/*
* Copyright (C) 2000-2016 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/>
*
*/
#include "gnutls_int.h"
#include "errors.h"
#include "debug.h"
#include <session_pack.h>
#include <datum.h>
#include "state.h"
/**
* gnutls_session_get_data:
* @session: is a #gnutls_session_t type.
* @session_data: is a pointer to space to hold the session.
* @session_data_size: is the session_data's size, or it will be set by the function.
*
* Returns all session parameters needed to be stored to support resumption.
* The client should call this, and store the returned session data. A session
* may be resumed later by calling gnutls_session_set_data().
*
* This function will fail if called prior to handshake completion. In
* case of false start TLS, the handshake completes only after data have
* been successfully received from the peer.
*
* Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise
* an error code is returned.
**/
int
gnutls_session_get_data(gnutls_session_t session,
void *session_data, size_t * session_data_size)
{
gnutls_datum_t psession;
int ret;
ret = gnutls_session_get_data2(session, &psession);
if (ret < 0) {
gnutls_assert();
return ret;
}
if (psession.size > *session_data_size) {
*session_data_size = psession.size;
ret = GNUTLS_E_SHORT_MEMORY_BUFFER;
goto error;
}
*session_data_size = psession.size;
if (session_data != NULL)
memcpy(session_data, psession.data, psession.size);
ret = 0;
error:
_gnutls_free_datum(&psession);
return ret;
}
/**
* gnutls_session_get_data2:
* @session: is a #gnutls_session_t type.
* @data: is a pointer to a datum that will hold the session.
*
* Returns all session parameters needed to be stored to support resumption.
* The client should call this, and store the returned session data. A session
* may be resumed later by calling gnutls_session_set_data().
*
* The returned @data are allocated and must be released using gnutls_free().
*
* This function will fail if called prior to handshake completion. In
* case of false start TLS, the handshake completes only after data have
* been successfully received from the peer.
*
* Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise
* an error code is returned.
**/
int
gnutls_session_get_data2(gnutls_session_t session, gnutls_datum_t *data)
{
int ret;
if (data == NULL) {
return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
}
if (gnutls_session_is_resumed(session) && session->internals.resumption_data.data) {
ret = _gnutls_set_datum(data, session->internals.resumption_data.data, session->internals.resumption_data.size);
if (ret < 0)
return gnutls_assert_val(ret);
return 0;
}
if (session->internals.resumable == RESUME_FALSE)
return GNUTLS_E_INVALID_SESSION;
ret = _gnutls_session_pack(session, data);
if (ret < 0) {
gnutls_assert();
return ret;
}
return 0;
}
/**
* gnutls_session_get_id:
* @session: is a #gnutls_session_t type.
* @session_id: is a pointer to space to hold the session id.
* @session_id_size: initially should contain the maximum @session_id size and will be updated.
*
* Returns the current session ID. This can be used if you want to
* check if the next session you tried to resume was actually
* resumed. That is because resumed sessions share the same session ID
* with the original session.
*
* The session ID is selected by the server, that identify the
* current session. In all supported TLS protocols, the session id
* is less than %GNUTLS_MAX_SESSION_ID_SIZE.
*
* Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise
* an error code is returned.
**/
int
gnutls_session_get_id(gnutls_session_t session,
void *session_id, size_t * session_id_size)
{
size_t given_session_id_size = *session_id_size;
*session_id_size = session->security_parameters.session_id_size;
/* just return the session size */
if (session_id == NULL) {
return 0;
}
if (given_session_id_size <
session->security_parameters.session_id_size) {
return GNUTLS_E_SHORT_MEMORY_BUFFER;
}
memcpy(session_id, &session->security_parameters.session_id,
*session_id_size);
return 0;
}
/**
* gnutls_session_get_id2:
* @session: is a #gnutls_session_t type.
* @session_id: will point to the session ID.
*
* Returns the current session ID. The returned data should be
* treated as constant.
*
* Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise
* an error code is returned.
*
* Since: 3.1.4
**/
int
gnutls_session_get_id2(gnutls_session_t session,
gnutls_datum_t * session_id)
{
session_id->size = session->security_parameters.session_id_size;
session_id->data = session->security_parameters.session_id;
return 0;
}
/**
* gnutls_session_set_data:
* @session: is a #gnutls_session_t type.
* @session_data: is a pointer to space to hold the session.
* @session_data_size: is the session's size
*
* Sets all session parameters, in order to resume a previously
* established session. The session data given must be the one
* returned by gnutls_session_get_data(). This function should be
* called before gnutls_handshake().
*
* Keep in mind that session resuming is advisory. The server may
* choose not to resume the session, thus a full handshake will be
* performed.
*
* Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise
* an error code is returned.
**/
int
gnutls_session_set_data(gnutls_session_t session,
const void *session_data, size_t session_data_size)
{
int ret;
gnutls_datum_t psession;
psession.data = (uint8_t *) session_data;
psession.size = session_data_size;
if (session_data == NULL || session_data_size == 0) {
gnutls_assert();
return GNUTLS_E_INVALID_REQUEST;
}
ret = _gnutls_session_unpack(session, &psession);
if (ret < 0) {
gnutls_assert();
return ret;
}
session->internals.resumption_requested = 1;
if (session->internals.resumption_data.data != NULL)
gnutls_free(session->internals.resumption_data.data);
_gnutls_set_datum(&session->internals.resumption_data, session_data, session_data_size);
return 0;
}
/**
* gnutls_session_force_valid:
* @session: is a #gnutls_session_t type.
