Home | History | Annotate | Download | only in elliptic 
      1 // Copyright 2012 The Go Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style
      3 // license that can be found in the LICENSE file.
      4 
      5 package elliptic
      6 
      7 import (
      8 	"math/big"
      9 	"testing"
     10 )
     11 
     12 var toFromBigTests = []string{
     13 	"0",
     14 	"1",
     15 	"23",
     16 	"b70e0cb46bb4bf7f321390b94a03c1d356c01122343280d6105c1d21",
     17 	"706a46d476dcb76798e6046d89474788d164c18032d268fd10704fa6",
     18 }
     19 
     20 func p224AlternativeToBig(in *p224FieldElement) *big.Int {
     21 	ret := new(big.Int)
     22 	tmp := new(big.Int)
     23 
     24 	for i := uint(0); i < 8; i++ {
     25 		tmp.SetInt64(int64(in[i]))
     26 		tmp.Lsh(tmp, 28*i)
     27 		ret.Add(ret, tmp)
     28 	}
     29 	ret.Mod(ret, p224.P)
     30 	return ret
     31 }
     32 
     33 func TestToFromBig(t *testing.T) {
     34 	for i, test := range toFromBigTests {
     35 		n, _ := new(big.Int).SetString(test, 16)
     36 		var x p224FieldElement
     37 		p224FromBig(&x, n)
     38 		m := p224ToBig(&x)
     39 		if n.Cmp(m) != 0 {
     40 			t.Errorf("#%d: %x != %x", i, n, m)
     41 		}
     42 		q := p224AlternativeToBig(&x)
     43 		if n.Cmp(q) != 0 {
     44 			t.Errorf("#%d: %x != %x (alternative)", i, n, m)
     45 		}
     46 	}
     47 }
     48