1 /* 2 * auth.h 3 * 4 * common interface to 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 #ifndef AUTH_H 47 #define AUTH_H 48 49 #include "datatypes.h" 50 #include "err.h" /* error codes */ 51 52 typedef struct auth_type_t *auth_type_pointer; 53 typedef struct auth_t *auth_pointer_t; 54 55 typedef err_status_t (*auth_alloc_func) 56 (auth_pointer_t *ap, int key_len, int out_len); 57 58 typedef err_status_t (*auth_init_func) 59 (void *state, const uint8_t *key, int key_len); 60 61 typedef err_status_t (*auth_dealloc_func)(auth_pointer_t ap); 62 63 typedef err_status_t (*auth_compute_func) 64 (void *state, uint8_t *buffer, int octets_to_auth, 65 int tag_len, uint8_t *tag); 66 67 typedef err_status_t (*auth_update_func) 68 (void *state, uint8_t *buffer, int octets_to_auth); 69 70 typedef err_status_t (*auth_start_func)(void *state); 71 72 /* some syntactic sugar on these function types */ 73 74 #define auth_type_alloc(at, a, klen, outlen) \ 75 ((at)->alloc((a), (klen), (outlen))) 76 77 #define auth_init(a, key) \ 78 (((a)->type)->init((a)->state, (key), ((a)->key_len))) 79 80 #define auth_compute(a, buf, len, res) \ 81 (((a)->type)->compute((a)->state, (buf), (len), (a)->out_len, (res))) 82 83 #define auth_update(a, buf, len) \ 84 (((a)->type)->update((a)->state, (buf), (len))) 85 86 #define auth_start(a)(((a)->type)->start((a)->state)) 87 88 #define auth_dealloc(c) (((c)->type)->dealloc(c)) 89 90 /* functions to get information about a particular auth_t */ 91 92 int 93 auth_get_key_length(const struct auth_t *a); 94 95 int 96 auth_get_tag_length(const struct auth_t *a); 97 98 int 99 auth_get_prefix_length(const struct auth_t *a); 100 101 /* 102 * auth_test_case_t is a (list of) key/message/tag values that are 103 * known to be correct for a particular cipher. this data can be used 104 * to test an implementation in an on-the-fly self test of the 105 * correcness of the implementation. (see the auth_type_self_test() 106 * function below) 107 */ 108 109 typedef struct auth_test_case_t { 110 int key_length_octets; /* octets in key */ 111 uint8_t *key; /* key */ 112 int data_length_octets; /* octets in data */ 113 uint8_t *data; /* data */ 114 int tag_length_octets; /* octets in tag */ 115 uint8_t *tag; /* tag */ 116 struct auth_test_case_t *next_test_case; /* pointer to next testcase */ 117 } auth_test_case_t; 118 119 /* auth_type_t */ 120 121 typedef struct auth_type_t { 122 auth_alloc_func alloc; 123 auth_dealloc_func dealloc; 124 auth_init_func init; 125 auth_compute_func compute; 126 auth_update_func update; 127 auth_start_func start; 128 char *description; 129 int ref_count; 130 auth_test_case_t *test_data; 131 debug_module_t *debug; 132 } auth_type_t; 133 134 typedef struct auth_t { 135 auth_type_t *type; 136 void *state; 137 int out_len; /* length of output tag in octets */ 138 int key_len; /* length of key in octets */ 139 int prefix_len; /* length of keystream prefix */ 140 } auth_t; 141 142 /* 143 * auth_type_self_test() tests an auth_type against test cases 144 * provided in an array of values of key/message/tag that is known to 145 * be good 146 */ 147 148 err_status_t 149 auth_type_self_test(const auth_type_t *at); 150 151 /* 152 * auth_type_get_ref_count(at) returns the reference count (the number 153 * of instantiations) of the auth_type_t at 154 */ 155 156 int 157 auth_type_get_ref_count(const auth_type_t *at); 158 159 #endif /* AUTH_H */ 160