Csrf::__construct() - Code Metrics - Inspection of "CSRF fixes" - oscarotero/psr7-middlewares - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 345022...5c5fe2 )

by Oscar

created 2016-01-13 08:28 UTC

Csrf::__construct() A

↳ Parent: Csrf

Complexity

Conditions	4
Paths	4

Size

Total Lines	10
Code Lines	7

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	1	Features	0

Metric	Value
c	1
b	1
f	0
dl	0
loc	10
rs	9.2
cc	4
eloc	7
nc	4
nop	1

<?php

namespace Psr7Middlewares\Middleware;

use Psr7Middlewares\Middleware;
use Psr7Middlewares\Utils;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Message\ResponseInterface;
use RuntimeException;
use ArrayAccess;

/**
 * Middleware for CSRF protection
 * Code inspired from https://github.com/paragonie/anti-csrf.
 */
class Csrf
{
    use Utils\FormTrait;

    /**
     * @var int Max number of CSRF tokens
     */
    private $maxTokens = 100;

    /**
     * @var string field name with the CSRF index
     */
    private $formIndex = '_CSRF_INDEX';

    /**
     * @var string field name with the CSRF token
     */
    private $formToken = '_CSRF_TOKEN';

    /*
     * @var array|ArrayAccess CSRF storage
     */
    private $storage;

    /**
     * @var string Index used in the storage
     */
    private $sessionIndex = 'CSRF';

    /**
     * Set the storage of the CSRF
     * 
     * @param array|ArrayAccess|null $storage
     */
    public function __construct(&$storage = null)
    {
        if (is_array($storage)) {
            $this->storage = &$storage;
        } elseif ($storage instanceof ArrayAccess) {
            $this->storage = $storage;
        } elseif ($storage !== null) {
            throw new InvalidArgumentException('The storage argument must be an array, ArrayAccess or null');
        }
    }

    /**
     * Execute the middleware.
     *
     * @param ServerRequestInterface $request
     * @param ResponseInterface      $response
     * @param callable               $next
     *
     * @return ResponseInterface
     */
    public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next)
// Bad
class Router
{
    public function generate($path)
    {
        return $_SERVER['HOST'].$path;
    }
}

// Better
class Router
{
    private $host;

    public function __construct($host)
    {
        $this->host = $host;
    }

    public function generate($path)
    {
        return $this->host.$path;
    }
}

class Controller
{
    public function myAction(Request $request)
    {
        // Instead of
        $page = isset($_GET['page']) ? intval($_GET['page']) : 1;

        // Better (assuming you use the Symfony2 request)
        $page = $request->query->get('page', 1);
    }
}
    {
        if (!Middleware::hasAttribute($request, FormatNegotiator::KEY)) {
            throw new RuntimeException('Csrf middleware needs FormatNegotiator executed before');
        }

        if (!Middleware::hasAttribute($request, ClientIp::KEY)) {
            throw new RuntimeException('Csrf middleware needs ClientIp executed before');
        }

        if ($this->storage === null) {
            if (session_status() !== PHP_SESSION_ACTIVE) {
                throw new RuntimeException('Csrf middleware needs an active php session or a storage defined');
            }

            if (!isset($_SESSION[$this->sessionIndex])) {
                $_SESSION[$this->sessionIndex] = [];
            }

            $this->storage = &$_SESSION[$this->sessionIndex];
        }

        if (FormatNegotiator::getFormat($request) !== 'html') {
            return $next($request, $response);
        }

        if (Utils\Helpers::isPost($request) && !$this->validateRequest($request)) {
            return $response->withStatus(403);
        }

        $response = $next($request, $response);

        return $this->insertIntoPostForms($response, function ($match) use ($request) {
            preg_match('/action=["\']?([^"\'\s]+)["\']?/i', $match[0], $matches);

            $action = empty($matches[1]) ? $request->getUri()->getPath() : $matches[1];

            return $match[0].$this->generateTokens($request, $action);
        });
    }

    /**
     * Generate and retrieve the tokens.
     * 
     * @param ServerRequestInterface $request
     * @param string                 $lockTo
     *
     * @return array
     */
    private function generateTokens(ServerRequestInterface $request, $lockTo)
    {
        $index = self::encode(random_bytes(18));

        $token = self::encode(random_bytes(32));


        $this->storage[$index] = [
            'created' => intval(date('YmdHis')),
            'uri' => $request->getUri()->getPath(),
            'token' => $token,
            'lockTo' => $lockTo,
        ];

        $this->recycleTokens();

        $token = self::encode(hash_hmac('sha256', ClientIp::getIp($request), base64_decode($token), true));

        return '<input type="hidden" name="'.$this->formIndex.'" value="'.htmlentities($index, ENT_QUOTES, 'UTF-8').'">'
               .'<input type="hidden" name="'.$this->formToken.'" value="'.htmlentities($token, ENT_QUOTES, 'UTF-8').'">';
    }

