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/*
* replay-database.h
*
* interface for a replay database for packet security
*
* David A. McGrew
* Cisco Systems, Inc.
*/
/*
*
* Copyright (c) 2001-2006, Cisco Systems, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* Neither the name of the Cisco Systems, Inc. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#ifndef REPLAY_DB_H
#define REPLAY_DB_H
#include "integers.h" /* for uint32_t */
#include "datatypes.h" /* for v128_t */
#include "err.h" /* for srtp_err_status_t */
#ifdef __cplusplus
extern "C" {
#endif
/*
* if the ith least significant bit is one, then the packet index
* window_end-i is in the database
*/
typedef struct {
uint32_t window_start; /* packet index of the first bit in bitmask */
v128_t bitmask;
} srtp_rdb_t;
#define rdb_bits_in_bitmask (8 * sizeof(v128_t))
/*
* srtp_rdb_init
*
* initalizes rdb
*
* returns srtp_err_status_ok on success, srtp_err_status_t_fail otherwise
*/
srtp_err_status_t srtp_rdb_init(srtp_rdb_t *rdb);
/*
* srtp_rdb_check
*
* checks to see if index appears in rdb
*
* returns srtp_err_status_fail if the index already appears in rdb,
* returns srtp_err_status_ok otherwise
*/
srtp_err_status_t srtp_rdb_check(const srtp_rdb_t *rdb, uint32_t rdb_index);
/*
* srtp_rdb_add_index
*
* adds index to srtp_rdb_t (and does *not* check if index appears in db)
*
* returns srtp_err_status_ok on success, srtp_err_status_fail otherwise
*
*/
srtp_err_status_t srtp_rdb_add_index(srtp_rdb_t *rdb, uint32_t rdb_index);
/*
* the functions srtp_rdb_increment() and srtp_rdb_get_value() are for use by
* senders, not receivers - DO NOT use these functions on the same
* srtp_rdb_t upon which srtp_rdb_add_index is used!
*/
/*
* srtp_rdb_increment(db) increments the sequence number in db, if it is
* not too high
*
* return values:
*
* srtp_err_status_ok no problem
* srtp_err_status_key_expired sequence number too high
*
*/
srtp_err_status_t srtp_rdb_increment(srtp_rdb_t *rdb);
/*
* srtp_rdb_get_value(db) returns the current sequence number of db
*/
uint32_t srtp_rdb_get_value(const srtp_rdb_t *rdb);
#ifdef __cplusplus
}
#endif
#endif /* REPLAY_DB_H */
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