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|
/*
* Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation
*
* Author: Nikos Mavrogiannopoulos
*
* This file is part of GNUTLS.
*
* The GNUTLS library 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA
*
*/
/* Functions that are record layer specific, are included in this file.
*/
#include "gnutls_int.h"
#include "gnutls_errors.h"
#include "debug.h"
#include "gnutls_compress.h"
#include "gnutls_cipher.h"
#include "gnutls_buffers.h"
#include "gnutls_handshake.h"
#include "gnutls_hash_int.h"
#include "gnutls_cipher_int.h"
#include "gnutls_algorithms.h"
#include "gnutls_auth_int.h"
#include "gnutls_num.h"
#include "gnutls_record.h"
#include "gnutls_datum.h"
#include "ext_max_record.h"
#include <gnutls_state.h>
#include <gnutls_dh.h>
/**
* MHD__gnutls_protocol_get_version - Returns the version of the currently used protocol
* @session: is a #MHD_gtls_session_t structure.
*
* Returns: the version of the currently used protocol.
**/
enum MHD_GNUTLS_Protocol
MHD__gnutls_protocol_get_version (MHD_gtls_session_t session)
{
return session->security_parameters.version;
}
void
MHD_gtls_set_current_version (MHD_gtls_session_t session,
enum MHD_GNUTLS_Protocol version)
{
session->security_parameters.version = version;
}
/**
* MHD__gnutls_transport_set_lowat - Used to set the lowat value in order for select to check for pending data.
* @session: is a #MHD_gtls_session_t structure.
* @num: is the low water value.
*
* Used to set the lowat value in order for select to check if there
* are pending data to socket buffer. Used only if you have changed
* the default low water value (default is 1). Normally you will not
* need that function. This function is only useful if using
* berkeley style sockets. Otherwise it must be called and set lowat
* to zero.
**/
void
MHD__gnutls_transport_set_lowat (MHD_gtls_session_t session, int num)
{
session->internals.lowat = num;
}
/**
* MHD__gnutls_transport_set_ptr - Used to set first argument of the transport functions
* @session: is a #MHD_gtls_session_t structure.
* @ptr: is the value.
*
* Used to set the first argument of the transport function (like
* PUSH and PULL). In berkeley style sockets this function will set
* the connection handle.
**/
void
MHD__gnutls_transport_set_ptr (MHD_gtls_session_t session,
MHD_gnutls_transport_ptr_t ptr)
{
session->internals.transport_recv_ptr = ptr;
session->internals.transport_send_ptr = ptr;
}
/**
* MHD__gnutls_bye - This function terminates the current TLS/SSL connection.
* @session: is a #MHD_gtls_session_t structure.
* @how: is an integer
*
* Terminates the current TLS/SSL connection. The connection should
* have been initiated using MHD__gnutls_handshake(). @how should be one
* of %GNUTLS_SHUT_RDWR, %GNUTLS_SHUT_WR.
*
* In case of %GNUTLS_SHUT_RDWR then the TLS connection gets
* terminated and further receives and sends will be disallowed. If
* the return value is zero you may continue using the connection.
* %GNUTLS_SHUT_RDWR actually sends an alert containing a close
* request and waits for the peer to reply with the same message.
*
* In case of %GNUTLS_SHUT_WR then the TLS connection 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, thus causing a
* transmission error to the peer. This error cannot be
* distinguished from a malicious party prematurely terminating the
* session, thus this behavior is not recommended.
*
* This function may also return %GNUTLS_E_AGAIN or
* %GNUTLS_E_INTERRUPTED; cf. MHD__gnutls_record_get_direction().
*
* Returns: %GNUTLS_E_SUCCESS on success, or an error code, see
* function documentation for entire semantics.
