diff options
| author | Jason A. Donenfeld <Jason@zx2c4.com> | 2018-05-23 02:32:02 +0200 |
|---|---|---|
| committer | Jason A. Donenfeld <Jason@zx2c4.com> | 2018-05-23 03:58:27 +0200 |
| commit | 5a2228a5c910ada948677f1dd3fcc59f74e5cb20 (patch) | |
| tree | bafb31cbcc18221e2299f8fef21d9c2f4471f706 /replay.go | |
| parent | 0a63188afab1dd49380f916963307f9b2efdcac1 (diff) | |
Move replay into subpackage
Diffstat (limited to 'replay.go')
| -rw-r--r-- | replay.go | 79 |
1 files changed, 0 insertions, 79 deletions
diff --git a/replay.go b/replay.go deleted file mode 100644 index 2d9c6e1..0000000 --- a/replay.go +++ /dev/null @@ -1,79 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 - * - * Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. - * Copyright (C) 2017-2018 Mathias N. Hall-Andersen <mathias@hall-andersen.dk>. - */ - -package main - -/* Copyright (C) 2015-2017 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */ - -/* Implementation of RFC6479 - * https://tools.ietf.org/html/rfc6479 - * - * The implementation is not safe for concurrent use! - */ - -const ( - // See: https://golang.org/src/math/big/arith.go - _Wordm = ^uintptr(0) - _WordLogSize = _Wordm>>8&1 + _Wordm>>16&1 + _Wordm>>32&1 - _WordSize = 1 << _WordLogSize -) - -const ( - CounterRedundantBitsLog = _WordLogSize + 3 - CounterRedundantBits = _WordSize * 8 - CounterBitsTotal = 2048 - CounterWindowSize = uint64(CounterBitsTotal - CounterRedundantBits) -) - -const ( - BacktrackWords = CounterBitsTotal / _WordSize -) - -type ReplayFilter struct { - counter uint64 - backtrack [BacktrackWords]uintptr -} - -func (filter *ReplayFilter) Init() { - filter.counter = 0 - filter.backtrack[0] = 0 -} - -func (filter *ReplayFilter) ValidateCounter(counter uint64) bool { - if counter >= RejectAfterMessages { - return false - } - - indexWord := counter >> CounterRedundantBitsLog - - if counter > filter.counter { - - // move window forward - - current := filter.counter >> CounterRedundantBitsLog - diff := minUint64(indexWord-current, BacktrackWords) - for i := uint64(1); i <= diff; i++ { - filter.backtrack[(current+i)%BacktrackWords] = 0 - } - filter.counter = counter - - } else if filter.counter-counter > CounterWindowSize { - - // behind current window - - return false - } - - indexWord %= BacktrackWords - indexBit := counter & uint64(CounterRedundantBits-1) - - // check and set bit - - oldValue := filter.backtrack[indexWord] - newValue := oldValue | (1 << indexBit) - filter.backtrack[indexWord] = newValue - return oldValue != newValue -} |