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
|
// Copyright 2011 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.
package ssh
import (
"bytes"
"crypto"
"crypto/rand"
"testing"
)
func TestDefaultCiphersExist(t *testing.T) {
for _, cipherAlgo := range supportedCiphers {
if _, ok := cipherModes[cipherAlgo]; !ok {
t.Errorf("supported cipher %q is unknown", cipherAlgo)
}
}
for _, cipherAlgo := range preferredCiphers {
if _, ok := cipherModes[cipherAlgo]; !ok {
t.Errorf("preferred cipher %q is unknown", cipherAlgo)
}
}
}
func TestPacketCiphers(t *testing.T) {
defaultMac := "hmac-sha2-256"
defaultCipher := "aes128-ctr"
for cipher := range cipherModes {
t.Run("cipher="+cipher,
func(t *testing.T) { testPacketCipher(t, cipher, defaultMac) })
}
for mac := range macModes {
t.Run("mac="+mac,
func(t *testing.T) { testPacketCipher(t, defaultCipher, mac) })
}
}
func testPacketCipher(t *testing.T, cipher, mac string) {
kr := &kexResult{Hash: crypto.SHA1}
algs := directionAlgorithms{
Cipher: cipher,
MAC: mac,
Compression: "none",
}
client, err := newPacketCipher(clientKeys, algs, kr)
if err != nil {
t.Fatalf("newPacketCipher(client, %q, %q): %v", cipher, mac, err)
}
server, err := newPacketCipher(clientKeys, algs, kr)
if err != nil {
t.Fatalf("newPacketCipher(client, %q, %q): %v", cipher, mac, err)
}
want := "bla bla"
input := []byte(want)
buf := &bytes.Buffer{}
if err := client.writePacket(0, buf, rand.Reader, input); err != nil {
t.Fatalf("writePacket(%q, %q): %v", cipher, mac, err)
}
packet, err := server.readPacket(0, buf)
if err != nil {
t.Fatalf("readPacket(%q, %q): %v", cipher, mac, err)
}
if string(packet) != want {
t.Errorf("roundtrip(%q, %q): got %q, want %q", cipher, mac, packet, want)
}
}
func TestCBCOracleCounterMeasure(t *testing.T) {
kr := &kexResult{Hash: crypto.SHA1}
algs := directionAlgorithms{
Cipher: aes128cbcID,
MAC: "hmac-sha1",
Compression: "none",
}
client, err := newPacketCipher(clientKeys, algs, kr)
if err != nil {
t.Fatalf("newPacketCipher(client): %v", err)
}
want := "bla bla"
input := []byte(want)
buf := &bytes.Buffer{}
if err := client.writePacket(0, buf, rand.Reader, input); err != nil {
t.Errorf("writePacket: %v", err)
}
packetSize := buf.Len()
buf.Write(make([]byte, 2*maxPacket))
// We corrupt each byte, but this usually will only test the
// 'packet too large' or 'MAC failure' cases.
lastRead := -1
for i := 0; i < packetSize; i++ {
server, err := newPacketCipher(clientKeys, algs, kr)
if err != nil {
t.Fatalf("newPacketCipher(client): %v", err)
}
fresh := &bytes.Buffer{}
fresh.Write(buf.Bytes())
fresh.Bytes()[i] ^= 0x01
before := fresh.Len()
_, err = server.readPacket(0, fresh)
if err == nil {
t.Errorf("corrupt byte %d: readPacket succeeded ", i)
continue
}
if _, ok := err.(cbcError); !ok {
t.Errorf("corrupt byte %d: got %v (%T), want cbcError", i, err, err)
continue
}
after := fresh.Len()
bytesRead := before - after
if bytesRead < maxPacket {
t.Errorf("corrupt byte %d: read %d bytes, want more than %d", i, bytesRead, maxPacket)
continue
}
if i > 0 && bytesRead != lastRead {
t.Errorf("corrupt byte %d: read %d bytes, want %d bytes read", i, bytesRead, lastRead)
}
lastRead = bytesRead
}
}
|
