scd: Add handling of Ed448 key.
* scd/app-openpgp.c (struct app_local_s): Add ecc.algo field. (send_key_attr): Use ecc.algo field. (ecc_read_pubkey): Use ecc.algo field. (ecc_writekey): Ed448 means EdDSA. (parse_algorithm_attribute): Set ecc.algo field from card. Add checking for Ed25519 for ECC_FLAG_DJB_TWEAK flag.
There used to be a possible support of Ed25519 with ECDSA, (instead of
EdDSA). To distinguish key for Ed25519 for EdDSA, we use the
flag: (flags eddsa). Ed448 has no support for ECDSA and defaults to
EdDSA even if no such flag.
(cherry picked from commit b743942a9719be59f1da67cd338248fe7ee5aeab)
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>