gpg-agent

       gpg-agent [--homedir dir] [--options file] [options]
       gpg-agent [--homedir dir] [--options file] [options] --server
       gpg-agent  [--homedir  dir]  [--options  file] [options] --daemon [com-
       mand_line]

DESCRIPTION
       gpg-agent is a daemon to manage  secret  (private)  keys  independently
       from  any  protocol.  It is used as a backend for gpg and gpgsm as well
       as for a couple of other utilities.

       The agent is automatically started on demand by gpg, gpgsm, gpgconf, or
       gpg-connect-agent.   Thus  there is no reason to start it manually.  In
       case you want to use the included Secure Shell Agent you may start  the
       agent using:

         gpg-connect-agent /bye

       You  should  always add the following lines to your .bashrc or whatever
       initialization file is used for all shell invocations:

         GPG_TTY=$(tty)
         export GPG_TTY

       It is important that this environment variable always reflects the out-
       put of the tty command.  For W32 systems this option is not required.

       Please  make  sure  that  a  proper pinentry program has been installed
       under the default filename (which  is  system  dependent)  or  use  the
       option  pinentry-program  to specify the full name of that program.  It
       is often useful to install a symbolic link from the actual used  pinen-
       try   (e.g.   '/usr/bin/pinentry-gtk')   to   the  expected  one  (e.g.
       '/usr/bin/pinentry').

COMMANDS
       Commands are not distinguished from options except for  the  fact  that
       only one command is allowed.

       --version
              Print  the program version and licensing information.  Note that
              you cannot abbreviate this command.

       --help

       -h     Print a usage message summarizing the most  useful  command-line
              options.  Note that you cannot abbreviate this command.

       --dump-options
              Print  a  list of all available options and commands.  Note that
              you cannot abbreviate this command.

       --server
              Run in server mode and wait for  commands  on  the  stdin.   The
              default  mode  is  to  create  a  socket and listen for commands
              there.
              Reads configuration from file instead of from the  default  per-
              user  configuration  file.   The  default  configuration file is
              named 'gpg-agent.conf' and expected in  the  '.gnupg'  directory
              directly below the home directory of the user.

       --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 con-
              sidered, 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/var/cache/gnupg2' for internal cache files.

       -v

       --verbose
              Outputs  additional information while running.  You can increase
              the verbosity by giving several verbose commands to gpgsm,  such
              as '-vv'.

       -q

       --quiet
              Try to be as quiet as possible.

       --batch
              Don't  invoke  a  pinentry or do any other thing requiring human
              interaction.

       --faked-system-time epoch
              This option is only useful for testing; it sets the system  time
              back  or  forth  to epoch which is the number of seconds elapsed
              since the year 1970.

       --debug-level level
              Select the debug level for investigating problems. level may  be
              a numeric value or a keyword:

              none   No  debugging at all.  A value of less than 1 may be used
                     instead of the keyword.

                     of  hash  tracing files is only enabled if the keyword is
                     used.

       How these messages are mapped to the  actual  debugging  flags  is  not
       specified  and may change with newer releases of this program. They are
       however carefully selected to best aid in debugging.

       --debug flags
              This option is only useful for debugging and the  behaviour  may
              change  at  any  time without notice.  FLAGS are bit encoded and
              may be given in usual C-Syntax. The currently defined bits are:

              0 (1)  X.509 or OpenPGP protocol related data

              1 (2)  values of big number integers

              2 (4)  low level crypto operations

              5 (32) memory allocation

              6 (64) caching

              7 (128)
                     show memory statistics.

              9 (512)
                     write hashed data to files named dbgmd-000*

              10 (1024)
                     trace Assuan protocol

              12 (4096)
                     bypass all certificate validation

       --debug-all
              Same as --debug=0xffffffff

       --debug-wait n
              When running in server mode, wait n seconds before entering  the
              actual  processing  loop  and print the pid.  This gives time to
              attach a debugger.

       --debug-quick-random
              This option inhibits the use of the very secure  random  quality
              level  (Libgcrypt's  GCRY_VERY_STRONG_RANDOM)  and  degrades all
              request down to standard random quality.  It is  only  used  for
              testing  and  shall not be used for any production quality keys.
              This option is only effective when given on the command line.

       --debug-pinentry
              This option enables extra debug information  pertaining  to  the
              Pinentry.   As  of  now  it  is only useful when used along with
              --debug 1024.

              guess  it  based on the environment variable SHELL which is cor-
              rect in almost all cases.

