Convert tls1_process_ticket to CBS.

ok miod@ jsing@

2 files changed, 38 insertions, 31 deletions

diff --git a/lib/libssl/ssl_locl.h b/lib/libssl/ssl_locl.h
index d05ef600e56..74b699a48c9 100644
--- a/lib/libssl/ssl_locl.h
+++ b/lib/libssl/ssl_locl.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_locl.h,v 1.99 2015/07/19 07:30:06 doug Exp $ */
+/* $OpenBSD: ssl_locl.h,v 1.100 2015/07/24 07:57:48 doug Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -825,9 +825,8 @@ int ssl_check_clienthello_tlsext_late(SSL *s);
 int ssl_check_serverhello_tlsext(SSL *s);
 
 #define tlsext_tick_md	EVP_sha256
-int tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
+int tls1_process_ticket(SSL *s, const unsigned char *session_id, int len,
     const unsigned char *limit, SSL_SESSION **ret);
-
 int tls12_get_sigandhash(unsigned char *p, const EVP_PKEY *pk,
     const EVP_MD *md);
 int tls12_get_sigid(const EVP_PKEY *pk);
diff --git a/lib/libssl/t1_lib.c b/lib/libssl/t1_lib.c
index 2481a71f841..9ee495c7908 100644
--- a/lib/libssl/t1_lib.c
+++ b/lib/libssl/t1_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: t1_lib.c,v 1.81 2015/07/24 03:50:12 doug Exp $ */
+/* $OpenBSD: t1_lib.c,v 1.82 2015/07/24 07:57:48 doug Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -2046,12 +2046,11 @@ ssl_check_serverhello_tlsext(SSL *s)
  *   Otherwise, s->tlsext_ticket_expected is set to 0.
  */
 int
-tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
+tls1_process_ticket(SSL *s, const unsigned char *session, int session_len,
     const unsigned char *limit, SSL_SESSION **ret)
 {
 	/* Point after session ID in client hello */
-	const unsigned char *p = session_id + len;
-	unsigned short i;
+	CBS session_id, cookie, cipher_list, compress_algo, extensions;
 
 	*ret = NULL;
 	s->tlsext_ticket_expected = 0;
@@ -2061,40 +2060,47 @@ tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
 	 */
 	if (SSL_get_options(s) & SSL_OP_NO_TICKET)
 		return 0;
-	if ((s->version <= SSL3_VERSION) || !limit)
+	if (s->version <= SSL3_VERSION || !limit)
 		return 0;
-	if (p >= limit)
+
+	if (limit < session)
 		return -1;
+
+	CBS_init(&session_id, session, limit - session);
+
+	/* Skip past the session id */
+	if (!CBS_skip(&session_id, session_len))
+		return -1;
+
 	/* Skip past DTLS cookie */
 	if (SSL_IS_DTLS(s)) {
-		i = *(p++);
-		p += i;
-		if (p >= limit)
+		if (!CBS_get_u8_length_prefixed(&session_id, &cookie))
 			return -1;
 	}
+
 	/* Skip past cipher list */
-	n2s(p, i);
-	p += i;
-	if (p >= limit)
+	if (!CBS_get_u16_length_prefixed(&session_id, &cipher_list))
 		return -1;
+
 	/* Skip past compression algorithm list */
-	i = *(p++);
-	p += i;
-	if (p > limit)
+	if (!CBS_get_u8_length_prefixed(&session_id, &compress_algo))
 		return -1;
+
 	/* Now at start of extensions */
-	if ((p + 2) >= limit)
-		return 0;
-	n2s(p, i);
-	while ((p + 4) <= limit) {
-		unsigned short type, size;
-		n2s(p, type);
-		n2s(p, size);
-		if (p + size > limit)
-			return 0;
-		if (type == TLSEXT_TYPE_session_ticket) {
+	if (!CBS_get_u16_length_prefixed(&session_id, &extensions))
+		return -1;
+
+	while (CBS_len(&extensions) > 0) {
+		CBS ext_data;
+		uint16_t ext_type;
+
+		if (!CBS_get_u16(&extensions, &ext_type) ||
+		    !CBS_get_u16_length_prefixed(&extensions, &ext_data))
+			return -1;
+
+		if (ext_type == TLSEXT_TYPE_session_ticket) {
 			int r;
-			if (size == 0) {
+			if (CBS_len(&ext_data) == 0) {
 				/* The client will accept a ticket but doesn't
 				 * currently have one. */
 				s->tlsext_ticket_expected = 1;
@@ -2108,7 +2114,10 @@ tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
 				 * calculate the master secret later. */
 				return 2;
 			}
-			r = tls_decrypt_ticket(s, p, size, session_id, len, ret);
+
+			r = tls_decrypt_ticket(s, CBS_data(&ext_data),
+			    CBS_len(&ext_data), session, session_len, ret);
+
 			switch (r) {
 			case 2: /* ticket couldn't be decrypted */
 				s->tlsext_ticket_expected = 1;
@@ -2122,7 +2131,6 @@ tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
 				return -1;
 			}
 		}
-		p += size;
 	}
 	return 0;
 }