Additional workaround for PR#2771

If OPENSSL_MAX_TLS1_2_CIPHER_LENGTH is set then limit the size of client
ciphersuites to this value. A value of 50 should be sufficient.

Document workarounds in CHANGES.

ssl/s23_clnt.c

@@ -467,6 +467,15 @@ static int ssl23_client_hello(SSL *s)
 				SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
 				return -1;
 				}
+#ifdef OPENSSL_MAX_TLS1_2_CIPHER_LENGTH
+			/* Some servers hang if client hello > 256 bytes
+			 * as hack workaround chop number of supported ciphers
+			 * to keep it well below this if we use TLS v1.2
+			 */
+			if (TLS1_get_version(s) >= TLS1_2_VERSION
+				&& i > OPENSSL_MAX_TLS1_2_CIPHER_LENGTH)
+				i = OPENSSL_MAX_TLS1_2_CIPHER_LENGTH & ~1;
+#endif
 			s2n(i,p);
 			p+=i;