Limiter::_generate_hash() - Code Metrics - Inspection of "Filters should work properly after updating the MA..." - DakuTree/manga-tracker - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 23153f...eb881d )

by Angus

created 2017-08-29 16:56 UTC

Limiter::_generate_hash() A

↳ Parent: Limiter

Complexity

Conditions	1
Paths	1

Size

Total Lines	3
Code Lines	2

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	1
eloc	2
nc	1
nop	0
dl	0
loc	3
rs	10
c	0
b	0
f	0

<?php

/**
 * CodeIgniter limiter
 *
 * @license     MIT License
 * @package     Limiter
 * @author      Mechazawa
 * @version     1.0.0
 */


class Limiter {

    /** @type CI_Controller */
    protected $CI;
    protected $table      = 'rate_limit';
    protected $base_limit = 0; // infinite
    protected $whitelist  = array('127.0.0.1');
    protected $header_show        = TRUE;
    protected $checksum_algorithm = 'md4';
    protected $header_prefix      = 'X-RateLimit-';
    protected $flush_on_abort     = FALSE;

    protected $user_data = array();
    protected $user_hash = FALSE;

    private $_truncated  = FALSE;
    private $_info_cache = array();

    private $_sql_truncate  = 'DELETE FROM `RATE_TABLE` WHERE `start` < (NOW() - INTERVAL 1 HOUR)';
    private $_sql_info      = 'SELECT `count`, `start`, (`start` + INTERVAL (1 - TIMESTAMPDIFF(HOUR, UTC_TIMESTAMP(), NOW())) HOUR) \'reset_epoch\' FROM `RATE_TABLE` WHERE `client` = ? AND `target` = ?';
    private $_sql_update    = 'INSERT INTO `RATE_TABLE` (`client`, `target`) VALUES (?, ?) ON DUPLICATE KEY UPDATE `count` = `count` + 1';
    private $_config_fields = array(
        'table', 'base_limit', 'checksum_algorithm',
        'header', 'header_prefix', 'flush_on_abort'
    );

    public function __construct($config = array()) {
        $this->CI = &get_instance();

        if(!is_array($config)) {
            $config = array();
        }

        foreach($this->_config_fields as $field) {
            if(array_key_exists($field, $config)) {
                $this->{$field} = $config[$field];
            }
        }

        $sql = array('truncate', 'info', 'update');
        foreach($sql as $s) {
            $this->{"_sql_$s"} = str_replace('RATE_TABLE', $this->table, $this->{"_sql_$s"});
        }

        $this->add_user_data($this->CI->input->ip_address());

        log_message('debug', 'Limiter Class Initialized');
    }

    /**
     * Rate limits the amount of requests that can be sent by a client.
     *
     * @param string $target
     * @param int $req_per_hour Overrides base_limit setting if set
     * @param bool $flush_on_abort Overrides flush_on_abort setting if set
     * @param bool $show_header Overrides header_show setting if set
     * @return bool Should request be aborted
     */
    public function limit($target = '_global', $req_per_hour = null, $flush_on_abort = null, $show_header = null) {
        $req_per_hour   = $req_per_hour !== null ? $req_per_hour : $this->base_limit;
        $flush_on_abort = $flush_on_abort !== null ? $flush_on_abort : $this->flush_on_abort;
        $show_header    = $show_header !== null ? $show_header : $this->header_show;

        $truncated = $this->_truncate();
        if(!$truncated) {
            log_message('DEBUG', 'WARN: Could not truncate rate limit table');
        }

        if($this->is_whitelisted()) {
            $req_per_hour = 0;
        }

        $abort = FALSE;
        if($req_per_hour > 0) {
            $info = $this->get_limit_info($target);

            if($info === FALSE) {
                $info              = new stdClass();
                $info->count       = 0;
                $info->reset_epoch = gmdate('d M Y H:i:s', time() + (60 * 60));
                $info->start       = date('d M Y H:i:s');
            }

            if($req_per_hour - $info->count > 0) {
                $data = array('client' => $this->get_hash(), 'target' => $target);
                $this->CI->db->query($this->_sql_update, $data);
                $info->count++;
            } else {
                $abort = TRUE;
            }

            if($show_header === TRUE) {
                $headers = array(
                    'Limit' => $req_per_hour,
                    'Remaining' => $req_per_hour - $info->count,
                    'Reset' => strtotime($info->reset_epoch),
                );

                foreach(array_keys($headers) as $h) {
                    $this->CI->output->set_header("$this->header_prefix$h: $headers[$h]");
                }
            }

