/*
* Copyright (C) 2000-2018 Free Software Foundation, Inc.
* Copyright (C) 2012-2018 Nikos Mavrogiannopoulos
* Copyright (C) 2018 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/>
*
*/
/* Functions that are record layer specific, are included in this file.
*/
/* allocate this many bytes more when encrypting or decrypting, to
* compensate for broken backends such as cryptodev.
*/
#define CIPHER_SLACK_SIZE 32
#include "gnutls_int.h"
#include "errors.h"
#include "debug.h"
#include "cipher.h"
#include "buffers.h"
#include "mbuffers.h"
#include "handshake.h"
#include "hash_int.h"
#include "cipher_int.h"
#include "algorithms.h"
#include "db.h"
#include "auth.h"
#include "num.h"
#include "record.h"
#include "datum.h"
#include "constate.h"
#include "tls13/key_update.h"
#include <ext/heartbeat.h>
#include <state.h>
#include <dtls.h>
#include <dh.h>
#include <random.h>
#include <xsize.h>
#include "locks.h"
struct tls_record_st {
uint16_t header_size;
uint8_t version[2];
uint64_t sequence; /* DTLS */
uint16_t length;
uint16_t packet_size; /* header_size + length */
content_type_t type;
uint16_t epoch; /* valid in DTLS only */
#ifdef ENABLE_SSL2
unsigned v2:1; /* whether an SSLv2 client hello */
#endif
/* the data */
};
/**
* gnutls_record_disable_padding:
* @session: is a #gnutls_session_t type.
*
* Used to disabled padding in TLS 1.0 and above. Normally you do not
* need to use this function, but there are buggy clients that
* complain if a server pads the encrypted data. This of course will
* disable protection against statistical attacks on the data.
*
* This function is defunct since 3.1.7. Random padding is disabled
* by default unless requested using gnutls_record_send_range().
*
**/
void gnutls_record_disable_padding(gnutls_session_t session)
{
return;
}
/**
* gnutls_transport_set_ptr:
* @session: is a #gnutls_session_t type.
* @ptr: is the value.
*
* Used to set the first argument of the transport function (for push
* and pull callbacks). In berkeley style sockets this function will set the
* connection descriptor.
*
**/
void
gnutls_transport_set_ptr(gnutls_session_t session,
gnutls_transport_ptr_t ptr)
{
session->internals.transport_recv_ptr = ptr;
session->internals.transport_send_ptr = ptr;
}
/**
* gnutls_transport_set_ptr2:
* @session: is a #gnutls_session_t type.
* @recv_ptr: is the value for the pull function
* @send_ptr: is the value for the push function
*
* Used to set the first argument of the transport function (for push
* and pull callbacks). In berkeley style sockets this function will set the
* connection descriptor. With this function you can use two different
* pointers for receiving and sending.
**/
void
gnutls_transport_set_ptr2(gnutls_session_t session,
gnutls_transport_ptr_t recv_ptr,
gnutls_transport_ptr_t send_ptr)
{
session->internals.transport_send_ptr = send_ptr;
session->internals.transport_recv_ptr = recv_ptr;
}
/**
* gnutls_transport_set_int2:
* @session: is a #gnutls_session_t type.
* @recv_fd: is socket descriptor for the pull function
* @send_fd: is socket descriptor for the push function
*
* This function sets the first argument of the transport functions,
* such as send() and recv() for the default callbacks using the
* system's socket API. With this function you can set two different
* descriptors for receiving and sending.
*
* This function is equivalent to calling gnutls_transport_set_ptr2()
* with the descriptors, but requires no casts.
*
* Since: 3.1.9
**/
void
gnutls_transport_set_int2(gnutls_session_t session,
int recv_fd, int send_fd)
{
session->internals.transport_send_ptr =
(gnutls_transport_ptr_t) (long) send_fd;
session->internals.transport_recv_ptr =
(gnutls_transport_ptr_t) (long) recv_fd;
}
#if 0
/* this will be a macro */
/**
* gnutls_transport_set_int:
* @session: is a #gnutls_session_t type.
* @fd: is the socket descriptor for the connection.
*
* This function sets the first argument of the transport function, such
* as send() and recv() for the default callbacks using the
* system's socket API.
*
* This function is equivalent to calling gnutls_transport_set_ptr()
* with the descriptor, but requires no casts.
*
* Since: 3.1.9
*
**/
void gnutls_transport_set_int(gnutls_session_t session, int fd)
{
session->internals.transport_recv_ptr =
(gnutls_transport_ptr_t) (long) fd;
session->internals.transport_send_ptr =
(gnutls_transport_ptr_t) (long) fd;
}
#endif
/**
* gnutls_transport_get_ptr:
* @session: is a #gnutls_session_t type.
*
* Used to get the first argument of the transport function (like
* PUSH and PULL). This must have been set using
* gnutls_transport_set_ptr().
*
* Returns: The first argument of the transport function.
**/
gnutls_transport_ptr_t gnutls_transport_get_ptr(gnutls_session_t session)
{
return session->internals.transport_recv_ptr;
}
/**
* gnutls_transport_get_ptr2:
* @session: is a #gnutls_session_t type.
* @recv_ptr: will hold the value for the pull function
* @send_ptr: will hold the value for the push function
*
* Used to get the arguments of the transport functions (like PUSH
* and PULL). These should have been set using
* gnutls_transport_set_ptr2().
**/
void
gnutls_transport_get_ptr2(gnutls_session_t session,
gnutls_transport_ptr_t * recv_ptr,
gnutls_transport_ptr_t * send_ptr)
{
*recv_ptr = session->internals.transport_recv_ptr;
*send_ptr = session->internals.transport_send_ptr;
}
/**
* gnutls_transport_get_int2:
* @session: is a #gnutls_session_t type.
* @recv_int: will hold the value for the pull function
* @send_int: will hold the value for the push function
*
* Used to get the arguments of the transport functions (like PUSH
* and PULL). These should have been set using
* gnutls_transport_set_int2().
*
* Since: 3.1.9
**/
void
gnutls_transport_get_int2(gnutls_session_t session,
int *recv_int, int *send_int)
{
*recv_int = (long) session->internals.transport_recv_ptr;
*send_int = (long) session->internals.transport_send_ptr;
}
/**
* gnutls_transport_get_int:
* @session: is a #gnutls_session_t type.
*
* Used to get the first argument of the transport function (like
* PUSH and PULL). This must have been set using
* gnutls_transport_set_int().
*
* Returns: The first argument of the transport function.
*
* Since: 3.1.9
**/
int gnutls_transport_get_int(gnutls_session_t session)
{
return (long) session->internals.transport_recv_ptr;
}
/**
* gnutls_bye:
* @session: is a #gnutls_session_t type.
* @how: is an integer
*
* Terminates the current TLS/SSL connection. The connection should
* have been initiated using gnutls_handshake(). @how should be one
* of %GNUTLS_SHUT_RDWR, %GNUTLS_SHUT_WR.
*
* In case of %GNUTLS_SHUT_RDWR the TLS session gets
* terminated and further receives and sends will be disallowed. If
* the return value is zero you may continue using the underlying
* transport layer. %GNUTLS_SHUT_RDWR sends an alert containing a close
* request and waits for the peer to reply with the same message.
*
* In case of %GNUTLS_SHUT_WR the TLS session gets terminated
* and further sends will be disallowed. In order to reuse the
* connection you should wait for an EOF from the peer.
* %GNUTLS_SHUT_WR sends an alert containing a close request.
*
* Note that not all implementations will properly terminate a TLS
* connection. Some of them, usually for performance reasons, will
* terminate only the underlying transport layer, and thus not
* distinguishing between a malicious party prematurely terminating
* the connection and normal termination.
*
* This function may also return %GNUTLS_E_AGAIN or
* %GNUTLS_E_INTERRUPTED; cf. gnutls_record_get_direction().
*
* Returns: %GNUTLS_E_SUCCESS on success, or an error code, see
* function documentation for entire semantics.
**/
int gnutls_bye(gnutls_session_t session, gnutls_close_request_t how)
{
int ret = 0;
switch (BYE_STATE) {
case BYE_STATE0:
ret = _gnutls_io_write_flush(session);
BYE_STATE = BYE_STATE0;
if (ret < 0) {
gnutls_assert();
return ret;
}
FALLTHROUGH;
case BYE_STATE1:
ret =
gnutls_alert_send(session, GNUTLS_AL_WARNING,
GNUTLS_A_CLOSE_NOTIFY);
BYE_STATE = BYE_STATE1;
if (ret < 0) {
gnutls_assert();
return ret;
}
FALLTHROUGH;
case BYE_STATE2:
BYE_STATE = BYE_STATE2;
if (how == GNUTLS_SHUT_RDWR) {
do {
ret =
_gnutls_recv_int(session, GNUTLS_ALERT,
NULL, 0, NULL,
session->internals.
record_timeout_ms);
}
while (ret == GNUTLS_E_GOT_APPLICATION_DATA);
if (ret >= 0)
session->internals.may_not_read = 1;
if (ret < 0) {
gnutls_assert();
return ret;
}
}
BYE_STATE = BYE_STATE2;
break;
default:
gnutls_assert();
return GNUTLS_E_INTERNAL_ERROR;
}
BYE_STATE = BYE_STATE0;
session->internals.may_not_write = 1;
return 0;
}
inline static void session_unresumable(gnutls_session_t session)
{
session->internals.resumable = RESUME_FALSE;
}
/* returns 0 if session is valid
*/
inline static int session_is_valid(gnutls_session_t session)
{
if (session->internals.invalid_connection != 0)
return GNUTLS_E_INVALID_SESSION;
return 0;
}
/* Copies the record version into the headers. The
* version must have 2 bytes at least.
