/* returns ciphertext which contains the headers too. This also
* calculates the size in the header field.
*
*/
int
_gnutls_encrypt(gnutls_session_t session,
const uint8_t *data, size_t data_size,
size_t min_pad,
mbuffer_st *bufel,
content_type_t type, record_parameters_st *params)
{
gnutls_datum_t plaintext;
const version_entry_st *vers = get_version(session);
int ret;
plaintext.data = (uint8_t *) data;
plaintext.size = data_size;
if (vers && vers->tls13_sem) {
/* it fills the header, as it is included in the authenticated
* data of the AEAD cipher. */
ret =
encrypt_packet_tls13(session,
_mbuffer_get_udata_ptr(bufel),
_mbuffer_get_udata_size(bufel),
&plaintext, min_pad, type,
params);
if (ret < 0)
return gnutls_assert_val(ret);
} else {
ret =
encrypt_packet(session,
_mbuffer_get_udata_ptr(bufel),
_mbuffer_get_udata_size
(bufel), &plaintext, min_pad, type,
params);
if (ret < 0)
return gnutls_assert_val(ret);
}
if (IS_DTLS(session))
_gnutls_write_uint16(ret,
((uint8_t *)
_mbuffer_get_uhead_ptr(bufel)) + 11);
else
_gnutls_write_uint16(ret,
((uint8_t *)
_mbuffer_get_uhead_ptr(bufel)) + 3);
_mbuffer_set_udata_size(bufel, ret);
_mbuffer_set_uhead_size(bufel, 0);
return _mbuffer_get_udata_size(bufel);
}
static int
parse_handshake_header(gnutls_session_t session, mbuffer_st * bufel,
handshake_buffer_st * hsk)
{
uint8_t *dataptr = NULL; /* for realloc */
size_t handshake_header_size =
HANDSHAKE_HEADER_SIZE(session), data_size, frag_size;
/* Note: SSL2_HEADERS == 1 */
if (_mbuffer_get_udata_size(bufel) < handshake_header_size)
return
gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
dataptr = _mbuffer_get_udata_ptr(bufel);
/* if reading a client hello of SSLv2 */
#ifdef ENABLE_SSL2
if (unlikely
(!IS_DTLS(session)
&& bufel->htype == GNUTLS_HANDSHAKE_CLIENT_HELLO_V2)) {
handshake_header_size = SSL2_HEADERS; /* we've already read one byte */
frag_size = _mbuffer_get_udata_size(bufel) - handshake_header_size; /* we've read the first byte */
if (dataptr[0] != GNUTLS_HANDSHAKE_CLIENT_HELLO)
return
gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET);
hsk->rtype = hsk->htype = GNUTLS_HANDSHAKE_CLIENT_HELLO_V2;
hsk->sequence = 0;
hsk->start_offset = 0;
hsk->length = frag_size;
} else
#endif
{ /* TLS or DTLS handshake headers */
hsk->rtype = hsk->htype = dataptr[0];
/* we do not use DECR_LEN because we know
* that the packet has enough data.
*/
hsk->length = _gnutls_read_uint24(&dataptr[1]);
if (IS_DTLS(session)) {
hsk->sequence = _gnutls_read_uint16(&dataptr[4]);
hsk->start_offset =
_gnutls_read_uint24(&dataptr[6]);
frag_size =
_gnutls_read_uint24(&dataptr[9]);
} else {
hsk->sequence = 0;
hsk->start_offset = 0;
frag_size =
MIN((_mbuffer_get_udata_size(bufel) -
handshake_header_size), hsk->length);
}
/* TLS1.3: distinguish server hello versus hello retry request.
