk away from your computer while you have volumes mounted if anyone can come along and attempt to launch the above attack THEY CAN SIMPLY READ THE CONTENTS OF YOUR ENCRYPTED VOLUME DIRECTLY ANYWAY If you dismount your volumes after using them the FreeOTFE driver overwrites all sensitive data key information etc that it holds before releasing it which should prevent the above attack If you suddenly press your computer s power off button or reset it i e using the physical power off button on the front of its case while a volume is mounted then an attacker could theoretically dump out your encryption keys using this attack Please note that 1 All encryption systems a
154. ing circumstances 1 The first time you run FreeOTFE when no drivers have been installed 2 When exiting the driver installation dialog if the main FreeOTFE driver hasn t been both installed and started 3 When starting FreeOTFE after installing the main FreeOTFE driver if the driver has not been started e g you rebooted and the driver was set for manual start as opposed to at system startup 4 When stopping all portable mode drivers where the main FreeOTFE driver was started in portable mode 5 When exiting FreeOTFE and stopping all portable mode drivers where the main FreeOTFE driver was started in portable mode To eliminate this error message ensure that that the main FreeOTFE driver is installed and started To prevent this error message from being displayed when FreeOTFE is run after rebooting set the main FreeOTFE driver to start at system startup 102 The status of all installed drivers can be checked by selecting File Drivers Q Why do I get prompted to select a driver whenever I attempt to mount some of my FreeOTFE volume A If your volume looks as though it can be decrypted by using more than one cypher hash driver combination you will be prompted to select which combination you wish to use This happens for example if you used Twofish or AES to encrypt your data as FreeOTFE comes supplied with a choice of drivers for these cyphers see also Which of the duplicated drivers should I use
155. ions provided e g storing a volume s CDB separately to the volume file it relates to and how they operate 15 You may want to create and use multiple volumes one to store work related files one for personal files etc Do not simply copy an existing volume file to create a new one even if you change the password on the new volume If you do this both volumes will have the same encrypted master key which reduces the amount of security offered SECURITY 4 4 Mounting volumes Once you have created a volume it must be mounted in order for it to appear as a virtual drive on your computer Select File Mount file menuitem to mount a file based volume or File Mount partition to mount a partition based volume You will then be prompted to select which volume you wish to mount do so and click OK to display the password entry dialog You can also mount volumes by dragging and dropping the encrypted volume file onto the main FreeOTFE window FreeOTFE4PDA e 4 10 51 ok FreeOTFE Key Entry i E fiene JL Security details Password Keyfile E Hl passwort __ _ Mount readonly Keytile Eile PKCS 11 Drive Use default v C Mount readonly Basic Advanced Done Cancel PC version PDA version Password entry dialog 16 Enter your volume s password and click OK If the correct password has been entered the volume will be
156. it is strongly recommended that you go through the restore process at least once before setting it and forgetting it The absolute worst time for learning how your software s restore function works is when you actually need it e g after a disk failure and you want to get your data back This advice applies to ALL backups and not just backups of FreeOTFE volumes By doing a dry run you can have confidence in both your backups and in your ability to use them should you need to Q Can I use any filename file extension for my FreeOTFE volume A Yes Filenames and file extensions have no special meaning to FreeOTFE which means any filename can be used Q Does FreeOTFE support LVM2 A Yes it certainly can FreeOTFE fully supports Linux LVM2 volumes provided that you have a suitable Windows driver which allows access to LVM2 volumes this will allow FreeOTFE to carry out disk encryption either above or below the LVM management system i e on physical or logical volumes It should be noted however that LVM2 is not a disk encryption issue Q Is it worth running file overwriter shredder programs to securely delete existing data stored on my encrypted drive A For most users no it would only have the effect of replacing encrypted files with encrypted garbage neither is particularly useful to an attacker However if you have concerns of an attacker being able to gain your password and other details
157. ition Total size 13 2 2 4 Breakdown Volume details block layout Pnciypied Master Master Requested Volume Volume Random partition key padding iee lenei Ieuan key drive letter IV length IV 2 Finally we reach the details that the critical data block was designed to protect All of the items within this block have bit order MSB first Size in bits Description Item name This is a version ID which identifies the layout of the remainder of the CDB format ID volume details block When this layout format is used this will always be set to 2 Bitmap flagging various items Bit Description 0 Use different IVs for each sector 0 Use NULL IV for all sectors 1 Use sector ID possibly hashed see bit 3 as IV Volume flags 1 Sector ID zero is at the start of the file 0 Sector ID zero is at the start of the encrypted data 1 Sector ID zero is at the start of the host volume file 2 unused 3 Hash sector ID before use only valid if bit 0 is set 0 Use sector ID as sector IV do not hash before using 1 Hash sector ID before using as sector IV 134 Encrypted partition image length This stores the length of the encrypted partition image in bytes Master key length This will be set to the length of the master key in bits Master key This is set to the random data generated when the volume was created and is the en decryption key used to encrypt the
158. k Decrypt and select your volume keyfile 2 Change the password on it 3 Re encrypt the keyfile volume s CDB using the token s secret key using the encrypt function on the PKCS 11 token management dialog Q Can I use more than one security token with FreeOTFE A Yes FreeOTFE supports as many security tokens as you ve got You can even use different tokens to mount different volumes or the same token to mount multiple volumes all at the same time if you wish 113 The only caveat being that your PKCS 11 library provider may only support up to a certain number of security tokens being plugged in at the same time typically this may allow up to 16 tokens to be used simultaneously Q Why don t all of my volumes automatically dismount when I remove my security token A First please check that you have configured FreeOTFE to autodismount volumes on token removal by 1 Go to View Options 2 Select the PKCS 11 tab 3 Ensure that the Auto dismount PKCS 11 volumes when associated token is removed is checked If you dismount then remount your volumes with your PKCS 11 token they should be dismounted when it is removed Please note that only those volumes which were mounted with the removed token will be automatically dismounted More than one token may be used at the same time again only those volumes mounted with the removed token will be automatically dismounted Q Windows Vista only Why do
159. k them to sign the release not ideal 2 Find someone prepared to finance buying a digital certificate circa 450 EUR for three years which could be used The latter would probably be the best long term solution offers of help would be gratefully received please get in contact 3 2 PDA Version The PDA version may be installed using any of three different ways 1 By connecting your PDA to a PC making an ActiveSync connection and the running the ActiveSync installer 2 By copying the CAB file release to a memory card inserting it in your PDA and then tapping on the CAB file from File Explorer or similar 3 By uncompressing the ZIP file release and copying the executables exe and dll files to your PDA and then simply tapping on FreeOTFE4PDA exe 3 2 1 Faster mounting To reduce the time taken for FreeOTFE4PDA to mount volumes please see the FAQ How can I speed FreeOTFE up when mounting my volumes 3 2 2 Alternative drivers Most users can ignore this section it s only intended for more advanced users FreeOTFE4PDA comes with multiple AES and Twofish implementations specifically FreeOTFE4PDACypherAES_Gladman dll FreeOTFE4PDACypherAES_Itc dll for AES and FreeOTFE4PDACypherTwofish_Gladman dll FreeOTFE4PDACypherTwofish_HifnCSs dll FreeOTFE4PDACypherTwofish_lItc dll for Twofish These libraries all implement the same cyphers but are built from different crypto libraries They ar
160. k2ig dll cryptoki dll id2cbox dll Full path to library may be required e g C Data Development SmartCardIntegration PKCS11wrapper JavaToPKCS11 demo test old id2cbox dll Mozilla Netscape Mozilla or Netscape crypto module softokn3 dll Cannot be used with FreeOTFE requires additional parameters to initailize nCipher nFast cknfast dll nShield cknfast dll Nexus nxpkcs11 dll OpenSC multiple opensc pkcs11 dll Free open source library Orga Micardo micardoPKCS 1 1 dll 180 Rainbow CryptoSwift Accelerator Cryptoki22 dll CryptoSwift HSM iveacryptoki dll Ikey 1000 cryptoki22 dll From wiki cacert org for USB use Datakey driver iKey 1000 1032 k1pk112 dll iKey 2000 series and for DataKey cards dkck201 dll iKey 2000 2032 dkck232 dll iKey 2032 dkck201 dll cryptoki22 dll From wiki cacert org for USB use Datakey driver Safelayer HSM plicard dll From wiki cacert org for USB use Datakey driver Schlumberger Cryptoflex acpkcs dll Cryptoflex slbck dll Cyberflex Access slbck dll SeTokI cards SetTokI dll Full path to library may be required e g C Program Files Setec SetTokl SetTokI dll Siemens HiPath SIcurity Card siecap11 dll Some Siemens Card OS cards eTpkcs11 dll SmartTrust smartp11 dl
161. keysize e g full strength Must be a than 0 DES only accepts 64 bit keys multiple of 8 When your hash driver is asked for details of the cyphers it provides the blocksize returned for each cypher must be one of the following 158 Cypher blocksize Validity Meaning Comments Cypher does not process input data e g If the blocksize is 0 then no IVs the NULL cypher which just returns will be used for the supplied plaintext as cyphertext encrypting decrypting Cypher processes input data in variable length blocks e g XOR processes data in blocks with the same length as the key being used If the blocksize isn t fixed then no IVs will be used for encrypting decrypting Less than 0 Cypher processes input data in defined fixed blocks e g AES has a block size is Must be a multiple of 8 128 bits 13 10 3 Miscellaneous Comments Cypher Drivers When called upon to encrypt decrypt data if the VLength passed in is 0 then IV should be ignored it may be set to NULL When writing a cypher driver the encrypt decrypt implementation should not write to the input buffer only the output buffer i e when encrypting do not write to the plaintext buffer passed in when decrypting do not write to the cyphertext buffer An optimisation in the driver involves the use of a single buffer for input output You may find that you ll need to create a temporary buffer equal to you
162. l Spyrus SpyPK11 dll Utimaco Cryptoki for SafeGuard pkes201n dll 181 ActivCard cards acpkcs dll ActivClient acpkcs211 dll From wiki cacert org Datakey dkck201 dll for Entrust Datakey pkes201n dll Datakey CIP dkck201 dll i From wiki cacert org Datakey iKey dkck232 dll NB buggy use 201 Fortezza Module fort32 dll Oberthur AuthentIC AuCryptoki2 0 dll SCW PKCS 3GI 3 G International 3gp11csp dll TeleSec pkes11 dll The information listed above was compiled from multiple sources including e Acer Wiki Pees TaskTorcd StrongDisk Server Russian documentation e erypilib v3 1 eso J N AIKPkcs11 properties Using the IAIK JCE Provider for PKCS 11 182 22 Appendix F Command Line Decryption Utilities 22 1 Overview Note The development of the command line decryption utilities has ceased This functionality has been superceded with the development of FreeOTFE Explorer FreeOTFE is relatively unique in that comes complete with software which may be used to decrypt encrypted volumes provided the correct decryption key is known This software is designed to fulfil two main objectives 1 To increase and encourage peer review of FreeOTFE 2 To act as a security blanket for users should development of FreeOTFE ever be dropped it will still be possible for users to recover their data regardless of the sta
163. l in decrypting If exactly one cypher hash combination successfully decrypted the Volume details block then the Encrypted partition image will be decrypted as necessary using this cypher hash combination together with the information obtained from the decrypted Volume details block As a result of the CDB layout it is not necessary to store either the cypher or hash algorithm used for en decryption anywhere Nor is it necessary to prompt the user for this information as this information can be determined dynamically by attempting the mount using all possible combinations of installed hash cypher and testing if the same check MAC can be generated using the decrypted data 13 4 1 Additional information The driver API supports passing volume metadata to the driver when mounting a volume Information passed in this way to the driver is simply stored by the driver against the mounted volume and is not processed in any way When a user application calls DevicelOControl with IOCTL_FREEOTFE_GET_DISK_DEVICE_STATUS the number of bytes of volume metadata is returned By calling with IOCTL_FREEOTFE_GET_DISK_DEVICE_METADATA the actual data that was stored when mounting can be retrieved This is intended for future development to enable user applications to store information against volumes they mount e g This is a Linux volume This is a FreeOTFE volume which can later be retrieved for display to the user Volume metadata passed to th
164. ladman XTS version aka XTS AES 128 AES 192 128 CBC XTS Dr Brian R Gladman AES 256 128 CBC XTS Dr Brian R Gladman XTS version aka XTS AES 256 AES 128 128 CBC LRW XTS LibTomCrypt XTS version aka XTS AES 128 AES 192 128 CBC LRW XTS LibTomCrypt AES 256 128 CBC LRW XTS LibTomCrypt XTS version aka XTS AES 256 Blowfish 128 64 CBC LibTomCrypt Blowfish 160 64 CBC LibTomCrypt Blowfish 192 64 CBC LibTomCrypt Blowfish 256 64 CBC LibTomCrypt Blowfish 448 64 CBC LibTomCrypt CASTS 128 64 CBC LibTomCrypt aka CAST 128 CAST6 128 CBC Dr Brian R Gladman aka CAST 256 CAST6 160 CBC Dr Brian R Gladman aka CAST 256 CAST6 192 CBC Dr Brian R Gladman aka CAST 256 CAST6 224 CBC Dr Brian R Gladman aka CAST 256 CAST6 256 CBC Dr Brian R Gladman aka CAST 256 DES 64 CBC LibTomCrypt 3DES CBC LibTomCrypt Standard encrypt decrypt encrypt MARS CBC XTS Dr Brian R Gladman 128 CBC XTS Dr Brian R Gladman 128 CBC XTS Dr Brian R Gladman variable n a n a 128 CBC XTS Dr Brian R Gladman 128 CBC XTS Dr Brian R Gladman 128 CBC XTS Dr Brian R Gladman 128 CBC LRW XTS Lib
165. layed 7 Click OK 8 Click Yes to confirm you wish to proceed At this point the volume will be overwritten Depending on your hardware this process may take some time After the overwrite completes format the drive The new volume will then be ready for use To create a hidden volume within the volume just created dismount the drive and carry out the normal procedure for creating a hidden volume see the Advanced Topics section for instructions on how to do this 78 11 Miscellaneous Notes Please do read the documentation the FAQ section in particular before emailing questions The FAQ section in particular may well have the answer you re looking for Both the PC and PDA versions of FreeOTFE and FreeOTFE Explorer are fully compatible with one another From the main window doubleclicking on a mounted drive will launch explorer on that drive Rightclicking brings up a context menu After creating a new FreeOTFE volume it is recommended that you make a backup of the volume s CDB In the case of volume files which have their CDB stored as part of the volume file this can be achieved by selecting Tools Critical data block Backup In the case of volume files where the CDB is stored in a separate keyfile simply make a backup copy of this keyfile A number of FreeOTFE volume properties can be changed via the Tools Change volume keyfile password details menuitem Note that volumes must be dismounted first be
