libSRTP  2.1.0-pre
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) 2001-2006, 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 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
53 extern "C" {
54 #endif
55 
56 typedef const struct srtp_auth_type_t *srtp_auth_type_pointer;
57 typedef struct srtp_auth_t *srtp_auth_pointer_t;
58 
59 typedef srtp_err_status_t (*srtp_auth_alloc_func)
60  (srtp_auth_pointer_t *ap, int key_len, int out_len);
61 
62 typedef srtp_err_status_t (*srtp_auth_init_func)
63  (void *state, const uint8_t *key, int key_len);
64 
65 typedef srtp_err_status_t (*srtp_auth_dealloc_func)(srtp_auth_pointer_t ap);
66 
67 typedef srtp_err_status_t (*srtp_auth_compute_func)
68  (void *state, const uint8_t *buffer, int octets_to_auth,
69  int tag_len, uint8_t *tag);
70 
71 typedef srtp_err_status_t (*srtp_auth_update_func)
72  (void *state, const uint8_t *buffer, int octets_to_auth);
73 
74 typedef srtp_err_status_t (*srtp_auth_start_func)(void *state);
75 
76 /* some syntactic sugar on these function types */
77 #define srtp_auth_type_alloc(at, a, klen, outlen) \
78  ((at)->alloc((a), (klen), (outlen)))
79 
80 #define srtp_auth_init(a, key) \
81  (((a)->type)->init((a)->state, (key), ((a)->key_len)))
82 
83 #define srtp_auth_compute(a, buf, len, res) \
84  (((a)->type)->compute((a)->state, (buf), (len), (a)->out_len, (res)))
85 
86 #define srtp_auth_update(a, buf, len) \
87  (((a)->type)->update((a)->state, (buf), (len)))
88 
89 #define srtp_auth_start(a)(((a)->type)->start((a)->state))
90 
91 #define srtp_auth_dealloc(c) (((c)->type)->dealloc(c))
92 
93 /* functions to get information about a particular auth_t */
94 int srtp_auth_get_key_length(const struct srtp_auth_t *a);
95 
96 int srtp_auth_get_tag_length(const struct srtp_auth_t *a);
97 
98 int srtp_auth_get_prefix_length(const struct srtp_auth_t *a);
99 
100 /*
101  * srtp_auth_test_case_t is a (list of) key/message/tag values that are
102  * known to be correct for a particular cipher. this data can be used
103  * to test an implementation in an on-the-fly self test of the
104  * correctness of the implementation. (see the srtp_auth_type_self_test()
105  * function below)
106  */
107 typedef struct srtp_auth_test_case_t {
108  int key_length_octets; /* octets in key */
109  const uint8_t *key; /* key */
110  int data_length_octets; /* octets in data */
111  const uint8_t *data; /* data */
112  int tag_length_octets; /* octets in tag */
113  const uint8_t *tag; /* tag */
114  const struct srtp_auth_test_case_t *next_test_case; /* pointer to next testcase */
116 
117 /* srtp_auth_type_t */
118 typedef struct srtp_auth_type_t {
119  srtp_auth_alloc_func alloc;
120  srtp_auth_dealloc_func dealloc;
121  srtp_auth_init_func init;
122  srtp_auth_compute_func compute;
123  srtp_auth_update_func update;
124  srtp_auth_start_func start;
125  const char *description;
126  const srtp_auth_test_case_t *test_data;
129 
130 typedef struct srtp_auth_t {
131  const srtp_auth_type_t *type;
132  void *state;
133  int out_len; /* length of output tag in octets */
134  int key_len; /* length of key in octets */
135  int prefix_len; /* length of keystream prefix */
136 } srtp_auth_t;
137 
138 /*
139  * srtp_auth_type_self_test() tests an auth_type against test cases
140  * provided in an array of values of key/message/tag that is known to
141  * be good
142  */
143 srtp_err_status_t srtp_auth_type_self_test(const srtp_auth_type_t *at);
144 
145 /*
146  * srtp_auth_type_test() tests an auth_type against external test cases
147  * provided in an array of values of key/message/tag that is known to
148  * be good
149  */
150 srtp_err_status_t srtp_auth_type_test(const srtp_auth_type_t *at,
151  const srtp_auth_test_case_t *test_data);
152 
153 /*
154  * srtp_replace_auth_type(ct, id)
155  *
156  * replaces srtp's kernel's auth type implementation for the auth_type id
157  * with a new one passed in externally. The new auth type must pass all the
158  * existing auth_type's self tests as well as its own.
159  */
160 srtp_err_status_t srtp_replace_auth_type(const srtp_auth_type_t *ct, srtp_auth_type_id_t id);
161 
162 #ifdef __cplusplus
163 }
164 #endif
165 
166 #endif /* SRTP_AUTH_H */
Definition: auth.h:107
Definition: auth.h:118
uint32_t srtp_auth_type_id_t
An srtp_auth_type_id_t is an identifier for a particular authentication function. ...
Definition: srtp.h:249
srtp_err_status_t
Definition: srtp.h:259
Definition: auth.h:130