.\" Created from Texinfo source by yat2m 1.31
.TH GPG-AGENT 1 2020-03-18 "GnuPG 2.2.20" "GNU Privacy Guard 2.2"
.SH NAME
.B gpg-agent
\- Secret key management for GnuPG
.SH SYNOPSIS
.B  gpg-agent
.RB [ \-\-homedir
.IR dir ]
.RB [ \-\-options
.IR file ]
.RI [ options ]
.br
.B  gpg-agent
.RB [ \-\-homedir
.IR dir ]
.RB [ \-\-options
.IR file ]
.RI [ options ]
.B  \-\-server
.br
.B  gpg-agent
.RB [ \-\-homedir
.IR dir ]
.RB [ \-\-options
.IR file ]
.RI [ options ]
.B  \-\-daemon
.RI [ command_line ]

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

The agent is automatically started on demand by \fBgpg\fR,
\fBgpgsm\fR, \fBgpgconf\fR, or \fBgpg-connect-agent\fR.
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:


.RS 2
.nf
gpg-connect-agent /bye
.fi
.RE


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

.RS 2
.nf
gpgconf --kill gpg-agent
.fi
.RE


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

.RS 2
.nf
GPG_TTY=$(tty)
export GPG_TTY
.fi
.RE


It is important that this environment variable always reflects the
output of the \fBtty\fR 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 \fBpinentry-program\fR to specify the full name of that program.
It is often useful to install a symbolic link from the actual used
pinentry (e.g. \(oq\fI/usr/bin/pinentry-gtk\fR\(cq) to the expected
one (e.g. \(oq\fI/usr/bin/pinentry\fR\(cq).



.SH COMMANDS

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

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

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

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

.TP
.B  --server
Run in server mode and wait for commands on the \fBstdin\fR.  The
default mode is to create a socket and listen for commands there.

.TP
.B  --daemon [\fIcommand line\fR]
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: \fBgpg-agent --daemon /bin/sh\fR.  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.

.TP
.B  --supervised
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 \fBLISTEN_FDNAMES\fR (see
sd_listen_fds(3) on some Linux distributions for more information on
this convention).
.P

.SH OPTIONS

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



.TP
.B  --options \fIfile\fR
Reads configuration from \fIfile\fR instead of from the default
per-user configuration file.  The default configuration file is named
\(oq\fIgpg-agent.conf\fR\(cq and expected in the \(oq\fI.gnupg\fR\(cq directory
directly below the home directory of the user.  This option is ignored
if used in an options file.


.TP
.B  --homedir \fIdir\fR
Set the name of the home directory to \fIdir\fR. If this option is not
used, the home directory defaults to \(oq\fI~/.gnupg\fR\(cq.  It is only
recognized when given on the command line.  It also overrides any home
directory stated through the environment variable \(oq\fIGNUPGHOME\fR\(cq or
(on Windows systems) by means of the Registry entry
\fIHKCU\\Software\\GNU\\GnuPG:HomeDir\fR.

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.

To install GnuPG as a portable application under Windows, create an
empty file named \(oq\fIgpgconf.ctl\fR\(cq in the same directory as the tool
\(oq\fIgpgconf.exe\fR\(cq.  The root of the installation is then that
directory; or, if \(oq\fIgpgconf.exe\fR\(cq has been installed directly below
a directory named \(oq\fIbin\fR\(cq, its parent directory.  You also need to
make sure that the following directories exist and are writable:
\(oq\fIROOT/home\fR\(cq for the GnuPG home and \(oq\fIROOT/var/cache/gnupg\fR\(cq
for internal cache files.


.TP
.B  -v
.TP
.B  --verbose
Outputs additional information while running.
You can increase the verbosity by giving several
verbose commands to \fBgpg-agent\fR, such as \(aq-vv\(aq.

.TP
.B  -q
.TP
.B  --quiet
Try to be as quiet as possible.