166. ld like to create a hidden volume Disk partition to create encrypted volume on Disk 0 Disk 1 Doubleclick partition to display properties _ Entire disk C Create hidden volume within selected partition Cancel New volume wizard showing full partition information Therefore it is recommended that you create any new partition based volumes while logged in as an administrator To do this under Windows Vista you will need to run FreeOTFE with elevated permissions locate the FreeOTFE exe executable where you installed it rightclick on this executable and select Run as administrator from the context menu 5 2 2 Special Note for Windows Vista x64 64 bit and Windows 7 64 bit Users In order to format a new partition or disk based volume under Windows Vista x64 64 bit the volume must be mounted while FreeOTFE is running with elevated permissions To do this 1 Locate FreeOTFE exe where you installed it rightclick on this executable and select Run as administrator from the context menu 2 Mount the partition disk as normal 3 Format the mounted volume This procedure only needs to be carried out once in order to format the volume it may subsequently be mounted and used by any user 23 Elevated permissions are not required to format file based volumes 5 3 Creating Hidden Volumes FreeOTFE offers users the ability to create hidden volumes stored inside other host volumes To create a hid
167. le cause for this is that you were creating a volume file on a FAT FAT32 filesystem however FAT FAT32 filesystems cannot support files larger than 4 GB 1 byte See the FAQ What is the largest volume that I can create for further information and how to resolve this Q What is the largest volume that I can create A On a PC FreeOTFE has a theoretical maximum volume size of 2 64 bytes 16777216 TB 17179869184 GB For fairly obvious reasons I have not had the opportunity to test a volume this size 91 In practice however although partition based volumes may be able to realise volumes as large as this file based volumes may find that limitations with the filesystem that the volume file is to be stored upon may prevent this limit from being reached For example a FAT32 drive cannot store a volume file which is 4GB or larger In practical terms this means that the largest volume you can create on a FAT32 filesystem is 3999 MB An NTFS formatted drive can store volume files much larger in excess of FAT32 s 4GB limit and up to FreeOTFE s maximum size stated above On a PDA the largest volume supported is 232 4GB This is due to limitations with Windows Mobile Q Help I forgot my password I know it was something like A Oops That was silly of you wasn t it If you ve secured your volume with something like AES then you can pretty much kiss goodbye to your data If you know what most of your password i
168. les BINARY_OO_FF_RPTD dat test_mountpoint umount test_mountpoint losetup d dev loop1 cryptsetup luks luksClose myMapper losetup d dev loop0 rm rf test_mountpoint 74 Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the losetup volume file 3 In the dialog shown enter password1234567890ABC as the key and set any of the options wanted 4 Click the OK button 75 10 Plausible Deniability 10 1 Overview The subject of plausible deniability and OTFE systems is a lot more involved than do my volume files have any kind of identifying signature Plausible deniability in OTFE systems is largely based on the theory that you can claim that your volume files are not encrypted data you don t know what they are you can t be expected to know every operation that your OS carries out Perhaps it s some corrupt data that the system recovered at some stage This claim is only possible with OTFE systems which do not embed any kind of signature into their encrypted data typically an unencrypted critical data area FreeOTFE volume files have no such signature However this simplistic approach to plausible deniability has many drawbacks and is highly unlikely to offer any significant form of protection for example 1 Encrypted data has relatively high entropy something corrupt files recovered automatically by the OS are not likely to have Recovered data is likely to hav
169. ll tokens found on your system showing the slot number the token is inserted in and the token s label If you have not yet inserted your token do so and click Refresh to refresh the list 38 If only one token is found it will be selected automatically and the token selection control will be disabled Otherwise select the token you wish to use enter your PIN and click OK to continue 7 4 1 Secure authentication path If your token hardware features a secure authentication path e g a smartcard reader with PIN entry keypad you can take advantage of it by selecting the Use secure authentication path checkbox when FreeOTFE prompts for the token s PIN 39 8 Command Line Interface Both the PC and PDA version support passing parameters via a command line interface 8 1 PC Version 8 1 1 Synopsis FreeOTFE exe mount volume lt volume gt freeotfe linux readonly drive lt drive letter gt offset lt offset gt nocdbatoffset keyfile lt keyfile gt keyfileisascii keyfilenewline CRLF LF CR lesfile lt LES file gt saltlength lt saltlength gt keyiterations lt keyiterations gt password lt password gt silent noexit minimize settings lt settings file gt FreeOTFE exe dismount lt drive letter gt all force FreeOTFE exe count FreeOTFE exe create FreeOTFE exe portable start on 1 stop off 0 toggle silent FreeOTFE exe drivercontrol
170. lling all queued requests to the driver Improved progress dialog s responsiveness when overwriting free space preventing it from appearing frozen and giving user a better indication of progress O Fixed minor cosmetic fault on the keyfile creation dialog O FreeOTFE volume creation wizard now gives user more flexibility to specify the sector IV generation method used Added support for Linux dm crypt volumes e g ESSIV 168 O O Added progress dialog when creating volume files Message shown when FreeOTFE exits and stops portable mode no longer displayed unless there was a problem stopping portable mode v00 50 00 BETA 1 4th April 2005 O oo0o0o0o 0 O O Implementation of portable mode Added support for keyfiles User passwords are no longer displayed they are blanked out with characters Added option to backup and restore the CDB from volumes with a CDB Added option to dump critical data block to a human readable file Driver control dialog now indicates state of drivers making it a lot clearer what s happening Added support for encrypted partitions User can now change their passwords and many other FreeOTFE volume properties When volume files are mounted and used their timestamps created last accessed and last modified and attributes are recorded They are then reset on dismount Volume file timestamps and attributes are reset after dismounting improving plausible deniability Added ability to
171. local computer policy 1 Select Local Computer Policy Computer Configuration Administrative Template System Double click the Turn off Autoplay entry Change the Not configured Enabled Disabled selection to any of the three options Click Apply Change the Not configured Enabled Disabled selection to either Not configured or Disabled 6 Click Apply 5 Reset the setting for users 1 Select User Configuration Computer Configuration Administrative Template System Double click the Turn off Autoplay entry Change the Not configured Enabled Disabled selection to any of the three options Click Apply Change the Not configured Enabled Disabled selection to either Not configured or Disabled 6 Click Apply nA BW hd nA BW bd 107 See also Enable Autorun on DVD CD and other removable media Q Can I use FreeOTFE with MojoPac A Yes There are two basic ways of encrypting you data using FreeOTFE while using MojoPac 1 By creating an encrypted volume and installing MojoPac onto it 2 By installing MojoPac as normal e g onto a USB drive and running FreeOTFE from within MojoPac Method one Installing onto a FreeOTFE volume The first method is probably the more secure as your entire MojoPac setup is encrypted Simply create a new FreeOTFE volume on your USB drive mount it and then install MojoPac onto the mounted volume In this way everything relating to yo
172. longer exists LUNA cryst201 dll WWW site no longer exists Dallas Semiconductors iButton dspkcs dll 178 hardware cryptoki dll Full path to library may be required e g C Program Files ERACOM Cprov SDK bin csa cryptoki dll On 1st December2005 Eracom Technologies AG was acquired by SafeNet software emulation cryptoki dll Full path to library may be required e g C Program Files ERACOM Cprov SDK bin sw cryptoki dll On 1st December2005 Eracom Technologies AG was acquired by SafeNet Estonian Government Estonian Electronic Identity eID Card opensc pkcs11 dll Eutron Crypto Identity sadaptor dll Feitain technologys Co Ltd ePass 1000 EP1PK111 DLL ePass 2000 ep2pk11 dll ePass 2000_FT11 ngpllv211 dll Confirmed working with FreeOTFE ePass 3000 ngpl1v211 dll ePass 3003 ShuttleCsp11_3003 dll Confirmed working with FreeOTFE Gemplus gclib dll pk2priv dll GemPlus GemSoft GemPlus GemSoft Smartcard w32pk2ig dll GemSafe gclib dll GemSafe new version pk2priv dll 179 GemSafe old version IBM 4758 cryptoki dll IBM Digital Signature for the Internet DSI for MFC cards CecSigIT dll IBM Embededded Security Subsystem csspkes11 dll IBM Netfinity PSG Chip1 ibmpkcss dll IBM SecureWay Smartcard w32p
173. lopment of FreeOTFE Explorer To build the command line decryption utilities the following software is required A C compiler Visual C NET was used to write and test this software Please follow the following steps 154 1 Install and configure up the build environment as described as per building the backend drivers you may omit the SDK and DDK 2 Modify the software as appropriate for your test Please see the command line decryption utility documentation 3 Launch the relevant my_build_exe bat file The executable should be built in the same directory 13 9 5 Signing the Binaries To sign the FreeOTFE binary files exe dll and sys files the procedure is pretty much as described at Pantaray Research WWW site At present FreeOTFE is signed using a self signed certificate the full procedure used is as follows 1 Install Visual Studio 2 From a command prompt run vevarsall all commands detailed below should be executed from this command prompt Create a private certificate makecert exe sv sdeanl2 pvk n E sdeanl2 sdeanl2 org CN Sarah Dean sdeanl2 cer this should create two files sdean12 pvk and sdean12 cer Create a test software publisher certificate SPC cert2spc exe sdeanl2 cer sdeanl2 spc to create sdean12 spc This file would normally be supplied by a CA if purchased Create a personal information file pvk2pfx pvk sdeanl2 pvk spc sdeanl2 spc pfx sdeanl2
174. lumes greater than 4GB Corrected estimated time remaining shown on progress dialog Hotkey options now saved correctly Minor cosmetic improvements 00 26th June 2008 Added support for 64 bit versions of MS Windows Added support for PKCS 11 Cryptoki security tokens smartcards Significantly improved partition selection system Added drive keyfile and lesfile command line parameters when mounting volumes Added user configurable global setting for default drive letter Extensive additions changes and improvements made to documentation Various cosmetic and usability improvements v3 00 16th December 2007 165 O00 0 O O O O FreeOTFE is now available both as a full installation package as well as standard ZIP version Added LRW and XTS cypher mode support Added post mount pre dismount post dismount autorun option to allow automated integrity checking cleanup etc Added option to explore drive automatically after mounting Made volume file timestamp reversion optional i e the timestamps on volume files are automatically set back to their pre mount values on dismounting previously it would always do this Simplified password entry for mounting FreeOTFE volumes advanced options can easily be displayed by clicking button Advanced mount options can be displayed by default by setting relevant option Password entry dialog is now only dismissed when the volume is successfully mounted or the user cancels the mo
175. mand line FreeOTFE will terminate with one of the following exit codes Exit code Meaning 0 Success Invalid unrecognised command line n a Unable to mount volume Unable to dismount volume n a n a 8 2 5 Examples Mounting a FreeOTFE volume FreeOTFE4PDA exe mount volume Storage Card my encrypted volume dat Dismount volume mounted at FreeOTFE secure FreeOTFE4PDA exe dismount FreeOTFE secure Dismount all volumes emergency FreeOTFE4PDA exe dismount all force 46 9 Linux Volumes j A This section applies to the PC version of FreeOTFE only UZS IMPORTANT This is obvious but If you are using FTP to transfer your Linux volumes between your Linux and MS Windows systems make sure you transfer the volume file in binary mode 9 1 Creating Linux Volumes IMPORTANT If you select the wrong options when creating a Linux volume using FreeOTFE you will not be able to read it under Linux Although this is patently obvious there are some people who NOTE At time of writing 17th July 2005 although FreeOTFE can read and write LUKS volumes it cannot create them itself To create a new encrypted Linux compatible volume 1 Launch FreeOTFE 2 If you are creating a file based volume as opposed to an encrypted partition 1 Select File Linux volume New 2 Enter the filename and size of the volume required 3 Click the OK button This will
176. mounted and shown in the main FreeOTFE window To reduce the time taken FreeOTFE spends mounting volumes see the FAQ How can I speed FreeOTFE up when mounting my volumes If this is the first time you have mounted a particular volume after creating it you will need to format the virtual drive before it can be used To do so select the mounted volume shown in the main FreeOTFE window and select the Tools Format menuitem The standard MS Windows format utility will be displayed and should be used to carry out the format If you wish to use your volume on both PCs and PDAs or with FreeOTFE Explorer it should be formatted on a PC as either FAT or FAT32 see also the FAQ on PDA formatting To increase security it is recommended that after a volume is formatted it is overwritten with random data However this process can take some time SECURITY and may be skipped if required See section on plausible deniability for further details Once mounted a virtual drive can be used in the same way as any other drive e g they will appear in Windows Explorer and in Open Save dialogs shown by applications transparently encrypting and decrypting your files as and when needed File Edit view Favorites Tools Help File Explorer 3 4 11 01 X E i Search E My Device Name v E Application D Address W My Computer E ConnMg Folders x Name BP Desktop _ Files 4 My Documents
177. n to volumes by using the token to encrypt the volume s CDB and or keyfile s The keys secret keys used for this encryption are automatically generated by a token and can never be duplicated extracted or in any way copied from the token even if the token s PIN is known All encryption decryption operations used to secure a keyfile volume CDB are carried out by the token itself This mechanism therefore provides a means of tying a volume keyfile to a physical token preventing it from being mounted unless the token is present and its PIN is known It should be noted however that since it is inherent that no backups of the secret keys stored on a token can be made the loss of the token will result in the loss of all data stored on the volume it protects unless a separate means of accessing the volume e g a keyfile which isn t secured by the same PKCS 11 token is available 7 3 1 Usage To encrypt a volume s CDB keyfile 1 Plug in insert your token 2 Go to Tools PKCS 11 Token management 3 Enter your token s PIN and click OK 4 The token management dialog should be displayed select the Secret keys tab 5 Click New 6 Enter a meaningful name of the token and select the cypher to be used for the encryption It should be noted that the range of cyphers available for use is determined by the capabilities of 37 your token and not FreeOTFE Click OK and the new key will be created Select the
178. nctions In order to allow the above WXP builds to work under Windows 2000 IFSRelated h includes a copy of these macros and uses them regardless see comments in code for an explanation 13 9 2 FreeOTFE4PDA To build FreeOTFE4PDA both the drivers and GUI 1 Open FreeOTFE4PDA sIn using Visual C 2 Set the build configuration within Visual C to Release Pocket PC 2003 ARM4 3 Rightclick on each project in turn and select Rebuild A copy of the binary which is built will be copied into the directory above your src directory 13 9 3 FreeOTFE Explorer 13 9 3 1 Building the GUI This is a description for Delphi newbies of the basic steps involved in compiling the FreeOTFE Explorer GUI 153 To build the GUI the following software is required Delphi CodeGear Delphi 2007 or later though Delphi 2006 should just as well Delphi v5 v7 can probably be used with minimal changes though wouldn t look as nice under Windows Vista The SDeanComponents package v2 00 00 or later Optional GNU gettext for Delphi dxgettext available free from http dybdahl dk dxgettext This package adds support for language translations The binary release of this software was built with CodeGear Delphi 2007 1 With each of the packages in the SDeanComponents archive 1 Build each package 2 Install each package 3 Ensure that the correct path to each package is added to your Delphi environment Tools Environmen
