gpg: Rework ECC support and add experimental support for Ed25519.
* agent/findkey.c (key_parms_from_sexp): Add algo name "ecc". (agent_is_dsa_key): Ditto. (agent_is_eddsa_key): New. Not finished, though. * agent/pksign.c (do_encode_eddsa): New. (agent_pksign_do): Use gcry_log_debug functions. * agent/protect.c (agent_protect): Parse a flags parameter. * g10/keygen.c (gpg_curve_to_oid): Move to ... * common/openpgp-oid.c (openpgp_curve_to_oid): here and rename. (oid_ed25519): New. (openpgp_oid_is_ed25519): New. (openpgp_oid_to_curve): New. * common/t-openpgp-oid.c (test_openpgp_oid_is_ed25519): New. * g10/build-packet.c (gpg_mpi_write): Write the length header also for opaque MPIs. (gpg_mpi_write_nohdr): New. (do_key): Use gpg_mpi_write_nohdr depending on algorithm. (do_pubkey_enc): Ditto. * g10/ecdh.c (pk_ecdh_encrypt_with_shared_point): Use gpg_mpi_write_nohdr. * g10/export.c (transfer_format_to_openpgp): * g10/keygen.c (ecckey_from_sexp): Return the error. (gen_ecc): Repalce arg NBITS by CURVE. (read_parameter_file): Add keywords "Key-Curve" and "Subkey-Curve". (ask_curve): New. (generate_keypair, generate_subkeypair): Use ask_curve. (do_generate_keypair): Also pass curve name. * g10/keylist.c (list_keyblock_print, list_keyblock_colon): Print curve name. * g10/parse-packet.c (mpi_read): Remove workaround for Libcgrypt < 1.5. (parse_key): Fix ECC case. Print the curve name. * g10/pkglue.c (mpi_from_sexp): Rename to get_mpi_from_sexp. (pk_verify, pk_check_secret_key): Add special case for Ed25519. * g10/seskey.c (encode_md_value): Ditto. * g10/sign.c (do_sign, hash_for, sign_file): Ditto.
Be warned that this code is subject to further changes and that the
format will very likely change before a release. There are also known
bugs and missing code.
- Signed-off-by: Werner Koch <wk@gnupg.org>