**/
int
MHD__gnutls_bye (MHD_gtls_session_t session, MHD_gnutls_close_request_t how)
{
int ret = 0;
switch (STATE)
{
case STATE0:
case STATE60:
ret = MHD_gtls_io_write_flush (session);
STATE = STATE60;
if (ret < 0)
{
MHD_gnutls_assert ();
return ret;
}
case STATE61:
ret =
MHD__gnutls_alert_send (session, GNUTLS_AL_WARNING,
GNUTLS_A_CLOSE_NOTIFY);
STATE = STATE61;
if (ret < 0)
{
MHD_gnutls_assert ();
return ret;
}
case STATE62:
STATE = STATE62;
if (how == GNUTLS_SHUT_RDWR)
{
do
{
MHD_gtls_io_clear_peeked_data (session);
ret = MHD_gtls_recv_int (session, GNUTLS_ALERT, -1, NULL, 0);
}
while (ret == GNUTLS_E_GOT_APPLICATION_DATA);
if (ret >= 0)
session->internals.may_not_read = 1;
if (ret < 0)
{
MHD_gnutls_assert ();
return ret;
}
}
STATE = STATE62;
break;
default:
MHD_gnutls_assert ();
return GNUTLS_E_INTERNAL_ERROR;
}
STATE = STATE0;
session->internals.may_not_write = 1;
return 0;
}
inline static void
session_invalidate (MHD_gtls_session_t session)
{
session->internals.valid_connection = VALID_FALSE;
}
inline static void
session_unresumable (MHD_gtls_session_t session)
{
session->internals.resumable = RESUME_FALSE;
}
/* returns 0 if session is valid
*/
inline static int
session_is_valid (MHD_gtls_session_t session)
{
if (session->internals.valid_connection == VALID_FALSE)
return GNUTLS_E_INVALID_SESSION;
return 0;
}
/* Copies the record version into the headers. The
* version must have 2 bytes at least.
*/
inline static void
copy_record_version (MHD_gtls_session_t session,
MHD_gnutls_handshake_description_t htype,
opaque version[2])
{
enum MHD_GNUTLS_Protocol lver;
if (htype != GNUTLS_HANDSHAKE_CLIENT_HELLO
|| session->internals.default_record_version[0] == 0)
{
lver = MHD__gnutls_protocol_get_version (session);
version[0] = MHD_gtls_version_get_major (lver);
version[1] = MHD_gtls_version_get_minor (lver);
}
else
{
version[0] = session->internals.default_record_version[0];
version[1] = session->internals.default_record_version[1];
}
}
/* This function behaves exactly like write(). The only difference is
* that it accepts, the MHD_gtls_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.
*
* 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
MHD_gtls_send_int (MHD_gtls_session_t session,
content_type_t type,
MHD_gnutls_handshake_description_t htype,
const void *_data, size_t sizeofdata)
{
uint8_t *cipher;
int cipher_size;
int retval, ret;
int data2send_size;
uint8_t headers[5];
const uint8_t *data = _data;
/* 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.length == 0 && (sizeofdata == 0
&& _data == NULL))
{
MHD_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)
{
MHD_gnutls_assert ();
return GNUTLS_E_INVALID_SESSION;
}
headers[0] = type;
/* Use the default record version, if it is
* set.
*/
copy_record_version (session, htype, &headers[1]);
MHD__gnutls_record_log
("REC[%x]: Sending Packet[%d] %s(%d) with length: %d\n", session,
(int) MHD_gtls_uint64touint32 (&session->
connection_state.write_sequence_number),
MHD__gnutls_packet2str (type), type, sizeofdata);
if (sizeofdata > MAX_RECORD_SEND_SIZE)
data2send_size = MAX_RECORD_SEND_SIZE;
else
data2send_size = sizeofdata;
/* Only encrypt if we don't have data to send
* from the previous run. - probably interrupted.