179. ndows Vista itself which is generating these prompts and not FreeOTFE which will have no access to the password you type in The same type of warning dialogs will appear when you attempt to for example change the system time or dete by going to Window s Control Panel selecting Date and Time and then changing the computer s time date If you are happy for FreeOTFE to carry out the operation you requested of it you should select the relevant option from the consent credential dialog to allow FreeOTFE to proceed You can find out more about UAC from the 11 2 PDA Version M This section applies to the PDA version of FreeOTFE only If you intend using your encrypted volumes with both PDAs and PCs please ensure that you initially create and format them using the PC version to ensure that they can be read by either system If a volume is created on a PDA your PDA will format it in a slightly different manner i e it will be include additional unused information at the start of the partition which will prevent your PC from reading it correctly even though it works correctly with a PDA Volume files created on a PC can be used freely with both PDAs and PCs When mounting a volume under the PDA version if you have more than one cypher hash driver combination which can be used to decrypt the volume in question the first valid combination will be used This is unlike the PC version which will prompt you to select which combination y
180. ng anything For safety reasons FreeOTFE only writes the initial 512 byte CDB to the start of the disk partition when creating a new disk partition based volume see the Plausible Deniability section for how to initialize a volume by overwriting it If you haven t yet mounted the volume and started writing data to it or overwriting it you have a good chance of getting your files back Obviously if you have written data to the encrypted volume e g by selecting one of the overwrite options or copying files to it the amount you will be able to recover will decrease The recommended approach to recovering the data originally stored on the disk partition is to 1 Dismount all mounted volumes 2 Take an image of the disk partition the volume was created on e g by using a tool such as USB or any disk imaging cloning tool 3 Use any standard recovery software e g Restorer 2000 Pro on the image taken not the disk partition itself to try to recover your data Q Does FreeOTFE offer whole disk encryption A Yes FreeOTFE does support whole disk encryption although it does not yet support encrypting the system partition i e the entire disk or partition that the OS boots from To encrypt a whole disk proceed as though creating an encrypted partition and select the entire disk checkbox after selecting the drive to be used 112 Q Do I have to use a security token smartcard with FreeOTFE A No FreeOTFE offers se
181. nonstandard Tiger and Whirlpool hashes when using LUKS volumes Removed redundant warning about drivers not being started in portable mode when they had been manually installed Corrected minor cosmetic issue with status bar display Added OS version ID to human readable CDB dumps Moved weaker drivers FreeOTFE4PDAHashNull dll FreeOTFE4PDACypherNull dll and FreeOTFE4PDACypherXOR dll into a weak drivers directory most users shouldn t use these drivers but they re still included in the release if needed v1 60 00 28th January 2006 O O O Added the following cyphers CAST6 Gladman library Fixed minor bug that prevented FreeOTFE from properly dismounting volumes under certain conditions Corrected build error that prevented previous version from operating correctly under MS Windows 2000 v1 50 00 8th January 2006 O O oo0o0o 0 O Changed email address from sdean12 softhome net to finally sdean12 sdean12 org Added the following cyphers Serpent AES Gladman library RC 6 Gladman library Twofish Gladman library e MARS Gladman library source only pending licence clarification Updated to allow volumes to be mounted across networks Added ability to resize the driver control dialog Corrected fault that prevented LUKS partitions from being mounted Added support for LUKS volumes which use ESSIV subject to the hashlength of the ESSIV hash generating the same number or less bits as the c
182. nted the user must specify the correct salt length unless using a keyfile in which case the keyfiles salt length must be specified by using the Advanced options available on the FreeOTFE password entry dialog The default salt length is 256 bits Any salt length entered must be a multiple of 8 bits 5 4 3 Drive Letter PC version only By default FreeOTFE will use the next available drive letter when mounting a volume This behaviour can be changed to use a specific drive letter on a volume by volume basis by setting it on this option The default setting here is Use default use the next available drive letter Note If the chosen drive letter is in use at the time of mounting the next free drive letter will be used 5 4 4 CDB Location Normally a volume s CDB will be stored as the first 512 bytes of the volume However this does increase the size of the volume by the size of the CDB which can FreeOTFE volumes more distinctive and making it slightly more obvious that a volume file is volume file This is most clearly shown when creating a file based volume a 2GB volume for example will be 2 147 484 160 bytes in length made up of a 2 147 483 648 byte 2GB encrypted disk image plus a 512 byte embedded CDB To reduce this it is possible to create a volume without an embedded CDB the CDB begin stored in a separate file as a standard FreeOTFE keyfile In this case a 2GB volume would comprise of a 2 147 483 648 by
183. nux volume If a volume type FreeOTFE Linux isn t specified the user will be prompted for this information mount Mount indicated file partition minimize Minimize main window when run nocdbatoffset Indicates there is no CDB stored from the offset specified by offset Only meaningful when both offset freeotfe and keyfile are used noexit Normally when run with command line parameters FreeOTFE carries out the requested action and exits Specifying this parameter will cause FreeOTFE to continue running offset lt offset gt Use specified offset when mounting This may be specified using GB MB KB units or with no units for an offset in bytes e g SGB or 5368709120 for a 5GB offset Note If the value used for the offset has has a space in it it should be surrounded by quotes e g 10 GB or 10GB are both valid password lt password gt The password to be used It is not recommended that this is used particularly in shortcuts as this would involve storing your password in plaintext such that anyone can read it portable start on 1 stop off 0 toggle Turn on off portable mode readonly Mount the volume readonly settings Use specified file for program settings instead of normal settings location silent 42 Can be used when installing uninstalling drivers and changing portable mode to suppress dialogs and
184. ocessed in the same manner 5 After all possible hash cypher combinations have been exhausted e If no cypher hash combination successfully decrypted the Volume details block the user will be informed that they have entered incorrect details If more than one cypher hash combination successfully decrypted the Volume details block the user should be prompted to choose which of the combinations they wish to use The system will proceed as if only the user selected combination had been successful in decrypting If exactly one cypher hash combination successfully decrypted the Volume details block then the Encrypted partition image will be decrypted as necessary using this cypher hash combination together with the information obtained from the decrypted Volume details block As a result of the volume s layout it is not necessary to store the cypher or hash algorithm used for en decryption anywhere Nor is it necessary to prompt the user for this information since during mounting a FreeOTFE formatted volume this information can be determined dynamically by attempting the mount using all possible combinations of installed hash cypher in conjunction with the check hash 13 2 2 CDB Format ID 2 NOTE This CDB layout is obsolete all new volumes should use the latest CDB format 131 13 2 2 1 Overview A FreeOTFE critical data block consists of CDL bits of data The following table describes the high level layout of a FreeOTF
185. ocksize we will use amp bits 1 byte as bs 1 The Encrypted block is extracted from the critical data block The length of the Encrypted block is calculated as 130 4096 sl bs bs Alternatively the length of Random padding 1 can be viewed as being 4096 sl bs Where represents the modulus and integer division 2 The Encrypted block is decrypted using 1 The first ks bits of the hash value previously generated as the decryption key if hk is less than ks then the hash will have extra zero bits appended to it in order to pad it out to ks 2 An IV consisting of a block of bs bits all set to 0 3 Next the Check hash and Volume details block are extracted from the decrypted data In order to do this the length of the check hash must be known if the hash algorithm used on the salted user s password is reported to generate hashes 1 bits long then the check hash is assumed to be 512 bits long Otherwise the actual hash length is used 4 The Volume details block is hashed and right padded with zero bits to make it the same length as the Check hash which it is then compared with If the hash generated matches the Check hash then the Encrypted block is deemed to have been successfully decrypted a note will be made of the cypher and hash used together with the contents of the decrypted Volume details block In either case all remaining hash cypher combinations will be pr
186. ode as the build process requires that certain 152 files are copied over into the FreeOTFE src directories Annoying but this is a requirement of the MS build exe command The LibTomCrypt source in particular had minor configuration changes to tomcrypt_cfg h and tomcrypt_custom h please compare the original source a copy of its release ZIP file is stored under src 3rd_party libtomcrypt with the modified version uncompressed in a directory under this one 13 9 1 2 2 Building the FreeOTFE Drivers Either 1 Open FreeOTFE sIn using Visual C 2 Rightclick on each project in turn and select Build or 1 Enter each of the separate driver directories in turn and launch each project s my_build_sys bat In either case a copy of the binary which is built will be copied into the directory above your src directory After reaching this stage you should have successfully built your own version of the FreeOTFE drivers Notes 1 If FREEOTFE_TARGET is set to W2K the resulting binary may not operate correctly under MS Windows XP as a number of functions what are only needed under Windows XP and later are ifdef d out As a result a W2K binary may not operate correctly under Windows XP e g trying to format a volume may result in Nothing happening If you want a binary which will operate under both Windows 2000 and Windows XP set this to WXP 2 Windows XP migrated a couple of the previous Windows 2000 macros to be fu
187. og when mounting FreeOTFE volumes A list of driver library names supplied by common manufacturers may be found at Appendix E PKCS 11 Driver Libraries 7 2 Secure Keyfile Store Keyfiles may be stored on tokens in a similar fashion to which they can be stored on for example a USB flash drive However unlike storing a keyfile on a USB flash drive those stored on a token require the token s PIN to be entered before they can be accessed 7 2 1 Usage To add a keyfile to your token 36 Create a keyfile for your volume as per normal Plug in insert your token Go to Tools PKCS 11 Token management Enter your token s PIN and click OK The token management dialog should be displayed select the Keyfiles tab Click Import Select the keyfile previously created and click OK NYDN PWN To use a keyfile stored on a token 1 Follow the normal procedure for mounting your FreeOTFE volume 2 When shown the password prompt select PKCS 11 as the keyfile option you will then be prompted to authenticate yourself to the token Enter your token s PIN and click OK 4 Select the keyfile stored on your token and proceed as normal by entering your keyfile s password etc and clicking OK to mount W Note More than one keyfile can be stored on a single token however they must all have different names 7 3 Token Encryption PKCS 11 tokens can also be used to add a further level of encryptio
188. ollowed immediately by the tweak key An XTS encrypted volume s Master key will be the two XTS encryption keys one after the other In all cases the Master key length will indicate the total length of all keys It is the responsibility of the cypher driver to determine how the key material is used FreeOTFE v3 0 and later and FreeOTFE4PDA v3 0 and later create volumes using this layout 142 13 3 Creating FreeOTFE Volumes To create a FreeOTFE volume file a fairly significant amount of information is required due to freedom that FreeOTFE gives you in creating volume files Broadly speaking creating a FreeOTFE volume consists of three distinct stages 1 Creating a file large enough on the local filesystem to store the encrypted partition image and CDB if included as part of the volume 2 Writing a CDB either to the volume file or a separate keyfile depending on the user s choice 3 Mounting the volume formatting it and shredding overwriting all free space Stage 1 is straightforward write data to the file until is has gained the required size This stage is skipped in the case of creating a hidden volume or volume based on a partition Stage 2 is more complex and is described below Stage 3 is required in set the volume up for use and increase security This is largely a manual process carried out by the user depending on their needs 13 3 1 Writing the CDB keyfile The following procedure is used to
189. ons and uncheck the Support WM 5 0 soft keys option See also FAQ What does the Support WM 5 0 soft keys option do Q I don t like the multi item menubar toolbar at the bottom of FreeOTFE4PDA s display how do I get it to use the newer two item style softkey menus instead A The two item menu at the bottom of the display is the Microsoft standard for Windows Mobile 5 and later applications and is designed to allow users with softkeys i e smartphones with two buttons left and right below their display to navigate more quickly and easily 120 If you have a PDA which runs Windows Mobile 2003 second edition or earlier your PDA does not support this new style menu However if you are running Windows Mobile 2005 or later you can enable the two item style menu by simply tapping Menu View Options and making sure the Support WM 5 0 soft keys option is checked See also FAQ What does the Support WM 5 0 soft keys option do Q Can I use my PC volumes with the PDA version A Yes See FAQ Can I use the same encrypted volumes on both my PC and PDA Q I upgraded to the lastest version of FreeOTFE4PDA can I still mount my old volumes A Yes you can It should be noted that v3 75 and later only have the SHA hash and AES cypher drivers enabled by default If your volume was secured using a different hash cypher algorithm please enable the required drivers by following the procedure described in
190. ormation about the various disk partitions When this happens FreeOTFE will fallback to displaying a more restricted set of information e g no partition sizes Because more information can be displayed if the user is an administrator or under Windows Vista the FreeOTFE process has been started with escalated under UAC it is highly recommended that any partition based volumes are created when logged in as an administrator Under Vista FreeOTFE should be launched by rightclicking on the executable FreeOTFE exe and selecting Run as administrator By displaying additional information there is less likelihood of creating a volume on the wrong partition Select Partition Please select from the following disks partitions Disk 0 Disk 1 Doubleclick partition to display properties C Show CD DVD drives C Entire disk Cancel Partition selection dialog full information shown 111 Select Partition Please select from the following disks partitions Disk 0 Disk 1 C Show CD DVD drives _ Entire disk Cancel Partition selection dialog restricted information shown Q I accidentally selected the wrong disk partition when creating a new volume and now can t see my files How can I get my data back A The more important thing to do in this kind of situation is STOP and THINK Before attempting any kind of recovery understand what you are going to do and how you are going to do it before doi
