net: don't add padding extension for SSLv3.

net/third_party/nss/ssl/ssl3con.c

 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /*
  * SSL3 Protocol
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /* TODO(ekr): Implement HelloVerifyRequest on server side. OK for now. */
 
@@ skipping 4957 matching lines @@
     sslSessionID *   sid;
     ssl3CipherSpec * cwSpec;
     SECStatus        rv;
     int              i;
     int              length;
     int              num_suites;
     int              actual_count = 0;
     PRBool           isTLS = PR_FALSE;
     PRBool           requestingResume = PR_FALSE;
     PRInt32          total_exten_len = 0;
-    unsigned         paddingExtensionLen;
+    PRInt32          paddingExtensionLen;

[wtc, 2013/11/11 21:50:33]

This variable receives the return value of ssl3_CalculatePaddingExtensionLength.
Since ssl3_CalculatePaddingExtensionLength cannot fail, it is better for this
variable to have the unsigned type.

[agl, 2013/11/12 16:21:57]

Done.

     unsigned         numCompressionMethods;
     PRInt32          flags;
 
     SSL_TRC(3, ("%d: SSL3[%d]: send client_hello handshake", SSL_GETPID(),
                 ss->fd));
 
     PORT_Assert( ss->opt.noLocks || ssl_HaveSSL3HandshakeLock(ss) );
     PORT_Assert( ss->opt.noLocks || ssl_HaveXmitBufLock(ss) );
 
     rv = ssl3_InitState(ss);
@@ skipping 252 matching lines @@
     if (IS_DTLS(ss)) {
         length += 1 + ss->ssl3.hs.cookieLen;
     }
 
     /* A padding extension may be included to ensure that the record containing
      * the ClientHello doesn't have a length between 256 and 511 bytes
      * (inclusive). Initial, ClientHello records with such lengths trigger bugs
      * in F5 devices.
      *
      * This is not done for DTLS nor for renegotiation. */
-    if (!IS_DTLS(ss) && !ss->firstHsDone) {
+    if (!IS_DTLS(ss) && isTLS && !ss->firstHsDone) {
         paddingExtensionLen = ssl3_CalculatePaddingExtensionLength(length);
         total_exten_len += paddingExtensionLen;
         length += paddingExtensionLen;
     } else {
         paddingExtensionLen = 0;
     }
 
     rv = ssl3_AppendHandshakeHeader(ss, client_hello, length);
     if (rv != SECSuccess) {
         return rv;      /* err set by ssl3_AppendHandshake* */
@@ skipping 7328 matching lines @@
             PORT_Free(ss->ssl3.hs.recvdFragments.buf);
         }
     }
 
     ss->ssl3.initialized = PR_FALSE;
 
     SECITEM_FreeItem(&ss->ssl3.nextProto, PR_FALSE);
 }
 
 /* End of ssl3con.c */