*/
if (session->internals.record_send_buffer.length > 0)
{
ret = MHD_gtls_io_write_flush (session);
if (ret > 0)
cipher_size = ret;
else
cipher_size = 0;
cipher = NULL;
retval = session->internals.record_send_buffer_user_size;
}
else
{
/* now proceed to packet encryption
*/
cipher_size = data2send_size + MAX_RECORD_OVERHEAD;
cipher = MHD_gnutls_malloc (cipher_size);
if (cipher == NULL)
{
MHD_gnutls_assert ();
return GNUTLS_E_MEMORY_ERROR;
}
cipher_size =
MHD_gtls_encrypt (session, headers, RECORD_HEADER_SIZE, data,
data2send_size, cipher, cipher_size, type,
(session->internals.priorities.no_padding ==
0) ? 1 : 0);
if (cipher_size <= 0)
{
MHD_gnutls_assert ();
if (cipher_size == 0)
cipher_size = GNUTLS_E_ENCRYPTION_FAILED;
MHD_gnutls_free (cipher);
return cipher_size; /* error */
}
retval = data2send_size;
session->internals.record_send_buffer_user_size = data2send_size;
/* increase sequence number
*/
if (MHD_gtls_uint64pp
(&session->connection_state.write_sequence_number) != 0)
{
session_invalidate (session);
MHD_gnutls_assert ();
MHD_gnutls_free (cipher);
return GNUTLS_E_RECORD_LIMIT_REACHED;
}
ret = MHD_gtls_io_write_buffered (session, cipher, cipher_size);
MHD_gnutls_free (cipher);
}
if (ret != cipher_size)
{
if (ret < 0 && MHD_gtls_error_is_fatal (ret) == 0)
{
/* If we have sent any data then just return
* the error value. Do not invalidate the session.
*/
MHD_gnutls_assert ();
return ret;
}
if (ret > 0)
{
MHD_gnutls_assert ();
ret = GNUTLS_E_INTERNAL_ERROR;
}
session_unresumable (session);
session->internals.may_not_write = 1;
MHD_gnutls_assert ();
return ret;
}
session->internals.record_send_buffer_user_size = 0;
MHD__gnutls_record_log ("REC[%x]: Sent Packet[%d] %s(%d) with length: %d\n",
session,
(int)
MHD_gtls_uint64touint32
(&session->connection_state.write_sequence_number),
MHD__gnutls_packet2str (type), type, cipher_size);
return retval;
}
/* This function is to be called if the handshake was successfully
* completed. This sends a Change Cipher Spec packet to the peer.
*/
ssize_t
MHD_gtls_send_change_cipher_spec (MHD_gtls_session_t session, int again)
{
static const opaque data[1] = {
GNUTLS_TYPE_CHANGE_CIPHER_SPEC
};
MHD__gnutls_handshake_log ("REC[%x]: Sent ChangeCipherSpec\n", session);
if (again == 0)
return MHD_gtls_send_int (session, GNUTLS_CHANGE_CIPHER_SPEC, -1, data,
1);
else
{
return MHD_gtls_io_write_flush (session);
}
}
inline static int
check_recv_type (content_type_t recv_type)
{
switch (recv_type)
{
case GNUTLS_CHANGE_CIPHER_SPEC:
case GNUTLS_ALERT:
case GNUTLS_HANDSHAKE:
case GNUTLS_APPLICATION_DATA:
case GNUTLS_INNER_APPLICATION:
return 0;
default:
MHD_gnutls_assert ();
return GNUTLS_A_UNEXPECTED_MESSAGE;
}
}
/* Checks if there are pending data in the record buffers. If there are
* then it copies the data.
*/
static int
check_buffers (MHD_gtls_session_t session,
content_type_t type, opaque * data, int sizeofdata)
{
if ((type == GNUTLS_APPLICATION_DATA || type == GNUTLS_HANDSHAKE || type
== GNUTLS_INNER_APPLICATION)
&& MHD_gnutls_record_buffer_get_size (type, session) > 0)
{
int ret, ret2;
ret = MHD_gtls_record_buffer_get (type, session, data, sizeofdata);
if (ret < 0)
{
MHD_gnutls_assert ();
return ret;
}
/* if the buffer just got empty */
if (MHD_gnutls_record_buffer_get_size (type, session) == 0)
{
if ((ret2 = MHD_gtls_io_clear_peeked_data (session)) < 0)
{
MHD_gnutls_assert ();
return ret2;
}
}
return ret;
}
return 0;
}
/* Checks the record headers and returns the length, version and
* content type.
