tarsnap-keymgmt man page

tarsnap-keymgmt — generate subsets of tarsnap(1) key files


tarsnap-keymgmt --outkeyfile new-key-file [-r] [-w] [-d] [--nuke] [--passphrased] [--passphrase-mem maxmem] [--passphrase-time maxtime] key-file ...

tarsnap-keymgmt --print-key-id key-file

tarsnap-keymgmt --print-key-permissions key-file

tarsnap-keymgmt --version


tarsnap-keymgmt reads the provided key files and writes a new key file (specified by --outkeyfile new-key-file) containing only the keys required for the operations specified via the -r (list and extract archives), -w (write archives), -d (delete archives), and --nuke flags. Note that -d implies -r since it is impossible to delete an individual archive without being able to read it; while a key file generated with --nuke can be used to delete all the archives stored, but not individual archives.

The following list shows which permissions are required for various tarsnap(1) command modes.


requires either (1) -d (archive deleting), (2) -w (archive creating), or (3) --nuke keys.


requires either (1) both -w (archive writing) and -r (archive reading) keys, or (2) -d (archive deleting) keys.


requires -d (archive deleting) keys, since it needs to be able to delete corrupted archives.

If the --passphrased option is specified, the user will be prompted to enter a passphrase (twice) to be used to encrypt the key file.

If the --passphrase-mem maxmem option is specified, a maximum of maxmem bytes of RAM will be used in the scrypt key derivation function to encrypt the key file; it may be necessary to set this option if a key file is being created on a system with far more RAM than the system on which the key file will be used.

If the --passphrase-time maxtime option is specified, a maximum of approximately maxtime seconds will be used in the scrypt key derivation function to encrypt the key file.

Note that if none of the -w, -r, -d, or --nuke options are specified, a key file will be produced which does not contain any keys. This is probably not very useful.

The --print-key-id key-file option displays the 64-bit integer corresponding to the key's machine number. This may be useful for scripts or GUIs which manage a user's Tarsnap account, but is not likely to be helpful for command-line use.

The --print-key-permissions key-file option displays the permissions which the key possesses.

The --version option prints the version number of tarsnap-keymgmt, then exits.