1 files changed, 124 insertions, 0 deletions
diff --git a/lib/ext/ec_point_formats.c b/lib/ext/ec_point_formats.c
new file mode 100644
index 0000000000..657eb6625d
--- /dev/null
+++ b/lib/ext/ec_point_formats.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2011-2012 Free Software Foundation, Inc.
+ * Copyright (C) 2017 Red Hat, Inc.
+ *
+ * Author: Nikos Mavrogiannopoulos
+ *
+ * This file is part of GnuTLS.
+ *
+ * The GnuTLS is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+/* This file contains the code for the Elliptic Curve Point Formats extension.
+ */
+
+#include "ext/ec_point_formats.h"
+#include "str.h"
+#include "state.h"
+#include <gnutls/gnutls.h>
+
+
+static int _gnutls_supported_ec_point_formats_recv_params(gnutls_session_t session,
+						const uint8_t * data,
+						size_t data_size);
+static int _gnutls_supported_ec_point_formats_send_params(gnutls_session_t session,
+						gnutls_buffer_st * extdata);
+
+
+const hello_ext_entry_st ext_mod_supported_ec_point_formats = {
+	.name = "Supported EC Point Formats",
+	.tls_id = 11,
+	.gid = GNUTLS_EXTENSION_SUPPORTED_EC_POINT_FORMATS,
+	.parse_type = GNUTLS_EXT_TLS,
+	.validity = GNUTLS_EXT_FLAG_TLS | GNUTLS_EXT_FLAG_DTLS |
+		    GNUTLS_EXT_FLAG_CLIENT_HELLO | GNUTLS_EXT_FLAG_TLS12_SERVER_HELLO,
+	.recv_func = _gnutls_supported_ec_point_formats_recv_params,
+	.send_func = _gnutls_supported_ec_point_formats_send_params,
+	.pack_func = NULL,
+	.unpack_func = NULL,
+	.deinit_func = NULL
+};
+
+
+/* Receive point formats
+ */
+static int
+_gnutls_supported_ec_point_formats_recv_params(gnutls_session_t session,
+				     const uint8_t * data,
+				     size_t _data_size)
+{
+	int len, i;
+	int uncompressed = 0;
+	int data_size = _data_size;
+
+	if (session->security_parameters.entity == GNUTLS_CLIENT) {
+		if (data_size < 1)
+			return
+			    gnutls_assert_val
+			    (GNUTLS_E_RECEIVED_ILLEGAL_EXTENSION);
+
+		len = data[0];
+		if (len < 1)
+			return
+			    gnutls_assert_val
+			    (GNUTLS_E_RECEIVED_ILLEGAL_EXTENSION);
+
+		DECR_LEN(data_size, len + 1);
+
+		for (i = 1; i <= len; i++)
+			if (data[i] == 0) {	/* uncompressed */
+				uncompressed = 1;
+				break;
+			}
+
+		if (uncompressed == 0)
+			return
+			    gnutls_assert_val
+			    (GNUTLS_E_UNKNOWN_PK_ALGORITHM);
+	} else {
+		/* only sanity check here. We only support uncompressed points
+		 * and a client must support it thus nothing to check.
+		 */
+		if (_data_size < 1)
+			return
+			    gnutls_assert_val
+			    (GNUTLS_E_RECEIVED_ILLEGAL_EXTENSION);
+	}
+
+	return 0;
+}
+
+/* returns data_size or a negative number on failure
+ */
+static int
+_gnutls_supported_ec_point_formats_send_params(gnutls_session_t session,
+				     gnutls_buffer_st * extdata)
+{
+	const uint8_t p[2] = { 0x01, 0x00 };	/* only support uncompressed point format */
+	int ret;
+
+	if (session->security_parameters.entity == GNUTLS_SERVER
+	    && !_gnutls_session_is_ecc(session))
+		return 0;
+
+	if (session->internals.priorities->groups.size > 0) {
+		ret = _gnutls_buffer_append_data(extdata, p, 2);
+		if (ret < 0)
+			return gnutls_assert_val(ret);
+
+		return 2;
+	}
+	return 0;
+}