    /**
     * Validate the request.
     * 
     * @param ServerRequestInterface $request
     *
     * @return bool
     */
    private function validateRequest(ServerRequestInterface $request)
    {
        $data = $request->getParsedBody();

        if (!isset($data[$this->formIndex]) || !isset($data[$this->formToken])) {
            return false;
        }

        $index = $data[$this->formIndex];
        $token = $data[$this->formToken];

        if (!isset($this->storage[$index])) {
            return false;
        }

        $stored = $this->storage[$index];
        unset($this->storage[$index]);

        $lockTo = $request->getUri()->getPath();

        if (!Utils\Helpers::hashEquals($lockTo, $stored['lockTo'])) {
            return false;
        }

        $expected = self::encode(hash_hmac('sha256', ClientIp::getIp($request), base64_decode($stored['token']), true));

        return Utils\Helpers::hashEquals($token, $expected);
    }

    /**
     * Enforce an upper limit on the number of tokens stored in session state
     * by removing the oldest tokens first.
     */
    private function recycleTokens()
    {
        if (!$this->maxTokens || count($this->storage) <= $this->maxTokens) {
            return;
        }

        uasort($this->storage, function ($a, $b) {
            return $a['created'] - $b['created'];
        });

        while (count($this->storage) > $this->maxTokens) {
            array_shift($this->storage);
        }
    }

    /**
     * Encode string with base64, but strip padding.
     * PHP base64_decode does not croak on that.
     *
     * @param string $value
     *
     * @return string
     */
    private static function encode($value)
    {
        return rtrim(base64_encode($value), '=');
    }
}


