Search moodle.org's
Developer Documentation

See Release Notes

  • Bug fixes for general core bugs in 4.0.x will end 8 May 2023 (12 months).
  • Bug fixes for security issues in 4.0.x will end 13 November 2023 (18 months).
  • PHP version: minimum PHP 7.3.0 Note: the minimum PHP version has increased since Moodle 3.10. PHP 7.4.x is also supported.

Differences Between: [Versions 310 and 400] [Versions 39 and 400] [Versions 400 and 401] [Versions 400 and 402] [Versions 400 and 403]

   1  <?php
   2  /**
   3   * SimplePie
   4   *
   5   * A PHP-Based RSS and Atom Feed Framework.
   6   * Takes the hard work out of managing a complete RSS/Atom solution.
   7   *
   8   * Copyright (c) 2004-2016, Ryan Parman, Sam Sneddon, Ryan McCue, and contributors
   9   * All rights reserved.
  10   *
  11   * Redistribution and use in source and binary forms, with or without modification, are
  12   * permitted provided that the following conditions are met:
  13   *
  14   * 	 * Redistributions of source code must retain the above copyright notice, this list of
  15   * 	   conditions and the following disclaimer.
  16   *
  17   * 	 * Redistributions in binary form must reproduce the above copyright notice, this list
  18   * 	   of conditions and the following disclaimer in the documentation and/or other materials
  19   * 	   provided with the distribution.
  20   *
  21   * 	 * Neither the name of the SimplePie Team nor the names of its contributors may be used
  22   * 	   to endorse or promote products derived from this software without specific prior
  23   * 	   written permission.
  24   *
  25   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
  26   * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  27   * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS
  28   * AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  30   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  31   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  32   * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  33   * POSSIBILITY OF SUCH DAMAGE.
  34   *
  35   * @package SimplePie
  36   * @copyright 2004-2016 Ryan Parman, Sam Sneddon, Ryan McCue
  37   * @author Ryan Parman
  38   * @author Sam Sneddon
  39   * @author Ryan McCue
  40   * @link http://simplepie.org/ SimplePie
  41   * @license http://www.opensource.org/licenses/bsd-license.php BSD License
  42   */
  43  
  44  
  45  /**
  46   * Content-type sniffing
  47   *
  48   * Based on the rules in http://tools.ietf.org/html/draft-abarth-mime-sniff-06
  49   *
  50   * This is used since we can't always trust Content-Type headers, and is based
  51   * upon the HTML5 parsing rules.
  52   *
  53   *
  54   * This class can be overloaded with {@see SimplePie::set_content_type_sniffer_class()}
  55   *
  56   * @package SimplePie
  57   * @subpackage HTTP
  58   */
  59  class SimplePie_Content_Type_Sniffer
  60  {
  61  	 /**
  62  	  * File object
  63  	  *
  64  	  * @var SimplePie_File
  65  	  */
  66  	 var $file;
  67  
  68  	 /**
  69  	  * Create an instance of the class with the input file
  70  	  *
  71  	  * @param SimplePie_Content_Type_Sniffer $file Input file
  72  	  */
  73  	public function __construct($file)
  74  	 {
  75  	 	 $this->file = $file;
  76  	 }
  77  
  78  	 /**
  79  	  * Get the Content-Type of the specified file
  80  	  *
  81  	  * @return string Actual Content-Type
  82  	  */
  83  	public function get_type()
  84  	 {
  85  	 	 if (isset($this->file->headers['content-type']))
  86  	 	 {