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

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

.TP
.B  --debug-level \fIlevel\fR
Select the debug level for investigating problems. \fIlevel\fR may be
a numeric value or a keyword:

.RS
.TP
.B  none
No debugging at all.  A value of less than 1 may be used instead of
the keyword.
.TP
.B  basic
Some basic debug messages.  A value between 1 and 2 may be used
instead of the keyword.
.TP
.B  advanced
More verbose debug messages.  A value between 3 and 5 may be used
instead of the keyword.
.TP
.B  expert
Even more detailed messages.  A value between 6 and 8 may be used
instead of the keyword.
.TP
.B  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 used.
.RE

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.

.TP
.B  --debug \fIflags\fR
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:

.RS
.TP
.B  0  (1)
X.509 or OpenPGP protocol related data
.TP
.B  1  (2)
values of big number integers
.TP
.B  2  (4)
low level crypto operations
.TP
.B  5  (32)
memory allocation
.TP
.B  6  (64)
caching
.TP
.B  7  (128)
show memory statistics
.TP
.B  9  (512)
write hashed data to files named \fBdbgmd-000*\fR
.TP
.B  10 (1024)
trace Assuan protocol
.TP
.B  12 (4096)
bypass all certificate validation
.RE

.TP
.B  --debug-all
Same as \fB--debug=0xffffffff\fR

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

.TP
.B  --debug-quick-random
This option inhibits the use of the very secure random quality level
(Libgcrypt’s \fBGCRY_VERY_STRONG_RANDOM\fR) and degrades all request
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
\fBrngd\fR to fill the kernel's entropy pool with lower quality
random data.  \fBrngd\fR is typically provided by the
\fBrng-tools\fR package.  It can be run as follows: \(aqsudo
rngd -f -r /dev/urandom\(aq.

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

.TP
.B  --no-detach
Don't detach the process from the console.  This is mainly useful for
debugging.

.TP
.B  -s
.TQ
.B  --sh
.TQ
.B  -c
.TQ
.B  --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 \fBSHELL\fR which is correct in almost all
cases.


.TP
.B  --grab
.TQ
.B  --no-grab
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 \fB--grab\fR overrides an used option \fB--no-grab\fR.
The default is \fB--no-grab\fR.


.TP
.B  --log-file \fIfile\fR
Append all logging output to \fIfile\fR.  This is very helpful in
seeing what the agent actually does. Use \(oq\fIsocket://\fR\(cq to log to
socket.  If neither a log file nor a log file descriptor has been set
on a Windows platform, the Registry entry
\fBHKCU\\Software\\GNU\\GnuPG:DefaultLogFile\fR, if set, is used to
specify the logging output.



.TP
.B  --no-allow-mark-trusted
Do not allow clients to mark keys as trusted, i.e. put them into the
\(oq\fItrustlist.txt\fR\(cq file.  This makes it harder for users to inadvertently
accept Root-CA keys.


.TP
.B  --allow-preset-passphrase
This option allows the use of \fBgpg-preset-passphrase\fR to seed the
internal cache of \fBgpg-agent\fR with passphrases.


.TP
.B  --no-allow-loopback-pinentry
.TP
.B  --allow-loopback-pinentry
Disallow or allow clients to use the loopback pinentry features; see
the option \fBpinentry-mode\fR for details.  Allow is the default.

The \fB--force\fR option of the Assuan command \fBDELETE_KEY\fR
is also controlled by this option: The option is ignored if a loopback
pinentry is disallowed.

.TP
.B  --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.

.TP
.B  --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.

.TP
.B  --ignore-cache-for-signing
This option will let \fBgpg-agent\fR 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.

.TP
.B  --default-cache-ttl \fIn\fR
Set the time a cache entry is valid to \fIn\fR 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
\fBmax-cache-ttl\fR.  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.

.TP
.B  --default-cache-ttl-ssh \fIn\fR
Set the time a cache entry used for SSH keys is valid to \fIn\fR
seconds.  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 \fBmax-cache-ttl-ssh\fR.

.TP
.B  --max-cache-ttl \fIn\fR
Set the maximum time a cache entry is valid to \fIn\fR seconds.  After
this time a cache entry will be expired even if it has been accessed
recently or has been set using \fBgpg-preset-passphrase\fR.  The
default is 2 hours (7200 seconds).

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

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

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

.TP
.B  --min-passphrase-nonalpha \fIn\fR
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.

