blob: 6abd8cb11bc5ab21c9dea568729de1a2daf76758 [file] [log] [blame]
// Copyright 2021 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 amd64 || arm64
package elliptic
import (
"encoding/binary"
"reflect"
"testing"
)
func TestP256PrecomputedTable(t *testing.T) {
basePoint := []uint64{
0x79e730d418a9143c, 0x75ba95fc5fedb601, 0x79fb732b77622510, 0x18905f76a53755c6,
0xddf25357ce95560a, 0x8b4ab8e4ba19e45c, 0xd2e88688dd21f325, 0x8571ff1825885d85,
0x0000000000000001, 0xffffffff00000000, 0xffffffffffffffff, 0x00000000fffffffe,
}
t1 := make([]uint64, 12)
t2 := make([]uint64, 12)
copy(t2, basePoint)
zInv := make([]uint64, 4)
zInvSq := make([]uint64, 4)
for j := 0; j < 32; j++ {
copy(t1, t2)
for i := 0; i < 43; i++ {
// The window size is 6 so we need to double 6 times.
if i != 0 {
for k := 0; k < 6; k++ {
p256PointDoubleAsm(t1, t1)
}
}
// Convert the point to affine form. (Its values are
// still in Montgomery form however.)
p256Inverse(zInv, t1[8:12])
p256Sqr(zInvSq, zInv, 1)
p256Mul(zInv, zInv, zInvSq)
p256Mul(t1[:4], t1[:4], zInvSq)
p256Mul(t1[4:8], t1[4:8], zInv)
copy(t1[8:12], basePoint[8:12])
buf := make([]byte, 8*8)
for i, u := range t1[:8] {
binary.LittleEndian.PutUint64(buf[i*8:i*8+8], u)
}
start := i*32*8*8 + j*8*8
if got, want := p256Precomputed[start:start+64], string(buf); !reflect.DeepEqual(got, want) {
t.Fatalf("Unexpected table entry at [%d][%d:%d]: got %v, want %v", i, j*8, (j*8)+8, got, want)
}
}
if j == 0 {
p256PointDoubleAsm(t2, basePoint)
} else {
p256PointAddAsm(t2, t2, basePoint)
}
}
}