system/core/Input.php

   1 <?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
   2 /**
   3  * CodeIgniter
   4  *
   5  * An open source application development framework for PHP 5.1.6 or newer
   6  *
   7  * @package             CodeIgniter
   8  * @author              ExpressionEngine Dev Team
   9  * @copyright   Copyright (c) 2008 - 2011, EllisLab, Inc.
  10  * @license             http://codeigniter.com/user_guide/license.html
  11  * @link                http://codeigniter.com
  12  * @since               Version 1.0
  13  * @filesource
  14  */
  15
  16 // ------------------------------------------------------------------------
  17
  18 /**
  19  * Input Class
  20  *
  21  * Pre-processes global input data for security
  22  *
  23  * @package             CodeIgniter
  24  * @subpackage  Libraries
  25  * @category    Input
  26  * @author              ExpressionEngine Dev Team
  27  * @link                http://codeigniter.com/user_guide/libraries/input.html
  28  */
  29 class CI_Input {
  30
  31         var $ip_address                         = FALSE;
  32         var $user_agent                         = FALSE;
  33         var $_allow_get_array           = TRUE;
  34         var $_standardize_newlines      = TRUE;
  35         var $_enable_xss                        = FALSE; // Set automatically based on config setting
  36         var $_enable_csrf                       = FALSE; // Set automatically based on config setting
  37
  38         protected $headers                      = array();
  39
  40
  41         /**
  42          * Constructor
  43          *
  44          * Sets whether to globally enable the XSS processing
  45          * and whether to allow the $_GET array
  46          *
  47          */
  48         public function __construct()
  49         {
  50                 log_message('debug', "Input Class Initialized");
  51
  52                 $this->_allow_get_array = (config_item('allow_get_array') === TRUE);
  53                 $this->_enable_xss              = (config_item('global_xss_filtering') === TRUE);
  54                 $this->_enable_csrf             = (config_item('csrf_protection') === TRUE);
  55
  56                 global $SEC;
  57                 $this->security =& $SEC;
  58
  59                 // Do we need the UTF-8 class?
  60                 if (UTF8_ENABLED === TRUE)
  61                 {
  62                         global $UNI;
  63                         $this->uni =& $UNI;
  64                 }
  65
  66                 // Sanitize global arrays
  67                 $this->_sanitize_globals();
  68         }
  69
  70         // --------------------------------------------------------------------
  71
  72         /**
  73          * Fetch from array
  74          *
  75          * This is a helper function to retrieve values from global arrays
  76          *
  77          * @access      private
  78          * @param       array
  79          * @param       string
  80          * @param       bool
  81          * @return      string
  82          */
  83         function _fetch_from_array(&$array, $index = '', $xss_clean = FALSE)
  84         {
  85                 if ( ! isset($array[$index]))
  86                 {
  87                         return FALSE;
  88                 }
  89
  90                 if ($xss_clean === TRUE)
  91                 {
  92                         return $this->security->xss_clean($array[$index]);
  93                 }
  94
  95                 return $array[$index];
  96         }
  97
  98         // --------------------------------------------------------------------
  99
 100         /**
 101         * Fetch an item from the GET array
 102         *
 103         * @access       public
 104         * @param        string
 105         * @param        bool
 106         * @return       string
 107         */
 108         function get($index = NULL, $xss_clean = FALSE)
 109         {
 110                 // Check if a field has been provided
 111                 if ($index === NULL AND ! empty($_GET))
 112                 {
 113                         $get = array();
 114
 115                         // loop through the full _GET array
 116                         foreach (array_keys($_GET) as $key)
 117                         {
 118                                 $get[$key] = $this->_fetch_from_array($_GET, $key, $xss_clean);
 119                         }
 120                         return $get;
 121                 }
 122
 123                 return $this->_fetch_from_array($_GET, $index, $xss_clean);
 124         }
 125
 126         // --------------------------------------------------------------------
 127
 128         /**
 129         * Fetch an item from the POST array
 130         *
 131         * @access       public
 132         * @param        string
 133         * @param        bool
 134         * @return       string
 135         */
 136         function post($index = NULL, $xss_clean = FALSE)
 137         {
 138                 // Check if a field has been provided
 139                 if ($index === NULL AND ! empty($_POST))
 140                 {
