| // 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) |
| } |
| } |
| |
| } |
