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/*
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* Author: Steve Dispensa (<dispensa@phonefactor.com>)
*
* 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
*
*/
#include <gnutls_int.h>
#include <ext_safe_renegotiation.h>
#include <gnutls_errors.h>
int
_gnutls_safe_renegotiation_recv_params (gnutls_session_t session,
const opaque * data, size_t _data_size)
{
tls_ext_st *ext = &session->security_parameters.extensions;
int len = data[0];
ssize_t data_size = _data_size;
DECR_LEN (data_size, len+1 /* count the first byte and payload */);
/* It is not legal to receive this extension on a renegotiation and
* not receive it on the initial negotiation.
*/
if (session->internals.initial_negotiation_completed != 0 &&
session->internals.connection_using_safe_renegotiation == 0)
{
gnutls_assert();
return GNUTLS_E_SAFE_RENEGOTIATION_FAILED;
}
if (len > sizeof (ext->ri_extension_data))
{
gnutls_assert();
return GNUTLS_E_SAFE_RENEGOTIATION_FAILED;
}
if (len > 0)
memcpy (ext->ri_extension_data, &data[1], len);
ext->ri_extension_data_len = len;
/* "safe renegotiation received" means on *this* handshake; "connection using
* safe renegotiation" means that the initial hello received on the connection
* indicated safe renegotiation.
*/
session->internals.safe_renegotiation_received = 1;
session->internals.connection_using_safe_renegotiation = 1;
return 0;
}
int
_gnutls_safe_renegotiation_send_params (gnutls_session_t session,
opaque * data, size_t _data_size)
{
/* The format of this extension is a one-byte length of verify data followed
* by the verify data itself. Note that the length byte does not include
* itself; IOW, empty verify data is represented as a length of 0. That means
* the minimum extension is one byte: 0x00.
*/
ssize_t data_size = _data_size;
tls_ext_st *ext = &session->security_parameters.extensions;
if (session->internals.priorities.disable_safe_renegotiation != 0)
{
gnutls_assert();
return 0;
}
data[0] = 0;
/* Always offer the extension if we're a client */
if (session->internals.connection_using_safe_renegotiation ||
session->security_parameters.entity == GNUTLS_CLIENT)
{
DECR_LEN (data_size, 1);
data[0] = ext->client_verify_data_len;
DECR_LEN (data_size, ext->client_verify_data_len);
if (ext->client_verify_data_len > 0)
memcpy(&data[1],
ext->client_verify_data,
ext->client_verify_data_len);
if (session->security_parameters.entity == GNUTLS_SERVER)
{
data[0] += ext->server_verify_data_len;
DECR_LEN (data_size, ext->server_verify_data_len);
if (ext->server_verify_data_len > 0)
memcpy(&data[1 + ext->client_verify_data_len],
ext->server_verify_data,
ext->server_verify_data_len);
}
}
else
return 0;
return 1 + data[0]; /* don't forget the length byte */
}
/**
* gnutls_safe_negotiation_set_initial - Used to enable and disable initial safe renegotiation
* @session: is a #gnutls_session_t structure.
* @value: 0 to disable and 1 to enable
*
* Used to enable and disable initial safe renegotiation for the current
* session. By default it is allowed for a client to not advertise safe
* renegotiation capability but there might be cases where signalling
* a client of its insecurity by rejecting session might be beneficial.
* This option has meaning only in server side.
**/
void
gnutls_safe_negotiation_set_initial (gnutls_session_t session, int value)
{
session->internals.priorities.initial_safe_renegotiation = value;
}
/**
* gnutls_safe_negotiation_set - Used to enable and disable safe renegotiation
* @session: is a #gnutls_session_t structure.
* @value: 0 to disable and 1 to enable
*
* Used to enable and disable safe renegotiation for the current
* session. Normally you shouldn't cope with this function since the
* default (enable) is sufficient, but there might be servers that
* cannot handle or correctly handle the extension.
**/
void gnutls_safe_renegotiation_set (gnutls_session_t session, int value)
{
session->internals.priorities.unsafe_renegotiation = 1-value;
}
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