gpgv - Verify OpenPGP signatures
gpgv [
options]
signed_files
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.
If no
--keyring option is given,
gpgv looks for a ``default''
keyring named ‘
trustedkeys.kbx’ (preferred) or ‘
trustedkeys.gpg’ in the home directory of GnuPG, either the
default home directory or the one set by the
--homedir option or the
GNUPGHOME environment variable. If any
--keyring option is used,
gpgv will not look for the default keyring. The
--keyring option
may be used multiple times and all specified keyrings will be used together.
The program returns 0 if everything is fine, 1 if at least one signature was
bad, and other error codes for fatal errors.
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.
- 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.
- ~/.gnupg/trustedkeys.gpg
- The default keyring with the allowed keys.
- HOME
- Used to locate the default home directory.
- GNUPGHOME
- If set directory used instead of "~/.gnupg".
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
should give you access to the complete manual including a menu structure and an
index.