1 /*
2 * This file is part of the openHiTLS project.
3 *
4 * openHiTLS is licensed under the Mulan PSL v2.
5 * You can use this software according to the terms and conditions of the Mulan PSL v2.
6 * You may obtain a copy of Mulan PSL v2 at:
7 *
8 * http://license.coscl.org.cn/MulanPSL2
9 *
10 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
11 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
12 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
13 * See the Mulan PSL v2 for more details.
14 */
15
16 #include "hitls_build.h"
17 #if defined(HITLS_TLS_PROTO_DTLS12) && defined(HITLS_BSL_UIO_UDP)
18 #include "rec_anti_replay.h"
19
20 #define REC_SLID_WINDOW_SIZE 64
21
RecAntiReplayReset(RecSlidWindow * w)22 void RecAntiReplayReset(RecSlidWindow *w)
23 {
24 w->top = 0;
25 w->window = 0;
26 return;
27 }
28
RecAntiReplayCheck(const RecSlidWindow * w,uint64_t seq)29 bool RecAntiReplayCheck(const RecSlidWindow *w, uint64_t seq)
30 {
31 if (seq > w->top) {
32 return false;
33 }
34
35 uint64_t bit = w->top - seq;
36 if (bit >= REC_SLID_WINDOW_SIZE) {
37 /* The sequence number must be smaller than or equal to the minimum value of the sliding window */
38 return true;
39 }
40 /* return true: The sequence number is equal to a certain value in the sliding window */
41 return (w->window & ((uint64_t)1 << bit)) != 0;
42 }
43
RecAntiReplayUpdate(RecSlidWindow * w,uint64_t seq)44 void RecAntiReplayUpdate(RecSlidWindow *w, uint64_t seq)
45 {
46 /* If the sequence number is too small, the flag bit is not updated */
47 if ((seq + REC_SLID_WINDOW_SIZE) <= w->top) {
48 return;
49 }
50
51 /* If the sequence number is less than or equal to top, update the flag */
52 if (seq <= w->top) {
53 uint64_t bit = w->top - seq;
54 w->window |= (uint64_t)1 << bit;
55 return;
56 }
57
58 /* If the sequence number is greater than top, update the maximum sliding window size */
59 uint64_t bit = seq - w->top;
60 w->top = seq;
61 if (bit >= REC_SLID_WINDOW_SIZE) {
62 /* If the number exceeds the current number too much, all previous flags are cleared and the maximum value is
63 * updated */
64 w->window = 1;
65 } else {
66 w->window <<= bit;
67 w->window |= 1;
68 }
69 return;
70 }
71 #endif /* HITLS_TLS_PROTO_DTLS12 && HITLS_BSL_UIO_UDP */