       --no-grab
              Tell the pinentry not to grab  the  keyboard  and  mouse.   This
              option  should  in  general  not  be  used  to  avoid X-sniffing
              attacks.

       --log-file file
              Append all logging output to file.  This is very helpful in see-
              ing  what  the agent actually does.  If neither a log file nor a
              log file descriptor has been set on a Windows platform, the Reg-
              istry  entry  HKCU\Software\GNU\GnuPG:DefaultLogFile, if set, is
              used to specify the logging output.

       --no-allow-mark-trusted
              Do not allow clients to mark keys as trusted, i.e. put them into
              the  'trustlist.txt'  file.   This  makes it harder for users to
              inadvertently accept Root-CA keys.

       --allow-preset-passphrase
              This option allows the use of gpg-preset-passphrase to seed  the
              internal cache of gpg-agent with passphrases.

       --allow-loopback-pinentry
              Allow  clients  to  use  the loopback pinentry features; see the
              option pinentry-mode for details.

       --no-allow-external-cache
              Tell Pinentry not to enable features which use an external cache
              for passphrases.

              Some  desktop environments prefer to unlock all credentials with
              one master password and may  have  installed  a  Pinentry  which
              employs an additional external cache to implement such a policy.
              By using this option the Pinentry is advised not to make use  of
              such  a  cache and instead always ask the user for the requested
              passphrase.

       --allow-emacs-pinentry
              Tell Pinentry to allow features to divert the  passphrase  entry
              to  a  running  Emacs  instance.   How  this  is exactly handled
              depends on the version of the used Pinentry.

       --ignore-cache-for-signing
              This option will let gpg-agent bypass the passphrase  cache  for
              all  signing  operation.   Note that there is also a per-session
              option to control this behaviour but this  command  line  option
              takes precedence.

       --default-cache-ttl n
              Set  the  time a cache entry is valid to n seconds.  The default
              is 600 seconds.  Each  time  a  cache  entry  is  accessed,  the
              entry's timer is reset.  To set an entry's maximum lifetime, use
              The default is 2 hours (7200 seconds).

       --max-cache-ttl-ssh n
              Set the maximum time a cache entry used for SSH keys is valid to
              n  seconds.   After this time a cache entry will be expired even
              if it has been accessed recently or has been set using  gpg-pre-
              set-passphrase.  The default is 2 hours (7200 seconds).

       --enforce-passphrase-constraints
              Enforce  the  passphrase constraints by not allowing the user to
              bypass them using the ``Take it anyway'' button.

       --min-passphrase-len n
              Set the minimal length of a passphrase.   When  entering  a  new
              passphrase  shorter than this value a warning will be displayed.
              Defaults to 8.

       --min-passphrase-nonalpha n
              Set the minimal number of digits or special characters  required
              in  a passphrase.  When entering a new passphrase with less than
              this number of digits or special characters a  warning  will  be
              displayed.  Defaults to 1.

       --check-passphrase-pattern file
              Check  the  passphrase  against the pattern given in file.  When
              entering a new passphrase matching one of these pattern a  warn-
              ing will be displayed. file should be an absolute filename.  The
              default is not to use any pattern file.

              Security note: It is known that checking a passphrase against  a
              list  of  pattern  or  even against a complete dictionary is not
              very effective to enforce good  passphrases.   Users  will  soon
              figure  up  ways to bypass such a policy.  A better policy is to
              educate users on good security behavior and optionally to run  a
              passphrase  cracker  regularly on all users passphrases to catch
              the very simple ones.

       --max-passphrase-days n
              Ask the user to change the passphrase  if  n  days  have  passed
              since  the  last  change.  With --enforce-passphrase-constraints
              set the user may not bypass this check.

       --enable-passphrase-history
              This option does nothing yet.

       --pinentry-invisible-char char
              This option asks the Pinentry to use char for displaying  hidden
              characters.   char must be one character UTF-8 string.  A Pinen-
              try may or may not honor this request.

       --pinentry-timeout n
              This option asks the Pinentry to timeout after n seconds with no
              user input.  The default value of 0 does not ask the pinentry to
              timeout, however a Pinentry may  use  its  own  default  timeout
              '..\GNU\GnuPG\pinentry.exe',          '..\GNU\bin\pinentry.exe',
              'bin\pinentry-basic.exe'  where  the  file names are relative to
              the GnuPG installation directory.