*/
static int
record_check_headers (MHD_gtls_session_t session,
uint8_t headers[RECORD_HEADER_SIZE],
content_type_t type,
MHD_gnutls_handshake_description_t htype,
/*output */ content_type_t * recv_type,
opaque version[2],
uint16_t * length, uint16_t * header_size)
{
/* Read the first two bytes to determine if this is a
* version 2 message
*/
if (htype == GNUTLS_HANDSHAKE_CLIENT_HELLO && type == GNUTLS_HANDSHAKE
&& headers[0] > 127)
{
/* if msb set and expecting handshake message
* it should be SSL 2 hello
*/
version[0] = 3; /* assume SSL 3.0 */
version[1] = 0;
*length = (((headers[0] & 0x7f) << 8)) | headers[1];
/* SSL 2.0 headers */
*header_size = 2;
*recv_type = GNUTLS_HANDSHAKE; /* we accept only v2 client hello
*/
/* in order to assist the handshake protocol.
* V2 compatibility is a mess.
*/
session->internals.v2_hello = *length;
MHD__gnutls_record_log ("REC[%x]: V2 packet received. Length: %d\n",
session, *length);
}
else
{
/* version 3.x */
*recv_type = headers[0];
version[0] = headers[1];
version[1] = headers[2];
/* No DECR_LEN, since headers has enough size.
*/
*length = MHD_gtls_read_uint16 (&headers[3]);
}
return 0;
}
/* Here we check if the advertized version is the one we
* negotiated in the handshake.
*/
inline static int
record_check_version (MHD_gtls_session_t session,
MHD_gnutls_handshake_description_t htype,
opaque version[2])
{
if (htype == GNUTLS_HANDSHAKE_CLIENT_HELLO)
{
/* Reject hello packets with major version higher than 3.
*/
if (version[0] > 3)
{
MHD_gnutls_assert ();
MHD__gnutls_record_log
("REC[%x]: INVALID VERSION PACKET: (%d) %d.%d\n", session,
htype, version[0], version[1]);
return GNUTLS_E_UNSUPPORTED_VERSION_PACKET;
}
}
else if (htype != GNUTLS_HANDSHAKE_SERVER_HELLO
&& MHD__gnutls_protocol_get_version (session)
!= MHD_gtls_version_get (version[0], version[1]))
{
/* 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.
*/
MHD_gnutls_assert ();
MHD__gnutls_record_log ("REC[%x]: INVALID VERSION PACKET: (%d) %d.%d\n",
session, htype, version[0], version[1]);
return GNUTLS_E_UNSUPPORTED_VERSION_PACKET;
}
return 0;
}
/* This function will check if the received record type is
* the one we actually expect.
*/
static int
record_check_type (MHD_gtls_session_t session,
content_type_t recv_type,
content_type_t type,
MHD_gnutls_handshake_description_t htype,
opaque * data, int data_size)
{
int ret;
if ((recv_type == type) && (type == GNUTLS_APPLICATION_DATA || type
== GNUTLS_HANDSHAKE
|| type == GNUTLS_INNER_APPLICATION))
{
MHD_gnutls_record_buffer_put (type, session, (void *) data, data_size);
}
else
{
switch (recv_type)
{
case GNUTLS_ALERT:
MHD__gnutls_record_log
("REC[%x]: Alert[%d|%d] - %s - was received\n", session,
data[0], data[1], MHD__gnutls_alert_get_name ((int) data[1]));
session->internals.last_alert = data[1];
session->internals.last_alert_level = data[0];
/* if close notify is received and
* the alert is not fatal
*/
if (data[1] == GNUTLS_A_CLOSE_NOTIFY && data[0] != GNUTLS_AL_FATAL)
{
/* If we have been expecting for an alert do
*/