*/
inline static int
copy_record_version(gnutls_session_t session,
gnutls_handshake_description_t htype,
uint8_t version[2])
{
const version_entry_st *lver;
lver = get_version(session);
if (session->internals.initial_negotiation_completed ||
htype != GNUTLS_HANDSHAKE_CLIENT_HELLO ||
session->internals.default_record_version[0] == 0) {
if (unlikely(lver == NULL))
return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
if (lver->tls13_sem) {
version[0] = 0x03;
version[1] = 0x03;
} else {
version[0] = lver->major;
version[1] = lver->minor;
}
} else {
version[0] = session->internals.default_record_version[0];
version[1] = session->internals.default_record_version[1];
}
return 0;
}
/* Increments the sequence value
*/
inline static int
sequence_increment(gnutls_session_t session, uint64_t * value)
{
uint64_t snmax = UINT64_C(0xffffffffffffffff);
if (IS_DTLS(session)) {
uint64_t mask;
snmax = UINT64_C(0xffffffffffff);
mask = snmax;
if ((*value & mask) == snmax)
return -1;
*value = ((*value & mask) + 1) | (*value & ~mask);
} else {
if (*value == snmax)
return -1;
(*value)++;
}
return 0;
}
/* This function behaves exactly like write(). The only difference is
* that it accepts, the gnutls_session_t and the content_type_t of data to
* send (if called by the user the Content is specific)
* It is intended to transfer data, under the current session.
*
* @type: The content type to send
* @htype: If this is a handshake message then the handshake type
* @epoch_rel: %EPOCH_READ_* or %EPOCH_WRITE_*
* @data: the data to be sent
* @data_size: the size of the @data
* @min_pad: the minimum required padding
* @mflags: zero or %MBUFFER_FLUSH
*
* Oct 30 2001: Removed capability to send data more than MAX_RECORD_SIZE.
* This makes the function much easier to read, and more error resistant
* (there were cases were the old function could mess everything up).
* --nmav
*
* This function may accept a NULL pointer for data, and 0 for size, if
* and only if the previous send was interrupted for some reason.
*
*/
ssize_t
_gnutls_send_tlen_int(gnutls_session_t session, content_type_t type,
gnutls_handshake_description_t htype,
unsigned int epoch_rel, const void *_data,
size_t data_size, size_t min_pad,
unsigned int mflags)
{
mbuffer_st *bufel;
ssize_t cipher_size;
int retval, ret;
int send_data_size;
uint8_t *headers;
int header_size;
const uint8_t *data = _data;
record_parameters_st *record_params;
size_t max_send_size;
record_state_st *record_state;
const version_entry_st *vers = get_version(session);
ret = _gnutls_epoch_get(session, epoch_rel, &record_params);
if (ret < 0)
return gnutls_assert_val(ret);
/* Safeguard against processing data with an incomplete cipher state. */
if (!record_params->initialized)
return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
record_state = &record_params->write;
/* Do not allow null pointer if the send buffer is empty.
* If the previous send was interrupted then a null pointer is
* ok, and means to resume.
*/
if (session->internals.record_send_buffer.byte_length == 0 &&
(data_size == 0 && _data == NULL)) {
gnutls_assert();
return GNUTLS_E_INVALID_REQUEST;
}
if (type != GNUTLS_ALERT) /* alert messages are sent anyway */
if (session_is_valid(session)
|| session->internals.may_not_write != 0) {
gnutls_assert();
return GNUTLS_E_INVALID_SESSION;
}
max_send_size = max_record_send_size(session, record_params);
if (data_size > max_send_size) {
if (IS_DTLS(session))
return gnutls_assert_val(GNUTLS_E_LARGE_PACKET);
send_data_size = max_send_size;
} else
send_data_size = data_size;
/* Only encrypt if we don't have data to send
* from the previous run. - probably interrupted.
*/
if (mflags != 0
&& session->internals.record_send_buffer.byte_length > 0) {
ret = _gnutls_io_write_flush(session);
if (ret > 0)
cipher_size = ret;
else
cipher_size = 0;
retval = session->internals.record_send_buffer_user_size;
} else {
if (unlikely((send_data_size == 0 && min_pad == 0)))
return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
/* now proceed to packet encryption
*/
cipher_size = MAX_RECORD_SEND_SIZE(session);
bufel = _mbuffer_alloc_align16(cipher_size + CIPHER_SLACK_SIZE,
get_total_headers2(session, record_params));
if (bufel == NULL)
return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
headers = _mbuffer_get_uhead_ptr(bufel);
if (vers->tls13_sem && record_params->cipher->id != GNUTLS_CIPHER_NULL)
headers[0] = GNUTLS_APPLICATION_DATA;
else
headers[0] = type;
/* Use the default record version, if it is
* set. */
ret = copy_record_version(session, htype, &headers[1]);
if (ret < 0)
return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
/* Adjust header length and add sequence for DTLS */
if (IS_DTLS(session))
_gnutls_write_uint64(record_state->sequence_number, &headers[3]);
_gnutls_record_log
("REC[%p]: Preparing Packet %s(%d) with length: %d and min pad: %d\n",
session, _gnutls_packet2str(type), type,
(int) data_size, (int) min_pad);
header_size = RECORD_HEADER_SIZE(session);
_mbuffer_set_udata_size(bufel, cipher_size);
_mbuffer_set_uhead_size(bufel, header_size);
ret =
_gnutls_encrypt(session,
data, send_data_size, min_pad,
bufel, type, record_params);
if (ret <= 0) {
gnutls_assert();
if (ret == 0)
ret = GNUTLS_E_ENCRYPTION_FAILED;
gnutls_free(bufel);
return ret; /* error */
}
cipher_size = _mbuffer_get_udata_size(bufel);
retval = send_data_size;
session->internals.record_send_buffer_user_size =
send_data_size;
/* increase sequence number
*/
if (sequence_increment
(session, &record_state->sequence_number) != 0) {
session_invalidate(session);
gnutls_free(bufel);
return
gnutls_assert_val
(GNUTLS_E_RECORD_LIMIT_REACHED);
}
ret = _gnutls_io_write_buffered(session, bufel, mflags);
}
if (ret != cipher_size) {
/* If we have sent any data then just return
* the error value. Do not invalidate the session.
*/
if (ret < 0 && gnutls_error_is_fatal(ret) == 0)
return gnutls_assert_val(ret);
if (ret > 0)
ret = gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
session_unresumable(session);
session->internals.may_not_write = 1;
return gnutls_assert_val(ret);
}
session->internals.record_send_buffer_user_size = 0;
_gnutls_record_log
("REC[%p]: Sent Packet[%ld] %s(%d) in epoch %d and length: %d\n",
session, (unsigned long)(record_state->sequence_number),
_gnutls_packet2str(type), type, (int) record_params->epoch,
(int) cipher_size);
if (vers->tls13_sem && !(session->internals.flags & GNUTLS_NO_AUTO_REKEY) &&
!(record_params->cipher->flags & GNUTLS_CIPHER_FLAG_NO_REKEY)) {
if (unlikely((record_state->sequence_number & UINT64_C(0xffffff)) == UINT64_C(0xfffffd))) {
/* After we have sent 2^24 messages, mark the session
* as needing a key update. */
session->internals.rsend_state = RECORD_SEND_KEY_UPDATE_1;
}
}
return retval;
}
inline static int
check_recv_type(gnutls_session_t session, content_type_t recv_type)
{
switch (recv_type) {
case GNUTLS_CHANGE_CIPHER_SPEC:
case GNUTLS_ALERT:
case GNUTLS_HANDSHAKE:
case GNUTLS_HEARTBEAT:
case GNUTLS_APPLICATION_DATA:
return 0;
default:
gnutls_assert();
_gnutls_audit_log(session,
"Received record packet of unknown type %u\n",
(unsigned int) recv_type);
return GNUTLS_E_UNEXPECTED_PACKET;
}
}
/* Checks if there are pending data in the record buffers. If there are
* then it copies the data.
