Files
tss-lib/common/hash.go
Luke Plaster 3050a2bab2 Add copyright (#58)
* add copyright comments

* add .idea files for copyright
2019-09-29 15:09:37 +08:00

101 lines
3.2 KiB
Go

// Copyright © 2019 Binance
//
// This file is part of Binance. The full Binance copyright notice, including
// terms governing use, modification, and redistribution, is contained in the
// file LICENSE at the root of the source code distribution tree.
package common
import (
"crypto"
_ "crypto/sha512"
"encoding/binary"
"math/big"
)
const (
hashInputDelimiter = byte('$')
)
// SHA-512/256 is protected against length extension attacks and is more performant than SHA-256 on 64-bit architectures.
// https://en.wikipedia.org/wiki/Template:Comparison_of_SHA_functions
func SHA512_256(in ...[]byte) []byte {
var data []byte
state := crypto.SHA512_256.New()
inLen := len(in)
if inLen == 0 {
return nil
}
bzSize := 0
// prevent hash collisions with this prefix containing the block count
inLenBz := make([]byte, 64/8)
// converting between int and uint64 doesn't change the sign bit, but it may be interpreted as a larger value.
// this prefix is never read/interpreted, so that doesn't matter.
binary.LittleEndian.PutUint64(inLenBz, uint64(inLen))
for _, bz := range in {
bzSize += len(bz)
}
data = make([]byte, 0, len(inLenBz)+bzSize+inLen)
data = append(data, inLenBz...)
for _, bz := range in {
data = append(data, bz...)
data = append(data, hashInputDelimiter) // safety delimiter
}
// n < len(data) or an error will never happen.
// see: https://golang.org/pkg/hash/#Hash and https://github.com/golang/go/wiki/Hashing#the-hashhash-interface
if _, err := state.Write(data); err != nil {
Logger.Errorf("SHA512_256 Write() failed: %v", err)
return nil
}
return state.Sum(nil)
}
func SHA512_256i(in ...*big.Int) *big.Int {
var data []byte
state := crypto.SHA512_256.New()
inLen := len(in)
if inLen == 0 {
return nil
}
bzSize := 0
// prevent hash collisions with this prefix containing the block count
inLenBz := make([]byte, 64/8)
// converting between int and uint64 doesn't change the sign bit, but it may be interpreted as a larger value.
// this prefix is never read/interpreted, so that doesn't matter.
binary.LittleEndian.PutUint64(inLenBz, uint64(inLen))
ptrs := make([][]byte, inLen)
for i, n := range in {
ptrs[i] = n.Bytes()
bzSize += len(ptrs[i])
}
data = make([]byte, 0, len(inLenBz)+bzSize+inLen)
data = append(data, inLenBz...)
for i := range in {
data = append(data, ptrs[i]...)
data = append(data, hashInputDelimiter) // safety delimiter
}
// n < len(data) or an error will never happen.
// see: https://golang.org/pkg/hash/#Hash and https://github.com/golang/go/wiki/Hashing#the-hashhash-interface
if _, err := state.Write(data); err != nil {
Logger.Errorf("SHA512_256i Write() failed: %v", err)
return nil
}
return new(big.Int).SetBytes(state.Sum(nil))
}
func SHA512_256iOne(in *big.Int) *big.Int {
var data []byte
state := crypto.SHA512_256.New()
if in == nil {
return nil
}
data = in.Bytes()
// n < len(data) or an error will never happen.
// see: https://golang.org/pkg/hash/#Hash and https://github.com/golang/go/wiki/Hashing#the-hashhash-interface
if _, err := state.Write(data); err != nil {
Logger.Errorf("SHA512_256iOne Write() failed: %v", err)
return nil
}
return new(big.Int).SetBytes(state.Sum(nil))
}