/* * 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 * */ #include "gnutls_int.h" #include "auth.h" #include "errors.h" #include "num.h" #include "str.h" #include #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; }