*/
static int
get_data_from_buffers(gnutls_session_t session, content_type_t type,
uint8_t * data, int data_size, void *seq)
{
if ((type == GNUTLS_APPLICATION_DATA ||
type == GNUTLS_HANDSHAKE || type == GNUTLS_CHANGE_CIPHER_SPEC)
&& _gnutls_record_buffer_get_size(session) > 0) {
int ret;
ret =
_gnutls_record_buffer_get(type, session, data,
data_size, seq);
if (ret < 0) {
if (IS_DTLS(session)) {
if (ret == GNUTLS_E_UNEXPECTED_PACKET) {
ret = GNUTLS_E_AGAIN;
}
}
gnutls_assert();
return ret;
}
return ret;
}
return 0;
}
/* Checks and retrieves any pending data in the application data record buffers.
*/
static int
get_packet_from_buffers(gnutls_session_t session, content_type_t type,
gnutls_packet_t *packet)
{
if (_gnutls_record_buffer_get_size(session) > 0) {
int ret;
ret =
_gnutls_record_buffer_get_packet(type, session, packet);
if (ret < 0) {
if (IS_DTLS(session)) {
if (ret == GNUTLS_E_UNEXPECTED_PACKET) {
ret = GNUTLS_E_AGAIN;
}
}
gnutls_assert();
return ret;
}
return ret;
}
*packet = NULL;
return 0;
}
/* Here we check if the advertized version is the one we
* negotiated in the handshake.
*/
inline static int
record_check_version(gnutls_session_t session,
gnutls_handshake_description_t htype,
uint8_t version[2])
{
const version_entry_st *vers = get_version(session);
int diff = 0;
if (vers->tls13_sem) {
/* TLS 1.3 requires version to be 0x0303 */
if (version[0] != 0x03 || version[1] != 0x03)
diff = 1;
} else {
if (vers->major != version[0] || vers->minor != version[1])
diff = 1;
}
if (!IS_DTLS(session)) {
if (htype == GNUTLS_HANDSHAKE_CLIENT_HELLO ||
htype == GNUTLS_HANDSHAKE_HELLO_RETRY_REQUEST ||
htype == GNUTLS_HANDSHAKE_SERVER_HELLO) {
if (version[0] != 3) {
gnutls_assert();
_gnutls_record_log
("REC[%p]: INVALID VERSION PACKET: (%d) %d.%d\n",
session, htype, version[0],
version[1]);
return GNUTLS_E_UNSUPPORTED_VERSION_PACKET;
}
} else if (diff != 0) {
/* Reject record packets that have a different version than the
* one negotiated. Note that this version is not protected by any
* mac. I don't really think that this check serves any purpose.
*/
gnutls_assert();
_gnutls_record_log
("REC[%p]: INVALID VERSION PACKET: (%d) %d.%d\n",
session, htype, version[0], version[1]);
return GNUTLS_E_UNSUPPORTED_VERSION_PACKET;
}
} else { /* DTLS */
/* In DTLS the only information we have here is whether we
* expect a handshake message or not.
*/
if (htype == (gnutls_handshake_description_t) - 1) {
if (diff) {
/* Reject record packets that have a different version than the
* one negotiated. Note that this version is not protected by any
* mac. I don't really think that this check serves any purpose.
*/
gnutls_assert();
_gnutls_record_log
("REC[%p]: INVALID VERSION PACKET: (%d) %d.%d\n",
session, htype, version[0],
version[1]);
return GNUTLS_E_UNSUPPORTED_VERSION_PACKET;
}
} else if (vers->id > GNUTLS_DTLS1_0 && version[0] > 254) {
gnutls_assert();
_gnutls_record_log
("REC[%p]: INVALID DTLS VERSION PACKET: (%d) %d.%d\n",
session, htype, version[0], version[1]);
return GNUTLS_E_UNSUPPORTED_VERSION_PACKET;
} else if (vers->id == GNUTLS_DTLS0_9 && version[0] > 1) {
gnutls_assert();
_gnutls_record_log
("REC[%p]: INVALID DTLS VERSION PACKET: (%d) %d.%d\n",
session, htype, version[0], version[1]);
return GNUTLS_E_UNSUPPORTED_VERSION_PACKET;
}
}
return 0;
}
static int
recv_hello_request(gnutls_session_t session, void *data,
uint32_t data_size)
{
uint8_t type;
if (session->security_parameters.entity == GNUTLS_SERVER)
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET);
if (data_size < 1)
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
if (session->internals.handshake_in_progress)
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET);
type = ((uint8_t *) data)[0];
if (type == GNUTLS_HANDSHAKE_HELLO_REQUEST) {
if (IS_DTLS(session))
session->internals.dtls.hsk_read_seq++;
if (session->internals.flags & GNUTLS_AUTO_REAUTH) {
session->internals.recv_state = RECV_STATE_REHANDSHAKE;
return GNUTLS_E_AGAIN;
} else {
return GNUTLS_E_REHANDSHAKE;
}
} else {
gnutls_assert();
return GNUTLS_E_UNEXPECTED_PACKET;
}
}
/* This function will check if the received record type is
* the one we actually expect and adds it to the proper
* buffer. The bufel will be deinitialized after calling
* this function, even if it fails.
*/
static int
record_add_to_buffers(gnutls_session_t session,
struct tls_record_st *recv, content_type_t type,
gnutls_handshake_description_t htype,
uint64_t seq, mbuffer_st * bufel)
{
int ret;
const version_entry_st *ver = get_version(session);
if ((recv->type == type)
&& (type == GNUTLS_APPLICATION_DATA ||
type == GNUTLS_CHANGE_CIPHER_SPEC ||
type == GNUTLS_HANDSHAKE)) {
if (bufel->msg.size == 0) {
if (type == GNUTLS_APPLICATION_DATA) {
/* this is needed to distinguish an empty
* message and EOF */
ret = GNUTLS_E_AGAIN;
goto cleanup;
} else {
ret =
gnutls_assert_val
(GNUTLS_E_UNEXPECTED_PACKET);
goto unexpected_packet;
}
}
/* application data cannot be inserted between (async) handshake
* messages */
if (type == GNUTLS_APPLICATION_DATA &&
(session->internals.handshake_recv_buffer_size != 0 ||
session->internals.handshake_header_recv_buffer.length != 0)) {
ret = gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET);
goto unexpected_packet;
}
_gnutls_record_buffer_put(session, type, seq, bufel);
/* if we received application data as expected then we
* deactivate the async timer */
_dtls_async_timer_delete(session);
} else {
/* if the expected type is different than the received
*/
switch (recv->type) {
case GNUTLS_ALERT:
if (bufel->msg.size < 2) {
ret =
gnutls_assert_val
(GNUTLS_E_UNEXPECTED_PACKET);
goto unexpected_packet;
}
_gnutls_record_log
("REC[%p]: Alert[%d|%d] - %s - was received\n",
session, bufel->msg.data[0],
bufel->msg.data[1],
gnutls_alert_get_name((int) bufel->msg.
data[1]));
if (!session->internals.initial_negotiation_completed &&
session->internals.handshake_in_progress && STATE == STATE0) { /* handshake hasn't started */
ret = gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET);
goto unexpected_packet;
}
session->internals.last_alert = bufel->msg.data[1];
/* if close notify is received and
* the alert is not fatal
*/
if (bufel->msg.data[1] == GNUTLS_A_CLOSE_NOTIFY
&& bufel->msg.data[0] != GNUTLS_AL_FATAL) {
/* If we have been expecting for an alert do
*/
session->internals.read_eof = 1;
ret = GNUTLS_E_SESSION_EOF;
goto cleanup;
} else {
/* if the alert is FATAL or WARNING
* return the appropriate message
*/
gnutls_assert();
ret = GNUTLS_E_WARNING_ALERT_RECEIVED;
if ((ver && ver->tls13_sem) || bufel->msg.data[0] == GNUTLS_AL_FATAL) {
session_unresumable(session);
session_invalidate(session);
ret =
gnutls_assert_val
(GNUTLS_E_FATAL_ALERT_RECEIVED);
}
goto cleanup;
}
break;
case GNUTLS_CHANGE_CIPHER_SPEC:
if (!(IS_DTLS(session))) {
ret = gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET);
goto cleanup;
}
_gnutls_record_buffer_put(session, recv->type, seq,
bufel);
break;
#ifdef ENABLE_HEARTBEAT
case GNUTLS_HEARTBEAT:
ret = _gnutls_heartbeat_handle(session, bufel);
goto cleanup;
#endif
case GNUTLS_APPLICATION_DATA:
if (session->internals.
initial_negotiation_completed == 0) {
ret =
gnutls_assert_val
(GNUTLS_E_UNEXPECTED_PACKET);
goto unexpected_packet;
}
/* In TLS1.3 post-handshake authentication allow application
* data error code. */
if ((ver && ver->tls13_sem) && type == GNUTLS_HANDSHAKE &&
htype == GNUTLS_HANDSHAKE_CERTIFICATE_PKT &&
session->internals.initial_negotiation_completed) {
_gnutls_record_buffer_put(session, recv->type,
seq, bufel);
return
gnutls_assert_val
(GNUTLS_E_GOT_APPLICATION_DATA);
}
/* The got_application data is only returned
* if expecting client hello (for rehandshake
* reasons). Otherwise it is an unexpected packet
*/
if (type == GNUTLS_ALERT
|| ((htype == GNUTLS_HANDSHAKE_SERVER_HELLO ||
htype == GNUTLS_HANDSHAKE_CLIENT_HELLO ||
htype == GNUTLS_HANDSHAKE_HELLO_RETRY_REQUEST)
&& type == GNUTLS_HANDSHAKE)) {
/* even if data is unexpected put it into the buffer */
_gnutls_record_buffer_put(session, recv->type,
seq, bufel);
return
gnutls_assert_val
(GNUTLS_E_GOT_APPLICATION_DATA);
} else {
ret =
gnutls_assert_val
(GNUTLS_E_UNEXPECTED_PACKET);
goto unexpected_packet;
}
break;
case GNUTLS_HANDSHAKE:
/* In DTLS we might receive a handshake replay from the peer to indicate
* the our last TLS handshake messages were not received.
