Tidy up OpenSSL padding extension code.

Add (redundant because of SSL3_RT_MAX_PLAIN_LENGTH) length check,
don't pad DTLS, and move the SSL23 special case closer to the SSL23
code.

BUG=none

Review URL: https://codereview.chromium.org/242453005

git-svn-id: http://src.chromium.org/svn/trunk/deps/third_party/openssl@267663 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

7 files changed, 172 insertions, 27 deletions

diff --git a/README.chromium b/README.chromium
index dcc03de..30df8b5 100644
--- a/README.chromium
+++ b/README.chromium
@@ -192,6 +192,10 @@ located in patches.chromium/. Currently this consists of:
   chacha.patch
     Add support for ChaCha20+Poly1305 cipher suites.
 
+  paddingext.patch
+  paddingext2.patch
+    Add ClientHello padding to workaround bug in F5 terminators.
+
   stricter_cutthrough.patch
     Requires NPN and a PFS cipher suite to enable cut-through (false start) on
     the client.
diff --git a/openssl/ssl/d1_clnt.c b/openssl/ssl/d1_clnt.c
index 7e8077e..735e544 100644
--- a/openssl/ssl/d1_clnt.c
+++ b/openssl/ssl/d1_clnt.c
@@ -874,7 +874,7 @@ int dtls1_client_hello(SSL *s)
 		*(p++)=0; /* Add the NULL method */
 
 #ifndef OPENSSL_NO_TLSEXT
-		if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH)) == NULL)
+		if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH, 0)) == NULL)
 			{
 			SSLerr(SSL_F_DTLS1_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
 			goto err;
diff --git a/openssl/ssl/s23_clnt.c b/openssl/ssl/s23_clnt.c
index 08ee86d..750d208 100644
--- a/openssl/ssl/s23_clnt.c
+++ b/openssl/ssl/s23_clnt.c
@@ -467,9 +467,9 @@ static int ssl23_client_hello(SSL *s)
 			/* create Client Hello in SSL 3.0/TLS 1.0 format */
 
 			/* do the record header (5 bytes) and handshake message
-			 * header (4 bytes) last. Note: the code to add the
-			 * padding extension in t1_lib.c depends on the size of
-			 * this prefix. */
+			 * header (4 bytes) last. Note: the final argument to
+			 * ssl_add_clienthello_tlsext below depends on the size
+			 * of this prefix. */
 			d = p = &(buf[9]);
 			
 			*(p++) = version_major;
@@ -526,7 +526,10 @@ static int ssl23_client_hello(SSL *s)
 				SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_CLIENTHELLO_TLSEXT);
 				return -1;
 				}
-			if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH)) == NULL)
+			/* The buffer includes the 5 byte record header, so
+			 * subtract it to compute hlen for
+			 * ssl_add_clienthello_tlsext. */
+			if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH, p-buf-5)) == NULL)
 				{
 				SSLerr(SSL_F_SSL23_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
 				return -1;
diff --git a/openssl/ssl/s3_clnt.c b/openssl/ssl/s3_clnt.c
index d1b3224..640df80 100644
--- a/openssl/ssl/s3_clnt.c
+++ b/openssl/ssl/s3_clnt.c
@@ -759,7 +759,7 @@ int ssl3_client_hello(SSL *s)
 			goto err;
 
 		/* Do the message type and length last.
-		 * Note: the code to add the padding extension in t1_lib.c
+		 * Note: the final argument to ssl_add_clienthello_tlsext below
 		 * depends on the size of this prefix. */
 		d=p= &(buf[4]);
 
@@ -867,7 +867,7 @@ int ssl3_client_hello(SSL *s)
 			SSLerr(SSL_F_SSL3_CLIENT_HELLO,SSL_R_CLIENTHELLO_TLSEXT);
 			goto err;
 			}
-		if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH)) == NULL)
+		if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH, p-buf)) == NULL)
 			{
 			SSLerr(SSL_F_SSL3_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
 			goto err;
diff --git a/openssl/ssl/ssl_locl.h b/openssl/ssl/ssl_locl.h
index 4e27d9e..531a291 100644
--- a/openssl/ssl/ssl_locl.h
+++ b/openssl/ssl/ssl_locl.h
@@ -1127,7 +1127,7 @@ 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 *buf, unsigned char *limit); 
+unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit, size_t header_len);
 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);
diff --git a/openssl/ssl/t1_lib.c b/openssl/ssl/t1_lib.c
index a53d56b..3fe6612 100644
--- a/openssl/ssl/t1_lib.c
+++ b/openssl/ssl/t1_lib.c
@@ -341,7 +341,10 @@ int tls12_get_req_sig_algs(SSL *s, unsigned char *p)
 	return (int)slen;
 	}
 
-unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit)
+/* header_len is the length of the ClientHello header written so far, used to
+ * compute padding. It does not include the record header. Pass 0 if no padding
+ * is to be done. */
+unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit, size_t header_len)
 	{
 	int extdatalen=0;
 	unsigned char *orig = buf;
@@ -664,27 +667,25 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned c
 
 	/* Add padding to workaround bugs in F5 terminators.
 	 * See https://tools.ietf.org/html/draft-agl-tls-padding-02 */
-	{
-	int hlen = ret - (unsigned char *)s->init_buf->data;
-	/* The code in s23_clnt.c to build ClientHello messages includes the
-	 * 5-byte record header in the buffer, while the code in s3_clnt.c does
-	 * not. */
-	if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
-		hlen -= 5;
-	if (hlen > 0xff && hlen < 0x200)
+	if (header_len > 0)
 		{
-		hlen = 0x200 - hlen;
-		if (hlen >= 4)
-			hlen -= 4;
-		else
-			hlen = 0;
+		header_len += ret - orig;
+		if (header_len > 0xff && header_len < 0x200)
+			{
+			size_t padding_len = 0x200 - header_len;
+			if (padding_len >= 4)
+				padding_len -= 4;
+			else
+				padding_len = 0;
+			if (limit - ret - 4 - (long)padding_len < 0)
+				return NULL;
 
-		s2n(TLSEXT_TYPE_padding, ret);
-		s2n(hlen, ret);
-		memset(ret, 0, hlen);
-		ret += hlen;
+			s2n(TLSEXT_TYPE_padding, ret);
+			s2n(padding_len, ret);
+			memset(ret, 0, padding_len);
+			ret += padding_len;
+			}
 		}
-	}
 
