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68 lines
2.0 KiB
Go
68 lines
2.0 KiB
Go
/*
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* Copyright (c) 2014, Yawning Angel <yawning at torproject dot org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* * Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* * Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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package obfs4
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import (
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csrand "crypto/rand"
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"fmt"
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"math/big"
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"math/rand"
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)
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var (
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csRandSourceInstance csRandSource
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csRandInstance = rand.New(csRandSourceInstance)
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)
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type csRandSource struct {
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// This does not keep any state as it is backed by crypto/rand.
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}
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func (r csRandSource) Int63() int64 {
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ret, err := csrand.Int(csrand.Reader, big.NewInt(int64((1<<63)-1)))
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if err != nil {
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panic(err)
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}
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return ret.Int64()
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}
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func (r csRandSource) Seed(seed int64) {
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// No-op.
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}
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func randRange(min, max int) int {
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if max < min {
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panic(fmt.Sprintf("randRange: min > max (%d, %d)", min, max))
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}
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r := (max + 1) - min
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ret := csRandInstance.Intn(r)
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return ret + min
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}
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