session->internals.read_eof = 1;
return GNUTLS_E_INT_RET_0; /* EOF */
}
else
{
/* if the alert is FATAL or WARNING
* return the apropriate message
*/
MHD_gnutls_assert ();
ret = GNUTLS_E_WARNING_ALERT_RECEIVED;
if (data[0] == GNUTLS_AL_FATAL)
{
session_unresumable (session);
session_invalidate (session);
ret = GNUTLS_E_FATAL_ALERT_RECEIVED;
}
return ret;
}
break;
case GNUTLS_CHANGE_CIPHER_SPEC:
/* this packet is now handled in the recv_int()
* function
*/
MHD_gnutls_assert ();
return GNUTLS_E_UNEXPECTED_PACKET;
case GNUTLS_APPLICATION_DATA:
/* even if data is unexpected put it into the buffer */
if ((ret =
MHD_gnutls_record_buffer_put (recv_type, session,
(void *) data, data_size)) < 0)
{
MHD_gnutls_assert ();
return ret;
}
/* 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_CLIENT_HELLO
&& type == GNUTLS_HANDSHAKE))
return GNUTLS_E_GOT_APPLICATION_DATA;
else
{
MHD_gnutls_assert ();
return GNUTLS_E_UNEXPECTED_PACKET;
}
break;
case GNUTLS_HANDSHAKE:
/* 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)
{
MHD_gnutls_assert ();
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 */
return MHD_gtls_recv_hello_request (session, data, data_size);
break;
case GNUTLS_INNER_APPLICATION:
/* even if data is unexpected put it into the buffer */
if ((ret =
MHD_gnutls_record_buffer_put (recv_type, session,
(void *) data, data_size)) < 0)
{
MHD_gnutls_assert ();
return ret;
}
MHD_gnutls_assert ();
return GNUTLS_E_UNEXPECTED_PACKET;
break;
default:
MHD__gnutls_record_log
("REC[%x]: Received Unknown packet %d expecting %d\n",
session, recv_type, type);
MHD_gnutls_assert ();
return GNUTLS_E_INTERNAL_ERROR;
}
}
return 0;
}
/* This function will return the internal (per session) temporary
* recv buffer. If the buffer was not initialized before it will
* also initialize it.
*/
inline static int
get_temp_recv_buffer (MHD_gtls_session_t session, MHD_gnutls_datum_t * tmp)
{
size_t max_record_size;
if (MHD_gtls_compression_get (session) != MHD_GNUTLS_COMP_NULL)
max_record_size = MAX_RECORD_RECV_SIZE + EXTRA_COMP_SIZE;
else
max_record_size = MAX_RECORD_RECV_SIZE;
/* We allocate MAX_RECORD_RECV_SIZE length
* because we cannot predict the output data by the record
* packet length (due to compression).
*/
if (max_record_size > session->internals.recv_buffer.size
|| session->internals.recv_buffer.data == NULL)
{
/* Initialize the internal buffer.
*/
session->internals.recv_buffer.data
=
MHD_gnutls_realloc (session->internals.recv_buffer.data,
max_record_size);
if (session->internals.recv_buffer.data == NULL)
{
MHD_gnutls_assert ();
return GNUTLS_E_MEMORY_ERROR;
}
session->internals.recv_buffer.size = max_record_size;
}
tmp->data = session->internals.recv_buffer.data;
tmp->size = session->internals.recv_buffer.size;
return 0;
}
#define MAX_EMPTY_PACKETS_SEQUENCE 4
/* This function behaves exactly like read(). The only difference is
* that it accepts the MHD_gtls_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.
*
* The MHD_gnutls_handshake_description_t was introduced to support SSL V2.0 client hellos.
