1<?php
2/**
3 * CodeIgniter
4 *
5 * An open source application development framework for PHP
6 *
7 * This content is released under the MIT License (MIT)
8 *
9 * Copyright (c) 2014 - 2019, British Columbia Institute of Technology
10 *
11 * Permission is hereby granted, free of charge, to any person obtaining a copy
12 * of this software and associated documentation files (the "Software"), to deal
13 * in the Software without restriction, including without limitation the rights
14 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
15 * copies of the Software, and to permit persons to whom the Software is
16 * furnished to do so, subject to the following conditions:
17 *
18 * The above copyright notice and this permission notice shall be included in
19 * all copies or substantial portions of the Software.
20 *
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
22 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
24 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
25 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
26 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
27 * THE SOFTWARE.
28 *
29 * @package	CodeIgniter
30 * @author	EllisLab Dev Team
31 * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
32 * @copyright	Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
33 * @license	https://opensource.org/licenses/MIT	MIT License
34 * @link	https://codeigniter.com
35 * @since	Version 1.0.0
36 * @filesource
37 */
38defined('BASEPATH') OR exit('No direct script access allowed');
39
40/**
41 * Input Class
42 *
43 * Pre-processes global input data for security
44 *
45 * @package		CodeIgniter
46 * @subpackage	Libraries
47 * @category	Input
48 * @author		EllisLab Dev Team
49 * @link		https://codeigniter.com/user_guide/libraries/input.html
50 */
51class CI_Input {
52
53	/**
54	 * IP address of the current user
55	 *
56	 * @var	string
57	 */
58	protected $ip_address = FALSE;
59
60	/**
61	 * Allow GET array flag
62	 *
63	 * If set to FALSE, then $_GET will be set to an empty array.
64	 *
65	 * @var	bool
66	 */
67	protected $_allow_get_array = TRUE;
68
69	/**
70	 * Standardize new lines flag
71	 *
72	 * If set to TRUE, then newlines are standardized.
73	 *
74	 * @var	bool
75	 */
76	protected $_standardize_newlines;
77
78	/**
79	 * Enable XSS flag
80	 *
81	 * Determines whether the XSS filter is always active when
82	 * GET, POST or COOKIE data is encountered.
83	 * Set automatically based on config setting.
84	 *
85	 * @var	bool
86	 */
87	protected $_enable_xss = FALSE;
88
89	/**
90	 * Enable CSRF flag
91	 *
92	 * Enables a CSRF cookie token to be set.
93	 * Set automatically based on config setting.
94	 *
95	 * @var	bool
96	 */
97	protected $_enable_csrf = FALSE;
98
99	/**
100	 * List of all HTTP request headers
101	 *
102	 * @var array
103	 */
104	protected $headers = array();
105
106	/**
107	 * Raw input stream data
108	 *
109	 * Holds a cache of php://input contents
110	 *
111	 * @var	string
112	 */
113	protected $_raw_input_stream;
114
115	/**
116	 * Parsed input stream data
117	 *
118	 * Parsed from php://input at runtime
119	 *
120	 * @see	CI_Input::input_stream()
121	 * @var	array
122	 */
123	protected $_input_stream;
124
125	protected $security;
126	protected $uni;
127
128	// --------------------------------------------------------------------
129
130	/**
131	 * Class constructor
132	 *
133	 * Determines whether to globally enable the XSS processing
134	 * and whether to allow the $_GET array.
135	 *
136	 * @return	void
137	 */
138	public function __construct()
139	{
140		$this->_allow_get_array		= (config_item('allow_get_array') !== FALSE);
141		$this->_enable_xss		= (config_item('global_xss_filtering') === TRUE);
142		$this->_enable_csrf		= (config_item('csrf_protection') === TRUE);
143		$this->_standardize_newlines	= (bool) config_item('standardize_newlines');
144
145		$this->security =& load_class('Security', 'core');
146
147		// Do we need the UTF-8 class?
148		if (UTF8_ENABLED === TRUE)
149		{
150			$this->uni =& load_class('Utf8', 'core');
151		}
152
153		// Sanitize global arrays
154		$this->_sanitize_globals();
155
156		// CSRF Protection check
157		if ($this->_enable_csrf === TRUE && ! is_cli())
158		{
159			$this->security->csrf_verify();
160		}
161
162		log_message('info', 'Input Class Initialized');
163	}
164
165	// --------------------------------------------------------------------
166
167	/**
168	 * Fetch from array
169	 *
170	 * Internal method used to retrieve values from global arrays.
