== OPTIONS ifdef::ACTION_REENCRYPT[] *--block-size* _value_ *(LUKS1 only)*:: Use re-encryption block size of _value_ in MiB. + Values can be between 1 and 64 MiB. endif::[] ifdef::ACTION_REENCRYPT[] *--use-directio (LUKS1 only)*:: Use direct-io (O_DIRECT) for all read/write data operations related to block device undergoing reencryption. + Useful if direct-io operations perform better than normal buffered operations (e.g. in virtual environments). endif::[] ifdef::ACTION_REENCRYPT[] *--use-fsync (LUKS1 only)*:: Use fsync call after every written block. This applies for reencryption log files as well. endif::[] ifdef::ACTION_REENCRYPT[] *--write-log (LUKS1 only)*:: Update log file after every block write. This can slow down reencryption but will minimize data loss in the case of system crash. endif::[] ifdef::ACTION_ISLUKS[] *--verbose, -v*:: Print more information on command execution. endif::[] ifdef::ACTION_OPEN,ACTION_LUKSFORMAT,ACTION_LUKSRESUME,ACTION_LUKSADDKEY,ACTION_LUKSREMOVEKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSKILLSLOT,ACTION_ISLUKS,ACTION_LUKSDUMP,ACTION_LUKSUUID,ACTION_CONVERT,ACTION_REPAIR,ACTION_REENCRYPT[] *--type *:: ifndef::ACTION_REENCRYPT[] Specifies required device type, for more info read _BASIC ACTIONS_ section in *cryptsetup*(8). endif::[] ifdef::ACTION_REENCRYPT[] Specifies required (encryption mode) or expected (other modes) LUKS format. Accepts only _luks1_ or _luks2_. endif::[] endif::[] ifdef::ACTION_OPEN,ACTION_LUKSFORMAT,ACTION_LUKSADDKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY,ACTION_TCRYPTDUMP,ACTION_BENCHMARK,ACTION_REENCRYPT[] *--hash, -h* __:: ifdef::ACTION_OPEN,ACTION_TCRYPTDUMP[] Specifies the passphrase hash. Applies to _plain_ and _loopaes_ device types only. + For _tcrypt_ device type, it restricts checked PBKDF2 variants when looking for header. endif::[] ifdef::ACTION_LUKSFORMAT[] Specifies the hash used in the LUKS key setup scheme and volume key digest. endif::[] ifndef::ACTION_REENCRYPT,ACTION_OPEN,ACTION_TCRYPTDUMP[] The specified hash is used for PBKDF2 and AF splitter. endif::[] ifdef::ACTION_REENCRYPT[] *LUKS1:* Specifies the hash used in the LUKS1 key setup scheme and volume key digest. + *NOTE*: if this parameter is not specified, default hash algorithm is always used for new LUKS1 device header. + *LUKS2:* Ignored unless new keyslot pbkdf algorithm is set to PBKDF2 (see --pbkdf). endif::[] + ifdef::ACTION_LUKSFORMAT[] The hash algorithm must provide at least 160 bits of output. Do not use a non-crypto hash like *xxhash* as this breaks security. Use _cryptsetup --help_ to show the defaults. endif::[] endif::[] ifdef::ACTION_OPEN,ACTION_LUKSFORMAT,ACTION_REENCRYPT,ACTION_TCRYPTDUMP,ACTION_BENCHMARK[] *--cipher, -c* __:: ifdef::ACTION_OPEN,ACTION_TCRYPTDUMP[] Set the cipher specification string for _plain_ device type. + For _tcrypt_ device type it restricts checked cipher chains when looking for header. endif::[] ifndef::ACTION_REENCRYPT,ACTION_OPEN,ACTION_TCRYPTDUMP[] Set the cipher specification string. endif::[] ifdef::ACTION_REENCRYPT[] *LUKS2*: Set the cipher specification string for data segment only. + *LUKS1*: Set the cipher specification string for data segment and keyslots. + *NOTE*: In encrypt mode, if cipher specification is omitted the default cipher is applied. In reencrypt mode, if no new cipher specification is requested, the existing cipher will remain in use. Unless the existing cipher was "cipher_null". In that case default cipher would be applied as in encrypt mode. endif::[] ifdef::ACTION_OPEN,ACTION_LUKSFORMAT,ACTION_REENCRYPT[] + _cryptsetup --help_ shows the compiled-in defaults. + If a hash is part of the cipher specification, then it is used as part of the IV generation. For example, ESSIV needs a hash function, while "plain64" does not and hence none is specified. + For XTS mode you can optionally set a key size of 512 bits with the -s option. Key size for XTS