191. ory in which you installed the MS SDK C AMSSDK MSDDK_DIR The directory in which you installed the MS DDK C WINDDK 3790 2 Edit setup_env_driver bat in the same directory and ensure that SETENV BAT is called with the parameters appropriate to the type of build you wish to create and that FREEOTFE_OUTPUT_DIR is set to the appropriate directory under the source directories where the build executable places the files it creates this shouldn t be needed as it will happen automatically if the above are configured correctly 13 9 1 2 1 3 3rd Party Source Code Some of the FreeOTFE drivers the hash encryptions drivers in particular are dependant on certain 3rd party software being installed FreeOTFE s source code comes complete with 3rd party included in the src 3rd_party directory and should be preconfigured ready for use Alternatively you may wish to download this 3rd party source from the original authors in order to verify the integrity of this software For this reason details of where this software was obtained from are included in the above directory Please note that should choose the latter option it is important that you review the individual driver notes see separate driver directories _notes txt files to ensure that this software is configured correctly Additionally you may well have to modify the my_build_sys bat files directing them to the location where you installed said 3rd party source c
192. ou are having problems with the PDA version of FreeOTFE please could you also include 1 The make and model of device you are using 2 The exact version number of your OS which can be found by 1 Tapping the Start button at the top left of your screen 2 Tapping Settings 3 Tapping on the System tab of the dialog displayed 4 Tapping on the About icon this will give full details of your OS version e g v5 1 1702 Build 14366 1 0 1 161 16 TODO List Additional hash and cypher drivers suggestions welcome GPG integration support for using GPG to generate random data and Linux AES multikey support this only really need the GPG interface finishing off Support for Linux key iterations C option Other MAC algorithms e g PMAC OMAC Command line utility written in C to carry out the main functions of the GUI The source code could do with a little tidying up Constructive suggestions welcome 162 17 Appendix A Version History 17 1 PC Version v5 21 7th February 2010 O O O Added Russian language translation Added translator credit to About dialog Minor tweaks to portableapps com launcher v5 20 3rd January 2010 O O O O O Added support for using keyfiles with LUKS volumes Hint For ease of use keyfiles may also be dragged and dropped onto the LUKS password entry dialog Changed disk partition selection dialog to treat doubleclicking on a disk partition as selecting i
193. ou wish to use If you wish the PDA version to use a specific cypher hash driver implementation when mounting volumes please remove all other cypher hash drivers which implement the same cypher hash See FAQ relating to duplicate drivers To reduce the time taken for FreeOTFE4PDA to mount volumes please see the FAQ How can I speed FreeOTFE up when mounting my volumes To reduce the amount of storage space FreeOTFE4PDA takes up on your PDA i e its installed footprint please see the FAQ How can I reduce the amount of storage space FreeOTFE4PDA takes up when installed 81 12 FAQ The latest version of this FAQ along with the latest FreeOTFE user manual can be found online at the FreeOTFE WWW site 12 1 FAQ Contents 12 1 1 General Whare are the differences between FreeOTFE and FreeOTFE Explorer How can I help the FreeOTFE project Which of the hash cypher algorithms should I use Which of the random number generators RNGs should I use Is FreeOTFE based on CrossCrypt Is FreeOTFE based on Linux s losetup Right now FreeOTFE supports losetup volumes do you have any plans to include support for DriveCrypt BestCrypt etc volumes When I mount a FAT FAT32 formatted Linux volume under FreeOTFE everything works perfectly When I do the same with myext2 ext3 RiserFS etc volume I can t see my files Why do the Linux examples for LUKS dm crypt volumes show losetup being used twice FreeOTFE comes with a se
194. ountpoint cp test_files BINARY_ABC_RPTD dat test_mountpoint cp test_files BINARY_0OO_FF_RPTD dat test_mountpoint umount test_mountpoint losetup d dev loopl cryptsetup remove myMapper losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume file 3 Key tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the RIPEMD 160 160 512 hash Ensure Hash with A s if hash output is too short is checked Leave iteration count at 0 4 Encryption tab Select the AES CBC 256 128 cypher Select ESSIV as the IV generation method Set Sector zero location to Start of encrypted data Select SHA 256 256 512 as the IV hash Select AES CBC 256 128 as the IV cypher 5 File options tab Leave offset at 0 Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button 9 9 6 Example 4 Volume Encrypted Using 448 bit Blowfish This example demonstrates use of a dm crypt Blowfish 448 volume Creating the volume file under Linux dd if dev zero of volumes vol_blowfish_448 vol bs 1K count 100 losetup dev loop0 volumes vol_blowfish_448 vol echo password1234567890ABC cryptsetup c blowfish s 448 create myMapper dev loop0 dmsetup 1s dmsetup table dmsetup status losetup
195. p User guide will take you to the online version if a local copy cannot be found It is recommended that you keep a copy somewhere though on your desktop PC if nowhere else You can further reduce the amount of storage taken up by deleting any unused cypher and hash drivers this will also increase the speed at which FreeOTFE4PDA will mount volumes See FAQ How can I speed FreeOTFE up when mounting my volumes for further details on how to do this If you don t need any of the language translations or only one of them deleting those translations you don t need from the locale subdirectory can free off a small amount more storage Q Why do I get the message Unable to locate local copy of user guide would you like to see the latest version on the Internet when I try to view the user guide by selecting Help User guide 118 A FreeOTFE4PDA attempts to locate a local copy of the user guide stored with the executable If this is not found it will fallback to trying to show you the latest version found on the FreeOTFE WWW Site To prevent this please place a copy of the docs directory included with the release into the same directory as your FreeOTFE4PDA exe executable i e Such that you have a docs subdirectory in the same directory as the FreeOTFE4PDA exe executable on your PDA Q When I try to mount a volume I sometimes the error Mount failed the virtual storage device could not be activated
196. p test_files BINARY_OO_FF_RPTD dat test_mountpoint umount test_mountpoint losetup d dev loop1 cryptsetup remove myMapper losetup d dev loop0 rm rf test_mountpoint 69 Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume file 3 Key tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the SHA 512 512 1024 hash Ensure Hash with A s if hash output is too short is checked Leave iteration count at 0 4 Encryption tab Select the AES 256 bit XTS cypher Select Null IV as the IV generation method 5 File options tab Leave offset at 0 Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button 9 10 Examples LUKS This section gives a series of examples of how to create Linux LUKS volumes and then mount them using FreeOTFE These examples have been tested using Fedora Core 3 with a v2 6 20 1 kernel installed and using cryptsetup luks v1 0 though they should work for all compatible Linux distributions Note The executable name in the following examples is cryptsetup luks most systems use cryptsetup 9 10 1 Initial Setup To begin using LUKS under Linux ensure that the various kernel modules are installed modprobe cryptoloop modprobe aes modprobe anubis modprobe arc4 modprobe blkcipher modprob
197. pfx f pi lt pvk password gt po lt pfx password gt Where lt pvk password gt is the password used when generating the pvk file with makecert txt lt pfx password gt is the password you wish to use for securing the new pfx file Sign each of binary files signtool exe sign f sdeanl2 pfx p lt pfx password gt v t http timestamp verisign com scripts timstamp dll lt filename gt Where lt pfx password gt is the password used when generating the pfx file with pvk2pfx The URL specified is a time stamping service Verisign s in this case 13 9 6 Additional Notes When building the C code FreeOTFEPlatform h automatically defines one of the following FreeOTFE_PC_DRIVER FreeOTFE_PC_DLL FreeOTFE_PDA 155 depending on what is being built This header file should be included at the start of every file which uses any of these defines Yes this is obvious but easily overlooked 13 10 Creating a New Hash Cypher Driver These instructions specify in general terms the steps in taking an existing cypher driver Blowfish in this case and modifying it to create a new cypher driver The procedure for creating a new hash driver is practically identical but one of the existing hash drivers should be used as a base instead of the Blowfish cypher 1 Create a new directory to contain your new cypher driver Make a copy of the directory containing the Blowfish cypher driver CYPHER_BLOWFISH
198. port other filesystems such as ext2 87 As a result in order to read write to your encrypted Linux volumes under MS Windows you will need to either 1 Format the volume under Linux using one of the filesystems MS Windows understands e g FAT or 2 Install 3rd party software on your MS Windows system which provides the filesystem e g ext2 that you wish to use Q Why do the Linux examples for LUKS dm crypt volumes show losetup being used twice A This actually has nothing to do with FreeOTFE but appears to be an oddity with mkdosfs dm crypt Although this section of the documentation shows losetup dev loop1 dev mapper myMappermkdosfs dev loopl you should be able to simply use mkdosfs dev mapper myMapper However when this section of the documentation was written and tested under Fedora Core 3 with a v2 6 11 7 kernel installed and using cryptsetup luks v1 0 this shorter and more sensible version resulted in mkdosfs generating the following error mkdosfs dev mapper myMappermkdosfs 2 8 28 Feb 2001 mkdosfs unable to get drive geometry for dev mapper myMapper YMMV though you may well find that formatting the volume with a different filesystem will remove the double loop issue Please note though that if you are intending to encrypted volumes which don t use FAT NTFS under MS Windows you will need a suitable filesystem driver Q FreeOTFE comes with a set of command line decryption u
199. pted partition image that I added support for them into FreeOTFE Having said that the format of losetup volumes are simple have you any idea how many different options combinations etc it has Each option on its own may be relatively simple but there are a fair number of them See the relative complexity of the FreeOTFE s Linux mount dialog you have to tell it everything Q Right now FreeOTFE supports losetup volumes do you have any plans to include support for DriveCrypt BestCrypt etc volumes A This is unlikely to happen as there is no standard for OTFE volume files each system uses its own layout Since adding support for other OTFE systems is non trivial and few OTFE systems have released proper technical documentation into the public domain it may be awhile before such support is added Q When I mount a FAT FAT32 formatted Linux volume under FreeOTFE everything works perfectly When I do the same with my ext2 ext3 RiserFS etc volume I can t see my files A FreeOTFE does one thing when a volume file is mounted FreeOTFE presents a new storage device to the operating system Like all OTFE systems it has no comprehension at all of what FAT FAT32 NTFES let alone ext2 ext3 etc this understanding lies well outside the scope of an OTFE system and is the responsibility of the filesystem drivers installed Although MS Windows does come with filesystem drivers for FAT FAT32 NTES it does not natively sup
200. r Windows Mobile 5 and later applications and is designed to allow users with softkeys i e smartphones with two buttons left and right below their display to navigate more quickly and easily Alternatively you can still opt to use the older menu and toolbar style used with Windows Mobile 2003 second edition and earlier Here is a sample of what the different menus look like 119 Menu and toolbar style menus WM 5 0 soft key menus O File iew Tools Help GQ Mount ee Menu View gt Tools gt Help gt Exit iew Tools Help D fa ET E You can change this setting by going to Tools Options If you have a PDA which runs Windows Mobile 2003 second edition or earlier your PDA does not support this new style menu Q I don t like the new two item menus at the bottom of my display how do I change them back to the older toolbar style menu A The Microsoft standard for Windows Mobile 5 and later applications is to employ a two item menu at the bottom of the display as opposed to using a similar style menu as is found on desktop PCs running MS Windows This is to allow users with softkeys i e smartphones with two buttons left and right below their display to navigate more quickly and easily Of course as with all user interfaces there s always someone who doesn t like it FreeOTFE4PDA does give you the option to change back the older style though simply tap Menu View Opti
201. r blocksize when implementing some modes of operation e g CBC Important Don t read write to the input plaintext cyphertext buffer Only the output ones 13 11 Filename Extensions Volume files keyfiles and all other files created and used by FreeOTFE can have any file extension you wish to give them if any By default FreeOTFE uses the following Extension Description vol Volume file cdb Keyfile aka Critical Data Block cdbBackup Critical Data Block Backup 159 14 Known Bugs LUKS volumes which use the Tiger hash cannot be mounted correctly Certain combined mobile phone PDA devices have issues mounting volumes See FAQ for details of the specific models affected Both of the above issues are currently under investigation and should be fixed in a later version If you believe that you have found a bug in FreeOTFE it would be very much appreciated if you could get in touch and report it please see the section on Fault Bug Reporting 160 15 Fault Bug Reporting Although FreeOTFE should be pretty stable and have no faults it s always possible that you may find something not quite right In these cases it would be very much appreciated if you could email a fault report the address shown in the contact details If you have recently upgraded to a newer version of FreeOTFE please could you ensure that you have followed the upgrade procedure exactly before reporting a fault See Install
202. r particular security requirements FreeOTFE defaults to using the AES 256 cypher in XTS mode together with SHA 512 for hashing This should prove more than enough for the overwhelming majority of users Q How safe is FreeOTFE A FreeOTFE is about as pretty much just as safe as writing directly data to your hard drive without FreeOTFE encrypting it see also the FAQ What happens if my volume file is corrupted or damaged in some way Will I lose all my data If you forget your password however then by definition you will not be able to recover your data see also the FAQ Help I forgot my password I know it was something like Q What happens if my volume file is corrupted or damaged in some way Will I lose all my data A As with pretty much all OTFE systems if you were to corrupt a FreeOTFE volume is some way the damage your data would receive would be about the same as if you had stored it directly on your hard drive without FreeOTFE encrypting it For example If you mount a FreeOTFE volume file and then write a byte of data at random to somewhere on that mounted drive the effect would be exactly the same as if you had randomly written the same byte to a real hard drive On the other hand if you were to write a byte to data to a random location within an umounted FreeOTFE volume then the amount of damage caused would dependant on where that byte was written 1 If the volume file was created with a critical data
203. r settings by first checking for it in the same directory the executable FreeOTFE exe was located in If a settings file cannot be found in this location it will try and look for the same file in your user s profile If a settings file still cannot be found FreeOTFE will fallback to using configured default values for all settings Q After associating FreeOTFE with vol files from the options dialog I doubleclicked my vol volume file and nothing happened A The FreeOTFE drivers must be running in order for you to mount a volume by doubleclicking on it Please either install the FreeOTFE drivers see the installation section or start FreeOTFE s portable mode see portable mode section Q Why do volumes created with the FreeOTFE v2 00 and later have the extension vol A This is purely to maintain consistency with the PDA version see other FAQ for an explanation as to why the PDA version uses filename extensions FreeOTFE gives you complete freedom over what you name your volume files Q What is the difference between the Overwrite free space and Overwrite entire drive options under the Tools menu A These options are largely self explanatory The Overwrite free space option will simply overwrite all unused storage on the selected volume The Overwrite entire drive option is more destructive it will overwrite all storage on the selected volume including overwriting destroying any da