 141                         $post = array();
 142
 143                         // Loop through the full _POST array and return it
 144                         foreach (array_keys($_POST) as $key)
 145                         {
 146                                 $post[$key] = $this->_fetch_from_array($_POST, $key, $xss_clean);
 147                         }
 148                         return $post;
 149                 }
 150
 151                 return $this->_fetch_from_array($_POST, $index, $xss_clean);
 152         }
 153
 154
 155         // --------------------------------------------------------------------
 156
 157         /**
 158         * Fetch an item from either the GET array or the POST
 159         *
 160         * @access       public
 161         * @param        string  The index key
 162         * @param        bool    XSS cleaning
 163         * @return       string
 164         */
 165         function get_post($index = '', $xss_clean = FALSE)
 166         {
 167                 if ( ! isset($_POST[$index]) )
 168                 {
 169                         return $this->get($index, $xss_clean);
 170                 }
 171                 else
 172                 {
 173                         return $this->post($index, $xss_clean);
 174                 }
 175         }
 176
 177         // --------------------------------------------------------------------
 178
 179         /**
 180         * Fetch an item from the COOKIE array
 181         *
 182         * @access       public
 183         * @param        string
 184         * @param        bool
 185         * @return       string
 186         */
 187         function cookie($index = '', $xss_clean = FALSE)
 188         {
 189                 return $this->_fetch_from_array($_COOKIE, $index, $xss_clean);
 190         }
 191
 192         // ------------------------------------------------------------------------
 193
 194         /**
 195         * Set cookie
 196         *
 197         * Accepts six parameter, or you can submit an associative
 198         * array in the first parameter containing all the values.
 199         *
 200         * @access       public
 201         * @param        mixed
 202         * @param        string  the value of the cookie
 203         * @param        string  the number of seconds until expiration
 204         * @param        string  the cookie domain.  Usually:  .yourdomain.com
 205         * @param        string  the cookie path
 206         * @param        string  the cookie prefix
 207         * @param        bool    true makes the cookie secure
 208         * @return       void
 209         */
 210         function set_cookie($name = '', $value = '', $expire = '', $domain = '', $path = '/', $prefix = '', $secure = FALSE)
 211         {
 212                 if (is_array($name))
 213                 {
 214                         // always leave 'name' in last place, as the loop will break otherwise, due to $$item
 215                         foreach (array('value', 'expire', 'domain', 'path', 'prefix', 'secure', 'name') as $item)
 216                         {
 217                                 if (isset($name[$item]))
 218                                 {
 219                                         $$item = $name[$item];
 220                                 }
 221                         }
 222                 }
 223
 224                 if ($prefix == '' AND config_item('cookie_prefix') != '')
 225                 {
 226                         $prefix = config_item('cookie_prefix');
 227                 }
 228                 if ($domain == '' AND config_item('cookie_domain') != '')
 229                 {
 230                         $domain = config_item('cookie_domain');
 231                 }
 232                 if ($path == '/' AND config_item('cookie_path') != '/')
 233                 {
 234                         $path = config_item('cookie_path');
 235                 }
 236                 if ($secure == FALSE AND config_item('cookie_secure') != FALSE)
 237                 {
 238                         $secure = config_item('cookie_secure');
 239                 }
 240
 241                 if ( ! is_numeric($expire))
 242                 {
 243                         $expire = time() - 86500;
 244                 }
 245                 else
 246                 {
 247                         $expire = ($expire > 0) ? time() + $expire : 0;
 248                 }
 249
 250                 setcookie($prefix.$name, $value, $expire, $path, $domain, $secure);
 251         }
 252
 253         // --------------------------------------------------------------------
 254
 255         /**
 256         * Fetch an item from the SERVER array
 257         *
 258         * @access       public
 259         * @param        string
 260         * @param        bool
 261         * @return       string
 262         */
 263         function server($index = '', $xss_clean = FALSE)
 264         {
 265                 return $this->_fetch_from_array($_SERVER, $index, $xss_clean);
 266         }
 267
 268         // --------------------------------------------------------------------
