/
CsrfProtectionMiddleware.php
238 lines (214 loc) · 7.88 KB
/
CsrfProtectionMiddleware.php
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
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
<?php
/**
* CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
* Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
*
* Licensed under The MIT License
* For full copyright and license information, please see the LICENSE.txt
* Redistributions of files must retain the above copyright notice.
*
* @copyright Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
* @link http://cakephp.org CakePHP(tm) Project
* @since 3.5.0
* @license http://www.opensource.org/licenses/mit-license.php MIT License
*/
namespace Cake\Http\Middleware;
use Cake\Http\Cookie\Cookie;
use Cake\Http\Exception\InvalidCsrfTokenException;
use Cake\Http\Response;
use Cake\Http\ServerRequest;
use Cake\I18n\Time;
use Cake\Utility\Hash;
use Cake\Utility\Security;
/**
* Provides CSRF protection & validation.
*
* This middleware adds a CSRF token to a cookie. The cookie value is compared to
* request data, or the X-CSRF-Token header on each PATCH, POST,
* PUT, or DELETE request.
*
* If the request data is missing or does not match the cookie data,
* an InvalidCsrfTokenException will be raised.
*
* This middleware integrates with the FormHelper automatically and when
* used together your forms will have CSRF tokens automatically added
* when `$this->Form->create(...)` is used in a view.
*/
class CsrfProtectionMiddleware
{
/**
* Default config for the CSRF handling.
*
* - `cookieName` The name of the cookie to send.
* - `expiry` A strotime compatible value of how long the CSRF token should last.
* Defaults to browser session.
* - `secure` Whether or not the cookie will be set with the Secure flag. Defaults to false.
* - `httpOnly` Whether or not the cookie will be set with the HttpOnly flag. Defaults to false.
* - `samesite` Value for "SameSite" attribute. Default to null.
* - `field` The form field to check. Changing this will also require configuring
* FormHelper.
*
* @var array
*/
protected $_defaultConfig = [
'cookieName' => 'csrfToken',
'expiry' => 0,
'secure' => false,
'httpOnly' => false,
'samesite' => null,
'field' => '_csrfToken',
];
/**
* Configuration
*
* @var array
*/
protected $_config = [];
/**
* Callback for deciding whether or not to skip the token check for particular request.
*
* CSRF protection token check will be skipped if the callback returns `true`.
*
* @var callable|null
*/
protected $whitelistCallback;
/**
* Constructor
*
* @param array $config Config options. See $_defaultConfig for valid keys.
*/
public function __construct(array $config = [])
{
$this->_config = $config + $this->_defaultConfig;
}
/**
* Checks and sets the CSRF token depending on the HTTP verb.
*
* @param \Cake\Http\ServerRequest $request The request.
* @param \Cake\Http\Response $response The response.
* @param callable $next Callback to invoke the next middleware.
* @return \Cake\Http\Response A response
*/
public function __invoke(ServerRequest $request, Response $response, $next)
{
if (
$this->whitelistCallback !== null
&& call_user_func($this->whitelistCallback, $request) === true
) {
return $next($request, $response);
}
$cookies = $request->getCookieParams();
$cookieData = Hash::get($cookies, $this->_config['cookieName']);
if (is_string($cookieData) && strlen($cookieData) > 0) {
$params = $request->getAttribute('params');
$params['_csrfToken'] = $cookieData;
$request = $request->withAttribute('params', $params);
}
$method = $request->getMethod();
if ($method === 'GET' && $cookieData === null) {
$token = $this->_createToken();
$request = $this->_addTokenToRequest($token, $request);
$response = $this->_addTokenCookie($token, $request, $response);
return $next($request, $response);
}
$request = $this->_validateAndUnsetTokenField($request);
return $next($request, $response);
}
/**
* Set callback for allowing to skip token check for particular request.
*
* The callback will receive request instance as argument and must return
* `true` if you want to skip token check for the current request.
*
* @param callable $callback A callable.
* @return $this
*/
public function whitelistCallback(callable $callback)
{
$this->whitelistCallback = $callback;
return $this;
}
/**
* Checks if the request is POST, PUT, DELETE or PATCH and validates the CSRF token
*
* @param \Cake\Http\ServerRequest $request The request object.
* @return \Cake\Http\ServerRequest
*/
protected function _validateAndUnsetTokenField(ServerRequest $request)
{
if (in_array($request->getMethod(), ['PUT', 'POST', 'DELETE', 'PATCH'], true) || $request->getData()) {
$this->_validateToken($request);
$body = $request->getParsedBody();
if (is_array($body)) {
unset($body[$this->_config['field']]);
$request = $request->withParsedBody($body);
}
}
return $request;
}
/**
* Create a new token to be used for CSRF protection
*
* @return string
*/
protected function _createToken()
{
return hash('sha512', Security::randomBytes(16), false);
}
/**
* Add a CSRF token to the request parameters.
*
* @param string $token The token to add.
* @param \Cake\Http\ServerRequest $request The request to augment
* @return \Cake\Http\ServerRequest Modified request
*/
protected function _addTokenToRequest($token, ServerRequest $request)
{
$params = $request->getAttribute('params');
$params['_csrfToken'] = $token;
return $request->withAttribute('params', $params);
}
/**
* Add a CSRF token to the response cookies.
*
* @param string $token The token to add.
* @param \Cake\Http\ServerRequest $request The request to validate against.
* @param \Cake\Http\Response $response The response.
* @return \Cake\Http\Response $response Modified response.
*/
protected function _addTokenCookie($token, ServerRequest $request, Response $response)
{
$expiry = new Time($this->_config['expiry']);
$cookie = new Cookie(
$this->_config['cookieName'],
$token,
$expiry,
$request->getAttribute('webroot'),
'',
(bool)$this->_config['secure'],
(bool)$this->_config['httpOnly'],
isset($this->_config['samesite']) ? $this->_config['samesite'] : $this->_defaultConfig['samesite']
);
return $response->withCookie($cookie);
}
/**
* Validate the request data against the cookie token.
*
* @param \Cake\Http\ServerRequest $request The request to validate against.
* @return void
* @throws \Cake\Http\Exception\InvalidCsrfTokenException When the CSRF token is invalid or missing.
*/
protected function _validateToken(ServerRequest $request)
{
$cookies = $request->getCookieParams();
$cookie = Hash::get($cookies, $this->_config['cookieName']);
$post = Hash::get($request->getParsedBody(), $this->_config['field']);
$header = $request->getHeaderLine('X-CSRF-Token');
if (!$cookie) {
throw new InvalidCsrfTokenException(__d('cake', 'Missing CSRF token cookie'));
}
if (!Security::constantEquals($post, $cookie) && !Security::constantEquals($header, $cookie)) {
throw new InvalidCsrfTokenException(__d('cake', 'CSRF token mismatch.'));
}
}
}