204. re susceptible to this attack since they have to store encryption keys in memory in order to use them 2 Regardless of whether you use any form of disk encryption or not it is not recommended that you do power off reset your computer without first shutting down cleanly via the Start gt Turn off computer To prevent this attack in the situation described above ensure that the computer remains powered off for several minutes after it is turned off in order for the contents of RAM to effectively bleed away Summary In summary to completely remove the threat of this attack against your encryption keys 1 Dismount volumes after you have used them 2 If you must power off your computer while one or more volumes are mounted prevent anyone from powering it back on and dumping it s memory out for at least the first few minutes after it was powered off or the first 15 20 minutes if they open up the case and spray coolant on the memory chips 96 In short just use common sense Notes It should be noted that this attack is not limited in any way to disk encryption systems The focus on these systems by the authors of the above paper is a red herring Essentially the attack consists of attempting to take a snapshot of the PC s memory at the time it was reset which can then be picked over at leisure Any encryption system can be attacked in this way Furthermore because this attack may allow whatever was in the computer s memory at
205. required to decrypt your encrypted volume it may still be wise to overwrite data before its deletion This way should an attacker be able to decrypt your volume s they will not be able to use data recovery tools to retrieve sensitive data Q What is the difference between the main FreeOTFE FreeOTFE Explorer release and the PortableA pps com version 99 A The PortableApps com version is identical to the main FreeOTFE FreeOTFE Explorer release but includes an additional Launcher executable which simply starts FreeOTFE exe FreeOTFEExplorer exe Directory structure required to integrate it into the PortableApps com menu software Configuration files required to integrate it into the PortableApps com menu software Further the installer has been created using the PortableApps com installer creator software instead of the standard FreeOTFE NSIS installer and the translation source files po files which aren t needed to use the software have been removed Q What is the difference between the main FreeOTFE FreeOTFE Explorer release and the U3 version A The U3 version is identical to the main FreeOTFE FreeOTFE Explorer release with the exception that a slightly different directory structure is used to support the U3 platform and the translation source files po files which aren t needed to use the software have been removed The u3p file is simply a ZIP archive which has been renamed it may be renamed to ha
206. rypted data means WARNING Do not let MS Windows format this partition Although formatting the virtual drive FreeOTFE creates after mounting your encrypted partition is certainly a requirement before it can be used formatting the partition it resides on could destroy your encrypted data The safest course of action is to prevent MS Windows from allocating a drive letter to the encrypted partition By doing so MS Windows will not prompt you every time this drive is accessed since you will not be able to accidentally access it You ll be less likely to hit OK and format the partition overwriting your encrypted data To do this see the FAQ How do I hide an encrypted partition such that MS Windows doesn t allocate it a drive letter Q How do I hide an encrypted partition such that MS Windows doesn t allocate it a drive letter A Carry out the following steps 1 Go to Start gt Settings gt Control Panel gt Administrative tools gt Computer Management 2 Select Disk Management 3 Rightclick on the partition you have setup an encrypted and select Change Drive Letter and Paths 4 Remove any drive letters associated with the partition Windows should then remove any drive letters associated with the encrypted partition Q Why does the partition disk selection display sometimes display less information A Depending on the user s access rights FreeOTFE may only be able to obtain limited inf
207. ryption key used for the encrypted partition image the method used for generating sector IDs and a check hash See below for further breakdown Encrypted partition image User defined max 2464 bytes circa 16777216 TB This is a literal partition image which represents the volume This image is encrypted with 1 The master key 2 The user s chosen cypher 3 The user s chosen method for generating different sector IVs Total size 4096 Encrypted partition image size 13 2 1 3 Breakdown Critical data block layout Password Encrypted Random padding salt block 1 Item name Size in bits Description Password salt sl User specified to a max 512 This data is appended onto the user s password before it s hashed The resulting hash may then be used to encrypt decrypt the Encrypted block Encrypted block If bs gt 0 then 4096 salt length div bs bs If bs lt 0 then 4096 salt length This block contains the actual key which is used to encrypt decrypt the encrypted partition image See below for further breakdown Random padding 1 4096 sl bs Random padding data Required to pad out any remaining unused bits in the critical data block Total size 4096 125 13 2 1 4 Breakdown Encrypted block layout Check hash Volume details block As described above this entire block is encrypted using the user
208. s FreeOTFE will be automatically installed on your PC If you are using the 64 bit version of Windows Vista Vista x64 you will have to reboot your PC after the automatic installation is complete 3 1 2 Manual installation 1 Uncompress the release ZIP to where you would the software installed 2 Login to your computer as administrator if appropriate installation of the device drivers requires administrator privileges to create the registry entries etc 3 Create shortcuts to FreeOTFE exe if required 4 Launch FreeOTFE exe You will be prompted that the system could not connect to the main FreeOTFE driver ignore this error for now as you have not yet installed the main FreeOTFE driver 5 Select File Drivers If you are running under Windows Vista you will see the standard UAC consent credential dialog at this point because you are about to install a device driver which requires Administrator privileges Authorise FreeOTFE to continue by clicking Allow or entering your Administrator s password to continue 6 Install each of the sys files included with the release in turn as follows 1 Click the Install button 2 Select the sys file to be installed from the release and click OK This should copy the driver file into your lt windows gt system32 drivers dir and setup a few registry entries 3 Select the driver s name which should now appear in the list of installed drivers and click Start
209. s is fairly limited Alternativly FEEDBACK If you have any comments or suggestions for how FreeOTFE can be improved get in touch Q Which of the hash cypher algorithms should I use A This decision is left up to the user Most users can simply accept the default algorithms offered which provides a fairly high degree of security Q Which of the random number generators RNGs should I use A This decision is left up to the user Using more than one RNG increases the security offered by FreeOTFE as the combined random data generated will be at least as random as the most random RNG selected Should one of the RNGs subsequently be found to be weak i e producing data that is not as random as it should be the random data used will still be as strong as the strongest RNG used See the Technical Details Random Number Generators RNGs section for further information Q Is FreeOTFE based on CrossCrypt A The answer to that is an emphatic NO FreeOTFE and CrossCrypt are two completely separate projects written by completely different people It s easy to see why users may get the idea that FreeOTFE is based on CrossCrypt CrossCrypt was released first and the CrossCrypt s GUI CrossCryptGUD looks practically identical to FreeOTFE s interface The reality is that CrossCrypt itself is a command line based OTFE system it has no GUI CrossCryptGUI was a project I created to provide a GUI to CrossCrypt to improve its ea
210. s password salt and chosen hash and cypher algorithms As this block is encrypted its length in bits must be a multiple of the cypher s blocksize Item name Size in bits Description This is the hash of the plaintext version of the Volume details block Check hash If hk is zero then this hash will be either truncated to 512 bits or right padded with 0 bits up to a maximum of 512 bits Volume Total size hk This stores the details of how to encrypt decrypt the encrypted details partition If bs gt 8 then 4096 sl bs bs Total size Note represents integer division If bs lt 8 then 4096 sl 13 2 1 5 Breakdown Volume details block layout Encrypted partition image length Critical data Volume Master key Master Requested Random version length key drive letter padding 2 Finally we reach the details that the critical data block was designed to protect 126 Item name Size in bits Description Critical data version This is a version ID which identifies the layout of the remainder of the volume details block When this layout format is used this will always be set to 1 Volume flags Bitmap flagging various items Currently this only identifies which method is used in generating sector IVs used in encrypting decrypting the encrypted partition image Bit Description 0 Use different IVs for each sector 0 Use NULLIV 1 Use
211. s present then it will be XORd with the IV generated using this method before it is used for encryption decryption In all cases the sector IV generated will be right padded truncated to the cypher s blocksize If the cypher s blocksize is lt 0 then this must be set to 0 Sector IV generation 0 No sector IVs Null sector IV method 1 Sector IV is the 32 bit sector ID LSB first 2 Sector IV is the 64 bit sector ID LSB first 3 Hash of the 32 bit sector ID sector ID is LSB first 4 Hash of the 64 bit sector ID sector ID is LSB first 5 ESSIV The Volume flags item is used to determine the location of sector zero start of encrypted data or start of host file partition Random padding data Required to pad out the encrypted block to a multiple of bs and to increase the size of this block to the maximum length that can fit within the critical data block Random padding 2 Total size 13 2 3 5 Miscellaneous Comments Regarding the CDB Layout The design of the critical data layout eliminates the need for the cypher hash used to be stored anywhere denying an attacker this information and increasing the amount of work required to attack a volume file The password salt appears before the encrypted block and no indication of the length of salt used is stored anywhere in order to prevent an attacker from even knowing where the encrypted block starts within the CDB The Check MAC is
212. s though then you could certainly write an application which would carry out a brute force attack on your volume assuming those known characters How long this would take to run would depend on the cypher used the strength of your password and how much you remember of it Note This is not a security risk that last comment equally applies to pretty much any OTFE system which has been implemented correctly Q Can I store an encrypted volume on a compressed NTFS drive A Yes though there is nothing to be gained from compressing encrypted data as it is unlikely to compress by any significant amount if at all Q What hash algorithms does FreeOTFE use A A full list of the hash algorithms used by FreeOTFE can be found on the introduction page Q What encryption algorithms does FreeOTFE use A A full list of the cyphers and cypher modes used by FreeOTFE can be found on the introduction page Q Which cypher modes does FreeOTFE support A With the exception of the NULL and XOR cyphers FreeOTFE offers CBC LRW and XTS modes and has the flexibility for other modes to be easily added by simply changing drivers A full list of the cyphers and cypher modes used by FreeOTFE can be found on the introduction page 92 Q Which is the best encryption algorithm to use A That is a difficult question to answer The best advice that can be given here is to research the cyphers available and make your own decision based on you
213. same host volume by using different offsets If you create a hidden volume within an existing volume be warned subsequently mounting and adding data to the host volume can potentially result in parts of the hidden volume being overwritten and its data destroyed This is by design and increases the security of the hidden volume Please see the Plausible Deniability section for further information on the practical uses and considerations of hidden volumes 24 5 4 Volume Creation Advanced Options At the end of the volume creation process FreeOTFE will display a summary of the volume it is about to create At this stage more advanced options be configured for the new volume by selecting the Advanced button PC version or by selecting Menu Next and Menu Back PDA version Advanced Options Key Iterations Salt Drive Letter CDB Location FreeOTFE4PDA 11 09 ok Please enter the number of PBKDF2 key iterations to be carried out on your password to generate an encryption key ps6 a The higher the number the greater the security offered but the slower Length of salt F bits mounting will be especially if mounting the volume on a PDA Please enter the amount of salt to be combined with your password to generate an encryption key Note IF this value is changed From its default you will be required to enter it value every time you mount your volume For this reason it is recommended that
214. save settings when mounting Linux volumes Volumes can now be mounted as removable drives no recycle bin files deleted directly User s password is now processed with PKCS 5 PBKDF2 HMAC instead of being salted and hashed Improved handling if more than one hash cypher can be used for encryption decryption Added the following cyphers DES 3DES Blowfish RC6 CASTS libtomcrypt version of Twofish Added the following hash algorithms Tiger Whirlpool Added per volume IVs Rewrote most of the driver control dialog Critical data block checksum now uses the HMAC of the volume details block instead of its hash Fixed bug that could cause new volumes to be created with an extra newline tacked onto the end of the user s password If you have problems mounting volumes created like this you should still be able to mount them by entering an extra newline just press lt ENTER gt at the end of your password Fixed bug that caused VolumeFlags to be read back from the volume incorrectly In order to continue support for older CDB format 1 volumes these volumes will still be read incorrectly but newer CDB format 2 volumes are processed correctly To update older volumes to use the later CDB format simply change your password via the Tools Change volume keyfile password details menuitem It is highly recommended that you do this anyway in order to better ensure future compatibility v0 00 02 BETA 1 11th October 2004 O
215. se of use 86 In actual fact far from FreeOTFE looking a lot like CrossCryptGUI it s actually the other way around CrossCryptGUI looks a lot like FreeOTFE The Delphi GUI to FreeOTFE was already developed before CrossCrypt was released For the sake of expediency I dropped the CrossCrypt Delphi component I wrote into FreeOTFE s GUI hijacking it to produce CrossCryptGUI a cannibalized version of the FreeOTFE interface The cyphers supplied with the first public release of FreeOTFE v00 00 01 were the same as those used by CrossCrypt Originally I had planned to release the first beta of FreeOTFE for compatibility testing with only the NULL XOR DES and AES cyphers these apparently being the most common cyphers used with Linux volumes After CrossCrypt was released which uses AES and Twofish DES was the only cypher in the above list I had not implemented I decided to switch from DES to Twofish in order that people without Linux could easily use CrossCrypt to verify that FreeOTFE was operating correctly with AES and Twofish volumes and vice versa benefiting both systems Since its initial release FreeOTFE has seen significant developments including support for many more hashes cyphers and other options Q Is FreeOTFE based on Linux s losetup A No FreeOTFE is a completely separate project in its own right It was only after I realised how simple Linux encrypted losetup volumes are they are nothing more than an encry