mode is twice that for other modes for the same security level. endif::[] endif::[] ifdef::ACTION_OPEN,ACTION_RESIZE,ACTION_LUKSFORMAT,ACTION_LUKSRESUME,ACTION_LUKSADDKEY,ACTION_LUKSREMOVEKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY,ACTION_LUKSKILLSLOT,ACTION_REPAIR,ACTION_TCRYPTDUMP,ACTION_REENCRYPT[] *--verify-passphrase, -y*:: When interactively asking for a passphrase, ask for it twice and complain if both inputs do not match. ifdef::ACTION_OPEN[] Advised when creating a _plain_ type mapping for the first time. endif::[] Ignored on input from file or stdin. endif::[] ifdef::ACTION_OPEN,ACTION_RESIZE,ACTION_LUKSFORMAT,ACTION_LUKSRESUME,ACTION_LUKSADDKEY,ACTION_LUKSREMOVEKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY,ACTION_LUKSKILLSLOT,ACTION_LUKSDUMP,ACTION_TCRYPTDUMP,ACTION_REENCRYPT,ACTION_REPAIR,ACTION_BITLKDUMP[] *--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. + ifdef::ACTION_LUKSADDKEY,ACTION_LUKSCHANGEKEY[] The passphrase supplied via --key-file is always the passphrase for existing keyslot requested by the command. + If you want to set a new passphrase via key file, you have to use a positional argument or parameter --new-keyfile. + endif::[] ifdef::ACTION_OPEN[] *NOTE:* With _plain_ device type, the passphrase obtained via --key-file option is passed directly in dm-crypt. Unlike the interactive mode (stdin) where digest (--hash option) of the passphrase is passed in dm-crypt instead. + endif::[] ifndef::ACTION_REENCRYPT[] See section _NOTES ON PASSPHRASE PROCESSING_ in *cryptsetup*(8) for more information. endif::[] ifdef::ACTION_REENCRYPT[] *WARNING:* --key-file option can be used only if there is only one active keyslot, or alternatively, also if --key-slot option is specified (then all other keyslots will be disabled in new LUKS device). + If this option is not used, cryptsetup will ask for all active keyslot passphrases. endif::[] endif::[] ifdef::ACTION_OPEN,ACTION_RESIZE,ACTION_LUKSFORMAT,ACTION_LUKSRESUME,ACTION_LUKSADDKEY,ACTION_LUKSREMOVEKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY,ACTION_LUKSKILLSLOT,ACTION_LUKSDUMP,ACTION_REENCRYPT,ACTION_REPAIR,ACTION_BITLKDUMP[] *--keyfile-offset* _value_:: Skip _value_ bytes at the beginning of the key file. endif::[] ifdef::ACTION_OPEN,ACTION_RESIZE,ACTION_LUKSFORMAT,ACTION_LUKSRESUME,ACTION_LUKSADDKEY,ACTION_LUKSREMOVEKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY,ACTION_LUKSKILLSLOT,ACTION_LUKSDUMP,ACTION_REENCRYPT,ACTION_REPAIR,ACTION_BITLKDUMP[] *--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. endif::[] ifdef::ACTION_LUKSADDKEY[] *--new-keyfile* _name_:: Read the passphrase for a new keyslot 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. + This is alternative method to positional argument when adding new passphrase via kefile. endif::[] ifdef::ACTION_LUKSADDKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY[] *--new-keyfile-offset* _value_:: Skip _value_ bytes at the start when adding a new passphrase from key file. endif::[] ifdef::ACTION_LUKSADDKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY[] *--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. endif::[] ifdef::ACTION_OPEN,ACTION_LUKSFORMAT,ACTION_LUKSADDKEY,ACTION_LUKSDUMP,ACTION_BITLKDUMP,ACTION_REENCRYPT[] *--volume-key-file, --master-key-file (OBSOLETE alias)*:: ifndef::ACTION_REENCRYPT[] Use a volume key stored in a file. endif::[] ifdef::ACTION_FORMAT[] + This allows creating a LUKS header with this specific volume key. If the volume key was taken from an existing LUKS header and all other parameters are the same, then the new header decrypts the data encrypted with the header the volume key was taken from. + endif::[] ifdef::ACTION_LUKSDUMP,ACTION_BITLKDUMP[] The volume key is stored in a file instead of being printed out to standard output. + endif::[] ifdef::ACTION_LUKSADDKEY[] This allows adding a new keyslot without having to know passphrase to existing