  87  	 	 	 if (!isset($this->file->headers['content-encoding'])
  88  	 	 	 	 && ($this->file->headers['content-type'] === 'text/plain'
  89  	 	 	 	 	 || $this->file->headers['content-type'] === 'text/plain; charset=ISO-8859-1'
  90  	 	 	 	 	 || $this->file->headers['content-type'] === 'text/plain; charset=iso-8859-1'
  91  	 	 	 	 	 || $this->file->headers['content-type'] === 'text/plain; charset=UTF-8'))
  92  	 	 	 {
  93  	 	 	 	 return $this->text_or_binary();
  94  	 	 	 }
  95  
  96  	 	 	 if (($pos = strpos($this->file->headers['content-type'], ';')) !== false)
  97  	 	 	 {
  98  	 	 	 	 $official = substr($this->file->headers['content-type'], 0, $pos);
  99  	 	 	 }
 100  	 	 	 else
 101  	 	 	 {
 102  	 	 	 	 $official = $this->file->headers['content-type'];
 103  	 	 	 }
 104  	 	 	 $official = trim(strtolower($official));
 105  
 106  	 	 	 if ($official === 'unknown/unknown'
 107  	 	 	 	 || $official === 'application/unknown')
 108  	 	 	 {
 109  	 	 	 	 return $this->unknown();
 110  	 	 	 }
 111  	 	 	 elseif (substr($official, -4) === '+xml'
 112  	 	 	 	 || $official === 'text/xml'
 113  	 	 	 	 || $official === 'application/xml')
 114  	 	 	 {
 115  	 	 	 	 return $official;
 116  	 	 	 }
 117  	 	 	 elseif (substr($official, 0, 6) === 'image/')
 118  	 	 	 {
 119  	 	 	 	 if ($return = $this->image())
 120  	 	 	 	 {
 121  	 	 	 	 	 return $return;
 122  	 	 	 	 }
 123  
 124  	 	 	 	 return $official;
 125  	 	 	 }
 126  	 	 	 elseif ($official === 'text/html')
 127  	 	 	 {
 128  	 	 	 	 return $this->feed_or_html();
 129  	 	 	 }
 130  
 131  	 	 	 return $official;
 132  	 	 }
 133  
 134  	 	 return $this->unknown();
 135  	 }
 136  
 137  	 /**
 138  	  * Sniff text or binary
 139  	  *
 140  	  * @return string Actual Content-Type
 141  	  */
 142  	public function text_or_binary()
 143  	 {
 144  	 	 if (substr($this->file->body, 0, 2) === "\xFE\xFF"
 145  	 	 	 || substr($this->file->body, 0, 2) === "\xFF\xFE"
 146  	 	 	 || substr($this->file->body, 0, 4) === "\x00\x00\xFE\xFF"
 147  	 	 	 || substr($this->file->body, 0, 3) === "\xEF\xBB\xBF")
 148  	 	 {
 149  	 	 	 return 'text/plain';
 150  	 	 }
 151  	 	 elseif (preg_match('/[\x00-\x08\x0E-\x1A\x1C-\x1F]/', $this->file->body))
 152  	 	 {
 153  	 	 	 return 'application/octet-stream';
 154  	 	 }
 155  
 156  	 	 return 'text/plain';
 157  	 }
 158  
 159  	 /**
 160  	  * Sniff unknown
 161  	  *
 162  	  * @return string Actual Content-Type
 163  	  */
 164  	public function unknown()
 165  	 {
 166  	 	 $ws = strspn($this->file->body, "\x09\x0A\x0B\x0C\x0D\x20");
 167  	 	 if (strtolower(substr($this->file->body, $ws, 14)) === '<!doctype html'
 168  	 	 	 || strtolower(substr($this->file->body, $ws, 5)) === '<html'
 169  	 	 	 || strtolower(substr($this->file->body, $ws, 7)) === '<script')
 170  	 	 {
 171  	 	 	 return 'text/html';
 172  	 	 }
 173  	 	 elseif (substr($this->file->body, 0, 5) === '%PDF-')
 174  	 	 {
 175  	 	 	 return 'application/pdf';
 176  	 	 }
 177  	 	 elseif (substr($this->file->body, 0, 11) === '%!PS-Adobe-')
 178  	 	 {
 179  	 	 	 return 'application/postscript';
 180  	 	 }
 181  	 	 elseif (substr($this->file->body, 0, 6) === 'GIF87a'
 182  	 	 	 || substr($this->file->body, 0, 6) === 'GIF89a')
 183  	 	 {
 184  	 	 	 return 'image/gif';
 185  	 	 }
 186  	 	 elseif (substr($this->file->body, 0, 8) === "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A")
 187  	 	 {
 188  	 	 	 return 'image/png';
 189  	 	 }
 190  	 	 elseif (substr($this->file->body, 0, 3) === "\xFF\xD8\xFF")
 191  	 	 {
