1 files changed, 385 insertions, 0 deletions
diff --git a/lib/ext/server_name.c b/lib/ext/server_name.c
new file mode 100644
index 0000000..d52c8d0
--- /dev/null
+++ b/lib/ext/server_name.c
@@ -0,0 +1,385 @@
+/*
+ * Copyright (C) 2002-2012 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 <https://www.gnu.org/licenses/>
+ *
+ */
+
+#include "gnutls_int.h"
+#include "auth.h"
+#include "errors.h"
+#include "num.h"
+#include "str.h"
+#include <ext/server_name.h>
+#include "hello_ext_lib.h"
+
+static int _gnutls_server_name_recv_params(gnutls_session_t session,
+					   const uint8_t * data,
+					   size_t data_size);
+static int _gnutls_server_name_send_params(gnutls_session_t session,
+					   gnutls_buffer_st * extdata);
+
+int
+_gnutls_server_name_set_raw(gnutls_session_t session,
+			    gnutls_server_name_type_t type,
+			    const void *name, size_t name_length);
+
+const hello_ext_entry_st ext_mod_server_name = {
+	.name = "Server Name Indication",
+	.tls_id = 0,
+	.gid = GNUTLS_EXTENSION_SERVER_NAME,
+	.validity = GNUTLS_EXT_FLAG_TLS | GNUTLS_EXT_FLAG_DTLS | GNUTLS_EXT_FLAG_CLIENT_HELLO |
+		    GNUTLS_EXT_FLAG_EE | GNUTLS_EXT_FLAG_TLS12_SERVER_HELLO,
+	.client_parse_point = GNUTLS_EXT_MANDATORY,
+	.server_parse_point = GNUTLS_EXT_MANDATORY,
+	.recv_func = _gnutls_server_name_recv_params,
+	.send_func = _gnutls_server_name_send_params,
+	.pack_func = _gnutls_hello_ext_default_pack,
+	.unpack_func = _gnutls_hello_ext_default_unpack,
+	.deinit_func = _gnutls_hello_ext_default_deinit,
+	.cannot_be_overriden = 1
+};
+
+/*
+ * In case of a server: if a NAME_DNS extension type is received then
+ * it stores into the session the value of NAME_DNS. The server may
+ * use gnutls_ext_get_server_name(), in order to access it.
+ *
+ * In case of a client: If a proper NAME_DNS extension type is found
+ * in the session then it sends the extension to the peer.
+ *
+ */
+static int
+_gnutls_server_name_recv_params(gnutls_session_t session,
+				const uint8_t * data, size_t data_size)
+{
+	const unsigned char *p;
+	uint16_t len, type;
+	gnutls_datum_t name;
+
+	if (session->security_parameters.entity == GNUTLS_SERVER) {
+		DECR_LENGTH_RET(data_size, 2, GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
+		len = _gnutls_read_uint16(data);
+		if (len == 0)
+			return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
+
+		if (len != data_size) {
+			gnutls_assert();
+			return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
+		}
+
+		p = data + 2;
+
+		while (data_size > 0) {
+			DECR_LEN(data_size, 1);
+			type = *p;
+			p++;
+
+			DECR_LEN(data_size, 2);
+			len = _gnutls_read_uint16(p);
+			p += 2;
+
+			if (len == 0) {
+				_gnutls_handshake_log
+				    ("HSK[%p]: Received server name size of zero\n",
+				     session);
+				return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
+			}
+
+			DECR_LEN(data_size, len);
+
+			if (type == 0) { /* NAME_DNS */
+				if (!_gnutls_dnsname_is_valid((char*)p, len)) {
+					_gnutls_handshake_log
