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/*
* Copyright (c) 2014, Yawning Angel <yawning at torproject dot org>
* 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.
*
* 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 HOLDER 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.
*/
package obfs4
import (
csrand "crypto/rand"
"fmt"
"math/big"
"math/rand"
)
var (
csRandSourceInstance csRandSource
csRandInstance = rand.New(csRandSourceInstance)
)
type csRandSource struct {
// This does not keep any state as it is backed by crypto/rand.
}
func (r csRandSource) Int63() int64 {
ret, err := csrand.Int(csrand.Reader, big.NewInt(int64((1<<63)-1)))
if err != nil {
panic(err)
}
return ret.Int64()
}
func (r csRandSource) Seed(seed int64) {
// No-op.
}
func randRange(min, max int) int {
if max < min {
panic(fmt.Sprintf("randRange: min > max (%d, %d)", min, max))
}
r := (max + 1) - min
ret := csRandInstance.Intn(r)
return ret + min
}
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