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/*
* Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
* Free Software Foundation, Inc.
*
* Author: Nikos Mavrogiannopoulos, Simon Josefsson
*
* 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 "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 <ext_srp.h>
#include <ext_session_ticket.h>
#include <ext_safe_renegotiation.h>
#include <ext_signature.h>
#include <ext_safe_renegotiation.h>
#include <gnutls_num.h>
typedef struct
{
const char *name;
uint16_t type;
gnutls_ext_parse_type_t parse_type;
/* this function must return 0 when Not Applicable
* size of extension data if ok
* < 0 on other error.
*/
gnutls_ext_recv_func recv_func;
/* this function must return 0 when Not Applicable
* size of extension data if ok
* GNUTLS_E_INT_RET_0 if extension data size is zero
* < 0 on other error.
*/
gnutls_ext_send_func send_func;
} gnutls_extension_entry;
static size_t extfunc_size = 0;
static gnutls_extension_entry *extfunc = NULL;
static gnutls_ext_recv_func
_gnutls_ext_func_recv (uint16_t type, gnutls_ext_parse_type_t parse_type)
{
size_t i;
for (i = 0; i < extfunc_size; i++)
if (extfunc[i].type == type)
if (parse_type == GNUTLS_EXT_ANY || extfunc[i].parse_type == parse_type)
return extfunc[i].recv_func;
return NULL;
}
static const char *
_gnutls_extension_get_name (uint16_t type)
{
size_t i;
for (i = 0; i < extfunc_size; i++)
if (extfunc[i].type == type)
return extfunc[i].name;
return NULL;
}
/* Checks if the extension we just received is one of the
* requested ones. Otherwise it's a fatal error.
*/
static int
_gnutls_extension_list_check (gnutls_session_t session, uint16_t type)
{
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;
}
return 0;
}
int
_gnutls_parse_extensions (gnutls_session_t session,
gnutls_ext_parse_type_t parse_type,
const opaque * data, int data_size)
{
int next, ret;
int pos = 0;
uint16_t type;
const opaque *sdata;
gnutls_ext_recv_func ext_recv;
uint16_t size;
#ifdef DEBUG
int i;
if (session->security_parameters.entity == GNUTLS_CLIENT)
for (i = 0; i < session->internals.extensions_sent_size; i++)
{
_gnutls_debug_log ("EXT[%d]: expecting extension '%s'\n",
session,
_gnutls_extension_get_name
(session->internals.extensions_sent[i]));
}
#endif
DECR_LENGTH_RET (data_size, 2, 0);
next = _gnutls_read_uint16 (data);
pos += 2;
DECR_LENGTH_RET (data_size, next, 0);
do
{
DECR_LENGTH_RET (next, 2, 0);
type = _gnutls_read_uint16 (&data[pos]);
pos += 2;
_gnutls_debug_log ("EXT[%p]: Found extension '%s/%d'\n", session,
_gnutls_extension_get_name (type), type);
if ((ret = _gnutls_extension_list_check (session, type)) < 0)
{
gnutls_assert ();
return ret;
}
DECR_LENGTH_RET (next, 2, 0);
size = _gnutls_read_uint16 (&data[pos]);
pos += 2;
DECR_LENGTH_RET (next, size, 0);
sdata = &data[pos];
pos += size;
ext_recv = _gnutls_ext_func_recv (type, parse_type);
if (ext_recv == NULL)
continue;
if ((ret = ext_recv (session, sdata, size)) < 0)
{
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.
*/
void
_gnutls_extension_list_add (gnutls_session_t session, uint16_t type)
{
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
{
_gnutls_debug_log ("extensions: Increase MAX_EXT_TYPES\n");
}
}
}
int
_gnutls_gen_extensions (gnutls_session_t session, opaque * data,
size_t data_size)
{
int size;
uint16_t pos = 0;
opaque *sdata;
size_t sdata_size;
size_t i;
if (data_size < 2)
{
gnutls_assert ();
return GNUTLS_E_INTERNAL_ERROR;
}
/* allocate enough data for each extension.
