161 lines
5.1 KiB
C
161 lines
5.1 KiB
C
/*
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* null_auth.c
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*
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* implements the do-nothing auth algorithm
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*
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* David A. McGrew
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* Cisco Systems, Inc.
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*
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*/
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/*
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*
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* Copyright (c) 2001-2017, Cisco Systems, Inc.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials provided
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* with the distribution.
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*
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* Neither the name of the Cisco Systems, Inc. nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#include "null_auth.h"
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#include "err.h" /* for srtp_debug */
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#include "alloc.h"
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/* null_auth uses the auth debug module */
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extern srtp_debug_module_t srtp_mod_auth;
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static srtp_err_status_t srtp_null_auth_alloc (srtp_auth_t **a, int key_len, int out_len)
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{
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extern const srtp_auth_type_t srtp_null_auth;
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uint8_t *pointer;
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debug_print(srtp_mod_auth, "allocating auth func with key length %d", key_len);
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debug_print(srtp_mod_auth, " tag length %d", out_len);
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/* allocate memory for auth and srtp_null_auth_ctx_t structures */
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pointer = (uint8_t*)srtp_crypto_alloc(sizeof(srtp_null_auth_ctx_t) + sizeof(srtp_auth_t));
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if (pointer == NULL) {
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return srtp_err_status_alloc_fail;
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}
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/* set pointers */
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*a = (srtp_auth_t*)pointer;
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(*a)->type = &srtp_null_auth;
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(*a)->state = pointer + sizeof(srtp_auth_t);
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(*a)->out_len = out_len;
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(*a)->prefix_len = out_len;
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(*a)->key_len = key_len;
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return srtp_err_status_ok;
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}
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static srtp_err_status_t srtp_null_auth_dealloc (srtp_auth_t *a)
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{
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extern const srtp_auth_type_t srtp_null_auth;
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/* zeroize entire state*/
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octet_string_set_to_zero(a, sizeof(srtp_null_auth_ctx_t) + sizeof(srtp_auth_t));
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/* free memory */
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srtp_crypto_free(a);
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return srtp_err_status_ok;
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}
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static srtp_err_status_t srtp_null_auth_init (void *statev, const uint8_t *key, int key_len)
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{
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/* srtp_null_auth_ctx_t *state = (srtp_null_auth_ctx_t *)statev; */
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/* accept any length of key, and do nothing */
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return srtp_err_status_ok;
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}
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static srtp_err_status_t srtp_null_auth_compute (void *statev, const uint8_t *message,
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int msg_octets, int tag_len, uint8_t *result)
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{
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/* srtp_null_auth_ctx_t *state = (srtp_null_auth_ctx_t *)statev; */
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return srtp_err_status_ok;
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}
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static srtp_err_status_t srtp_null_auth_update (void *statev, const uint8_t *message,
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int msg_octets)
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{
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/* srtp_null_auth_ctx_t *state = (srtp_null_auth_ctx_t *)statev; */
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return srtp_err_status_ok;
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}
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static srtp_err_status_t srtp_null_auth_start (void *statev)
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{
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/* srtp_null_auth_ctx_t *state = (srtp_null_auth_ctx_t *)statev; */
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return srtp_err_status_ok;
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}
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/*
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* srtp_auth_type_t - defines description, test case, and null_auth
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* metaobject
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*/
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/* begin test case 0 */
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static const srtp_auth_test_case_t srtp_null_auth_test_case_0 = {
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0, /* octets in key */
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NULL, /* key */
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0, /* octets in data */
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NULL, /* data */
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0, /* octets in tag */
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NULL, /* tag */
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NULL /* pointer to next testcase */
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};
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/* end test case 0 */
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static const char srtp_null_auth_description[] = "null authentication function";
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const srtp_auth_type_t srtp_null_auth = {
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srtp_null_auth_alloc,
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srtp_null_auth_dealloc,
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srtp_null_auth_init,
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srtp_null_auth_compute,
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srtp_null_auth_update,
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srtp_null_auth_start,
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srtp_null_auth_description,
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&srtp_null_auth_test_case_0,
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SRTP_NULL_AUTH
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};
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