            $this->_info_cache[$target] = $info;


            if($abort) {
                $retry_seconds = strtotime($info->reset_epoch) - strtotime(gmdate('d M Y H:i:s'));
                $this->CI->output->set_header("Retry-After: $retry_seconds");
                $this->CI->output->set_status_header(503, 'Rate limit reached');

                if($flush_on_abort) {
                    $this->CI->output->_display();
                    exit;

                }
            }
        }

        return $abort;
    }

    /**
     * Forget the client ever visited $target.
     *
     * @param string $target
     */
    public function reset_rate($target = '_global') {
        $this->CI->db->delete($this->table, array(
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
            'client' => $this->get_hash(),
            'target' => $target
        ));
    }

    /**
     * Forgets all rate limits attached to the client.
     */
    public function forget_client() {
        $this->CI->db->delete($this->table, array('client' => $this->get_hash()));
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
    }

    /**
     * Used to obtain the client hash.
     *
     * Returns false if hash generation failed
     * @return string
     */
    public function get_hash() {
        if($this->user_hash === FALSE) {
            $this->user_hash = $this->_generate_hash();
$answer = 42;

$correct = false;

$correct = (bool) $answer;
        }
        return $this->user_hash;
    }

    /**
     * Adds entropy to the client hash. Make
     * sure that this is some sort of static
     * data such as a username/id.
     *
     * @param string $data Any seeding data
     */
    public function add_user_data($data) {
        array_push($this->user_data, (string) $data);

        if(count($this->_info_cache) !== 0) {
            log_message('DEBUG', 'WARN: Emptying info cache due to user data changing');
            $this->_info_cache = array(); // Empty cache
        }

        if($this->user_hash !== FALSE) {
            log_message('DEBUG', 'WARN: Adding user data after hash was generated');
            $this->user_hash = $this->_generate_hash();
$answer = 42;

$correct = false;

$correct = (bool) $answer;
        }
    }

    /**
     * Get target rate info
     *
     * @param string $target
     * @return stdClass|false Info object, returns false if no info is present
     */
    public function get_limit_info($target = '_global') {
        if(!array_key_exists($target, $this->_info_cache)) {
            $data = array('client' => $this->get_hash(), 'target' => $target);
            $info = $this->CI->db->query($this->_sql_info, $data)->row();

            $this->_info_cache[$target] = $info;
        } else {
            $info = $this->_info_cache[$target];
        }

        $valid_data = isset($info->count);
        return $valid_data ? $info : FALSE;
    }

    /**
     * @param $target
     * @return integer Amount of attempts
     */
    public function get_attempts($target) {
        return $this->get_limit_info($target)->count;
    }

    /**
     * @param null $ip If null current IP
     * @return bool Is whitelisted
     */
    public function is_whitelisted($ip = null) {
        $ip = $ip ?:  $this->CI->input->ip_address();
        return in_array($ip, $this->whitelist);
    }

    private function _truncate() {
        if(!$this->_truncated) {
            $this->_truncated = $this->CI->db->query($this->_sql_truncate);
        }
        return $this->_truncated;
    }

    private function _generate_hash() {
        return hash($this->checksum_algorithm, join('%', $this->user_data));
    }
}