one. It may be also used when no keyslot is active. + endif::[] ifdef::ACTION_OPEN[] This allows one to open _luks_ and _bitlk_ device types without giving a passphrase. + endif::[] ifdef::ACTION_REENCRYPT[] Use (set) new volume key stored in a file. + endif::[] ifdef::ACTION_LUKSFORMAT,ACTION_LUKSADDKEY,ACTION_REENCRYPT[] *WARNING:* If you create your own volume key, you need to make sure to do it right. Otherwise, you can end up with a low-entropy or otherwise partially predictable volume key which will compromise security. endif::[] endif::[] ifdef::ACTION_LUKSDUMP[] *--dump-json-metadata*:: For _luksDump_ (LUKS2 only) this option prints content of LUKS2 header JSON metadata area. endif::[] ifdef::ACTION_LUKSDUMP,ACTION_TCRYPTDUMP,ACTION_BITLKDUMP[] *--dump-volume-key, --dump-master-key (OBSOLETE alias)*:: Print the volume key in the displayed information. Use with care, as the volume key can be used to bypass the passphrases, see also option --volume-key-file. endif::[] ifdef::ACTION_TOKEN[] *--json-file*:: Read token JSON from a file or write token to it. --json-file=- reads JSON from standard input or writes it to standard output respectively. endif::[] ifdef::ACTION_TOKEN[] *--token-replace*:: Replace an existing token when adding or importing a token with the --token-id option. endif::[] ifdef::ACTION_LUKSFORMAT,ACTION_REENCRYPT[] *--use-random*:: *--use-urandom*:: ifdef::ACTION_REENCRYPT[] Define which kernel random number generator will be used to create the volume key. endif::[] ifndef::ACTION_REENCRYPT[] For _luksFormat_ these options define which kernel random number generator will be used to create the volume key (which is a long-term key). + See *NOTES ON RANDOM NUMBER GENERATORS* in *cryptsetup*(8) for more information. Use _cryptsetup --help_ to show the compiled-in default random number generator. + *WARNING:* In a low-entropy situation (e.g. in an embedded system) and older kernels, both selections are problematic. Using /dev/urandom can lead to weak keys. Using /dev/random can block a long time, potentially forever, if not enough entropy can be harvested by the kernel. endif::[] endif::[] ifdef::ACTION_REENCRYPT[] *--keep-key*:: *LUKS2*: Do not change effective volume key and change other parameters provided it is requested. + *LUKS1*: Reencrypt only the LUKS1 header and keyslots. Skips data in-place reencryption. endif::[] ifdef::ACTION_OPEN,ACTION_RESIZE,ACTION_LUKSFORMAT,ACTION_LUKSADDKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY,ACTION_LUKSDUMP,ACTION_LUKSRESUME,ACTION_TOKEN,ACTION_CONFIG,ACTION_TOKEN,ACTION_REPAIR,ACTION_REENCRYPT[] *--key-slot, -S <0-N>*:: ifdef::ACTION_LUKSADDKEY[] When used together with parameter --new-key-slot this option allows you to specify which key slot is selected for unlocking volume key. + *NOTE:* This option is ignored if existing volume key gets unlocked via LUKS2 token (--token-id, --token-type or --token-only parameters) or when volume key is provided directly via --volume-key-file parameter. + *NOTE:* To maintain backward compatibility, without --new-key-slot parameter, this option allows you to specify which key slot is selected for the new key. endif::[] ifndef::ACTION_OPEN,ACTION_LUKSADDKEY[] For LUKS operations that add key material, this option allows you to specify which key slot is selected for the new key. endif::[] ifdef::ACTION_OPEN[] This option selects a specific key-slot to compare the passphrase against. If the given passphrase would only match a different key-slot, the operation fails. endif::[] + ifdef::ACTION_REENCRYPT[] For reencryption mode it selects specific keyslot (and passphrase) that can be used to unlock new volume key. If used all other keyslots get removed after reencryption operation is finished. + endif::[] 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. endif::[] ifdef::ACTION_LUKSADDKEY[] *--new-key-slot <0-N>*:: This option allows you to specify which key slot is