 
 	if ((extdatalen = ret-orig-2)== 0) 
diff --git a/patches.chromium/0012-paddingext2.patch b/patches.chromium/0012-paddingext2.patch
new file mode 100644
index 0000000..cb7652a
--- /dev/null
+++ b/patches.chromium/0012-paddingext2.patch
@@ -0,0 +1,137 @@
+diff --git android-openssl.orig/ssl/d1_clnt.c android-openssl/ssl/d1_clnt.c
+index 7e8077e..735e544 100644
+--- android-openssl.orig/ssl/d1_clnt.c
++++ android-openssl/ssl/d1_clnt.c
+@@ -874,7 +874,7 @@ int dtls1_client_hello(SSL *s)
+ 		*(p++)=0; /* Add the NULL method */
+ 
+ #ifndef OPENSSL_NO_TLSEXT
+-		if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH)) == NULL)
++		if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH, 0)) == NULL)
+ 			{
+ 			SSLerr(SSL_F_DTLS1_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
+ 			goto err;
+diff --git android-openssl.orig/ssl/s23_clnt.c android-openssl/ssl/s23_clnt.c
+index 08ee86d..750d208 100644
+--- android-openssl.orig/ssl/s23_clnt.c
++++ android-openssl/ssl/s23_clnt.c
+@@ -467,9 +467,9 @@ static int ssl23_client_hello(SSL *s)
+ 			/* create Client Hello in SSL 3.0/TLS 1.0 format */
+ 
+ 			/* do the record header (5 bytes) and handshake message
+-			 * header (4 bytes) last. Note: the code to add the
+-			 * padding extension in t1_lib.c depends on the size of
+-			 * this prefix. */
++			 * header (4 bytes) last. Note: the final argument to
++			 * ssl_add_clienthello_tlsext below depends on the size
++			 * of this prefix. */
+ 			d = p = &(buf[9]);
+ 			
+ 			*(p++) = version_major;
+@@ -526,7 +526,10 @@ static int ssl23_client_hello(SSL *s)
+ 				SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_CLIENTHELLO_TLSEXT);
+ 				return -1;
+ 				}
+-			if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH)) == NULL)
++			/* The buffer includes the 5 byte record header, so
++			 * subtract it to compute hlen for
++			 * ssl_add_clienthello_tlsext. */
++			if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH, p-buf-5)) == NULL)
+ 				{
+ 				SSLerr(SSL_F_SSL23_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
+ 				return -1;
+diff --git android-openssl.orig/ssl/s3_clnt.c android-openssl/ssl/s3_clnt.c
+index d1b3224..640df80 100644
+--- android-openssl.orig/ssl/s3_clnt.c
++++ android-openssl/ssl/s3_clnt.c
+@@ -759,7 +759,7 @@ int ssl3_client_hello(SSL *s)
+ 			goto err;
+ 
+ 		/* Do the message type and length last.
+-		 * Note: the code to add the padding extension in t1_lib.c
++		 * Note: the final argument to ssl_add_clienthello_tlsext below
+ 		 * depends on the size of this prefix. */
+ 		d=p= &(buf[4]);
+ 
+@@ -867,7 +867,7 @@ int ssl3_client_hello(SSL *s)
+ 			SSLerr(SSL_F_SSL3_CLIENT_HELLO,SSL_R_CLIENTHELLO_TLSEXT);
+ 			goto err;
+ 			}
+-		if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH)) == NULL)
++		if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH, p-buf)) == NULL)
+ 			{
+ 			SSLerr(SSL_F_SSL3_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
+ 			goto err;
+diff --git android-openssl.orig/ssl/ssl_locl.h android-openssl/ssl/ssl_locl.h
+index 4e27d9e..531a291 100644
+--- android-openssl.orig/ssl/ssl_locl.h
++++ android-openssl/ssl/ssl_locl.h
+@@ -1127,7 +1127,7 @@ 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 *buf, unsigned char *limit); 
++unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit, size_t header_len);
+ 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);
+diff --git android-openssl.orig/ssl/t1_lib.c android-openssl/ssl/t1_lib.c
+index a53d56b..3fe6612 100644
+--- android-openssl.orig/ssl/t1_lib.c
++++ android-openssl/ssl/t1_lib.c
+@@ -341,7 +341,10 @@ int tls12_get_req_sig_algs(SSL *s, unsigned char *p)
+ 	return (int)slen;
+ 	}
+ 
+-unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit)
++/* header_len is the length of the ClientHello header written so far, used to
++ * compute padding. It does not include the record header. Pass 0 if no padding
++ * is to be done. */
++unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit, size_t header_len)
+ 	{
+ 	int extdatalen=0;
+ 	unsigned char *orig = buf;
+@@ -664,27 +667,25 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned c
+ 
+ 	/* Add padding to workaround bugs in F5 terminators.
+ 	 * See https://tools.ietf.org/html/draft-agl-tls-padding-02 */
+-	{
+-	int hlen = ret - (unsigned char *)s->init_buf->data;
+-	/* The code in s23_clnt.c to build ClientHello messages includes the
+-	 * 5-byte record header in the buffer, while the code in s3_clnt.c does
+-	 * not. */
+-	if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
+-		hlen -= 5;
+-	if (hlen > 0xff && hlen < 0x200)
++	if (header_len > 0)
+ 		{
+-		hlen = 0x200 - hlen;
+-		if (hlen >= 4)
+-			hlen -= 4;
+-		else
+-			hlen = 0;
++		header_len += ret - orig;
++		if (header_len > 0xff && header_len < 0x200)
++			{
++			size_t padding_len = 0x200 - header_len;
++			if (padding_len >= 4)
++				padding_len -= 4;
++			else
++				padding_len = 0;
++			if (limit - ret - 4 - (long)padding_len < 0)
++				return NULL;
+ 
+-		s2n(TLSEXT_TYPE_padding, ret);
+-		s2n(hlen, ret);
+-		memset(ret, 0, hlen);
+-		ret += hlen;
++			s2n(TLSEXT_TYPE_padding, ret);
++			s2n(padding_len, ret);
++			memset(ret, 0, padding_len);
++			ret += padding_len;
++			}
+ 		}
+-	}
+ 
+ 
+ 	if ((extdatalen = ret-orig-2)== 0)