1/*
2 * null_auth.c
3 *
4 * implements the do-nothing auth algorithm
5 *
6 * David A. McGrew
7 * Cisco Systems, Inc.
8 *
9 */
10
11/*
12 *
13 * Copyright (c) 2001-2006, Cisco Systems, Inc.
14 * All rights reserved.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 *
20 *   Redistributions of source code must retain the above copyright
21 *   notice, this list of conditions and the following disclaimer.
22 *
23 *   Redistributions in binary form must reproduce the above
24 *   copyright notice, this list of conditions and the following
25 *   disclaimer in the documentation and/or other materials provided
26 *   with the distribution.
27 *
28 *   Neither the name of the Cisco Systems, Inc. nor the names of its
29 *   contributors may be used to endorse or promote products derived
30 *   from this software without specific prior written permission.
31 *
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
35 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
36 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
37 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
38 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
39 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
41 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
42 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
43 * OF THE POSSIBILITY OF SUCH DAMAGE.
44 *
45 */
46
47
48#include "null_auth.h"
49#include "alloc.h"
50
51/* null_auth uses the auth debug module */
52
53extern debug_module_t mod_auth;
54
55err_status_t
56null_auth_alloc(auth_t **a, int key_len, int out_len) {
57  extern auth_type_t null_auth;
58  uint8_t *pointer;
59
60  debug_print(mod_auth, "allocating auth func with key length %d", key_len);
61  debug_print(mod_auth, "                          tag length %d", out_len);
62
63  /* allocate memory for auth and null_auth_ctx_t structures */
64  pointer = (uint8_t*)crypto_alloc(sizeof(null_auth_ctx_t) + sizeof(auth_t));
65  if (pointer == NULL)
66    return err_status_alloc_fail;
67
68  /* set pointers */
69  *a = (auth_t *)pointer;
70  (*a)->type = &null_auth;
71  (*a)->state = pointer + sizeof (auth_t);
72  (*a)->out_len = out_len;
73  (*a)->prefix_len = out_len;
74  (*a)->key_len = key_len;
75
76  /* increment global count of all null_auth uses */
77  null_auth.ref_count++;
78
79  return err_status_ok;
80}
81
82err_status_t
83null_auth_dealloc(auth_t *a) {
84  extern auth_type_t null_auth;
85
86  /* zeroize entire state*/
87  octet_string_set_to_zero((uint8_t *)a,
88			   sizeof(null_auth_ctx_t) + sizeof(auth_t));
89
90  /* free memory */
91  crypto_free(a);
92
93  /* decrement global count of all null_auth uses */
94  null_auth.ref_count--;
95
96  return err_status_ok;
97}
98
99err_status_t
100null_auth_init(null_auth_ctx_t *state, const uint8_t *key, int key_len) {
101
102  /* accept any length of key, and do nothing */
103
104  return err_status_ok;
105}
106
107err_status_t
108null_auth_compute(null_auth_ctx_t *state, uint8_t *message,
109		   int msg_octets, int tag_len, uint8_t *result) {
110
111  return err_status_ok;
112}
113
114err_status_t
115null_auth_update(null_auth_ctx_t *state, uint8_t *message,
116		   int msg_octets) {
117
118  return err_status_ok;
119}
120
121err_status_t
122null_auth_start(null_auth_ctx_t *state) {
123  return err_status_ok;
124}
125
126/*
127 * auth_type_t - defines description, test case, and null_auth
128 * metaobject
129 */
130
131/* begin test case 0 */
132
133auth_test_case_t
134null_auth_test_case_0 = {
135  0,                                       /* octets in key            */
136  NULL,                                    /* key                      */
137  0,                                       /* octets in data           */
138  NULL,                                    /* data                     */
139  0,                                       /* octets in tag            */
140  NULL,                                    /* tag                      */
141  NULL                                     /* pointer to next testcase */
142};
143
144/* end test case 0 */
145
146char null_auth_description[] = "null authentication function";
147
148auth_type_t
149null_auth  = {
150  (auth_alloc_func)      null_auth_alloc,
151  (auth_dealloc_func)    null_auth_dealloc,
152  (auth_init_func)       null_auth_init,
153  (auth_compute_func)    null_auth_compute,
154  (auth_update_func)     null_auth_update,
155  (auth_start_func)      null_auth_start,
156  (char *)               null_auth_description,
157  (int)                  0,  /* instance count */
158  (auth_test_case_t *)   &null_auth_test_case_0
159};
160