1 /* 2 * replay-database.h 3 * 4 * interface for a replay database for packet security 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 REPLAY_DB_H 47 #define REPLAY_DB_H 48 49 #include "integers.h" /* for uint32_t */ 50 #include "datatypes.h" /* for v128_t */ 51 #include "err.h" /* for srtp_err_status_t */ 52 53 #ifdef __cplusplus 54 extern "C" { 55 #endif 56 57 /* 58 * if the ith least significant bit is one, then the packet index 59 * window_end-i is in the database 60 */ 61 62 typedef struct { 63 uint32_t window_start; /* packet index of the first bit in bitmask */ 64 v128_t bitmask; 65 } srtp_rdb_t; 66 67 #define rdb_bits_in_bitmask (8 * sizeof(v128_t)) 68 69 /* 70 * srtp_rdb_init 71 * 72 * initalizes rdb 73 * 74 * returns srtp_err_status_ok on success, srtp_err_status_t_fail otherwise 75 */ 76 srtp_err_status_t srtp_rdb_init(srtp_rdb_t *rdb); 77 78 /* 79 * srtp_rdb_check 80 * 81 * checks to see if index appears in rdb 82 * 83 * returns srtp_err_status_fail if the index already appears in rdb, 84 * returns srtp_err_status_ok otherwise 85 */ 86 srtp_err_status_t srtp_rdb_check(const srtp_rdb_t *rdb, uint32_t rdb_index); 87 88 /* 89 * srtp_rdb_add_index 90 * 91 * adds index to srtp_rdb_t (and does *not* check if index appears in db) 92 * 93 * returns srtp_err_status_ok on success, srtp_err_status_fail otherwise 94 * 95 */ 96 srtp_err_status_t srtp_rdb_add_index(srtp_rdb_t *rdb, uint32_t rdb_index); 97 98 /* 99 * the functions srtp_rdb_increment() and srtp_rdb_get_value() are for use by 100 * senders, not receivers - DO NOT use these functions on the same 101 * srtp_rdb_t upon which srtp_rdb_add_index is used! 102 */ 103 104 /* 105 * srtp_rdb_increment(db) increments the sequence number in db, if it is 106 * not too high 107 * 108 * return values: 109 * 110 * srtp_err_status_ok no problem 111 * srtp_err_status_key_expired sequence number too high 112 * 113 */ 114 srtp_err_status_t srtp_rdb_increment(srtp_rdb_t *rdb); 115 116 /* 117 * srtp_rdb_get_value(db) returns the current sequence number of db 118 */ 119 uint32_t srtp_rdb_get_value(const srtp_rdb_t *rdb); 120 121 #ifdef __cplusplus 122 } 123 #endif 124 125 #endif /* REPLAY_DB_H */ 126