gpgv(1) - f34

1GPGV(1)                      GNU Privacy Guard 2.2                     GPGV(1)
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NAME

6       gpgv - Verify OpenPGP signatures
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SYNOPSIS

9       gpgv [options] signed_files
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DESCRIPTION

14       gpgv is an OpenPGP signature verification tool.
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16       This  program  is actually a stripped-down version of gpg which is only
17       able to check signatures. It is somewhat smaller than  the  fully-blown
18       gpg  and  uses  a  different (and simpler) way to check that the public
19       keys used to make the signature are valid. There are  no  configuration
20       files and only a few options are implemented.
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22       gpgv  assumes  that all keys in the keyring are trustworthy.  That does
23       also mean that it does not check for expired or revoked keys.
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25       If no --keyring option is given, gpgv looks for a  ``default''  keyring
26       named  ‘trustedkeys.kbx’  (preferred)  or ‘trustedkeys.gpg’ in the home
27       directory of GnuPG, either the default home directory or the one set by
28       the  --homedir  option  or  the GNUPGHOME environment variable.  If any
29       --keyring option is used, gpgv will not look for the  default  keyring.
30       The  --keyring  option  may  be  used  multiple times and all specified
31       keyrings will be used together.
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RETURN VALUE

36       The program returns 0 if everything is fine, 1 if at least  one  signa‐
37       ture was bad, and other error codes for fatal errors.
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OPTIONS

41       gpgv recognizes these options:
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45       --verbose
46       -v     Gives more information during processing. If used twice, the in‐
47              put data is listed in detail.
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50       --quiet
51       -q     Try to be as quiet as possible.
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54       --keyring file
55              Add file to the list of keyrings.  If file begins with  a  tilde
56              and  a  slash,  these are replaced by the HOME directory. If the
57              filename does not contain a slash, it is assumed to  be  in  the
58              home-directory ("~/.gnupg" if --homedir is not used).
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61       --output file
62       -o file
63              Write output to file; to write to stdout use -.  This option can
64              be used to get the signed text from a cleartext or binary signa‐
65              ture;  it  also  works for detached signatures, but in that case
66              this option is in general not useful.   Note  that  an  existing
67              file will be overwritten.
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71       --status-fd n
72              Write  special status strings to the file descriptor n.  See the
73              file DETAILS in the documentation for a listing of them.
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76       --logger-fd n
77              Write log output to file descriptor n and not to stderr.
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80       --log-file file
81              Same as --logger-fd, except the logger data is written  to  file
82              file.  Use ‘socket://’ to log to socket.
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85       --ignore-time-conflict
86              GnuPG  normally  checks that the timestamps associated with keys
87              and signatures have plausible values. However, sometimes a  sig‐
88              nature  seems  to  be  older than the key due to clock problems.
89              This option turns these checks into warnings.
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92       --homedir dir
93              Set the name of the home directory to dir. If this option is not
94              used,  the  home  directory  defaults to ‘~/.gnupg’.  It is only
95              recognized when given on the command line.   It  also  overrides
96              any  home  directory  stated  through  the  environment variable
97              ‘GNUPGHOME’ or (on Windows systems) by means of the Registry en‐
98              try HKCU\Software\GNU\GnuPG:HomeDir.
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100              On Windows systems it is possible to install GnuPG as a portable
101              application.  In this case only this command line option is con‐
102              sidered, all other ways to set a home directory are ignored.
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104              To install GnuPG as a portable application under Windows, create
105              an empty file named ‘gpgconf.ctl’ in the same directory  as  the
106              tool  ‘gpgconf.exe’.   The root of the installation is then that
107              directory; or, if ‘gpgconf.exe’ has been installed directly  be‐
108              low  a  directory  named  ‘bin’, its parent directory.  You also
109              need to make sure that the following directories exist  and  are
110              writable:     ‘ROOT/home’     for    the    GnuPG    home    and
111              ‘ROOT/var/cache/gnupg’ for internal cache files.
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114       --weak-digest name
115              Treat the specified digest algorithm as weak.   Signatures  made
116              over  weak digests algorithms are normally rejected. This option
117              can be supplied multiple times if multiple algorithms should  be
118              considered  weak.   MD5  is always considered weak, and does not
119              need to be listed explicitly.
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122       --enable-special-filenames
123              This option enables a mode in which filenames of the form ‘-&n’,
124              where  n is a non-negative decimal number, refer to the file de‐
125              scriptor n and not to a file with that name.
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EXAMPLES

129       gpgv pgpfile
130       gpgv sigfile [datafile]
131              Verify the signature of the file. The second form  is  used  for
132              detached  signatures,  where  sigfile  is the detached signature
133              (either ASCII-armored  or  binary)  and  datafile  contains  the
134              signed  data;  if datafile is "-" the signed data is expected on
135              stdin; if datafile is not given the name of the file holding the
136              signed data is constructed by cutting off the extension (".asc",
137              ".sig" or ".sign") from sigfile.
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FILES

141       ~/.gnupg/trustedkeys.gpg
142              The default keyring with the allowed keys.
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ENVIRONMENT

146       HOME   Used to locate the default home directory.
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149       GNUPGHOME
150              If set directory used instead of "~/.gnupg".
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