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 #ifndef REC_ANTI_REPLAY_H 17 #define REC_ANTI_REPLAY_H 18 19 #include <stdint.h> 20 #include <stdbool.h> 21 22 #ifdef __cplusplus 23 extern "C" { 24 #endif 25 26 /** 27 * Anti-replay check function: 28 * Use uint64_t variable to store flag bit，When receive a message, set the flag of corresponding sequence number to 1 29 * The least significant bit of the variable stores the maximum sequence number of the sliding window top, 30 * when the top updates, shift the sliding window to the left 31 * If a duplicate message or a message whose sequence number is smaller than the minimum sliding window value 32 * is received, discard it 33 * 34 * window: 64 bits Range: [top-63, top) 35 * 1. Initial state： 36 * top - 63 top 37 * | - - - - - - | 38 * 2. hen the top + 2 message is received： 39 * top - 61 top + 2 40 * | - - - - - - | 41 */ 42 typedef struct { 43 uint64_t top; /* Stores the current maximum sequence number */ 44 uint64_t window; /* Sliding window for storing flag bits */ 45 } RecSlidWindow; 46 47 /** 48 * @brief Reset of the anti-replay module 49 * The invoker must ensure that the input parameter is not empty 50 * 51 * @param w [IN] Sliding window 52 */ 53 void RecAntiReplayReset(RecSlidWindow *w); 54 55 /** 56 * @brief Anti-Replay Check 57 * The invoker must ensure that the input parameter is not empty 58 * 59 * @param w [IN] Sliding window 60 * @param seq [IN] Sequence number to be checked 61 * 62 * @retval true The sequence number is duplicate 63 * @retval false The sequence number is not duplicate 64 */ 65 bool RecAntiReplayCheck(const RecSlidWindow *w, uint64_t seq); 66 67 /** 68 * @brief Update the window 69 * This function can be invoked only after the anti-replay check is passed 70 * Ensure that the input parameter is not empty by the invoker 71 * 72 * @param w [IN] Sliding window. The input parameter correctness is ensured externally 73 * @param seq [IN] Sequence number of the window to be updated 74 */ 75 void RecAntiReplayUpdate(RecSlidWindow *w, uint64_t seq); 76 77 #ifdef __cplusplus 78 } 79 #endif 80 81 #endif /* REC_ANTI_REPLAY_H */ 82