CsrfGuard::generateToken() - Code Metrics - Inspection of "Merge pull request #4 from linna/v1.1.0" - linna/csrf-guard - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Push — master ( 84ad64...95abf0 )

by Sebastian

created 2017-08-20 09:26 UTC

CsrfGuard::generateToken() A

↳ Parent: CsrfGuard

Complexity

Conditions	1
Paths	1

Size

Total Lines	7
Code Lines	4

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	4
CRAP Score	1

Importance

Changes

Metric	Value
dl	0
loc	7
ccs	4
cts	4
cp	1
rs	9.4285
c	0
b	0
f	0
cc	1
eloc	4
nc	1
nop	0
crap	1

<?php

/**
 * Linna Cross-site Request Forgery Guard
 *
 * @author Sebastian Rapetti <[email protected]>
 * @copyright (c) 2017, Sebastian Rapetti
 * @license http://opensource.org/licenses/MIT MIT License
 */
declare(strict_types=1);

namespace Linna;

use RuntimeException;

/**
 * Cross-site Request Forgery Guard
 */
class CsrfGuard
{
    /**
     * @var array Php session data from superglobal.
     */
    private $session;

    /**
     * @var int Max number of tokens stored in session.
     */
    private $maxStorage;

    /**
     * @var int Rapresent the lenght of the token in bytes.
     */
    private $tokenStrength;
    
    /**
     * Constructor.
     *
     * @param int $maxStorage    Max number of tokens stored in session, work as
     *                           FIFO data structure, when maximun capacity is
     *                           reached, oldest token be dequeued from storage.
     * @param int $tokenStrength Rapresent the lenght of the token in bytes.
     */
    public function __construct(int $maxStorage, int $tokenStrength)
    {
        if (session_status() === 1) {
            throw new RuntimeException(__CLASS__.': Session must be started before create '.__CLASS__.' instance.');
        }
        
        //if csrf array doesn't exist inside session, initialize it.
        //for code shortness: Null coalescing operator
        //http://php.net/manual/en/migration70.new-features.php
        $_SESSION['CSRF'] = $_SESSION['CSRF'] ?? [];

        $this->session = &$_SESSION;
        $this->maxStorage = $maxStorage;
        $this->tokenStrength = $tokenStrength;
    }

    /**
     * Limit number of token stored in session.
     */
    private function dequeue(array &$array)
    {
        $size = count($array);
        
        while ($size > $this->maxStorage) {
            array_shift($array);
            $size--;
        }
    }

    /**
     * Return csrf token as array.
     *
     * @return array
     */
    public function getToken() : array
    {
        $token = $this->generateToken();

        $name = $token['name'];

        $this->session['CSRF'][$name] = $token;

        //storage cleaning!
        //warning!! if you get in a page more token of maximun storage,
        //will there a leak of token, the firsts generated
        //in future I think throw and exception.
        $this->dequeue($this->session['CSRF']);

        return $token;
    }

    /**
     * Return timed csrf token as array.
     *
     * @param int $ttl Time to live for the token.
     *
     * @return array
     */
    public function getTimedToken(int $ttl) : array
    {
        $token = $this->generateToken();
        $token['time'] = time() + $ttl;
        
        $name = $token['name'];

        $this->session['CSRF'][$name] = $token;

        $this->dequeue($this->session['CSRF']);

        return $token;
    }
    
    /**
     * Generate a random token.
     *
     * @return array
     */
    private function generateToken() : array
    {
        $name = 'csrf_'.bin2hex(random_bytes(8));
        $value = bin2hex(random_bytes($this->tokenStrength));
        
        return ['name' => $name, 'value' => $value];
    }
    
    /**
     * Return csrf token as hidden input form.
     *
     * @return string
     *
     * @deprecated since version 1.1.0
     */
    public function getHiddenInput() : string
    {
        $token = $this->getToken();

        return '<input type="hidden" name="'.$token['name'].'" value="'.$token['value'].'" />';
    }

    /**
     * Validate a csrf token.
     *
     * @param array $requestData From request or from superglobal variables $_POST,
     *                           $_GET, $_REQUEST and $_COOKIE.
     *
     * @return bool
     */
    public function validate(array $requestData) : bool
    {
        //apply matchToken method elements of passed data,
        //using this instead of forach for code shortness.
        $array = array_filter($requestData, array($this, 'matchToken'), ARRAY_FILTER_USE_BOTH);

        return (bool) count($array);
    }
    
    /**
     * Tests for valid token.
     *
     * @param string $value
     * @param string $key
     *
     * @return bool
     */
    private function matchToken(string $value, string $key) : bool
    {
        $tokens = $this->session['CSRF'];

        //check if token exist
        if (!isset($tokens[$key])) {
            return false;
        }

        //check if token is valid
        if (!hash_equals($tokens[$key]['value'], $value)) {
            return false;
        }

