// 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
// Tests include all the ShortMsgKATs provided by the Keccak team at
// https://github.com/gvanas/KeccakCodePackage
//
// They only include the zero-bit case of the bitwise testvectors
// published by NIST in the draft of FIPS-202.
import (
"bytes"
"compress/flate"
"encoding/hex"
"encoding/json"
"hash"
"os"
"strings"
"testing"
)
const (
testString = "brekeccakkeccak koax koax"
katFilename = "testdata/keccakKats.json.deflate"
)
// Internal-use instances of SHAKE used to test against KATs.
func newHashShake128() hash.Hash {
return &state{rate: 168, dsbyte: 0x1f, outputLen: 512}
}
func newHashShake256() hash.Hash {
return &state{rate: 136, dsbyte: 0x1f, outputLen: 512}
}
// testDigests contains functions returning hash.Hash instances
// with output-length equal to the KAT length for both SHA-3 and
// SHAKE instances.
var testDigests = map[string]func() hash.Hash{
"SHA3-224": New224,
"SHA3-256": New256,
"SHA3-384": New384,
"SHA3-512": New512,
"SHAKE128": newHashShake128,
"SHAKE256": newHashShake256,
}
// testShakes contains functions that return ShakeHash instances for
// testing the ShakeHash-specific interface.
var testShakes = map[string]func() ShakeHash{
"SHAKE128": NewShake128,
"SHAKE256": NewShake256,
}
// decodeHex converts a hex-encoded string into a raw byte string.
func decodeHex(s string) []byte {
b, err := hex.DecodeString(s)
if err != nil {
panic(err)
}
return b
}
// structs used to marshal JSON test-cases.
type KeccakKats struct {
Kats map[string][]struct {
Digest string `json:"digest"`
Length int64 `json:"length"`
Message string `json:"message"`
}
}
func testUnalignedAndGeneric(t *testing.T, testf func(impl string)) {
xorInOrig, copyOutOrig := xorIn, copyOut
xorIn, copyOut = xorInGeneric, copyOutGeneric
testf("generic")
if xorImplementationUnaligned != "generic" {
xorIn, copyOut = xorInUnaligned, copyOutUnaligned
testf("unaligned")
}
xorIn, copyOut = xorInOrig, copyOutOrig
}
// TestKeccakKats tests the SHA-3 and Shake implementations against all the
// ShortMsgKATs from https://github.com/gvanas/KeccakCodePackage
// (The testvectors are stored in keccakKats.json.deflate due to their length.)
func TestKeccakKats(t *testing.T) {
testUnalignedAndGeneric(t, func(impl string) {
// Read the KATs.
deflated, err := os.Open(katFilename)
if err != nil {
t.Errorf("error opening %s: %s", katFilename, err)
}
file := flate.NewReader(deflated)
dec := json.NewDecoder(file)
var katSet KeccakKats
err = dec.Decode(&katSet)
if err != nil {
t.Errorf("error decoding KATs: %s", err)
}
// Do the KATs.
for functionName, kats := range katSet.Kats {
d := testDigests[functionName]()
for _, kat := range kats {
d.Reset()
in, err := hex.DecodeString(kat.Message)
if err != nil {
t.Errorf("error decoding KAT: %s", err)
}
d.Write(in[:kat.Length/8])
got := strings.ToUpper(hex.EncodeToString(d.Sum(nil)))
if got != kat.Digest {
t.Errorf("function=%s, implementation=%s, length=%d\nmessage:\n %s\ngot:\n %s\nwanted:\n %s",
functionName, impl, kat.Length, kat.Message, got, kat.Digest)
t.Logf("wanted %+v", kat)
t.FailNow()
}
continue
}
}
})
}
// TestUnalignedWrite tests that writing data in an arbitrary pattern with
// small input buffers.
func testUnalignedWrite(t *testing.T) {
testUnalignedAndGeneric(t, func(impl string) {
buf := sequentialBytes(0x10000)
for alg, df := range testDigests {
d := df()
d.Reset()
d.Write(buf)
want := d.Sum(nil)
d.Reset()
for i := 0; i < len(buf); {
// Cycle through offsets which make a 137 byte sequence.
// Because 137 is prime this sequence should exercise all corner cases.
offsets := [17]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 1}
for _, j := range offsets {
if v := len(buf) - i; v < j {
j = v
}
d.Write(buf[i : i+j])
i += j
}
}
got := d.Sum(nil)
if !bytes.Equal(got, want) {
t.Errorf("Unaligned writes, implementation=%s, alg=%s\ngot %q, want %q", impl, alg, got, want)
}
}
})
}
// TestAppend checks that appending works when reallocation is necessary.
func TestAppend(t *testing.T) {
testUnalignedAndGeneric(t, func(impl string) {
d := New224()
for capacity := 2; capacity <= 66; capacity += 64 {
// The first time around the loop, Sum will have to reallocate.
