CRYPTSETUP-TCRYPTDUMP(8) Maintenance Commands CRYPTSETUP-TCRYPTDUMP(8)

cryptsetup-tcryptDump - dump the header information of a TCRYPT (TrueCrypt or VeraCrypt compatible) device

cryptsetup tcryptDump [<options>] <device>

Dump the header information of a TCRYPT (TrueCrypt or VeraCrypt compatible) device.

If the --dump-volume-key option is used, the TCRYPT device volume key is dumped instead of TCRYPT header info. Beware that the volume key (or concatenated volume keys if cipher chain is used) can be used to decrypt the data stored in the TCRYPT container without a passphrase. This means that if the volume key is compromised, the whole device has to be erased to prevent further access. Use this option carefully.

<options> can be [--dump-volume-key, --key-file, --tcrypt-hidden, --tcrypt-system, --tcrypt-backup, --veracrypt (ignored), --disable-veracrypt, --veracrypt-pim, --veracrypt-query-pim, --cipher, --hash, --header, --verify-passphrase, --timeout].

The keyfile parameter allows a combination of file content with the passphrase and can be repeated.

--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.

--cipher, -c <cipher-spec>

Set the cipher specification string for plain device type.

For tcrypt device type it restricts checked cipher chains when looking for header.

--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-veracrypt

This option can be used to disable VeraCrypt compatible mode (only TrueCrypt devices are recognized). Only for TCRYPT extension. See TCRYPT section in cryptsetup(8) for more info.

--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.

--hash, -h <hash-spec>

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.

--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.

--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.

--tcrypt-backup, --tcrypt-hidden, --tcrypt-system

Specify which TrueCrypt on-disk header will be used to open the device. See TCRYPT section in cryptsetup(8) for more info.

--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.

--veracrypt

This option is ignored as VeraCrypt compatible mode is supported by default.

--veracrypt-pim, --veracrypt-query-pim

Use a custom Personal Iteration Multiplier (PIM) for VeraCrypt device. See TCRYPT section in cryptsetup(8) for more info.

--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.

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.

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

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

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

2023-07-18 cryptsetup 2.7.2