[dm-crypt] [ANNOUNCE] cryptsetup 1.3.0-rc1 (test release candidate)

Milan Broz mbroz at redhat.com
Mon Mar 14 18:44:05 CET 2011

The first cryptsetup 1.3.0-rc1 release candidate is available at


Feedback and bug reports are welcomed.

p.s. Please let me know if you tested crypto backend support
or loop-AES compatibility mode (and report problems, if there is any:-)


Cryptsetup 1.3.0 (rc1) Release Notes

Changes since version 1.2.0

Important changes
 * Several userspace crypto backends support

   cryptsetup now supports generic crypto backend interface which allows
   compile package with various crypto libraries, these are already implemented:

   * gcrypt (default, used in previous versions)
   * OpenSSL
   * NSS (because of missing ripemd160 it cannot provide full backward compatibility)
   * kernel userspace API (provided by kernel 2.6.38 and above)
     (Note that kernel userspace backend is very slow for this type of operation.
      But it can be usefull for embedded systems, because you can avoid userspace
      crypto library completely.)

   Backend is selected during configure time, using --with-crypto_backend option.

   configure --with-crypto_backend=BACKEND (gcrypt/openssl/nss/kernel) [gcrypt]

   Note that performance checked (iterations) in LUKS header will cause that
   real iteration time will differ with different backends.
   (There are huge differences in speed between libraries.)

 * Cryptsetup now automatically allocates loopback device (/dev/loop) if device
   argument is file and not plain device.

   This require Linux kernel 2.6.25 and above (which implements loop autoclear flag).

   You can see backing file in cryptsetup status output if underlying device is loopback.

 * Adds luksChangeKey command

    cryptestup luksChangeKey --key-file <old keyfile> <new keyfile> [--key-slot X] 
    cryptestup luksChangeKey [--key-slot X]  (for passphrase change)

   This command allows passphrase/keyfile change in one step. If no key slot is
   specified (and there is still free key slot on device) new slot is allocated before
   the old is purged.

   If --key-slot option is specified (or there is no free slot) command will overwrite
   existing slot.
   WARNING: Be sure you have another slot active or header backup when using explicit
            key slot (so you can unlock the device even after possible media failure).

 * Adds compatible support for loop-AES encryption type in loopaesOpen command.

   Linux dm-crypt in 2.6.38 and above supports loop-AES compatible mapping
   (including multi-key and special CBC mode, all three modes are supported).

   If you have raw loop-AES keyfile (text file with uuencoded per-line keys), you can
   access loop-AES volume using
     cryptsetup loopaesOpen <device> <name> [--key-size 128] --key-file <key-file>

   If you are using GPG encrypted keyfile
     gpg --decrypt <key-file> | cryptsetup loopaesOpen --key-file=- <device> <name>

   Do not forget to specify key size. Other ciphers than AES should work but were
   not tested. Version and hash is automatically detected according to number
   of lines in key file.

   Please note that loopAES dm-crypt mode is provided for compatibility reasons
   (so you do not need to patch kernel and util-linux to map existing volumes)
   but is is not, and never will be, optimized for speed.
   It is experimental feature for now.

 * WARNING: This is the last cryptsetup release which supports library with
            old API (using struct crypt_options).
            These calls are deprecated since 1.1.0 and AFAIK no application
            is using it in recent distros. Removing compatible code will allow
            new features to be implemented easily.

Other changes
 * Increase libcryptsetup version (loopAES change), still fully backward compatible.
 * Fixes static build (--disable-static-cryptsetup now works properly).
 * Supports secure data flag for device-mapper iotcl (will be in 2.6.39,
   forcing kernel to wipe all ioctl buffers with possible key data).
   To enable this flag you need new device-mapper library, in LVM2 2.02.84.
 * Add copyright texts into some files and adds GPL exception allowing
   to distribute resulting binaries linked with OpenSSL.
 * Update FAQ.
 * Fix message when locking memory fails.
 * Fix luksAddKey return code if master key is used.
 * Update some text files in distributions.
 * Add docs directory with Release Notes archive.
 * Do not hardcode loopback device name in tests, use internal loopback library.

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