 269
 270         /**
 271         * Fetch the IP Address
 272         *
 273         * @access       public
 274         * @return       string
 275         */
 276         function ip_address()
 277         {
 278                 if ($this->ip_address !== FALSE)
 279                 {
 280                         return $this->ip_address;
 281                 }
 282
 283                 if (config_item('proxy_ips') != '' && $this->server('HTTP_X_FORWARDED_FOR') && $this->server('REMOTE_ADDR'))
 284                 {
 285                         $proxies = preg_split('/[\s,]/', config_item('proxy_ips'), -1, PREG_SPLIT_NO_EMPTY);
 286                         $proxies = is_array($proxies) ? $proxies : array($proxies);
 287
 288                         $this->ip_address = in_array($_SERVER['REMOTE_ADDR'], $proxies) ? $_SERVER['HTTP_X_FORWARDED_FOR'] : $_SERVER['REMOTE_ADDR'];
 289                 }
 290                 elseif ($this->server('REMOTE_ADDR') AND $this->server('HTTP_CLIENT_IP'))
 291                 {
 292                         $this->ip_address = $_SERVER['HTTP_CLIENT_IP'];
 293                 }
 294                 elseif ($this->server('REMOTE_ADDR'))
 295                 {
 296                         $this->ip_address = $_SERVER['REMOTE_ADDR'];
 297                 }
 298                 elseif ($this->server('HTTP_CLIENT_IP'))
 299                 {
 300                         $this->ip_address = $_SERVER['HTTP_CLIENT_IP'];
 301                 }
 302                 elseif ($this->server('HTTP_X_FORWARDED_FOR'))
 303                 {
 304                         $this->ip_address = $_SERVER['HTTP_X_FORWARDED_FOR'];
 305                 }
 306
 307                 if ($this->ip_address === FALSE)
 308                 {
 309                         $this->ip_address = '0.0.0.0';
 310                         return $this->ip_address;
 311                 }
 312
 313                 if (strpos($this->ip_address, ',') !== FALSE)
 314                 {
 315                         $x = explode(',', $this->ip_address);
 316                         $this->ip_address = trim(end($x));
 317                 }
 318
 319                 if ( ! $this->valid_ip($this->ip_address))
 320                 {
 321                         $this->ip_address = '0.0.0.0';
 322                 }
 323
 324                 return $this->ip_address;
 325         }
 326
 327         // --------------------------------------------------------------------
 328
 329         /**
 330         * Validate IP Address
 331         *
 332         * Updated version suggested by Geert De Deckere
 333         *
 334         * @access       public
 335         * @param        string
 336         * @return       string
 337         */
 338         function valid_ip($ip)
 339         {
 340                 $ip_segments = explode('.', $ip);
 341
 342                 // Always 4 segments needed
 343                 if (count($ip_segments) != 4)
 344                 {
 345                         return FALSE;
 346                 }
 347                 // IP can not start with 0
 348                 if ($ip_segments[0][0] == '0')
 349                 {
 350                         return FALSE;
 351                 }
 352                 // Check each segment
 353                 foreach ($ip_segments as $segment)
 354                 {
 355                         // IP segments must be digits and can not be
 356                         // longer than 3 digits or greater then 255
 357                         if ($segment == '' OR preg_match("/[^0-9]/", $segment) OR $segment > 255 OR strlen($segment) > 3)
 358                         {
 359                                 return FALSE;
 360                         }
 361                 }
 362
 363                 return TRUE;
 364         }
 365
 366         // --------------------------------------------------------------------
 367
 368         /**
 369         * User Agent
 370         *
 371         * @access       public
 372         * @return       string
 373         */
 374         function user_agent()
 375         {
 376                 if ($this->user_agent !== FALSE)
 377                 {
 378                         return $this->user_agent;
 379                 }
 380
 381                 $this->user_agent = ( ! isset($_SERVER['HTTP_USER_AGENT'])) ? FALSE : $_SERVER['HTTP_USER_AGENT'];
 382
 383                 return $this->user_agent;
 384         }
 385
 386         // --------------------------------------------------------------------
 387
 388         /**
 389         * Sanitize Globals
 390         *
 391         * This function does the following:
 392         *
 393         * Unsets $_GET data (if query strings are not enabled)
 394         *
 395         * Unsets all globals if register_globals is enabled
 396         *
 397         * Standardizes newline characters to \n
 398         *
 399         * @access       private
 400         * @return       void
 401         */
 402         function _sanitize_globals()
 403         {
 404                 // It would be "wrong" to unset any of these GLOBALS.
