OpenSSL: add support for the TLS padding extension.

openssl/patches/paddingext.patch

Index: openssl/patches/paddingext.patch
diff --git a/openssl/patches/paddingext.patch b/openssl/patches/paddingext.patch
new file mode 100644
index 0000000000000000000000000000000000000000..fbc3d063cebcbc87efd3f3f2e9f04e3cf45bde6b
--- /dev/null
+++ b/openssl/patches/paddingext.patch
@@ -0,0 +1,96 @@
+From 61a9671951205d66382556b2502993ffc9201f59 Mon Sep 17 00:00:00 2001
+From: Adam Langley <agl@chromium.org>
+Date: Wed, 11 Dec 2013 16:25:17 -0500
+Subject: [PATCH 57/57] Add padding extension.
+
+This change adds a padding extension, when needed, in order to work
+around bugs in F5 terminators.
+---
+ ssl/t1_lib.c | 20 ++++++++++++++++++++
+ ssl/tls1.h   |  4 ++++
+ 2 files changed, 24 insertions(+)
+
+diff --git a/ssl/s23_clnt.c b/ssl/s23_clnt.c
+index 47673e7..94e9692 100644
+--- a/ssl/s23_clnt.c
++++ b/ssl/s23_clnt.c
+@@ -466,7 +466,10 @@ 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 */
++			/* 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. */
+ 			d = p = &(buf[9]);
+ 			
+ 			*(p++) = version_major;
+diff --git a/ssl/s3_clnt.c b/ssl/s3_clnt.c
+index a657360..faa8d36 100644
+--- a/ssl/s3_clnt.c
++++ b/ssl/s3_clnt.c
+@@ -752,7 +752,9 @@ int ssl3_client_hello(SSL *s)
+ 		if (RAND_pseudo_bytes(p,SSL3_RANDOM_SIZE-4) <= 0)
+ 			goto err;
+ 
+-		/* Do the message type and length last */
++		/* Do the message type and length last.
++		 * Note: the code to add the padding extension in t1_lib.c
++		 * depends on the size of this prefix. */
+ 		d=p= &(buf[4]);
+ 
+ 		/* version indicates the negotiated version: for example from
+diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
+index 5578056..f9ad9d9 100644
+--- a/ssl/t1_lib.c
++++ b/ssl/t1_lib.c
+@@ -695,6 +695,31 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned cha
+                 }
+ #endif
+ 
++	/* 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)
++		{
++		hlen = 0x200 - hlen;
++		if (hlen >= 4)
++			hlen -= 4;
++		else
++			hlen = 0;
++
++		s2n(TLSEXT_TYPE_padding, ret);
++		s2n(hlen, ret);
++		memset(ret, 0, hlen);
++		ret += hlen;
++		}
++	}
++
++
+ 	if ((extdatalen = ret-p-2)== 0) 
+ 		return p;
+ 
+diff --git a/ssl/tls1.h b/ssl/tls1.h
+index ecf5da7..df8f482 100644
+--- a/ssl/tls1.h
++++ b/ssl/tls1.h
+@@ -255,6 +255,10 @@ extern "C" {
+ #define TLSEXT_TYPE_channel_id			30031
+ #define TLSEXT_TYPE_channel_id_new		30032
+ 
++/* See https://tools.ietf.org/html/draft-agl-tls-padding-02
++ * Number not yet IANA assigned. */
++#define TLSEXT_TYPE_padding			35655
++
+ /* NameType value from RFC 3546 */
+ #define TLSEXT_NAMETYPE_host_name 0
+ /* status request value from RFC 3546 */
+-- 
+1.8.5.1