sm: Lookup missing issuers first using authorityInfoAccess.
* sm/call-dirmngr.c (gpgsm_dirmngr_lookup): Add optional arg URL and adjust all callers. * sm/certchain.c (oidstr_caIssuers): New. (struct find_up_store_certs_s): Add additional fields. (find_up_store_certs_cb): Store the fingerprint. (find_up_via_auth_info_access): New. (find_up): Try the AIA URI first.
Note that --auto-issuer-key-retrieve is required to use that.
- GnuPG-bug-id: T4898
- Signed-off-by: Werner Koch <wk@gnupg.org>