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
5package dsa
6
7import (
8	"crypto/rand"
9	"math/big"
10	"testing"
11)
12
13func 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
26func 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
65func 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
76func 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
84func 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
100func 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
115func 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