1			<?php
2
3			/**
4			* CodeIgniter limiter
5			*
6			* @license MIT License
7			* @package Limiter
8			* @author Mechazawa
9			* @version 1.0.0
10			*/
11
12
13			class Limiter {
14
15			/** @type CI_Controller */
16			protected $CI;
17			protected $table = 'rate_limit';
18			protected $base_limit = 0; // infinite
19			protected $whitelist = array('127.0.0.1');
20			protected $header_show = TRUE;
21			protected $checksum_algorithm = 'md4';
22			protected $header_prefix = 'X-RateLimit-';
23			protected $flush_on_abort = FALSE;
24
25			protected $user_data = array();
26			protected $user_hash = FALSE;
27
28			private $_truncated = FALSE;
29			private $_info_cache = array();
30
31			private $_sql_truncate = 'DELETE FROM `RATE_TABLE` WHERE `start` < (NOW() - INTERVAL 1 HOUR)';
32			private $_sql_info = 'SELECT `count`, `start`, (`start` + INTERVAL (1 - TIMESTAMPDIFF(HOUR, UTC_TIMESTAMP(), NOW())) HOUR) \'reset_epoch\' FROM `RATE_TABLE` WHERE `client` = ? AND `target` = ?';
33			private $_sql_update = 'INSERT INTO `RATE_TABLE` (`client`, `target`) VALUES (?, ?) ON DUPLICATE KEY UPDATE `count` = `count` + 1';
34			private $_config_fields = array(
35			'table', 'base_limit', 'checksum_algorithm',
36			'header', 'header_prefix', 'flush_on_abort'
37			);
38
39			public function __construct($config = array()) {
40			$this->CI = &get_instance();
41
42			if(!is_array($config)) {
43			$config = array();
44			}
45
46			foreach($this->_config_fields as $field) {
47			if(array_key_exists($field, $config)) {
48			$this->{$field} = $config[$field];
49			}
50			}
51
52			$sql = array('truncate', 'info', 'update');
53			foreach($sql as $s) {
54			$this->{"_sql_$s"} = str_replace('RATE_TABLE', $this->table, $this->{"_sql_$s"});
55			}
56
57			$this->add_user_data($this->CI->input->ip_address());
58
59			log_message('debug', 'Limiter Class Initialized');
60			}
61
62			/**
63			* Rate limits the amount of requests that can be sent by a client.
64			*
65			* @param string $target
66			* @param int $req_per_hour Overrides base_limit setting if set
67			* @param bool $flush_on_abort Overrides flush_on_abort setting if set
68			* @param bool $show_header Overrides header_show setting if set
69			* @return bool Should request be aborted
70			*/
71			public function limit($target = '_global', $req_per_hour = null, $flush_on_abort = null, $show_header = null) {
72			$req_per_hour = $req_per_hour !== null ? $req_per_hour : $this->base_limit;
73			$flush_on_abort = $flush_on_abort !== null ? $flush_on_abort : $this->flush_on_abort;
74			$show_header = $show_header !== null ? $show_header : $this->header_show;
75
76			$truncated = $this->_truncate();
77			if(!$truncated) {
78			log_message('DEBUG', 'WARN: Could not truncate rate limit table');
79			}
80
81			if($this->is_whitelisted()) {
82			$req_per_hour = 0;
83			}
84
85			$abort = FALSE;
86			if($req_per_hour > 0) {
87			$info = $this->get_limit_info($target);
88
89			if($info === FALSE) {
90			$info = new stdClass();
91			$info->count = 0;
92			$info->reset_epoch = gmdate('d M Y H:i:s', time() + (60 * 60));
93			$info->start = date('d M Y H:i:s');
94			}
95
96			if($req_per_hour - $info->count > 0) {
97			$data = array('client' => $this->get_hash(), 'target' => $target);
98			$this->CI->db->query($this->_sql_update, $data);
99			$info->count++;
100			} else {
101			$abort = TRUE;
102			}
103
104			if($show_header === TRUE) {
105			$headers = array(
106			'Limit' => $req_per_hour,
107			'Remaining' => $req_per_hour - $info->count,
108			'Reset' => strtotime($info->reset_epoch),
109			);
110
111			foreach(array_keys($headers) as $h) {
112			$this->CI->output->set_header("$this->header_prefix$h: $headers[$h]");
113			}
114			}
115
116			$this->_info_cache[$target] = $info;
117
118
119			if($abort) {
120			$retry_seconds = strtotime($info->reset_epoch) - strtotime(gmdate('d M Y H:i:s'));
121			$this->CI->output->set_header("Retry-After: $retry_seconds");
122			$this->CI->output->set_status_header(503, 'Rate limit reached');
123
124			if($flush_on_abort) {
125			$this->CI->output->_display();
126			exit;
			0 ignored issues – show Coding Style Compatibility introduced 2017-08-29 16:59 UTC by Report Bug Copy Issue Report The method `limit()` contains an exit expression. An exit expression should only be used in rare cases. For example, if you write a short command line script. In most cases however, using an `exit` expression makes the code untestable and often causes incompatibilities with other libraries. Thus, unless you are absolutely sure it is required here, we recommend to refactor your code to avoid its usage. Loading history...
127			}
128			}
129			}
130
131			return $abort;
132			}
133
134			/**
135			* Forget the client ever visited $target.
136			*
137			* @param string $target
138			*/
139			public function reset_rate($target = '_global') {
140			$this->CI->db->delete($this->table, array(
