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   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   * HTTP Response Parser
  47   *
  48   * @package SimplePie
  49   * @subpackage HTTP
  50   */
  51  class SimplePie_HTTP_Parser
  52  {
  53      /**
  54       * HTTP Version
  55       *
  56       * @var float
  57       */
  58      public $http_version = 0.0;
  59  
  60      /**
  61       * Status code
  62       *
  63       * @var int
  64       */
  65      public $status_code = 0;
  66  
  67      /**
  68       * Reason phrase
  69       *
  70       * @var string
  71       */
  72      public $reason = '';
  73  
  74      /**
  75       * Key/value pairs of the headers
  76       *
  77       * @var array
  78       */
  79      public $headers = array();
  80  
  81      /**
  82       * Body of the response
  83       *
  84       * @var string
  85       */
  86      public $body = '';
  87  
  88      /**
  89       * Current state of the state machine
  90       *
  91       * @var string
  92       */
  93      protected $state = 'http_version';
  94  
  95      /**
  96       * Input data
  97       *
  98       * @var string
  99       */
 100      protected $data = '';
 101  
 102      /**
 103       * Input data length (to avoid calling strlen() everytime this is needed)
 104       *
 105       * @var int
 106       */
 107      protected $data_length = 0;
 108  
 109      /**
 110       * Current position of the pointer
 111       *
 112       * @var int
 113       */
 114      protected $position = 0;
 115  
 116      /**
 117       * Name of the hedaer currently being parsed
 118       *
 119       * @var string
 120       */
 121      protected $name = '';
 122  
 123      /**
 124       * Value of the hedaer currently being parsed
 125       *
 126       * @var string
 127       */
 128      protected $value = '';
 129  
 130      /**
 131       * Create an instance of the class with the input data
 132       *
 133       * @param string $data Input data
 134       */
 135  	public function __construct($data)
 136      {
 137          $this->data = $data;
 138          $this->data_length = strlen($this->data);
 139      }
 140  
 141      /**
 142       * Parse the input data
 143       *
 144       * @return bool true on success, false on failure
 145       */
 146  	public function parse()
 147      {
 148          while ($this->state && $this->state !== 'emit' && $this->has_data())
 149          {
 150              $state = $this->state;
 151              $this->$state();
 152          }
 153          $this->data = '';
 154          if ($this->state === 'emit' || $this->state === 'body')
 155          {
 156              return true;
 157          }
 158  
 159          $this->http_version = '';
 160          $this->status_code = '';
 161          $this->reason = '';
 162          $this->headers = array();
 163          $this->body = '';
 164          return false;
 165      }
 166  
 167      /**
 168       * Check whether there is data beyond the pointer
 169       *
 170       * @return bool true if there is further data, false if not
 171       */
 172  	protected function has_data()
 173      {
 174          return (bool) ($this->position < $this->data_length);
 175      }
 176  
 177      /**
 178       * See if the next character is LWS
 179       *
 180       * @return bool true if the next character is LWS, false if not
 181       */
 182  	protected function is_linear_whitespace()
 183      {
 184          return (bool) ($this->data[$this->position] === "\x09"
 185              || $this->data[$this->position] === "\x20"
 186              || ($this->data[$this->position] === "\x0A"
 187                  && isset($this->data[$this->position + 1])
 188                  && ($this->data[$this->position + 1] === "\x09" || $this->data[$this->position + 1] === "\x20")));
 189      }
 190  
 191      /**
 192       * Parse the HTTP version
 193       */
 194  	protected function http_version()
 195      {
 196          if (strpos($this->data, "\x0A") !== false && strtoupper(substr($this->data, 0, 5)) === 'HTTP/')
 197          {
 198              $len = strspn($this->data, '0123456789.', 5);
 199              $this->http_version = substr($this->data, 5, $len);
 200              $this->position += 5 + $len;
 201              if (substr_count($this->http_version, '.') <= 1)
 202              {
 203                  $this->http_version = (float) $this->http_version;
 204                  $this->position += strspn($this->data, "\x09\x20", $this->position);
