NAME

       gfsec-use - Make use of a shared secret

SYNOPSIS

       gfsec-use [-h|--help] [-v|--version] [-c|--config file] [-k|--keep] [-o|--output file]
                 [-r|--restore-cmd command] [-d|--destroy-cmd command] [command...]

DESCRIPTION

       gfsec-use reconstructs a secret file that has been previously  split  using  a  tool  like
       gfsplit(1) or the accompanying program gfsec-split(1).

       A user-specified command (or a shell) is spawn once the secret has been reconstructed, and
       the secret file is deleted when the command terminates.

OPTIONS

       -h, --help
              Display the help message.

       -v, --version
              Display the version message.

       -c, --config file
              Specify a configuration file. If  the  specified  file  does  not  exist,  a  .conf
              extension  is  appended  to  the  filename  and a corresponding file is searched in
              $XDG_CONFIG_HOME/gfsecret. When that option is not used,  a  default  configuration
              $XDG_CONFIG_HOME/gfsecret/default.conf is assumed.

       -k, --keep
              Do not delete the reconstructed file upon termination of the specified command.

       -o, --output file
              Write  the  reconstructed  secret in the specified file. This overrides the OUTFILE
              parameter in the configuration file.

       -r, --restore-cmd command
              Execute the specified command instead of writing  the  reconstructed  secret  to  a
              file. The secret is sent to the command's standard input.

       -d, --destroy-cmd command
              Execute  the  specified  command  instead of deleting the reconstructed secret file
              upon termination.

CONFIGURATION FILE

       A configuration file describes one secret file to  reconstruct.   Blank  lines  and  lines
       starting with a # character are ignored.

       The following directives can be used:

       OUTFILE=file
              Specify the file to write the reconstructed secret into.

       RESTORE=command
              Specify the command to execute once the secret has been reconstructed.

       DESTROY=command
              Specify the command to execute to destroy the secret upon termination.

       MINSHARES=n
              Specify  the minimal number of shares needed to reconstruct the secret. The default
              if unspecified is 2.

       URI=uri
              Specify an URI indicating where to find a share.

       Supported URI schemes are:

       file:///
              Indicates a file on the local filesystem.

       uuid://uuid/
              Indicates a file on the external volume identified by the specified UUID.

       label://label/
              Indicates a file on the external volume identified by the specified label.

       mtp://serial/
              Indicates a file on the MTP device identified by the specified serial number.

       http://host/
              Indicates a file on a web server identified by its hostname.

       https://host/
              Same as the previous one, but the web server is to be  accessed  through  a  secure
              connection.

       Whatever  the  scheme,  the file part of the URI must end with an extension indicating the
       share number, as generated by gfsplit(1).

       The URI may include a share=no parameter, indicating that the corresponding file  contains
       the  whole  secret and not only a share (in that case, the previous remark about the share
       number in the extension does not apply).

       Another parameter is sha256, which specifies the expected SHA-256 hash value of the  share
       data.  If such a parameter is specified, a share will only be used if the data matches the
       expected hash value.

       The gfsec-split(1) program, used to split a file into shares, will automatically  generate
       a suitable configuration file allowing to reconstruct the original file.

EXAMPLE CONFIGURATION FILE

       OUTFILE=/home/alice/mysecret
       MINSHARES=2
       URI=file:///home/alice/.local/share/gfsecret/mysecret.024
       URI=label://USBSTICK/mysecret.070?sha256=hex_hash
       URI=mtp://RF2GB6X704P/Documents/mysecret.139

REPORTING BUGS

       Report bugs to Damien Goutte-Gattat ⟨devel@incenp.org⟩.

SEE ALSO

       gfsec-split(1), gfsplit(1), gfcombine(1), libgfshare(3), gfshare(7)

COPYRIGHT

       Copyright © 2017,2021 Damien Goutte-Gattat

       This program is released under the GNU General Public License.  See the COPYING file in
       the source distribution or ⟨http://www.gnu.org/licenses/gpl.html⟩.