216. secret key to be used to encrypt your volume CDB keyfile Click Secure 10 In the dialog shown specify the volume keyfile to be encrypted If you are trying to secure a hidden volume enter the host volume s filename partition 11 Leave the offset field set to zero unless you are trying to secure a hidden volume in which case this should be set to the offset where the hidden volume may be found 12 Click OK oOo won Note More than one secret key can be stored on a single token however they must all have different names The same secret key can be used to encrypt more than one volume CDBfkeyfile To use a volume keyfile which has been double encrypted by a token 1 Follow the normal procedure for mounting your FreeOTFE volume 2 When shown the password prompt click the Advanced gt gt button to display the Advanced security details options 3 Enter your token s PIN and click OK 4 Select the secret key used to secure your volume keyfile and proceed as normal by entering your volume keyfile s password etc and clicking OK to mount 7 4 PIN Entry FreeOTFE will only prompt you to enter your token s PIN as and when it s needed FreeOTFE does not cache your PIN in any way Security Token Smartcard PIN Please select appropriate security token smartcard and enter its PIN a C Use secure authentication path PKCS 11 PIN entry The PIN entry prompt will display a list of a
217. ss an encrypted volume on a PC which doesn t have FreeOTFE installed and on which you don t have Administrator privileges please use FreeOTFE Explorer Q Why do I need Administrator rights to start portable mode A Administrator rights are required to start portable mode starting portable mode implicitly registers the FreeOTFE drivers on the computer it s running on When portable mode is stopped they are unregistered 103 Administrator rights are required for this operation for the same reasons as given for the answer to Why do I need Administrator rights to install FreeOTFE To access an encrypted volume on a PC which doesn t have FreeOTFE installed and on which you don t have Administrator privileges please use FreeOTFE Explorer Q Can FreeOTFE run under MS Windows 95 98 Me A No and there are currently no plans to port FreeOTFE to Windows 9x based systems due to the different driver model used Q Can FreeOTFE run under Linux A No although FreeOTFE can read write and create volumes which can be used under Linux FreeOTFE Explorer however can be used under Linux when run under Wine Q How can I get FreeOTFE to mount my volumes at startup when I login A By creating a shortcut with suitable command line parameters in your Startup directory click the MS Windows Start button then go to Programs Startup FreeOTFE can mount volume files after your system starts up you login S
218. ss of either creating a process of aiher ers ven anew Dette new FreeOTFE volume file or a hidden volume within an existing file volume file or a hidden volume within an If you are unsure as to how to answer any of the questions this wizard existing file asks simply accepting the default values should generate a volume A If you are unsure as to how to answer an that is secure enough for most purposes H Y of the questions this wizard asks simply accepting the default values should Please click Next gt to continue generate a volume that is secure enough for most purposes Please click Next gt to continue Stage 1 of 8 CO PC version PDA version New volume wizard When prompted to select between creating a file or partition based volume new users should select File This is the safer of the two options partition based volumes are intended for more advanced users Some users who are unfamiliar with disk encryption systems may not understand all of the options they are presented with If you feel that you are in this position you should probably simply accept the default values you are presented with which will give you a volume that will be secure enough for your needs FreeOTFE is a highly flexible system that caters for both novice and advanced users alike many of the options that the volume creation wizard provides you with are intended for more advanced users who understand the implications of the opt
219. sted A Please see FreeOTFE s for up to date information on language translations Q How do I translate FreeOTFE into a different language A Please see FreeOTFE s for up to date information on language translations Q Can I defragment encrypted volumes A Yes There are two things that you may wish to defragment 1 File based volumes only The drive on which the volume file is stored i e defragmenting a volume file Once dismounted a volume file can be treated just like any other file Volume files can be defragmented by then running any defragmentation tool on the drive it s stored on 2 The filesystem stored within the encrypted volume i e defragmenting the encrypted files stored within the volume By mounting a volume you can defragment the encrypted data stored within it Again you can use any tool for this with the exception of Raxco s PerfectDisk 2008 Diskeeper Corporation s Diskeeper The defragmentation tool which comes bundled with Windows which is a simply a stripped down version of Diskeeper The above systems have limitations which prevent them from seeing mounted volumes all other tools will work as normal Examples of defragmentation tools which work with FreeOTFE volumes include e 0 amp 0 Defrag e Defragater e Auslogics Disk Defrag o Obit Smart Defrag e J e kDefrag Ultra Defragmenter and the vast majority of other defragmentation tools E 106
220. t lt CTRL gt when selecting driver files in the Open dialog shown when Install is clicked 5 6 2 Modify Existing Drivers The lower half of the Driver Control dialog lists all drivers currently installed together with their status indicated with the icons listed below 30 Column Description Driver must be started manually Start up Driver will be started automatically when the computer starts up Driver is installed normally no icon Installation mode Driver is installed in portable mode world icon Driver started Driver stopped After selecting an installed driver from the list the operations listed below may be carried out on it 5 6 2 1 Driver startup Changes whether the selected driver is automatically started when the PC boots up After changing this setting click Update for the change to take effect 5 6 2 2 Change driver status The start stop buttons start and stop the selected driver 5 6 2 3 Uninstall Uninstalls the selected driver and removes it from the drivers list 5 7 Enabling Disabling Hash Cypher Algorithms al This section applies to the PDA version of FreeOTFE only FreeOTFE4PDA comes with a wide range of hash cypher drivers From v3 75 onwards however only the SHA hashes i e SHA 1 SHA 224 SHA 256 SHA 284 and SHA 512 and AES cyphers are enabled by default This change was introduced to improve performance for the majority of users se
221. t Selected disk partition properties can now be accessed via context menu item When mounting a file based volume which is readonly the readonly checkbox will automatically be selected Change made such that if FreeOTFE s MRU list is disabled this is the default then volumes keyfiles etc will not appear on the MS Windows system MRU list either Added Greek language translation Added Croatian language translation Cosmetic display tweaks to better handle translations v5 10 13th October 2009 O o00o0o 0 O O O O O Added volume padding option when creating new volumes Added Czech translation Added Japanese translation Updated German and Spanish translations Added option to automatically start FreeOTFE on system startup Added option to let user define action carried out on clicking doubleclicking system tray icon Added options to allow prevent newlines and tabs in passwords Added minimize command line switch and modified to honor run minimized option when launched via a shortcut Fixed bug causing hotkeys to be registered even if run with commandline arguments Fixed bug causing emergency dismount hotkey to be treated as normal dismount hotkey Various cosmetic improvements v5 00 22nd July 2009 O Ooo0o O oo0o0o Significant performance improvements made to driver code Added XTS mode to Gladman cyphers AES MARS RC 6 Serpent and Twofish Added RIPEMD 256 and RIPEMD 320 hash algorithms Added
222. t Options Library tab 2 Add the path to the modified Delphi files included in SDeanComponents to fix various bugs relating to Delphi 2006 s Windows Vista support to the top of Delphi s standard library paths This step probably won t be needed with later versions of Delphi and shouldn t be carried out with older versions of Delphi which will have different source 3 Open the FreeOTFE Explorer project FreeOTFEExplorer dpr 4 If you have the dxgettext software installed see above ensure that the compiler directive _DXGETTEXT is set Otherwise make sure that this compiler directive is not set 5 Build the application 6 You should now find a file called FreeOTFEExplorer exe in the directory above the src directory You have now successfully built the GUI frontend 13 9 3 2 Building the DLL drivers To build the DLLs used by FreeOTFE Explorer 1 Open FreeOTFE4PDA sIn using Visual C 2 Set the build configuration within Visual C to Release Win32 3 Rightclick on each project in turn and select Rebuild Note Don t bother building the GUI project at present this can only be built for the Windows Mobile platform A copy of the binary which is built will be copied into the directory above your src directory 13 9 4 Building the Command Line Decryption Utilities Note The development of the command line decryption utilities has ceased This functionality has been superceded with the deve
223. t eliminates the need for the cypher hash used to be stored anywhere denying an attacker this information and increasing the amount of work required to attack a volume file The critical data block is encrypted The password salt appears before the encrypted block and no indication of the length of salt used is stored anywhere in order to prevent an attacker from even knowing where the encrypted block starts within the critical data block The Check hash appears before the volume details block This may seem a little strange since the size of Check hash is variable its actual length is dependant on the hash algorithm chosen but appears first in order to reduce the amount of known or predictable data early on in the volume Theoretically this is desirable as for example cyphers operating in CBC or similar modes which whiten data will do so with data that is less predictable than would occur if the hash appeared towards the end of the block it appears in The Check hash is limited to 512 bits This is limited as in practical terms some kind of limit is required if the critical data block is to be of a predetermined size See section on mounting volume files for how multiple matching check hashes is handled The Password salt is fairly arbitrarily limited to 512 bits Again this is primarily done for practical reasons Although at time of writing 2004 this limit to the length of salt used should be sufficient
224. t of command line decryption utilities Can t anyone can just decrypt my data When I mount a volume and then view its properties under FreeOTFE it states that the hash algorithm used is n a but I used a hash algorithm FreeOTFE is currently available for free are you intending to sell out later and start charging for it once enough users have been hooked on it FreeOTFE may always be free but will an enhanced version which is charged for with extra features be released perhaps under a different name What about klonsoft s LockDisk and WinCrypto LLC s CryptoDisk Aren t they paid for packages which are based on FreeOTFE How can I be sure that there are no backdoors in FreeOTFE Do FreeOTFE volumes have any kind of identifying signature By examining a FreeOTFE encrypted Linux volume file can anyone tell what it is What is plausible deniability What do the numbers and letters after a hash name mean What do the numbers and letters after a cypher name mean When creating a new volume file why do I get a message asking me to ensure I have XX XX GB free on the relevant drive I tried to create a large volume gt 4GB and FreeOTFE stopped halfway through with an error why What is the largest volume that I can create Can I store an encrypted volume on a compressed NTFS drive What hash algorithms does FreeOTFE use What encryption algorithms does FreeOTFE use 82 Which cypher modes does Free
225. t the SHA 512 512 1024 hash Make sure that the Hash with A s if hash output is too short is not checked Leave iteration count at 0 4 Encryption tab Select the AES CBC 256 128 cypher Select the 32 bits sector IV IV generation method e Set Sector zero location to Start of host file 5 File options tab Leave offset at 0 Leave sizelimit at 0 6 Mount options tab Select any unused drive letter 57 Leave readonly unchecked 7 Click the OK button 9 8 7 Example 5 Volume Encrypted Using 256 bit AES and rmd160 Hash This example demonstrates use of a Linux AES256 volume using the rmd160 hash to process the user s password instead of the default SHA hash WARNING Note that this example uses the rmd160 and not ripemd160 hash Creating the volume file under Linux dd if dev zero of vol_aes256_rmd160 bs 1k count 1024 losetup e AES256 H rmd160 dev loop0 vol_aes256_rmd160 Enter password password1234567890ABC mkdosfs dev loop0 mkdir test_mountpoint mount dev loop0 test_mountpoint echo This is a text test file gt test_mountpoint SHORT_TEXT txt cp TEST_FILE_1 dat test_mountpoint cp TEST_FILE_2 dat test_mountpoint cp TEST_FILE_3 dat test_mountpoint umount dev loop0 losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume file 3 K
226. ta that may have been present on it Because the latter option is more destructive it may only be used when a single mounted volume has been selected within the FreeOTFE user interface Q Does FreeOTFE support encrypting data with multiple cyphers aka cascaded cyphers or superencryption A Yes FreeOTFE allows volumes to be nested one inside another with complete flexibility as to which encryption options are used with each volume This means that you can for example have AnAES XTS with SHA 512 encrypted volume stored within A Blowfish LRW using Tiger encrypted volume stored within A Serpent CBC ESSIV using RIPEMD 320 encrypted volume In this example any data stored within the innermost AES encrypted volume will be actually be triple encrypted with AES Blowfish and Serpent before written to disk 105 Obviously there is a performance impact in encrypting data more than once as there would be in any system which encrypts data multiple times It s debatable how much this will increases security by though in principle the innermost volume in which sensitve files are stored will be secured at least as strongly as the strongest cypher used Should any of the cyphers be found to be weak at a later date this will still hold true Note Volumes nested in this manner must be dismounted in the reverse order to which they were mounted Q FreeOTFE supports different languages but why isn t mine li
227. te 2GB encrypted disk image plus a separate 512 byte keyfile which may be stored in a separate location to the volume Note that if you store the volume s CDB in a keyfile you will always need to supply a keyfile when mounting the volume and ensure that the Data from offset includes CDB advanced option shown on the FreeOTFE password entry dialog shown when mounting must be unchecked after the keyfile is specified By default FreeOTFE includes the CDB will be included as part of the volume 5 4 5 Padding Padding is additional random data added to the end of a volume file Any padding added will not be available for use as part of the mounted volume and serves to increase the size of the volume Encrypted volumes typically have a file size that is a multiple of 512 bytes or a signature size beyond the last IMB boundry To prevent this you may wish to append random padding data to the new volume 26 Padding also reduces the amount of information available to an attacker with respect to the maximum amount of the encrypted that may actually be held within the volume 5 5 Password Entry Advanced Options Note This section only covers the password entry dialog shown when mounting FreeOTFE volumes For mounting Linux volumes please see the section on Linux volumes FreeOTFE Key Entry Security details Password J FreeOTFE4PDA 10 52 ok Keyfile Eile a Offset bytes PKCS 11 e
228. te of the FreeOTFE project Functionally this software has one task to decrypt the encrypted partition area of FreeOTFE volume files and to write out the plaintext version for examination This software is considerably easier to understand than the kernel mode drivers and does not require the Microsoft SDK DDK to be present As a result any competent software engineer should be able to modify the software as appropriate and confirm that data is being encrypted correctly by the FreeOTFE system This software is not intended for general public use but by those who understand and can write C In order to use it modifications to the source code will most probably be required to change the decryption keys used if nothing else For this purpose the command line decryption utilities are not released in binary form only as source code which must be compiled by the user 22 2 Operation Each of the command line decryption utilities is designed to operate in the following manner 1 Open the input encrypted volume file The filename used is hard coded to inFile dat obviously this may be changed as required 2 Open Create the output plaintext volume file The filename used is hard coded to outFile dat obviously this may be changed as required 3 Generate an IV if required The method of generating the IV may vary dependant on how the volume was encrypted 4 Read in a sector s worth of data from the input encrypted f
