1 /*
2 * auth.c
3 *
4 * some bookkeeping functions for authentication functions
5 *
6 * David A. McGrew
7 * Cisco Systems, Inc.
8 */
9
10 /*
11 *
12 * Copyright (c) 2001-2006, Cisco Systems, Inc.
13 * All rights reserved.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 *
19 * Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 *
22 * Redistributions in binary form must reproduce the above
23 * copyright notice, this list of conditions and the following
24 * disclaimer in the documentation and/or other materials provided
25 * with the distribution.
26 *
27 * Neither the name of the Cisco Systems, Inc. nor the names of its
28 * contributors may be used to endorse or promote products derived
29 * from this software without specific prior written permission.
30 *
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
34 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
35 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
36 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
37 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
38 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
41 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
42 * OF THE POSSIBILITY OF SUCH DAMAGE.
43 *
44 */
45
46 #include "auth.h"
47
48 /* the debug module for authentiation */
49
50 debug_module_t mod_auth = {
51 0, /* debugging is off by default */
52 "auth func" /* printable name for module */
53 };
54
55
56 int
auth_get_key_length(const auth_t * a)57 auth_get_key_length(const auth_t *a) {
58 return a->key_len;
59 }
60
61 int
auth_get_tag_length(const auth_t * a)62 auth_get_tag_length(const auth_t *a) {
63 return a->out_len;
64 }
65
66 int
auth_get_prefix_length(const auth_t * a)67 auth_get_prefix_length(const auth_t *a) {
68 return a->prefix_len;
69 }
70
71 int
auth_type_get_ref_count(const auth_type_t * at)72 auth_type_get_ref_count(const auth_type_t *at) {
73 return at->ref_count;
74 }
75
76 /*
77 * auth_type_self_test() tests an auth function of type ct against
78 * test cases provided in an array of values of key, data, and tag
79 * that is known to be good
80 */
81
82 /* should be big enough for most occasions */
83 #define SELF_TEST_TAG_BUF_OCTETS 32
84
85 err_status_t
auth_type_self_test(const auth_type_t * at)86 auth_type_self_test(const auth_type_t *at) {
87 auth_test_case_t *test_case = at->test_data;
88 auth_t *a;
89 err_status_t status;
90 uint8_t tag[SELF_TEST_TAG_BUF_OCTETS];
91 int i, case_num = 0;
92
93 debug_print(mod_auth, "running self-test for auth function %s",
94 at->description);
95
96 /*
97 * check to make sure that we have at least one test case, and
98 * return an error if we don't - we need to be paranoid here
99 */
100 if (test_case == NULL)
101 return err_status_cant_check;
102
103 /* loop over all test cases */
104 while (test_case != NULL) {
105
106 /* check test case parameters */
107 if (test_case->tag_length_octets > SELF_TEST_TAG_BUF_OCTETS)
108 return err_status_bad_param;
109
110 /* allocate auth */
111 status = auth_type_alloc(at, &a, test_case->key_length_octets,
112 test_case->tag_length_octets);
113 if (status)
114 return status;
115
116 /* initialize auth */
117 status = auth_init(a, test_case->key);
118 if (status) {
119 auth_dealloc(a);
120 return status;
121 }
122
123 /* zeroize tag then compute */
124 octet_string_set_to_zero(tag, test_case->tag_length_octets);
125 status = auth_compute(a, test_case->data,
126 test_case->data_length_octets, tag);
127 if (status) {
128 auth_dealloc(a);
129 return status;
130 }
131
132 debug_print(mod_auth, "key: %s",
133 octet_string_hex_string(test_case->key,
134 test_case->key_length_octets));
135 debug_print(mod_auth, "data: %s",
136 octet_string_hex_string(test_case->data,
137 test_case->data_length_octets));
138 debug_print(mod_auth, "tag computed: %s",
139 octet_string_hex_string(tag, test_case->tag_length_octets));
140 debug_print(mod_auth, "tag expected: %s",
141 octet_string_hex_string(test_case->tag,
142 test_case->tag_length_octets));
143
144 /* check the result */
145 status = err_status_ok;
146 for (i=0; i < test_case->tag_length_octets; i++)
147 if (tag[i] != test_case->tag[i]) {
148 status = err_status_algo_fail;
149 debug_print(mod_auth, "test case %d failed", case_num);
150 debug_print(mod_auth, " (mismatch at octet %d)", i);
151 }
152 if (status) {
153 auth_dealloc(a);
154 return err_status_algo_fail;
155 }
156
157 /* deallocate the auth function */
158 status = auth_dealloc(a);
159 if (status)
160 return status;
161
162 /*
163 * the auth function passed the test case, so move on to the next test
164 * case in the list; if NULL, we'll quit and return an OK
165 */
166 test_case = test_case->next_test_case;
167 ++case_num;
168 }
169
170 return err_status_ok;
171 }
172
173
174