80 lines
2.3 KiB
Go
80 lines
2.3 KiB
Go
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// Copyright 2014 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package sha3
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// This file defines the ShakeHash interface, and provides
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// functions for creating SHAKE and cSHAKE instances, as well as utility
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// functions for hashing bytes to arbitrary-length output.
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//
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//
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// SHAKE implementation is based on FIPS PUB 202 [1]
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// cSHAKE implementations is based on NIST SP 800-185 [2]
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//
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// [1] https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf
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// [2] https://doi.org/10.6028/NIST.SP.800-185
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import (
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"io"
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)
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// ShakeHash defines the interface to hash functions that
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// support arbitrary-length output.
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type ShakeHash interface {
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// Write absorbs more data into the hash's state. It panics if input is
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// written to it after output has been read from it.
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io.Writer
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// Read reads more output from the hash; reading affects the hash's
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// state. (ShakeHash.Read is thus very different from Hash.Sum)
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// It never returns an error.
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io.Reader
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// Clone returns a copy of the ShakeHash in its current state.
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Clone() ShakeHash
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// Reset resets the ShakeHash to its initial state.
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Reset()
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}
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// Consts for configuring initial SHA-3 state
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const (
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dsbyteShake = 0x1f
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rate128 = 168
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rate256 = 136
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)
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// Clone returns copy of SHAKE context within its current state.
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func (d *State) Clone() ShakeHash {
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return d.clone()
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}
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// NewShake128 creates a new SHAKE128 variable-output-length ShakeHash.
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// Its generic security strength is 128 bits against all attacks if at
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// least 32 bytes of its output are used.
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func NewShake128() State {
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return State{rate: rate128, dsbyte: dsbyteShake}
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}
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// NewShake256 creates a new SHAKE256 variable-output-length ShakeHash.
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// Its generic security strength is 256 bits against all attacks if
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// at least 64 bytes of its output are used.
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func NewShake256() State {
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return State{rate: rate256, dsbyte: dsbyteShake}
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}
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// ShakeSum128 writes an arbitrary-length digest of data into hash.
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func ShakeSum128(hash, data []byte) {
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h := NewShake128()
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_, _ = h.Write(data)
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_, _ = h.Read(hash)
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}
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// ShakeSum256 writes an arbitrary-length digest of data into hash.
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func ShakeSum256(hash, data []byte) {
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h := NewShake256()
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_, _ = h.Write(data)
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_, _ = h.Read(hash)
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}
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