       --pinentry-touch-file filename
              By default the filename of the socket gpg-agent is listening for
              requests  is  passed to Pinentry, so that it can touch that file
              before exiting (it does this only in curses mode).  This  option
              changes  the  file  passed to Pinentry to filename.  The special
              name /dev/null may be used to completely disable  this  feature.
              Note  that  Pinentry  will  not  create  that file, it will only
              change the modification and access time.

       --scdaemon-program filename
              Use program filename as the Smartcard daemon.   The  default  is
              installation  dependent  and  can be shown with the gpgconf com-
              mand.

       --disable-scdaemon
              Do not make use of the  scdaemon  tool.   This  option  has  the
              effect  of  disabling  the  ability  to do smartcard operations.
              Note, that enabling this option at  runtime  does  not  kill  an
              already forked scdaemon.

       --disable-check-own-socket
              gpg-agent  employs  a  periodic  self-test  to  detect  a stolen
              socket.  This usually means a second instance of  gpg-agent  has
              taken  over the socket and gpg-agent will then terminate itself.
              This option may be used to disable this self-test for  debugging
              purposes.

       --use-standard-socket

       --no-use-standard-socket

       --use-standard-socket-p
              Since  GnuPG  2.1  the  standard  socket  is always used.  These
              options have no more effect.  The command gpg-agent  --use-stan-
              dard-socket-p will thus always return success.

       --display string

       --ttyname string

       --ttytype string

       --lc-ctype string

       --lc-messages string

       --xauthority string
              These options are used with the server mode to pass localization
              information.

              connect to the local gpg-agent and use its private  keys.   This
              allows  to  decrypt  or  sign  data  on a remote machine without
              exposing the private keys to the remote machine.

       --enable-ssh-support

       --enable-putty-support

              Enable the OpenSSH Agent protocol.

              In this mode of operation, the agent does not only implement the
              gpg-agent  protocol, but also the agent protocol used by OpenSSH
              (through a separate socket).  Consequently, it should be  possi-
              ble  to  use the gpg-agent as a drop-in replacement for the well
              known ssh-agent.

              SSH Keys, which are to be used through the  agent,  need  to  be
              added  to  the  gpg-agent initially through the ssh-add utility.
              When a key is added, ssh-add will ask for the  password  of  the
              provided  key  file and send the unprotected key material to the
              agent; this causes the gpg-agent to ask for a passphrase,  which
              is  to be used for encrypting the newly received key and storing
              it in a gpg-agent specific directory.

              Once a key has been added to the gpg-agent this  way,  the  gpg-
              agent will be ready to use the key.

              Note:  in  case  the gpg-agent receives a signature request, the
              user might need to be prompted for a passphrase, which is neces-
              sary  for decrypting the stored key.  Since the ssh-agent proto-
              col does not contain a mechanism for telling the agent on  which
              display/terminal it is running, gpg-agent's ssh-support will use
              the TTY or X display  where  gpg-agent  has  been  started.   To
              switch  this  display  to the current one, the following command
              may be used:

         gpg-connect-agent updatestartuptty /bye

       Although all GnuPG components try to start  the  gpg-agent  as  needed,
       this  is  not  possible  for  the ssh support because ssh does not know
       about it.  Thus if no GnuPG tool which accesses the agent has been run,
       there is no guarantee that ssh is able to use gpg-agent for authentica-
       tion.  To fix this you may start gpg-agent if needed using this  simple
       command:

         gpg-connect-agent /bye

       Adding the --verbose shows the progress of starting the agent.

       The  --enable-putty-support  is only available under Windows and allows
       the use of gpg-agent with the ssh implementation putty.  This is  simi-
       lar  to  the regular ssh-agent support but makes use of Windows message
       queue as required by putty.

         unset SSH_AGENT_PID
         if [ "${gnupg_SSH_AUTH_SOCK_by:-0}" -ne $$ ]; then
           export SSH_AUTH_SOCK="${HOME}/.gnupg/S.gpg-agent.ssh"
         fi

FILES
       There  are  a  few  configuration files needed for the operation of the
       agent. By default they may all be found in the current  home  directory
       (see: [option --homedir]).

       gpg-agent.conf
                This is the standard configuration file read by gpg-agent on
                startup.  It may contain any valid long option; the leading
                two dashes may not be entered and the option may not be abbre-
              viated.
                This file is also read after a SIGHUP however only a few
                options will actually have an effect.  This default  name  may
              be
                changed on the command line (see: [option --options]).
                You should backup this file.

       trustlist.txt
                This  is  the  list  of  trusted keys.  You should backup this
              file.

