Convert ssl_parse_clienthello_renegotiate_ext to CBS.

ok miod@, tweak + ok jsing@

2 files changed, 14 insertions, 15 deletions

diff --git a/lib/libssl/ssl_locl.h b/lib/libssl/ssl_locl.h
index 794769b79cc..b55e8265afd 100644
--- a/lib/libssl/ssl_locl.h
+++ b/lib/libssl/ssl_locl.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_locl.h,v 1.91 2015/06/18 22:51:05 doug Exp $ */
+/* $OpenBSD: ssl_locl.h,v 1.92 2015/06/20 04:04:35 doug Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -839,7 +839,7 @@ int ssl_parse_serverhello_renegotiate_ext(SSL *s, unsigned char *d,
     int len, int *al);
 int ssl_add_clienthello_renegotiate_ext(SSL *s, unsigned char *p,
     int *len, int maxlen);
-int ssl_parse_clienthello_renegotiate_ext(SSL *s, unsigned char *d,
+int ssl_parse_clienthello_renegotiate_ext(SSL *s, const unsigned char *d,
     int len, int *al);
 long ssl_get_algorithm2(SSL *s);
 int tls1_process_sigalgs(SSL *s, const unsigned char *data, int dsize);
diff --git a/lib/libssl/t1_reneg.c b/lib/libssl/t1_reneg.c
index c93105ef4dd..52d1754d94b 100644
--- a/lib/libssl/t1_reneg.c
+++ b/lib/libssl/t1_reneg.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: t1_reneg.c,v 1.9 2014/11/16 14:12:47 jsing Exp $ */
+/* $OpenBSD: t1_reneg.c,v 1.10 2015/06/20 04:04:36 doug Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -114,6 +114,7 @@
 #include <openssl/objects.h>
 
 #include "ssl_locl.h"
+#include "bytestring.h"
 
 /* Add the client's renegotiation binding */
 int
@@ -144,23 +145,22 @@ ssl_add_clienthello_renegotiate_ext(SSL *s, unsigned char *p, int *len,
 /* Parse the client's renegotiation binding and abort if it's not
    right */
 int
-ssl_parse_clienthello_renegotiate_ext(SSL *s, unsigned char *d, int len,
+ssl_parse_clienthello_renegotiate_ext(SSL *s, const unsigned char *d, int len,
     int *al)
 {
-	int ilen;
+	CBS cbs, reneg;
 
-	/* Parse the length byte */
-	if (len < 1) {
+	if (len < 0) {
 		SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT,
 		    SSL_R_RENEGOTIATION_ENCODING_ERR);
 		*al = SSL_AD_ILLEGAL_PARAMETER;
 		return 0;
 	}
-	ilen = *d;
-	d++;
 
-	/* Consistency check */
-	if ((ilen + 1) != len) {
+	CBS_init(&cbs, d, len);
+	if (!CBS_get_u8_length_prefixed(&cbs, &reneg) ||
+	    /* Consistency check */
+	    CBS_len(&cbs) != 0) {
 		SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT,
 		    SSL_R_RENEGOTIATION_ENCODING_ERR);
 		*al = SSL_AD_ILLEGAL_PARAMETER;
@@ -168,22 +168,21 @@ ssl_parse_clienthello_renegotiate_ext(SSL *s, unsigned char *d, int len,
 	}
 
 	/* Check that the extension matches */
-	if (ilen != s->s3->previous_client_finished_len) {
+	if (CBS_len(&reneg) != s->s3->previous_client_finished_len) {
 		SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT,
 		    SSL_R_RENEGOTIATION_MISMATCH);
 		*al = SSL_AD_HANDSHAKE_FAILURE;
 		return 0;
 	}
 
-	if (timingsafe_memcmp(d, s->s3->previous_client_finished,
-	    s->s3->previous_client_finished_len) != 0) {
+	if (!CBS_mem_equal(&reneg, s->s3->previous_client_finished,
+	    s->s3->previous_client_finished_len)) {
 		SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT,
 		    SSL_R_RENEGOTIATION_MISMATCH);
 		*al = SSL_AD_HANDSHAKE_FAILURE;
 		return 0;
 	}
 
-
 	s->s3->send_connection_binding = 1;
 
 	return 1;