*/
if (IS_DTLS(session)) {
if (type == GNUTLS_CHANGE_CIPHER_SPEC) {
ret =
gnutls_assert_val
(GNUTLS_E_UNEXPECTED_PACKET);
goto unexpected_packet;
}
if (_dtls_is_async(session)
&& _dtls_async_timer_active(session)) {
if (session->security_parameters.
entity == GNUTLS_SERVER
&& bufel->htype ==
GNUTLS_HANDSHAKE_CLIENT_HELLO)
{
/* client requested rehandshake. Delete the timer */
_dtls_async_timer_delete
(session);
} else {
session->internals.
recv_state =
RECV_STATE_DTLS_RETRANSMIT;
ret =
_dtls_retransmit
(session);
if (ret == 0) {
session->internals.
recv_state =
RECV_STATE_0;
ret =
gnutls_assert_val
(GNUTLS_E_AGAIN);
goto unexpected_packet;
}
goto cleanup;
}
}
}
/* retrieve async handshake messages */
if (ver && ver->tls13_sem) {
_gnutls_record_buffer_put(session, recv->type, seq, bufel);
ret = _gnutls13_recv_async_handshake(session);
if (ret < 0)
return gnutls_assert_val(ret);
/* bufel is now accounted */
return GNUTLS_E_AGAIN;
}
/* This is legal if HELLO_REQUEST is received - and we are a client.
* If we are a server, a client may initiate a renegotiation at any time.
*/
if (session->security_parameters.entity ==
GNUTLS_SERVER
&& session->internals.handshake_in_progress == 0
&& bufel->htype ==
GNUTLS_HANDSHAKE_CLIENT_HELLO) {
gnutls_assert();
_gnutls_record_buffer_put(session,
recv->type,
seq, bufel);
return GNUTLS_E_REHANDSHAKE;
}
/* If we are already in a handshake then a Hello
* Request is illegal. But here we don't really care
* since this message will never make it up here.
*/
/* So we accept it, if it is a Hello. If not, this will
* fail and trigger flight retransmissions after some time. */
ret =
recv_hello_request(session,
bufel->msg.data,
bufel->msg.size);
goto unexpected_packet;
default:
_gnutls_record_log
("REC[%p]: Received unexpected packet %d (%s) expecting %d (%s)\n",
session, recv->type,
_gnutls_packet2str(recv->type), type,
_gnutls_packet2str(type));
gnutls_assert();
ret = GNUTLS_E_UNEXPECTED_PACKET;
goto unexpected_packet;
}
}
return 0;
unexpected_packet:
if (IS_DTLS(session) && ret != GNUTLS_E_REHANDSHAKE) {
_mbuffer_xfree(&bufel);
RETURN_DTLS_EAGAIN_OR_TIMEOUT(session, ret);
}
cleanup:
_mbuffer_xfree(&bufel);
return ret;
}
/* Checks the record headers and returns the length, version and
* content type.
*/
static void
record_read_headers(gnutls_session_t session,
uint8_t headers[MAX_RECORD_HEADER_SIZE],
content_type_t type,
gnutls_handshake_description_t htype,
struct tls_record_st *record)
{
/* Read the first two bytes to determine if this is a
* version 2 message
*/
#ifdef ENABLE_SSL2
if (htype == GNUTLS_HANDSHAKE_CLIENT_HELLO
&& type == GNUTLS_HANDSHAKE && headers[0] > 127
&& !(IS_DTLS(session))) {
/* if msb set and expecting handshake message
* it should be SSL 2 hello
*/
record->version[0] = 3; /* assume SSL 3.0 */
record->version[1] = 0;
record->length = (((headers[0] & 0x7f) << 8)) | headers[1];
/* SSL 2.0 headers */
record->header_size = record->packet_size = 2;
record->type = GNUTLS_HANDSHAKE; /* we accept only v2 client hello
*/
/* in order to assist the handshake protocol.
* V2 compatibility is a mess.
*/
record->v2 = 1;
record->epoch = 0;
memset(&record->sequence, 0, sizeof(record->sequence));
_gnutls_record_log
("REC[%p]: SSL 2.0 %s packet received. Length: %d\n",
session, _gnutls_packet2str(record->type),
record->length);
} else
#endif
{
/* dtls version 1.0 and TLS version 1.x */
#ifdef ENABLE_SSL2
record->v2 = 0;
#endif
record->type = headers[0];
record->version[0] = headers[1];
record->version[1] = headers[2];
if (IS_DTLS(session)) {
record->sequence = _gnutls_read_uint64(&headers[3]);
record->length = _gnutls_read_uint16(&headers[11]);
record->epoch = record->sequence >> 48;
} else {
memset(&record->sequence, 0,
sizeof(record->sequence));
record->length = _gnutls_read_uint16(&headers[3]);
record->epoch = session->security_parameters.epoch_read;
}
_gnutls_record_log
("REC[%p]: SSL %d.%d %s packet received. Epoch %d, length: %d\n",
session, (int) record->version[0],
(int) record->version[1],
_gnutls_packet2str(record->type), (int) record->epoch,
record->length);
}
record->packet_size += record->length;
}
static int recv_headers(gnutls_session_t session,
record_parameters_st *record_params,
content_type_t type,
gnutls_handshake_description_t htype,
struct tls_record_st *record, unsigned int *ms)
{
int ret;
gnutls_datum_t raw; /* raw headers */
/* Read the headers.
*/
record->header_size = record->packet_size =
RECORD_HEADER_SIZE(session);
ret =
_gnutls_io_read_buffered(session, record->header_size, -1, ms);
if (ret != record->header_size) {
if (ret < 0 && gnutls_error_is_fatal(ret) == 0)
return ret;
if (ret > 0)
ret = GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
else if (ret == 0)
ret = GNUTLS_E_PREMATURE_TERMINATION;
return gnutls_assert_val(ret);
}
ret = _mbuffer_linearize_align16(&session->internals.record_recv_buffer,
get_total_headers2(session, record_params));
if (ret < 0)
return gnutls_assert_val(ret);
_mbuffer_head_get_first(&session->internals.record_recv_buffer,
&raw);
if (raw.size < RECORD_HEADER_SIZE(session))
return
gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
record_read_headers(session, raw.data, type, htype, record);
/* Check if the DTLS epoch is valid */
if (IS_DTLS(session)) {
if (_gnutls_epoch_is_valid(session, record->epoch) == 0) {
_gnutls_audit_log(session,
"Discarded message[%lu] with invalid epoch %u.\n",
(unsigned long)record->sequence,
(unsigned int) (record->sequence >> 48));
gnutls_assert();
/* doesn't matter, just a fatal error */
return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
}
}
/* Here we check if the Type of the received packet is
* ok.
*/
if ((ret = check_recv_type(session, record->type)) < 0)
return gnutls_assert_val(ret);
/* Here we check if the advertized version is the one we
* negotiated in the handshake.
*/
if ((ret =
record_check_version(session, htype, record->version)) < 0)
return gnutls_assert_val(ret);
if (record->length == 0 || record->length > max_record_recv_size(session)) {
_gnutls_audit_log
(session, "Received packet with illegal length: %u (max: %u)\n",
(unsigned int) record->length, (unsigned)max_record_recv_size(session));
if (record->length == 0) {
/* Empty, unencrypted records are always unexpected. */
if (record_params->cipher->id == GNUTLS_CIPHER_NULL)
return
gnutls_assert_val
(GNUTLS_E_UNEXPECTED_PACKET);
return gnutls_assert_val(GNUTLS_E_DECRYPTION_FAILED);
}
return
gnutls_assert_val(GNUTLS_E_RECORD_OVERFLOW);
}
_gnutls_record_log
("REC[%p]: Expected Packet %s(%d)\n", session,
_gnutls_packet2str(type), type);
_gnutls_record_log
("REC[%p]: Received Packet %s(%d) with length: %d\n", session,
_gnutls_packet2str(record->type), record->type,
record->length);
return 0;
}
/* @ms: is the number of milliseconds to wait for data. Use zero for indefinite.
