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
52typedef struct auth_type_t *auth_type_pointer;
53typedef struct auth_t      *auth_pointer_t;
54
55typedef err_status_t (*auth_alloc_func)
56     (auth_pointer_t *ap, int key_len, int out_len);
57
58typedef err_status_t (*auth_init_func)
59     (void *state, const uint8_t *key, int key_len);
60
61typedef err_status_t (*auth_dealloc_func)(auth_pointer_t ap);
62
63typedef err_status_t (*auth_compute_func)
64     (void *state, uint8_t *buffer, int octets_to_auth,
65      int tag_len, uint8_t *tag);
66
67typedef err_status_t (*auth_update_func)
68     (void *state, uint8_t *buffer, int octets_to_auth);
69
70typedef 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
92int
93auth_get_key_length(const struct auth_t *a);
94
95int
96auth_get_tag_length(const struct auth_t *a);
97
98int
99auth_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
109typedef 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
121typedef 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
134typedef 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
148err_status_t
149auth_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
156int
157auth_type_get_ref_count(const auth_type_t *at);
158
159#endif /* AUTH_H */
160