/src/pjsip/third_party/srtp/crypto/kernel/key.c
Line | Count | Source |
1 | | /* |
2 | | * key.c |
3 | | * |
4 | | * key usage limits enforcement |
5 | | * |
6 | | * David A. Mcgrew |
7 | | * Cisco Systems, Inc. |
8 | | */ |
9 | | /* |
10 | | * |
11 | | * Copyright (c) 2001-2017 Cisco Systems, Inc. |
12 | | * All rights reserved. |
13 | | * |
14 | | * Redistribution and use in source and binary forms, with or without |
15 | | * modification, are permitted provided that the following conditions |
16 | | * are met: |
17 | | * |
18 | | * Redistributions of source code must retain the above copyright |
19 | | * notice, this list of conditions and the following disclaimer. |
20 | | * |
21 | | * Redistributions in binary form must reproduce the above |
22 | | * copyright notice, this list of conditions and the following |
23 | | * disclaimer in the documentation and/or other materials provided |
24 | | * with the distribution. |
25 | | * |
26 | | * Neither the name of the Cisco Systems, Inc. nor the names of its |
27 | | * contributors may be used to endorse or promote products derived |
28 | | * from this software without specific prior written permission. |
29 | | * |
30 | | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
31 | | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
32 | | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
33 | | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
34 | | * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, |
35 | | * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
36 | | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
37 | | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
38 | | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
39 | | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
40 | | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
41 | | * OF THE POSSIBILITY OF SUCH DAMAGE. |
42 | | * |
43 | | */ |
44 | | |
45 | | #ifdef HAVE_CONFIG_H |
46 | | #include <config.h> |
47 | | #endif |
48 | | |
49 | | #include "key.h" |
50 | | |
51 | 884 | #define soft_limit 0x10000 |
52 | | |
53 | | srtp_err_status_t srtp_key_limit_set(srtp_key_limit_t key, |
54 | | const srtp_xtd_seq_num_t s) |
55 | 878 | { |
56 | | #ifdef NO_64BIT_MATH |
57 | | if (high32(s) == 0 && low32(s) < soft_limit) { |
58 | | return srtp_err_status_bad_param; |
59 | | } |
60 | | #else |
61 | 878 | if (s < soft_limit) { |
62 | 0 | return srtp_err_status_bad_param; |
63 | 0 | } |
64 | 878 | #endif |
65 | 878 | key->num_left = s; |
66 | 878 | key->state = srtp_key_state_normal; |
67 | 878 | return srtp_err_status_ok; |
68 | 878 | } |
69 | | |
70 | | srtp_err_status_t srtp_key_limit_clone(srtp_key_limit_t original, |
71 | | srtp_key_limit_t *new_key) |
72 | 6 | { |
73 | 6 | if (original == NULL) { |
74 | 0 | return srtp_err_status_bad_param; |
75 | 0 | } |
76 | 6 | *new_key = original; |
77 | 6 | return srtp_err_status_ok; |
78 | 6 | } |
79 | | |
80 | | srtp_key_event_t srtp_key_limit_update(srtp_key_limit_t key) |
81 | 6 | { |
82 | | #ifdef NO_64BIT_MATH |
83 | | if (low32(key->num_left) == 0) { |
84 | | // carry |
85 | | key->num_left = |
86 | | make64(high32(key->num_left) - 1, low32(key->num_left) - 1); |
87 | | } else { |
88 | | // no carry |
89 | | key->num_left = make64(high32(key->num_left), low32(key->num_left) - 1); |
90 | | } |
91 | | if (high32(key->num_left) != 0 || low32(key->num_left) >= soft_limit) { |
92 | | return srtp_key_event_normal; /* we're above the soft limit */ |
93 | | } |
94 | | #else |
95 | 6 | key->num_left--; |
96 | 6 | if (key->num_left >= soft_limit) { |
97 | 6 | return srtp_key_event_normal; /* we're above the soft limit */ |
98 | 6 | } |
99 | 0 | #endif |
100 | 0 | if (key->state == srtp_key_state_normal) { |
101 | | /* we just passed the soft limit, so change the state */ |
102 | 0 | key->state = srtp_key_state_past_soft_limit; |
103 | 0 | } |
104 | | #ifdef NO_64BIT_MATH |
105 | | if (low32(key->num_left) == 0 && high32(key->num_left == 0)) |
106 | | #else |
107 | 0 | if (key->num_left < 1) |
108 | 0 | #endif |
109 | 0 | { /* we just hit the hard limit */ |
110 | 0 | key->state = srtp_key_state_expired; |
111 | 0 | return srtp_key_event_hard_limit; |
112 | 0 | } |
113 | 0 | return srtp_key_event_soft_limit; |
114 | 0 | } |