 192  	 	 	 return 'image/jpeg';
 193  	 	 }
 194  	 	 elseif (substr($this->file->body, 0, 2) === "\x42\x4D")
 195  	 	 {
 196  	 	 	 return 'image/bmp';
 197  	 	 }
 198  	 	 elseif (substr($this->file->body, 0, 4) === "\x00\x00\x01\x00")
 199  	 	 {
 200  	 	 	 return 'image/vnd.microsoft.icon';
 201  	 	 }
 202  
 203  	 	 return $this->text_or_binary();
 204  	 }
 205  
 206  	 /**
 207  	  * Sniff images
 208  	  *
 209  	  * @return string Actual Content-Type
 210  	  */
 211  	public function image()
 212  	 {
 213  	 	 if (substr($this->file->body, 0, 6) === 'GIF87a'
 214  	 	 	 || substr($this->file->body, 0, 6) === 'GIF89a')
 215  	 	 {
 216  	 	 	 return 'image/gif';
 217  	 	 }
 218  	 	 elseif (substr($this->file->body, 0, 8) === "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A")
 219  	 	 {
 220  	 	 	 return 'image/png';
 221  	 	 }
 222  	 	 elseif (substr($this->file->body, 0, 3) === "\xFF\xD8\xFF")
 223  	 	 {
 224  	 	 	 return 'image/jpeg';
 225  	 	 }
 226  	 	 elseif (substr($this->file->body, 0, 2) === "\x42\x4D")
 227  	 	 {
 228  	 	 	 return 'image/bmp';
 229  	 	 }
 230  	 	 elseif (substr($this->file->body, 0, 4) === "\x00\x00\x01\x00")
 231  	 	 {
 232  	 	 	 return 'image/vnd.microsoft.icon';
 233  	 	 }
 234  
 235  	 	 return false;
 236  	 }
 237  
 238  	 /**
 239  	  * Sniff HTML
 240  	  *
 241  	  * @return string Actual Content-Type
 242  	  */
 243  	public function feed_or_html()
 244  	 {
 245  	 	 $len = strlen($this->file->body);
 246  	 	 $pos = strspn($this->file->body, "\x09\x0A\x0D\x20\xEF\xBB\xBF");
 247  
 248  	 	 while ($pos < $len)
 249  	 	 {
 250  	 	 	 switch ($this->file->body[$pos])
 251  	 	 	 {
 252  	 	 	 	 case "\x09":
 253  	 	 	 	 case "\x0A":
 254  	 	 	 	 case "\x0D":
 255  	 	 	 	 case "\x20":
 256  	 	 	 	 	 $pos += strspn($this->file->body, "\x09\x0A\x0D\x20", $pos);
 257  	 	 	 	 	 continue 2;
 258  
 259  	 	 	 	 case '<':
 260  	 	 	 	 	 $pos++;
 261  	 	 	 	 	 break;
 262  
 263  	 	 	 	 default:
 264  	 	 	 	 	 return 'text/html';
 265  	 	 	 }
 266  
 267  	 	 	 if (substr($this->file->body, $pos, 3) === '!--')
 268  	 	 	 {
 269  	 	 	 	 $pos += 3;
 270  	 	 	 	 if ($pos < $len && ($pos = strpos($this->file->body, '-->', $pos)) !== false)
 271  	 	 	 	 {
 272  	 	 	 	 	 $pos += 3;
 273  	 	 	 	 }
 274  	 	 	 	 else
 275  	 	 	 	 {
 276  	 	 	 	 	 return 'text/html';
 277  	 	 	 	 }
 278  	 	 	 }
 279  	 	 	 elseif (substr($this->file->body, $pos, 1) === '!')
 280  	 	 	 {
 281  	 	 	 	 if ($pos < $len && ($pos = strpos($this->file->body, '>', $pos)) !== false)
 282  	 	 	 	 {
 283  	 	 	 	 	 $pos++;
 284  	 	 	 	 }
 285  	 	 	 	 else
 286  	 	 	 	 {
 287  	 	 	 	 	 return 'text/html';
 288  	 	 	 	 }
 289  	 	 	 }
 290  	 	 	 elseif (substr($this->file->body, $pos, 1) === '?')
 291  	 	 	 {
 292  	 	 	 	 if ($pos < $len && ($pos = strpos($this->file->body, '?>', $pos)) !== false)
 293  	 	 	 	 {
 294  	 	 	 	 	 $pos += 2;
 295  	 	 	 	 }
 296  	 	 	 	 else
 297  	 	 	 	 {
 298  	 	 	 	 	 return 'text/html';
 299  	 	 	 	 }
 300  	 	 	 }
 301  	 	 	 elseif (substr($this->file->body, $pos, 3) === 'rss'
 302  	 	 	 	 || substr($this->file->body, $pos, 7) === 'rdf:RDF')
 303  	 	 	 {
 304  	 	 	 	 return 'application/rss+xml';
 305  	 	 	 }
 306  	 	 	 elseif (substr($this->file->body, $pos, 4) === 'feed')
 307  	 	 	 {
 308  	 	 	 	 return 'application/atom+xml';
 309  	 	 	 }
 310  	 	 	 else
 311  	 	 	 {
 312  	 	 	 	 return 'text/html';
 313  	 	 	 }
 314  	 	 }
 315  
 316  	 	 return 'text/html';
 317  	 }
 318  }