gpgme_key_ref acquires an additional reference for
the key key.
gpgme_key_unref releases a reference for the key
key. If this was the last reference, the key will be destroyed
and all resources associated to it will be released.
gpgme_op_setexpire sets the expiration time of
the key key or of the specified subkeys.
This function requires at least version 2.1.22 of GnuPG.
key specifies the key to operate on.
expires specifies the expiration time in seconds from now. To be similar to other usages where expiration times are provided in unsigned long this is similar to the key creation date and so it is in seconds from NOW.
The common case is to use 0 to not set an expiration time.
Note that this parameter takes an unsigned long value and not
time_t to avoid problems on systems which use a signed
time_t. Note further that the OpenPGP protocol
uses 32 bit values for timestamps and thus can
only encode dates up to the year 2106.
subfprs selects the subkey(s) for which the expiration time
should be set. If subfprs is set to
NULL, then the
expiration time of the primary key is set. If subfprs is
an asterisk (
*), then the expiration times of all non-revoked
and not yet expired subkeys are set. To select more than one subkey
put all subkey fingerprints into one string separated by linefeeds
reserved is reserved for later use and must be
gpgme_op_setexpire_start initiates a
gpgme_op_setexpire operation; see there for details. It must
be completed by calling
gpgme_wait on the context.
See Waiting For Completion.