libSRTP
auth.h
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) 2001-2017, 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 SRTP_AUTH_H
47#define SRTP_AUTH_H
48
49#include "srtp.h"
50#include "crypto_types.h" /* for values of auth_type_id_t */
51
52#ifdef __cplusplus
53extern "C" {
54#endif
55
56typedef const struct srtp_auth_type_t *srtp_auth_type_pointer;
57typedef struct srtp_auth_t *srtp_auth_pointer_t;
58
59typedef srtp_err_status_t (*srtp_auth_alloc_func)(srtp_auth_pointer_t *ap,
60 int key_len,
61 int out_len);
62
63typedef srtp_err_status_t (*srtp_auth_init_func)(void *state,
64 const uint8_t *key,
65 int key_len);
66
67typedef srtp_err_status_t (*srtp_auth_dealloc_func)(srtp_auth_pointer_t ap);
68
69typedef srtp_err_status_t (*srtp_auth_compute_func)(void *state,
70 const uint8_t *buffer,
71 int octets_to_auth,
72 int tag_len,
73 uint8_t *tag);
74
75typedef srtp_err_status_t (*srtp_auth_update_func)(void *state,
76 const uint8_t *buffer,
77 int octets_to_auth);
78
79typedef srtp_err_status_t (*srtp_auth_start_func)(void *state);
80
81/* some syntactic sugar on these function types */
82#define srtp_auth_type_alloc(at, a, klen, outlen) \
83 ((at)->alloc((a), (klen), (outlen)))
84
85#define srtp_auth_init(a, key) \
86 (((a)->type)->init((a)->state, (key), ((a)->key_len)))
87
88#define srtp_auth_compute(a, buf, len, res) \
89 (((a)->type)->compute((a)->state, (buf), (len), (a)->out_len, (res)))
90
91#define srtp_auth_update(a, buf, len) \
92 (((a)->type)->update((a)->state, (buf), (len)))
93
94#define srtp_auth_start(a) (((a)->type)->start((a)->state))
95
96#define srtp_auth_dealloc(c) (((c)->type)->dealloc(c))
97
98/* functions to get information about a particular auth_t */
99int srtp_auth_get_key_length(const struct srtp_auth_t *a);
100
101int srtp_auth_get_tag_length(const struct srtp_auth_t *a);
102
103int srtp_auth_get_prefix_length(const struct srtp_auth_t *a);
104
105/*
106 * srtp_auth_test_case_t is a (list of) key/message/tag values that are
107 * known to be correct for a particular cipher. this data can be used
108 * to test an implementation in an on-the-fly self test of the
109 * correctness of the implementation. (see the srtp_auth_type_self_test()
110 * function below)
111 */
112typedef struct srtp_auth_test_case_t {
113 int key_length_octets; /* octets in key */
114 const uint8_t *key; /* key */
115 int data_length_octets; /* octets in data */
116 const uint8_t *data; /* data */
117 int tag_length_octets; /* octets in tag */
118 const uint8_t *tag; /* tag */
119 const struct srtp_auth_test_case_t
120 *next_test_case; /* pointer to next testcase */
122
123/* srtp_auth_type_t */
124typedef struct srtp_auth_type_t {
125 srtp_auth_alloc_func alloc;
126 srtp_auth_dealloc_func dealloc;
127 srtp_auth_init_func init;
128 srtp_auth_compute_func compute;
129 srtp_auth_update_func update;
130 srtp_auth_start_func start;
131 const char *description;
132 const srtp_auth_test_case_t *test_data;
135
136typedef struct srtp_auth_t {
137 const srtp_auth_type_t *type;
138 void *state;
139 int out_len; /* length of output tag in octets */
140 int key_len; /* length of key in octets */
141 int prefix_len; /* length of keystream prefix */
143
144/*
145 * srtp_auth_type_self_test() tests an auth_type against test cases
146 * provided in an array of values of key/message/tag that is known to
147 * be good
148 */
149srtp_err_status_t srtp_auth_type_self_test(const srtp_auth_type_t *at);
150
151/*
152 * srtp_auth_type_test() tests an auth_type against external test cases
153 * provided in an array of values of key/message/tag that is known to
154 * be good
155 */
156srtp_err_status_t srtp_auth_type_test(const srtp_auth_type_t *at,
157 const srtp_auth_test_case_t *test_data);
158
159/*
160 * srtp_replace_auth_type(ct, id)
161 *
162 * replaces srtp's kernel's auth type implementation for the auth_type id
163 * with a new one passed in externally. The new auth type must pass all the
164 * existing auth_type's self tests as well as its own.
165 */
166srtp_err_status_t srtp_replace_auth_type(const srtp_auth_type_t *ct,
168
169#ifdef __cplusplus
170}
171#endif
172
173#endif /* SRTP_AUTH_H */
srtp_err_status_t
srtp_err_status_t defines error codes.
Definition: srtp.h:164
uint32_t srtp_auth_type_id_t
An srtp_auth_type_id_t is an identifier for a particular authentication function.
Definition: srtp.h:154
Definition: auth.h:136
Definition: auth.h:112
Definition: auth.h:124