Advertise support of only the NIST curves P-521, P-384, and P-256 to

openssl/ssl/t1_lib.c

Index: openssl/ssl/t1_lib.c
===================================================================
--- openssl/ssl/t1_lib.c	(revision 207924)
+++ openssl/ssl/t1_lib.c	(working copy)
@@ -202,33 +202,14 @@
 		NID_secp521r1  /* secp521r1 (25) */	
 	};
 
+/* We support only the elliptic curves that are also supported by NSS
+ * to improve compatibility with sites that don't accept large ClientHellos.
+ */
 static int pref_list[] =
 	{
-		NID_sect571r1, /* sect571r1 (14) */ 
-		NID_sect571k1, /* sect571k1 (13) */ 
 		NID_secp521r1, /* secp521r1 (25) */	
-		NID_sect409k1, /* sect409k1 (11) */ 
-		NID_sect409r1, /* sect409r1 (12) */
 		NID_secp384r1, /* secp384r1 (24) */
-		NID_sect283k1, /* sect283k1 (9) */
-		NID_sect283r1, /* sect283r1 (10) */ 
-		NID_secp256k1, /* secp256k1 (22) */ 
 		NID_X9_62_prime256v1, /* secp256r1 (23) */ 
-		NID_sect239k1, /* sect239k1 (8) */ 
-		NID_sect233k1, /* sect233k1 (6) */
-		NID_sect233r1, /* sect233r1 (7) */ 
-		NID_secp224k1, /* secp224k1 (20) */ 
-		NID_secp224r1, /* secp224r1 (21) */
-		NID_sect193r1, /* sect193r1 (4) */ 
-		NID_sect193r2, /* sect193r2 (5) */ 
-		NID_secp192k1, /* secp192k1 (18) */
-		NID_X9_62_prime192v1, /* secp192r1 (19) */ 
-		NID_sect163k1, /* sect163k1 (1) */
-		NID_sect163r1, /* sect163r1 (2) */
-		NID_sect163r2, /* sect163r2 (3) */
-		NID_secp160k1, /* secp160k1 (15) */
-		NID_secp160r1, /* secp160r1 (16) */ 
-		NID_secp160r2, /* secp160r2 (17) */ 
 	};
 
 int tls1_ec_curve_id2nid(int curve_id)
@@ -1703,17 +1684,18 @@
 	if (using_ecc)
 		{
 		if (s->tlsext_ecpointformatlist != NULL) OPENSSL_free(s->tlsext_ecpointformatlist);
-		if ((s->tlsext_ecpointformatlist = OPENSSL_malloc(3)) == NULL)
+		/* To save an additional 2 bytes in the ClientHello, we only advertise support
+		 * for the only EC Point Format that NSS supports (instead of all 3).
+		 */
+		if ((s->tlsext_ecpointformatlist = OPENSSL_malloc(1)) == NULL)
 			{
 			SSLerr(SSL_F_SSL_PREPARE_CLIENTHELLO_TLSEXT,ERR_R_MALLOC_FAILURE);
 			return -1;
 			}
-		s->tlsext_ecpointformatlist_length = 3;
+		s->tlsext_ecpointformatlist_length = 1;
 		s->tlsext_ecpointformatlist[0] = TLSEXT_ECPOINTFORMAT_uncompressed;
-		s->tlsext_ecpointformatlist[1] = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
-		s->tlsext_ecpointformatlist[2] = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
 
-		/* we support all named elliptic curves in draft-ietf-tls-ecc-12 */
+		/* we only advertise support for elliptic curves in NSA Suite B */
 		if (s->tlsext_ellipticcurvelist != NULL) OPENSSL_free(s->tlsext_ellipticcurvelist);
 		s->tlsext_ellipticcurvelist_length = sizeof(pref_list)/sizeof(pref_list[0]) * 2;
 		if ((s->tlsext_ellipticcurvelist = OPENSSL_malloc(s->tlsext_ellipticcurvelist_length)) == NULL)