*
* This will receive record layer packets and add them to
* application_data_buffer and handshake_data_buffer.
*
* If the htype is not -1 then handshake timeouts
* will be enforced.
*/
ssize_t
_gnutls_recv_in_buffers(gnutls_session_t session, content_type_t type,
gnutls_handshake_description_t htype,
unsigned int ms)
{
uint64_t packet_sequence;
gnutls_datum_t ciphertext;
mbuffer_st *bufel = NULL, *decrypted = NULL;
gnutls_datum_t t;
int ret;
unsigned int n_retries = 0;
record_parameters_st *record_params;
record_state_st *record_state;
struct tls_record_st record;
const version_entry_st *vers = get_version(session);
begin:
if (n_retries > DEFAULT_MAX_EMPTY_RECORDS) {
gnutls_assert();
return GNUTLS_E_TOO_MANY_EMPTY_PACKETS;
}
if (session->internals.read_eof != 0) {
/* if we have already read an EOF
*/
return 0;
} else if (session_is_valid(session) != 0
|| session->internals.may_not_read != 0)
return gnutls_assert_val(GNUTLS_E_INVALID_SESSION);
/* get the record state parameters */
ret =
_gnutls_epoch_get(session, EPOCH_READ_CURRENT, &record_params);
if (ret < 0)
return gnutls_assert_val(ret);
/* Safeguard against processing data with an incomplete cipher state. */
if (!record_params->initialized)
return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
record_state = &record_params->read;
/* receive headers */
ret = recv_headers(session, record_params, type, htype, &record, (!(session->internals.flags & GNUTLS_NONBLOCK))?&ms:0);
if (ret < 0) {
ret = gnutls_assert_val_fatal(ret);
goto recv_error;
}
if (IS_DTLS(session))
packet_sequence = record.sequence;
else
packet_sequence = record_state->sequence_number;
/* Read the packet data and insert it to record_recv_buffer.
*/
ret =
_gnutls_io_read_buffered(session, record.packet_size,
record.type, (!(session->internals.flags & GNUTLS_NONBLOCK))?&ms:0);
if (ret != record.packet_size) {
gnutls_assert();
goto recv_error;
}
/* ok now we are sure that we have read all the data - so
* move on !
*/
ret = _mbuffer_linearize_align16(&session->internals.record_recv_buffer,
get_total_headers2(session, record_params));
if (ret < 0)
return gnutls_assert_val(ret);
bufel =
_mbuffer_head_get_first(&session->internals.record_recv_buffer,
NULL);
if (bufel == NULL)
return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
if (vers && vers->tls13_sem && record.type == GNUTLS_CHANGE_CIPHER_SPEC) {
/* if the CCS has value other than 0x01, or arrives
* after Finished, abort the connection */
if (record.length != 1 ||
*((uint8_t *) _mbuffer_get_udata_ptr(bufel) +
record.header_size) != 0x01 ||
!session->internals.handshake_in_progress)
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET);
_gnutls_read_log("discarding change cipher spec in TLS1.3\n");
/* we use the same mechanism to retry as when
* receiving multiple empty TLS packets */
bufel =
_mbuffer_head_pop_first(&session->internals.
record_recv_buffer);
_mbuffer_xfree(&bufel);
n_retries++;
goto begin;
}
/* We allocate the maximum possible to allow few compressed bytes to expand to a
* full record. Moreover we add space for any pad and the MAC (in case
* they are encrypted).
*/
ret = max_decrypted_size(session) + MAX_PAD_SIZE + MAX_HASH_SIZE;
decrypted = _mbuffer_alloc_align16(ret, 0);
if (decrypted == NULL)
return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
_mbuffer_set_udata_size(decrypted, ret);
ciphertext.data =
(uint8_t *) _mbuffer_get_udata_ptr(bufel) + record.header_size;
ciphertext.size = record.length;
/* decrypt the data we got.
*/
t.data = _mbuffer_get_udata_ptr(decrypted);
t.size = _mbuffer_get_udata_size(decrypted);
ret =
_gnutls_decrypt(session, &ciphertext, &t,
&record.type, record_params, packet_sequence);
if (ret >= 0)
_mbuffer_set_udata_size(decrypted, ret);
_mbuffer_head_remove_bytes(&session->internals.record_recv_buffer,
record.header_size + record.length);
if (session->security_parameters.entity == GNUTLS_SERVER &&
session->internals.hsk_flags & HSK_EARLY_DATA_IN_FLIGHT) {
if (session->internals.hsk_flags & HSK_EARLY_DATA_ACCEPTED) {
if (ret < 0 ||
/* early data must always be encrypted, treat it
* as decryption failure if otherwise */
record_params->cipher->id == GNUTLS_CIPHER_NULL) {
_gnutls_record_log
("REC[%p]: failed to decrypt early data, in epoch %d\n",
session,
record_params->epoch);
ret = GNUTLS_E_DECRYPTION_FAILED;
goto sanity_check_error;
} else if (record.type == GNUTLS_APPLICATION_DATA) {
size_t decrypted_length =
_mbuffer_get_udata_size(decrypted);
_gnutls_record_log
("REC[%p]: decrypted early data with length: %d, in epoch %d\n",
session,
(int) decrypted_length,
record_params->epoch);
if (decrypted_length >
session->security_parameters.max_early_data_size -
session->internals.early_data_received) {
_gnutls_record_log
("REC[%p]: max_early_data_size exceeded\n",
session);
ret = GNUTLS_E_UNEXPECTED_PACKET;
goto sanity_check_error;
}
_mbuffer_enqueue(&session->internals.early_data_recv_buffer, decrypted);
session->internals.early_data_received +=
decrypted_length;
/* Increase sequence number. We do both for TLS and DTLS, since in
* DTLS we also rely on that number (roughly) since it may get reported
* to application via gnutls_record_get_state().
*/
if (sequence_increment(session, &record_state->sequence_number) != 0) {
session_invalidate(session);
gnutls_assert();
ret = GNUTLS_E_RECORD_LIMIT_REACHED;
goto sanity_check_error;
}
/* decrypted is now accounted */
return GNUTLS_E_AGAIN;
}
} else {
/* We do not accept early data: skip decryption
* failure up to max_early_data_size. Otherwise,
* if the record is properly decrypted, treat it as
* the start of client's second flight.
*/
if (record.type == GNUTLS_APPLICATION_DATA &&
(ret < 0 ||
/* early data must always be encrypted, treat it
* as decryption failure if otherwise */
record_params->cipher->id == GNUTLS_CIPHER_NULL)) {
if (record.length >
session->security_parameters.max_early_data_size -
session->internals.early_data_received) {
_gnutls_record_log
("REC[%p]: max_early_data_size exceeded\n",
session);
ret = GNUTLS_E_UNEXPECTED_PACKET;
goto sanity_check_error;
}
_gnutls_record_log("REC[%p]: Discarded early data[%lu] due to invalid decryption, length: %u\n",
session,
(unsigned long)packet_sequence,
(unsigned int)
record.length);
session->internals.early_data_received += record.length;
/* silently discard received data */
_mbuffer_xfree(&decrypted);
return gnutls_assert_val(GNUTLS_E_AGAIN);
} else {
session->internals.hsk_flags &= ~HSK_EARLY_DATA_IN_FLIGHT;
}
}
}
if (ret < 0) {
gnutls_assert();
_gnutls_audit_log(session,
"Discarded message[%lu] due to invalid decryption\n",
(unsigned long)packet_sequence);
goto sanity_check_error;
}
if (IS_DTLS(session)) {
/* check for duplicates. We check after the message
* is processed and authenticated to avoid someone
* messing with our windows. */
if (likely(!(session->internals.flags & GNUTLS_NO_REPLAY_PROTECTION))) {
ret = _dtls_record_check(record_params, packet_sequence);
if (ret < 0) {
_gnutls_record_log
("REC[%p]: Discarded duplicate message[%u.%lu]: %s\n",
session,
(unsigned int) (record.sequence >> 48),
(unsigned long) (packet_sequence),
_gnutls_packet2str(record.type));
goto sanity_check_error;
}
}
_gnutls_record_log
("REC[%p]: Decrypted Packet[%u.%lu] %s(%d) with length: %d\n",
session,
(unsigned int) (record.sequence >> 48),
(unsigned long) packet_sequence,
_gnutls_packet2str(record.type), record.type,
(int) _mbuffer_get_udata_size(decrypted));
/* store the last valid sequence number. We don't use that internally but
* callers of gnutls_record_get_state() could take advantage of it. */
record_state->sequence_number = record.sequence;
} else {
_gnutls_record_log
("REC[%p]: Decrypted Packet[%lu] %s(%d) with length: %d\n",
session,
(unsigned long) packet_sequence,
_gnutls_packet2str(record.type), record.type,
(int) _mbuffer_get_udata_size(decrypted));
}
/* Increase sequence number. We do both for TLS and DTLS, since in
* DTLS we also rely on that number (roughly) since it may get reported
* to application via gnutls_record_get_state().