.TP
.B  --check-passphrase-pattern \fIfile\fR
Check the passphrase against the pattern given in \fIfile\fR.  When
entering a new passphrase matching one of these pattern a warning will
be displayed. \fIfile\fR 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.

.TP
.B  --max-passphrase-days \fIn\fR
Ask the user to change the passphrase if \fIn\fR days have passed since
the last change.  With \fB--enforce-passphrase-constraints\fR set the
user may not bypass this check.

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

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

.TP
.B  --pinentry-timeout \fIn\fR
This option asks the Pinentry to timeout after \fIn\fR 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 request.

.TP
.B  --pinentry-program \fIfilename\fR
Use program \fIfilename\fR as the PIN entry.  The default is
installation dependent.  With the default configuration the name of
the default pinentry is \(oq\fIpinentry\fR\(cq; if that file does not exist
but a \(oq\fIpinentry-basic\fR\(cq exist the latter is used.

On a Windows platform the default is to use the first existing program
from this list:
\(oq\fIbin\\pinentry.exe\fR\(cq,
\(oq\fI..\\Gpg4win\\bin\\pinentry.exe\fR\(cq,
\(oq\fI..\\Gpg4win\\pinentry.exe\fR\(cq,
\(oq\fI..\\GNU\\GnuPG\\pinentry.exe\fR\(cq,
\(oq\fI..\\GNU\\bin\\pinentry.exe\fR\(cq,
\(oq\fIbin\\pinentry-basic.exe\fR\(cq
where the file names are relative to the GnuPG installation directory.


.TP
.B  --pinentry-touch-file \fIfilename\fR
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 \fIfilename\fR.  The special name
\fB/dev/null\fR 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.


.TP
.B  --scdaemon-program \fIfilename\fR
Use program \fIfilename\fR as the Smartcard daemon.  The default is
installation dependent and can be shown with the \fBgpgconf\fR
command.

.TP
.B  --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.

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

.TP
.B  --use-standard-socket
.TQ
.B  --no-use-standard-socket
.TQ
.B  --use-standard-socket-p
Since GnuPG 2.1 the standard socket is always used.  These options
have no more effect.  The command \fBgpg-agent
--use-standard-socket-p\fR will thus always return success.

.TP
.B  --display \fIstring\fR
.TQ
.B  --ttyname \fIstring\fR
.TQ
.B  --ttytype \fIstring\fR
.TQ
.B  --lc-ctype \fIstring\fR
.TQ
.B  --lc-messages \fIstring\fR
.TQ
.B  --xauthority \fIstring\fR
These options are used with the server mode to pass localization
information.

.TP
.B  --keep-tty
.TQ
.B  --keep-display
Ignore requests to change the current \fBtty\fR or X window system's
\fBDISPLAY\fR variable respectively.  This is useful to lock the
pinentry to pop up at the \fBtty\fR or display you started the agent.

.TP
.B  --listen-backlog \fIn\fR
Set the size of the queue for pending connections.  The default is 64.


.TP
.B  --extra-socket \fIname\fR
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 \fIname\fR.

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 \fBgpg\fR 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.


.TP
.B  --enable-extended-key-format
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 unreadable 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.


.TP
.B  --enable-ssh-support
.TQ
.B  --enable-putty-support

The OpenSSH Agent protocol is always enabled, but \fBgpg-agent\fR
will only set the \fBSSH_AUTH_SOCK\fR 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 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:

.RS 2
.nf
gpg-connect-agent updatestartuptty /bye
.fi
.RE

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 authentication.  To fix
this you may start gpg-agent if needed using this simple command:

.RS 2
.nf
gpg-connect-agent /bye
.fi
.RE

Adding the \fB--verbose\fR shows the progress of starting the agent.

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


.TP
.B  --ssh-fingerprint-digest

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 SHA256.


.TP
.B  --auto-expand-secmem \fIn\fR
Allow Libgcrypt to expand its secure memory area as required.  The
optional value \fIn\fR 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 prefixes are allowed.
For an heavy loaded gpg-agent with many concurrent connection this
option avoids sign or decrypt errors due to out of secure memory error
returns.