        //check if token is expired if timed
        if (isset($tokens[$key]['time']) && $tokens[$key]['time'] < time()) {
            return false;
        }
 
        return true;
    }
}


1		<?php
2
3		/**
4		* Linna Cross-site Request Forgery Guard
5		*
6		* @author Sebastian Rapetti <[email protected]>
7		* @copyright (c) 2017, Sebastian Rapetti
8		* @license http://opensource.org/licenses/MIT MIT License
9		*/
10		declare(strict_types=1);
11
12		namespace Linna;
13
14		use RuntimeException;
15
16		/**
17		* Cross-site Request Forgery Guard
18		*/
19		class CsrfGuard
20		{
21		/**
22		* @var array Php session data from superglobal.
23		*/
24		private $session;
25
26		/**
27		* @var int Max number of tokens stored in session.
28		*/
29		private $maxStorage;
30
31		/**
32		* @var int Rapresent the lenght of the token in bytes.
33		*/
34		private $tokenStrength;
35
36		/**
37		* Constructor.
38		*
39		* @param int $maxStorage Max number of tokens stored in session, work as
40		* FIFO data structure, when maximun capacity is
41		* reached, oldest token be dequeued from storage.
42		* @param int $tokenStrength Rapresent the lenght of the token in bytes.
43		*/
44	20	public function __construct(int $maxStorage, int $tokenStrength)
45		{
46	20	if (session_status() === 1) {
47	1	throw new RuntimeException(__CLASS__.': Session must be started before create '.__CLASS__.' instance.');
48		}
49
50		//if csrf array doesn't exist inside session, initialize it.
51		//for code shortness: Null coalescing operator
52		//http://php.net/manual/en/migration70.new-features.php
53	19	$_SESSION['CSRF'] = $_SESSION['CSRF'] ?? [];
54
55	19	$this->session = &$_SESSION;
56	19	$this->maxStorage = $maxStorage;
57	19	$this->tokenStrength = $tokenStrength;
58	19	}
59
60		/**
61		* Limit number of token stored in session.
62		*/
63	18	private function dequeue(array &$array)
64		{
65	18	$size = count($array);
66
67	18	while ($size > $this->maxStorage) {
68	14	array_shift($array);
69	14	$size--;
70		}
71	18	}
72
73		/**
74		* Return csrf token as array.
75		*
76		* @return array
77		*/
78	17	public function getToken() : array
79		{
80	17	$token = $this->generateToken();
81
82	17	$name = $token['name'];
83
84	17	$this->session['CSRF'][$name] = $token;
85
86		//storage cleaning!
87		//warning!! if you get in a page more token of maximun storage,
88		//will there a leak of token, the firsts generated
89		//in future I think throw and exception.
90	17	$this->dequeue($this->session['CSRF']);
91
92	17	return $token;
93		}
94
95		/**
96		* Return timed csrf token as array.
97		*
98		* @param int $ttl Time to live for the token.
99		*
100		* @return array
101		*/
102	1	public function getTimedToken(int $ttl) : array
103		{
104	1	$token = $this->generateToken();
105	1	$token['time'] = time() + $ttl;
106
107	1	$name = $token['name'];
108
109	1	$this->session['CSRF'][$name] = $token;
110
111	1	$this->dequeue($this->session['CSRF']);
112
113	1	return $token;
114		}
115
116		/**
117		* Generate a random token.
118		*
119		* @return array
120		*/
121	18	private function generateToken() : array
122		{
123	18	$name = 'csrf_'.bin2hex(random_bytes(8));
124	18	$value = bin2hex(random_bytes($this->tokenStrength));
125
126	18	return ['name' => $name, 'value' => $value];
127		}
128
129		/**
130		* Return csrf token as hidden input form.
131		*
132		* @return string
133		*
134		* @deprecated since version 1.1.0
135		*/
136	1	public function getHiddenInput() : string
137		{
138	1	$token = $this->getToken();
139
140	1	return '<input type="hidden" name="'.$token['name'].'" value="'.$token['value'].'" />';
141		}
142
143		/**
144		* Validate a csrf token.
145		*
146		* @param array $requestData From request or from superglobal variables $_POST,
147		* $_GET, $_REQUEST and $_COOKIE.
148		*
149		* @return bool
150		*/
151	1	public function validate(array $requestData) : bool
152		{
153		//apply matchToken method elements of passed data,
154		//using this instead of forach for code shortness.
155	1	$array = array_filter($requestData, array($this, 'matchToken'), ARRAY_FILTER_USE_BOTH);
156
157	1	return (bool) count($array);
158		}
159
160		/**
161		* Tests for valid token.
162		*
163		* @param string $value
164		* @param string $key
165		*
166		* @return bool
167		*/
168	1	private function matchToken(string $value, string $key) : bool
169		{
170	1	$tokens = $this->session['CSRF'];
171
172		//check if token exist
173	1	if (!isset($tokens[$key])) {
174	1	return false;
175		}
176
177		//check if token is valid
178	1	if (!hash_equals($tokens[$key]['value'], $value)) {
179	1	return false;
180		}
181
182		//check if token is expired if timed
183	1	if (isset($tokens[$key]['time']) && $tokens[$key]['time'] < time()) {
184		return false;
185		}
186
187	1	return true;
188		}
189		}
190

linna / csrf-guard

Push — master ( 84ad64...95abf0 )

CsrfGuard::generateToken() A

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