gpgv2 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.
gpgv2 assumes that all keys in the keyring are trustworthy.
That does also mean that it does not check for expired or revoked
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.
gpgv2 recognizes these options:
Gives more information during processing. If used twice, the input data is listed in detail.
Try to be as quiet as possible.
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).
Write special status strings to the file descriptor n. See the file DETAILS in the documentation for a listing of them.
Write log output to file descriptor
n and not to stderr.
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.
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
(on Windows systems) by means of the Registry entry
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 name gpgconf.ctl in the same directory as the tool gpgconf.exe. The root of the installation is than 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/usr/local/var/cache/gnupg for internal cache files.
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.
The program returns 0 if everything is fine, 1 if at least one signature was bad, and other error codes for fatal errors.
Verify the signature of the file. The second form is used for detached
sigfile is the detached signature (either
ASCII-armored or binary) and
datafile contains the signed data;
datafile is "-" the signed data is expected on
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
Used to locate the default home directory.
If set directory used instead of "~/.gnupg".
The default keyring with the allowed keys.