* The epitome of slick protocol design. */
if (hsk->htype == GNUTLS_HANDSHAKE_SERVER_HELLO && hsk->start_offset == 0 && !IS_DTLS(session)) {
if (_mbuffer_get_udata_size(bufel) > handshake_header_size+2+GNUTLS_RANDOM_SIZE &&
memcmp(dataptr+handshake_header_size+2, HRR_RANDOM, GNUTLS_RANDOM_SIZE) == 0) {
hsk->htype = GNUTLS_HANDSHAKE_HELLO_RETRY_REQUEST;
}
}
}
data_size = _mbuffer_get_udata_size(bufel) - handshake_header_size;
if (frag_size > 0)
hsk->end_offset = hsk->start_offset + frag_size - 1;
else
hsk->end_offset = 0;
_gnutls_handshake_log
("HSK[%p]: %s (%u) was received. Length %d[%d], frag offset %d, frag length: %d, sequence: %d\n",
session, _gnutls_handshake2str(hsk->htype),
(unsigned) hsk->htype, (int) hsk->length, (int) data_size,
hsk->start_offset, (int) frag_size,
(int) hsk->sequence);
hsk->header_size = handshake_header_size;
memcpy(hsk->header, _mbuffer_get_udata_ptr(bufel),
handshake_header_size);
if (hsk->length > 0 && (frag_size > data_size ||
(frag_size > 0 &&
hsk->end_offset >= hsk->length))) {
return
gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
}
else if (hsk->length == 0 && hsk->end_offset != 0
&& hsk->start_offset != 0)
return
gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
return handshake_header_size;
}
/* This is a receive function for the gnutls handshake
* protocol. Makes sure that we have received all data.
*
* htype is the next handshake packet expected.
*/
int _gnutls_parse_record_buffered_msgs(gnutls_session_t session)
{
gnutls_datum_t msg;
mbuffer_st *bufel = NULL, *prev = NULL;
int ret;
size_t data_size;
handshake_buffer_st *recv_buf =
session->internals.handshake_recv_buffer;
bufel =
_mbuffer_head_get_first(&session->internals.record_buffer,
&msg);
if (bufel == NULL)
return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;
if (!IS_DTLS(session)) {
ssize_t append, header_size;
do {
if (bufel->type != GNUTLS_HANDSHAKE)
return
gnutls_assert_val
(GNUTLS_E_UNEXPECTED_PACKET);
if (unlikely
(session->internals.handshake_recv_buffer_size == 0 &&
msg.size < HANDSHAKE_HEADER_SIZE(session) &&
session->internals.handshake_header_recv_buffer.byte_length <
HANDSHAKE_HEADER_SIZE(session) - msg.size)) {
bufel = _mbuffer_head_pop_first(&session->internals.record_buffer);
_mbuffer_enqueue(&session->internals.handshake_header_recv_buffer,
bufel);
break;
} else if (session->internals.handshake_recv_buffer_size >
0 && recv_buf[0].length > recv_buf[0].data.length) {
/* this is the rest of a previous message */
append = MIN(msg.size,
recv_buf[0].length -
recv_buf[0].data.length);
ret =
_gnutls_buffer_append_data(&recv_buf
[0].data,
msg.data,
append);
if (ret < 0)
return gnutls_assert_val(ret);
_mbuffer_head_remove_bytes(&session->
internals.
record_buffer,
append);
} else { /* received new message */
if (unlikely
(session->internals.
handshake_header_recv_buffer.length > 0)) {
bufel = _mbuffer_head_pop_first(&session->internals.
record_buffer);
_mbuffer_enqueue(&session->internals.
handshake_header_recv_buffer,
bufel);
ret = _mbuffer_linearize_align16(&session->internals.
handshake_header_recv_buffer,
get_total_headers(session));
if (ret < 0)
return gnutls_assert_val(ret);
bufel = _mbuffer_head_pop_first(&session->internals.
handshake_header_recv_buffer);
_mbuffer_head_push_first(&session->internals.
record_buffer,
bufel);
}
ret =
parse_handshake_header(session, bufel,
&recv_buf[0]);
if (ret < 0)
return gnutls_assert_val(ret);
header_size = ret;
session->internals.
handshake_recv_buffer_size = 1;
_mbuffer_set_uhead_size(bufel,
header_size);
data_size =
MIN(recv_buf[0].length,
_mbuffer_get_udata_size(bufel));
ret =
_gnutls_buffer_append_data(&recv_buf
[0].data,
_mbuffer_get_udata_ptr
(bufel),
data_size);
if (ret < 0)
return gnutls_assert_val(ret);
_mbuffer_set_uhead_size(bufel, 0);
_mbuffer_head_remove_bytes(&session->
internals.
record_buffer,
data_size +
header_size);
}
/* if packet is complete then return it
*/
if (recv_buf[0].length == recv_buf[0].data.length) {
return 0;
}
bufel =
_mbuffer_head_get_first(&session->internals.
record_buffer, &msg);
}
while (bufel != NULL);
/* if we are here it means that the received packets were not
* enough to complete the handshake packet.