1			<?php
2
3			namespace Psr7Middlewares\Middleware;
4
5			use Psr7Middlewares\Middleware;
6			use Psr7Middlewares\Utils;
7			use Psr\Http\Message\ServerRequestInterface;
8			use Psr\Http\Message\ResponseInterface;
9			use RuntimeException;
10			use ArrayAccess;
11
12			/**
13			* Middleware for CSRF protection
14			* Code inspired from https://github.com/paragonie/anti-csrf.
15			*/
16			class Csrf
17			{
18			use Utils\FormTrait;
19
20			/**
21			* @var int Max number of CSRF tokens
22			*/
23			private $maxTokens = 100;
24
25			/**
26			* @var string field name with the CSRF index
27			*/
28			private $formIndex = '_CSRF_INDEX';
29
30			/**
31			* @var string field name with the CSRF token
32			*/
33			private $formToken = '_CSRF_TOKEN';
34
35			/*
36			* @var array\|ArrayAccess CSRF storage
37			*/
38			private $storage;
39
40			/**
41			* @var string Index used in the storage
42			*/
43			private $sessionIndex = 'CSRF';
44
45			/**
46			* Set the storage of the CSRF
47			*
48			* @param array\|ArrayAccess\|null $storage
49			*/
50			public function __construct(&$storage = null)
51			{
52			if (is_array($storage)) {
53			$this->storage = &$storage;
54			} elseif ($storage instanceof ArrayAccess) {
55			$this->storage = $storage;
56			} elseif ($storage !== null) {
57			throw new InvalidArgumentException('The storage argument must be an array, ArrayAccess or null');
58			}
59			}
60
61			/**
62			* Execute the middleware.
63			*
64			* @param ServerRequestInterface $request
65			* @param ResponseInterface $response
66			* @param callable $next
67			*
68			* @return ResponseInterface
69			*/
70			public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next)
			0 ignored issues – show Coding Style introduced 2016-01-13 08:31 UTC by Report Bug Copy Issue Report `__invoke` uses the super-global variable `$_SESSION` which is generally not recommended. Instead of super-globals, we recommend to explicitly inject the dependencies of your class. This makes your code less dependent on global state and it becomes generally more testable: // Bad class Router { public function generate($path) { return $_SERVER['HOST'].$path; } } // Better class Router { private $host; public function __construct($host) { $this->host = $host; } public function generate($path) { return $this->host.$path; } } class Controller { public function myAction(Request $request) { // Instead of $page = isset($_GET['page']) ? intval($_GET['page']) : 1; // Better (assuming you use the Symfony2 request) $page = $request->query->get('page', 1); } } Loading history...
71			{
72			if (!Middleware::hasAttribute($request, FormatNegotiator::KEY)) {
73			throw new RuntimeException('Csrf middleware needs FormatNegotiator executed before');
74			}
75
76			if (!Middleware::hasAttribute($request, ClientIp::KEY)) {
77			throw new RuntimeException('Csrf middleware needs ClientIp executed before');
78			}
79
80			if ($this->storage === null) {
81			if (session_status() !== PHP_SESSION_ACTIVE) {
82			throw new RuntimeException('Csrf middleware needs an active php session or a storage defined');
83			}
84
85			if (!isset($_SESSION[$this->sessionIndex])) {
86			$_SESSION[$this->sessionIndex] = [];
87			}
88
89			$this->storage = &$_SESSION[$this->sessionIndex];
90			}
91
92			if (FormatNegotiator::getFormat($request) !== 'html') {
93			return $next($request, $response);
94			}
95
96			if (Utils\Helpers::isPost($request) && !$this->validateRequest($request)) {
97			return $response->withStatus(403);
98			}
99
100			$response = $next($request, $response);
101
102			return $this->insertIntoPostForms($response, function ($match) use ($request) {
103			preg_match('/action=["\']?([^"\'\s]+)["\']?/i', $match[0], $matches);
104
105			$action = empty($matches[1]) ? $request->getUri()->getPath() : $matches[1];
106
107			return $match[0].$this->generateTokens($request, $action);
108			});
109			}
110
111			/**
112			* Generate and retrieve the tokens.
113			*
114			* @param ServerRequestInterface $request
115			* @param string $lockTo
116			*
117			* @return array
118			*/
119			private function generateTokens(ServerRequestInterface $request, $lockTo)
120			{
121			$index = self::encode(random_bytes(18));
			0 ignored issues – show Unused Code introduced 2016-01-12 12:47 UTC by Report Bug Copy Issue Report The call to `random_bytes()` has too many arguments starting with `18`. This check compares calls to functions or methods with their respective definitions. If the call has more arguments than are defined, it raises an issue. If a function is defined several times with a different number of parameters, the check may pick up the wrong definition and report false positives. One codebase where this has been known to happen is Wordpress. In this case you can add the `@ignore` PhpDoc annotation to the duplicate definition and it will be ignored. Loading history...
122			$token = self::encode(random_bytes(32));
			0 ignored issues – show Unused Code introduced 2016-01-12 12:47 UTC by Report Bug Copy Issue Report The call to `random_bytes()` has too many arguments starting with `32`. This check compares calls to functions or methods with their respective definitions. If the call has more arguments than are defined, it raises an issue. If a function is defined several times with a different number of parameters, the check may pick up the wrong definition and report false positives. One codebase where this has been known to happen is Wordpress. In this case you can add the `@ignore` PhpDoc annotation to the duplicate definition and it will be ignored. Loading history...
123
124			$this->storage[$index] = [
125			'created' => intval(date('YmdHis')),
126			'uri' => $request->getUri()->getPath(),
127			'token' => $token,
128			'lockTo' => $lockTo,
129			];
130
131			$this->recycleTokens();
132
133			$token = self::encode(hash_hmac('sha256', ClientIp::getIp($request), base64_decode($token), true));
134
135			return '<input type="hidden" name="'.$this->formIndex.'" value="'.htmlentities($index, ENT_QUOTES, 'UTF-8').'">'
136			.'<input type="hidden" name="'.$this->formToken.'" value="'.htmlentities($token, ENT_QUOTES, 'UTF-8').'">';
137			}
138
139			/**
140			* Validate the request.
141			*
142			* @param ServerRequestInterface $request
143			*
144			* @return bool
145			*/
146			private function validateRequest(ServerRequestInterface $request)
147			{
148			$data = $request->getParsedBody();
149
150			if (!isset($data[$this->formIndex]) \|\| !isset($data[$this->formToken])) {
151			return false;
152			}
153
154			$index = $data[$this->formIndex];
155			$token = $data[$this->formToken];
156
157			if (!isset($this->storage[$index])) {
158			return false;
159			}
160
161			$stored = $this->storage[$index];
162			unset($this->storage[$index]);
163
164			$lockTo = $request->getUri()->getPath();
165
166			if (!Utils\Helpers::hashEquals($lockTo, $stored['lockTo'])) {
167			return false;
168			}
169
170			$expected = self::encode(hash_hmac('sha256', ClientIp::getIp($request), base64_decode($stored['token']), true));
171
172			return Utils\Helpers::hashEquals($token, $expected);
173			}
174
175			/**
176			* Enforce an upper limit on the number of tokens stored in session state
177			* by removing the oldest tokens first.
178			*/
179			private function recycleTokens()
180			{
181			if (!$this->maxTokens \|\| count($this->storage) <= $this->maxTokens) {
182			return;
183			}
184
185			uasort($this->storage, function ($a, $b) {
186			return $a['created'] - $b['created'];
187			});
188
189			while (count($this->storage) > $this->maxTokens) {
190			array_shift($this->storage);
191			}
192			}
193
194			/**
195			* Encode string with base64, but strip padding.
196			* PHP base64_decode does not croak on that.
197			*
198			* @param string $value
199			*
200			* @return string
201			*/
202			private static function encode($value)
203			{
204			return rtrim(base64_encode($value), '=');
205			}
206			}
207

oscarotero / psr7-middlewares

Push — master ( 345022...5c5fe2 )

Csrf::__construct() A

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