304 lines
7.5 KiB
Go
304 lines
7.5 KiB
Go
// Copyright 2017 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.
|
|
|
|
//go:build gc && !purego
|
|
|
|
package sha3
|
|
|
|
// This file contains code for using the 'compute intermediate
|
|
// message digest' (KIMD) and 'compute last message digest' (KLMD)
|
|
// instructions to compute SHA-3 and SHAKE hashes on IBM Z.
|
|
|
|
import (
|
|
"hash"
|
|
|
|
"golang.org/x/sys/cpu"
|
|
)
|
|
|
|
// codes represent 7-bit KIMD/KLMD function codes as defined in
|
|
// the Principles of Operation.
|
|
type code uint64
|
|
|
|
const (
|
|
// function codes for KIMD/KLMD
|
|
sha3_224 code = 32
|
|
sha3_256 = 33
|
|
sha3_384 = 34
|
|
sha3_512 = 35
|
|
shake_128 = 36
|
|
shake_256 = 37
|
|
nopad = 0x100
|
|
)
|
|
|
|
// kimd is a wrapper for the 'compute intermediate message digest' instruction.
|
|
// src must be a multiple of the rate for the given function code.
|
|
//
|
|
//go:noescape
|
|
func kimd(function code, chain *[200]byte, src []byte)
|
|
|
|
// klmd is a wrapper for the 'compute last message digest' instruction.
|
|
// src padding is handled by the instruction.
|
|
//
|
|
//go:noescape
|
|
func klmd(function code, chain *[200]byte, dst, src []byte)
|
|
|
|
type asmState struct {
|
|
a [200]byte // 1600 bit state
|
|
buf []byte // care must be taken to ensure cap(buf) is a multiple of rate
|
|
rate int // equivalent to block size
|
|
storage [3072]byte // underlying storage for buf
|
|
outputLen int // output length for full security
|
|
function code // KIMD/KLMD function code
|
|
state spongeDirection // whether the sponge is absorbing or squeezing
|
|
}
|
|
|
|
func newAsmState(function code) *asmState {
|
|
var s asmState
|
|
s.function = function
|
|
switch function {
|
|
case sha3_224:
|
|
s.rate = 144
|
|
s.outputLen = 28
|
|
case sha3_256:
|
|
s.rate = 136
|
|
s.outputLen = 32
|
|
case sha3_384:
|
|
s.rate = 104
|
|
s.outputLen = 48
|
|
case sha3_512:
|
|
s.rate = 72
|
|
s.outputLen = 64
|
|
case shake_128:
|
|
s.rate = 168
|
|
s.outputLen = 32
|
|
case shake_256:
|
|
s.rate = 136
|
|
s.outputLen = 64
|
|
default:
|
|
panic("sha3: unrecognized function code")
|
|
}
|
|
|
|
// limit s.buf size to a multiple of s.rate
|
|
s.resetBuf()
|
|
return &s
|
|
}
|
|
|
|
func (s *asmState) clone() *asmState {
|
|
c := *s
|
|
c.buf = c.storage[:len(s.buf):cap(s.buf)]
|
|
return &c
|
|
}
|
|
|
|
// copyIntoBuf copies b into buf. It will panic if there is not enough space to
|
|
// store all of b.
|
|
func (s *asmState) copyIntoBuf(b []byte) {
|
|
bufLen := len(s.buf)
|
|
s.buf = s.buf[:len(s.buf)+len(b)]
|
|
copy(s.buf[bufLen:], b)
|
|
}
|
|
|
|
// resetBuf points buf at storage, sets the length to 0 and sets cap to be a
|
|
// multiple of the rate.
|
|
func (s *asmState) resetBuf() {
|
|
max := (cap(s.storage) / s.rate) * s.rate
|
|
s.buf = s.storage[:0:max]
|
|
}
|
|
|
|
// Write (via the embedded io.Writer interface) adds more data to the running hash.
|
|
// It never returns an error.
|
|
func (s *asmState) Write(b []byte) (int, error) {
|
|
if s.state != spongeAbsorbing {
|
|
panic("sha3: Write after Read")
|
|
}
|
|
length := len(b)
|
|
for len(b) > 0 {
|
|
if len(s.buf) == 0 && len(b) >= cap(s.buf) {
|
|
// Hash the data directly and push any remaining bytes
|
|
// into the buffer.
|
|
remainder := len(b) % s.rate
|
|
kimd(s.function, &s.a, b[:len(b)-remainder])
|
|
if remainder != 0 {
|
|
s.copyIntoBuf(b[len(b)-remainder:])
|
|
}
|
|
return length, nil
|
|
}
|
|
|
|
if len(s.buf) == cap(s.buf) {
|
|
// flush the buffer
|
|
kimd(s.function, &s.a, s.buf)
|
|
s.buf = s.buf[:0]
|
|
}
|
|
|
|
// copy as much as we can into the buffer
|
|
n := len(b)
|
|
if len(b) > cap(s.buf)-len(s.buf) {
|
|
n = cap(s.buf) - len(s.buf)
|
|
}
|
|
s.copyIntoBuf(b[:n])
|
|
b = b[n:]
|
|
}
|
|
return length, nil
|
|
}
|
|
|
|
// Read squeezes an arbitrary number of bytes from the sponge.
|
|
func (s *asmState) Read(out []byte) (n int, err error) {
|
|
// The 'compute last message digest' instruction only stores the digest
|
|
// at the first operand (dst) for SHAKE functions.