*/
if (sequence_increment(session, &record_state->sequence_number) != 0) {
session_invalidate(session);
gnutls_assert();
ret = GNUTLS_E_RECORD_LIMIT_REACHED;
goto sanity_check_error;
}
/* (originally for) TLS 1.0 CBC protection.
* Actually this code is called if we just received
* an empty packet. An empty TLS packet is usually
* sent to protect some vulnerabilities in the CBC mode.
* In that case we go to the beginning and start reading
* the next packet.
*/
if (_mbuffer_get_udata_size(decrypted) == 0 &&
/* Under TLS 1.3, there are only AEAD ciphers and this
* logic is meaningless. Moreover, the implementation need
* to send correct alert upon receiving empty messages in
* certain occasions. Skip this and leave
* record_add_to_buffers() to handle the empty
* messages. */
!(vers && vers->tls13_sem)) {
_mbuffer_xfree(&decrypted);
n_retries++;
goto begin;
}
if (_mbuffer_get_udata_size(decrypted) > max_decrypted_size(session)) {
_gnutls_audit_log
(session, "Received packet with illegal length: %u\n",
(unsigned int) ret);
ret = gnutls_assert_val(GNUTLS_E_RECORD_OVERFLOW);
goto sanity_check_error;
}
#ifdef ENABLE_SSL2
if (record.v2) {
decrypted->htype = GNUTLS_HANDSHAKE_CLIENT_HELLO_V2;
} else
#endif
{
uint8_t *p = _mbuffer_get_udata_ptr(decrypted);
decrypted->htype = p[0];
}
ret =
record_add_to_buffers(session, &record, type, htype,
packet_sequence, decrypted);
/* decrypted is now either deinitialized or buffered somewhere else */
if (ret < 0)
return gnutls_assert_val(ret);
return ret;
discard:
session->internals.dtls.packets_dropped++;
/* discard the whole received fragment. */
bufel =
_mbuffer_head_pop_first(&session->internals.
record_recv_buffer);
_mbuffer_xfree(&bufel);
return gnutls_assert_val(GNUTLS_E_AGAIN);
sanity_check_error:
if (IS_DTLS(session)) {
session->internals.dtls.packets_dropped++;
ret = gnutls_assert_val(GNUTLS_E_AGAIN);
goto cleanup;
}
session_unresumable(session);
session_invalidate(session);
cleanup:
_mbuffer_xfree(&decrypted);
return ret;
recv_error:
if (ret < 0
&& (gnutls_error_is_fatal(ret) == 0
|| ret == GNUTLS_E_TIMEDOUT))
return ret;
if (type == GNUTLS_ALERT) { /* we were expecting close notify */
session_invalidate(session);
gnutls_assert();
return 0;
}
if (IS_DTLS(session) && (ret == GNUTLS_E_DECRYPTION_FAILED ||
ret == GNUTLS_E_UNSUPPORTED_VERSION_PACKET ||
ret == GNUTLS_E_UNEXPECTED_PACKET_LENGTH ||
ret == GNUTLS_E_RECORD_OVERFLOW ||
ret == GNUTLS_E_UNEXPECTED_PACKET ||
ret == GNUTLS_E_ERROR_IN_FINISHED_PACKET ||
ret == GNUTLS_E_UNEXPECTED_HANDSHAKE_PACKET)) {
goto discard;
}
session_invalidate(session);
session_unresumable(session);
if (ret == 0)
return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
else
return ret;
}
/* Returns a value greater than zero (>= 0) if buffers should be checked
* for data. */
static ssize_t
check_session_status(gnutls_session_t session, unsigned ms)
{
int ret;
if (session->internals.read_eof != 0) {
/* if we have already read an EOF
*/
return 0;
} else if (session_is_valid(session) != 0
|| session->internals.may_not_read != 0) {
gnutls_assert();
return GNUTLS_E_INVALID_SESSION;
}
switch (session->internals.recv_state) {
case RECV_STATE_REAUTH:
session->internals.recv_state = RECV_STATE_0;
ret = gnutls_reauth(session, 0);
if (ret < 0) {
/* a temp or fatal error, make sure we reset the state
* so we can resume on temp errors */
session->internals.recv_state = RECV_STATE_REAUTH;
return gnutls_assert_val(ret);
}
return 1;
case RECV_STATE_REHANDSHAKE:
session->internals.recv_state = RECV_STATE_0;
ret = gnutls_handshake(session);
if (ret < 0) {
/* a temp or fatal error, make sure we reset the state
* so we can resume on temp errors */
session->internals.recv_state = RECV_STATE_REHANDSHAKE;
return gnutls_assert_val(ret);
}
return 1;
case RECV_STATE_ASYNC_HANDSHAKE:
ret = _gnutls_recv_in_buffers(session, GNUTLS_HANDSHAKE, -1, ms);
if (ret < 0 && ret != GNUTLS_E_SESSION_EOF)
return gnutls_assert_val(ret);
ret = _gnutls13_recv_async_handshake(session);
if (ret < 0)
return gnutls_assert_val(ret);
return GNUTLS_E_AGAIN;
case RECV_STATE_EARLY_START_HANDLING:
case RECV_STATE_FALSE_START_HANDLING:
return 1;
case RECV_STATE_FALSE_START:
/* if false start is not complete we always expect for handshake packets
* prior to anything else. */
if (session->security_parameters.entity != GNUTLS_CLIENT ||
!(session->internals.flags & GNUTLS_ENABLE_FALSE_START))
return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
/* Attempt to complete handshake - we only need to receive */
session->internals.recv_state = RECV_STATE_FALSE_START_HANDLING;
ret = gnutls_handshake(session);
if (ret < 0) {
/* a temp or fatal error, make sure we reset the state
* so we can resume on temp errors */
session->internals.recv_state = RECV_STATE_FALSE_START;
return gnutls_assert_val(ret);
}
session->internals.recv_state = RECV_STATE_0;
return 1;
case RECV_STATE_EARLY_START:
/* if early start is not complete we always expect for handshake packets
* prior to anything else. */
if (session->security_parameters.entity != GNUTLS_SERVER ||
!(session->internals.flags & GNUTLS_ENABLE_EARLY_START))
return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
/* Attempt to complete handshake - we only need to receive */
session->internals.recv_state = RECV_STATE_EARLY_START_HANDLING;
ret = gnutls_handshake(session);
if (ret < 0) {
/* a temp or fatal error, make sure we reset the state
* so we can resume on temp errors */
session->internals.recv_state = RECV_STATE_EARLY_START;
return gnutls_assert_val(ret);
}
session->internals.recv_state = RECV_STATE_0;
return 1;
case RECV_STATE_DTLS_RETRANSMIT:
ret = _dtls_retransmit(session);
if (ret < 0)
return gnutls_assert_val(ret);
session->internals.recv_state = RECV_STATE_0;
FALLTHROUGH;
case RECV_STATE_0:
_dtls_async_timer_check(session);
return 1;
default:
return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
}
}
/* This function behaves exactly like read(). The only difference is
* that it accepts the gnutls_session_t and the content_type_t of data to
* receive (if called by the user the Content is Userdata only)
* It is intended to receive data, under the current session.
*/
ssize_t
_gnutls_recv_int(gnutls_session_t session, content_type_t type,
uint8_t * data, size_t data_size, void *seq,
unsigned int ms)
{
int ret;
if ((type != GNUTLS_ALERT && type != GNUTLS_HEARTBEAT)
&& (data_size == 0 || data == NULL))
return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
ret = check_session_status(session, ms);
if (ret <= 0)
return ret;
/* If we have enough data in the cache do not bother receiving
* a new packet. (in order to flush the cache)
*/
ret = get_data_from_buffers(session, type, data, data_size, seq);
if (ret != 0)
return ret;
ret = _gnutls_recv_in_buffers(session, type, -1, ms);
if (ret < 0 && ret != GNUTLS_E_SESSION_EOF)
return gnutls_assert_val(ret);
return get_data_from_buffers(session, type, data, data_size, seq);
}
/**
* gnutls_packet_get:
* @packet: is a #gnutls_packet_t type.
* @data: will contain the data present in the @packet structure (may be %NULL)
* @sequence: the 8-bytes of the packet sequence number (may be %NULL)
*
* This function returns the data and sequence number associated with
* the received packet.
