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Editing: v2.4.0-ReleaseNotes
Cryptsetup 2.4.0 Release Notes ============================== Stable release with new features and bug fixes. This version introduces support for external libraries (plugins) for handling LUKS2 token objects. Changes since version 2.3.6 ~~~~~~~~~~~~~~~~~~~~~~~~~~~ * External LUKS token plugins A LUKS2 token is an object that can describe how to get a passphrase to unlock a particular keyslot. The generic metadata format is part of the LUKS2 specification. Cryptsetup 2.4 adds the possibility to implement token handlers in external libraries (possibly provided by other projects). A token library allows cryptsetup to understand metadata and provide basic operations. Currently external tokens may be used to unlock keyslots for following CLI actions: open (luksOpen), refresh (open --refresh), resize and dump (prints token specific content). LUKS2 devices cannot be resumed (luksResume action) via tokens yet. Support for resume and other actions will be added later. The library now provides an interface that automatically tries to load an external library for a token object in LUKS2 metadata. Token libraries should be installed in the cryptsetup subdirectory (usually /lib*/cryptsetup). This path is configurable through --with-luks2-external-tokens-path configure option. The external plugin loading can be compiled entirely out if --disable-external-tokens configure option is used. The external token interface can also be disabled runtime on the command line by --disable-external-tokens cryptsetup switch or by calling crypt_token_external_disable() API function. The name of the loaded token library is determined from the JSON LUKS metadata token object type. For example, "ssh" token will load library "libcryptsetup-token-ssh.so". External projects can use this interface to handle specific hardware without introducing additional dependencies to libcryptsetup core. As of cryptsetup 2.4.0 release systemd project already merged upstream native cryptsetup token handler for its systemd-tpm2 LUKS2 token released originally in systemd-v248. The token can be created using systemd-cryptenroll utility and devices may be manipulated either by systemd-cryptsetup cli or by cryptsetup for actions listed above. Other tokens like systemd-fido2 and systemd-pkcs11 are currently in-review. * Experimental SSH token As a demonstration of the external LUKS2 token interface, a new SSH token handler and cryptsetup-ssh utility is now provided and compiled by default. Crypsetup SSH token allows using remote keyfile through SSH protocol (it will authenticate through SSH certificates). You can disable the build of this token library with --disable-ssh-token configure option. To configure the token metadata, you need cryptsetup-ssh utility. Activation of the device is then performed by the cryptsetup utility. Example (how to activate LUKS2 through remote keyfile): - configure existing LUKS2 device with keyslot activated by a keyfile # cryptsetup luksAddKey <device> keyfile --key-slot 2 - store that keyfile on a remote system accessible through SSH - configure SSH to use certificate for authentication - add a LUKS2 token with cryptsetup-ssh utility: # cryptsetup-ssh add <device>1 --key-slot 2 \ --ssh-server test-vm \ --ssh-user test \ --ssh-path /home/test/keyfile \ --ssh-keypath /home/test/.ssh/test_rsa_key - you should see token metadata now with "cryptsetup luksDump ..." ... Tokens: 0: ssh ssh_server: test-vm ssh_user: test ssh_path: /home/test/keyfile ssh_key_path: /home/test/.ssh/test_rsa_key Keyslot: 2 - activation now should be automatic # cryptsetup open <device> test --verbose SSH token initiating ssh session. Key slot 2 unlocked. Command successful. - to remove a token, you can use "cryptsetup token remove" command (no plugin library required) Please note SSH token is just demonstration of plugin interface API, it is an EXPERIMENTAL feature. * Add cryptsetup --token-type parameter. It restricts token type to the parameter value in case no specific token-id is selected. * Support for token based activation with PIN. If specific token requires PIN to unlock keyslot passphrase and --token-only parameter was used cryptsetup asks for additional token PIN. * Respect keyslot priority with token-based activation. * Default LUKS2 PBKDF is now Argon2id Cryptsetup LUKS2 was using Argon2 while there were two versions, data-independent (Argon2i) suitable for the KDF use case and Argon2d (data-dependent). Later Argon2id was introduced as a new mandatory algorithm. We switched the password-based key derivation algorithms following the latest version of Argon2 RFC draft (https://datatracker.ietf.org/doc/draft-irtf-cfrg-argon2/) to Argon2id (from Argon2i) as it is the mandatory and primary version of the Argon2 algorithm. There is no need to modify older containers; the main reason is that RFC makes Argon2id the primary variant, while Argon2i subvariant is only optional. Argon2id provides better protection to side-channel attacks while still providing protection to time-memory tradeoffs. We will switch to OpenSSL implementation once it is available. With a crystal ball as a reference, it could happen early in OpenSSL 3.1 release. Watch https://github.com/openssl/openssl/issues/4091. * Increase minimal memory cost for Argon2 benchmark to 64MiB. This patch increases the benchmarking value to 64 MiB (as minimal suggested values in Argon2 RFC). For compatibility reasons, we still allow older limits if set by a parameter. NOTE: Argon2 RFC draft defines suggested parameters for disk encryption, but the LUKS2 approach is slightly different. We need to provide platform-independent values. The values