Convert ssl_parse_clienthello_use_srtp_ext to CBS.

ok miod@ jsing@

1 files changed, 23 insertions, 40 deletions

diff --git a/src/lib/libssl/d1_srtp.c b/src/lib/libssl/d1_srtp.c
index 7c426f1145..801eab1b76 100644
--- a/src/lib/libssl/d1_srtp.c
+++ b/src/lib/libssl/d1_srtp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: d1_srtp.c,v 1.11 2014/12/14 15:30:50 jsing Exp $ */
+/* $OpenBSD: d1_srtp.c,v 1.12 2015/07/14 03:38:26 doug Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -123,9 +123,9 @@
 
 #ifndef OPENSSL_NO_SRTP
 
+#include "bytestring.h"
 #include "srtp.h"
 
-
 static SRTP_PROTECTION_PROFILE srtp_known_profiles[] = {
         {
                 "SRTP_AES128_CM_SHA1_80",
@@ -293,65 +293,48 @@ ssl_add_clienthello_use_srtp_ext(SSL *s, unsigned char *p, int *len, int maxlen)
 
 
 int
-ssl_parse_clienthello_use_srtp_ext(SSL *s, unsigned char *d, int len, int *al)
+ssl_parse_clienthello_use_srtp_ext(SSL *s, const unsigned char *d, int len,
+    int *al)
 {
         SRTP_PROTECTION_PROFILE *cprof, *sprof;
         STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = 0, *srvr;
-        int ct;
-        int mki_len;
         int i, j;
-        int id;
         int ret = 1;
+        uint16_t id;
+        CBS cbs, ciphers, mki;
 
-        /* Length value + the MKI length */
-        if (len < 3) {
-                SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
-                    SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
-                *al = SSL_AD_DECODE_ERROR;
-                goto done;
-        }
-
-        /* Pull off the length of the cipher suite list */
-        n2s(d, ct);
-        len -= 2;
-
-        /* Check that it is even */
-        if (ct % 2) {
-                SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
-                    SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
-                *al = SSL_AD_DECODE_ERROR;
-                goto done;
-        }
+        CBS_init(&cbs, d, len);
 
-        /* Check that lengths are consistent */
-        if (len < (ct + 1)) {
+        /* Pull off the cipher suite list */
+        if (len < 0 ||
+            !CBS_get_u16_length_prefixed(&cbs, &ciphers) ||
+            CBS_len(&ciphers) % 2 ||
+            CBS_len(&cbs) != 0) {
                 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
                     SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
                 *al = SSL_AD_DECODE_ERROR;
                 goto done;
         }
 
-
         clnt = sk_SRTP_PROTECTION_PROFILE_new_null();
 
-        while (ct) {
-                n2s(d, id);
-                ct -= 2;
-                len -= 2;
+        while (CBS_len(&ciphers) > 0) {
+                if (!CBS_get_u16(&ciphers, &id)) {
+                        SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
+                            SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
+                        *al = SSL_AD_DECODE_ERROR;
+                        goto done;
+                }
 
-                if (!find_profile_by_num(id, &cprof)) {
+                if (!find_profile_by_num(id, &cprof))
                         sk_SRTP_PROTECTION_PROFILE_push(clnt, cprof);
-                } else {
+                else
                         ; /* Ignore */
-                }
         }
 
         /* Extract the MKI value as a sanity check, but discard it for now. */
-        mki_len = *d;
-        d++;
-        len--;
-
-        if (mki_len != len) {
+        if (!CBS_get_u8_length_prefixed(&cbs, &mki) ||
+            CBS_len(&cbs) != 0) {
                 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
                     SSL_R_BAD_SRTP_MKI_VALUE);
                 *al = SSL_AD_DECODE_ERROR;