plugeth/crypto/randentropy/rand_entropy.go

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// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
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//
// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package randentropy
import (
crand "crypto/rand"
"io"
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"github.com/ethereum/go-ethereum/crypto/sha3"
)
var Reader io.Reader = &randEntropy{}
type randEntropy struct {
}
func (*randEntropy) Read(bytes []byte) (n int, err error) {
readBytes := GetEntropyCSPRNG(len(bytes))
copy(bytes, readBytes)
return len(bytes), nil
}
// TODO: copied from crypto.go , move to sha3 package?
func Sha3(data []byte) []byte {
d := sha3.NewKeccak256()
d.Write(data)
return d.Sum(nil)
}
func GetEntropyCSPRNG(n int) []byte {
mainBuff := make([]byte, n)
_, err := io.ReadFull(crand.Reader, mainBuff)
if err != nil {
panic("reading from crypto/rand failed: " + err.Error())
}
return mainBuff
}