Implement Elliptic Curve Cryptography modes for key exchange (ECDH) and

host/user keys (ECDSA) as specified by RFC5656. ECDH and ECDSA offer
better performance than plain DH and DSA at the same equivalent symmetric
key length, as well as much shorter keys.

Only the mandatory sections of RFC5656 are implemented, specifically the
three REQUIRED curves nistp256, nistp384 and nistp521 and only ECDH and
ECDSA. Point compression (optional in RFC5656 is NOT implemented).

Certificate host and user keys using the new ECDSA key types are supported.

Note that this code has not been tested for interoperability and may be
subject to change.

feedback and ok markus@

1 files changed, 31 insertions, 1 deletions

diff --git a/usr.bin/ssh/authfile.c b/usr.bin/ssh/authfile.c
index 90271c31860..5fc9bb0d934 100644
--- a/usr.bin/ssh/authfile.c
+++ b/usr.bin/ssh/authfile.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: authfile.c,v 1.82 2010/08/04 05:49:22 djm Exp $ */
+/* $OpenBSD: authfile.c,v 1.83 2010/08/31 11:54:45 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -204,6 +204,10 @@ key_save_private_pem(Key *key, const char *filename, const char *_passphrase,
 		success = PEM_write_DSAPrivateKey(fp, key->dsa,
 		    cipher, passphrase, len, NULL, NULL);
 		break;
+	case KEY_ECDSA:
+		success = PEM_write_ECPrivateKey(fp, key->ecdsa,
+		    cipher, passphrase, len, NULL, NULL);
+		break;
 	case KEY_RSA:
 		success = PEM_write_RSAPrivateKey(fp, key->rsa,
 		    cipher, passphrase, len, NULL, NULL);
@@ -222,6 +226,7 @@ key_save_private(Key *key, const char *filename, const char *passphrase,
 		return key_save_private_rsa1(key, filename, passphrase,
 		    comment);
 	case KEY_DSA:
+	case KEY_ECDSA:
 	case KEY_RSA:
 		return key_save_private_pem(key, filename, passphrase,
 		    comment);
@@ -501,6 +506,29 @@ key_load_private_pem(int fd, int type, const char *passphrase,
 #ifdef DEBUG_PK
 		DSA_print_fp(stderr, prv->dsa, 8);
 #endif
+	} else if (pk->type == EVP_PKEY_EC &&
+	    (type == KEY_UNSPEC||type==KEY_ECDSA)) {
+		prv = key_new(KEY_UNSPEC);
+		prv->ecdsa = EVP_PKEY_get1_EC_KEY(pk);
+		prv->type = KEY_ECDSA;
+		prv->ecdsa_nid = key_ecdsa_group_to_nid(
+		    EC_KEY_get0_group(prv->ecdsa));
+		if (key_curve_nid_to_name(prv->ecdsa_nid) == NULL) {
+			key_free(prv);
+			prv = NULL;
+		}
+		if (key_ec_validate_public(EC_KEY_get0_group(prv->ecdsa),
+		    EC_KEY_get0_public_key(prv->ecdsa)) != 0 ||
+		    key_ec_validate_private(prv->ecdsa) != 0) {
+			error("%s: bad ECDSA key", __func__);
+			key_free(prv);
+			prv = NULL;
+		}
+		name = "dsa w/o comment";
+#ifdef DEBUG_PK
+		if (prv->ecdsa != NULL)
+			key_dump_ec_key(prv->ecdsa);
+#endif
 	} else {
 		error("PEM_read_PrivateKey: mismatch or "
 		    "unknown EVP_PKEY save_type %d", pk->save_type);
@@ -569,6 +597,7 @@ key_load_private_type(int type, const char *filename, const char *passphrase,
 		    commentp);
 		/* closes fd */
 	case KEY_DSA:
+	case KEY_ECDSA:
 	case KEY_RSA:
 	case KEY_UNSPEC:
 		return key_load_private_pem(fd, type, passphrase, commentp);
@@ -709,6 +738,7 @@ key_load_private_cert(int type, const char *filename, const char *passphrase,
 	switch (type) {
 	case KEY_RSA:
 	case KEY_DSA:
+	case KEY_ECDSA:
 		break;
 	default:
 		error("%s: unsupported key type", __func__);