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/*
* Copyright (C) 2001, 2002, 2003, 2004, 2005, 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 relate to the TLS hello extension parsing.
* Hello extensions are packets appended in the TLS hello packet, and
* allow for extra functionality.
*/
#include "MHD_config.h"
#include "gnutls_int.h"
#include "gnutls_extensions.h"
#include "gnutls_errors.h"
#include "ext_max_record.h"
#include <ext_cert_type.h>
#include <ext_server_name.h>
#include <ext_oprfi.h>
#include <gnutls_num.h>
/* Key Exchange Section */
#define GNUTLS_EXTENSION_ENTRY(type, parse_type, ext_func_recv, ext_func_send) \
{ #type, type, parse_type, ext_func_recv, ext_func_send }
#define MAX_EXT_SIZE 10
const int MHD_gtls_extensions_size = MAX_EXT_SIZE;
MHD_gtls_extension_entry MHD_gtls_extensions[MAX_EXT_SIZE] = {
GNUTLS_EXTENSION_ENTRY (GNUTLS_EXTENSION_MAX_RECORD_SIZE,
EXTENSION_TLS,
MHD_gtls_max_record_recv_params,
MHD_gtls_max_record_send_params),
GNUTLS_EXTENSION_ENTRY (GNUTLS_EXTENSION_CERT_TYPE,
EXTENSION_TLS,
MHD_gtls_cert_type_recv_params,
MHD_gtls_cert_type_send_params),
GNUTLS_EXTENSION_ENTRY (GNUTLS_EXTENSION_SERVER_NAME,
EXTENSION_APPLICATION,
MHD_gtls_server_name_recv_params,
MHD_gtls_server_name_send_params),
#ifdef ENABLE_OPRFI
GNUTLS_EXTENSION_ENTRY (GNUTLS_EXTENSION_OPAQUE_PRF_INPUT,
EXTENSION_TLS,
MHD_gtls_oprfi_recv_params,
MHD_gtls_oprfi_send_params),
#endif
{0, 0, 0, 0}
};
#define GNUTLS_EXTENSION_LOOP2(b) \
MHD_gtls_extension_entry *p; \
for(p = MHD_gtls_extensions; p->name != NULL; p++) { b ; }
#define GNUTLS_EXTENSION_LOOP(a) \
GNUTLS_EXTENSION_LOOP2( if(p->type == type) { a; break; } )
/* EXTENSION functions */
MHD_gtls_ext_recv_func
MHD_gtls_ext_func_recv (uint16_t type, MHD_gtls_ext_parse_type_t parse_type)
{
MHD_gtls_ext_recv_func ret = NULL;
GNUTLS_EXTENSION_LOOP (if
(parse_type == EXTENSION_ANY
|| p->parse_type == parse_type) ret =
p->MHD_gnutls_ext_func_recv);
return ret;
}
MHD_gtls_ext_send_func
MHD_gtls_ext_func_send (uint16_t type)
{
MHD_gtls_ext_send_func ret = NULL;
GNUTLS_EXTENSION_LOOP (ret = p->MHD_gnutls_ext_func_send);
return ret;
}
const char *
MHD_gtls_extension_get_name (uint16_t type)
{
const char *ret = NULL;
/* avoid prefix */
GNUTLS_EXTENSION_LOOP (ret = p->name + sizeof ("GNUTLS_EXTENSION_") - 1);
return ret;
}
/* Checks if the extension we just received is one of the
* requested ones. Otherwise it's a fatal error.