                Comment lines, indicated by a leading hash mark,  as  well  as
              empty
                lines are ignored.  To mark a key as trusted you need to enter
              its
                fingerprint followed by  a  space  and  a  capital  letter  S.
              Colons
                may optionally be used to separate the bytes of a fingerprint;
              this
                allows to cut and paste the fingerprint  from  a  key  listing
              output.  If
                the line is prefixed with a ! the key is explicitly marked as
                not trusted.

                Here  is  an  example  where two keys are marked as ultimately
              trusted
                and one as not trusted:

                  .RS 2
                # CN=Wurzel ZS 3,O=Intevation GmbH,C=DE
                A6935DD34EF3087973C706FC311AA2CCF733765B S

                # CN=PCA-1-Verwaltung-02/O=PKI-1-Verwaltung/C=DE
                DC:BD:69:25:48:BD:BB:7E:31:6E:BB:80:D3:00:80:35:D4:F8:A6:CD S

                # CN=Root-CA/O=Schlapphuete/L=Pullach/C=DE
                !14:56:98:D3:FE:9C:CA:5A:31:6E:BC:81:D3:11:4E:00:90:A3:44:C2 S
                .fi

       Before entering a key into this file, you need to ensure its
       This global list is also used if the local list is not available.

       It is possible to add further flags after the S for use by the
       caller:

              relax  Relax checking of some root certificate requirements.  As of now this
                     flag allows the use of root certificates with a missing basicConstraints
                     attribute (despite that it is a MUST for CA certificates) and disables
                     CRL checking for the root certificate.

              cm     If validation of a certificate finally issued by a CA with this flag set
                     fails, try again using the chain validation model.

       sshcontrol
              This file is used when support for the secure shell agent protocol has
              been enabled (see: [option --enable-ssh-support]). Only keys present in
              this file are used in the SSH protocol.  You should backup this file.

              The ssh-add tool may be used to add new entries to this file;
              you may also add them manually.  Comment lines, indicated by a leading
              hash mark, as well as empty lines are ignored.  An entry starts with
              optional whitespace, followed by the keygrip of the key given as 40 hex
              digits, optionally followed by the caching TTL in seconds and another
              optional field for arbitrary flags.  A non-zero TTL overrides the global
              default as set by --default-cache-ttl-ssh.

              The only flag support is confirm.  If this flag is found for a
              key, each use of the key will pop up a pinentry to confirm the use of
              that key.  The flag is automatically set if a new key was loaded into
              gpg-agent using the option -c of the ssh-add
              command.

              The keygrip may be prefixed with a ! to disable an entry entry.

              The following example lists exactly one key.  Note that keys available
              through a OpenPGP smartcard in the active smartcard reader are
              implicitly added to this list; i.e. there is no need to list them.

                # Key added on: 2011-07-20 20:38:46
                # Fingerprint:  5e:8d:c4:ad:e7:af:6e:27:8a:d6:13:e4:79:ad:0b:81
                34B62F25E277CF13D3C6BCEBFD3F85D08F0A864B 0 confirm

       private-keys-v1.d/

                This is the directory where gpg-agent stores the private keys.
              Each
                key  is  stored in a file with the name made up of the keygrip
              and the
                suffix 'key'.  You should backup all files in this directory
                and take great care to keep this backup closed away.

              Note that on larger installations, it is useful  to  put  prede-
              fined files into the directory '/etc/skel/.gnupg2' so that newly
              created users start up with a working configuration.  For exist-
              verbose, debug, debug-all, debug-level, debug-pinentry, no-grab,
              pinentry-program,   pinentry-invisible-char,  default-cache-ttl,
              max-cache-ttl,   ignore-cache-for-signing,    no-allow-external-
              cache,   allow-emacs-pinentry,  no-allow-mark-trusted,  disable-
              scdaemon,  and  disable-check-own-socket.   scdaemon-program  is
              also  supported  but  due  to  the current implementation, which
              calls the scdaemon only once, it is not of much use  unless  you
              manually kill the scdaemon.

       SIGTERM
              Shuts  down the process but waits until all current requests are
              fulfilled.  If the process has received 3 of these  signals  and
              requests are still pending, a shutdown is forced.

       SIGINT Shuts down the process immediately.

       SIGUSR1
              Dump internal information to the log file.

       SIGUSR2
              This signal is used for internal purposes.

SEE ALSO
       gpg2(1), gpgsm(1), gpg-connect-agent(1), scdaemon(1)

       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

         info gnupg

       should  give  you access to the complete manual including a menu struc-
       ture and an index.

GnuPG 2.1.11                      2016-01-21                      GPG-AGENT(1)
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