bionic (1) gpgv2.1.gz

NAME

       gpgv - Verify OpenPGP signatures

SYNOPSIS

       gpgv [options] signed_files

DESCRIPTION

       gpgv is an OpenPGP signature verification tool.

       This  program  is  actually  a stripped-down version of gpg which is only able to check signatures. It is
       somewhat smaller than the fully-blown gpg and uses a different (and simpler) way to check that the public
       keys  used  to  make the signature are valid. There are no configuration files and only a few options are
       implemented.

       gpgv assumes that all keys in the keyring are trustworthy.  That does also mean that it  does  not  check
       for expired or revoked keys.

       By  default  a  keyring  named  ‘trustedkeys.kbx’  is  used;  if  that  does  not  exist  a keyring named
       ‘trustedkeys.gpg’ is used.  The default keyring is assumed to be in the home directory of  GnuPG,  either
       the  default home directory or the one set by an option or an environment variable.  The option --keyring
       may be used to specify a different keyring or even multiple keyrings.

RETURN VALUE

       The program returns 0 if everything is fine, 1 if at least one signature was bad, and other  error  codes
       for fatal errors.

OPTIONS

       gpgv recognizes these options:

       --verbose
       -v     Gives more information during processing. If used twice, the input data is listed in detail.

       --quiet
       -q     Try to be as quiet as possible.

       --keyring file
              Add  file to the list of keyrings.  If file begins with a tilde and a slash, these are replaced by
              the HOME directory. If the filename does not contain a slash, it is assumed to  be  in  the  home-
              directory ("~/.gnupg" if --homedir is not used).

       --output file
       -o file
              Write  output  to  file; to write to stdout use -.  This option can be used to get the signed text
              from a cleartext or binary signature; it also works for detached signatures, but in that case this
              option is in general not useful.  Note that an existing file will be overwritten.

       --status-fd n
              Write  special status strings to the file descriptor n.  See the file DETAILS in the documentation
              for a listing of them.

       --logger-fd n
              Write log output to file descriptor n and not to stderr.

       --log-file file
              Same as --logger-fd, except the logger data is written to file file.  Use ‘socket://’  to  log  to
              socket.

       --ignore-time-conflict
              GnuPG  normally  checks  that  the  timestamps  associated with keys and signatures have plausible
              values. However, sometimes a signature seems to be older than the key due to clock problems.  This
              option turns these checks into warnings.

       --homedir dir
              Set the name of the home directory to dir. If this option is not used, the home directory defaults
              to ‘~/.gnupg’.  It is only recognized when given on the command line.  It also overrides any  home
              directory  stated through the environment variable ‘GNUPGHOME’ or (on Windows systems) by means of
              the Registry entry HKCU\Software\GNU\GnuPG:HomeDir.

              On Windows systems it is possible to install GnuPG as a portable application.  In this  case  only
              this command line option is considered, all other ways to set a home directory are ignored.

              To install GnuPG as a portable application under Windows, create an empty file named ‘gpgconf.ctl’
              in the same directory as the tool ‘gpgconf.exe’.  The  root  of  the  installation  is  then  that
              directory;  or,  if  ‘gpgconf.exe’  has been installed directly below a directory named ‘bin’, its
              parent directory.  You also need to make  sure  that  the  following  directories  exist  and  are
              writable: ‘ROOT/home’ for the GnuPG home and ‘ROOT/var/cache/gnupg’ for internal cache files.

       --weak-digest name
              Treat  the  specified  digest algorithm as weak.  Signatures made over weak digests algorithms are
              normally rejected. This option can be supplied multiple times if  multiple  algorithms  should  be
              considered weak.  MD5 is always considered weak, and does not need to be listed explicitly.

       --enable-special-filenames
              This option enables a mode in which filenames of the form ‘-&n’, where n is a non-negative decimal
              number, refer to the file descriptor n and not to a file with that name.

EXAMPLES

       gpgv pgpfile
       gpgv sigfile [datafile]
              Verify the signature of the file. The second form is used for detached signatures,  where  sigfile
              is  the detached signature (either ASCII-armored or binary) and datafile contains the signed data;
              if datafile is "-" the signed data is expected on stdin; if datafile is not given the name of  the
              file  holding  the  signed  data  is  constructed  by cutting off the extension (".asc", ".sig" or
              ".sign") from sigfile.

FILES

       ~/.gnupg/trustedkeys.gpg
              The default keyring with the allowed keys.

ENVIRONMENT

       HOME   Used to locate the default home directory.

       GNUPGHOME
              If set directory used instead of "~/.gnupg".

SEE ALSO

       gpg(1)

       The full documentation for this tool is maintained as a Texinfo manual.  If GnuPG and  the  info  program
       are properly installed at your site, the command

         info gnupg

       should give you access to the complete manual including a menu structure and an index.