TrueCloudLab/tzhash
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Get rid of unsafe usage and add tests

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This commit is contained in:
Evgenii 2019-06-21 22:29:08 +03:00
parent a967cc9d3d
commit 9485f49f3b
3 changed files with 107 additions and 54 deletions
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54
tz/hash.go
View file

@ -7,7 +7,6 @@ import (
"errors"
"hash"
"math"
"unsafe"
"github.com/nspcc-dev/tzhash/gf127"
)
@ -17,19 +16,12 @@ const (
hashBlockSize = 128
)
type (
digest struct {
type digest struct {
x [4]gf127.GF127
}
digest2 digest
)
// type assertions
var (
_ hash.Hash = new(digest)
_ hash.Hash = new(digest2)
)
// type assertion
var _ hash.Hash = new(digest)
var (
minmax = [2]gf127.GF127{{0, 0}, {math.MaxUint64, math.MaxUint64}}
@ -93,46 +85,11 @@ func (d *digest) BlockSize() int {
return hashBlockSize
}
func (d *digest2) Write(data []byte) (n int, err error) {
n = len(data)
// We need to transpose matrix, because
// mulBitRightx2 accepts matrix by columns, not rows
a := d.x[1]
d.x[1] = d.x[2]
d.x[2] = a
h1 := (*gf127.GF127x2)(unsafe.Pointer(&d.x[0]))
h2 := (*gf127.GF127x2)(unsafe.Pointer(&d.x[2]))
for _, b := range data {
mulBitRightx2(h1, h2, &minmax[(b>>7)&1])
mulBitRightx2(h1, h2, &minmax[(b>>6)&1])
mulBitRightx2(h1, h2, &minmax[(b>>5)&1])
mulBitRightx2(h1, h2, &minmax[(b>>4)&1])
mulBitRightx2(h1, h2, &minmax[(b>>3)&1])
mulBitRightx2(h1, h2, &minmax[(b>>2)&1])
mulBitRightx2(h1, h2, &minmax[(b>>1)&1])
mulBitRightx2(h1, h2, &minmax[(b>>0)&1])
}
// transpose matrix back
a = d.x[1]
d.x[1] = d.x[2]
d.x[2] = a
return
}
func (d *digest2) Sum(b []byte) []byte { return (*digest)(d).Sum(b) }
func (d *digest2) Reset() { (*digest)(d).Reset() }
func (d *digest2) Size() int { return (*digest)(d).Size() }
func (d *digest2) BlockSize() int { return (*digest)(d).BlockSize() }
func (d *digest2) checkSum() [hashSize]byte { return (*digest)(d).checkSum() }
// Sum returnz Tillich-Zémor checksum of data
func Sum(data []byte) [hashSize]byte {
d := new(digest2)
d := new(digest)
d.Reset()
d.Write(data)
_, _ = d.Write(data) // no errors
return d.checkSum()
}
@ -215,4 +172,3 @@ func SubtractL(c, a []byte) (b []byte, err error) {
}
func mulBitRight(c00, c01, c10, c11, e *gf127.GF127)
func mulBitRightx2(c00c01 *gf127.GF127x2, c10c11 *gf127.GF127x2, e *gf127.GF127)

55
tz/hash_avx2.go Normal file
View file

@ -0,0 +1,55 @@
package tz
import (
"hash"
"github.com/nspcc-dev/tzhash/gf127"
)
type digest2 struct {
x [2]gf127.GF127x2
}
var _ hash.Hash = new(digest2)
func (d *digest2) Write(data []byte) (n int, err error) {
n = len(data)
for _, b := range data {
mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>7)&1])
mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>6)&1])
mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>5)&1])
mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>4)&1])
mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>3)&1])
mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>2)&1])
mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>1)&1])
mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>0)&1])
}
return
}
func (d *digest2) Sum(in []byte) []byte {
// Make a copy of d so that caller can keep writing and summing.
d0 := *d
h := d0.checkSum()
return append(in, h[:]...)
}
func (d *digest2) Reset() {
d.x[0] = gf127.GF127x2{1, 0, 0, 0}
d.x[1] = gf127.GF127x2{0, 0, 0, 1}
}
func (d *digest2) Size() int { return hashSize }
func (d *digest2) BlockSize() int { return hashBlockSize }
func (d *digest2) checkSum() (b [hashSize]byte) {
// Matrix is stored transposed,
// but we need to use order consistent with digest.
h := d.x[0].ByteArray()
copy(b[:], h[:8])
copy(b[16:], h[8:])
h = d.x[1].ByteArray()
copy(b[8:], h[:8])
copy(b[24:], h[8:])
return
}
func mulBitRightx2(c00c10 *gf127.GF127x2, c01c11 *gf127.GF127x2, e *gf127.GF127)

48
tz/hash_test.go
View file

@ -8,7 +8,49 @@ import (
"github.com/stretchr/testify/require"
)
var testCases = []struct {
input []byte
hash string
}{
{
[]byte{0, 1, 2, 3, 4, 5, 6, 7, 8},
"00000000000001e4a545e5b90fb6882b00000000000000c849cd88f79307f67100000000000000cd0c898cb68356e624000000000000007cbcdc7c5e89b16e4b",
},
{
[]byte{4, 8, 15, 16, 23, 42, 255, 0, 127, 65, 32, 123, 42, 45, 201, 210, 213, 244},
"4db8a8e253903c70ab0efb65fe6de05a36d1dc9f567a147152d0148a86817b2062908d9b026a506007c1118e86901b672a39317c55ee3c10ac8efafa79efe8ee",
},
}
func TestHash(t *testing.T) {
t.Run("test AVX digest", func(t *testing.T) {
d := new(digest)
for _, tc := range testCases {
d.Reset()
_, _ = d.Write(tc.input)
sum := d.checkSum()
hash := hex.EncodeToString(sum[:])
if hash != tc.hash {
t.Errorf("expected (%s), got (%s)", tc.hash, hash)
}
}
})
t.Run("test AVX2 digest", func(t *testing.T) {
d := new(digest)
for _, tc := range testCases {
d.Reset()
_, _ = d.Write(tc.input)
sum := d.checkSum()
hash := hex.EncodeToString(sum[:])
if hash != tc.hash {
t.Errorf("expected (%s), got (%s)", tc.hash, hash)
}
}
})
}
func TestHomomorphism(t *testing.T) {
var (
c1, c2 sl2
n int
@ -36,7 +78,7 @@ func TestHash(t *testing.T) {
require.Equal(t, h, c1.ByteArray())
}
var testCases = []struct {
var testCasesConcat = []struct {
Hash string
Parts []string
}{{
@ -62,7 +104,7 @@ func TestConcat(t *testing.T) {
err error
)
for _, tc := range testCases {
for _, tc := range testCasesConcat {
expect, err = hex.DecodeString(tc.Hash)
require.NoError(t, err)
@ -86,7 +128,7 @@ func TestValidate(t *testing.T) {
err error
)
for _, tc := range testCases {
for _, tc := range testCasesConcat {
hash, _ = hex.DecodeString(tc.Hash)
require.NoError(t, err)