Convert ssl_bytes_to_cipher_list to CBS.

Link in the new 'unit' regress and expand the invalid tests to include
some that would fail before the CBS conversion.

input + ok miod@ jsing@

6 files changed, 59 insertions, 23 deletions

diff --git a/lib/libssl/src/ssl/ssl_lib.c b/lib/libssl/src/ssl/ssl_lib.c
index b5ce2ea5ace..1dd518d0b83 100644
--- a/lib/libssl/src/ssl/ssl_lib.c
+++ b/lib/libssl/src/ssl/ssl_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_lib.c,v 1.103 2015/04/15 16:25:43 jsing Exp $ */
+/* $OpenBSD: ssl_lib.c,v 1.104 2015/06/28 00:08:27 doug Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -155,6 +155,8 @@
 #include <openssl/engine.h>
 #endif
 
+#include "bytestring.h"
+
 const char *SSL_version_str = OPENSSL_VERSION_TEXT;
 
 SSL3_ENC_METHOD ssl3_undef_enc_method = {
@@ -1410,19 +1412,21 @@ ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk, unsigned char *p)
 }
 
 STACK_OF(SSL_CIPHER) *
-ssl_bytes_to_cipher_list(SSL *s, unsigned char *p, int num)
+ssl_bytes_to_cipher_list(SSL *s, const unsigned char *p, int num)
 {
+	CBS			 cbs;
 	const SSL_CIPHER	*c;
 	STACK_OF(SSL_CIPHER)	*sk = NULL;
-	int			 i;
 	unsigned long		 cipher_id;
-	uint16_t		 cipher_value;
-	uint16_t		 max_version;
+	uint16_t		 cipher_value, max_version;
 
 	if (s->s3)
 		s->s3->send_connection_binding = 0;
 
-	if ((num % SSL3_CIPHER_VALUE_SIZE) != 0) {
+	/*
+	 * RFC 5246 section 7.4.1.2 defines the interval as [2,2^16-2].
+	 */
+	if (num < 2 || num > 0x10000 - 2) {
 		SSLerr(SSL_F_SSL_BYTES_TO_CIPHER_LIST,
 		    SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST);
 		return (NULL);
@@ -1433,8 +1437,14 @@ ssl_bytes_to_cipher_list(SSL *s, unsigned char *p, int num)
 		goto err;
 	}
 
-	for (i = 0; i < num; i += SSL3_CIPHER_VALUE_SIZE) {
-		n2s(p, cipher_value);
+	CBS_init(&cbs, p, num);
+	while (CBS_len(&cbs) > 0) {
+		if (!CBS_get_u16(&cbs, &cipher_value)) {
+			SSLerr(SSL_F_SSL_BYTES_TO_CIPHER_LIST,
+			    SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST);
+			goto err;
+		}
+
 		cipher_id = SSL3_CK_ID | cipher_value;
 
 		if (s->s3 != NULL && cipher_id == SSL3_CK_SCSV) {
diff --git a/lib/libssl/src/ssl/ssl_locl.h b/lib/libssl/src/ssl/ssl_locl.h
index 43c6974268f..8116bfddfae 100644
--- a/lib/libssl/src/ssl/ssl_locl.h
+++ b/lib/libssl/src/ssl/ssl_locl.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_locl.h,v 1.93 2015/06/20 16:42:48 doug Exp $ */
+/* $OpenBSD: ssl_locl.h,v 1.94 2015/06/28 00:08:27 doug Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -569,7 +569,7 @@ int ssl_cipher_id_cmp(const SSL_CIPHER *a, const SSL_CIPHER *b);
 DECLARE_OBJ_BSEARCH_GLOBAL_CMP_FN(SSL_CIPHER, SSL_CIPHER, ssl_cipher_id);
 int ssl_cipher_ptr_id_cmp(const SSL_CIPHER * const *ap,
     const SSL_CIPHER * const *bp);
-STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *s, unsigned char *p,
+STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *s, const unsigned char *p,
     int num);
 int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk,
     unsigned char *p);
diff --git a/lib/libssl/ssl_lib.c b/lib/libssl/ssl_lib.c
index b5ce2ea5ace..1dd518d0b83 100644
--- a/lib/libssl/ssl_lib.c
+++ b/lib/libssl/ssl_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_lib.c,v 1.103 2015/04/15 16:25:43 jsing Exp $ */
+/* $OpenBSD: ssl_lib.c,v 1.104 2015/06/28 00:08:27 doug Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -155,6 +155,8 @@
 #include <openssl/engine.h>
 #endif
 
+#include "bytestring.h"
+
 const char *SSL_version_str = OPENSSL_VERSION_TEXT;
 
 SSL3_ENC_METHOD ssl3_undef_enc_method = {
@@ -1410,19 +1412,21 @@ ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk, unsigned char *p)
 }
 
 STACK_OF(SSL_CIPHER) *
-ssl_bytes_to_cipher_list(SSL *s, unsigned char *p, int num)
+ssl_bytes_to_cipher_list(SSL *s, const unsigned char *p, int num)
 {
+	CBS			 cbs;
 	const SSL_CIPHER	*c;
 	STACK_OF(SSL_CIPHER)	*sk = NULL;
-	int			 i;
 	unsigned long		 cipher_id;
-	uint16_t		 cipher_value;
-	uint16_t		 max_version;
+	uint16_t		 cipher_value, max_version;
 
 	if (s->s3)
 		s->s3->send_connection_binding = 0;
 