171	 *
172	 * @param	array	&$array		$_GET, $_POST, $_COOKIE, $_SERVER, etc.
173	 * @param	mixed	$index		Index for item to be fetched from $array
174	 * @param	bool	$xss_clean	Whether to apply XSS filtering
175	 * @return	mixed
176	 */
177	protected function _fetch_from_array(&$array, $index = NULL, $xss_clean = NULL)
178	{
179		is_bool($xss_clean) OR $xss_clean = $this->_enable_xss;
180
181		// If $index is NULL, it means that the whole $array is requested
182		isset($index) OR $index = array_keys($array);
183
184		// allow fetching multiple keys at once
185		if (is_array($index))
186		{
187			$output = array();
188			foreach ($index as $key)
189			{
190				$output[$key] = $this->_fetch_from_array($array, $key, $xss_clean);
191			}
192
193			return $output;
194		}
195
196		if (isset($array[$index]))
197		{
198			$value = $array[$index];
199		}
200		elseif (($count = preg_match_all('/(?:^[^\[]+)|\[[^]]*\]/', $index, $matches)) > 1) // Does the index contain array notation
201		{
202			$value = $array;
203			for ($i = 0; $i < $count; $i++)
204			{
205				$key = trim($matches[0][$i], '[]');
206				if ($key === '') // Empty notation will return the value as array
207				{
208					break;
209				}
210
211				if (isset($value[$key]))
212				{
213					$value = $value[$key];
214				}
215				else
216				{
217					return NULL;
218				}
219			}
220		}
221		else
222		{
223			return NULL;
224		}
225
226		return ($xss_clean === TRUE)
227			? $this->security->xss_clean($value)
228			: $value;
229	}
230
231	// --------------------------------------------------------------------
232
233	/**
234	 * Fetch an item from the GET array
235	 *
236	 * @param	mixed	$index		Index for item to be fetched from $_GET
237	 * @param	bool	$xss_clean	Whether to apply XSS filtering
238	 * @return	mixed
239	 */
240	public function get($index = NULL, $xss_clean = NULL)
241	{
242		return $this->_fetch_from_array($_GET, $index, $xss_clean);
243	}
244
245	// --------------------------------------------------------------------
246
247	/**
248	 * Fetch an item from the POST array
249	 *
250	 * @param	mixed	$index		Index for item to be fetched from $_POST
251	 * @param	bool	$xss_clean	Whether to apply XSS filtering
252	 * @return	mixed
253	 */
254	public function post($index = NULL, $xss_clean = NULL)
255	{
256		return $this->_fetch_from_array($_POST, $index, $xss_clean);
257	}
258
259	// --------------------------------------------------------------------
260
261	/**
262	 * Fetch an item from POST data with fallback to GET
263	 *
264	 * @param	string	$index		Index for item to be fetched from $_POST or $_GET
265	 * @param	bool	$xss_clean	Whether to apply XSS filtering
266	 * @return	mixed
267	 */
268	public function post_get($index, $xss_clean = NULL)
269	{
270		return isset($_POST[$index])
271			? $this->post($index, $xss_clean)
272			: $this->get($index, $xss_clean);
273	}
274
275	// --------------------------------------------------------------------
276
277	/**
278	 * Fetch an item from GET data with fallback to POST
279	 *
280	 * @param	string	$index		Index for item to be fetched from $_GET or $_POST
281	 * @param	bool	$xss_clean	Whether to apply XSS filtering
282	 * @return	mixed
283	 */
284	public function get_post($index, $xss_clean = NULL)
285	{
286		return isset($_GET[$index])
287			? $this->get($index, $xss_clean)
288			: $this->post($index, $xss_clean);
289	}
290
291	// --------------------------------------------------------------------
292
293	/**
294	 * Fetch an item from the COOKIE array
295	 *
296	 * @param	mixed	$index		Index for item to be fetched from $_COOKIE
297	 * @param	bool	$xss_clean	Whether to apply XSS filtering
298	 * @return	mixed
299	 */
300	public function cookie($index = NULL, $xss_clean = NULL)
301	{
302		return $this->_fetch_from_array($_COOKIE, $index, $xss_clean);
303	}
304
305	// --------------------------------------------------------------------
306
307	/**
308	 * Fetch an item from the SERVER array
309	 *
310	 * @param	mixed	$index		Index for item to be fetched from $_SERVER
311	 * @param	bool	$xss_clean	Whether to apply XSS filtering
312	 * @return	mixed
313	 */
314	public function server($index, $xss_clean = NULL)
315	{
316		return $this->_fetch_from_array($_SERVER, $index, $xss_clean);
317	}
318
319	// ------------------------------------------------------------------------
320
321	/**
322	 * Fetch an item from the php://input stream
323	 *
324	 * Useful when you need to access PUT, DELETE or PATCH request data.