selected for the new key. + *NOTE:* When used this option affects --key-slot option. + 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. endif::[] ifdef::ACTION_OPEN,ACTION_LUKSFORMAT,ACTION_REENCRYPT,ACTION_BENCHMARK,ACTION_LUKSADDKEY[] *--key-size, -s* _bits_:: ifndef::ACTION_LUKSADDKEY[] Sets key size in _bits_. The argument has to be a multiple of 8. The possible key-sizes are limited by the cipher and mode used. + See /proc/crypto for more information. Note that key-size in /proc/crypto is stated in bytes. + endif::[] ifdef::ACTION_LUKSADDKEY[] Provide volume key size in _bits_. The argument has to be a multiple of 8. + This option is required when parameter --volume-key-file is used to provide current volume key. Also, it is used when new unbound keyslot is created by specifying --unbound parameter. endif::[] ifdef::ACTION_OPEN[] This option can be used for _plain_ device type only. endif::[] ifndef::ACTION_REENCRYPT,ACTION_OPEN,ACTION_LUKSADDKEY[] This option can be used for _open --type plain_ or _luksFormat_. All other LUKS actions will use the key-size specified in the LUKS header. Use _cryptsetup --help_ to show the compiled-in defaults. endif::[] ifdef::ACTION_REENCRYPT[] *LUKS1*: If you are increasing key size, there must be enough space in the LUKS header for enlarged keyslots (data offset must be large enough) or reencryption cannot be performed. + If there is not enough space for keyslots with new key size, you can destructively shrink device with --reduce-device-size option. endif::[] endif::[] ifdef::ACTION_OPEN,ACTION_RESIZE[] *--size, -b *:: Set the size of the device in sectors of 512 bytes. ifdef::ACTION_OPEN[] Usable only with _plain_ device type. endif::[] endif::[] ifdef::ACTION_OPEN,ACTION_LUKSFORMAT,ACTION_REENCRYPT[] *--offset, -o *:: Start offset in the backend device in 512-byte sectors. ifdef::ACTION_OPEN[] This option is only relevant with plain or loopaes device types. endif::[] ifdef::ACTION_REENCRYPT[] This option is only relevant for the encrypt mode. endif::[] + ifndef::ACTION_OPEN[] The --offset option sets the data offset (payload) of data device and must be aligned to 4096-byte sectors (must be multiple of 8). This option cannot be combined with --align-payload option. endif::[] endif::[] ifdef::ACTION_OPEN[] *--skip, -p *:: Start offset used in IV calculation in 512-byte sectors (how many sectors of the encrypted data to skip at the beginning). This option is only relevant with plain or loopaes device types. + Hence, if --offset _n_, and --skip _s_, sector _n_ (the first sector of the encrypted device) will get a sector number of _s_ for the IV calculation. endif::[] ifdef::ACTION_OPEN,ACTION_REENCRYPT,ACTION_RESIZE[] *--device-size* _size[units]_:: ifndef::ACTION_RESIZE[] Instead of real device size, use specified value. endif::[] ifdef::ACTION_RESIZE[] Sets new size of the device. If unset real device size is used. endif::[] ifdef::ACTION_OPEN[] Usable only with _plain_ device type. endif::[] ifdef::ACTION_REENCRYPT[] It means that only specified area (from the start of the device to the specified size) will be reencrypted. + *WARNING:* This is destructive operation. Data beyond --device-size limit may be lost after operation gets finished. endif::[] + If no unit suffix is specified, the size is in bytes. + Unit suffix can be S for 512 byte sectors, K/M/G/T (or KiB,MiB,GiB,TiB) for units with 1024 base or KB/MB/GB/TB for 1000 base (SI scale). endif::[] ifdef::ACTION_OPEN[] *--readonly, -r*:: set up a read-only mapping. endif::[] ifdef::ACTION_OPEN[] *--shared*:: Creates an additional mapping for one common ciphertext device. Arbitrary mappings are supported. This option is only relevant for the _plain_ device type. Use --offset, --size and --skip to specify the mapped area. endif::[] ifdef::ACTION_LUKSFORMAT,ACTION_LUKSADDKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY,ACTION_REENCRYPT,ACTION_BENCHMARK[] *--pbkdf *:: 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 https://www.cryptolux.org/index.php/Argon2[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. 