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/*
* 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/>
*
*/
#include "gnutls_int.h"
#include "errors.h"
#include "hello_ext.h"
#include "handshake.h"
#include "tls13/hello_retry.h"
#include "auth/cert.h"
#include "mbuffers.h"
int _gnutls13_send_hello_retry_request(gnutls_session_t session, unsigned again)
{
int ret;
mbuffer_st *bufel = NULL;
gnutls_buffer_st buf;
const version_entry_st *ver;
const uint8_t vbuf[2] = {0x03, 0x03};
if (again == 0) {
ver = get_version(session);
if (unlikely(ver == NULL || session->security_parameters.cs == NULL))
return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
ret = _gnutls_buffer_init_handshake_mbuffer(&buf);
if (ret < 0)
return gnutls_assert_val(ret);
ret = _gnutls_buffer_append_data(&buf, vbuf, 2);
if (ret < 0)
return gnutls_assert_val(ret);
ret = _gnutls_buffer_append_data(&buf,
HRR_RANDOM,
GNUTLS_RANDOM_SIZE);
if (ret < 0) {
gnutls_assert();
goto cleanup;
}
ret = _gnutls_buffer_append_data_prefix(&buf, 8,
session->security_parameters.session_id,
session->security_parameters.session_id_size);
if (ret < 0) {
gnutls_assert();
goto cleanup;
}
ret = _gnutls_buffer_append_data(&buf, session->security_parameters.cs->id, 2);
if (ret < 0) {
gnutls_assert();
goto cleanup;
}
/* compression */
ret = _gnutls_buffer_append_prefix(&buf, 8, 0);
if (ret < 0) {
gnutls_assert();
goto cleanup;
}
ret = _gnutls_gen_hello_extensions(session, &buf,
GNUTLS_EXT_FLAG_HRR,
GNUTLS_EXT_ANY);
if (ret < 0) {
gnutls_assert();
goto cleanup;
}
/* reset extensions sent by this session to allow re-sending them */
session->internals.used_exts = 0;
bufel = _gnutls_buffer_to_mbuffer(&buf);
}
return _gnutls_send_handshake(session, bufel, GNUTLS_HANDSHAKE_HELLO_RETRY_REQUEST);
cleanup:
_gnutls_buffer_clear(&buf);
return ret;
}
int
_gnutls13_recv_hello_retry_request(gnutls_session_t session,
gnutls_buffer_st *buf)
{
int ret;
uint8_t tmp[2];
const gnutls_cipher_suite_entry_st *cs;
const mac_entry_st *prf;
gnutls_datum_t session_id;
uint8_t random[GNUTLS_RANDOM_SIZE];
/* only under TLS 1.3 */
if (IS_DTLS(session))
return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
if (session->internals.hsk_flags & HSK_HRR_RECEIVED)
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET);
session->internals.hsk_flags |= HSK_HRR_RECEIVED;
/* version */
ret = _gnutls_buffer_pop_data(buf, tmp, 2);
if (ret < 0)
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
if (unlikely(tmp[0] != 0x03 || tmp[1] != 0x03))
return gnutls_assert_val(GNUTLS_E_UNSUPPORTED_VERSION_PACKET);
ret = _gnutls_buffer_pop_data(buf, random, GNUTLS_RANDOM_SIZE);
if (ret < 0)
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
if (memcmp(random, HRR_RANDOM, GNUTLS_RANDOM_SIZE) != 0) {
return gnutls_assert_val(GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER);
}
ret = _gnutls_buffer_pop_datum_prefix8(buf, &session_id);
if (ret < 0)
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
/* read ciphersuites */
ret = _gnutls_buffer_pop_data(buf, tmp, 2);
if (ret < 0)
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
cs = ciphersuite_to_entry(tmp);
if (unlikely(cs == NULL))
return gnutls_assert_val(GNUTLS_E_UNKNOWN_CIPHER_SUITE);
_gnutls_handshake_log("EXT[%p]: Hello Retry Request with %s\n", session, cs->name);
memcpy(session->internals.hrr_cs, cs->id, 2);
prf = mac_to_entry(cs->prf);
if (unlikely(prf == NULL))
return gnutls_assert_val(GNUTLS_E_UNKNOWN_CIPHER_SUITE);
/* compression */
ret = _gnutls_buffer_pop_data(buf, tmp, 1);
if (ret < 0)
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
if (unlikely(tmp[0] != 0))
return gnutls_assert_val(GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER);
ret = _gnutls13_handshake_hash_buffers_synth(session, prf, 1);
if (ret < 0)
return gnutls_assert_val(ret);
if (buf->length <= 2) {
/* no extensions present */
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_EXTENSIONS_LENGTH);
}
/* figure version first */
ret =
_gnutls_parse_hello_extensions(session, GNUTLS_EXT_FLAG_HRR,
GNUTLS_EXT_VERSION_NEG,
buf->data, buf->length);
if (ret < 0)
return gnutls_assert_val(ret);
/* parse the rest of extensions */
ret = _gnutls_parse_hello_extensions(session, GNUTLS_EXT_FLAG_HRR, GNUTLS_EXT_ANY,
buf->data, buf->length);
if (ret < 0)
return gnutls_assert_val(ret);
session->internals.used_exts = 0;
return 0;
}
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