325	 *
326	 * @param	string	$index		Index for item to be fetched
327	 * @param	bool	$xss_clean	Whether to apply XSS filtering
328	 * @return	mixed
329	 */
330	public function input_stream($index = NULL, $xss_clean = NULL)
331	{
332		// Prior to PHP 5.6, the input stream can only be read once,
333		// so we'll need to check if we have already done that first.
334		if ( ! is_array($this->_input_stream))
335		{
336			// $this->raw_input_stream will trigger __get().
337			parse_str($this->raw_input_stream, $this->_input_stream);
338			is_array($this->_input_stream) OR $this->_input_stream = array();
339		}
340
341		return $this->_fetch_from_array($this->_input_stream, $index, $xss_clean);
342	}
343
344	// ------------------------------------------------------------------------
345
346	/**
347	 * Set cookie
348	 *
349	 * Accepts an arbitrary number of parameters (up to 7) or an associative
350	 * array in the first parameter containing all the values.
351	 *
352	 * @param	string|mixed[]	$name		Cookie name or an array containing parameters
353	 * @param	string		$value		Cookie value
354	 * @param	int		$expire		Cookie expiration time in seconds
355	 * @param	string		$domain		Cookie domain (e.g.: '.yourdomain.com')
356	 * @param	string		$path		Cookie path (default: '/')
357	 * @param	string		$prefix		Cookie name prefix
358	 * @param	bool		$secure		Whether to only transfer cookies via SSL
359	 * @param	bool		$httponly	Whether to only makes the cookie accessible via HTTP (no javascript)
360	 * @return	void
361	 */
362	public function set_cookie($name, $value = '', $expire = '', $domain = '', $path = '/', $prefix = '', $secure = NULL, $httponly = NULL)
363	{
364		if (is_array($name))
365		{
366			// always leave 'name' in last place, as the loop will break otherwise, due to $$item
367			foreach (array('value', 'expire', 'domain', 'path', 'prefix', 'secure', 'httponly', 'name') as $item)
368			{
369				if (isset($name[$item]))
370				{
371					$$item = $name[$item];
372				}
373			}
374		}
375
376		if ($prefix === '' && config_item('cookie_prefix') !== '')
377		{
378			$prefix = config_item('cookie_prefix');
379		}
380
381		if ($domain == '' && config_item('cookie_domain') != '')
382		{
383			$domain = config_item('cookie_domain');
384		}
385
386		if ($path === '/' && config_item('cookie_path') !== '/')
387		{
388			$path = config_item('cookie_path');
389		}
390
391		$secure = ($secure === NULL && config_item('cookie_secure') !== NULL)
392			? (bool) config_item('cookie_secure')
393			: (bool) $secure;
394
395		$httponly = ($httponly === NULL && config_item('cookie_httponly') !== NULL)
396			? (bool) config_item('cookie_httponly')
397			: (bool) $httponly;
398
399		if ( ! is_numeric($expire))
400		{
401			$expire = time() - 86500;
402		}
403		else
404		{
405			$expire = ($expire > 0) ? time() + $expire : 0;
406		}
407
408		setcookie($prefix.$name, $value, $expire, $path, $domain, $secure, $httponly);
409	}
410
411	// --------------------------------------------------------------------
412
413	/**
414	 * Fetch the IP Address
415	 *
416	 * Determines and validates the visitor's IP address.
417	 *
418	 * @return	string	IP address
419	 */
420	public function ip_address()
421	{
422		if ($this->ip_address !== FALSE)
423		{
424			return $this->ip_address;
425		}
426
427		$proxy_ips = config_item('proxy_ips');
428		if ( ! empty($proxy_ips) && ! is_array($proxy_ips))
429		{
430			$proxy_ips = explode(',', str_replace(' ', '', $proxy_ips));
431		}
432
433		$this->ip_address = $this->server('REMOTE_ADDR');
434
435		if ($proxy_ips)
436		{
437			foreach (array('HTTP_X_FORWARDED_FOR', 'HTTP_CLIENT_IP', 'HTTP_X_CLIENT_IP', 'HTTP_X_CLUSTER_CLIENT_IP') as $header)
438			{
439				if (($spoof = $this->server($header)) !== NULL)
440				{
441					// Some proxies typically list the whole chain of IP
442					// addresses through which the client has reached us.