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). endif::[] ifdef::ACTION_LUKSFORMAT,ACTION_LUKSADDKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY,ACTION_REENCRYPT,ACTION_BENCHMARK[] *--iter-time, -i *:: ifndef::ACTION_REENCRYPT[] The number of milliseconds to spend with PBKDF passphrase processing. Specifying 0 as parameter selects the compiled-in default. endif::[] ifdef::ACTION_REENCRYPT[] The number of milliseconds to spend with PBKDF passphrase processing for the new LUKS header. endif::[] endif::[] ifdef::ACTION_LUKSFORMAT,ACTION_LUKSADDKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY,ACTION_REENCRYPT,ACTION_BENCHMARK[] *--pbkdf-memory *:: 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. endif::[] ifdef::ACTION_LUKSFORMAT,ACTION_LUKSADDKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY,ACTION_REENCRYPT,ACTION_BENCHMARK[] *--pbkdf-parallel *:: 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. endif::[] ifdef::ACTION_LUKSFORMAT,ACTION_LUKSADDKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY,ACTION_REENCRYPT[] *--pbkdf-force-iterations *:: Avoid PBKDF benchmark and set time cost (iterations) directly. It can be used for LUKS/LUKS2 device only. See _--pbkdf_ option for more info. endif::[] ifdef::ACTION_LUKSFORMAT,ACTION_REENCRYPT[] *--progress-frequency* _seconds_:: ifndef::ACTION_REENCRYPT[] Print separate line every _seconds_ with wipe progress. endif::[] ifdef::ACTION_REENCRYPT[] Print separate line every _seconds_ with reencryption progress. endif::[] endif::[] ifdef::ACTION_LUKSFORMAT,ACTION_REENCRYPT[] *--progress-json*:: Prints progress data in JSON format suitable mostly for machine processing. It prints separate line every half second (or based on _--progress-frequency_ value). The JSON output looks as follows during progress (except it's compact single line): + .... { "device":"/dev/sda" // backing device or file "device_bytes":"8192", // bytes of I/O so far "device_size":"44040192", // total bytes of I/O to go "speed":"126877696", // calculated speed in bytes per second (based on progress so far) "eta_ms":"2520012" // estimated time to finish an operation in milliseconds "time_ms":"5561235" // total time spent in IO operation in milliseconds } .... + Note on numbers in JSON output: Due to JSON parsers limitations all numbers are represented in a string format due to need of full 64bit unsigned integers. endif::[] ifdef::ACTION_OPEN,ACTION_LUKSFORMAT,ACTION_LUKSADDKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY,ACTION_LUKSREMOVEKEY,ACTION_LUKSKILLSLOT,ACTION_LUKSDUMP,ACTION_REENCRYPT,ACTION_REPAIR,ACTION_LUKSRESUME,ACTION_RESIZE,ACTION_TCRYPTDUMP,ACTION_BITLKDUMP[] *--timeout, -t *:: 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. endif::[] ifdef::ACTION_OPEN,ACTION_LUKSRESUME,ACTION_REENCRYPT[] *--tries, -T*:: How often the input of the passphrase shall be retried. The default is 3 tries. endif::[] ifdef::ACTION_LUKSFORMAT,ACTION_REENCRYPT[] *--align-payload *:: Align payload at a boundary of _value_ 512-byte sectors. + If not specified, cryptsetup tries to use the topology info provided by the kernel for the underlying device to get the optimal alignment. If not available (or the calculated value is a multiple of the default) data is by default aligned to a 1MiB boundary (i.e. 2048 512-byte sectors). + For a detached LUKS header, this option specifies the offset on the data device. See also the --header option. + *WARNING:* This option is DEPRECATED and has often unexpected impact to the data offset and keyslot area size (for LUKS2) due to the complex rounding. For fixed data device offset use _--offset_ option instead. endif::[] ifdef::ACTION_LUKSFORMAT,ACTION_LUKSUUID,ACTION_REENCRYPT[] *--uuid *:: ifndef::ACTION_REENCRYPT[] Use the provided _UUID_ for the _luksFormat_ command instead of generating a new one. Changes the existing _UUID_ when used with the _luksUUID_ command. + endif::[] ifdef::ACTION_REENCRYPT[] When used in encryption mode use the provided _UUID_ for the new LUKS header instead of generating a new one. + *LUKS1 (only in decryption mode)*: To find out what _UUID_ to pass look for temporary files LUKS-_UUID_.