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/*
* Copyright (C) 2001, 2004, 2005 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
*
*/
/* This file contains the code for the Max Record Size TLS extension.
*/
#include "gnutls_int.h"
#include "gnutls_errors.h"
#include "gnutls_num.h"
#include <ext_max_record.h>
/*
* In case of a server: if a MAX_RECORD_SIZE extension type is received then it stores
* into the session the new value. The server may use MHD_gnutls_get_max_record_size(),
* in order to access it.
*
* In case of a client: If a different max record size (than the default) has
* been specified then it sends the extension.
*
*/
int
MHD_gtls_max_record_recv_params (MHD_gtls_session_t session,
const opaque * data, size_t _data_size)
{
ssize_t new_size;
ssize_t data_size = _data_size;
if (session->security_parameters.entity == GNUTLS_SERVER)
{
if (data_size > 0)
{
DECR_LEN (data_size, 1);
new_size = MHD_gtls_mre_num2record (data[0]);
if (new_size < 0)
{
MHD_gnutls_assert ();
return new_size;
}
session->security_parameters.max_record_send_size = new_size;
session->security_parameters.max_record_recv_size = new_size;
}
}
else
{ /* CLIENT SIDE - we must check if the sent record size is the right one
*/
if (data_size > 0)
{
if (data_size != 1)
{
MHD_gnutls_assert ();
return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
}
new_size = MHD_gtls_mre_num2record (data[0]);
if (new_size < 0
|| new_size != session->internals.proposed_record_size)
{
MHD_gnutls_assert ();
return GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER;
}
else
{
session->security_parameters.max_record_recv_size =
session->internals.proposed_record_size;
}
}
}
return 0;
}
/* returns data_size or a negative number on failure
*/
int
MHD_gtls_max_record_send_params (MHD_gtls_session_t session, opaque * data,
size_t data_size)
{
uint16_t len;
/* this function sends the client extension data (dnsname) */
#if MHD_DEBUG_TLS
if (session->security_parameters.entity == GNUTLS_CLIENT)
{
if (session->internals.proposed_record_size != DEFAULT_MAX_RECORD_SIZE)
{
len = 1;
if (data_size < len)
{
MHD_gnutls_assert ();
return GNUTLS_E_SHORT_MEMORY_BUFFER;
}
data[0] =
(uint8_t) MHD_gtls_mre_record2num (session->internals.
proposed_record_size);
return len;
}
}
else
#endif
{ /* server side */
if (session->security_parameters.max_record_recv_size !=
DEFAULT_MAX_RECORD_SIZE)
{
len = 1;
if (data_size < len)
{
MHD_gnutls_assert ();
return GNUTLS_E_SHORT_MEMORY_BUFFER;
}
data[0] =
(uint8_t)
MHD_gtls_mre_record2num
(session->security_parameters.max_record_recv_size);
return len;
}
}
return 0;
}
/* Maps numbers to record sizes according to the
* extensions draft.
*/
int
MHD_gtls_mre_num2record (int num)
{
switch (num)
{
case 1:
return 512;
case 2:
return 1024;
case 3:
return 2048;
case 4:
return 4096;
default:
return GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER;
}
}
/* Maps record size to numbers according to the
* extensions draft.
*/
int
MHD_gtls_mre_record2num (uint16_t record_size)
{
switch (record_size)
{
case 512:
return 1;
case 1024:
return 2;
case 2048:
return 3;
case 4096:
return 4;
default:
return GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER;
}
}
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