*/
return gnutls_assert_val(GNUTLS_E_AGAIN);
} else { /* DTLS */
handshake_buffer_st tmp;
do {
/* we now
* 0. parse headers
* 1. insert to handshake_recv_buffer
* 2. sort handshake_recv_buffer on sequence numbers
* 3. return first packet if completed or GNUTLS_E_AGAIN.
*/
do {
if (bufel->type != GNUTLS_HANDSHAKE) {
gnutls_assert();
goto next; /* ignore packet */
}
_gnutls_handshake_buffer_init(&tmp);
ret =
parse_handshake_header(session, bufel,
&tmp);
if (ret < 0) {
gnutls_assert();
_gnutls_audit_log(session,
"Invalid handshake packet headers. Discarding.\n");
break;
}
_mbuffer_consume(&session->internals.
record_buffer, bufel,
ret);
data_size =
MIN(tmp.length,
tmp.end_offset - tmp.start_offset +
1);
ret =
_gnutls_buffer_append_data(&tmp.data,
_mbuffer_get_udata_ptr
(bufel),
data_size);
if (ret < 0)
return gnutls_assert_val(ret);
_mbuffer_consume(&session->internals.
record_buffer, bufel,
data_size);
ret =
merge_handshake_packet(session, &tmp);
if (ret < 0)
return gnutls_assert_val(ret);
}
while (_mbuffer_get_udata_size(bufel) > 0);
prev = bufel;
bufel =
_mbuffer_dequeue(&session->internals.
record_buffer, bufel);
_mbuffer_xfree(&prev);
continue;
next:
bufel = _mbuffer_head_get_next(bufel, NULL);
}
while (bufel != NULL);
/* sort in descending order */
if (session->internals.handshake_recv_buffer_size > 1)
qsort(recv_buf,
session->internals.
handshake_recv_buffer_size,
sizeof(recv_buf[0]), handshake_compare);
while (session->internals.handshake_recv_buffer_size > 0 &&
recv_buf[LAST_ELEMENT].sequence <
session->internals.dtls.hsk_read_seq) {
_gnutls_audit_log(session,
"Discarded replayed handshake packet with sequence %d\n",
recv_buf[LAST_ELEMENT].sequence);
_gnutls_handshake_buffer_clear(&recv_buf
[LAST_ELEMENT]);
session->internals.handshake_recv_buffer_size--;
}
return 0;
}
}
/* This function fragments and transmits a previously buffered
* outgoing message. It accepts mtu_data which is a buffer to
* be reused (should be set to NULL initially).
*/
static inline int
transmit_message (gnutls_session_t session,
mbuffer_st *bufel, uint8_t **buf)
{
uint8_t *data, *mtu_data;
int ret = 0;
unsigned int offset, frag_len, data_size;
const unsigned int mtu = gnutls_dtls_get_data_mtu(session) - DTLS_HANDSHAKE_HEADER_SIZE;
if (bufel->type == GNUTLS_CHANGE_CIPHER_SPEC)
{
_gnutls_dtls_log ("DTLS[%p]: Sending Packet[%u] fragment %s(%d)\n",
session, bufel->handshake_sequence,
_gnutls_handshake2str (bufel->htype),
bufel->htype);
return _gnutls_send_int (session, bufel->type, -1,
bufel->epoch,
_mbuffer_get_uhead_ptr(bufel),
_mbuffer_get_uhead_size(bufel), 0);
}
if (*buf == NULL) *buf = gnutls_malloc(mtu + DTLS_HANDSHAKE_HEADER_SIZE);
if (*buf == NULL)
return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
mtu_data = *buf;
data = _mbuffer_get_udata_ptr( bufel);
data_size = _mbuffer_get_udata_size(bufel);
/* Write fixed headers
*/
/* Handshake type */
mtu_data[0] = (uint8_t) bufel->htype;
/* Total length */
_gnutls_write_uint24 (data_size, &mtu_data[1]);
/* Handshake sequence */
_gnutls_write_uint16 (bufel->handshake_sequence, &mtu_data[4]);
/* Chop up and send handshake message into mtu-size pieces. */
for (offset=0; offset <= data_size; offset += mtu)
{
/* Calculate fragment length */
if(offset + mtu > data_size)
frag_len = data_size - offset;
else
frag_len = mtu;
/* Fragment offset */
_gnutls_write_uint24 (offset, &mtu_data[6]);
/* Fragment length */
_gnutls_write_uint24 (frag_len, &mtu_data[9]);
memcpy (&mtu_data[DTLS_HANDSHAKE_HEADER_SIZE], data+offset, frag_len);
_gnutls_dtls_log ("DTLS[%p]: Sending Packet[%u] fragment %s(%d) with "
"length: %u, offset: %u, fragment length: %u\n",
session, bufel->handshake_sequence,
_gnutls_handshake2str (bufel->htype),
bufel->htype, data_size, offset, frag_len);
