blob: cba455d32db965dc2a61cd2bcb1aafaa1b818c40 [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 !purego && (amd64 || arm64 || ppc64le || s390x)
package nistec
import (
"fmt"
"testing"
)
func TestP256PrecomputedTable(t *testing.T) {
base := NewP256Point().SetGenerator()
for i := 0; i < 43; i++ {
t.Run(fmt.Sprintf("table[%d]", i), func(t *testing.T) {
testP256AffineTable(t, base, &p256Precomputed[i])
})
for k := 0; k < 6; k++ {
base.Double(base)
}
}
}
func testP256AffineTable(t *testing.T, base *P256Point, table *p256AffineTable) {
p := NewP256Point()
zInv := new(p256Element)
zInvSq := new(p256Element)
for j := 0; j < 32; j++ {
p.Add(p, base)
// Convert p to affine coordinates.
p256Inverse(zInv, &p.z)
p256Sqr(zInvSq, zInv, 1)
p256Mul(zInv, zInv, zInvSq)
p256Mul(&p.x, &p.x, zInvSq)
p256Mul(&p.y, &p.y, zInv)
p.z = p256One
if p256Equal(&table[j].x, &p.x) != 1 || p256Equal(&table[j].y, &p.y) != 1 {
t.Fatalf("incorrect table entry at index %d", j)
}
}
}