|
|
if s.function != shake_128 && s.function != shake_256 {
|
|
panic("sha3: can only call Read for SHAKE functions")
|
|
}
|
|
|
|
n = len(out)
|
|
|
|
// need to pad if we were absorbing
|
|
if s.state == spongeAbsorbing {
|
|
s.state = spongeSqueezing
|
|
|
|
// write hash directly into out if possible
|
|
if len(out)%s.rate == 0 {
|
|
klmd(s.function, &s.a, out, s.buf) // len(out) may be 0
|
|
s.buf = s.buf[:0]
|
|
return
|
|
}
|
|
|
|
// write hash into buffer
|
|
max := cap(s.buf)
|
|
if max > len(out) {
|
|
max = (len(out)/s.rate)*s.rate + s.rate
|
|
}
|
|
klmd(s.function, &s.a, s.buf[:max], s.buf)
|
|
s.buf = s.buf[:max]
|
|
}
|
|
|
|
for len(out) > 0 {
|
|
// flush the buffer
|
|
if len(s.buf) != 0 {
|
|
c := copy(out, s.buf)
|
|
out = out[c:]
|
|
s.buf = s.buf[c:]
|
|
continue
|
|
}
|
|
|
|
// write hash directly into out if possible
|
|
if len(out)%s.rate == 0 {
|
|
klmd(s.function|nopad, &s.a, out, nil)
|
|
return
|
|
}
|
|
|
|
// write hash into buffer
|
|
s.resetBuf()
|
|
if cap(s.buf) > len(out) {
|
|
s.buf = s.buf[:(len(out)/s.rate)*s.rate+s.rate]
|
|
}
|
|
klmd(s.function|nopad, &s.a, s.buf, nil)
|
|
}
|
|
return
|
|
}
|
|
|
|
// Sum appends the current hash to b and returns the resulting slice.
|
|
// It does not change the underlying hash state.
|
|
func (s *asmState) Sum(b []byte) []byte {
|
|
if s.state != spongeAbsorbing {
|
|
panic("sha3: Sum after Read")
|
|
}
|
|
|
|
// Copy the state to preserve the original.
|
|
a := s.a
|
|
|
|
// Hash the buffer. Note that we don't clear it because we
|
|
// aren't updating the state.
|
|
switch s.function {
|
|
case sha3_224, sha3_256, sha3_384, sha3_512:
|
|
klmd(s.function, &a, nil, s.buf)
|
|
return append(b, a[:s.outputLen]...)
|
|
case shake_128, shake_256:
|
|
d := make([]byte, s.outputLen, 64)
|
|
klmd(s.function, &a, d, s.buf)
|
|
return append(b, d[:s.outputLen]...)
|
|
default:
|
|
panic("sha3: unknown function")
|
|
}
|
|
}
|
|
|
|
// Reset resets the Hash to its initial state.
|
|
func (s *asmState) Reset() {
|
|
for i := range s.a {
|
|
s.a[i] = 0
|
|
}
|
|
s.resetBuf()
|
|
s.state = spongeAbsorbing
|
|
}
|
|
|
|
// Size returns the number of bytes Sum will return.
|
|
func (s *asmState) Size() int {
|
|
return s.outputLen
|
|
}
|
|
|
|
// BlockSize returns the hash's underlying block size.
|
|
// The Write method must be able to accept any amount
|
|
// of data, but it may operate more efficiently if all writes
|
|
// are a multiple of the block size.
|
|
func (s *asmState) BlockSize() int {
|
|
return s.rate
|
|
}
|
|
|
|
// Clone returns a copy of the ShakeHash in its current state.
|
|
func (s *asmState) Clone() ShakeHash {
|
|
return s.clone()
|
|
}
|
|
|
|
// new224 returns an assembly implementation of SHA3-224 if available,
|
|
// otherwise it returns a generic implementation.
|
|
func new224() hash.Hash {
|
|
if cpu.S390X.HasSHA3 {
|
|
return newAsmState(sha3_224)
|
|
}
|
|
return new224Generic()
|
|
}
|
|
|
|
// new256 returns an assembly implementation of SHA3-256 if available,
|
|
// otherwise it returns a generic implementation.
|
|
func new256() hash.Hash {
|
|
if cpu.S390X.HasSHA3 {
|
|
return newAsmState(sha3_256)
|
|
}
|
|
return new256Generic()
|
|
}
|
|
|
|
// new384 returns an assembly implementation of SHA3-384 if available,
|
|
// otherwise it returns a generic implementation.
|
|
func new384() hash.Hash {
|
|
if cpu.S390X.HasSHA3 {
|
|
return newAsmState(sha3_384)
|
|
}
|
|
return new384Generic()
|
|
}
|
|
|
|
// new512 returns an assembly implementation of SHA3-512 if available,
|
|
// otherwise it returns a generic implementation.
|
|
func new512() hash.Hash {
|
|
if cpu.S390X.HasSHA3 {
|
|
return newAsmState(sha3_512)
|
|
}
|
|
return new512Generic()
|
|
}
|
|
|
|
// newShake128 returns an assembly implementation of SHAKE-128 if available,
|
|
// otherwise it returns a generic implementation.
|
|
func newShake128() ShakeHash {
|
|
if cpu.S390X.HasSHA3 {
|
|
return newAsmState(shake_128)
|
|
}
|
|
return newShake128Generic()
|
|
}
|
|
|
|
// newShake256 returns an assembly implementation of SHAKE-256 if available,
|
|
// otherwise it returns a generic implementation.
|
|
func newShake256() ShakeHash {
|
|
if cpu.S390X.HasSHA3 {
|
|
return newAsmState(shake_256)
|
|
}
|
|
return newShake256Generic()
|
|
}
|