// 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 // +build amd64 arm64 package elliptic import ( "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]) if got, want := p256Precomputed[i][j*8:(j*8)+8], t1[:8]; !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) } } }