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 57 auth_get_key_length(const auth_t *a) { 58 return a->key_len; 59 } 60 61 int 62 auth_get_tag_length(const auth_t *a) { 63 return a->out_len; 64 } 65 66 int 67 auth_get_prefix_length(const auth_t *a) { 68 return a->prefix_len; 69 } 70 71 int 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 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