*
* Clears the invalid flag in a session. That means
* that sessions were corrupt or invalid data were received
* can be re-used. Use only when debugging or experimenting
* with the TLS protocol. Should not be used in typical
* applications.
*
**/
void gnutls_session_force_valid(gnutls_session_t session)
{
session->internals.invalid_connection = 0;
}
#define DESC_SIZE 64
/**
* gnutls_session_get_desc:
* @session: is a gnutls session
*
* This function returns a string describing the current session.
* The string is null terminated and allocated using gnutls_malloc().
*
* If initial negotiation is not complete when this function is called,
* %NULL will be returned.
*
* Returns: a description of the protocols and algorithms in the current session.
*
* Since: 3.1.10
**/
char *gnutls_session_get_desc(gnutls_session_t session)
{
gnutls_kx_algorithm_t kx;
const char *kx_str, *sign_str;
unsigned type;
char kx_name[64];
char proto_name[32];
char _group_name[24];
const char *group_name = NULL;
unsigned dh_bits = 0;
unsigned mac_id;
unsigned sign_algo;
char *desc;
const struct gnutls_group_entry_st *group = get_group(session);
if (session->internals.initial_negotiation_completed == 0)
return NULL;
kx = session->security_parameters.cs->kx_algorithm;
if (group)
group_name = group->name;
#if defined(ENABLE_DHE) || defined(ENABLE_ANON)
if (group_name == NULL && _gnutls_kx_is_dhe(kx)) {
dh_bits = gnutls_dh_get_prime_bits(session);
snprintf(_group_name, sizeof(_group_name), "CUSTOM%u", dh_bits);
group_name = _group_name;
}
#endif
/* Key exchange - Signature algorithm */
/* DHE-3072 - RSA-PSS-2048 */
/* ECDHE-SECP256R1 - ECDSA-SECP256R1 */
sign_algo = gnutls_sign_algorithm_get(session);
sign_str = gnutls_sign_get_name(sign_algo);
kx_str = gnutls_kx_get_name(kx);
if (kx_str) {
if (kx == GNUTLS_KX_ECDHE_ECDSA || kx == GNUTLS_KX_ECDHE_RSA ||
kx == GNUTLS_KX_ECDHE_PSK) {
if (sign_str)
snprintf(kx_name, sizeof(kx_name), "(ECDHE-%s)-(%s)",
group_name, sign_str);
else
snprintf(kx_name, sizeof(kx_name), "(ECDHE-%s)",
group_name);
} else if (kx == GNUTLS_KX_DHE_DSS || kx == GNUTLS_KX_DHE_RSA ||
kx == GNUTLS_KX_DHE_PSK) {
if (sign_str)
snprintf(kx_name, sizeof(kx_name), "(DHE-%s)-(%s)", group_name, sign_str);
else
snprintf(kx_name, sizeof(kx_name), "(DHE-%s)", group_name);
} else if (kx == GNUTLS_KX_RSA) {
/* Possible enhancement: include the certificate bits */
snprintf(kx_name, sizeof(kx_name), "(RSA)");
} else {
snprintf(kx_name, sizeof(kx_name), "(%s)",
kx_str);
}
} else {
strcpy(kx_name, "(NULL)");
}
type = gnutls_certificate_type_get(session);
if (type == GNUTLS_CRT_X509)
snprintf(proto_name, sizeof(proto_name), "%s",
gnutls_protocol_get_name(get_num_version
(session)));
else
snprintf(proto_name, sizeof(proto_name), "%s-%s",
gnutls_protocol_get_name(get_num_version
(session)),
gnutls_certificate_type_get_name(type));
desc = gnutls_malloc(DESC_SIZE);
if (desc == NULL)
return NULL;
mac_id = gnutls_mac_get(session);
if (mac_id == GNUTLS_MAC_AEAD) { /* no need to print */
snprintf(desc, DESC_SIZE,
"(%s)-%s-(%s)",
proto_name,
kx_name,
gnutls_cipher_get_name(gnutls_cipher_get(session)));
} else {
snprintf(desc, DESC_SIZE,
"(%s)-%s-(%s)-(%s)",
proto_name,
kx_name,
gnutls_cipher_get_name(gnutls_cipher_get(session)),
gnutls_mac_get_name(mac_id));
}
return desc;
}
/**
* gnutls_session_set_id:
* @session: is a #gnutls_session_t type.
* @sid: the session identifier
*
* This function sets the session ID to be used in a client hello.
* This is a function intended for exceptional uses. Do not use this
* function unless you are implementing a custom protocol.
*
* To set session resumption parameters use gnutls_session_set_data() instead.
*
* Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise
* an error code is returned.
*
* Since: 3.2.1
**/
int
gnutls_session_set_id(gnutls_session_t session, const gnutls_datum_t * sid)
{
if (session->security_parameters.entity == GNUTLS_SERVER ||
sid->size > GNUTLS_MAX_SESSION_ID_SIZE)
return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
memset(&session->internals.resumed_security_parameters, 0,
sizeof(session->internals.resumed_security_parameters));
session->internals.resumed_security_parameters.session_id_size =
sid->size;
memcpy(session->internals.resumed_security_parameters.session_id,
sid->data, sid->size);
return 0;
}