229. test_mountpoint cp test_files BINARY_ABC_RPTD dat test_mountpoint cp test_files BINARY_OO_FF_RPTD dat test_mountpoint umount test_mountpoint losetup d dev loop1l cryptsetup luks luksClose myMapper losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the losetup volume file 3 In the dialog shown enter password1234567890ABC as the key and set any of the options wanted 4 Click the OK button 9 10 7 Example 5 Volume Encrypted Using 256 bit Serpent XTS This example demonstrates use of a LUKS Serpent 256 volume in XTS mode Creating the volume file under Linux dd if dev zero of volumes vol_serpent_xts losetup dev loop0O volumes vol_serpent_xts echo password1234567890ABC cryptsetup luks cryptsetup luks luksDump dev loop0 echo password1234567890ABC cryptsetup luks dmsetup 1s dmsetup table dmsetup status cryptsetup luks status myMapper losetup dev loop1l dev mapper myMapper cat test_files 2MB_Z dat gt dev loopl cat test_files 2MB_0x00 dat gt dev loopl mkdosfs dev loop mkdir test_mountpoint mount dev loopl test_mountpoint vol bs 5M count 1 vol c serpent xts plain s 512 luksFormat dev loop0 luksOpen dev loop0 myMapper cp test_files SHORT_TEXT txt test_mountpoint cp test_files BINARY_ZEROS dat test_mountpoint cp test_files BINARY_ABC_RPTD dat test_mountpoint cp test_fi
230. the drive At that point the drive disappears and the encryption decryption key is overwritten in memory making your data totally inaccessable until the password and other parameters if needed are supplied and the volume is mounted again The following sections give more detailed instructions on how do carry out each of these steps 4 3 Creating a new volume In order to use FreeOTFE you must first create a disk image called a volume to represent your virtual drive This is a fairly straightforward process and consists of using FreeOTFE to create a large file or setup a partition on your computer s hard drive This volume will hold an encrypted disk image Technical of your virtual drive and is where FreeOTFE will store all data written to your virtual drive This file or partition can subsequently be mounted at which point a virtual drive will appear on your computer anything stored on one of these virtual drives will be automatically encrypted before being written to volume file To create a new volume select File New menuitem to display the new volume wizard which will guide you through the process in a series of simple steps FreeOTFE Volume Creation Wizard FreeOTFE4PDA 4 10 52 ok Welcome to the FreeOTFE Yolume Creation Wizard Welcome to the FreeOTFE Volume Creation Wizard This wizard will guide you through the This wizard will guide you through the proce
231. the volume under FreeOTFE 1 2 3 Select Linux Mount Select the volume file Key tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the SHA 256 256 512 hash Make sure that the Hash with A s if hash output is too short is not checked 56 Leave iteration count at 0 4 Encryption tab Select the AES CBC 128 128 cypher Select the 32 bits sector IV IV generation method Set Sector zero location to Start of host file 5 File options tab Leave offset at 0 Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button 9 8 6 Example 4 Volume Encrypted Using 256 bit AES This example demonstrates use of a Linux AES256 volume Creating the volume file under Linux dd if dev zero of vol_aes256 bs 1k count 1024 losetup e AES256 dev loop0 vol_aes256 Enter password password1234567890ABC mkdosfs dev loop0 mkdir test_mountpoint mount dev loop0 test_mountpoint echo This is a text test file gt test_mountpoint SHORT_TEXT txt umount dev loop0 losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume file 3 Key tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Selec
232. then it can still be accessed by Windows Explorer on the host PC by simply typing the drive letter the encrypted volume is mounted as followed by a colon into Windows Explorer s Address bar and pressing lt ENTER gt In the same manner volumes mounted on the host PC will be accessible from within the MojoPac environment 108 Q Can FreeOTFE be used with RAID arrays A Yes FreeOTFE has been tested with and works with RAID arrays Q Does FreeOTFE try to connect to the internet A No not by default FreeOTFE and FreeOTFE Explorer will only ever try to connect to the internet if it has been configured to check for updates and even then they will only try to connect to the FreeOTFE WWW site to retrieve version information By default both FreeOTFE and FreeOTFE Explorer are configured such that thtey will not check for updates this functionality must be explicitly enabled by the user Q How do I check FreeOTFE s exit code when passing parameters via the command line A The easiest way is to check FreeOTFE s exit code is to run it via a batch file For example if you create a FreeOTFE_cmdline bat file containing the following FreeOTFE exe 1 2 3 4 5 6 7 8 9 echo Exit code SERRORLEVELS and use FreeOTFE_cmdline bat in places of FreeOTFE exe Q Why won t FreeOTFE accept my password when supplied via the command line parameter A If you re using the silent
233. tilities Can t anyone just decrypt my data A The decryption software included with FreeOTFE is completely useless without the password used to encrypt your data And anyone with that information can decrypt your data anyway The command line decryption utilities are not some form of password cracking tool far from it they actually act to increase your security by allowing you to verify that encryption is actually taking place Q When I mount a volume and then view its properties under FreeOTFE it states that the hash algorithm used is n a but I used a hash algorithm A The hash algorithm shown is the one used to generate sector IVs If the sector IV generation method used does not require the use of a hash algorithm see the Sector IVs item on this dialog n a will be displayed for the hash algorithm This is separate from any hash algorithm used to process your password which in the case of FreeOTFE volumes can be seen in the output file of a CDB dump select Tools Critical data block Dump to human readable file or in the case of Linux volumes is specified at time of mounting 88 Q FreeOTFE is currently available for free are you intending to sell out later and start charging for it once enough users have been hooked on it A NO ABSOLUTELY NOT FreeOTFE is free and will always be free As much as anything else it would look a little silly if people had to pay for FreeOTFE Seriously
234. ting them Added create noexit and silent command line options Add confirmation message when exiting Options dialog with Save settings option turned off Removed redundant message shown on dismounting volumes Corrected fault requiring hidden volumes to begin at an offset which is a multiple of 512 bytes v3 76 19th April 2009 O Corrected minor fault in locking protecting FreeOTFE4PDA s internal list of device handles v3 75 4th April 2009 O O O Added option to enable disable hash cypher drivers from the user interface By default the SHA and AES drivers are enabled but all others are disabled to improve performance The user can easily enable others if required Driver code refactored to allow common code to be shared between FreeOTFE and FreeOTFE Explorer no functional changes Drivers moved into DLL subdirectory 170 v3 05 27th October 2008 O O O Resolved issue that causing Mount failed the virtual storage device could not be activated at this time error on some PDAs when mounting Updated documentation Development environment changed to Microsoft Visual Studio 2008 although older versions can probably still be used v3 00 16th December 2007 O O O O O O FreeOTFE4PDA is now available as a single CAB file and ActiveSync installer as well as a standard ZIP file making installation to a PDA even simpler Added LRW and XTS cypher mode support Tested under
235. uccessful mount Added option to display large or small toolbar icons Note Large icons with captions now shown by default This may be changed back to show small icons via the Options dialog Added option to save FreeOTFE settings to the Windows registry instead of a configuration file Added MRU list to system tray icon s menu Note The MRU list is disabled by default enable via the Options dialog Added offset command line option for mounting hidden volumes from the command line Message catalog system to simplify translation and reduce risk of errors 164 O O O Change to prevent changing the CWD when browsing for files via the standard open save dialogs This should stop FreeOTFE preventing USB drive removal when keyfiles etc are stored on USB drives Changed the broadcast message system informing other windows of drives appearing disappearing on mount dismount Corrected fault causing drive overwrite to fail under some circumstances with volumes over 4GB Refactored some parts of the codebase to eliminate duplicated code Various cosmetic tweaks to improve display layout when translated into different languages v4 40 20th November 2008 O O oo0o0o0o0 O O German translation added Added Tools menu item to provide a straightforward user interface to allow the user to quickly and easily copy FreeOTFE to a USB drive and optionally configure it to run automatically when the drive is plugged in Changed def
236. ude additional partition information which will not be understood by your PC Make sure that before attempting to mount your volume using the PDA version you have enabled the relevant hash cypher drivers used in securing the volume By default FreeOTFE4PDA only has the SHA xxx and AES algorithms enabled See Advanced Topics Enabling Disabling Hash Cypher Algorithms section for how to enable disable other hash cypher algorithms Q When creating a new volume how do I enable the sector IV options A Sector IVs are only used with cyphers using CBC mode to enable the sector IV options select an encryption algorithm which operates in CBC mode If you select a cypher which uses either LRW or XTS the IV options are automatically disabled as these algorithms don t use them Q Is FreeOTFE vulnerable to watermarking attacks A FreeOTFE volumes are not vulnerable to watermarking attacks as long as they are created with a cypher using XTS mode LRW mode CBC mode with ESSIV see the Create new volume wizard encryption settings step By default FreeOTFE creates volumes using XTS mode Users would have to deliberatly create their volumes using CBC mode with predictable IVs in order to be vulnerable to this type of attack 95 Q Is FreeOTFE vulnerable to Cold Boot Attacks on Encryption Keys aka DRAM attacks A No it isn t assuming common sense is used Description A cold boot attack involves reboot
237. uksDump dev loop0 echo password1234567890ABC dmsetup ls dmsetup table dmsetup status cryptsetup luks status myMapper cryptsetup luks bs 1M count 1 luksFormat dev loop0 luksOpen dev loop0 myMapper losetup dev loopl dev mapper myMapper mkdosfs dev loop1l mkdir test_mountpoint mount dev loopl test_mountpoint cp test_files SHORT_TEXT txt cp test_files BINARY_ZEROS dat cp test_files BINARY_ABC_RPTD dat cp test_files BINARY_0OO_FF_RPTD dat umount test_mountpoint losetup d dev loopl cryptsetup luks luksClose myMapper losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume file test_mountpoint test_mountpoint test_mountpoint test_mountpoint 3 In the dialog shown enter password1234567890ABC as the key and set any of the options wanted 4 Click the OK button 9 10 4 Example 2 Volume Encrypted Using 256 bit AES This example demonstrates use of a LUKS AES256 volume Creating the volume file under Linux dd if dev zero of volumes vol_aes_256 vol volumes vol_aes_256 vol losetup dev loop0 bs 1M count 1 echo password1234567890ABC cryptsetup luks luksDump dev loop0 echo password1234567890ABC dmsetup ls dmsetup table dmsetup status cryptsetup luks status myMapper cryptsetup luks c aes cryptsetup luks s 256 luksFormat dev loop0 luksOpen dev loop0 myM
238. umes is encrypted and as such it is not possible to identify it for what it is Q What is plausible deniability A See the documentation section on Plausible Deniability for details Q What to the numbers and letters after a hash name mean A When required to choose which hash you wish to use FreeOTFE will present you with a list of all hashes that are provided by the FreeOTFE drivers installed These lists will display hash names in the format lt hash name gt lt hash length gt lt block size gt Note The hash length and block sizes shown are in bits not bytes For example SHA 512 512 1024 This indicates that the hash used is SHA 512 which generates 512 bit hash values and processes data in 1024 bit blocks If the hash length shown is zero then the hash generates no output If the hash length shown is 1 then the length of the hash values returned can vary If the block size is 1 then the hash processes data using a variable block size Typically when presented with a selection of different hashes to choose from you will see a or button next to the list clicking this button will display full details on the driver 90 Q What to the numbers and letters after a cypher name mean A When required to choose which cypher you wish to use FreeOTFE will present you with a list of all cyphers that are provided by the FreeOTFE drivers installed These lists will display cypher names in the
239. unt when mounting a FreeOTFE volume Multiple driver files can now be selected for installation when manually installing drivers File Mount now also auto detects LUKS volumes so they can be mounted via this menuitem as well as File Linux volume Mount file Similarly dragging and dropping files onto FreeOTFE will cause it to attempt to auto detect the type of volume used Manually installed drivers will now start up as soon as they ve been installed and set to startup automatically on boot Removed short password warning when mounting a LUKS volume with less than 20 characters in its password Command line option to mount volumes will now accept relative paths to volume files Added command line options to install and uninstall drivers Added command line option to return the number of mounted volumes Added dialog to report all currently available hash cyphers algorithms together with their details see under Help menu Improved support for multimonitor systems Corrected fault with mouse RNG that would cause insufficient random data errors Main development environment changed to CodeGear Delphi 2007 Microsoft Visual Studio 2005 Professional Edition although older versions can probably still be used Updated LibTomCrypt based cypher hash drivers to use LibTomCrypt v1 17 v2 00 00 18th March 2007 O O Implemented support for Windows Vista although previous versions would work under Vista they had a few minor cosmeti
240. ur MojoPac system will be secured Because of FreeOTFE s portable mode MojoPac can be used as a fully mobile secured system by placing a copy of FreeOTFE onto your USB drive along with the volume file Method two Running within the MojoPac environment FreeOTFE can also be launched and used from within the MojoPac environment to create and use encrypted volumes in much the same way as on a normal PC In order to use FreeOTFE in this way you must first either Start FreeOTFE s portable mode on the host PC or Install and start the FreeOTFE drivers on the host PC See the Portable mode and Installation sections for further information When running MojoPac your MojoPac device i e your USB drive iPod etc will appear as both the removable drive it is normally mounted as on the host PC e g D E and as your MojoPac s C drive To mount a FreeOTFE volume which is stored on your MojoPac device you should select the volume file on the removable drive e g D E and not the mirror copy which appears on you MojoPac s C drive Mounting volumes stored elsewhere should be unaffected Note that when a volume is mounted from within the MojoPac environment it may also be accessed by the host PC by using the drive letter it is mounted as under the MojoPac session Applications on the host PC will see the mounted volume as normal with the exception of Windows Explorer which will not show a new drive icon for it though even
241. ve a zip file extension and uncompressed to verify its contents Q When dismounting a file based volume what does FreeOTFE do with the file timestamps A By default when mounting file based volumes FreeOTFE stores the volume file s timestamps and resets them back again after dismounting This is carried out for security reasons see section on plausible deniability This functionality can be turned off if needed e g to assist backup processes see FAQ How do I backup an encrypted volume by turning off the Revert volume timestamps on dismount option on the Options dialog View Options Q What is volume padding and why would I want it A A number of tools are available to detect encrypted volumes These typically operate by detecting large files with a high amount of entropy and a file size that is a multiple of 512 bytes or which is a certain signature size greater than the last IMB boundary Padding is additional random data added to the end of the volume and is used to prevent detection of FreeOTFE volumes by automated volume finding tools which only carry out a cursory search for volumes and rely on the size of files found Furthermore padding also reduces the amount of information an attacker has about a volume by preventing reliable detection of the size of the mounted volume subject to the mounted volume being overwritten as described in the Plausible Deniability section Padding will
