ecc: Support use of Ed25519 with ECDSA.

* src/cipher.h (PUBKEY_FLAG_ECDSA): New.
* cipher/pubkey-util.c (_gcry_pk_util_parse_flaglist): Add flag "ecdsa".
* cipher/ecc.c (verify_ecdsa, verify_eddsa): Remove some debug output.
(ecc_generate, ecc_sign, ecc_verify): Support Ed25519 with ECDSA.
* tests/keygen.c (check_ecc_keys): Create such a test key.
* tests/pubkey.c (fail, info, data_from_hex, extract_cmp_data): New.
Take from dsa-6979.c
(check_ed25519ecdsa_sample_key): new.
(main): Call new test.

Signed-off-by: Werner Koch <wk@gnupg.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/tests/keygen.c b/tests/keygen.c
index b955116c..2b98c42d 100644
--- a/tests/keygen.c
+++ b/tests/keygen.c
@@ -394,6 +394,23 @@ check_ecc_keys (void)
 
       gcry_sexp_release (key);
     }
+
+  if (verbose)
+    show ("creating ECC key using curve Ed25519 for ECDSA\n");
+  rc = gcry_sexp_build (&keyparm, NULL,
+                        "(genkey(ecc(curve Ed25519)(flags ecdsa)))");
+  if (rc)
+    die ("error creating S-expression: %s\n", gpg_strerror (rc));
+  rc = gcry_pk_genkey (&key, keyparm);
+  gcry_sexp_release (keyparm);
+  if (rc)
+    die ("error generating ECC key using curve Ed25519 for ECDSA: %s\n",
+         gpg_strerror (rc));
+
+  if (verbose > 1)
+    show_sexp ("ECC key:\n", key);
+
+  gcry_sexp_release (key);
 }