ret = _gnutls_send_int (session, bufel->type, bufel->htype,
bufel->epoch, mtu_data, DTLS_HANDSHAKE_HEADER_SIZE + frag_len, 0);
if (ret < 0)
{
gnutls_assert();
break;
}
}
return ret;
}
static int
parse_handshake_header(gnutls_session_t session, mbuffer_st * bufel,
handshake_buffer_st * hsk)
{
uint8_t *dataptr = NULL; /* for realloc */
size_t handshake_header_size =
HANDSHAKE_HEADER_SIZE(session), data_size;
/* Note: SSL2_HEADERS == 1 */
if (_mbuffer_get_udata_size(bufel) < handshake_header_size)
return
gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
dataptr = _mbuffer_get_udata_ptr(bufel);
/* if reading a client hello of SSLv2 */
#ifdef ENABLE_SSL2
if (unlikely
(!IS_DTLS(session)
&& bufel->htype == GNUTLS_HANDSHAKE_CLIENT_HELLO_V2)) {
handshake_header_size = SSL2_HEADERS; /* we've already read one byte */
hsk->length = _mbuffer_get_udata_size(bufel) - handshake_header_size; /* we've read the first byte */
if (dataptr[0] != GNUTLS_HANDSHAKE_CLIENT_HELLO)
return
gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET);
hsk->htype = GNUTLS_HANDSHAKE_CLIENT_HELLO_V2;
hsk->sequence = 0;
hsk->start_offset = 0;
hsk->end_offset = hsk->length;
} else
#endif
{ /* TLS or DTLS handshake headers */
hsk->htype = dataptr[0];
/* we do not use DECR_LEN because we know
* that the packet has enough data.
*/
hsk->length = _gnutls_read_uint24(&dataptr[1]);
handshake_header_size = HANDSHAKE_HEADER_SIZE(session);
if (IS_DTLS(session)) {
hsk->sequence = _gnutls_read_uint16(&dataptr[4]);
hsk->start_offset =
_gnutls_read_uint24(&dataptr[6]);
hsk->end_offset =
hsk->start_offset +
_gnutls_read_uint24(&dataptr[9]);
} else {
hsk->sequence = 0;
hsk->start_offset = 0;
hsk->end_offset =
MIN((_mbuffer_get_udata_size(bufel) -
handshake_header_size), hsk->length);
}
}
data_size = _mbuffer_get_udata_size(bufel) - handshake_header_size;
/* make the length offset */
if (hsk->end_offset > 0)
hsk->end_offset--;
_gnutls_handshake_log
("HSK[%p]: %s (%u) was received. Length %d[%d], frag offset %d, frag length: %d, sequence: %d\n",
session, _gnutls_handshake2str(hsk->htype),
(unsigned) hsk->htype, (int) hsk->length, (int) data_size,
hsk->start_offset, hsk->end_offset - hsk->start_offset + 1,
(int) hsk->sequence);
hsk->header_size = handshake_header_size;
memcpy(hsk->header, _mbuffer_get_udata_ptr(bufel),
handshake_header_size);
if (hsk->length > 0 &&
(hsk->end_offset - hsk->start_offset >= data_size))
return
gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
if (hsk->length > 0 && (hsk->start_offset >= hsk->end_offset ||
hsk->end_offset - hsk->start_offset >=
data_size
|| hsk->end_offset >= hsk->length))
return
gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
else if (hsk->length == 0 && hsk->end_offset != 0
&& hsk->start_offset != 0)
return
gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
return handshake_header_size;
}
/* 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
* @target_length: @data_size + 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 target_length, 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;
record_state_st *record_state;
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;
}
if (data_size > MAX_USER_SEND_SIZE(session))
{
if (IS_DTLS(session))
return gnutls_assert_val(GNUTLS_E_LARGE_PACKET);
send_data_size = MAX_USER_SEND_SIZE(session);
}
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 && target_length == 0)))
return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
/* now proceed to packet encryption
*/
cipher_size = MAX_RECORD_SEND_SIZE(session);
bufel = _mbuffer_alloc (0, cipher_size+CIPHER_SLACK_SIZE);
if (bufel == NULL)
return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
headers = _mbuffer_get_uhead_ptr(bufel);
headers[0] = type;
/* Use the default record version, if it is
* set. */
