Provided by: cryptsetup-bin_2.7.2-2ubuntu1_amd64 bug

NAME

       cryptsetup-luksConvertKey - converts an existing LUKS2 keyslot to new PBKDF parameters

SYNOPSIS

       cryptsetup luksConvertKey [<options>] <device>

DESCRIPTION

       Converts an existing LUKS2 keyslot to new PBKDF parameters. The passphrase for keyslot to
       be converted must be supplied interactively or via --key-file. If no --pbkdf parameters
       are specified LUKS2 default PBKDF values will apply.

       If a keyslot is specified (via --key-slot), the passphrase for that keyslot must be given.
       If no keyslot is specified and there is still a free keyslot, then the new parameters will
       be put into a free keyslot before the keyslot containing the old parameters is purged. If
       there is no free keyslot, then the keyslot with the old parameters is overwritten
       directly.

       WARNING: If a keyslot is overwritten, a media failure during this operation can cause the
       overwrite to fail after the old parameters have been wiped and make the LUKS container
       inaccessible.

       <options> can be [--key-file, --keyfile-offset, --keyfile-size, --key-slot, --hash,
       --header, --disable-locks, --iter-time, --pbkdf, --pbkdf-force-iterations, --pbkdf-memory,
       --pbkdf-parallel, --keyslot-cipher, --keyslot-key-size, --timeout, --verify-passphrase].

OPTIONS

       --batch-mode, -q
           Suppresses all confirmation questions. Use with care!

           If the --verify-passphrase option is not specified, this option also switches off the
           passphrase verification.

       --debug or --debug-json
           Run in debug mode with full diagnostic logs. Debug output lines are always prefixed by
           #.

           If --debug-json is used, additional LUKS2 JSON data structures are printed.

       --disable-locks
           Disable lock protection for metadata on disk. This option is valid only for LUKS2 and
           ignored for other formats.

           WARNING: Do not use this option unless you run cryptsetup in a restricted environment
           where locking is impossible to perform (where /run directory cannot be used).

       --force-password
           Do not use password quality checking for new LUKS passwords.

           This option is ignored if cryptsetup is built without password quality checking
           support.

           For more info about password quality check, see the manual page for pwquality.conf(5)
           and passwdqc.conf(5).

       --hash, -h <hash-spec>
           The specified hash is used for PBKDF2 and AF splitter.

       --header <device or file storing the LUKS header>
           Use a detached (separated) metadata device or file where the LUKS header is stored.
           This option allows one to store ciphertext and LUKS header on different devices.

           For commands that change the LUKS header (e.g. luksAddKey), specify the device or file
           with the LUKS header directly as the LUKS device.

       --help, -?
           Show help text and default parameters.

       --iter-time, -i <number of milliseconds>
           The number of milliseconds to spend with PBKDF passphrase processing. Specifying 0 as
           parameter selects the compiled-in default.

       --key-file, -d name
           Read the passphrase from file.

           If the name given is "-", then the passphrase will be read from stdin. In this case,
           reading will not stop at newline characters.

           See section NOTES ON PASSPHRASE PROCESSING in cryptsetup(8) for more information.

       --keyfile-offset value
           Skip value bytes at the beginning of the key file.

       --keyfile-size, -l value
           Read a maximum of value bytes from the key file. The default is to read the whole file
           up to the compiled-in maximum that can be queried with --help. Supplying more data
           than the compiled-in maximum aborts the operation.

           This option is useful to cut trailing newlines, for example. If --keyfile-offset is
           also given, the size count starts after the offset.

       --key-slot, -S <0-N>
           For LUKS operations that add key material, this option allows you to specify which key
           slot is selected for the new key.

           The maximum number of key slots depends on the LUKS version. LUKS1 can have up to 8
           key slots. LUKS2 can have up to 32 key slots based on key slot area size and key size,
           but a valid key slot ID can always be between 0 and 31 for LUKS2.

       --keyslot-cipher <cipher-spec>
           This option can be used to set specific cipher encryption for the LUKS2 keyslot area.

       --keyslot-key-size <bits>
           This option can be used to set specific key size for the LUKS2 keyslot area.

       --new-keyfile-offset value
           Skip value bytes at the start when adding a new passphrase from key file.

       --new-keyfile-size value
           Read a maximum of value bytes when adding a new passphrase from key file. The default
           is to read the whole file up to the compiled-in maximum length that can be queried
           with --help. Supplying more than the compiled in maximum aborts the operation. When
           --new-keyfile-offset is also given, reading starts after the offset.

