x SuSE Linux 13.1-RELEASE x
x SuSE Linux 13.1-RELEASEx
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,
--external-tokens-path].
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>
Specifies required device type, for more info read BASIC ACTIONS
section in cryptsetup(8).
--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.
--volume-key-file, --master-key-file (OBSOLETE alias)
Use a volume key stored in a file. The volume key is stored in a
file instead of being printed out to standard output.
--dump-json-metadata
For luksDump (LUKS2 only) this option prints content of LUKS2
header JSON metadata area.
--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.
--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.
--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.
--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.
--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).
--unbound
Dumps existing LUKS2 unbound keyslot.
--external-tokens-path absolute_path
Override system directory path where cryptsetup searches for
external token handlers (or token plugins). It must be absolute
path (starting with '/' character).
--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.
--version, -V
Show the program version.
--usage
Show short option help.
--help, -?
Show help text and default parameters.
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/>.
cryptsetup 2.7.0 2024-08-30 CRYPTSETUP-LUKSDUMP(8)
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