copy_record_version (session, htype, &headers[1]);
header_size = RECORD_HEADER_SIZE(session);
/* Adjust header length and add sequence for DTLS */
if (IS_DTLS(session))
memcpy(&headers[3], &record_state->sequence_number.i, 8);
_gnutls_record_log
("REC[%p]: Preparing Packet %s(%d) with length: %d and target length: %d\n", session,
_gnutls_packet2str (type), type, (int) data_size, (int) target_length);
_mbuffer_set_udata_size(bufel, cipher_size);
_mbuffer_set_uhead_size(bufel, header_size);
ret =
_gnutls_encrypt (session,
data, send_data_size, target_length,
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[%d] %s(%d) in epoch %d and length: %d\n",
session,
(unsigned int)
_gnutls_uint64touint32
(&record_state->sequence_number),
_gnutls_packet2str (type), type,
(int) record_params->epoch,
(int) cipher_size);
return retval;
}
/* @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 *packet_sequence;
gnutls_datum_t ciphertext;
mbuffer_st* bufel = NULL, *decrypted = NULL;
gnutls_datum_t t;
int ret;
unsigned int empty_fragments = 0;
record_parameters_st *record_params;
record_state_st *record_state;
struct tls_record_st record;
begin:
if (empty_fragments > session->internals.priorities.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, type, htype, &record, &ms);
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, &ms);
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 (&session->internals.record_recv_buffer);
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);
/* We allocate the maximum possible to allow few compressed bytes to expand to a
* full record.
*/
decrypted = _mbuffer_alloc(record.length, record.length);
if (decrypted == NULL)
return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
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 (ret < 0)
{
gnutls_assert();
_gnutls_audit_log(session, "Discarded message[%u] due to invalid decryption\n",
(unsigned int)_gnutls_uint64touint32 (packet_sequence));
goto sanity_check_error;
}
/* check for duplicates. We check after the message
* is processed and authenticated to avoid someone
* messing with our windows.
*/
if (IS_DTLS(session) && session->internals.no_replay_protection == 0)
{
ret = _dtls_record_check(record_params, packet_sequence);
if (ret < 0)
{
_gnutls_audit_log(session, "Discarded duplicate message[%u.%u]: %s\n",
(unsigned int)record.sequence.i[0]*256 +(unsigned int)record.sequence.i[1],
(unsigned int) _gnutls_uint64touint32 (packet_sequence), _gnutls_packet2str (record.type));
goto sanity_check_error;
}
_gnutls_record_log
("REC[%p]: Decrypted Packet[%u.%u] %s(%d) with length: %d\n", session,
(unsigned int)record.sequence.i[0]*256 +(unsigned int)record.sequence.i[1],
(unsigned int) _gnutls_uint64touint32 (packet_sequence),
_gnutls_packet2str (record.type), record.type, (int)_mbuffer_get_udata_size(decrypted));
}
else
{
_gnutls_record_log
("REC[%p]: Decrypted Packet[%u] %s(%d) with length: %d\n", session,
(unsigned int) _gnutls_uint64touint32 (packet_sequence),
_gnutls_packet2str (record.type), record.type, (int)_mbuffer_get_udata_size(decrypted));
}
/* increase sequence number
*/
if (!IS_DTLS(session) && 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)
{
_mbuffer_xfree(&decrypted);
empty_fragments++;
goto begin;
}
if (record.v2)
decrypted->htype = GNUTLS_HANDSHAKE_CLIENT_HELLO_V2;
else
{
uint8_t * p = _mbuffer_get_udata_ptr(decrypted);
decrypted->htype = p[0];
}
ret =
record_add_to_buffers (session, &record, type, htype,
packet_sequence, decrypted);
/* bufel 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))
{
goto discard;
}
session_invalidate (session);
session_unresumable (session);
if (ret == 0)
return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
else
return ret;
}
/*
* Processes a heartbeat message.