in the draft expect 64bit systems (suggesting using 6 GiB of RAM). In comparison, we need to provide compatibility with all 32bit systems, so allocating more than 4GiB memory is not an option for LUKS2. The maximal limit in LUKS2 stays for 4 GiB, and by default LUKS2 PBKDF benchmarking sets maximum to 1 GIB, preferring an increase of CPU cost while running benchmark * Autodetect optimal encryption sector size on LUKS2 format. While the support for larger encryption sectors is supported for several releases, it required an additional parameter. Code now uses automatic detection of 4096-bytes native sector devices and automatically enables 4096-bytes encryption size for LUKS2. If no setor size option is used, sector size is detected automatically by cryptsetup. For libcryptsetup API, autodetection happens once you specify sector_size to 0. NOTE: crypt_format() function runs autodetection ONLY if you recompile your application to the new API symbol version. For backward compatibility, older applications ignore this parameter. * Use VeraCrypt option by default and add --disable-veracrypt option. While TrueCrypt is no longer developed and supported since 2014, VeraCrypt devices (a successor of TrueCrypt) are much more used today. Default is now to support VeraCrypt format (in addition to TrueCrypt), making the --veracrypt option obsolete (ignored as it is the default). If you need to disable VeraCrypt support, use the new option --disable-veracrypt. This option increases the time to recognize wrong passwords because some VeraCrypt modes use a high PBKDF2 iteration count, and the code must try all variants. This could be limited by using --hash and --cipher options mentioned below. * Support --hash and --cipher to limit opening time for TCRYPT type If a user knows which particular PBKDF2 hash or cipher is used for TrueCrypt/VeraCrypt container, TCRYPT format now supports --hash and --cipher option. Note the value means substring (all cipher chains containing the cipher substring are tried). For example, you can use # cryptsetup tcryptDump --hash sha512 <container> Note: to speed up the scan, the hash option (used for PBKDF)2 matters. Cipher variants are scanned very quickly. Use with care. It can reveal some sensitive attributes of the container! * Fixed default OpenSSL crypt backend support for OpenSSL3. For OpenSSL version 3, we need to load legacy provider for older hash and ciphers. For example, RIPEMD160 and Whirlpool hash algorithms are no longer available by default. NOTE: the plain format still uses RIPEMD160 for password hashing by default. Changing the default would cause incompatibilities for many old systems. Nevertheless, such a change will be needed very soon. * integritysetup: add integrity-recalculate-reset flag. The new dm-integrity option in kernel 5.13 can restart recalculation from the beginning of the device. It can be used to change the integrity checksum function. New integritysetup --integrity-recalculate-reset option is added to integritysetup, and CRYPT_ACTIVATE_RECALCULATE_RESET flag to API. * cryptsetup: retains keyslot number in luksChangeKey for LUKS2. In LUKS1, any change in keyslot means keyslot number change. In LUKS2, we can retain the keyslot number. Now luksKeyChange and crypt_keyslot_change_by_passphrase() API retains keyslot number for LUKS2 by default. * Fix cryptsetup resize using LUKS2 tokens. Fix a bug where cryptsetup needlessly asked for a passphrase even though the volume key was already unlocked via LUKS2 token. * Add close --deferred and --cancel-deferred options. All command-line utilities now understand deferred options for the close command. Deferred close means that the device is removed automagically after the last user closed the device. Cancel deferred means to cancel this operation (so the device remains active even if there a no longer active users). CRYPT_DEACTIVATE_DEFERRED and CRYPT_DEACTIVATE_DEFERRED_CANCEL flags are now available for API. * Rewritten command-line option parsing to avoid libpopt arguments memory leaks. Note: some distributions use patched lipopt that still leaks memory inside internal code (see Debian bug 941814). * Add --test-args option. New --test-args option can be used for syntax checking for valid command-line arguments with no actions performed. Note that it cannot detect unknown algorithm names and similar where we need call API functions. * veritysetup: add --root-hash-file option Allow passing the root hash via a file, rather than verbatim on the command line, for the open, verify, and format actions. * libcryptsetup C API extensions (see libcryptsetup.h for details) - crypt_logf - a printf like log function - crypt_dump_json - dump LUKS2 metadata in JSON format - crypt_header_is_detached - check if context use detached header - crypt_token_max - get maximal tokens number - crypt_token_external_path - get path for plugins (or NULL) - crypt_token_external_disable - disable runtime support for plugins - crypt_activate_by_token_pin - activate by token with additional PIN - crypt_reencrypt_run - fixed API for deprecated crypt_reencrypt The token plugin library interface cosists from these versioned exported symbols (for details see header file and SSH token example): cryptsetup_token_open cryptsetup_token_open_pin cryptsetup_token_buffer_free cryptsetup_token_validate cryptsetup_token_dump cryptsetup_token_version Since version 2.4 libcryptsetup uses exact symbol versioning Newly introduced functions have CRYPTSETUP_2.4 namespace (the old symbol always used CRYPTSETUP_2.0). There is no change in soname (the library is backward compatible). * Many fixes and additions to documentation and man pages.
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