D-Modem/pjproject-2.11.1/third_party/srtp/crypto/hash/null_auth.c
2021-10-29 14:41:03 -04:00

160 lines
5.1 KiB
C

/*
* null_auth.c
*
* implements the do-nothing auth algorithm
*
* David A. McGrew
* Cisco Systems, Inc.
*
*/
/*
*
* Copyright (c) 2001-2017, Cisco Systems, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 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.
*
* Neither the name of the Cisco Systems, Inc. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT HOLDERS OR CONTRIBUTORS 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.
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "null_auth.h"
#include "err.h" /* for srtp_debug */
#include "alloc.h"
/* null_auth uses the auth debug module */
extern srtp_debug_module_t srtp_mod_auth;
static srtp_err_status_t srtp_null_auth_alloc (srtp_auth_t **a, int key_len, int out_len)
{
extern const srtp_auth_type_t srtp_null_auth;
uint8_t *pointer;
debug_print(srtp_mod_auth, "allocating auth func with key length %d", key_len);
debug_print(srtp_mod_auth, " tag length %d", out_len);
/* allocate memory for auth and srtp_null_auth_ctx_t structures */
pointer = (uint8_t*)srtp_crypto_alloc(sizeof(srtp_null_auth_ctx_t) + sizeof(srtp_auth_t));
if (pointer == NULL) {
return srtp_err_status_alloc_fail;
}
/* set pointers */
*a = (srtp_auth_t*)pointer;
(*a)->type = &srtp_null_auth;
(*a)->state = pointer + sizeof(srtp_auth_t);
(*a)->out_len = out_len;
(*a)->prefix_len = out_len;
(*a)->key_len = key_len;
return srtp_err_status_ok;
}
static srtp_err_status_t srtp_null_auth_dealloc (srtp_auth_t *a)
{
extern const srtp_auth_type_t srtp_null_auth;
/* zeroize entire state*/
octet_string_set_to_zero(a, sizeof(srtp_null_auth_ctx_t) + sizeof(srtp_auth_t));
/* free memory */
srtp_crypto_free(a);
return srtp_err_status_ok;
}
static srtp_err_status_t srtp_null_auth_init (void *statev, const uint8_t *key, int key_len)
{
/* srtp_null_auth_ctx_t *state = (srtp_null_auth_ctx_t *)statev; */
/* accept any length of key, and do nothing */
return srtp_err_status_ok;
}
static srtp_err_status_t srtp_null_auth_compute (void *statev, const uint8_t *message,
int msg_octets, int tag_len, uint8_t *result)
{
/* srtp_null_auth_ctx_t *state = (srtp_null_auth_ctx_t *)statev; */
return srtp_err_status_ok;
}
static srtp_err_status_t srtp_null_auth_update (void *statev, const uint8_t *message,
int msg_octets)
{
/* srtp_null_auth_ctx_t *state = (srtp_null_auth_ctx_t *)statev; */
return srtp_err_status_ok;
}
static srtp_err_status_t srtp_null_auth_start (void *statev)
{
/* srtp_null_auth_ctx_t *state = (srtp_null_auth_ctx_t *)statev; */
return srtp_err_status_ok;
}
/*
* srtp_auth_type_t - defines description, test case, and null_auth
* metaobject
*/
/* begin test case 0 */
static const srtp_auth_test_case_t srtp_null_auth_test_case_0 = {
0, /* octets in key */
NULL, /* key */
0, /* octets in data */
NULL, /* data */
0, /* octets in tag */
NULL, /* tag */
NULL /* pointer to next testcase */
};
/* end test case 0 */
static const char srtp_null_auth_description[] = "null authentication function";
const srtp_auth_type_t srtp_null_auth = {
srtp_null_auth_alloc,
srtp_null_auth_dealloc,
srtp_null_auth_init,
srtp_null_auth_compute,
srtp_null_auth_update,
srtp_null_auth_start,
srtp_null_auth_description,
&srtp_null_auth_test_case_0,
SRTP_NULL_AUTH
};