 205                  $this->state = 'status';
 206              }
 207              else
 208              {
 209                  $this->state = false;
 210              }
 211          }
 212          else
 213          {
 214              $this->state = false;
 215          }
 216      }
 217  
 218      /**
 219       * Parse the status code
 220       */
 221  	protected function status()
 222      {
 223          if ($len = strspn($this->data, '0123456789', $this->position))
 224          {
 225              $this->status_code = (int) substr($this->data, $this->position, $len);
 226              $this->position += $len;
 227              $this->state = 'reason';
 228          }
 229          else
 230          {
 231              $this->state = false;
 232          }
 233      }
 234  
 235      /**
 236       * Parse the reason phrase
 237       */
 238  	protected function reason()
 239      {
 240          $len = strcspn($this->data, "\x0A", $this->position);
 241          $this->reason = trim(substr($this->data, $this->position, $len), "\x09\x0D\x20");
 242          $this->position += $len + 1;
 243          $this->state = 'new_line';
 244      }
 245  
 246      /**
 247       * Deal with a new line, shifting data around as needed
 248       */
 249  	protected function new_line()
 250      {
 251          $this->value = trim($this->value, "\x0D\x20");
 252          if ($this->name !== '' && $this->value !== '')
 253          {
 254              $this->name = strtolower($this->name);
 255              // We should only use the last Content-Type header. c.f. issue #1
 256              if (isset($this->headers[$this->name]) && $this->name !== 'content-type')
 257              {
 258                  $this->headers[$this->name] .= ', ' . $this->value;
 259              }
 260              else
 261              {
 262                  $this->headers[$this->name] = $this->value;
 263              }
 264          }
 265          $this->name = '';
 266          $this->value = '';
 267          if (substr($this->data[$this->position], 0, 2) === "\x0D\x0A")
 268          {
 269              $this->position += 2;
 270              $this->state = 'body';
 271          }
 272          elseif ($this->data[$this->position] === "\x0A")
 273          {
 274              $this->position++;
 275              $this->state = 'body';
 276          }
 277          else
 278          {
 279              $this->state = 'name';
 280          }
 281      }
 282  
 283      /**
 284       * Parse a header name
 285       */
 286  	protected function name()
 287      {
 288          $len = strcspn($this->data, "\x0A:", $this->position);
 289          if (isset($this->data[$this->position + $len]))
 290          {
 291              if ($this->data[$this->position + $len] === "\x0A")
 292              {
 293                  $this->position += $len;
 294                  $this->state = 'new_line';
 295              }
 296              else
 297              {
 298                  $this->name = substr($this->data, $this->position, $len);
 299                  $this->position += $len + 1;
 300                  $this->state = 'value';
 301              }
 302          }
 303          else
 304          {
 305              $this->state = false;
 306          }
 307      }
 308  
 309      /**
 310       * Parse LWS, replacing consecutive LWS characters with a single space
 311       */
 312  	protected function linear_whitespace()
 313      {
 314          do
 315          {
 316              if (substr($this->data, $this->position, 2) === "\x0D\x0A")
 317              {
 318                  $this->position += 2;
 319              }
 320              elseif ($this->data[$this->position] === "\x0A")
 321              {
 322                  $this->position++;
 323              }
 324              $this->position += strspn($this->data, "\x09\x20", $this->position);
 325          } while ($this->has_data() && $this->is_linear_whitespace());
 326          $this->value .= "\x20";
 327      }
 328  
 329      /**
 330       * See what state to move to while within non-quoted header values
 331       */
 332  	protected function value()
 333      {
 334          if ($this->is_linear_whitespace())
 335          {
 336              $this->linear_whitespace();
 337          }
 338          else
 339          {
 340              switch ($this->data[$this->position])
 341              {
 342                  case '"':
 343                      // Workaround for ETags: we have to include the quotes as
 344                      // part of the tag.
