1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
|
// +build go1.5
// = go 1.5 or higher
//
// We compare against Go's built-in GCM implementation. Since stupidgcm only
// supports 128-bit IVs and Go only supports that from 1.5 onward, we cannot
// run these tests on older Go versions.
package stupidgcm
import (
"bytes"
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/hex"
"testing"
"github.com/rfjakob/gcmsiv"
)
// Get "n" random bytes from /dev/urandom or panic
func randBytes(n int) []byte {
b := make([]byte, n)
_, err := rand.Read(b)
if err != nil {
panic("Failed to read random bytes: " + err.Error())
}
return b
}
// TestEncryptDecrypt encrypts and decrypts using both stupidgcm and Go's built-in
// GCM implemenatation and verifies that the results are identical.
func TestEncryptDecrypt(t *testing.T) {
key := randBytes(32)
sGCM := New(key)
authData := randBytes(24)
iv := randBytes(16)
dst := make([]byte, 71) // 71 = random length
gAES, err := aes.NewCipher(key)
if err != nil {
t.Fatal(err)
}
gGCM, err := cipher.NewGCMWithNonceSize(gAES, 16)
if err != nil {
t.Fatal(err)
}
// Check all block sizes from 1 to 5000
for i := 1; i < 5000; i++ {
in := make([]byte, i)
sOut := sGCM.Seal(dst, iv, in, authData)
gOut := gGCM.Seal(dst, iv, in, authData)
// Ciphertext must be identical to Go GCM
if !bytes.Equal(sOut, gOut) {
t.Fatalf("Compare failed for encryption, size %d", i)
t.Log("sOut:")
t.Log("\n" + hex.Dump(sOut))
t.Log("gOut:")
t.Log("\n" + hex.Dump(gOut))
}
sOut2, sErr := sGCM.Open(dst, iv, sOut[len(dst):], authData)
if sErr != nil {
t.Fatal(sErr)
}
gOut2, gErr := gGCM.Open(dst, iv, gOut[len(dst):], authData)
if gErr != nil {
t.Fatal(gErr)
}
// Plaintext must be identical to Go GCM
if !bytes.Equal(sOut2, gOut2) {
t.Fatalf("Compare failed for decryption, size %d", i)
}
}
}
// TestCorruption verifies that changes in the ciphertext result in a decryption
// error
func TestCorruption(t *testing.T) {
key := randBytes(32)
sGCM := New(key)
authData := randBytes(24)
iv := randBytes(16)
in := make([]byte, 354)
sOut := sGCM.Seal(nil, iv, in, authData)
sOut2, sErr := sGCM.Open(nil, iv, sOut, authData)
if sErr != nil {
t.Fatal(sErr)
}
if !bytes.Equal(in, sOut2) {
t.Fatalf("Compare failed")
}
// Corrupt first byte
sOut[0]++
sOut2, sErr = sGCM.Open(nil, iv, sOut, authData)
if sErr == nil || sOut2 != nil {
t.Fatalf("Should have gotten error")
}
sOut[0]--
// Corrupt last byte
sOut[len(sOut)-1]++
sOut2, sErr = sGCM.Open(nil, iv, sOut, authData)
if sErr == nil || sOut2 != nil {
t.Fatalf("Should have gotten error")
}
sOut[len(sOut)-1]--
// Append one byte
sOut = append(sOut, 0)
sOut2, sErr = sGCM.Open(nil, iv, sOut, authData)
if sErr == nil || sOut2 != nil {
t.Fatalf("Should have gotten error")
}
}
// $ go test -bench .
// PASS
// Benchmark4kEncStupidGCM-2 50000 25622 ns/op 159.86 MB/s
// Benchmark4kEncGoGCM-2 10000 116544 ns/op 35.15 MB/s
// ok github.com/rfjakob/gocryptfs/internal/stupidgcm 3.775s
func Benchmark4kEncStupidGCM(b *testing.B) {
key := randBytes(32)
authData := randBytes(24)
iv := randBytes(16)
in := make([]byte, 4096)
b.SetBytes(int64(len(in)))
sGCM := New(key)
for i := 0; i < b.N; i++ {
// Encrypt and append to nonce
sGCM.Seal(iv, iv, in, authData)
}
}
func Benchmark4kEncGoGCM(b *testing.B) {
key := randBytes(32)
authData := randBytes(24)
iv := randBytes(16)
in := make([]byte, 4096)
b.SetBytes(int64(len(in)))
gAES, err := aes.NewCipher(key)
if err != nil {
b.Fatal(err)
}
gGCM, err := cipher.NewGCMWithNonceSize(gAES, 16)
if err != nil {
b.Fatal(err)
}
for i := 0; i < b.N; i++ {
// Encrypt and append to nonce
gGCM.Seal(iv, iv, in, authData)
}
}
func Benchmark4kEncGCMSIV(b *testing.B) {
key := randBytes(32)
authData := randBytes(24)
iv := randBytes(16)
in := make([]byte, 4096)
b.SetBytes(int64(len(in)))
gGCM, err := gcmsiv.NewGCMSIV(key)
if err != nil {
b.Fatal(err)
}
for i := 0; i < b.N; i++ {
// Encrypt and append to nonce
gGCM.Seal(iv, iv, in, authData)
}
}
|
