gpg: Implement encryption to ADSKs.
* g10/getkey.c (get_pubkey_fromfile): Add optional arg r_keyblock. * g10/pkclist.c (find_and_check_key): Also encrypt to RENC subkeys. * g10/getkey.c (parse_key_usage): Make public. * g10/misc.c (openpgp_pk_algo_usage): Take PUBKEY_USAGE_RENC in account. * g10/packet.h (PKT_public_key): Change pubkey_usage from byte to u16. (PKT_user_id): Cosmetic fix: change help_key_usage from int to u16. * g10/sig-check.c (check_signature_metadata_validity): Handle time conflict for ADSKs.
This patch handles ADSK keys and encrypts to them. It does not yet
allow the creation of them. We backport this from master early to get
this part of the code out into the field.
- GnuPG-bug-id: T6395