*/
static int
MHD__gnutls_extension_list_check (MHD_gtls_session_t session, uint16_t type)
{
#if MHD_DEBUG_TLS
if (session->security_parameters.entity == GNUTLS_CLIENT)
{
int i;
for (i = 0; i < session->internals.extensions_sent_size; i++)
{
if (type == session->internals.extensions_sent[i])
return 0; /* ok found */
}
return GNUTLS_E_RECEIVED_ILLEGAL_EXTENSION;
}
#endif
return 0;
}
int
MHD_gtls_parse_extensions (MHD_gtls_session_t session,
MHD_gtls_ext_parse_type_t parse_type,
const opaque * data, int data_size)
{
int next, ret;
int pos = 0;
uint16_t type;
const opaque *sdata;
MHD_gtls_ext_recv_func ext_recv;
uint16_t size;
#if MHD_DEBUG_TLS
int i;
if (session->security_parameters.entity == GNUTLS_CLIENT)
for (i = 0; i < session->internals.extensions_sent_size; i++)
{
MHD__gnutls_debug_log ("EXT[%d]: expecting extension '%s'\n",
session,
MHD_gtls_extension_get_name
(session->internals.extensions_sent[i]));
}
#endif
DECR_LENGTH_RET (data_size, 2, 0);
next = MHD_gtls_read_uint16 (data);
pos += 2;
DECR_LENGTH_RET (data_size, next, 0);
do
{
DECR_LENGTH_RET (next, 2, 0);
type = MHD_gtls_read_uint16 (&data[pos]);
pos += 2;
MHD__gnutls_debug_log ("EXT[%x]: Received extension '%s/%d'\n", session,
MHD_gtls_extension_get_name (type), type);
if ((ret = MHD__gnutls_extension_list_check (session, type)) < 0)
{
MHD_gnutls_assert ();
return ret;
}
DECR_LENGTH_RET (next, 2, 0);
size = MHD_gtls_read_uint16 (&data[pos]);
pos += 2;
DECR_LENGTH_RET (next, size, 0);
sdata = &data[pos];
pos += size;
ext_recv = MHD_gtls_ext_func_recv (type, parse_type);
if (ext_recv == NULL)
continue;
if ((ret = ext_recv (session, sdata, size)) < 0)
{
MHD_gnutls_assert ();
return ret;
}
}
while (next > 2);
return 0;
}
/* Adds the extension we want to send in the extensions list.
* This list is used to check whether the (later) received
* extensions are the ones we requested.
*/
static void
MHD__gnutls_extension_list_add (MHD_gtls_session_t session, uint16_t type)
{
#if MHD_DEBUG_TLS
if (session->security_parameters.entity == GNUTLS_CLIENT)
{
if (session->internals.extensions_sent_size < MAX_EXT_TYPES)
{
session->internals.extensions_sent[session->
internals.extensions_sent_size] =
type;
session->internals.extensions_sent_size++;
}
else
{
MHD__gnutls_debug_log ("extensions: Increase MAX_EXT_TYPES\n");
}
}
#endif
}
int
MHD_gtls_gen_extensions (MHD_gtls_session_t session, opaque * data,
size_t data_size)
{
int size;
uint16_t pos = 0;
opaque *sdata;
int sdata_size;
MHD_gtls_ext_send_func ext_send;
MHD_gtls_extension_entry *p;
if (data_size < 2)
{
MHD_gnutls_assert ();
return GNUTLS_E_INTERNAL_ERROR;
}
/* allocate enough data for each extension.
*/
sdata_size = data_size;
sdata = MHD_gnutls_malloc (sdata_size);
if (sdata == NULL)
{
MHD_gnutls_assert ();
return GNUTLS_E_MEMORY_ERROR;
}
pos += 2;
for (p = MHD_gtls_extensions; p->name != NULL; p++)
{
ext_send = MHD_gtls_ext_func_send (p->type);
if (ext_send == NULL)
continue;
size = ext_send (session, sdata, sdata_size);
if (size > 0)
{
if (data_size < pos + (size_t) size + 4)
{
MHD_gnutls_assert ();
MHD_gnutls_free (sdata);
return GNUTLS_E_INTERNAL_ERROR;
}
/* write extension type */
MHD_gtls_write_uint16 (p->type, &data[pos]);
pos += 2;
/* write size */
MHD_gtls_write_uint16 (size, &data[pos]);
pos += 2;
memcpy (&data[pos], sdata, size);
pos += size;
/* add this extension to the extension list
*/
MHD__gnutls_extension_list_add (session, p->type);
MHD__gnutls_debug_log ("EXT[%x]: Sending extension %s\n", session,
MHD_gtls_extension_get_name (p->type));
}
else if (size < 0)
{
MHD_gnutls_assert ();
MHD_gnutls_free (sdata);
return size;
}
}
size = pos;
pos -= 2; /* remove the size of the size header! */
MHD_gtls_write_uint16 (pos, data);
if (size == 2)
{ /* empty */
size = 0;
}
MHD_gnutls_free (sdata);
return size;
}
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