[|log|org|new] of the interrupted decryption process. + endif::[] The _UUID_ must be provided in the standard UUID format, e.g. 12345678-1234-1234-1234-123456789abc. endif::[] ifdef::ACTION_OPEN,ACTION_REFRESH[] *--allow-discards*:: Allow the use of discard (TRIM) requests for the device. This is also not supported for LUKS2 devices with data integrity protection. + *WARNING:* This command can have a negative security impact because it can make filesystem-level operations visible on the physical device. For example, information leaking filesystem type, used space, etc. may be extractable from the physical device if the discarded blocks can be located later. If in doubt, do not use it. + A kernel version of 3.1 or later is needed. For earlier kernels, this option is ignored. endif::[] ifdef::ACTION_REFRESH,ACTION_OPEN[] *--perf-same_cpu_crypt*:: Perform encryption using the same cpu that IO was submitted on. The default is to use an unbound workqueue so that encryption work is automatically balanced between available CPUs. + *NOTE:* This option is available only for low-level dm-crypt performance tuning, use only if you need a change to default dm-crypt behaviour. Needs kernel 4.0 or later. endif::[] ifdef::ACTION_REFRESH,ACTION_OPEN[] *--perf-submit_from_crypt_cpus*:: Disable offloading writes to a separate thread after encryption. There are some situations where offloading write bios from the encryption threads to a single thread degrades performance significantly. The default is to offload write bios to the same thread. + *NOTE:* This option is available only for low-level dm-crypt performance tuning, use only if you need a change to default dm-crypt behaviour. Needs kernel 4.0 or later. endif::[] ifdef::ACTION_REFRESH,ACTION_OPEN[] *--perf-no_read_workqueue, --perf-no_write_workqueue*:: Bypass dm-crypt internal workqueue and process read or write requests synchronously. + *NOTE:* These options are available only for low-level dm-crypt performance tuning, use only if you need a change to default dm-crypt behaviour. Needs kernel 5.9 or later. endif::[] ifdef::ACTION_OPEN[] *--test-passphrase*:: Do not activate the device, just verify passphrase. The device mapping name is not mandatory if this option is used. endif::[] ifndef::ACTION_BENCHMARK,ACTION_BITLKDUMP[] *--header *:: ifndef::ACTION_OPEN[] 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. + endif::[] ifdef::ACTION_OPEN[] Specify detached (separated) metadata device or file where the header is stored. + *WARNING:* There is no check whether the ciphertext device specified actually belongs to the header given. In fact, you can specify an arbitrary device as the ciphertext device with the --header option. Use with care. endif::[] ifndef::ACTION_REENCRYPT[] ifdef::ACTION_LUKSFORMAT[] With a file name as the argument to --header, the file will be automatically created if it does not exist. See the cryptsetup FAQ for header size calculation. + The --align-payload option is taken as absolute sector alignment on ciphertext device and can be zero. endif::[] ifndef::ACTION_LUKSFORMAT,ACTION_OPEN[] For commands that change the LUKS header (e.g. _luksAddKey_), specify the device or file with the LUKS header directly as the LUKS device. endif::[] endif::[] ifdef::ACTION_REENCRYPT[] If used with --encrypt/--new option, the header file will be created (or overwritten). Use with care. + *LUKS2*: For decryption mode the option may be used to export original LUKS2 header to a detached file. The passed future file must not exist at the