*
* Since: 3.3.5
**/
void gnutls_packet_get(gnutls_packet_t packet, gnutls_datum_t *data, unsigned char *sequence)
{
if (unlikely(packet == NULL)) {
gnutls_assert();
if (data) {
data->data = NULL;
data->size = 0;
return;
}
}
assert(packet != NULL);
if (sequence) {
_gnutls_write_uint64(packet->record_sequence, sequence);
}
if (data) {
data->size = packet->msg.size - packet->mark;
data->data = packet->msg.data + packet->mark;
}
}
/**
* gnutls_packet_deinit:
* @packet: is a pointer to a #gnutls_packet_st structure.
*
* This function will deinitialize all data associated with
* the received packet.
*
* Since: 3.3.5
**/
void gnutls_packet_deinit(gnutls_packet_t packet)
{
gnutls_free(packet);
}
/**
* gnutls_record_discard_queued:
* @session: is a #gnutls_session_t type.
*
* This function discards all queued to be sent packets in a DTLS session.
* These are the packets queued after an interrupted gnutls_record_send().
*
* This function can only be used with transports where send() is
* an all-or-nothing operation (e.g., UDP). When partial writes are allowed
* this function will cause session errors.
*
* Returns: The number of bytes discarded.
*
* Since: 3.4.0
**/
size_t
gnutls_record_discard_queued(gnutls_session_t session)
{
size_t ret = session->internals.record_send_buffer.byte_length;
_mbuffer_head_clear(&session->internals.record_send_buffer);
return ret;
}
/**
* gnutls_record_recv_packet:
* @session: is a #gnutls_session_t type.
* @packet: the structure that will hold the packet data
*
* This is a lower-level function than gnutls_record_recv() and allows
* to directly receive the whole decrypted packet. That avoids a
* memory copy, and is intended to be used by applications seeking high
* performance.
*
* The received packet is accessed using gnutls_packet_get() and
* must be deinitialized using gnutls_packet_deinit(). The returned
* packet will be %NULL if the return value is zero (EOF).
*
* Returns: The number of bytes received and zero on EOF (for stream
* connections). A negative error code is returned in case of an error.
*
* Since: 3.3.5
**/
ssize_t
gnutls_record_recv_packet(gnutls_session_t session,
gnutls_packet_t *packet)
{
int ret;
if (packet == NULL)
return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
ret = check_session_status(session, session->internals.record_timeout_ms);
if (ret <= 0)
return ret;
ret = get_packet_from_buffers(session, GNUTLS_APPLICATION_DATA, packet);
if (ret != 0)
return ret;
ret = _gnutls_recv_in_buffers(session, GNUTLS_APPLICATION_DATA, -1,
session->internals.record_timeout_ms);
if (ret < 0 && ret != GNUTLS_E_SESSION_EOF)
return gnutls_assert_val(ret);
return get_packet_from_buffers(session, GNUTLS_APPLICATION_DATA, packet);
}
static
ssize_t append_data_to_corked(gnutls_session_t session, const void *data, size_t data_size)
{
int ret;
if (IS_DTLS(session)) {
if (data_size + session->internals.record_presend_buffer.length >
gnutls_dtls_get_data_mtu(session)) {
return gnutls_assert_val(GNUTLS_E_LARGE_PACKET);
}
}
ret =
_gnutls_buffer_append_data(&session->internals.
record_presend_buffer, data,
data_size);
if (ret < 0)
return gnutls_assert_val(ret);
return data_size;
}
/**
* gnutls_record_send:
* @session: is a #gnutls_session_t type.
* @data: contains the data to send
* @data_size: is the length of the data
*
* This function has the similar semantics with send(). The only
* difference is that it accepts a GnuTLS session, and uses different
* error codes.
* Note that if the send buffer is full, send() will block this
* function. See the send() documentation for more information.
*
* You can replace the default push function which is send(), by using
* gnutls_transport_set_push_function().
*
* If the EINTR is returned by the internal push function
* then %GNUTLS_E_INTERRUPTED will be returned. If
* %GNUTLS_E_INTERRUPTED or %GNUTLS_E_AGAIN is returned, you must
* call this function again with the exact same parameters, or provide a
* %NULL pointer for @data and 0 for @data_size, in order to write the
* same data as before. If you wish to discard the previous data instead
* of retrying, you must call gnutls_record_discard_queued() before
* calling this function with different parameters. Note that the latter
* works only on special transports (e.g., UDP).
* cf. gnutls_record_get_direction().
*
* Note that in DTLS this function will return the %GNUTLS_E_LARGE_PACKET
* error code if the send data exceed the data MTU value - as returned
* by gnutls_dtls_get_data_mtu(). The errno value EMSGSIZE
* also maps to %GNUTLS_E_LARGE_PACKET.
* Note that since 3.2.13 this function can be called under cork in DTLS
* mode, and will refuse to send data over the MTU size by returning
* %GNUTLS_E_LARGE_PACKET.
*
* Returns: The number of bytes sent, or a negative error code. The
* number of bytes sent might be less than @data_size. The maximum
* number of bytes this function can send in a single call depends
* on the negotiated maximum record size.
**/
ssize_t
gnutls_record_send(gnutls_session_t session, const void *data,
size_t data_size)
{
return gnutls_record_send2(session, data, data_size, 0, 0);
}
/**
* gnutls_record_send2:
* @session: is a #gnutls_session_t type.
* @data: contains the data to send
* @data_size: is the length of the data
* @pad: padding to be added to the record
* @flags: must be zero
*
* This function is identical to gnutls_record_send() except that it
* takes an extra argument to specify padding to be added the record.
* To determine the maximum size of padding, use
* gnutls_record_get_max_size() and gnutls_record_overhead_size().
*
* Note that in order for GnuTLS to provide constant time processing
* of padding and data in TLS1.3, the flag %GNUTLS_SAFE_PADDING_CHECK
* must be used in gnutls_init().
*
* Returns: The number of bytes sent, or a negative error code. The
* number of bytes sent might be less than @data_size. The maximum
* number of bytes this function can send in a single call depends
* on the negotiated maximum record size.
*
* Since: 3.6.3
**/
ssize_t
gnutls_record_send2(gnutls_session_t session, const void *data,
size_t data_size, size_t pad, unsigned flags)
{
const version_entry_st *vers = get_version(session);
size_t max_pad = 0;
int ret;
if (unlikely(!session->internals.initial_negotiation_completed)) {
/* this is to protect buggy applications from sending unencrypted
* data. We allow sending however, if we are in false or early start
* handshake state. */
gnutls_mutex_lock(&session->internals.post_negotiation_lock);
/* we intentionally re-check the initial_negotation_completed variable
* to avoid locking during normal operation of gnutls_record_send2() */
if (!session->internals.initial_negotiation_completed &&
session->internals.recv_state != RECV_STATE_FALSE_START &&
session->internals.recv_state != RECV_STATE_FALSE_START_HANDLING &&
session->internals.recv_state != RECV_STATE_EARLY_START &&
session->internals.recv_state != RECV_STATE_EARLY_START_HANDLING &&
!(session->internals.hsk_flags & HSK_EARLY_DATA_IN_FLIGHT)) {
gnutls_mutex_unlock(&session->internals.post_negotiation_lock);
return gnutls_assert_val(GNUTLS_E_UNAVAILABLE_DURING_HANDSHAKE);
}
gnutls_mutex_unlock(&session->internals.post_negotiation_lock);
}
if (unlikely(!vers))
return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
if (vers->tls13_sem)
max_pad = gnutls_record_get_max_size(session) - gnutls_record_overhead_size(session);
if (pad > max_pad)
return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
switch(session->internals.rsend_state) {
case RECORD_SEND_NORMAL:
return _gnutls_send_tlen_int(session, GNUTLS_APPLICATION_DATA,
-1, EPOCH_WRITE_CURRENT, data,
data_size, pad, MBUFFER_FLUSH);
case RECORD_SEND_CORKED:
case RECORD_SEND_CORKED_TO_KU:
return append_data_to_corked(session, data, data_size);
case RECORD_SEND_KEY_UPDATE_1:
_gnutls_buffer_reset(&session->internals.record_key_update_buffer);
ret = _gnutls_buffer_append_data(&session->internals.record_key_update_buffer,
data, data_size);
if (ret < 0)
return gnutls_assert_val(ret);
session->internals.rsend_state = RECORD_SEND_KEY_UPDATE_2;
FALLTHROUGH;
case RECORD_SEND_KEY_UPDATE_2:
ret = gnutls_session_key_update(session, 0);
if (ret < 0)
return gnutls_assert_val(ret);
session->internals.rsend_state = RECORD_SEND_KEY_UPDATE_3;
FALLTHROUGH;
case RECORD_SEND_KEY_UPDATE_3:
ret = _gnutls_send_int(session, GNUTLS_APPLICATION_DATA,
-1, EPOCH_WRITE_CURRENT,
session->internals.record_key_update_buffer.data,
session->internals.record_key_update_buffer.length,
MBUFFER_FLUSH);
_gnutls_buffer_clear(&session->internals.record_key_update_buffer);
session->internals.rsend_state = RECORD_SEND_NORMAL;
if (ret < 0)
gnutls_assert();
return ret;
default:
return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
}
}
/**
* gnutls_record_send_early_data:
* @session: is a #gnutls_session_t type.
