| /* |
| * 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" |
| #include "cipher_types.h" |
| |
| 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 /* */ |
| }; |