GPG-AGENT(1)                 GNU Privacy Guard 2.2                GPG-AGENT(1)

       gpg-agent - Secret key management for GnuPG

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

       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

       If  you want to manually terminate the currently-running agent, you can
       safely do so with:

         gpgconf --kill gpg-agent

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

         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  un-
       der  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 pinentry (e.g.
       '/usr/bin/pinentry-gtk') to the  expected  one  (e.g.  '/usr/bin/pinen-

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

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

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

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

              Run  in server mode and wait for commands on the stdin.  The de-
              fault mode is to create a socket and listen for commands there.

       --daemon [command line]
              Start the gpg-agent as a daemon; that is,  detach  it  from  the
              console and run it in the background.

              As  an  alternative  you  may create a new process as a child of
              gpg-agent: gpg-agent --daemon /bin/sh.  This way you get  a  new
              shell  with  the environment setup properly; after you exit from
              this shell, gpg-agent terminates within a few seconds.

              Run in the foreground, sending logs by default  to  stderr,  and
              listening  on  provided  file descriptors, which must already be
              bound to listening sockets.  This command is useful when running
              under  systemd  or  other  similar  process supervision schemes.
              This option is not supported on Windows.

              In --supervised mode, different file descriptors can be provided
              for  use  as different socket types (e.g. ssh, extra) as long as
              they are identified in the environment  variable  LISTEN_FDNAMES
              (see  sd_listen_fds(3)  on some Linux distributions for more in-
              formation on this convention).

       Options may either be used on the command line or, after stripping  off
       the two leading dashes, in the configuration file.

       --options file
              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.  This  option  is
              ignored if used in an options file.

       --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 en-
              try 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 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 be-
              low 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/gnupg' for internal cache files.


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


              Try to be as quiet as possible.

              Don't  invoke  a  pinentry or do any other thing requiring human

       --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.

              basic  Some basic debug messages.  A value between 1 and  2  may
                     be used instead of the keyword.

                     More verbose debug messages.  A value between 3 and 5 may
                     be used instead of the keyword.

              expert Even more detailed messages.  A value between 6 and 8 may
                     be used instead of the keyword.

              guru   All  of  the  debug messages you can get. A value greater
                     than 8 may be used instead of the keyword.  The  creation
                     of  hash  tracing files is only enabled if the keyword is

       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  behavior  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

              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.

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

              On GNU/Linux, another way to quickly generate insecure  keys  is
              to use rngd to fill the kernel's entropy pool with lower quality
              random data.  rngd is typically provided by the rng-tools  pack-
              age.  It can be run as follows: 'sudo rngd -f -r /dev/urandom'.

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

              Don't  detach the process from the console.  This is mainly use-
              ful for debugging.

       --csh  Format the info output in daemon mode for use with the  standard
              Bourne  shell  or  the  C-shell respectively.  The default is to
              guess it based on the environment variable SHELL which  is  cor-
              rect in almost all cases.

              Tell  the  pinentry to grab the keyboard and mouse.  This option
              should be used on X-Servers to avoid X-sniffing attacks. Any use
              of  the  option  --grab overrides an used option --no-grab.  The
              default is --no-grab.

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

              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 in-
              advertently accept Root-CA keys.

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


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

              The --force option of the Assuan command DELETE_KEY is also con-
              trolled by this option: The option  is  ignored  if  a  loopback
              pinentry is disallowed.

              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 em-
              ploys 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

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

              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  behavior 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 en-
              try's timer is reset.  To set an entry's maximum  lifetime,  use
              max-cache-ttl.   Note  that  a cached passphrase may not evicted
              immediately from memory if no client requests a cache operation.
              This  is  due to an internal housekeeping function which is only
              run every few seconds.

       --default-cache-ttl-ssh n
              Set the time a cache entry used for SSH keys is valid to n  sec-
              onds.   The default is 1800 seconds.  Each time a cache entry is
              accessed, the entry's timer is reset.  To set an entry's maximum
              lifetime, use max-cache-ttl-ssh.

       --max-cache-ttl n
              Set the maximum time a cache entry is valid to n seconds.  After
              this time a cache entry will be expired even if it has been  ac-
              cessed  recently  or  has  been set using gpg-preset-passphrase.
              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  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.

              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
              value  in  this  case.  A Pinentry may or may not honor this re-

       --pinentry-program filename
              Use program filename as the PIN entry.  The default is installa-
              tion  dependent.  With the default configuration the name of the
              default pinentry is 'pinentry'; if that file does not exist  but
              a 'pinentry-basic' exist the latter is used.

              On  a  Windows platform the default is to use the first existing
              program      from      this      list:       'bin\pinentry.exe',
              '..\Gpg4win\bin\pinentry.exe',        '..\Gpg4win\pinentry.exe',
              '..\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-

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

              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

              Since  GnuPG  2.1 the standard socket is always used.  These op-
              tions 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

              Ignore requests to change the current tty or X  window  system's
              DISPLAY  variable  respectively.   This  is  useful  to lock the
              pinentry to pop up at the tty or display you started the agent.

       --listen-backlog n
              Set the size of the queue for pending connections.  The  default
              is 64.

       --extra-socket name
              The  extra socket is created by default, you may use this option
              to change the name of the socket.  To disable  the  creation  of
              the socket use ``none'' or ``/dev/null'' for name.

