| /* |
| * replay-database.h |
| * |
| * interface for a replay database for packet security |
| * |
| * David A. McGrew |
| * Cisco Systems, Inc. |
| */ |
| |
| |
| #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 */ |
| |
| /* |
| * 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); |
| |
| |
| #endif /* REPLAY_DB_H */ |