 345                      if (strtolower($this->name) === 'etag')
 346                      {
 347                          $this->value .= '"';
 348                          $this->position++;
 349                          $this->state = 'value_char';
 350                          break;
 351                      }
 352                      $this->position++;
 353                      $this->state = 'quote';
 354                      break;
 355  
 356                  case "\x0A":
 357                      $this->position++;
 358                      $this->state = 'new_line';
 359                      break;
 360  
 361                  default:
 362                      $this->state = 'value_char';
 363                      break;
 364              }
 365          }
 366      }
 367  
 368      /**
 369       * Parse a header value while outside quotes
 370       */
 371  	protected function value_char()
 372      {
 373          $len = strcspn($this->data, "\x09\x20\x0A\"", $this->position);
 374          $this->value .= substr($this->data, $this->position, $len);
 375          $this->position += $len;
 376          $this->state = 'value';
 377      }
 378  
 379      /**
 380       * See what state to move to while within quoted header values
 381       */
 382  	protected function quote()
 383      {
 384          if ($this->is_linear_whitespace())
 385          {
 386              $this->linear_whitespace();
 387          }
 388          else
 389          {
 390              switch ($this->data[$this->position])
 391              {
 392                  case '"':
 393                      $this->position++;
 394                      $this->state = 'value';
 395                      break;
 396  
 397                  case "\x0A":
 398                      $this->position++;
 399                      $this->state = 'new_line';
 400                      break;
 401  
 402                  case '\\':
 403                      $this->position++;
 404                      $this->state = 'quote_escaped';
 405                      break;
 406  
 407                  default:
 408                      $this->state = 'quote_char';
 409                      break;
 410              }
 411          }
 412      }
 413  
 414      /**
 415       * Parse a header value while within quotes
 416       */
 417  	protected function quote_char()
 418      {
 419          $len = strcspn($this->data, "\x09\x20\x0A\"\\", $this->position);
 420          $this->value .= substr($this->data, $this->position, $len);
 421          $this->position += $len;
 422          $this->state = 'value';
 423      }
 424  
 425      /**
 426       * Parse an escaped character within quotes
 427       */
 428  	protected function quote_escaped()
 429      {
 430          $this->value .= $this->data[$this->position];
 431          $this->position++;
 432          $this->state = 'quote';
 433      }
 434  
 435      /**
 436       * Parse the body
 437       */
 438  	protected function body()
 439      {
 440          $this->body = substr($this->data, $this->position);
 441          if (!empty($this->headers['transfer-encoding']))
 442          {
 443              unset($this->headers['transfer-encoding']);
 444              $this->state = 'chunked';
 445          }
 446          else
 447          {
 448              $this->state = 'emit';
 449          }
 450      }
 451  
 452      /**
 453       * Parsed a "Transfer-Encoding: chunked" body
 454       */
 455  	protected function chunked()
 456      {
 457          if (!preg_match('/^([0-9a-f]+)[^\r\n]*\r\n/i', trim($this->body)))
 458          {
 459              $this->state = 'emit';
 460              return;
 461          }
 462  
 463          $decoded = '';
 464          $encoded = $this->body;
 465  
 466          while (true)
 467          {
 468              $is_chunked = (bool) preg_match( '/^([0-9a-f]+)[^\r\n]*\r\n/i', $encoded, $matches );
 469              if (!$is_chunked)
 470              {
 471                  // Looks like it's not chunked after all
 472                  $this->state = 'emit';
 473                  return;
 474              }
 475  
 476              $length = hexdec(trim($matches[1]));
 477              if ($length === 0)
 478              {
 479                  // Ignore trailer headers
 480                  $this->state = 'emit';
 481                  $this->body = $decoded;
 482                  return;
 483              }
 484  
 485              $chunk_length = strlen($matches[0]);
 486              $decoded .= $part = substr($encoded, $chunk_length, $length);
 487              $encoded = substr($encoded, $chunk_length + $length + 2);
 488  
 489              if (trim($encoded) === '0' || empty($encoded))
 490              {
 491                  $this->state = 'emit';
 492                  $this->body = $decoded;
 493                  return;
 494              }
 495          }
 496      }
 497  
 498      /**
 499       * Prepare headers (take care of proxies headers)
 500       *
 501       * @param string  $headers Raw headers
 502       * @param integer $count   Redirection count. Default to 1.
 503       *
 504       * @return string
 505       */
 506  	static public function prepareHeaders($headers, $count = 1)
 507      {
 508          $data = explode("\r\n\r\n", $headers, $count);
 509          $data = array_pop($data);
 510          if (false !== stripos($data, "HTTP/1.0 200 Connection established\r\n")) {
 511              $exploded = explode("\r\n\r\n", $data, 2);
 512              $data = end($exploded);
 513          }
 514          if (false !== stripos($data, "HTTP/1.1 200 Connection established\r\n")) {
 515              $exploded = explode("\r\n\r\n", $data, 2);
 516              $data = end($exploded);
 517          }
 518          return $data;
 519      }
 520  }