-	if ((num % SSL3_CIPHER_VALUE_SIZE) != 0) {
+	/*
+	 * RFC 5246 section 7.4.1.2 defines the interval as [2,2^16-2].
+	 */
+	if (num < 2 || num > 0x10000 - 2) {
 		SSLerr(SSL_F_SSL_BYTES_TO_CIPHER_LIST,
 		    SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST);
 		return (NULL);
@@ -1433,8 +1437,14 @@ ssl_bytes_to_cipher_list(SSL *s, unsigned char *p, int num)
 		goto err;
 	}
 
-	for (i = 0; i < num; i += SSL3_CIPHER_VALUE_SIZE) {
-		n2s(p, cipher_value);
+	CBS_init(&cbs, p, num);
+	while (CBS_len(&cbs) > 0) {
+		if (!CBS_get_u16(&cbs, &cipher_value)) {
+			SSLerr(SSL_F_SSL_BYTES_TO_CIPHER_LIST,
+			    SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST);
+			goto err;
+		}
+
 		cipher_id = SSL3_CK_ID | cipher_value;
 
 		if (s->s3 != NULL && cipher_id == SSL3_CK_SCSV) {
diff --git a/lib/libssl/ssl_locl.h b/lib/libssl/ssl_locl.h
index 43c6974268f..8116bfddfae 100644
--- a/lib/libssl/ssl_locl.h
+++ b/lib/libssl/ssl_locl.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_locl.h,v 1.93 2015/06/20 16:42:48 doug Exp $ */
+/* $OpenBSD: ssl_locl.h,v 1.94 2015/06/28 00:08:27 doug Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -569,7 +569,7 @@ int ssl_cipher_id_cmp(const SSL_CIPHER *a, const SSL_CIPHER *b);
 DECLARE_OBJ_BSEARCH_GLOBAL_CMP_FN(SSL_CIPHER, SSL_CIPHER, ssl_cipher_id);
 int ssl_cipher_ptr_id_cmp(const SSL_CIPHER * const *ap,
     const SSL_CIPHER * const *bp);
-STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *s, unsigned char *p,
+STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *s, const unsigned char *p,
     int num);
 int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk,
     unsigned char *p);
diff --git a/regress/lib/libssl/Makefile b/regress/lib/libssl/Makefile
index 4d64dc39660..7c2d92e3400 100644
--- a/regress/lib/libssl/Makefile
+++ b/regress/lib/libssl/Makefile
@@ -1,10 +1,11 @@
-#	$OpenBSD: Makefile,v 1.21 2015/02/06 09:36:16 doug Exp $
+#	$OpenBSD: Makefile,v 1.22 2015/06/28 00:08:27 doug Exp $
 
 SUBDIR= \
 	asn1 \
 	bytestring \
 	ciphers \
-	ssl
+	ssl \
+	unit
 
 install:
 
diff --git a/regress/lib/libssl/unit/cipher_list.c b/regress/lib/libssl/unit/cipher_list.c
index b5130077710..1c829f369c3 100644
--- a/regress/lib/libssl/unit/cipher_list.c
+++ b/regress/lib/libssl/unit/cipher_list.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cipher_list.c,v 1.1 2015/06/27 23:35:52 doug Exp $	*/
+/*	$OpenBSD: cipher_list.c,v 1.2 2015/06/28 00:08:27 doug Exp $	*/
 /*
  * Copyright (c) 2015 Doug Hogan <doug@openbsd.org>
  * Copyright (c) 2015 Joel Sing <jsing@openbsd.org>
@@ -146,6 +146,8 @@ err:
 static int
 ssl_bytes_to_list_invalid(SSL *s, STACK_OF(SSL_CIPHER) **ciphers)
 {
+	uint8_t empty_cipher_bytes[] = { };
+
 	sk_SSL_CIPHER_free(*ciphers);
 
 	/* Invalid length: CipherSuite is 2 bytes so it must be even */
@@ -153,6 +155,19 @@ ssl_bytes_to_list_invalid(SSL *s, STACK_OF(SSL_CIPHER) **ciphers)
 	    sizeof(cipher_bytes) - 1);
 	CHECK(*ciphers == NULL);
 
+	/* Invalid length: cipher_suites must be at least 2 */
+	*ciphers = ssl_bytes_to_cipher_list(s, empty_cipher_bytes,
+	    sizeof(empty_cipher_bytes));
+	CHECK(*ciphers == NULL);
+
+	/* Invalid length: cipher_suites must be at most 2^16-2 */
+	*ciphers = ssl_bytes_to_cipher_list(s, cipher_bytes, 0x10000);
+	CHECK(*ciphers == NULL);
+
+	/* Invalid len: prototype is signed, but it shouldn't accept len < 0 */
+	*ciphers = ssl_bytes_to_cipher_list(s, cipher_bytes, -2);
+	CHECK(*ciphers == NULL);
+
 	return 1;
 }