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/*
* Copyright (C) 2007 Free Software Foundation
*
* Author: 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
*
*/
/* Implementation of Opaque PRF Input:
* http://tools.ietf.org/id/draft-rescorla-tls-opaque-prf-input-00.txt
*
*/
#include "MHD_config.h"
#include <ext_oprfi.h>
#include <gnutls_errors.h>
#include <gnutls_num.h>
static int
oprfi_recv_server (mhd_gtls_session_t session,
const opaque * data, size_t _data_size)
{
ssize_t data_size = _data_size;
uint16_t len;
if (!session->security_parameters.extensions.oprfi_cb)
{
gnutls_assert ();
return 0;
}
DECR_LEN (data_size, 2);
len = mhd_gtls_read_uint16 (data);
data += 2;
if (len != data_size)
{
gnutls_assert ();
return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
}
/* Store incoming data. */
session->security_parameters.extensions.oprfi_client_len = len;
session->security_parameters.extensions.oprfi_client = gnutls_malloc (len);
if (!session->security_parameters.extensions.oprfi_client)
{
gnutls_assert ();
return GNUTLS_E_MEMORY_ERROR;
}
memcpy (session->security_parameters.extensions.oprfi_client, data, len);
return 0;
}
static int
oprfi_recv_client (mhd_gtls_session_t session,
const opaque * data, size_t _data_size)
{
ssize_t data_size = _data_size;
uint16_t len;
if (session->security_parameters.extensions.oprfi_client == NULL)
{
gnutls_assert ();
return 0;
}
DECR_LEN (data_size, 2);
len = mhd_gtls_read_uint16 (data);
data += 2;
if (len != data_size)
{
gnutls_assert ();
return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
}
if (len != session->security_parameters.extensions.oprfi_client_len)
{
gnutls_assert ();
return GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER;
}
/* Store incoming data. */
session->security_parameters.extensions.oprfi_server_len = len;
session->security_parameters.extensions.oprfi_server = gnutls_malloc (len);
if (!session->security_parameters.extensions.oprfi_server)
{
gnutls_assert ();
return GNUTLS_E_MEMORY_ERROR;
}
memcpy (session->security_parameters.extensions.oprfi_server, data, len);
return 0;
}
int
mhd_gtls_oprfi_recv_params (mhd_gtls_session_t session,
const opaque * data, size_t data_size)
{
#if MHD_DEBUG_TLS
if (session->security_parameters.entity == GNUTLS_CLIENT)
return oprfi_recv_client (session, data, data_size);
else
#endif
return oprfi_recv_server (session, data, data_size);
}
static int
oprfi_send_client (mhd_gtls_session_t session, opaque * data,
size_t _data_size)
{
opaque *p = data;
ssize_t data_size = _data_size;
int oprf_size = session->security_parameters.extensions.oprfi_client_len;
if (oprf_size == 0)
return 0;
DECR_LENGTH_RET (data_size, 2, GNUTLS_E_SHORT_MEMORY_BUFFER);
mhd_gtls_write_uint16 (oprf_size, p);
p += 2;
DECR_LENGTH_RET (data_size, oprf_size, GNUTLS_E_SHORT_MEMORY_BUFFER);
memcpy (p, session->security_parameters.extensions.oprfi_client, oprf_size);
return 2 + oprf_size;
}
static int
oprfi_send_server (mhd_gtls_session_t session, opaque * data,
size_t _data_size)
{
opaque *p = data;
int ret;
ssize_t data_size = _data_size;
if (!session->security_parameters.extensions.oprfi_client ||
!session->security_parameters.extensions.oprfi_cb)
return 0;
/* Allocate buffer for outgoing data. */
session->security_parameters.extensions.oprfi_server_len =
session->security_parameters.extensions.oprfi_client_len;
session->security_parameters.extensions.oprfi_server =
gnutls_malloc (session->security_parameters.extensions.oprfi_server_len);
if (!session->security_parameters.extensions.oprfi_server)
{
gnutls_assert ();
return GNUTLS_E_MEMORY_ERROR;
}
/* Get outgoing data. */
ret = session->security_parameters.extensions.oprfi_cb
(session, session->security_parameters.extensions.oprfi_userdata,
session->security_parameters.extensions.oprfi_client_len,
session->security_parameters.extensions.oprfi_client,
session->security_parameters.extensions.oprfi_server);
if (ret < 0)
{
gnutls_assert ();
gnutls_free (session->security_parameters.extensions.oprfi_server);
return ret;
}
DECR_LENGTH_RET (data_size, 2, GNUTLS_E_SHORT_MEMORY_BUFFER);
mhd_gtls_write_uint16 (session->security_parameters.
extensions.oprfi_server_len, p);
p += 2;
DECR_LENGTH_RET (data_size,
session->security_parameters.extensions.oprfi_server_len,
GNUTLS_E_SHORT_MEMORY_BUFFER);
memcpy (p, session->security_parameters.extensions.oprfi_server,
session->security_parameters.extensions.oprfi_server_len);
return 2 + session->security_parameters.extensions.oprfi_server_len;
}
int
mhd_gtls_oprfi_send_params (mhd_gtls_session_t session,
opaque * data, size_t data_size)
{
#if MHD_DEBUG_TLS
if (session->security_parameters.entity == GNUTLS_CLIENT)
return oprfi_send_client (session, data, data_size);
else
#endif
return oprfi_send_server (session, data, data_size);
}
/**
* MHD_gtls_oprfi_enable_client:
* @session: is a #mhd_gtls_session_t structure.
* @len: length of Opaque PRF data to use in client.
* @data: Opaque PRF data to use in client.
*
* Request that the client should attempt to negotiate the Opaque PRF
* Input TLS extension, using the given data as the client's Opaque
* PRF input.
*
* The data is copied into the session context after this call, so you
* may de-allocate it immediately after calling this function.
**/
void
MHD_gtls_oprfi_enable_client (mhd_gtls_session_t session,
size_t len, unsigned char *data)
{
session->security_parameters.extensions.oprfi_client_len = len;
session->security_parameters.extensions.oprfi_client = data;
}
/**
* MHD_gtls_oprfi_enable_server:
* @session: is a #mhd_gtls_session_t structure.
* @cb: function pointer to Opaque PRF extension server callback.
* @userdata: hook passed to callback function for passing application state.
*
* Request that the server should attempt to accept the Opaque PRF
* Input TLS extension. If the client requests the extension, the
* provided callback @cb will be invoked. The callback must have the
* following prototype:
*
* int callback (mhd_gtls_session_t session, void *userdata,
* size_t oprfi_len, const unsigned char *in_oprfi,
* unsigned char *out_oprfi);
*
* The callback can inspect the client-provided data in the input
* parameters, and specify its own opaque prf input data in the output
* variable. The function must return 0 on success, otherwise the
* handshake will be aborted.
**/
void
MHD_gtls_oprfi_enable_server (mhd_gtls_session_t session,
gnutls_oprfi_callback_func cb, void *userdata)
{
session->security_parameters.extensions.oprfi_cb = cb;
session->security_parameters.extensions.oprfi_userdata = userdata;
}
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