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/*
* Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Niels Provos.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* handle_value_response:
* receive a VALUE_RESPONSE packet; return -1 on failure, 0 on success
*
*/
#ifndef lint
static char rcsid[] = "$Id: handle_value_response.c,v 1.3 1997/09/02 17:26:41 provos Exp $";
#endif
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "config.h"
#include "photuris.h"
#include "packets.h"
#include "state.h"
#include "cookie.h"
#include "buffer.h"
#include "scheme.h"
#include "packet.h"
#include "schedule.h"
#include "exchange.h"
#include "secrets.h"
#include "spi.h"
#include "errlog.h"
#ifdef DEBUG
#include "config.h"
#endif
int
handle_value_response(u_char *packet, int size, char *address,
char *local_address)
{
struct value_response *header;
struct stateob *st;
mpz_t test;
u_int8_t *p;
u_int16_t i, asize;
if (size < VALUE_RESPONSE_MIN)
return -1; /* packet too small */
header = (struct value_response *) packet;
st = state_find_cookies(address, header->icookie, header->rcookie);
if (st == NULL)
return -1; /* Silently discard */
if (st->phase != VALUE_REQUEST)
return -1; /* We don't want this packet */
/* Check exchange value - XXX doesn't check long form */
p = VALUE_RESPONSE_VALUE(header);
asize = VALUE_RESPONSE_MIN + varpre2octets(p);
p += varpre2octets(p);
if (asize >= size)
return -1; /* Exchange value too big */
/* Check attributes */
i = 0;
while(asize + i < size)
i += p[i+1] + 2;
if (asize + i != size)
return -1; /* attributes dont match udp length */
/* Now check the exchange value for defects */
mpz_init_set_varpre(test, VALUE_RESPONSE_VALUE(header));
if (!exchange_check_value(test, st->generator, st->modulus)) {
mpz_clear(test);
return 0;
}
mpz_clear(test);
/* Fill the state object */
st->uSPIoattrib = calloc(i, sizeof(u_int8_t));
if (st->uSPIoattrib == NULL) {
state_value_reset(st);
state_unlink(st);
return -1;
}
bcopy(p, st->uSPIoattrib, i);
st->uSPIoattribsize = i;
#ifdef DEBUG
{
int i = BUFFER_SIZE;
bin2hex(buffer, &i, VALUE_RESPONSE_VALUE(header),
varpre2octets(VALUE_RESPONSE_VALUE(header)));
printf("Got exchange value 0x%s\n", buffer);
}
#endif
/* Set exchange value */
st->texchangesize = varpre2octets(VALUE_RESPONSE_VALUE(header));
st->texchange = calloc(st->texchangesize, sizeof(u_int8_t));
if (st->texchange == NULL) {
log_error(1, "calloc() in handle_value_response()");
return -1;
}
bcopy(VALUE_RESPONSE_VALUE(header), st->texchange, st->texchangesize);
/* Compute the shared secret now */
compute_shared_secret(st, &(st->shared), &(st->sharedsize));
#ifdef DEBUG
{
int i = BUFFER_SIZE;
bin2hex(buffer, &i, st->shared, st->sharedsize);
printf("Shared secret is: 0x%s\n", buffer);
}
#endif
/* Create SPI + choice of attributes */
if (make_spi(st, local_address, st->oSPI, &(st->olifetime),
&(st->oSPIattrib), &(st->oSPIattribsize)) == -1) {
log_error(0, "make_spi() in handle_value_response()");
return -1;
}
/* Initialize Privacy Keys from Exchange Values */
init_privacy_key(st, 0); /* User -> Owner direction */
init_privacy_key(st, 1); /* Owner -> User direction */
packet_size = PACKET_BUFFER_SIZE;
if (photuris_identity_request(st, packet_buffer, &packet_size) == -1)
return -1;
packet_save(st, packet_buffer, packet_size);
send_packet();
st->retries = 0;
st->phase = IDENTITY_REQUEST;
schedule_remove(TIMEOUT, st->icookie);
schedule_insert(TIMEOUT, retrans_timeout, st->icookie, COOKIE_SIZE);
return 0;
}
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