 405                 $protected = array('_SERVER', '_GET', '_POST', '_FILES', '_REQUEST',
 406                                                         '_SESSION', '_ENV', 'GLOBALS', 'HTTP_RAW_POST_DATA',
 407                                                         'system_folder', 'application_folder', 'BM', 'EXT',
 408                                                         'CFG', 'URI', 'RTR', 'OUT', 'IN');
 409
 410                 // Unset globals for securiy.
 411                 // This is effectively the same as register_globals = off
 412                 foreach (array($_GET, $_POST, $_COOKIE) as $global)
 413                 {
 414                         if ( ! is_array($global))
 415                         {
 416                                 if ( ! in_array($global, $protected))
 417                                 {
 418                                         global $$global;
 419                                         $$global = NULL;
 420                                 }
 421                         }
 422                         else
 423                         {
 424                                 foreach ($global as $key => $val)
 425                                 {
 426                                         if ( ! in_array($key, $protected))
 427                                         {
 428                                                 global $$key;
 429                                                 $$key = NULL;
 430                                         }
 431                                 }
 432                         }
 433                 }
 434
 435                 // Is $_GET data allowed? If not we'll set the $_GET to an empty array
 436                 if ($this->_allow_get_array == FALSE)
 437                 {
 438                         $_GET = array();
 439                 }
 440                 else
 441                 {
 442                         if (is_array($_GET) AND count($_GET) > 0)
 443                         {
 444                                 foreach ($_GET as $key => $val)
 445                                 {
 446                                         $_GET[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
 447                                 }
 448                         }
 449                 }
 450
 451                 // Clean $_POST Data
 452                 if (is_array($_POST) AND count($_POST) > 0)
 453                 {
 454                         foreach ($_POST as $key => $val)
 455                         {
 456                                 $_POST[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
 457                         }
 458                 }
 459
 460                 // Clean $_COOKIE Data
 461                 if (is_array($_COOKIE) AND count($_COOKIE) > 0)
 462                 {
 463                         // Also get rid of specially treated cookies that might be set by a server
 464                         // or silly application, that are of no use to a CI application anyway
 465                         // but that when present will trip our 'Disallowed Key Characters' alarm
 466                         // http://www.ietf.org/rfc/rfc2109.txt
 467                         // note that the key names below are single quoted strings, and are not PHP variables
 468                         unset($_COOKIE['$Version']);
 469                         unset($_COOKIE['$Path']);
 470                         unset($_COOKIE['$Domain']);
 471
 472                         foreach ($_COOKIE as $key => $val)
 473                         {
 474                                 $_COOKIE[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
 475                         }
 476                 }
 477
 478                 // Sanitize PHP_SELF
 479                 $_SERVER['PHP_SELF'] = strip_tags($_SERVER['PHP_SELF']);
 480
 481
 482                 // CSRF Protection check
 483                 if ($this->_enable_csrf == TRUE)
 484                 {
 485                         $this->security->csrf_verify();
 486                 }
 487
 488                 log_message('debug', "Global POST and COOKIE data sanitized");
 489         }
 490
 491         // --------------------------------------------------------------------
 492
 493         /**
 494         * Clean Input Data
 495         *
 496         * This is a helper function. It escapes data and
 497         * standardizes newline characters to \n
 498         *
 499         * @access       private
 500         * @param        string
 501         * @return       string
 502         */
 503         function _clean_input_data($str)
 504         {
 505                 if (is_array($str))
 506                 {
 507                         $new_array = array();
 508                         foreach ($str as $key => $val)
 509                         {
 510                                 $new_array[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
 511                         }
 512                         return $new_array;
 513                 }
 514
 515                 // We strip slashes if magic quotes is on to keep things consistent
 516                 if (function_exists('get_magic_quotes_gpc') AND get_magic_quotes_gpc())
 517                 {
 518                         $str = stripslashes($str);
 519                 }
 520
 521                 // Clean UTF-8 if supported
 522                 if (UTF8_ENABLED === TRUE)
 523                 {
 524                         $str = $this->uni->clean_string($str);
 525                 }
 526
 527                 // Remove control characters
 528                 $str = remove_invisible_characters($str);
 529
 530                 // Should we filter the input data?