* @data: contains the data to send
* @data_size: is the length of the data
*
* This function can be used by a client to send data early in the
* handshake processes when resuming a session. This is used to
* implement a zero-roundtrip (0-RTT) mode. It has the same semantics
* as gnutls_record_send().
*
* There may be a limit to the amount of data sent as early data. Use
* gnutls_record_get_max_early_data_size() to check the limit. If the
* limit exceeds, this function returns
* %GNUTLS_E_RECORD_LIMIT_REACHED.
*
* Returns: The number of bytes sent, or a negative error code. The
* number of bytes sent might be less than @data_size. The maximum
* number of bytes this function can send in a single call depends
* on the negotiated maximum record size.
*
* Since: 3.6.5
**/
ssize_t gnutls_record_send_early_data(gnutls_session_t session,
const void *data,
size_t data_size)
{
int ret;
if (session->security_parameters.entity != GNUTLS_CLIENT)
return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
if (xsum(session->internals.
early_data_presend_buffer.length,
data_size) >
session->security_parameters.max_early_data_size)
return gnutls_assert_val(GNUTLS_E_RECORD_LIMIT_REACHED);
ret =
_gnutls_buffer_append_data(&session->internals.
early_data_presend_buffer, data,
data_size);
if (ret < 0)
return gnutls_assert_val(ret);
return ret;
}
/**
* gnutls_record_recv_early_data:
* @session: is a #gnutls_session_t type.
* @data: the buffer that the data will be read into
* @data_size: the number of requested bytes
*
* This function can be used by a searver to retrieve data sent early
* in the handshake processes when resuming a session. This is used
* to implement a zero-roundtrip (0-RTT) mode. It has the same
* semantics as gnutls_record_recv().
*
* This function can be called either in a handshake hook, or after
* the handshake is complete.
*
* Returns: The number of bytes received and zero when early data
* reading is complete. A negative error code is returned in case of
* an error. If no early data is received during the handshake, this
* function returns %GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE. The
* number of bytes received might be less than the requested
* @data_size.
*
* Since: 3.6.5
**/
ssize_t
gnutls_record_recv_early_data(gnutls_session_t session, void *data, size_t data_size)
{
mbuffer_st *bufel;
gnutls_datum_t msg;
size_t length;
if (session->security_parameters.entity != GNUTLS_SERVER)
return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
bufel = _mbuffer_head_get_first(&session->internals.early_data_recv_buffer,
&msg);
if (bufel == NULL)
return
gnutls_assert_val
(GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE);
length = MIN(msg.size, data_size);
memcpy(data, msg.data, length);
_mbuffer_head_remove_bytes(&session->internals.early_data_recv_buffer,
length);
return length;
}
/**
* gnutls_record_cork:
* @session: is a #gnutls_session_t type.
*
* If called, gnutls_record_send() will no longer send any records.
* Any sent records will be cached until gnutls_record_uncork() is called.
*
* This function is safe to use with DTLS after GnuTLS 3.3.0.
*
* Since: 3.1.9
**/
void gnutls_record_cork(gnutls_session_t session)
{
session->internals.rsend_state = RECORD_SEND_CORKED;
}
/**
* gnutls_record_uncork:
* @session: is a #gnutls_session_t type.
* @flags: Could be zero or %GNUTLS_RECORD_WAIT
*
* This resets the effect of gnutls_record_cork(), and flushes any pending
* data. If the %GNUTLS_RECORD_WAIT flag is specified then this
* function will block until the data is sent or a fatal error
* occurs (i.e., the function will retry on %GNUTLS_E_AGAIN and
* %GNUTLS_E_INTERRUPTED).
*
* If the flag %GNUTLS_RECORD_WAIT is not specified and the function
* is interrupted then the %GNUTLS_E_AGAIN or %GNUTLS_E_INTERRUPTED
* errors will be returned. To obtain the data left in the corked
* buffer use gnutls_record_check_corked().
*
* Returns: On success the number of transmitted data is returned, or
* otherwise a negative error code.
*
* Since: 3.1.9
**/
int gnutls_record_uncork(gnutls_session_t session, unsigned int flags)
{
int ret;
ssize_t total = 0;
record_send_state_t orig_state = session->internals.rsend_state;
if (orig_state == RECORD_SEND_CORKED)
session->internals.rsend_state = RECORD_SEND_NORMAL;
else if (orig_state == RECORD_SEND_CORKED_TO_KU)
session->internals.rsend_state = RECORD_SEND_KEY_UPDATE_1;
else
return 0; /* nothing to be done */
while (session->internals.record_presend_buffer.length > 0) {
if (flags == GNUTLS_RECORD_WAIT) {
do {
ret =
gnutls_record_send(session,
session->internals.
record_presend_buffer.
data,
session->internals.
record_presend_buffer.
length);
}
while (ret < 0 && (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED));
} else {
ret =
gnutls_record_send(session,
session->internals.
record_presend_buffer.data,
session->internals.
record_presend_buffer.
length);
}
if (ret < 0)
goto fail;
session->internals.record_presend_buffer.data += ret;
session->internals.record_presend_buffer.length -= ret;
total += ret;
}
return total;
fail:
session->internals.rsend_state = orig_state;
return ret;
}
/**
* gnutls_record_recv:
* @session: is a #gnutls_session_t type.
* @data: the buffer that the data will be read into
* @data_size: the number of requested bytes
*
* This function has the similar semantics with recv(). The only
* difference is that it accepts a GnuTLS session, and uses different
* error codes.
* In the special case that the peer requests a renegotiation, the
* caller will receive an error code of %GNUTLS_E_REHANDSHAKE. In case
* of a client, this message may be simply ignored, replied with an alert
* %GNUTLS_A_NO_RENEGOTIATION, or replied with a new handshake,
* depending on the client's will. A server receiving this error code
* can only initiate a new handshake or terminate the session.
*
* If %EINTR is returned by the internal pull function (the default
* is recv()) then %GNUTLS_E_INTERRUPTED will be returned. If
* %GNUTLS_E_INTERRUPTED or %GNUTLS_E_AGAIN is returned, you must
* call this function again to get the data. See also
* gnutls_record_get_direction().
*
* Returns: The number of bytes received and zero on EOF (for stream
* connections). A negative error code is returned in case of an error.
* The number of bytes received might be less than the requested @data_size.
**/
ssize_t
gnutls_record_recv(gnutls_session_t session, void *data, size_t data_size)
{
if (unlikely(!session->internals.initial_negotiation_completed)) {
/* this is to protect buggy applications from sending unencrypted
* data. We allow sending however, if we are in false start handshake
* state. */
if (session->internals.recv_state != RECV_STATE_FALSE_START &&
session->internals.recv_state != RECV_STATE_EARLY_START)
return gnutls_assert_val(GNUTLS_E_UNAVAILABLE_DURING_HANDSHAKE);
}
return _gnutls_recv_int(session, GNUTLS_APPLICATION_DATA,
data, data_size, NULL,
session->internals.record_timeout_ms);
}
/**
* gnutls_record_recv_seq:
* @session: is a #gnutls_session_t type.
* @data: the buffer that the data will be read into
* @data_size: the number of requested bytes
* @seq: is the packet's 64-bit sequence number. Should have space for 8 bytes.
*
* This function is the same as gnutls_record_recv(), except that
* it returns in addition to data, the sequence number of the data.
* This is useful in DTLS where record packets might be received
* out-of-order. The returned 8-byte sequence number is an
* integer in big-endian format and should be
* treated as a unique message identification.
*
* Returns: The number of bytes received and zero on EOF. A negative
* error code is returned in case of an error. The number of bytes
* received might be less than @data_size.
*
* Since: 3.0
**/
ssize_t
gnutls_record_recv_seq(gnutls_session_t session, void *data,
size_t data_size, unsigned char *seq)
{
return _gnutls_recv_int(session, GNUTLS_APPLICATION_DATA,
data, data_size, seq,
session->internals.record_timeout_ms);
}
/**
* gnutls_record_set_timeout:
* @session: is a #gnutls_session_t type.
* @ms: is a timeout value in milliseconds
*
* This function sets the receive timeout for the record layer
* to the provided value. Use an @ms value of zero to disable
* timeout (the default), or %GNUTLS_INDEFINITE_TIMEOUT, to
* set an indefinite timeout.
*
* This function requires to set a pull timeout callback. See
* gnutls_transport_set_pull_timeout_function().
*
* Since: 3.1.7
**/
void gnutls_record_set_timeout(gnutls_session_t session, unsigned int ms)
{
session->internals.record_timeout_ms = ms;
}