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<H1>GPGV</H1>
Section: GNU Privacy Guard 2.2 (1)<BR>Updated: 2019-11-23<BR><A HREF="#index">Index</A>
<A HREF="/cgi-bin/man/man2html">Return to Main Contents</A><HR>
<A NAME="lbAB">&nbsp;</A>
<H2>NAME</H2>
<B>gpgv</B>
- Verify OpenPGP signatures
<A NAME="lbAC">&nbsp;</A>
<H2>SYNOPSIS</H2>
<B>gpgv</B>
[<I>options</I>]
<I>signed_files</I>
<P>
<P>
<A NAME="lbAD">&nbsp;</A>
<H2>DESCRIPTION</H2>
<B>gpgv</B> is an OpenPGP signature verification tool.
<P>
This program is actually a stripped-down version of <B>gpg</B> which is
only able to check signatures. It is somewhat smaller than the fully-blown
<B>gpg</B> 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.
<P>
<B>gpgv</B> assumes that all keys in the keyring are trustworthy.
That does also mean that it does not check for expired or revoked
keys.
<P>
If no <B>--keyring</B> option is given, <B>gpgv</B> looks for a
``default'' keyring named '<I>trustedkeys.kbx</I>' (preferred) or
'<I>trustedkeys.gpg</I>' in the home directory of GnuPG, either the
default home directory or the one set by the <B>--homedir</B> option
or the <B>GNUPGHOME</B> environment variable. If any <B>--keyring</B>
option is used, <B>gpgv</B> will not look for the default keyring. The
<B>--keyring</B> option may be used multiple times and all specified
keyrings will be used together.
<P>
<P>
<A NAME="lbAE">&nbsp;</A>
<H2>RETURN VALUE</H2>
<P>
The program returns 0 if everything is fine, 1 if at least
one signature was bad, and other error codes for fatal errors.
<P>
<A NAME="lbAF">&nbsp;</A>
<H2>OPTIONS</H2>
<B>gpgv</B> recognizes these options:
<P>
<P>
<DL COMPACT>
<DT id="1"><B>--verbose</B>
<DD>
<B>-v</B>
Gives more information during processing. If used
twice, the input data is listed in detail.
<P>
<DT id="2"><B>--quiet</B>
<DD>
<B>-q</B>
Try to be as quiet as possible.
<P>
<DT id="3"><B>--keyring </B><I>file</I>
<DD>
Add <I>file</I> to the list of keyrings.
If <I>file</I> 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 (&quot;~/.gnupg&quot; if --homedir is not used).
<P>
<DT id="4"><B>--output </B><I>file</I>
<DD>
<B>-o </B><I>file</I>
Write output to <I>file</I>; to write to stdout use <B>-</B>. 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.
<P>
<P>
<DT id="5"><B>--status-fd </B><I>n</I>
<DD>
Write special status strings to the file descriptor <I>n</I>. See the
file DETAILS in the documentation for a listing of them.
<P>
<DT id="6"><B>--logger-fd n</B>
<DD>
Write log output to file descriptor <B>n</B> and not to stderr.
<P>
<DT id="7"><B>--log-file file</B>
<DD>
Same as <B>--logger-fd</B>, except the logger data is written to
file <B>file</B>. Use '<I>socket://</I>' to log to socket.
<P>
<DT id="8"><B>--ignore-time-conflict</B>
<DD>
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.
<P>
<DT id="9"><B>--homedir </B><I>dir</I>
<DD>
Set the name of the home directory to <I>dir</I>. If this option is not
used, the home directory defaults to '<I>~/.gnupg</I>'. It is only
recognized when given on the command line. It also overrides any home
directory stated through the environment variable '<I>GNUPGHOME</I>' or
(on Windows systems) by means of the Registry entry
<I>HKCU\Software\GNU\GnuPG:HomeDir</I>.
<P>
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.
<P>
To install GnuPG as a portable application under Windows, create an
empty file named '<I>gpgconf.ctl</I>' in the same directory as the tool
'<I>gpgconf.exe</I>'. The root of the installation is then that
directory; or, if '<I>gpgconf.exe</I>' has been installed directly below
a directory named '<I>bin</I>', its parent directory. You also need to
make sure that the following directories exist and are writable:
'<I>ROOT/home</I>' for the GnuPG home and '<I>ROOT/var/cache/gnupg</I>'
for internal cache files.
<P>
<DT id="10"><B>--weak-digest name</B>
<DD>
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.
<P>
<DT id="11"><B>--enable-special-filenames</B>
<DD>
This option enables a mode in which filenames of the form
'<I>-&amp;n</I>', where n is a non-negative decimal number,
refer to the file descriptor n and not to a file with that name.
<P>
</DL>
<P>
<P>
<A NAME="lbAG">&nbsp;</A>
<H2>EXAMPLES</H2>
<P>
<P>
<DL COMPACT>
<DT id="12"><B>gpgv pgpfile</B>
<DD>
<B>gpgv sigfile</B> [<B>datafile</B>]
Verify the signature of the file. The second form is used for detached
signatures, where <B>sigfile</B> is the detached signature (either
ASCII-armored or binary) and <B>datafile</B> contains the signed data;
if <B>datafile</B> is &quot;-&quot; the signed data is expected on
<B>stdin</B>; if <B>datafile</B> is not given the name of the file
holding the signed data is constructed by cutting off the extension
(&quot;.asc&quot;, &quot;.sig&quot; or &quot;.sign&quot;) from <B>sigfile</B>.
<P>
</DL>
<P>
<P>
<A NAME="lbAH">&nbsp;</A>
<H2>FILES</H2>
<P>
<P>
<DL COMPACT>
<DT id="13"><B>~/.gnupg/trustedkeys.gpg</B>
<DD>
The default keyring with the allowed keys.
<P>
</DL>
<P>
<P>
<A NAME="lbAI">&nbsp;</A>
<H2>ENVIRONMENT</H2>
<P>
<P>
<DL COMPACT>
<DT id="14"><B>HOME</B>
<DD>
Used to locate the default home directory.
<P>
<DT id="15"><B>GNUPGHOME</B>
<DD>
If set directory used instead of &quot;~/.gnupg&quot;.
<P>
</DL>
<P>
<P>
<A NAME="lbAJ">&nbsp;</A>
<H2>SEE ALSO</H2>
<B><A HREF="/cgi-bin/man/man2html?1+gpg">gpg</A></B>(1)
<P>
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
<P>
<DL COMPACT><DT id="16"><DD>
<PRE>
info gnupg
</PRE>
</DL>
<P>
should give you access to the complete manual including a menu structure
and an index.
<P>
<P>
<P>
<P>
<P>
<HR>
<A NAME="index">&nbsp;</A><H2>Index</H2>
<DL>
<DT id="17"><A HREF="#lbAB">NAME</A><DD>
<DT id="18"><A HREF="#lbAC">SYNOPSIS</A><DD>
<DT id="19"><A HREF="#lbAD">DESCRIPTION</A><DD>
<DT id="20"><A HREF="#lbAE">RETURN VALUE</A><DD>
<DT id="21"><A HREF="#lbAF">OPTIONS</A><DD>
<DT id="22"><A HREF="#lbAG">EXAMPLES</A><DD>
<DT id="23"><A HREF="#lbAH">FILES</A><DD>
<DT id="24"><A HREF="#lbAI">ENVIRONMENT</A><DD>
<DT id="25"><A HREF="#lbAJ">SEE ALSO</A><DD>
</DL>
<HR>
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