443					// e.g. client_ip, proxy_ip1, proxy_ip2, etc.
444					sscanf($spoof, '%[^,]', $spoof);
445
446					if ( ! $this->valid_ip($spoof))
447					{
448						$spoof = NULL;
449					}
450					else
451					{
452						break;
453					}
454				}
455			}
456
457			if ($spoof)
458			{
459				for ($i = 0, $c = count($proxy_ips); $i < $c; $i++)
460				{
461					// Check if we have an IP address or a subnet
462					if (strpos($proxy_ips[$i], '/') === FALSE)
463					{
464						// An IP address (and not a subnet) is specified.
465						// We can compare right away.
466						if ($proxy_ips[$i] === $this->ip_address)
467						{
468							$this->ip_address = $spoof;
469							break;
470						}
471
472						continue;
473					}
474
475					// We have a subnet ... now the heavy lifting begins
476					isset($separator) OR $separator = $this->valid_ip($this->ip_address, 'ipv6') ? ':' : '.';
477
478					// If the proxy entry doesn't match the IP protocol - skip it
479					if (strpos($proxy_ips[$i], $separator) === FALSE)
480					{
481						continue;
482					}
483
484					// Convert the REMOTE_ADDR IP address to binary, if needed
485					if ( ! isset($ip, $sprintf))
486					{
487						if ($separator === ':')
488						{
489							// Make sure we're have the "full" IPv6 format
490							$ip = explode(':',
491								str_replace('::',
492									str_repeat(':', 9 - substr_count($this->ip_address, ':')),
493									$this->ip_address
494								)
495							);
496
497							for ($j = 0; $j < 8; $j++)
498							{
499								$ip[$j] = intval($ip[$j], 16);
500							}
501
502							$sprintf = '%016b%016b%016b%016b%016b%016b%016b%016b';
503						}
504						else
505						{
506							$ip = explode('.', $this->ip_address);
507							$sprintf = '%08b%08b%08b%08b';
508						}
509
510						$ip = vsprintf($sprintf, $ip);
511					}
512
513					// Split the netmask length off the network address
514					sscanf($proxy_ips[$i], '%[^/]/%d', $netaddr, $masklen);
515
516					// Again, an IPv6 address is most likely in a compressed form
517					if ($separator === ':')
518					{
519						$netaddr = explode(':', str_replace('::', str_repeat(':', 9 - substr_count($netaddr, ':')), $netaddr));
520						for ($j = 0; $j < 8; $j++)
521						{
522							$netaddr[$j] = intval($netaddr[$j], 16);
523						}
524					}
525					else
526					{
527						$netaddr = explode('.', $netaddr);
528					}
529
530					// Convert to binary and finally compare
531					if (strncmp($ip, vsprintf($sprintf, $netaddr), $masklen) === 0)
532					{
533						$this->ip_address = $spoof;
534						break;
535					}
536				}
537			}
538		}
539
540		if ( ! $this->valid_ip($this->ip_address))
541		{
542			return $this->ip_address = '0.0.0.0';
543		}
544
545		return $this->ip_address;
546	}
547
548	// --------------------------------------------------------------------
549
550	/**
551	 * Validate IP Address
552	 *
553	 * @param	string	$ip	IP address
554	 * @param	string	$which	IP protocol: 'ipv4' or 'ipv6'
555	 * @return	bool
556	 */
557	public function valid_ip($ip, $which = '')
558	{
559		switch (strtolower($which))
560		{
561			case 'ipv4':
562				$which = FILTER_FLAG_IPV4;
563				break;
564			case 'ipv6':
565				$which = FILTER_FLAG_IPV6;
566				break;
567			default:
568				$which = NULL;
569				break;
570		}
571
572		return (bool) filter_var($ip, FILTER_VALIDATE_IP, $which);
573	}
574
575	// --------------------------------------------------------------------
576
577	/**
578	 * Fetch User Agent string
579	 *
580	 * @return	string|null	User Agent string or NULL if it doesn't exist
581	 */
582	public function user_agent($xss_clean = NULL)
583	{
