From: Ben Laurie <ben@links.org>
Date: Wed, 23 Apr 2014 17:13:20 +0000 (+0100)
Subject: Fix possible buffer overrun.
X-Git-Tag: OpenSSL_1_0_1i~63
X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff_plain;h=2db3ea29298bdc347f15fbfab6d5746022f05101

Fix possible buffer overrun.
---

diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h
index eb4d8f2fa9..97cde4055d 100644
--- a/ssl/ssl_locl.h
+++ b/ssl/ssl_locl.h
@@ -1096,8 +1096,8 @@ int tls1_ec_nid2curve_id(int nid);
 #endif /* OPENSSL_NO_EC */
 
 #ifndef OPENSSL_NO_TLSEXT
-unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned char *limit); 
-unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned char *limit); 
+unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit); 
+unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit); 
 int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **data, unsigned char *d, int n, int *al);
 int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **data, unsigned char *d, int n, int *al);
 int ssl_prepare_clienthello_tlsext(SSL *s);
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index f7abce9258..f6a480d0e2 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -352,15 +352,16 @@ int tls12_get_req_sig_algs(SSL *s, unsigned char *p)
 	return (int)slen;
 	}
 
-unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
+unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit)
 	{
 	int extdatalen=0;
-	unsigned char *ret = p;
+	unsigned char *orig = buf;
+	unsigned char *ret = buf;
 
 	/* don't add extensions for SSLv3 unless doing secure renegotiation */
 	if (s->client_version == SSL3_VERSION
 					&& !s->s3->send_connection_binding)
-		return p;
+		return orig;
 
 	ret+=2;
 
@@ -409,7 +410,7 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned cha
               return NULL;
               }
 
-          if((limit - p - 4 - el) < 0) return NULL;
+          if((limit - ret - 4 - el) < 0) return NULL;
           
           s2n(TLSEXT_TYPE_renegotiate,ret);
           s2n(el,ret);
@@ -650,7 +651,7 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned cha
 
                 ssl_add_clienthello_use_srtp_ext(s, 0, &el, 0);
                 
-                if((limit - p - 4 - el) < 0) return NULL;
+                if((limit - ret - 4 - el) < 0) return NULL;
 
                 s2n(TLSEXT_TYPE_use_srtp,ret);
                 s2n(el,ret);
@@ -693,24 +694,25 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned cha
 			}
 		}
 
-	if ((extdatalen = ret-p-2)== 0) 
-		return p;
+	if ((extdatalen = ret-orig-2)== 0) 
+		return orig;
 
-	s2n(extdatalen,p);
+	s2n(extdatalen, orig);
 	return ret;
 	}
 
-unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
+unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit)
 	{
 	int extdatalen=0;
-	unsigned char *ret = p;
+	unsigned char *orig = buf;
+	unsigned char *ret = buf;
 #ifndef OPENSSL_NO_NEXTPROTONEG
 	int next_proto_neg_seen;
 #endif
 
 	/* don't add extensions for SSLv3, unless doing secure renegotiation */
 	if (s->version == SSL3_VERSION && !s->s3->send_connection_binding)
-		return p;
+		return orig;
 	
 	ret+=2;
 	if (ret>=limit) return NULL; /* this really never occurs, but ... */
@@ -733,7 +735,7 @@ unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned cha
               return NULL;
               }
 
-          if((limit - p - 4 - el) < 0) return NULL;
+          if((limit - ret - 4 - el) < 0) return NULL;
           
           s2n(TLSEXT_TYPE_renegotiate,ret);
           s2n(el,ret);
@@ -813,7 +815,7 @@ unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned cha
 
                 ssl_add_serverhello_use_srtp_ext(s, 0, &el, 0);
                 
-                if((limit - p - 4 - el) < 0) return NULL;
+                if((limit - ret - 4 - el) < 0) return NULL;
 
                 s2n(TLSEXT_TYPE_use_srtp,ret);
                 s2n(el,ret);
@@ -884,10 +886,10 @@ unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned cha
 		}
 #endif
 
-	if ((extdatalen = ret-p-2)== 0) 
-		return p;
+	if ((extdatalen = ret-orig-2)== 0) 
+		return orig;
 
-	s2n(extdatalen,p);
+	s2n(extdatalen, orig);
 	return ret;
 	}