# cryptsetup-luksDump

## 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. With the
           --volume-key-file option, the 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.
    
           A passphrase must be supplied to dump the volume key, either
           interactively or via --key-file.
    
           To dump an unbound key (LUKS2 format only), --unbound parameter,
           specific --key-slot id and proper passphrase must be supplied,
           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 the --dump-json-metadata option.
    
           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> **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].
    


## 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 is 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).
    
           **--dump-json-metadata**
               For _luksDump_ (LUKS2 only), this option prints the content of
               the 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.
    
           **--external-tokens-path** _< absolute path>_
               Override the system directory path where cryptsetup searches
               for external token handlers (or token plugins). It must be an
               absolute path (starting with '/' character).
    
           **--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 the
               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-description** _text_
               Set the key description in the keyring that will be used for
               passphrase retrieval.
    
           **--key-file** , **-d** _file_
               Read the passphrase from the 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 keyslot is selected for the new key.
    
               The maximum number of keyslots depends on the LUKS version.
               LUKS1 can have up to 8 keyslots. LUKS2 can have up to 32
               keyslots based on keyslot area size and key size, but a valid
               keyslot ID can always be between 0 and 31 for LUKS2.
    
           **--timeout** , **-t** _seconds_
               The number of seconds to wait before a 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.
    
           **--type** _type_
               Specifies required device type, for more info, read the _BASIC_
               _ACTIONS_ section in cryptsetup(8).
    
           **--unbound**
               Dumps the existing LUKS2 unbound keyslot.
    
           **--usage**
               Show short option help.
    
           **--version** , **-V**
               Show the program version.
    
           **--volume-key-file** _file_ , --master-key-file 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.
    


## CRYPTSETUP



           Part of cryptsetup project
           <https://gitlab.com/cryptsetup/cryptsetup/>. This page is part of
           the _Cryptsetup_ ((open-source disk encryption)) project.
           Information about the project can be found at 
           ⟨https://gitlab.com/cryptsetup/cryptsetup⟩. If you have a bug
           report for this manual page, send it to dm-crypt@saout.de. This
           page was obtained from the project's upstream Git repository
           ⟨https://gitlab.com/cryptsetup/cryptsetup.git⟩ on 2025-08-11. (At
           that time, the date of the most recent commit that was found in
           the repository was 2025-08-01.) If you discover any rendering
           problems in this HTML version of the page, or you believe there is
           a better or more up-to-date source for the page, or you have
           corrections or improvements to the information in this COLOPHON
           (which is _not_ part of the original manual page), send a mail to
           man-pages@man7.org
    
    cryptsetup 2.8.1-git            2025-08-09         _CRYPTSETUP-LUKSDUMP_(8)
    


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