              Also listen on native gpg-agent connections on the given socket.
              The intended use for this extra socket is to setup a Unix domain
              socket  forwarding  from  a remote machine to this socket on the
              local machine.  A gpg running on the  remote  machine  may  then
              connect  to  the local gpg-agent and use its private keys.  This
              enables decrypting or signing data on a remote  machine  without
              exposing the private keys to the remote machine.

              This  option  creates  keys  in the extended private key format.
              Changing the passphrase of a key will also convert  the  key  to
              that  new  format.  Using this option makes the private keys un-
              readable for gpg-agent versions before 2.1.12.  The advantage of
              the extended private key format is that it is text based and can
              carry additional meta data.  Note that this option also  changes
              the key protection format to use OCB mode.


              The OpenSSH Agent protocol is always enabled, but gpg-agent will
              only set the SSH_AUTH_SOCK variable if this flag is given.

              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

         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.


              Select the digest algorithm used  to  compute  ssh  fingerprints
              that  are  communicated  to  the user, e.g. in pinentry dialogs.
              OpenSSH has transitioned from  using  MD5  to  the  more  secure

       --auto-expand-secmem n
              Allow  Libgcrypt  to  expand its secure memory area as required.
              The optional value n is a non-negative integer with a  suggested
              size in bytes of each additionally allocated secure memory area.
              The value is rounded up to the next 32 KiB; usual C  style  pre-
              fixes are allowed.  For an heavy loaded gpg-agent with many con-
              current connection this option avoids sign or decrypt errors due
              to out of secure memory error returns.

       --s2k-calibration milliseconds
              Change  the default calibration time to milliseconds.  The given
              value is capped at 60 seconds; a value of 0 resets to  the  com-
              piled-in  default.   This option is re-read on a SIGHUP (or gpg-
              conf --reload gpg-agent) and the  S2K  count  is  then  re-cali-

       --s2k-count n
              Specify  the  iteration  count  used  to protect the passphrase.
              This option can be used to override the auto-calibration done by
              default.   The  auto-calibration computes a count which requires
              by default 100ms to mangle a given passphrase.  See also  --s2k-

              To  view  the actually used iteration count and the milliseconds
              required for an S2K operation use:

         gpg-connect-agent 'GETINFO s2k_count' /bye
         gpg-connect-agent 'GETINFO s2k_time' /bye

       To view the auto-calibrated count use:

         gpg-connect-agent 'GETINFO s2k_count_cal' /bye

       It is important to set the environment variable GPG_TTY in  your  login
       shell, for example in the '~/.bashrc' init script:

           export GPG_TTY=$(tty)

       If  you  enabled the Ssh Agent Support, you also need to tell ssh about
       it by adding this to your init script:

         unset SSH_AGENT_PID
         if [ "${gnupg_SSH_AUTH_SOCK_by:-0}" -ne $$ ]; then
           export SSH_AUTH_SOCK="$(gpgconf --list-dirs agent-ssh-socket)"

       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]).

                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-
                This file is also read after a SIGHUP however only a few
                options  will  actually have an effect.  This default name may
                changed on the command line (see: [option --options]).
                You should backup this file.

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

                Comment  lines,  indicated  by a leading hash mark, as well as
                lines are ignored.  To mark a key as trusted you need to enter
                fingerprint  followed  by  a  space  and  a  capital letter S.
                may optionally be used to separate the bytes of a fingerprint;
                enables cutting and pasting 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
                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

       Before entering a key into this file, you need to ensure its
       authenticity.  How to do this depends on your organisation; your
       administrator might have already entered those keys which are deemed
       trustworthy enough into this file.  Places where to look for the
       fingerprint of a root certificate are letters received from the CA or
       the website of the CA (after making 100% sure that this is indeed the
       website of that CA).  You may want to consider disallowing interactive
       updates of this file by using the [option --no-allow-mark-trusted].
       It might even be advisable to change the permissions to read-only so
       that this file can't be changed inadvertently.

       As a special feature a line include-default will include a global
       list of trusted certificates (e.g. '/etc/gnupg/trustlist.txt').
       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

              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.

              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

              The keygrip may be prefixed with a ! to disable an 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


                This is the directory where gpg-agent stores the private keys.
                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 predefined files
       into the directory '/etc/skel/.gnupg' so that newly created users start
       up with a working configuration.  For existing users the a small helper
       script is provided to create these files (see: [addgnupghome]).

       A running gpg-agent may be controlled by signals, i.e. using  the  kill
       command to send a signal to the process.

       Here is a list of supported signals:

       SIGHUP This  signal  flushes  all cached passphrases and if the program
              has been started with a configuration  file,  the  configuration
              file  is  read  again.  Only certain options are honored: quiet,
              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, s2k-count, no-allow-ex-
              ternal-cache,  allow-emacs-pinentry, no-allow-mark-trusted, dis-
              able-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.

              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.

              Dump internal information to the log file.

              This signal is used for internal purposes.

       gpg(1), gpgsm(1), gpgconf(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

         info gnupg

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

GnuPG 2.2.12                      2018-12-11                      GPG-AGENT(1)

Man(1) output converted with man2html
list of all man pages