       --pbkdf <PBKDF spec>
           Set Password-Based Key Derivation Function (PBKDF) algorithm for LUKS keyslot. The
           PBKDF can be: pbkdf2 (for PBKDF2 according to RFC2898), argon2i for Argon2i or
           argon2id for Argon2id (see Argon2 <https://www.cryptolux.org/index.php/Argon2> for
           more info).

           For LUKS1, only PBKDF2 is accepted (no need to use this option). The default PBKDF for
           LUKS2 is set during compilation time and is available in cryptsetup --help output.

           A PBKDF is used for increasing dictionary and brute-force attack cost for keyslot
           passwords. The parameters can be time, memory and parallel cost.

           For PBKDF2, only time cost (number of iterations) applies. For Argon2i/id, there is
           also memory cost (memory required during the process of key derivation) and parallel
           cost (number of threads that run in parallel during the key derivation.

           Note that increasing memory cost also increases time, so the final parameter values
           are measured by a benchmark. The benchmark tries to find iteration time (--iter-time)
           with required memory cost --pbkdf-memory. If it is not possible, the memory cost is
           decreased as well. The parallel cost --pbkdf-parallel is constant and is checked
           against available CPU cores.

           You can see all PBKDF parameters for particular LUKS2 keyslot with
           cryptsetup-luksDump(8) command.

           NOTE: If you do not want to use benchmark and want to specify all parameters directly,
           use --pbkdf-force-iterations with --pbkdf-memory and --pbkdf-parallel. This will
           override the values without benchmarking. Note it can cause extremely long unlocking
           time or cause out-of-memory conditions with unconditional process termination. Use
           only in specific cases, for example, if you know that the formatted device will be
           used on some small embedded system.

           MINIMAL AND MAXIMAL PBKDF COSTS: For PBKDF2, the minimum iteration count is 1000 and
           maximum is 4294967295 (maximum for 32bit unsigned integer). Memory and parallel costs
           are unused for PBKDF2. For Argon2i and Argon2id, minimum iteration count (CPU cost) is
           4 and maximum is 4294967295 (maximum for 32bit unsigned integer). Minimum memory cost
           is 32 KiB and maximum is 4 GiB. (Limited by addressable memory on some CPU platforms.)
           If the memory cost parameter is benchmarked (not specified by a parameter) it is
           always in range from 64 MiB to 1 GiB. The parallel cost minimum is 1 and maximum 4 (if
           enough CPUs cores are available, otherwise it is decreased).

       --pbkdf-force-iterations <num>
           Avoid PBKDF benchmark and set time cost (iterations) directly. It can be used for
           LUKS/LUKS2 device only. See --pbkdf option for more info.

       --pbkdf-memory <number>
           Set the memory cost for PBKDF (for Argon2i/id the number represents kilobytes). Note
           that it is maximal value, PBKDF benchmark or available physical memory can decrease
           it. This option is not available for PBKDF2.

       --pbkdf-parallel <number>
           Set the parallel cost for PBKDF (number of threads, up to 4). Note that it is maximal
           value, it is decreased automatically if CPU online count is lower. This option is not
           available for PBKDF2.

       --timeout, -t <number of seconds>
           The number of seconds to wait before timeout on passphrase input via terminal. It is
           relevant every time a passphrase is asked. It has no effect if used in conjunction
           with --key-file.

           This option is useful when the system should not stall if the user does not input a
           passphrase, e.g. during boot. The default is a value of 0 seconds, which means to wait
           forever.

       --usage
           Show short option help.

       --verify-passphrase, -y
           When interactively asking for a passphrase, ask for it twice and complain if both
           inputs do not match. Ignored on input from file or stdin.

       --version, -V
           Show the program version.

REPORTING BUGS

       Report bugs at cryptsetup mailing list <cryptsetup@lists.linux.dev> or in Issues project
       section <https://gitlab.com/cryptsetup/cryptsetup/-/issues/new>.

       Please attach output of the failed command with --debug option added.

SEE ALSO

       Cryptsetup FAQ <https://gitlab.com/cryptsetup/cryptsetup/wikis/FrequentlyAskedQuestions>

       cryptsetup(8), integritysetup(8) and veritysetup(8)

CRYPTSETUP

       Part of cryptsetup project <https://gitlab.com/cryptsetup/cryptsetup/>.