 531                 if ($this->_enable_xss === TRUE)
 532                 {
 533                         $str = $this->security->xss_clean($str);
 534                 }
 535
 536                 // Standardize newlines if needed
 537                 if ($this->_standardize_newlines == TRUE)
 538                 {
 539                         if (strpos($str, "\r") !== FALSE)
 540                         {
 541                                 $str = str_replace(array("\r\n", "\r", "\r\n\n"), PHP_EOL, $str);
 542                         }
 543                 }
 544
 545                 return $str;
 546         }
 547
 548         // --------------------------------------------------------------------
 549
 550         /**
 551         * Clean Keys
 552         *
 553         * This is a helper function. To prevent malicious users
 554         * from trying to exploit keys we make sure that keys are
 555         * only named with alpha-numeric text and a few other items.
 556         *
 557         * @access       private
 558         * @param        string
 559         * @return       string
 560         */
 561         function _clean_input_keys($str)
 562         {
 563                 if ( ! preg_match("/^[a-z0-9:_\/-]+$/i", $str))
 564                 {
 565                         exit('Disallowed Key Characters.');
 566                 }
 567
 568                 // Clean UTF-8 if supported
 569                 if (UTF8_ENABLED === TRUE)
 570                 {
 571                         $str = $this->uni->clean_string($str);
 572                 }
 573
 574                 return $str;
 575         }
 576
 577         // --------------------------------------------------------------------
 578
 579         /**
 580          * Request Headers
 581          *
 582          * In Apache, you can simply call apache_request_headers(), however for
 583          * people running other webservers the function is undefined.
 584          *
 585          * @return array
 586          */
 587         public function request_headers($xss_clean = FALSE)
 588         {
 589                 // Look at Apache go!
 590                 if (function_exists('apache_request_headers'))
 591                 {
 592                         $headers = apache_request_headers();
 593                 }
 594                 else
 595                 {
 596                         $headers['Content-Type'] = (isset($_SERVER['CONTENT_TYPE'])) ? $_SERVER['CONTENT_TYPE'] : @getenv('CONTENT_TYPE');
 597
 598                         foreach ($_SERVER as $key => $val)
 599                         {
 600                                 if (strncmp($key, 'HTTP_', 5) === 0)
 601                                 {
 602                                         $headers[substr($key, 5)] = $this->_fetch_from_array($_SERVER, $key, $xss_clean);
 603                                 }
 604                         }
 605                 }
 606
 607                 // take SOME_HEADER and turn it into Some-Header
 608                 foreach ($headers as $key => $val)
 609                 {
 610                         $key = str_replace('_', ' ', strtolower($key));
 611                         $key = str_replace(' ', '-', ucwords($key));
 612
 613                         $this->headers[$key] = $val;
 614                 }
 615
 616                 return $this->headers;
 617         }
 618
 619         // --------------------------------------------------------------------
 620
 621         /**
 622          * Get Request Header
 623          *
 624          * Returns the value of a single member of the headers class member
 625          *
 626          * @param       string          array key for $this->headers
 627          * @param       boolean         XSS Clean or not
 628          * @return      mixed           FALSE on failure, string on success
 629          */
 630         public function get_request_header($index, $xss_clean = FALSE)
 631         {
 632                 if (empty($this->headers))
 633                 {
 634                         $this->request_headers();
 635                 }
 636
 637                 if ( ! isset($this->headers[$index]))
 638                 {
 639                         return FALSE;
 640                 }
 641
 642                 if ($xss_clean === TRUE)
 643                 {
 644                         return $this->security->xss_clean($this->headers[$index]);
 645                 }
 646
 647                 return $this->headers[$index];
 648         }
 649
 650         // --------------------------------------------------------------------
 651
 652         /**
 653          * Is ajax Request?
 654          *
 655          * Test to see if a request contains the HTTP_X_REQUESTED_WITH header
 656          *
 657          * @return      boolean
 658          */
 659         public function is_ajax_request()
 660         {
 661                 return ($this->server('HTTP_X_REQUESTED_WITH') === 'XMLHttpRequest');
 662         }
 663
 664         // --------------------------------------------------------------------
 665
 666         /**
 667          * Is cli Request?
 668          *
 669          * Test to see if a request was made from the command line
 670          *
 671          * @return      boolean
 672          */
 673         public function is_cli_request()
 674         {
 675                 return (bool) defined('STDIN');
 676         }
 677
 678 }
 679 // END Input class
 680
 681 /* End of file Input.php */
 682 /* Location: ./system/core/Input.php */