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       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


       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 usual way to run the agent is from the ~/.xsession file:

         eval $(gpg-agent --daemon)

       If you don't use an X server, you can also put this into  your  regular
       startup  file  ~/.profile  or  .bash_profile.   It  is  best not to run
       multiple instance of the gpg-agent, so you should make sure  that  only
       one  is  running:  gpg-agent  uses  an  environment  variable to inform
       clients about the communication parameters. You can write  the  content
       of  this  environment  variable  to  a  file so that you can test for a
       running agent.  Here is an example using Bourne shell syntax:

         gpg-agent --daemon --enable-ssh-support \
                   --write-env-file "${HOME}/.gpg-agent-info"

       This code should only be run once per user session to initially fire up
       the agent.  In the example the optional support for the included Secure
       Shell agent is enabled and the information about the agent  is  written
       to  a  file  in  the  HOME  directory.   Note that by running gpg-agent
       without arguments you may test whether an  agent  is  already  running;
       however  such  a  test  may  lead  to  a race condition, thus it is not

       The second script needs to be run for each interactive session:

         if [ -f "${HOME}/.gpg-agent-info" ]; then
           . "${HOME}/.gpg-agent-info"
           export GPG_AGENT_INFO
           export SSH_AUTH_SOCK
           export SSH_AGENT_PID

       It reads the data out of the file and exports the  variables.   If  you
       don't  use Secure Shell, you don't need the last two export statements.

       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
       output of the  tty  command.   For  W32  systems  this  option  is  not

       Please  make  sure  that  a  proper pinentry program has been installed
       under the default filename (which  is  system  dependant)  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.


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

              Print  the  program version and licensing information.  Not that
              you can abbreviate this command.


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

              Print  a  list  of all available options and commands.  Not that
              you can abbreviate this command.

              Run in server mode and wait for  commands  on  the  stdin.   The
              default  mode  is  to  create  a  socket and listen for commands

       --daemon [command line]
              Start the gpg-agent as a daemon; that is,  detach  it  from  the
              console  and run it in the background.  Because gpg-agent prints
              out important information required for further use, a common way
              of  invoking  gpg-agent  is: eval $(gpg-agent --daemon) to setup
              the  environment  variables.   The  option  --write-env-file  is
              another  way  commonly  used  to  do  this.   Yet another way is
              creating 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; if you exit from  this  shell,  gpg-
              agent terminates as well.


       --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.

       --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


              Outputs  additional information while running.  You can increase
              the verbosity by giving several verbose commands to gpgsm,  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  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

              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.

              Don't detach the process  from  the  console.   This  is  mainly
              useful 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
              correct in almost all cases.

       --write-env-file file
              Often it is required to connect to the agent from a process  not
              being an inferior of gpg-agent and thus the environment variable
              with the socket name is not available.  To help setting up those
              variables  in  other  sessions, this option may be used to write
              the information into file.  If file is not specified the default
              name  '${HOME}/.gpg-agent-info'  will  be  used.   The format is
              suitable to be evaluated by a Bourne shell like in  this  simple

         eval $(cat file)
         eval $(cut -d= -f 1 < file | xargs echo export)

              Tell  the  pinentry  not  to  grab the keyboard and mouse.  This
              option should  in  general  not  be  used  to  avoid  X-sniffing

       --log-file file
              Append  all  logging  output  to  file.  This is very helpful in
              seeing what the agent actually does.

              Allow clients to mark keys as trusted, i.e. put  them  into  the
              'trustlist.txt' file.  This is by default not allowed to make it
              harder for users to inadvertently accept Root-CA keys.

              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.

       --default-cache-ttl-ssh n
              Set the time a cache entry used for  SSH  keys  is  valid  to  n
              seconds.  The default is 1800 seconds.

       --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
              accessed recently.  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.  The default is 2 hours (7200

              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
              warning 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-program filename
              Use   program  filename  as  the  PIN  entry.   The  default  is
              installation dependent and  can  be  shown  with  the  --version

       --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  --version

              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.


              By enabling this option gpg-agent  will  listen  on  the  socket
              named  'S.gpg-agent',  located  in  the  home directory, and not
              create a random  socket  below  a  temporary  directory.   Tools
              connecting  to  gpg-agent  should  first  try  to connect to the
              socket given in environment  variable  GPG_AGENT_INFO  and  then
              fall  back  to  this socket.  This option may not be used if the
              home directory is mounted as a remote file system.   Note,  that
              --use-standard-socket is the default on Windows systems.

       --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.


              Enable emulation of 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
              possible 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
              necessary for decrypting the stored key.   Since  the  ssh-agent
              protocol  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:

         echo UPDATESTARTUPTTY | gpg-connect-agent

       All  the long options may also be given in the configuration file after
       stripping off the two leading dashes.


       The usual way to invoke gpg-agent is

         $ eval $(gpg-agent --daemon)

       An alternative way is by replacing ssh-agent with  gpg-agent.   If  for
       example  ssh-agent  is  started as part of the Xsession initialization,
       you may simply replace ssh-agent by a script like:


         exec /usr/local/bin/gpg-agent --enable-ssh-support --daemon \
               --write-env-file ${HOME}/.gpg-agent-info "$@"

       and add something like (for Bourne shells)

           if [ -f "${HOME}/.gpg-agent-info" ]; then
             . "${HOME}/.gpg-agent-info"
             export GPG_AGENT_INFO
             export SSH_AUTH_SOCK
             export SSH_AGENT_PID

       to your shell initialization file (e.g. '~/.bashrc').


       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
                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;
                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
                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 allowing interactive
       updates of this file by using the see: [option --allow-mark-trusted].
       This is however not as secure as maintaining this file manually.  It is
       even 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.  This is for
                     example required if the certificate is missing the basicConstraints
                     attribute (despite that it is a MUST for CA certificates).

              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 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.

                .RS 2
                # Key added on 2005-02-25 15:08:29
                5A6592BF45DC73BD876874A28FD4639282E29B52 0


                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 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,  no-grab,  pinentry-
              program,  default-cache-ttl,  max-cache-ttl,   ignore-cache-for-
              signing,  allow-mark-trusted  and  disable-scdaemon.   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.


       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

         info gnupg

       should give  you  access  to  the  complete  manual  including  a  menu
       structure and an index.