+					    ("HSK[%p]: Server name is not acceptable: '%.*s'\n",
+					     session, (int) len, p);
+					return gnutls_assert_val(GNUTLS_E_RECEIVED_DISALLOWED_NAME);
+				}
+
+				name.data = (void*)p;
+				name.size = len;
+
+				_gnutls_hello_ext_unset_priv(session, GNUTLS_EXTENSION_SERVER_NAME);
+				return _gnutls_hello_ext_set_datum(session,
+					     GNUTLS_EXTENSION_SERVER_NAME,
+					     &name);
+			}
+			p += len;
+
+		}
+
+
+	}
+
+	return 0;
+}
+
+/* returns data_size or a negative number on failure
+ */
+static int
+_gnutls_server_name_send_params(gnutls_session_t session,
+				gnutls_buffer_st * extdata)
+{
+	int total_size = 0, ret;
+	gnutls_datum_t name;
+
+	ret =
+	    _gnutls_hello_ext_get_datum(session, GNUTLS_EXTENSION_SERVER_NAME,
+					&name);
+	if (ret < 0)
+		return 0;
+
+	/* this function sends the client extension data (dnsname)
+	 */
+	if (session->security_parameters.entity == GNUTLS_CLIENT) {
+		if (name.size == 0)
+			return 0;
+
+		/* uint8_t + uint16_t + size
+		 */
+		total_size = 2 + 1 + 2 + name.size;
+
+		/* UINT16: write total size of all names
+		 */
+		ret =
+		    _gnutls_buffer_append_prefix(extdata, 16,
+						 total_size - 2);
+		if (ret < 0)
+			return gnutls_assert_val(ret);
+
+		/* UINT8: type of this extension
+		 * UINT16: size of the first name
+		 * LEN: the actual server name.
+		 */
+		ret =
+		    _gnutls_buffer_append_prefix(extdata, 8, 0);
+		if (ret < 0)
+			return gnutls_assert_val(ret);
+
+		_gnutls_debug_log("HSK[%p]: sent server name: '%.*s'\n", session, name.size, name.data);
+
+		ret =
+		    _gnutls_buffer_append_data_prefix
+			    (extdata, 16,
+			     name.data, name.size);
+		if (ret < 0)
+			return gnutls_assert_val(ret);
+	} else {
+		return 0;
+	}
+
+	return total_size;
+}
+
+/**
+ * gnutls_server_name_get:
+ * @session: is a #gnutls_session_t type.
+ * @data: will hold the data
+ * @data_length: will hold the data length. Must hold the maximum size of data.
+ * @type: will hold the server name indicator type
+ * @indx: is the index of the server_name
+ *
+ * This function will allow you to get the name indication (if any), a
+ * client has sent.  The name indication may be any of the enumeration
+ * gnutls_server_name_type_t.
+ *
+ * If @type is GNUTLS_NAME_DNS, then this function is to be used by
+ * servers that support virtual hosting, and the data will be a null
+ * terminated IDNA ACE string (prior to GnuTLS 3.4.0 it was a UTF-8 string).
+ *
+ * If @data has not enough size to hold the server name
+ * GNUTLS_E_SHORT_MEMORY_BUFFER is returned, and @data_length will
+ * hold the required size.
+ *
+ * @indx is used to retrieve more than one server names (if sent by
+ * the client).  The first server name has an index of 0, the second 1
+ * and so on.  If no name with the given index exists
+ * GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE is returned.
+ *
+ * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, on UTF-8
+ *  decoding error %GNUTLS_E_IDNA_ERROR is returned, otherwise a negative
+ *  error code is returned.