*/
ssize_t
MHD_gtls_recv_int (MHD_gtls_session_t session,
content_type_t type,
MHD_gnutls_handshake_description_t htype,
opaque * data, size_t sizeofdata)
{
MHD_gnutls_datum_t tmp;
int decrypted_length;
opaque version[2];
uint8_t *headers;
content_type_t recv_type;
uint16_t length;
uint8_t *ciphertext;
uint8_t *recv_data;
int ret, ret2;
uint16_t header_size;
int empty_packet = 0;
if (type != GNUTLS_ALERT && (sizeofdata == 0 || data == NULL))
{
return GNUTLS_E_INVALID_REQUEST;
}
begin:
if (empty_packet > MAX_EMPTY_PACKETS_SEQUENCE)
{
MHD_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)
{
MHD_gnutls_assert ();
return GNUTLS_E_INVALID_SESSION;
}
/* If we have enough data in the cache do not bother receiving
* a new packet. (in order to flush the cache)
*/
ret = check_buffers (session, type, data, sizeofdata);
if (ret != 0)
return ret;
/* default headers for TLS 1.0
*/
header_size = RECORD_HEADER_SIZE;
if ((ret = MHD_gtls_io_read_buffered (session, &headers, header_size, -1))
!= header_size)
{
if (ret < 0 && MHD_gtls_error_is_fatal (ret) == 0)
return ret;
session_invalidate (session);
if (type == GNUTLS_ALERT)
{
MHD_gnutls_assert ();
return 0; /* we were expecting close notify */
}
session_unresumable (session);
MHD_gnutls_assert ();
return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
}
if ((ret = record_check_headers (session, headers, type, htype, &recv_type,
version, &length, &header_size)) < 0)
{
MHD_gnutls_assert ();
return ret;
}
/* Here we check if the Type of the received packet is
* ok.
*/
if ((ret = check_recv_type (recv_type)) < 0)
{
MHD_gnutls_assert ();
return ret;
}
/* Here we check if the advertized version is the one we
* negotiated in the handshake.
*/
if ((ret = record_check_version (session, htype, version)) < 0)
{
MHD_gnutls_assert ();
session_invalidate (session);
return ret;
}
MHD__gnutls_record_log
("REC[%x]: Expected Packet[%d] %s(%d) with length: %d\n", session,
(int) MHD_gtls_uint64touint32 (&session->
connection_state.read_sequence_number),
MHD__gnutls_packet2str (type), type, sizeofdata);
MHD__gnutls_record_log
("REC[%x]: Received Packet[%d] %s(%d) with length: %d\n", session,
(int) MHD_gtls_uint64touint32 (&session->
connection_state.read_sequence_number),
MHD__gnutls_packet2str (recv_type), recv_type, length);
if (length > MAX_RECV_SIZE)
{
MHD__gnutls_record_log
("REC[%x]: FATAL ERROR: Received packet with length: %d\n",
session, length);
session_unresumable (session);
session_invalidate (session);
MHD_gnutls_assert ();
return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
}
/* check if we have that data into buffer.
*/
if ((ret = MHD_gtls_io_read_buffered (session, &recv_data,
header_size + length, recv_type))
!= header_size + length)
{
if (ret < 0 && MHD_gtls_error_is_fatal (ret) == 0)
return ret;
session_unresumable (session);
session_invalidate (session);
MHD_gnutls_assert ();
return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
}
/* ok now we are sure that we can read all the data - so
* move on !