.TP
.B  --s2k-calibration \fImilliseconds\fR
Change the default calibration time to \fImilliseconds\fR.  The given
value is capped at 60 seconds; a value of 0 resets to the compiled-in
default.  This option is re-read on a SIGHUP (or \fBgpgconf
--reload gpg-agent\fR) and the S2K count is then re-calibrated.

.TP
.B  --s2k-count \fIn\fR
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 \fB--s2k-calibration\fR.

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

.RS 2
.nf
gpg-connect-agent 'GETINFO s2k_count' /bye
gpg-connect-agent 'GETINFO s2k_time' /bye
.fi
.RE

To view the auto-calibrated count use:

.RS 2
.nf
gpg-connect-agent 'GETINFO s2k_count_cal' /bye
.fi
.RE


.P


.SH EXAMPLES

It is important to set the environment variable \fBGPG_TTY\fR in
your login shell, for example in the \(oq\fI~/.bashrc\fR\(cq init script:

.RS 2
.nf
  export GPG_TTY=$(tty)
.fi
.RE

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

.RS 2
.nf
unset SSH_AGENT_PID
if [ "${gnupg_SSH_AUTH_SOCK_by:-0}" -ne $$ ]; then
  export SSH_AUTH_SOCK="$(gpgconf --list-dirs agent-ssh-socket)"
fi
.fi
.RE



.SH 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]).


.TP
.B  gpg-agent.conf
  This is the standard configuration file read by \fBgpg-agent\fR on
  startup.  It may contain any valid long option; the leading
  two dashes may not be entered and the option may not be abbreviated.
  This file is also read after a \fBSIGHUP\fR 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.

.TP
.B  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 \fBS\fR.  Colons
  may optionally be used to separate the bytes of a fingerprint; this
  enables cutting and pasting the fingerprint from a key listing output.  If
  the line is prefixed with a \fB!\fR 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
.nf
  # 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
.RE
  
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 \fBinclude-default\fR will include a global
list of trusted certificates (e.g. \(oq\fI/etc/gnupg/trustlist.txt\fR\(cq).
This global list is also used if the local list is not available.

It is possible to add further flags after the \fBS\fR for use by the
caller:

.RS

.TP
.B  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.

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

.RE


.TP
.B  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 \fBssh-add\fR 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 \fB--default-cache-ttl-ssh\fR.

The only flag support is \fBconfirm\fR.  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
\fBgpg-agent\fR using the option \fB-c\fR of the \fBssh-add\fR
command.

The keygrip may be prefixed with a \fB!\fR 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.

.RS 2
.nf
       # 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
.fi
.RE

.TP
.B  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 \(oq\fIkey\fR\(cq.  You should backup all files in this directory
  and take great care to keep this backup closed away.


.P

Note that on larger installations, it is useful to put predefined
files into the directory \(oq\fI/etc/skel/.gnupg\fR\(cq 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]).




.SH SIGNALS
A running \fBgpg-agent\fR may be controlled by signals, i.e. using
the \fBkill\fR command to send a signal to the process.

Here is a list of supported signals:


.TP
.B  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: \fBquiet\fR,
\fBverbose\fR, \fBdebug\fR, \fBdebug-all\fR, \fBdebug-level\fR,
\fBdebug-pinentry\fR,
\fBno-grab\fR,
\fBpinentry-program\fR,
\fBpinentry-invisible-char\fR,
\fBdefault-cache-ttl\fR,
\fBmax-cache-ttl\fR, \fBignore-cache-for-signing\fR,
\fBs2k-count\fR,
\fBno-allow-external-cache\fR, \fBallow-emacs-pinentry\fR,
\fBno-allow-mark-trusted\fR, \fBdisable-scdaemon\fR, and
\fBdisable-check-own-socket\fR.  \fBscdaemon-program\fR 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.


.TP
.B  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.

.TP
.B  SIGINT
Shuts down the process immediately.

.TP
.B  SIGUSR1
Dump internal information to the log file.

.TP
.B  SIGUSR2
This signal is used for internal purposes.

.P


.SH SEE ALSO
\fBgpg\fR(1),
\fBgpgsm\fR(1),
\fBgpgconf\fR(1),
\fBgpg-connect-agent\fR(1),
\fBscdaemon\fR(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

.RS 2
.nf
info gnupg
.fi
.RE

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