Pull out the code that identifies if we have an ECC cipher in the cipher

list or if we are negotiating an ECC cipher in the handshake. This dedups
some of the existing code and will make the EC extension rewrites easier.

ok doug@

3 files changed, 52 insertions, 34 deletions

diff --git a/lib/libssl/ssl_lib.c b/lib/libssl/ssl_lib.c
index c593e7b42bc..d933acb32d1 100644
--- a/lib/libssl/ssl_lib.c
+++ b/lib/libssl/ssl_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_lib.c,v 1.161 2017/05/07 04:22:24 beck Exp $ */
+/* $OpenBSD: ssl_lib.c,v 1.162 2017/08/09 22:24:25 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1259,6 +1259,33 @@ ssl_get_ciphers_by_id(SSL *s)
 	return (NULL);
 }
 
+/* See if we have any ECC cipher suites. */
+int
+ssl_has_ecc_ciphers(SSL *s)
+{
+	STACK_OF(SSL_CIPHER) *ciphers;
+	unsigned long alg_k, alg_a;
+	SSL_CIPHER *cipher;
+	int i;
+
+	if (s->version == DTLS1_VERSION)
+		return 0;
+	if ((ciphers = SSL_get_ciphers(s)) == NULL)
+		return 0;
+
+	for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) {
+		cipher = sk_SSL_CIPHER_value(ciphers, i);
+
+		alg_k = cipher->algorithm_mkey;
+		alg_a = cipher->algorithm_auth;
+
+		if ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))
+			return 1;
+	}
+
+	return 0;
+}
+
 /* The old interface to get the same thing as SSL_get_ciphers(). */
 const char *
 SSL_get_cipher_list(const SSL *s, int n)
@@ -2085,6 +2112,20 @@ ssl_set_cert_masks(CERT *c, const SSL_CIPHER *cipher)
 	c->valid = 1;
 }
 
+/* See if this handshake is using an ECC cipher suite. */
+int
+ssl_using_ecc_cipher(SSL *s)
+{
+	unsigned long alg_a, alg_k;
+
+	alg_a = S3I(s)->hs.new_cipher->algorithm_auth;
+	alg_k = S3I(s)->hs.new_cipher->algorithm_mkey;
+
+	return SSI(s)->tlsext_ecpointformatlist != NULL &&
+	    SSI(s)->tlsext_ecpointformatlist_length > 0 &&
+	    ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA));
+}
+
 int
 ssl_check_srvr_ecc_cert_and_alg(X509 *x, SSL *s)
 {
diff --git a/lib/libssl/ssl_locl.h b/lib/libssl/ssl_locl.h
index 0d489204710..f98ce681a24 100644
--- a/lib/libssl/ssl_locl.h
+++ b/lib/libssl/ssl_locl.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_locl.h,v 1.182 2017/07/24 17:10:31 jsing Exp $ */
+/* $OpenBSD: ssl_locl.h,v 1.183 2017/08/09 22:24:25 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1127,6 +1127,7 @@ DH *ssl_get_auto_dh(SSL *s);
 int ssl_cert_type(X509 *x, EVP_PKEY *pkey);
 void ssl_set_cert_masks(CERT *c, const SSL_CIPHER *cipher);
 STACK_OF(SSL_CIPHER) *ssl_get_ciphers_by_id(SSL *s);
+int ssl_has_ecc_ciphers(SSL *s);
 int ssl_verify_alarm_type(long type);
 void ssl_load_ciphers(void);
 
@@ -1312,6 +1313,7 @@ int tls1_export_keying_material(SSL *s, unsigned char *out, size_t olen,
 int tls1_alert_code(int code);
 int ssl_ok(SSL *s);
 
+int ssl_using_ecc_cipher(SSL *s);
 int ssl_check_srvr_ecc_cert_and_alg(X509 *x, SSL *s);
 
 int tls1_set_groups(uint16_t **out_group_ids, size_t *out_group_ids_len,
diff --git a/lib/libssl/t1_lib.c b/lib/libssl/t1_lib.c
index b061bd11006..ea44e7579a8 100644
--- a/lib/libssl/t1_lib.c
+++ b/lib/libssl/t1_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: t1_lib.c,v 1.122 2017/07/24 17:39:43 jsing Exp $ */
+/* $OpenBSD: t1_lib.c,v 1.123 2017/08/09 22:24:25 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -679,28 +679,11 @@ ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
 {
 	int extdatalen = 0;
 	unsigned char *ret = p;
-	int using_ecc = 0;
+	int using_ecc;
 	size_t len;
 	CBB cbb;
 
-	/* See if we support any ECC ciphersuites. */
-	if (s->version != DTLS1_VERSION && s->version >= TLS1_VERSION) {
-		STACK_OF(SSL_CIPHER) *cipher_stack = SSL_get_ciphers(s);
-		unsigned long alg_k, alg_a;
-		int i;
-
-		for (i = 0; i < sk_SSL_CIPHER_num(cipher_stack); i++) {
-			SSL_CIPHER *c = sk_SSL_CIPHER_value(cipher_stack, i);
-
-			alg_k = c->algorithm_mkey;
-			alg_a = c->algorithm_auth;
-
-			if ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA)) {
-				using_ecc = 1;
-				break;
-			}
-		}
-	}
+	using_ecc = ssl_has_ecc_ciphers(s);
 
 	ret += 2;
 	if (ret >= limit)
@@ -954,16 +937,12 @@ unsigned char *
 ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
 {
 	int using_ecc, extdatalen = 0;
-	unsigned long alg_a, alg_k;
 	unsigned char *ret = p;
 	int next_proto_neg_seen;
 	size_t len;
 	CBB cbb;
 
-	alg_a = S3I(s)->hs.new_cipher->algorithm_auth;
-	alg_k = S3I(s)->hs.new_cipher->algorithm_mkey;
-	using_ecc = ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA)) &&
-	    SSI(s)->tlsext_ecpointformatlist != NULL;
+	using_ecc = ssl_using_ecc_cipher(s);
 
 	ret += 2;
 	if (ret >= limit)
@@ -1809,13 +1788,9 @@ ssl_check_serverhello_tlsext(SSL *s)
 	 * suite, then if server returns an EC point formats lists extension
 	 * it must contain uncompressed.
 	 */
-	unsigned long alg_k = S3I(s)->hs.new_cipher->algorithm_mkey;
-	unsigned long alg_a = S3I(s)->hs.new_cipher->algorithm_auth;
-	if ((s->internal->tlsext_ecpointformatlist != NULL) &&
-	    (s->internal->tlsext_ecpointformatlist_length > 0) &&
-	    (SSI(s)->tlsext_ecpointformatlist != NULL) &&
-	    (SSI(s)->tlsext_ecpointformatlist_length > 0) &&
-	    ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
+	if (ssl_using_ecc_cipher(s) &&
+	    s->internal->tlsext_ecpointformatlist != NULL &&
+	    s->internal->tlsext_ecpointformatlist_length > 0) {
 		/* we are using an ECC cipher */
 		size_t i;
 		unsigned char *list;