*/
MHD_gtls_io_clear_read_buffer (session);
ciphertext = &recv_data[header_size];
ret = get_temp_recv_buffer (session, &tmp);
if (ret < 0)
{
MHD_gnutls_assert ();
return ret;
}
/* decrypt the data we got. */
ret = MHD_gtls_decrypt (session, ciphertext, length, tmp.data, tmp.size,
recv_type);
if (ret < 0)
{
session_unresumable (session);
session_invalidate (session);
MHD_gnutls_assert ();
return ret;
}
decrypted_length = ret;
/* Check if this is a CHANGE_CIPHER_SPEC
*/
if (type == GNUTLS_CHANGE_CIPHER_SPEC && recv_type
== GNUTLS_CHANGE_CIPHER_SPEC)
{
MHD__gnutls_record_log
("REC[%x]: ChangeCipherSpec Packet was received\n", session);
if ((size_t) ret != sizeofdata)
{ /* sizeofdata should be 1 */
MHD_gnutls_assert ();
return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
}
memcpy (data, tmp.data, sizeofdata);
return ret;
}
MHD__gnutls_record_log
("REC[%x]: Decrypted Packet[%d] %s(%d) with length: %d\n", session,
(int) MHD_gtls_uint64touint32 (&session->
connection_state.read_sequence_number),
MHD__gnutls_packet2str (recv_type), recv_type, decrypted_length);
/* increase sequence number
*/
if (MHD_gtls_uint64pp (&session->connection_state.read_sequence_number) !=
0)
{
session_invalidate (session);
MHD_gnutls_assert ();
return GNUTLS_E_RECORD_LIMIT_REACHED;
}
/* check type - this will also invalidate sessions if a fatal alert has been received */
ret = record_check_type (session, recv_type, type, htype, tmp.data,
decrypted_length);
if (ret < 0)
{
if (ret == GNUTLS_E_INT_RET_0)
return 0;
MHD_gnutls_assert ();
return ret;
}
/* Get Application data from buffer
*/
if ((recv_type == type) && (type == GNUTLS_APPLICATION_DATA || type
== GNUTLS_HANDSHAKE
|| type == GNUTLS_INNER_APPLICATION))
{
ret = MHD_gtls_record_buffer_get (type, session, data, sizeofdata);
if (ret < 0)
{
MHD_gnutls_assert ();
return ret;
}
/* if the buffer just got empty
*/
if (MHD_gnutls_record_buffer_get_size (type, session) == 0)
{
if ((ret2 = MHD_gtls_io_clear_peeked_data (session)) < 0)
{
MHD_gnutls_assert ();
return ret2;
}
}
}
else
{
MHD_gnutls_assert ();
return GNUTLS_E_UNEXPECTED_PACKET;
/* we didn't get what we wanted to
*/
}
/* (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 (ret == 0)
{
empty_packet++;
goto begin;
}
return ret;
}
/**
* MHD__gnutls_record_send - sends to the peer the specified data
* @session: is a #MHD_gtls_session_t structure.
* @data: contains the data to send
* @sizeofdata: is the length of the data
*
* This function has the similar semantics with send(). The only
* difference is that is 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 full information. You
* can replace the default push function by using
* MHD__gnutls_transport_set_ptr2() with a call to send() with a
* MSG_DONTWAIT flag if blocking is a problem.
*
* If the EINTR is returned by the internal push function (the
* default is send()} 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 same parameters; alternatively
* you could provide a %NULL pointer for data, and 0 for
* size. cf. MHD__gnutls_record_get_direction().
*
* Returns: the number of bytes sent, or a negative error code. The
* number of bytes sent might be less than @sizeofdata. The maximum
* number of bytes this function can send in a single call depends on
* the negotiated maximum record size.
**/
ssize_t
MHD__gnutls_record_send (MHD_gtls_session_t session,
const void *data, size_t sizeofdata)
{
return MHD_gtls_send_int (session, GNUTLS_APPLICATION_DATA, -1, data,
sizeofdata);
}
/**
* MHD__gnutls_record_recv - reads data from the TLS record protocol
* @session: is a #MHD_gtls_session_t structure.
* @data: the buffer that the data will be read into
* @sizeofdata: the number of requested bytes
*
* This function has the similar semantics with recv(). The only
* difference is that is accepts a GNUTLS session, and uses different
* error codes.
*
* In the special case that a server requests a renegotiation, the
* client may receive an error code of %GNUTLS_E_REHANDSHAKE. This
* message may be simply ignored, replied with an alert containing
* NO_RENEGOTIATION, or replied with a new handshake, depending on
* the client's will.
*
* If %EINTR is returned by the internal push 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
* MHD__gnutls_record_get_direction().
*
* A server may also receive %GNUTLS_E_REHANDSHAKE when a client has
* initiated a handshake. In that case the server can only initiate a
* handshake or terminate the connection.
*
* 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 @sizeofdata.
**/
ssize_t
MHD__gnutls_record_recv (MHD_gtls_session_t session, void *data,
size_t sizeofdata)
{
return MHD_gtls_recv_int (session, GNUTLS_APPLICATION_DATA, -1, data,
sizeofdata);
}
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