Disable the HMAC-SHA256 cipher suites for SSLClientSocketOpenSSL.

net/socket/ssl_client_socket_openssl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // OpenSSL binding for SSLClientSocket. The class layout and general principle
 // of operation is derived from SSLClientSocketNSS.
 
 #include "net/socket/ssl_client_socket_openssl.h"
 
 #include <openssl/err.h>
@@ skipping 514 matching lines @@
 
   SSL_set_mode(ssl_, mode.set_mask);
   SSL_clear_mode(ssl_, mode.clear_mask);
 
   // Removing ciphers by ID from OpenSSL is a bit involved as we must use the
   // textual name with SSL_set_cipher_list because there is no public API to
   // directly remove a cipher by ID.
   STACK_OF(SSL_CIPHER)* ciphers = SSL_get_ciphers(ssl_);
   DCHECK(ciphers);
   // See SSLConfig::disabled_cipher_suites for description of the suites
-  // disabled by default. Note that !SHA384 only removes HMAC-SHA384 cipher
-  // suites, not GCM cipher suites with SHA384 as the handshake hash.
-  std::string command("DEFAULT:!NULL:!aNULL:!IDEA:!FZA:!SRP:!SHA384:!aECDH");
+  // disabled by default. Note that !SHA256 and !SHA384 only remove HMAC-SHA256
+  // and HMAC-SHA384 cipher suites, not GCM cipher suites with SHA256 or SHA384
+  // as the handshake hash.
+  std::string command("DEFAULT:!NULL:!aNULL:!IDEA:!FZA:!SRP:!SHA256:!SHA384:"
+                      "!aECDH:!AESGCM+AES256");
   // Walk through all the installed ciphers, seeing if any need to be
   // appended to the cipher removal |command|.
   for (int i = 0; i < sk_SSL_CIPHER_num(ciphers); ++i) {
     const SSL_CIPHER* cipher = sk_SSL_CIPHER_value(ciphers, i);
     const uint16 id = SSL_CIPHER_get_id(cipher);
     // Remove any ciphers with a strength of less than 80 bits. Note the NSS
     // implementation uses "effective" bits here but OpenSSL does not provide
     // this detail. This only impacts Triple DES: reports 112 vs. 168 bits,
     // both of which are greater than 80 anyway.
     bool disable = SSL_CIPHER_get_bits(cipher, NULL) < 80;
@@ skipping 878 matching lines @@
     net_log_.AddByteTransferEvent(NetLog::TYPE_SSL_SOCKET_BYTES_SENT, rv,
                                   user_write_buf_->data());
     return rv;
   }
 
   int err = SSL_get_error(ssl_, rv);
   return MapOpenSSLError(err, err_tracer);
 }
 
 }  // namespace net