The gpg-preset-passphrase is a utility to seed the internal
cache of a running gpg-agent with passphrases. It is mainly
useful for unattended machines, where the usual pinentry tool
may not be used and the passphrases for the to be used keys are given at
Passphrases set with this utility dont expire unless the
--forget option is used to explicitly clear them from the
cache --- or gpg-agent is either restarted or reloaded (by
sending a SIGHUP to it). Nite that the maximum cache time as set with
--max-cache-ttl is still honored. It is necessary to allow
this passphrase presetting by starting gpg-agent with the
gpg-preset-passphrase is invoked this way:
gpg-preset-passphrase [options] [command] cacheid
cacheid is either a 40 character keygrip of hexadecimal
characters identifying the key for which the passphrase should be set
or cleared. The keygrip is listed along with the key when running the
command: gpgsm --dump-secret-keys. Alternatively an arbitrary
string may be used to identify a passphrase; it is suggested that such
a string is prefixed with the name of the application (e.g
One of the following command options must be given:
Preset a passphrase. This is what you usually will
use. gpg-preset-passphrase will then read the passphrase from
Flush the passphrase for the given cache ID from the cache.
The following additional options may be used:
Output additional information while running.
Instead of reading the passphrase from stdin, use the supplied
string as passphrase. Note that this makes the passphrase visible
for other users.
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
should give you access to the complete manual including a menu structure
and an index.