CVE-2010-4180 fix (from OpenSSL_1_0_0-stable)

ssl/s3_srvr.c

@@ -1019,6 +1019,10 @@ int ssl3_get_client_hello(SSL *s)
 				break;
 				}
 			}
+/* Disabled because it can be used in a ciphersuite downgrade
+ * attack: CVE-2010-4180.
+ */
+#if 0
 		if (j == 0 && (s->options & SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG) && (sk_SSL_CIPHER_num(ciphers) == 1))
 			{
 			/* Special case as client bug workaround: the previously used cipher may
@@ -1033,6 +1037,7 @@ int ssl3_get_client_hello(SSL *s)
 				j = 1;
 				}
 			}
+#endif
 		if (j == 0)
 			{
 			/* we need to have the cipher in the cipher