time of initializing the decryption operation. This frees space in head of data device so that data can be moved at original LUKS2 header location. Later on decryption operation continues as if the ordinary detached header was passed. + *WARNING:* Never put exported header file in a filesystem on top of device you are about to decrypt! It would cause a deadlock. endif::[] endif::[] ifdef::ACTION_LUKSHEADERBACKUP,ACTION_LUKSHEADERRESTORE[] *--header-backup-file *:: Specify file with header backup file. endif::[] ifdef::ACTION_REENCRYPT[] *--force-offline-reencrypt (LUKS2 only)*:: Bypass active device auto-detection and enforce offline reencryption. + This option is useful especially for reencryption of LUKS2 images put in files (auto-detection is not reliable in this scenario). + It may also help in case active device auto-detection on particular data device does not work or report errors. + *WARNING:* Use with extreme caution! This may destroy data if the device is activated and/or actively used. endif::[] ifdef::ACTION_LUKSFORMAT,ACTION_LUKSADDKEY,ACTION_LUKSCHANGEKEY,ACTION_LUKSCONVERTKEY,ACTION_REENCRYPT[] *--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)*. endif::[] ifdef::ACTION_CLOSE[] *--deferred*:: Defers device removal in _close_ command until the last user closes it. endif::[] ifdef::ACTION_CLOSE[] *--cancel-deferred*:: Removes a previously configured deferred device removal in _close_ command. endif::[] ifdef::ACTION_OPEN,ACTION_LUKSRESUME,ACTION_RESIZE,ACTION_TOKEN[] *--disable-external-tokens*:: Disable loading of plugins for external LUKS2 tokens. endif::[] ifndef::ACTION_BENCHMARK,ACTION_BITLKDUMP,ACTION_TCRYPTDUMP[] *--disable-locks*:: Disable lock protection for metadata on disk. This option is valid only for LUKS2 and ignored for other formats. + ifdef::ACTION_REENCRYPT[] *NOTE:* With locking disabled LUKS2 images in files can be fully (re)encrypted offline without need for super user privileges provided used block ciphers are available in crypto backend. + endif::[] *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). endif::[] ifdef::ACTION_OPEN,ACTION_RESIZE,ACTION_REFRESH,ACTION_LUKSFORMAT,ACTION_LUKSRESUME,ACTION_TOKEN,ACTION_REENCRYPT[] *--disable-keyring*:: Do not load volume key in kernel keyring and store it directly in the dm-crypt target instead. This option is supported only for the LUKS2 type. endif::[] ifdef::ACTION_TOKEN[] *--key-description *:: Set key description in keyring for use with _token_ command. endif::[] ifdef::ACTION_CONFIG[] *--priority *:: Set a priority for LUKS2 keyslot. The _prefer_ priority marked slots are tried before _normal_ priority. The _ignored_ priority means, that slot is never used, if not explicitly requested by _--key-slot_ option. endif::[] ifdef::ACTION_OPEN,ACTION_RESIZE,ACTION_LUKSRESUME,ACTION_TOKEN,ACTION_LUKSADDKEY[] *--token-id*:: ifndef::ACTION_TOKEN,ACTION_LUKSADDKEY[] Specify what token to use and allow token PIN prompt to take precedence over interative keyslot passphrase prompt. If omitted, all available tokens (not protected by PIN) will be checked before proceeding further with passphrase prompt. endif::[] ifdef::ACTION_LUKSADDKEY[] Specify what token to use when unlocking existing keyslot to get volume key. endif::[] ifdef::ACTION_TOKEN[] Specify token number. If omitted, first unused token id is used when adding or importing new token. endif::[] endif::[] ifdef::ACTION_LUKSADDKEY[] *--new-token-id*:: Specify what token to use to get the passphrase for a new keyslot. endif::[] ifdef::ACTION_OPEN,ACTION_RESIZE,ACTION_LUKSRESUME,ACTION_LUKSADDKEY[] *--token-only*:: ifndef::ACTION_LUKSADDKEY[] Do not proceed further with action if token based keyslot unlock failed. Without the option, action asks for passphrase to proceed further. + It allows LUKS2 tokens protected by PIN to take precedence over interactive keyslot passphrase prompt. endif::[] ifdef::ACTION_LUKSADDKEY[] Use only