Tribblix: manual page: gpgv2.1

GPGV2(1) GNU Privacy Guard 2.2 GPGV2(1)

NAME

gpgv2 - Verify OpenPGP signatures

SYNOPSIS

gpgv2 [options] signed_files

DESCRIPTION

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 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.

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

gpgv2 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/usr/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

gpgv2 pgpfile
gpgv2 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".