584		return $this->_fetch_from_array($_SERVER, 'HTTP_USER_AGENT', $xss_clean);
585	}
586
587	// --------------------------------------------------------------------
588
589	/**
590	 * Sanitize Globals
591	 *
592	 * Internal method serving for the following purposes:
593	 *
594	 *	- Unsets $_GET data, if query strings are not enabled
595	 *	- Cleans POST, COOKIE and SERVER data
596	 * 	- Standardizes newline characters to PHP_EOL
597	 *
598	 * @return	void
599	 */
600	protected function _sanitize_globals()
601	{
602		// Is $_GET data allowed? If not we'll set the $_GET to an empty array
603		if ($this->_allow_get_array === FALSE)
604		{
605			$_GET = array();
606		}
607		elseif (is_array($_GET))
608		{
609			foreach ($_GET as $key => $val)
610			{
611				$_GET[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
612			}
613		}
614
615		// Clean $_POST Data
616		if (is_array($_POST))
617		{
618			foreach ($_POST as $key => $val)
619			{
620				$_POST[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
621			}
622		}
623
624		// Clean $_COOKIE Data
625		if (is_array($_COOKIE))
626		{
627			// Also get rid of specially treated cookies that might be set by a server
628			// or silly application, that are of no use to a CI application anyway
629			// but that when present will trip our 'Disallowed Key Characters' alarm
630			// http://www.ietf.org/rfc/rfc2109.txt
631			// note that the key names below are single quoted strings, and are not PHP variables
632			unset(
633				$_COOKIE['$Version'],
634				$_COOKIE['$Path'],
635				$_COOKIE['$Domain']
636			);
637
638			foreach ($_COOKIE as $key => $val)
639			{
640				if (($cookie_key = $this->_clean_input_keys($key)) !== FALSE)
641				{
642					$_COOKIE[$cookie_key] = $this->_clean_input_data($val);
643				}
644				else
645				{
646					unset($_COOKIE[$key]);
647				}
648			}
649		}
650
651		// Sanitize PHP_SELF
652		$_SERVER['PHP_SELF'] = strip_tags($_SERVER['PHP_SELF']);
653
654		log_message('debug', 'Global POST, GET and COOKIE data sanitized');
655	}
656
657	// --------------------------------------------------------------------
658
659	/**
660	 * Clean Input Data
661	 *
662	 * Internal method that aids in escaping data and
663	 * standardizing newline characters to PHP_EOL.
664	 *
665	 * @param	string|string[]	$str	Input string(s)
666	 * @return	string
667	 */
668	protected function _clean_input_data($str)
669	{
670		if (is_array($str))
671		{
672			$new_array = array();
673			foreach (array_keys($str) as $key)
674			{
675				$new_array[$this->_clean_input_keys($key)] = $this->_clean_input_data($str[$key]);
676			}
677			return $new_array;
678		}
679
680		/* We strip slashes if magic quotes is on to keep things consistent
681
682		   NOTE: In PHP 5.4 get_magic_quotes_gpc() will always return 0 and
683		         it will probably not exist in future versions at all.
684		*/
685		if ( ! is_php('5.4') && get_magic_quotes_gpc())
686		{
687			$str = stripslashes($str);
688		}
689
690		// Clean UTF-8 if supported
691		if (UTF8_ENABLED === TRUE)
692		{
693			$str = $this->uni->clean_string($str);
694		}
695
696		// Remove control characters
697		$str = remove_invisible_characters($str, FALSE);
698
699		// Standardize newlines if needed
700		if ($this->_standardize_newlines === TRUE)
701		{
702			return preg_replace('/(?:\r\n|[\r\n])/', PHP_EOL, $str);
703		}
704
705		return $str;
706	}
707
708	// --------------------------------------------------------------------
709
710	/**
711	 * Clean Keys
712	 *
713	 * Internal method that helps to prevent malicious users
714	 * from trying to exploit keys we make sure that keys are
715	 * only named with alpha-numeric text and a few other items.