+ **/
+int
+gnutls_server_name_get(gnutls_session_t session, void *data,
+		       size_t * data_length,
+		       unsigned int *type, unsigned int indx)
+{
+	char *_data = data;
+	gnutls_datum_t name;
+	int ret;
+
+	if (session->security_parameters.entity == GNUTLS_CLIENT) {
+		gnutls_assert();
+		return GNUTLS_E_INVALID_REQUEST;
+	}
+
+	if (indx != 0)
+		return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;
+
+	ret =
+	    _gnutls_hello_ext_get_datum(session, GNUTLS_EXTENSION_SERVER_NAME, &name);
+	if (ret < 0) {
+		gnutls_assert();
+		return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;
+	}
+
+	if (name.size == 0) {
+		return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;
+	}
+
+	*type = GNUTLS_NAME_DNS;
+
+	if (*data_length > name.size) { /* greater since we need one extra byte for the null */
+		*data_length = name.size;
+		memcpy(data, name.data, *data_length);
+
+		/* null terminate */
+		_data[(*data_length)] = 0;
+
+	} else {
+		*data_length = name.size + 1;
+		ret = GNUTLS_E_SHORT_MEMORY_BUFFER;
+		goto cleanup;
+	}
+
+	ret = 0;
+ cleanup:
+	return ret;
+}
+
+/* This does not do any conversion not perform any check */
+int
+_gnutls_server_name_set_raw(gnutls_session_t session,
+			    gnutls_server_name_type_t type,
+			    const void *name, size_t name_length)
+{
+	int ret;
+	gnutls_datum_t dname;
+
+	if (name_length >= MAX_SERVER_NAME_SIZE) {
+		return GNUTLS_E_INVALID_REQUEST;
+	}
+
+	_gnutls_hello_ext_unset_priv(session, GNUTLS_EXTENSION_SERVER_NAME);
+
+	dname.data = (void*)name;
+	dname.size = name_length;
+
+	ret = _gnutls_hello_ext_set_datum(session, GNUTLS_EXTENSION_SERVER_NAME, &dname);
+	if (ret < 0)
+		return gnutls_assert_val(ret);
+
+	return 0;
+}
+
+/**
+ * gnutls_server_name_set:
+ * @session: is a #gnutls_session_t type.
+ * @type: specifies the indicator type
+ * @name: is a string that contains the server name.
+ * @name_length: holds the length of name excluding the terminating null byte
+ *
+ * This function is to be used by clients that want to inform (via a
+ * TLS extension mechanism) the server of the name they connected to.
+ * This should be used by clients that connect to servers that do
+ * virtual hosting.
+ *
+ * The value of @name depends on the @type type.  In case of
+ * %GNUTLS_NAME_DNS, a UTF-8 null-terminated domain name string,
+ * without the trailing dot, is expected.
+ *
+ * IPv4 or IPv6 addresses are not permitted to be set by this function.
+ * If the function is called with a name of @name_length zero it will clear
+ * all server names set.
+ *
+ * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned,
+ *   otherwise a negative error code is returned.
+ **/
+int
+gnutls_server_name_set(gnutls_session_t session,
+		       gnutls_server_name_type_t type,
+		       const void *name, size_t name_length)
+{
+	int ret;
+	gnutls_datum_t idn_name = {NULL,0};
+
+	if (session->security_parameters.entity == GNUTLS_SERVER) {
+		gnutls_assert();
+		return GNUTLS_E_INVALID_REQUEST;
+	}
+
+	if (name_length == 0) { /* unset extension */
+		_gnutls_hello_ext_unset_priv(session, GNUTLS_EXTENSION_SERVER_NAME);
+		return 0;
+	}
+
+	ret = gnutls_idna_map(name, name_length, &idn_name, 0);
+	if (ret < 0) {
+		 _gnutls_debug_log("unable to convert name %s to IDNA2008 format\n", (char*)name);
+		 return ret;
+	}
+
+	name = idn_name.data;
+	name_length = idn_name.size;
+
+	ret = _gnutls_server_name_set_raw(session, type, name, name_length);
+	gnutls_free(idn_name.data);
+
+	return ret;
+}
+
+unsigned _gnutls_server_name_matches_resumed(gnutls_session_t session)
+{
+	gnutls_datum_t name1, name2;
+	int ret;
+
+	ret =
+	    _gnutls_hello_ext_get_datum(session,
+					GNUTLS_EXTENSION_SERVER_NAME,
+					&name1);
+	if (ret < 0) { /* no server name in this session */
+		name1.data = NULL;
+		name1.size = 0;
+	}
+
+	ret =
+	    _gnutls_hello_ext_get_resumed_datum(session,
+						GNUTLS_EXTENSION_SERVER_NAME,
+						&name2);
+	if (ret < 0) { /* no server name in this session */
+		name2.data = NULL;
+		name2.size = 0;
+	}
+
+	if (name1.data == NULL || name2.data == NULL) {
+		if (name1.data == name2.data)
+			return 1;
+		else
+			return 0;
+	}
+
+	if (name1.size != name2.size)
+		return 0;
+
+	if (memcmp(name1.data, name2.data, name1.size) != 0)
+		return 0;
+
+	return 1;
+}