*/
int _gnutls_heartbeat_handle(gnutls_session_t session, mbuffer_st * bufel)
{
int ret;
unsigned type;
unsigned pos;
uint8_t *msg = _mbuffer_get_udata_ptr(bufel);
size_t hb_len, len = _mbuffer_get_udata_size(bufel);
if (gnutls_heartbeat_allowed
(session, GNUTLS_HB_PEER_ALLOWED_TO_SEND) == 0)
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET);
if (len < 4)
return
gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
pos = 0;
type = msg[pos++];
hb_len = _gnutls_read_uint16(&msg[pos]);
if (hb_len > len - 3)
return
gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
pos += 2;
switch (type) {
case HEARTBEAT_REQUEST:
_gnutls_buffer_reset(&session->internals.hb_remote_data);
ret =
_gnutls_buffer_resize(&session->internals.
hb_remote_data, hb_len);
if (ret < 0)
return gnutls_assert_val(ret);
if (hb_len > 0)
memcpy(session->internals.hb_remote_data.data,
&msg[pos], hb_len);
session->internals.hb_remote_data.length = hb_len;
return gnutls_assert_val(GNUTLS_E_HEARTBEAT_PING_RECEIVED);
case HEARTBEAT_RESPONSE:
if (hb_len != session->internals.hb_local_data.length)
return
gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET);
if (hb_len > 0 &&
memcmp(&msg[pos],
session->internals.hb_local_data.data,
hb_len) != 0) {
if (IS_DTLS(session))
return gnutls_assert_val(GNUTLS_E_AGAIN); /* ignore it */
else
return
gnutls_assert_val
(GNUTLS_E_UNEXPECTED_PACKET);
}
_gnutls_buffer_reset(&session->internals.hb_local_data);
return gnutls_assert_val(GNUTLS_E_HEARTBEAT_PONG_RECEIVED);
default:
_gnutls_record_log
("REC[%p]: HB: received unknown type %u\n", session,
type);
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET);
}
}
/* This is a receive function for the gnutls handshake
* protocol. Makes sure that we have received all data.
*/
static int
parse_record_buffered_msgs (gnutls_session_t session,
gnutls_handshake_description_t htype,
handshake_buffer_st * hsk)
{
gnutls_datum_t msg;
mbuffer_st* bufel = NULL, *prev = NULL;
int ret;
size_t data_size;
handshake_buffer_st* recv_buf = session->internals.handshake_recv_buffer;
bufel = _mbuffer_head_get_first(&session->internals.record_buffer, &msg);
if (bufel == NULL)
return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;
if (!IS_DTLS(session))
{
ssize_t remain, append, header_size;
do
{
if (bufel->type != GNUTLS_HANDSHAKE)
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET);
/* if we have a half received message the complete it.
*/
remain = recv_buf[0].length -
recv_buf[0].data.length;
/* this is the rest of a previous message */
if (session->internals.handshake_recv_buffer_size > 0 && recv_buf[0].length > 0 && remain > 0)
{
if (msg.size <= remain)
append = msg.size;
else
append = remain;
ret = _gnutls_buffer_append_data(&recv_buf[0].data, msg.data, append);
if (ret < 0)
return gnutls_assert_val(ret);
_mbuffer_head_remove_bytes(&session->internals.record_buffer, append);
}
else /* received new message */
{
ret = parse_handshake_header(session, bufel, htype, &recv_buf[0]);
if (ret < 0)
return gnutls_assert_val(ret);
header_size = ret;
session->internals.handshake_recv_buffer_size = 1;
_mbuffer_set_uhead_size(bufel, header_size);
data_size = MIN(recv_buf[0].length, _mbuffer_get_udata_size(bufel));
ret = _gnutls_buffer_append_data(&recv_buf[0].data, _mbuffer_get_udata_ptr(bufel), data_size);
if (ret < 0)
return gnutls_assert_val(ret);
_mbuffer_set_uhead_size(bufel, 0);
_mbuffer_head_remove_bytes(&session->internals.record_buffer, data_size+header_size);
if (cmp_hsk_types(htype, recv_buf[0].htype) == 0)
{ /* an unexpected packet */
hsk->htype = recv_buf[0].htype;
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_HANDSHAKE_PACKET);
}
}
/* if packet is complete then return it
*/
if (recv_buf[0].length ==
recv_buf[0].data.length)
{
return get_last_packet(session, htype, hsk);
}
bufel = _mbuffer_head_get_first(&session->internals.record_buffer, &msg);
}
while(bufel != NULL);
/* if we are here it means that the received packets were not
* enough to complete the handshake packet.