716	 *
717	 * @param	string	$str	Input string
718	 * @param	bool	$fatal	Whether to terminate script exection
719	 *				or to return FALSE if an invalid
720	 *				key is encountered
721	 * @return	string|bool
722	 */
723	protected function _clean_input_keys($str, $fatal = TRUE)
724	{
725		if ( ! preg_match('/^[a-z0-9:_\/|-]+$/i', $str))
726		{
727			if ($fatal === TRUE)
728			{
729				return FALSE;
730			}
731			else
732			{
733				set_status_header(503);
734				echo 'Disallowed Key Characters.';
735				exit(7); // EXIT_USER_INPUT
736			}
737		}
738
739		// Clean UTF-8 if supported
740		if (UTF8_ENABLED === TRUE)
741		{
742			return $this->uni->clean_string($str);
743		}
744
745		return $str;
746	}
747
748	// --------------------------------------------------------------------
749
750	/**
751	 * Request Headers
752	 *
753	 * @param	bool	$xss_clean	Whether to apply XSS filtering
754	 * @return	array
755	 */
756	public function request_headers($xss_clean = FALSE)
757	{
758		// If header is already defined, return it immediately
759		if ( ! empty($this->headers))
760		{
761			return $this->_fetch_from_array($this->headers, NULL, $xss_clean);
762		}
763
764		// In Apache, you can simply call apache_request_headers()
765		if (function_exists('apache_request_headers'))
766		{
767			$this->headers = apache_request_headers();
768		}
769		else
770		{
771			isset($_SERVER['CONTENT_TYPE']) && $this->headers['Content-Type'] = $_SERVER['CONTENT_TYPE'];
772
773			foreach ($_SERVER as $key => $val)
774			{
775				if (sscanf($key, 'HTTP_%s', $header) === 1)
776				{
777					// take SOME_HEADER and turn it into Some-Header
778					$header = str_replace('_', ' ', strtolower($header));
779					$header = str_replace(' ', '-', ucwords($header));
780
781					$this->headers[$header] = $_SERVER[$key];
782				}
783			}
784		}
785
786		return $this->_fetch_from_array($this->headers, NULL, $xss_clean);
787	}
788
789	// --------------------------------------------------------------------
790
791	/**
792	 * Get Request Header
793	 *
794	 * Returns the value of a single member of the headers class member
795	 *
796	 * @param	string		$index		Header name
797	 * @param	bool		$xss_clean	Whether to apply XSS filtering
798	 * @return	string|null	The requested header on success or NULL on failure
799	 */
800	public function get_request_header($index, $xss_clean = FALSE)
801	{
802		static $headers;
803
804		if ( ! isset($headers))
805		{
806			empty($this->headers) && $this->request_headers();
807			foreach ($this->headers as $key => $value)
808			{
809				$headers[strtolower($key)] = $value;
810			}
811		}
812
813		$index = strtolower($index);
814
815		if ( ! isset($headers[$index]))
816		{
817			return NULL;
818		}
819
820		return ($xss_clean === TRUE)
821			? $this->security->xss_clean($headers[$index])
822			: $headers[$index];
823	}
824
825	// --------------------------------------------------------------------
826
827	/**
828	 * Is AJAX request?
829	 *
830	 * Test to see if a request contains the HTTP_X_REQUESTED_WITH header.
831	 *
832	 * @return 	bool
833	 */
834	public function is_ajax_request()
835	{
836		return ( ! empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) === 'xmlhttprequest');
837	}
838
839	// --------------------------------------------------------------------
840
841	/**
842	 * Is CLI request?
843	 *
844	 * Test to see if a request was made from the command line.
845	 *
846	 * @deprecated	3.0.0	Use is_cli() instead
847	 * @return	bool
848	 */
849	public function is_cli_request()
850	{
851		return is_cli();
852	}
853
854	// --------------------------------------------------------------------
855
856	/**
857	 * Get Request Method
858	 *
859	 * Return the request method
860	 *
861	 * @param	bool	$upper	Whether to return in upper or lower case
862	 *				(default: FALSE)
863	 * @return 	string
864	 */
865	public function method($upper = FALSE)
866	{
867		return ($upper)
868			? strtoupper($this->server('REQUEST_METHOD'))
869			: strtolower($this->server('REQUEST_METHOD'));
870	}
871
872	// ------------------------------------------------------------------------
873
874	/**
875	 * Magic __get()
876	 *
877	 * Allows read access to protected properties
878	 *
879	 * @param	string	$name
880	 * @return	mixed
881	 */
882	public function __get($name)
883	{
884		if ($name === 'raw_input_stream')
885		{
886			isset($this->_raw_input_stream) OR $this->_raw_input_stream = file_get_contents('php://input');
887			return $this->_raw_input_stream;
888		}
889		elseif ($name === 'ip_address')
890		{
891			return $this->ip_address;
892		}
893	}
894
895}
896