scd:p15: Extract extended usage flagsand act upon them.
* scd/app-p15.c: Add a couple of oid constants. (struct cdf_object_s): Replace fields image and imagelen by cert. (struct prkdf_object_s): Add extusage flags (send_keypairinfo): Use them. (cdf_object_from_certid): Factor parts out to ... (cdf_object_from_objid): new function. (read_ef_prkdf): Move info printing to ... (read_p15_info): here. Fill the extusage flags. (readcert_by_cdf): Cache the ksba cert object instead of the binary cert. * scd/app.c (select_additional_application): Fix a log_debug call. (scd_update_reader_status_file): Ditto.
This allows us to return only KEYPAIRINFO lines for keys we can