dsa_test.go

Documentation: crypto/dsa

		 1  // Copyright 2011 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 dsa
		 6  
		 7  import (
		 8  	"crypto/rand"
		 9  	"math/big"
		10  	"testing"
		11  )
		12  
		13  func testSignAndVerify(t *testing.T, i int, priv *PrivateKey) {
		14  	hashed := []byte("testing")
		15  	r, s, err := Sign(rand.Reader, priv, hashed)
		16  	if err != nil {
		17  		t.Errorf("%d: error signing: %s", i, err)
		18  		return
		19  	}
		20  
		21  	if !Verify(&priv.PublicKey, hashed, r, s) {
		22  		t.Errorf("%d: Verify failed", i)
		23  	}
		24  }
		25  
		26  func testParameterGeneration(t *testing.T, sizes ParameterSizes, L, N int) {
		27  	var priv PrivateKey
		28  	params := &priv.Parameters
		29  
		30  	err := GenerateParameters(params, rand.Reader, sizes)
		31  	if err != nil {
		32  		t.Errorf("%d: %s", int(sizes), err)
		33  		return
		34  	}
		35  
		36  	if params.P.BitLen() != L {
		37  		t.Errorf("%d: params.BitLen got:%d want:%d", int(sizes), params.P.BitLen(), L)
		38  	}
		39  
		40  	if params.Q.BitLen() != N {
		41  		t.Errorf("%d: q.BitLen got:%d want:%d", int(sizes), params.Q.BitLen(), L)
		42  	}
		43  
		44  	one := new(big.Int)
		45  	one.SetInt64(1)
		46  	pm1 := new(big.Int).Sub(params.P, one)
		47  	quo, rem := new(big.Int).DivMod(pm1, params.Q, new(big.Int))
		48  	if rem.Sign() != 0 {
		49  		t.Errorf("%d: p-1 mod q != 0", int(sizes))
		50  	}
		51  	x := new(big.Int).Exp(params.G, quo, params.P)
		52  	if x.Cmp(one) == 0 {
		53  		t.Errorf("%d: invalid generator", int(sizes))
		54  	}
		55  
		56  	err = GenerateKey(&priv, rand.Reader)
		57  	if err != nil {
		58  		t.Errorf("error generating key: %s", err)
		59  		return
		60  	}
		61  
		62  	testSignAndVerify(t, int(sizes), &priv)
		63  }
		64  
		65  func TestParameterGeneration(t *testing.T) {
		66  	if testing.Short() {
		67  		t.Skip("skipping parameter generation test in short mode")
		68  	}
		69  
		70  	testParameterGeneration(t, L1024N160, 1024, 160)
		71  	testParameterGeneration(t, L2048N224, 2048, 224)
		72  	testParameterGeneration(t, L2048N256, 2048, 256)
		73  	testParameterGeneration(t, L3072N256, 3072, 256)
		74  }
		75  
		76  func fromHex(s string) *big.Int {
		77  	result, ok := new(big.Int).SetString(s, 16)
		78  	if !ok {
		79  		panic(s)
		80  	}
		81  	return result
		82  }
		83  
		84  func TestSignAndVerify(t *testing.T) {
		85  	priv := PrivateKey{
		86  		PublicKey: PublicKey{
		87  			Parameters: Parameters{
		88  				P: fromHex("A9B5B793FB4785793D246BAE77E8FF63CA52F442DA763C440259919FE1BC1D6065A9350637A04F75A2F039401D49F08E066C4D275A5A65DA5684BC563C14289D7AB8A67163BFBF79D85972619AD2CFF55AB0EE77A9002B0EF96293BDD0F42685EBB2C66C327079F6C98000FBCB79AACDE1BC6F9D5C7B1A97E3D9D54ED7951FEF"),
		89  				Q: fromHex("E1D3391245933D68A0714ED34BBCB7A1F422B9C1"),