*/
sdata_size = data_size;
sdata = gnutls_malloc (sdata_size);
if (sdata == NULL)
{
gnutls_assert ();
return GNUTLS_E_MEMORY_ERROR;
}
pos += 2;
for (i = 0; i < extfunc_size; i++)
{
gnutls_extension_entry *p = &extfunc[i];
if (p->send_func == NULL)
continue;
size = p->send_func (session, sdata, sdata_size);
if (size > 0 || size == GNUTLS_E_INT_RET_0)
{
if (size == GNUTLS_E_INT_RET_0)
size = 0;
if (data_size < pos + (size_t) size + 4)
{
gnutls_assert ();
gnutls_free (sdata);
return GNUTLS_E_INTERNAL_ERROR;
}
/* write extension type */
_gnutls_write_uint16 (p->type, &data[pos]);
pos += 2;
/* write size */
_gnutls_write_uint16 (size, &data[pos]);
pos += 2;
memcpy (&data[pos], sdata, size);
pos += size;
/* add this extension to the extension list
*/
_gnutls_extension_list_add (session, p->type);
_gnutls_debug_log ("EXT[%p]: Sending extension %s\n",
session, p->name);
}
else if (size < 0)
{
gnutls_assert ();
gnutls_free (sdata);
return size;
}
}
size = pos;
pos -= 2; /* remove the size of the size header! */
_gnutls_write_uint16 (pos, data);
if (size == 2)
{ /* empty */
size = 0;
}
gnutls_free (sdata);
return size;
}
int
_gnutls_ext_init (void)
{
int ret;
ret = gnutls_ext_register (GNUTLS_EXTENSION_MAX_RECORD_SIZE,
"MAX_RECORD_SIZE",
GNUTLS_EXT_TLS,
_gnutls_max_record_recv_params,
_gnutls_max_record_send_params);
if (ret != GNUTLS_E_SUCCESS)
return ret;
ret = gnutls_ext_register (GNUTLS_EXTENSION_CERT_TYPE,
"CERT_TYPE",
GNUTLS_EXT_TLS,
_gnutls_cert_type_recv_params,
_gnutls_cert_type_send_params);
if (ret != GNUTLS_E_SUCCESS)
return ret;
ret = gnutls_ext_register (GNUTLS_EXTENSION_SERVER_NAME,
"SERVER_NAME",
GNUTLS_EXT_APPLICATION,
_gnutls_server_name_recv_params,
_gnutls_server_name_send_params);
if (ret != GNUTLS_E_SUCCESS)
return ret;
ret = gnutls_ext_register (GNUTLS_EXTENSION_SAFE_RENEGOTIATION,
"SAFE_RENEGOTIATION",
GNUTLS_EXT_RESUMED,
_gnutls_safe_renegotiation_recv_params,
_gnutls_safe_renegotiation_send_params);
if (ret != GNUTLS_E_SUCCESS)
return ret;
#ifdef ENABLE_OPRFI
ret = gnutls_ext_register (GNUTLS_EXTENSION_OPAQUE_PRF_INPUT,
"OPAQUE_PRF_INPUT",
GNUTLS_EXT_TLS,
_gnutls_oprfi_recv_params,
_gnutls_oprfi_send_params);
if (ret != GNUTLS_E_SUCCESS)
return ret;
#endif
#ifdef ENABLE_SRP
ret = gnutls_ext_register (GNUTLS_EXTENSION_SRP,
"SRP",
GNUTLS_EXT_TLS,
_gnutls_srp_recv_params,
_gnutls_srp_send_params);
if (ret != GNUTLS_E_SUCCESS)
return ret;
#endif
#ifdef ENABLE_SESSION_TICKET
ret = gnutls_ext_register (GNUTLS_EXTENSION_SESSION_TICKET,
"SESSION_TICKET",
GNUTLS_EXT_TLS,
_gnutls_session_ticket_recv_params,
_gnutls_session_ticket_send_params);
if (ret != GNUTLS_E_SUCCESS)
return ret;
#endif
ret = gnutls_ext_register (GNUTLS_EXTENSION_SIGNATURE_ALGORITHMS,
"SIGNATURE_ALGORITHMS",
GNUTLS_EXT_TLS,
_gnutls_signature_algorithm_recv_params,
_gnutls_signature_algorithm_send_params);
if (ret != GNUTLS_E_SUCCESS)
return ret;
return GNUTLS_E_SUCCESS;
}
void
_gnutls_ext_deinit (void)
{
gnutls_free (extfunc);
extfunc = NULL;
extfunc_size = 0;
}
/**
* gnutls_ext_register - Register a handler for a TLS extension
* @type: the 16-bit integer referring to the extension type
* @name: human printable name of the extension used for debugging
* @parse_type: either #GNUTLS_EXT_TLS or %GNUTLS_EXT_APPLICATION.
* @recv_func: a function to receive extension data
* @send_func: a function to send extension data
*
* This function is used to register a new TLS extension handler.
*
* Returns: %GNUTLS_E_SUCCESS on success, or an error code.
*
* Since: 2.6.0
**/
int
gnutls_ext_register (int type,
const char *name,
gnutls_ext_parse_type_t parse_type,
gnutls_ext_recv_func recv_func,
gnutls_ext_send_func send_func)
{
gnutls_extension_entry *p;
p = gnutls_realloc (extfunc, sizeof (*extfunc) * (extfunc_size + 1));
if (!p)
{
gnutls_assert ();
return GNUTLS_E_MEMORY_ERROR;
}
extfunc = p;
extfunc[extfunc_size].type = type;
extfunc[extfunc_size].name = name;
extfunc[extfunc_size].parse_type = parse_type;
extfunc[extfunc_size].recv_func = recv_func;
extfunc[extfunc_size].send_func = send_func;
extfunc_size++;
return GNUTLS_E_SUCCESS;
}
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