LUKS2 tokens to unlock existing volume key. + *NOTE*: To create a new keyslot using passphrase provided by a token use --new-token-id parameter. endif::[] endif::[] ifdef::ACTION_OPEN,ACTION_RESIZE,ACTION_LUKSRESUME,ACTION_LUKSADDKEY[] *--token-type* _type_:: ifndef::ACTION_LUKSADDKEY[] Restrict tokens eligible for operation to specific token _type_. Mostly useful when no --token-id is specified. + It allows LUKS2 _type_ tokens protected by PIN to take precedence over interactive keyslot passphrase prompt. endif::[] ifdef::ACTION_LUKSADDKEY[] Specify what token type (all _type_ tokens) to use when unlocking existing keyslot to get volume key. endif::[] endif::[] ifdef::ACTION_OPEN,ACTION_LUKSFORMAT,ACTION_REENCRYPT[] ifndef::ACTION_REENCRYPT[] *--sector-size* _bytes_:: endif::[] ifndef::ACTION_REENCRYPT[] ifdef::ACTION_OPEN[] Set encryption sector size for use with _plain_ device type. It must be power of two and in range 512 - 4096 bytes. The default mode is 512 bytes. + Note that if sector size is higher than underlying device hardware sector, using this option can increase risk on incomplete sector writes during a power fail. endif::[] ifdef::ACTION_LUKSFORMAT[] Set sector size for use with disk encryption. It must be power of two and in range 512 - 4096 bytes. This option is available only with LUKS2 format. + For LUKS2 devices it's established based on parameters provided by underlying data device. For native 4K block devices it's 4096 bytes. For 4K/512e (4K physical sector size with 512 bytes emulation) it's 4096 bytes. For drives reporting only 512 bytes block size it remains 512 bytes. If data device is regular file put in filesystem it's 4096 bytes. + Note that if sector size is higher than underlying device hardware sector and there is not integrity protection that uses data journal, using this option can increase risk on incomplete sector writes during a power fail. + If used together with _--integrity_ option and dm-integrity journal, the atomicity of writes is guaranteed in all cases (but it cost write performance - data has to be written twice). endif::[] + Increasing sector size from 512 bytes to 4096 bytes can provide better performance on most of the modern storage devices and also with some hw encryption accelerators. endif::[] ifdef::ACTION_REENCRYPT[] *--sector-size* _bytes_ *(LUKS2 only)*:: Reencrypt device with new encryption sector size enforced. + *WARNING:* Increasing encryption sector size may break hosted filesystem. Do not run reencryption with --force-offline-reencrypt if unsure what block size was filesystem formatted with. endif::[] endif::[] ifdef::ACTION_OPEN[] *--iv-large-sectors*:: Count Initialization Vector (IV) in larger sector size (if set) instead of 512 bytes sectors. This option can be used only with _plain_ device type. + *NOTE:* This option does not have any performance or security impact, use it only for accessing incompatible existing disk images from other systems that require this option. endif::[] ifdef::ACTION_OPEN,ACTION_REFRESH[] *--persistent*:: If used with LUKS2 devices and activation commands like _open_ or _refresh_, the specified activation flags are persistently written into metadata and used next time automatically even for normal activation. (No need to use cryptab or other system configuration files.) + If you need to remove a persistent flag, use _--persistent_ without the flag you want to remove (e.g. to disable persistently stored discard flag, use _--persistent_ without _--allow-discards_). + Only _--allow-discards_, _--perf-same_cpu_crypt_, _--perf-submit_from_crypt_cpus_, _--perf-no_read_workqueue_, _--perf-no_write_workqueue_ and _--integrity-no-journal_ can be stored persistently. endif::[] ifdef::ACTION_OPEN[] *--refresh*:: Refreshes an active device with new set of parameters. See *cryptsetup-refresh*(8) for more details. endif::[] ifdef::ACTION_LUKSFORMAT,ACTION_CONFIG,ACTION_REENCRYPT[] *--label