table of contents
CRYPTSETUP-LUKSDUMP(8) | Maintenance Commands | CRYPTSETUP-LUKSDUMP(8) |
NAME¶
cryptsetup-luksDump - dump the header information of a LUKS device
SYNOPSIS¶
cryptsetup luksDump [<options>] <device>
DESCRIPTION¶
Dump the header information of a LUKS device.
If the --dump-volume-key option is used, the LUKS device volume key is dumped instead of the keyslot info. Together with the --volume-key-file option, volume key is dumped to a file instead of standard output. Beware that the volume key cannot be changed without reencryption and can be used to decrypt the data stored in the LUKS container without a passphrase and even without the LUKS header. This means that if the volume key is compromised, the whole device has to be erased or reencrypted to prevent further access. Use this option carefully.
To dump the volume key, a passphrase has to be supplied, either interactively or via --key-file.
To dump unbound key (LUKS2 format only), --unbound parameter, specific --key-slot id and proper passphrase has to be supplied, either interactively or via --key-file. Optional --volume-key-file parameter enables unbound keyslot dump to a file.
To dump LUKS2 JSON metadata (without basic header information like UUID) use --dump-json-metadata option.
<options> can be [--dump-volume-key, --dump-json-metadata, --key-file, --keyfile-offset, --keyfile-size, --header, --disable-locks, --volume-key-file, --type, --unbound, --key-slot, --timeout].
WARNING: If --dump-volume-key is used with --key-file and the argument to --key-file is '-', no validation question will be asked and no warning given.
OPTIONS¶
--type <device-type>
--key-file, -d name
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
--keyfile-size, -l value
This option is useful to cut trailing newlines, for example. If --keyfile-offset is also given, the size count starts after the offset.
--volume-key-file, --master-key-file (OBSOLETE alias)
--dump-json-metadata
--dump-volume-key, --dump-master-key (OBSOLETE alias)
--key-slot, -S <0-N>
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.
--timeout, -t <number of seconds>
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.
--header <device or file storing the LUKS header>
For commands that change the LUKS header (e.g. luksAddKey), specify the device or file with the LUKS header directly as the LUKS device.
--disable-locks
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).
--unbound
--batch-mode, -q
If the --verify-passphrase option is not specified, this option also switches off the passphrase verification.
--debug or --debug-json
If --debug-json is used, additional LUKS2 JSON data structures are printed.
--version, -V
--usage
--help, -?
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¶
Part of cryptsetup project <https://gitlab.com/cryptsetup/cryptsetup/>.
2023-06-30 | cryptsetup 2.6.0 |