// The second time, it will not.
buf := make([]byte, 2, capacity)
d.Reset()
d.Write([]byte{0xcc})
buf = d.Sum(buf)
expected := "0000DF70ADC49B2E76EEE3A6931B93FA41841C3AF2CDF5B32A18B5478C39"
if got := strings.ToUpper(hex.EncodeToString(buf)); got != expected {
t.Errorf("got %s, want %s", got, expected)
}
}
})
}
// TestAppendNoRealloc tests that appending works when no reallocation is necessary.
func TestAppendNoRealloc(t *testing.T) {
testUnalignedAndGeneric(t, func(impl string) {
buf := make([]byte, 1, 200)
d := New224()
d.Write([]byte{0xcc})
buf = d.Sum(buf)
expected := "00DF70ADC49B2E76EEE3A6931B93FA41841C3AF2CDF5B32A18B5478C39"
if got := strings.ToUpper(hex.EncodeToString(buf)); got != expected {
t.Errorf("%s: got %s, want %s", impl, got, expected)
}
})
}
// TestSqueezing checks that squeezing the full output a single time produces
// the same output as repeatedly squeezing the instance.
func TestSqueezing(t *testing.T) {
testUnalignedAndGeneric(t, func(impl string) {
for functionName, newShakeHash := range testShakes {
d0 := newShakeHash()
d0.Write([]byte(testString))
ref := make([]byte, 32)
d0.Read(ref)
d1 := newShakeHash()
d1.Write([]byte(testString))
var multiple []byte
for range ref {
one := make([]byte, 1)
d1.Read(one)
multiple = append(multiple, one...)
}
if !bytes.Equal(ref, multiple) {
t.Errorf("%s (%s): squeezing %d bytes one at a time failed", functionName, impl, len(ref))
}
}
})
}
// sequentialBytes produces a buffer of size consecutive bytes 0x00, 0x01, ..., used for testing.
func sequentialBytes(size int) []byte {
result := make([]byte, size)
for i := range result {
result[i] = byte(i)
}
return result
}
// BenchmarkPermutationFunction measures the speed of the permutation function
// with no input data.
func BenchmarkPermutationFunction(b *testing.B) {
b.SetBytes(int64(200))
var lanes [25]uint64
for i := 0; i < b.N; i++ {
keccakF1600(&lanes)
}
}
// benchmarkHash tests the speed to hash num buffers of buflen each.
func benchmarkHash(b *testing.B, h hash.Hash, size, num int) {
b.StopTimer()
h.Reset()
data := sequentialBytes(size)
b.SetBytes(int64(size * num))
b.StartTimer()
var state []byte
for i := 0; i < b.N; i++ {
for j := 0; j < num; j++ {
h.Write(data)
}
state = h.Sum(state[:0])
}
b.StopTimer()
h.Reset()
}
// benchmarkShake is specialized to the Shake instances, which don't
// require a copy on reading output.
func benchmarkShake(b *testing.B, h ShakeHash, size, num int) {
b.StopTimer()
h.Reset()
data := sequentialBytes(size)
d := make([]byte, 32)
b.SetBytes(int64(size * num))
b.StartTimer()
for i := 0; i < b.N; i++ {
h.Reset()
for j := 0; j < num; j++ {
h.Write(data)
}
h.Read(d)
}
}
func BenchmarkSha3_512_MTU(b *testing.B) { benchmarkHash(b, New512(), 1350, 1) }
func BenchmarkSha3_384_MTU(b *testing.B) { benchmarkHash(b, New384(), 1350, 1) }
func BenchmarkSha3_256_MTU(b *testing.B) { benchmarkHash(b, New256(), 1350, 1) }
func BenchmarkSha3_224_MTU(b *testing.B) { benchmarkHash(b, New224(), 1350, 1) }
func BenchmarkShake128_MTU(b *testing.B) { benchmarkShake(b, NewShake128(), 1350, 1) }
func BenchmarkShake256_MTU(b *testing.B) { benchmarkShake(b, NewShake256(), 1350, 1) }
func BenchmarkShake256_16x(b *testing.B) { benchmarkShake(b, NewShake256(), 16, 1024) }
func BenchmarkShake256_1MiB(b *testing.B) { benchmarkShake(b, NewShake256(), 1024, 1024) }
func BenchmarkSha3_512_1MiB(b *testing.B) { benchmarkHash(b, New512(), 1024, 1024) }
func Example_sum() {
buf := []byte("some data to hash")
// A hash needs to be 64 bytes long to have 256-bit collision resistance.
h := make([]byte, 64)
// Compute a 64-byte hash of buf and put it in h.
ShakeSum256(h, buf)
}
func Example_mac() {
k := []byte("this is a secret key; you should generate a strong random key that's at least 32 bytes long")
buf := []byte("and this is some data to authenticate")
// A MAC with 32 bytes of output has 256-bit security strength -- if you use at least a 32-byte-long key.
h := make([]byte, 32)
d := NewShake256()
// Write the key into the hash.
d.Write(k)
// Now write the data.
d.Write(buf)
// Read 32 bytes of output from the hash into h.
d.Read(h)
}
