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-rw-r--r--vendor/golang.org/x/crypto/sha3/shake.go193
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diff --git a/vendor/golang.org/x/crypto/sha3/shake.go b/vendor/golang.org/x/crypto/sha3/shake.go
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--- a/vendor/golang.org/x/crypto/sha3/shake.go
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-// Copyright 2014 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package sha3
-
-// This file defines the ShakeHash interface, and provides
-// functions for creating SHAKE and cSHAKE instances, as well as utility
-// functions for hashing bytes to arbitrary-length output.
-//
-//
-// SHAKE implementation is based on FIPS PUB 202 [1]
-// cSHAKE implementations is based on NIST SP 800-185 [2]
-//
-// [1] https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf
-// [2] https://doi.org/10.6028/NIST.SP.800-185
-
-import (
- "bytes"
- "encoding/binary"
- "errors"
- "hash"
- "io"
- "math/bits"
-)
-
-// ShakeHash defines the interface to hash functions that support
-// arbitrary-length output. When used as a plain [hash.Hash], it
-// produces minimum-length outputs that provide full-strength generic
-// security.
-type ShakeHash interface {
- hash.Hash
-
- // Read reads more output from the hash; reading affects the hash's
- // state. (ShakeHash.Read is thus very different from Hash.Sum)
- // It never returns an error, but subsequent calls to Write or Sum
- // will panic.
- io.Reader
-
- // Clone returns a copy of the ShakeHash in its current state.
- Clone() ShakeHash
-}
-
-// cSHAKE specific context
-type cshakeState struct {
- *state // SHA-3 state context and Read/Write operations
-
- // initBlock is the cSHAKE specific initialization set of bytes. It is initialized
- // by newCShake function and stores concatenation of N followed by S, encoded
- // by the method specified in 3.3 of [1].
- // It is stored here in order for Reset() to be able to put context into
- // initial state.
- initBlock []byte
-}
-
-func bytepad(data []byte, rate int) []byte {
- out := make([]byte, 0, 9+len(data)+rate-1)
- out = append(out, leftEncode(uint64(rate))...)
- out = append(out, data...)
- if padlen := rate - len(out)%rate; padlen < rate {
- out = append(out, make([]byte, padlen)...)
- }
- return out
-}
-
-func leftEncode(x uint64) []byte {
- // Let n be the smallest positive integer for which 2^(8n) > x.
- n := (bits.Len64(x) + 7) / 8
- if n == 0 {
- n = 1
- }
- // Return n || x with n as a byte and x an n bytes in big-endian order.
- b := make([]byte, 9)
- binary.BigEndian.PutUint64(b[1:], x)
- b = b[9-n-1:]
- b[0] = byte(n)
- return b
-}
-
-func newCShake(N, S []byte, rate, outputLen int, dsbyte byte) ShakeHash {
- c := cshakeState{state: &state{rate: rate, outputLen: outputLen, dsbyte: dsbyte}}
- c.initBlock = make([]byte, 0, 9+len(N)+9+len(S)) // leftEncode returns max 9 bytes
- c.initBlock = append(c.initBlock, leftEncode(uint64(len(N))*8)...)
- c.initBlock = append(c.initBlock, N...)
- c.initBlock = append(c.initBlock, leftEncode(uint64(len(S))*8)...)
- c.initBlock = append(c.initBlock, S...)
- c.Write(bytepad(c.initBlock, c.rate))
- return &c
-}
-
-// Reset resets the hash to initial state.
-func (c *cshakeState) Reset() {
- c.state.Reset()
- c.Write(bytepad(c.initBlock, c.rate))
-}
-
-// Clone returns copy of a cSHAKE context within its current state.
-func (c *cshakeState) Clone() ShakeHash {
- b := make([]byte, len(c.initBlock))
- copy(b, c.initBlock)
- return &cshakeState{state: c.clone(), initBlock: b}
-}
-
-// Clone returns copy of SHAKE context within its current state.
-func (c *state) Clone() ShakeHash {
- return c.clone()
-}
-
-func (c *cshakeState) MarshalBinary() ([]byte, error) {
- return c.AppendBinary(make([]byte, 0, marshaledSize+len(c.initBlock)))
-}
-
-func (c *cshakeState) AppendBinary(b []byte) ([]byte, error) {
- b, err := c.state.AppendBinary(b)
- if err != nil {
- return nil, err
- }
- b = append(b, c.initBlock...)
- return b, nil
-}
-
-func (c *cshakeState) UnmarshalBinary(b []byte) error {
- if len(b) <= marshaledSize {
- return errors.New("sha3: invalid hash state")
- }
- if err := c.state.UnmarshalBinary(b[:marshaledSize]); err != nil {
- return err
- }
- c.initBlock = bytes.Clone(b[marshaledSize:])
- return nil
-}
-
-// NewShake128 creates a new SHAKE128 variable-output-length ShakeHash.
-// Its generic security strength is 128 bits against all attacks if at
-// least 32 bytes of its output are used.
-func NewShake128() ShakeHash {
- return newShake128()
-}
-
-// NewShake256 creates a new SHAKE256 variable-output-length ShakeHash.
-// Its generic security strength is 256 bits against all attacks if
-// at least 64 bytes of its output are used.
-func NewShake256() ShakeHash {
- return newShake256()
-}
-
-func newShake128Generic() *state {
- return &state{rate: rateK256, outputLen: 32, dsbyte: dsbyteShake}
-}
-
-func newShake256Generic() *state {
- return &state{rate: rateK512, outputLen: 64, dsbyte: dsbyteShake}
-}
-
-// NewCShake128 creates a new instance of cSHAKE128 variable-output-length ShakeHash,
-// a customizable variant of SHAKE128.
-// N is used to define functions based on cSHAKE, it can be empty when plain cSHAKE is
-// desired. S is a customization byte string used for domain separation - two cSHAKE
-// computations on same input with different S yield unrelated outputs.
-// When N and S are both empty, this is equivalent to NewShake128.
-func NewCShake128(N, S []byte) ShakeHash {
- if len(N) == 0 && len(S) == 0 {
- return NewShake128()
- }
- return newCShake(N, S, rateK256, 32, dsbyteCShake)
-}
-
-// NewCShake256 creates a new instance of cSHAKE256 variable-output-length ShakeHash,
-// a customizable variant of SHAKE256.
-// N is used to define functions based on cSHAKE, it can be empty when plain cSHAKE is
-// desired. S is a customization byte string used for domain separation - two cSHAKE
-// computations on same input with different S yield unrelated outputs.
-// When N and S are both empty, this is equivalent to NewShake256.
-func NewCShake256(N, S []byte) ShakeHash {
- if len(N) == 0 && len(S) == 0 {
- return NewShake256()
- }
- return newCShake(N, S, rateK512, 64, dsbyteCShake)
-}
-
-// ShakeSum128 writes an arbitrary-length digest of data into hash.
-func ShakeSum128(hash, data []byte) {
- h := NewShake128()
- h.Write(data)
- h.Read(hash)
-}
-
-// ShakeSum256 writes an arbitrary-length digest of data into hash.
-func ShakeSum256(hash, data []byte) {
- h := NewShake256()
- h.Write(data)
- h.Read(hash)
-}