242. ving to prove that the data found is not an OTFE volume or any other form of encrypted data 76 10 3 Hidden Volumes More advanced OTFE systems go one step further support for hidden volumes as FreeOTFE does Here you have a normal OTFE volume filled with data that you have no objection to disclosing to an attacker Mounting the volume with a different password causes the OTFE system to read a different part of the host volume file giving access to a separate hidden volume Here the concept of plausible deniability is much stronger theoretically an attacker is not able to determine let alone prove whether or not such a hidden volume is present However the implementation of such hidden volumes is not as trivial as it may seem at first In order for this approach to be successful the host volume file must be initialized by writing random data to it This is required since the host volume file may well have been created by simply writing 0x00 s to your HDD in order to generate a large enough file Any hidden volume stored within such a host volume file may well cause an attacker suspicion as to whether a hidden volume exists The hidden volume will appear as a large amount of high entropy data stuck in the middle of the volume file interrupting the neat pattern of 0x00 s The random data used for this process cannot simply be pseudorandom data given the size of a typical volume file even ones as small as a MB
243. volume each using a password of their own choosing Note Keyfiles are specific to the volume they are created for Although a keyfile for one volume may be able to successfully mount another volume the virtual drive shown will appear to be unformatted the files within the volume will remain securely encrypted and unreadable 5 1 1 Creating a new keyfile To create a new volume select Tools Create keyfile to display the keyfile wizard which will guide you through the process in a series of simple steps 5 1 2 Mounting a volume using a keyfile The process of mounting a volume using a keyfile is identical to the normal mount procedure with the exceptions that 1 The password used should be the keyfile s password and not the volume s password 2 The full path and filename of the keyfile should be entered as the keyfile file 21 5 2 Partition Entire Disk Based Volumes A This section applies to the PC version of FreeOTFE only As well as being able to storing encrypted volumes in flat files FreeOTFE also provides the option of encrypting partitions and even entire physical disks by selecting Partition disk when prompted during the volume creation process It is not recommended that inexperienced users do this is the kind of operation that should only be carried out by those familiar with disk partitioning and fully understand what they re doing 5 2 1 Safety Precautions It is extremely important th
244. volumes create an encrypted volume using Linux then mount it using FreeOTFE The encrypted Linux volume will be fully readable and writable using FreeOTFE confirming that the same encryption is taking place under FreeOTFE as Linux For FreeOTFE volumes the critical data block can be dumped out see Tools Dump to human readable file menu and the master encryption key used to mount the same volume under Linux offsetting for the CDB again proving that encryption is taking place WARNING Contrary to popular belief a user interface which accepts and processes encryption test vectors does not prove anything It is a trivial task to take a secure cypher and use it to process test vectors provided by the user while actually using a very weak and insecure cypher to carry out encryption decryption on the data being stored Q When selecting a cypher to use why do the same cyphers appear multiple times A This is because you have more than one version of a particular cypher driver installed See also Why are there duplicated cypher drivers Q Why are there duplicated cypher drivers A The duplicated drivers implement the same algorithms but are built from different crypt libraries For example there are three Twofish drivers one based on the Hi fn and Counterpane Systems Twofish implementation another which uses the libtomcrypt implementation and a third which relies on the Gladman implementation They redundant
245. with CDRWs It is recommended that volumes which are to be written to CD are formatted using either the FAT or FAT32 filesystem NTFS volumes will work under Windows XP though AFAIR Windows 2000 is unable to mount NTFS volumes read only meaning the volume must be copied back to your HDD the file set to read write and then mounted Q Can I use FreeOTFE over a network A Yes By installing FreeOTFE on the computers you wish to access your data from you can mount a volume file located on a networked server When mounting over a network simply specify the UNC path e g servername sharename path volumefilename to the volume file begin mounted When a volume is mounted over a network in this way all data read written to that volume will be sent over the network in encrypted form If you wish to mount a networked volume file by more than one computer at the same time you may do so provided that they all mount the volume read only If any computer has a volume file mounted as read write you should dismount all other computers even if they were accessing the volume as read only and ensure no other computer mounts the volume until the computer mounted as read write has dismounted Q Why do I get Unable to connect to the FreeOTFE driver errors A This message indicates that you have either not installed the main FreeOTFE driver FreeOTFE sys or you have not started it yet It is normal to see this message in the follow
246. y recommended that you now initialize the volume by writing data to all its sectors before making any further use of it This process is recommended because if omitted it may be possible for an attacker to determine the amount of data you have stored on your volume file as stated above the actual process of creating the volume file consists of creating a suitably large file filled with zeros Note It is important that this step be carried out if you intend using the volume file just created as a host file for storing a second hidden encrypted volume 9 Switch back to FreeOTFE and select Tools Overwrite free space 10 Click Yes when prompted if you wish to proceed FreeOTFE will then write pseudorandom data to the drive which will then be encrypted before being written to the volume file 9 2 Hiding a Linux Volume Within Another Volume To create a Linux volume within another volume file 1 Create a FreeOTFE Linux volume as normal ensuring that you initialize the volume by mounting it formatting it and then overwriting all its free space 2 Unmount the host volume 3 Remount the host volume but specify a reasonable offset on the File options tab of the Linux mount dialog 9 3 Mounting Volumes Created under Linux Select File Linux volume Mount file Mount partition Enter the volume s password and set all appropriate options Click OK Note that if you do not 1 Set the same options as us
247. y FreeOTFE sha512 Supported by FreeOTFE ripemd160 Supported by FreeOTFE 9 7 Additional Notes on Linux Volumes Linux volumes should be formatted as FAT FAT32 NTFS in order for them to be recognised by MS Windows Although it should be possible for MS Windows can to understand other filesystems e g ext2 ext3 riserFS this does require 3rd party filesystem drivers to be installed If you do wish to read an ext2 ext3 formatted volume from MS Windows the filesystem drivers listed below are suggested There may well be others though at time of writing 23rd December 2005 these are the only ones that I have checked Package URL Description Ext2 Installable Supports both read and write File System For _ http www fs driver org operations with ext2 ext3 Windows Freeware but closed source Supports ext2 readonly Open source EXT2 IFS for Windows http uranus it swin edu au jn linux ext2ifs htm Further information on Linux volumes may be obtained from Cryptoloop Cryptoloop HOWTO loop AES loop AES README m crypt WWW site m crypt Wiki LUKS UKS Linux Unified Key Setup dm crypt Note that for many of the controls on FreeOTFE s Linux mount volume dialog the equivalent Cryptoloop losetup parameter for that control is displayed in brackets 9 8 Examples Cryptoloop This section gives a series of examples of how to create Linux Cryptoloop losetup volumes
248. y and reliability of Windows 1KB938979 An update is available that improves the performance and reliability of Windows 1KB941649 An update is available that improves the compatibilit iability and stability o 1KB943078 MS07 066 Vulnerability in the Windows kernel could allow elevation of KB943899 An update that improves the performance responsiveness and reliability o Windows Vista is available Uninstalling the above should allow this method to work again though is hardly ideal Note This list of hotfixes was compiled from information taken from the following WWW sites Unable to Disable Integrity Checks Cause Drivers Not Found in 64 bit Vista x64 3 1 3 4 Method 3 TESTSIGNING ON Instructions 1 Open an elevated command prompt by either Clicking the Start button on the Windows taskbar type CMD in the search box and then press lt CTRL SHIFT ENTER3 gt to run CMD with administrator privileges or e Locating cmd exe under C Windows System32 in Windows Explorer rightclicking on this executable and selecting Run as Administrator from the context menu 2 Click continue or enter the administrator s password as appropriate and click OK when asked for permission to continue 3 In the command prompt window which appears type bcededit exe set TESTSIGNING ON 4 Reboot the PC This method is probably the best solution and allows FreeOTFE to run correctly However it does have
249. ying files stored on a normal magnetic hard drives however many flash drives employ wear levelling to reduce wear and prolong their useful life This can cause overwrite data to be written to locations on the disk other than where the data to be overwritten is stored As a consequence most if not all file overwrite tools are not be able to overwrite files stored on such flash drives even though it may report that they have operated successfully To securely overwrite files on flash drives please delete them as normal and then overwrite all remaining free space available on the device This will prevent any form of wear levelling from redirecting overwrite data to other parts of the disk and guarantee a successful overwrite Q How do I get FreeOTFE Explorer to display filename extensions for all files A Like MS Windows Explorer FreeOTFE Explorer default to hiding filename extensions for known file types To configure FreeOTFE Explorer to display filename extensions for all files please set your options as follows Select the View Options menuitem Select the Advanced tab Unselect the Hide extensions of known file types option Q Can FreeOTFE Explorer run under Linux A Yes FreeOTFE Explorer can be used under Linux when run under Wine 122 13 Technical Details 13 1 FreeOTFE Volumes and Keyfiles A FreeOTFE volume regardless of whether its stored in a file or partition consists of two
250. ypher 4 The first 512 bytes of the decrypted Encrypted block are split off and retained as a plaintext check MAC and Random padding 3 5 The remainder of the decrypted Encrypted block is assumed to be a Volume details block The HMAC of this Volume details block is generated using the current hash algorithm and the critical data key just used for decryption 6 The generated MAC is truncated to its first 512 bytes if it s longer than this 7 The resulting n bit MAC is compared with the first n bits of the Check MAC Random padding 3 8 If the MAC is identical to the Check MAC it is assumed that a valid cypher hash combination has been found the Volume details block is parsed and stored together with the hash cypher combination 9 Regardless of whether the generated MAC is identical to the Check MAC all remaining hash cypher combinations will be processed in the same manner to check if there are any other matching hash cypher combinations After all possible hash cypher combinations have been exhausted Ifnocypher hash combination successfully decrypted the Volume details block the user will be informed that they have entered incorrect details If more than one cypher hash combination successfully decrypted the Volume details block the user should be prompted to choose which of the combinations they wish to use The system will proceed as if only the user selected combination had been successfu
251. ypher used Note Although LUKS can create volumes with ESSIV ESSIV is not part of the LUKS specification Corrected errors that were displayed when a non admin attempted to access the driver control dialog v1 00 00 20th November 2005 O O O Added dismount hotkeys Added optional system tray icon tasktray icon together with ability to minimize close FreeOTFE to the system tray Added optional toolbar and statusbar Added command line support 167 Improved support for MS Windows XP Themes O Switched from Delphi 5 to Delphi 7 v0 59 00 BETA 29th July 2005 Minor change to FreeOTFE sys device driver to fix error introduced by compiler Specifically debug builds work correctly but for release builds the compiler handles the modulus operator differently for 64 bit arithmetic calling a kernel function _alldvrm that doesn t exist in Windows 2000 causing the driver to fail to load v0 58 00 BETA 24th July 2005 O Added support for cryptlib c132 dll as an RNG if installed O Added support for Linux LUKS volumes O Removed redundant warnings when run by a user without Administrative privileges v0 57 9900 BETA 8th June 2005 restricted test release Added support for encrypted CDs DVDs Added support for encrypting disk devices as well as partitions i e You can now encrypt an entire disk not just partitions held on it v00 57 00 BETA 28th May 2005 Compatibility with Linux volumes improved
252. ytes onto the end of the Encrypted block and pad out the end with random data to form the complete CDB 9 Write the CDB to either The start of the user s volume Akeyfile The user specified offset within the host volume if creating a hidden volume which includes a CDB 143 13 4 Mounting FreeOTFE Volumes To mount a FreeOTFE volume the following information must be obtained from the user The volume to be mounted The user s password If the CDB to be used for mounting is stored in a keyfile the location of the keyfile The length of salt used in the CDB sl The number of key iterations When mounting a hidden volume the following information is also required The offset within the host file volume that the hidden volume resides at If the offset specified gives the location of a CDB or the Encrypted partition image OANNDMN PWN e Although this list may sound as though it places a significant burden on the user to remember a significant amount of information However for most users the only information required will be the volume the wish to mount and their password all of the other details may be defaulted to sensible values unless the user chooses to take advantage of the more advanced features of FreeOTFE From the information supplied by the user the following can be determined automatically 1 The cypher used 2 The hash algorithm used 3 All of the details stored within Volume deta
253. zero of volumes vol_twofish_o3 vol bs 1K count 100 losetup dev loop0 volumes vol_twofish_o3 vol echo password1234567890ABC cryptsetup c twofish o 3 create myMapper dev loop0d dmsetup 1s dmsetup table dmsetup status losetup dev loopl1 dev mapper myMapper mkdosfs dev loop1l mkdir test_mountpoint mount dev loopl test_mountpoint cp test_files SHORT_TEXT txt test_mountpoint cp test_files BINARY_ZEROS dat test_mountpoint cp test_files BINARY_ABC_RPTD dat test_mountpoint cp test_files BINARY_OO_FF_RPTD dat test_mountpoint 66 umount test_mountpoint losetup d dev loop1l cryptsetup remove myMapper losetup d dev loop0 rm rf test_mountpoint Mounting the volume under FreeOTFE 1 Select Linux Mount 2 Select the volume file 3 Key tab Enter password1234567890ABC as the key Leave GPG executable blank Leave GPG keyfile blank Leave seed blank Select the RIPEMD 160 160 512 hash Ensure Hash with A s if hash output is too short is checked Leave iteration count at 0 4 Encryption tab Select the Twofish CBC 256 128 cypher Select 32 bit sector ID as the IV generation method Set Sector zero location to Start of encrypted data 5 File options tab Set offset to 1536 bytes i e 3 sectors each of 512 bytes Leave sizelimit at 0 6 Mount options tab Select any unused drive letter Leave readonly unchecked 7 Click the OK button

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