core: Fix expiration time handling when creating keys.
* NEWS: Update. * doc/gpgme.texi (gpgme_op_createkey): Clarify the meaning of the 'expire' parameter. (GPGME_CREATE_NOEXPIRE): Document new flag. (gpgme_op_createsubkey): Clarify the meaning of the 'expire' parameter. * src/engine-gpg.c (gpg_add_algo_usage_expire): Fix handling of the expiration time. * src/gpgme.h.in (GPGME_CREATE_NOEXPIRE): New macro.
Previously, the documentation stated that the expiration time was an
absolute timestamp. However, this value was passed using the
'seconds=N' syntax to GnuPG which specifies the expiration time in
seconds relative to the creation time. Fix the documentation.
Furthermore, the documentation stated that using 0 results in keys
that do not expire. This was communicated to GnuPG by using the
implicit default. However, as of GnuPG 2.1.17, the default was
changed to create keys that expire within a reasonable timespan.
Fix this discrepancy by aligning the behavior with recent GnuPG
versions: 0 means use a reasonable default, and introduce a flag that
can be used to create keys that do not expire. Communicate this
explicitly to GnuPG.
- Signed-off-by: Justus Winter <firstname.lastname@example.org>