7.2 Verify OpenPGP signatures

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. By default it uses a keyring named trustedkeys.gpg which is assumed to be in the home directory as defined by GnuPG or set by an option or an environment variable. An option may be used to specify another keyring or even multiple keyrings.

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).

--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.

--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 W32 systems) by means of the Registry entry HKCU\Software\GNU\GnuPG:HomeDir.

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

7.2.1 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.

7.2.2 Environment

HOME

Used to locate the default home directory.

GNUPGHOME

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

7.2.3 FILES

~/.gnupg/trustedkeys.gpg

The default keyring with the allowed keys.

gpg2(1)