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
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
|
<?php
/**
* OpenSSH Key Handler
*
* PHP version 5
*
* Place in $HOME/.ssh/authorized_keys
*
* @author Jim Wigginton <[email protected]>
* @copyright 2015 Jim Wigginton
* @license http://www.opensource.org/licenses/mit-license.html MIT License
* @link http://phpseclib.sourceforge.net
*/
namespace phpseclib3\Crypt\Common\Formats\Keys;
use phpseclib3\Common\Functions\Strings;
use phpseclib3\Crypt\AES;
use phpseclib3\Crypt\Random;
/**
* OpenSSH Formatted RSA Key Handler
*
* @author Jim Wigginton <[email protected]>
*/
abstract class OpenSSH
{
/**
* Default comment
*
* @var string
*/
protected static $comment = 'phpseclib-generated-key';
/**
* Binary key flag
*
* @var bool
*/
protected static $binary = false;
/**
* Sets the default comment
*
* @param string $comment
*/
public static function setComment($comment)
{
self::$comment = str_replace(["\r", "\n"], '', $comment);
}
/**
* Break a public or private key down into its constituent components
*
* $type can be either ssh-dss or ssh-rsa
*
* @param string $key
* @param string $password
* @return array
*/
public static function load($key, $password = '')
{
if (!Strings::is_stringable($key)) {
throw new \UnexpectedValueException('Key should be a string - not a ' . gettype($key));
}
// key format is described here:
// https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/PROTOCOL.key?annotate=HEAD
if (strpos($key, 'BEGIN OPENSSH PRIVATE KEY') !== false) {
$key = preg_replace('#(?:^-.*?-[\r\n]*$)|\s#ms', '', $key);
$key = Strings::base64_decode($key);
$magic = Strings::shift($key, 15);
if ($magic != "openssh-key-v1\0") {
throw new \RuntimeException('Expected openssh-key-v1');
}
list($ciphername, $kdfname, $kdfoptions, $numKeys) = Strings::unpackSSH2('sssN', $key);
if ($numKeys != 1) {
// if we wanted to support multiple keys we could update PublicKeyLoader to preview what the # of keys
// would be; it'd then call Common\Keys\OpenSSH.php::load() and get the paddedKey. it'd then pass
// that to the appropriate key loading parser $numKey times or something
throw new \RuntimeException('Although the OpenSSH private key format supports multiple keys phpseclib does not');
}
switch ($ciphername) {
case 'none':
break;
case 'aes256-ctr':
if ($kdfname != 'bcrypt') {
throw new \RuntimeException('Only the bcrypt kdf is supported (' . $kdfname . ' encountered)');
}
list($salt, $rounds) = Strings::unpackSSH2('sN', $kdfoptions);
$crypto = new AES('ctr');
//$crypto->setKeyLength(256);
//$crypto->disablePadding();
$crypto->setPassword($password, 'bcrypt', $salt, $rounds, 32);
break;
default:
throw new \RuntimeException('The only supported cipherse are: none, aes256-ctr (' . $ciphername . ' is being used)');
}
list($publicKey, $paddedKey) = Strings::unpackSSH2('ss', $key);
list($type) = Strings::unpackSSH2('s', $publicKey);
if (isset($crypto)) {
$paddedKey = $crypto->decrypt($paddedKey);
}
list($checkint1, $checkint2) = Strings::unpackSSH2('NN', $paddedKey);
// any leftover bytes in $paddedKey are for padding? but they should be sequential bytes. eg. 1, 2, 3, etc.
if ($checkint1 != $checkint2) {
throw new \RuntimeException('The two checkints do not match');
}
self::checkType($type);
return compact('type', 'publicKey', 'paddedKey');
}
$parts = explode(' ', $key, 3);
if (!isset($parts[1])) {
$key = base64_decode($parts[0]);
$comment = false;
} else {
$asciiType = $parts[0];
self::checkType($parts[0]);
$key = base64_decode($parts[1]);
$comment = isset($parts[2]) ? $parts[2] : false;
}
if ($key === false) {
throw new \UnexpectedValueException('Key should be a string - not a ' . gettype($key));
}
list($type) = Strings::unpackSSH2('s', $key);
self::checkType($type);
if (isset($asciiType) && $asciiType != $type) {
throw new \RuntimeException('Two different types of keys are claimed: ' . $asciiType . ' and ' . $type);
}
if (strlen($key) <= 4) {
throw new \UnexpectedValueException('Key appears to be malformed');
}
$publicKey = $key;
return compact('type', 'publicKey', 'comment');
}
/**
* Toggle between binary and printable keys
*
* Printable keys are what are generated by default. These are the ones that go in
* $HOME/.ssh/authorized_key.
*
* @param bool $enabled
*/
public static function setBinaryOutput($enabled)
{
self::$binary = $enabled;
}
/**
* Checks to see if the type is valid
*
* @param string $candidate
*/
private static function checkType($candidate)
{
if (!in_array($candidate, static::$types)) {
throw new \RuntimeException("The key type ($candidate) is not equal to: " . implode(',', static::$types));
}
}
/**
* Wrap a private key appropriately
*
* @param string $publicKey
* @param string $privateKey
* @param string $password
* @param array $options
* @return string
*/
protected static function wrapPrivateKey($publicKey, $privateKey, $password, $options)
{
list(, $checkint) = unpack('N', Random::string(4));
$comment = isset($options['comment']) ? $options['comment'] : self::$comment;
$paddedKey = Strings::packSSH2('NN', $checkint, $checkint) .
$privateKey .
Strings::packSSH2('s', $comment);
$usesEncryption = !empty($password) && is_string($password);
/*
from http://tools.ietf.org/html/rfc4253#section-6 :
Note that the length of the concatenation of 'packet_length',
'padding_length', 'payload', and 'random padding' MUST be a multiple
of the cipher block size or 8, whichever is larger.
*/
$blockSize = $usesEncryption ? 16 : 8;
$paddingLength = (($blockSize - 1) * strlen($paddedKey)) % $blockSize;
for ($i = 1; $i <= $paddingLength; $i++) {
$paddedKey .= chr($i);
}
if (!$usesEncryption) {
$key = Strings::packSSH2('sssNss', 'none', 'none', '', 1, $publicKey, $paddedKey);
} else {
$rounds = isset($options['rounds']) ? $options['rounds'] : 16;
$salt = Random::string(16);
$kdfoptions = Strings::packSSH2('sN', $salt, $rounds);
$crypto = new AES('ctr');
$crypto->setPassword($password, 'bcrypt', $salt, $rounds, 32);
$paddedKey = $crypto->encrypt($paddedKey);
$key = Strings::packSSH2('sssNss', 'aes256-ctr', 'bcrypt', $kdfoptions, 1, $publicKey, $paddedKey);
}
$key = "openssh-key-v1\0$key";
return "-----BEGIN OPENSSH PRIVATE KEY-----\n" .
chunk_split(Strings::base64_encode($key), 70, "\n") .
"-----END OPENSSH PRIVATE KEY-----\n";
}
}
|