			0 ignored issues – show Documentation introduced 2017-08-29 16:59 UTC by Report Bug Copy Issue Report `array('client' => $this-...), 'target' => $target)` is of type `array<string,string\|bool...an","target":"string"}>`, but the function expects a `string`. It seems like the type of the argument is not accepted by the function/method which you are calling. In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug. We suggest to add an explicit type cast like in the following example: function acceptsInteger($int) { } $x = '123'; // string "123" // Instead of acceptsInteger($x); // we recommend to use acceptsInteger((integer) $x); Loading history...
141			'client' => $this->get_hash(),
142			'target' => $target
143			));
144			}
145
146			/**
147			* Forgets all rate limits attached to the client.
148			*/
149			public function forget_client() {
150			$this->CI->db->delete($this->table, array('client' => $this->get_hash()));
			0 ignored issues – show Documentation introduced 2017-08-29 16:59 UTC by Report Bug Copy Issue Report `array('client' => $this->get_hash())` is of type `array<string,string\|bool...ent":"string\|boolean"}>`, but the function expects a `string`. It seems like the type of the argument is not accepted by the function/method which you are calling. In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug. We suggest to add an explicit type cast like in the following example: function acceptsInteger($int) { } $x = '123'; // string "123" // Instead of acceptsInteger($x); // we recommend to use acceptsInteger((integer) $x); Loading history...
151			}
152
153			/**
154			* Used to obtain the client hash.
155			*
156			* Returns false if hash generation failed
157			* @return string
158			*/
159			public function get_hash() {
160			if($this->user_hash === FALSE) {
161			$this->user_hash = $this->_generate_hash();
			0 ignored issues – show Documentation Bug introduced 2017-08-29 16:59 UTC by Report Bug Copy Issue Report The property `$user_hash` was declared of type `boolean`, but `$this->_generate_hash()` is of type `string`. Maybe add a type cast? This check looks for assignments to scalar types that may be of the wrong type. To ensure the code behaves as expected, it may be a good idea to add an explicit type cast. $answer = 42; $correct = false; $correct = (bool) $answer; Loading history...
162			}
163			return $this->user_hash;
164			}
165
166			/**
167			* Adds entropy to the client hash. Make
168			* sure that this is some sort of static
169			* data such as a username/id.
170			*
171			* @param string $data Any seeding data
172			*/
173			public function add_user_data($data) {
174			array_push($this->user_data, (string) $data);
175
176			if(count($this->_info_cache) !== 0) {
177			log_message('DEBUG', 'WARN: Emptying info cache due to user data changing');
178			$this->_info_cache = array(); // Empty cache
179			}
180
181			if($this->user_hash !== FALSE) {
182			log_message('DEBUG', 'WARN: Adding user data after hash was generated');
183			$this->user_hash = $this->_generate_hash();
			0 ignored issues – show Documentation Bug introduced 2017-08-29 16:59 UTC by Report Bug Copy Issue Report The property `$user_hash` was declared of type `boolean`, but `$this->_generate_hash()` is of type `string`. Maybe add a type cast? This check looks for assignments to scalar types that may be of the wrong type. To ensure the code behaves as expected, it may be a good idea to add an explicit type cast. $answer = 42; $correct = false; $correct = (bool) $answer; Loading history...
184			}
185			}
186
187			/**
188			* Get target rate info
189			*
190			* @param string $target
191			* @return stdClass\|false Info object, returns false if no info is present
192			*/
193			public function get_limit_info($target = '_global') {
194			if(!array_key_exists($target, $this->_info_cache)) {
195			$data = array('client' => $this->get_hash(), 'target' => $target);
196			$info = $this->CI->db->query($this->_sql_info, $data)->row();
197
198			$this->_info_cache[$target] = $info;
199			} else {
200			$info = $this->_info_cache[$target];
201			}
202
203			$valid_data = isset($info->count);
204			return $valid_data ? $info : FALSE;
205			}
206
207			/**
208			* @param $target
209			* @return integer Amount of attempts
210			*/
211			public function get_attempts($target) {
212			return $this->get_limit_info($target)->count;
213			}
214
215			/**
216			* @param null $ip If null current IP
217			* @return bool Is whitelisted
218			*/
219			public function is_whitelisted($ip = null) {
220			$ip = $ip ?: $this->CI->input->ip_address();
221			return in_array($ip, $this->whitelist);
222			}
223
224			private function _truncate() {
225			if(!$this->_truncated) {
226			$this->_truncated = $this->CI->db->query($this->_sql_truncate);
227			}
228			return $this->_truncated;
229			}
230
231			private function _generate_hash() {
232			return hash($this->checksum_algorithm, join('%', $this->user_data));
233			}
234			}
235

DakuTree / manga-tracker

Push — master ( 23153f...eb881d )

Limiter::_generate_hash() A

Complexity

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Duplication

Importance

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