*/
return gnutls_assert_val(GNUTLS_E_AGAIN);
}
else /* DTLS */
{
handshake_buffer_st tmp;
do
{
/* we now
* 0. parse headers
* 1. insert to handshake_recv_buffer
* 2. sort handshake_recv_buffer on sequence numbers
* 3. return first packet if completed or GNUTLS_E_AGAIN.
*/
do
{
if (bufel->type != GNUTLS_HANDSHAKE)
{
gnutls_assert();
goto next; /* ignore packet */
}
_gnutls_handshake_buffer_init(&tmp);
ret = parse_handshake_header(session, bufel, htype, &tmp);
if (ret < 0)
{
gnutls_assert();
_gnutls_audit_log("Invalid handshake packet headers. Discarding.\n");
break;
}
_mbuffer_consume(&session->internals.record_buffer, bufel, ret);
data_size = MIN(tmp.length, tmp.end_offset-tmp.start_offset+1);
ret = _gnutls_buffer_append_data(&tmp.data, _mbuffer_get_udata_ptr(bufel), data_size);
if (ret < 0)
return gnutls_assert_val(ret);
_mbuffer_consume(&session->internals.record_buffer, bufel, data_size);
ret = merge_handshake_packet(session, &tmp);
if (ret < 0)
return gnutls_assert_val(ret);
}
while(_mbuffer_get_udata_size(bufel) > 0);
prev = bufel;
bufel = _mbuffer_dequeue(&session->internals.record_buffer, bufel);
_mbuffer_xfree(&prev);
continue;
next:
bufel = _mbuffer_head_get_next(bufel, NULL);
}
while(bufel != NULL);
/* sort in descending order */
if (session->internals.handshake_recv_buffer_size > 1)
qsort(recv_buf, session->internals.handshake_recv_buffer_size,
sizeof(recv_buf[0]), handshake_compare);
while(session->internals.handshake_recv_buffer_size > 0 &&
recv_buf[LAST_ELEMENT].sequence < session->internals.dtls.hsk_read_seq)
{
_gnutls_audit_log("Discarded replayed handshake packet with sequence %d\n", recv_buf[LAST_ELEMENT].sequence);
_gnutls_handshake_buffer_clear(&recv_buf[LAST_ELEMENT]);
session->internals.handshake_recv_buffer_size--;
}
return get_last_packet(session, htype, hsk);
}
}
/* returns ciphertext which contains the headers too. This also
* calculates the size in the header field.
*
*/
int
_gnutls_encrypt(gnutls_session_t session,
const uint8_t * data, size_t data_size,
size_t min_pad,
mbuffer_st * bufel,
content_type_t type, record_parameters_st * params)
{
gnutls_datum_t comp;
int free_comp = 0;
int ret;
if (data_size == 0 || is_write_comp_null(params) == 0) {
comp.data = (uint8_t *) data;
comp.size = data_size;
} else {
/* Here comp is allocated and must be
* freed.
*/
free_comp = 1;
comp.size = _mbuffer_get_udata_size(bufel);
comp.data = gnutls_malloc(comp.size);
if (comp.data == NULL)
return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
ret =
_gnutls_compress(¶ms->write.compression_state,
data, data_size, comp.data, comp.size,
session->internals.priorities.
stateless_compression);
if (ret < 0) {
gnutls_free(comp.data);
return gnutls_assert_val(ret);
}
comp.size = ret;
}
ret =
compressed_to_ciphertext(session,
_mbuffer_get_udata_ptr(bufel),
_mbuffer_get_udata_size
(bufel), &comp, min_pad, type,
params);
if (free_comp)
gnutls_free(comp.data);
if (ret < 0)
return gnutls_assert_val(ret);
if (IS_DTLS(session))
_gnutls_write_uint16(ret,
((uint8_t *)
_mbuffer_get_uhead_ptr(bufel)) + 11);
else
_gnutls_write_uint16(ret,
((uint8_t *)
_mbuffer_get_uhead_ptr(bufel)) + 3);
_mbuffer_set_udata_size(bufel, ret);
_mbuffer_set_uhead_size(bufel, 0);
return _mbuffer_get_udata_size(bufel);
}