		90  				G: fromHex("634364FC25248933D01D1993ECABD0657CC0CB2CEED7ED2E3E8AECDFCDC4A25C3B15E9E3B163ACA2984B5539181F3EFF1A5E8903D71D5B95DA4F27202B77D2C44B430BB53741A8D59A8F86887525C9F2A6A5980A195EAA7F2FF910064301DEF89D3AA213E1FAC7768D89365318E370AF54A112EFBA9246D9158386BA1B4EEFDA"),
		91  			},
		92  			Y: fromHex("32969E5780CFE1C849A1C276D7AEB4F38A23B591739AA2FE197349AEEBD31366AEE5EB7E6C6DDB7C57D02432B30DB5AA66D9884299FAA72568944E4EEDC92EA3FBC6F39F53412FBCC563208F7C15B737AC8910DBC2D9C9B8C001E72FDC40EB694AB1F06A5A2DBD18D9E36C66F31F566742F11EC0A52E9F7B89355C02FB5D32D2"),
		93  		},
		94  		X: fromHex("5078D4D29795CBE76D3AACFE48C9AF0BCDBEE91A"),
		95  	}
		96  
		97  	testSignAndVerify(t, 0, &priv)
		98  }
		99  
	 100  func TestSignAndVerifyWithBadPublicKey(t *testing.T) {
	 101  	pub := PublicKey{
	 102  		Parameters: Parameters{
	 103  			P: fromHex("A9B5B793FB4785793D246BAE77E8FF63CA52F442DA763C440259919FE1BC1D6065A9350637A04F75A2F039401D49F08E066C4D275A5A65DA5684BC563C14289D7AB8A67163BFBF79D85972619AD2CFF55AB0EE77A9002B0EF96293BDD0F42685EBB2C66C327079F6C98000FBCB79AACDE1BC6F9D5C7B1A97E3D9D54ED7951FEF"),
	 104  			Q: fromHex("FA"),
	 105  			G: fromHex("634364FC25248933D01D1993ECABD0657CC0CB2CEED7ED2E3E8AECDFCDC4A25C3B15E9E3B163ACA2984B5539181F3EFF1A5E8903D71D5B95DA4F27202B77D2C44B430BB53741A8D59A8F86887525C9F2A6A5980A195EAA7F2FF910064301DEF89D3AA213E1FAC7768D89365318E370AF54A112EFBA9246D9158386BA1B4EEFDA"),
	 106  		},
	 107  		Y: fromHex("32969E5780CFE1C849A1C276D7AEB4F38A23B591739AA2FE197349AEEBD31366AEE5EB7E6C6DDB7C57D02432B30DB5AA66D9884299FAA72568944E4EEDC92EA3FBC6F39F53412FBCC563208F7C15B737AC8910DBC2D9C9B8C001E72FDC40EB694AB1F06A5A2DBD18D9E36C66F31F566742F11EC0A52E9F7B89355C02FB5D32D2"),
	 108  	}
	 109  
	 110  	if Verify(&pub, []byte("testing"), fromHex("2"), fromHex("4")) {
	 111  		t.Errorf("Verify unexpected success with non-existent mod inverse of Q")
	 112  	}
	 113  }
	 114  
	 115  func TestSigningWithDegenerateKeys(t *testing.T) {
	 116  	// Signing with degenerate private keys should not cause an infinite
	 117  	// loop.
	 118  	badKeys := []struct {
	 119  		p, q, g, y, x string
	 120  	}{
	 121  		{"00", "01", "00", "00", "00"},
	 122  		{"01", "ff", "00", "00", "00"},
	 123  	}
	 124  
	 125  	for i, test := range badKeys {
	 126  		priv := PrivateKey{
	 127  			PublicKey: PublicKey{
	 128  				Parameters: Parameters{
	 129  					P: fromHex(test.p),
	 130  					Q: fromHex(test.q),
	 131  					G: fromHex(test.g),
	 132  				},
	 133  				Y: fromHex(test.y),
	 134  			},
	 135  			X: fromHex(test.x),
	 136  		}
	 137  
	 138  		hashed := []byte("testing")
	 139  		if _, _, err := Sign(rand.Reader, &priv, hashed); err == nil {
	 140  			t.Errorf("#%d: unexpected success", i)
	 141  		}
	 142  	}
	 143  }
	 144
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