wp-includes/SimplePie/HTTP/Parser.php

   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) 2004-2012, Ryan Parman, Geoffrey 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  * @version 1.3.1
  37  * @copyright 2004-2012 Ryan Parman, Geoffrey Sneddon, Ryan McCue
  38  * @author Ryan Parman
  39  * @author Geoffrey Sneddon
  40  * @author Ryan McCue
  41  * @link http://simplepie.org/ SimplePie
  42  * @license http://www.opensource.org/licenses/bsd-license.php BSD License
  43  */
  44
  45
  46 /**
  47  * HTTP Response Parser
  48  *
  49  * @package SimplePie
  50  * @subpackage HTTP
  51  */
  52 class SimplePie_HTTP_Parser
  53 {
  54         /**
  55          * HTTP Version
  56          *
  57          * @var float
  58          */
  59         public $http_version = 0.0;
  60
  61         /**
  62          * Status code
  63          *
  64          * @var int
  65          */
  66         public $status_code = 0;
  67
  68         /**
  69          * Reason phrase
  70          *
  71          * @var string
  72          */
  73         public $reason = '';
  74
  75         /**
  76          * Key/value pairs of the headers
  77          *
  78          * @var array
  79          */
  80         public $headers = array();
  81
  82         /**
  83          * Body of the response
  84          *
  85          * @var string
  86          */
  87         public $body = '';
  88
  89         /**
  90          * Current state of the state machine
  91          *
  92          * @var string
  93          */
  94         protected $state = 'http_version';
  95
  96         /**
  97          * Input data
  98          *
  99          * @var string
 100          */
 101         protected $data = '';
 102
 103         /**
 104          * Input data length (to avoid calling strlen() everytime this is needed)
 105          *
 106          * @var int
 107          */
 108         protected $data_length = 0;
 109
 110         /**
 111          * Current position of the pointer
 112          *
 113          * @var int
 114          */
 115         protected $position = 0;
 116
 117         /**
 118          * Name of the hedaer currently being parsed
 119          *
 120          * @var string
 121          */
 122         protected $name = '';
 123
 124         /**
 125          * Value of the hedaer currently being parsed
 126          *
 127          * @var string
 128          */
 129         protected $value = '';
 130
 131         /**
 132          * Create an instance of the class with the input data
 133          *
 134          * @param string $data Input data
 135          */
 136         public function __construct($data)
 137         {
 138                 $this->data = $data;
 139                 $this->data_length = strlen($this->data);
 140         }
 141
 142         /**
 143          * Parse the input data
 144          *
 145          * @return bool true on success, false on failure
 146          */
 147         public function parse()
 148         {
 149                 while ($this->state && $this->state !== 'emit' && $this->has_data())
 150                 {
 151                         $state = $this->state;
 152                         $this->$state();
 153                 }
 154                 $this->data = '';
 155                 if ($this->state === 'emit' || $this->state === 'body')
 156                 {
 157                         return true;
 158                 }
 159                 else
 160                 {
 161                         $this->http_version = '';
 162                         $this->status_code = '';
 163                         $this->reason = '';
 164                         $this->headers = array();
 165                         $this->body = '';
 166                         return false;
 167                 }
 168         }
 169
 170         /**
 171          * Check whether there is data beyond the pointer
 172          *
 173          * @return bool true if there is further data, false if not
 174          */
 175         protected function has_data()
 176         {
 177                 return (bool) ($this->position < $this->data_length);
 178         }
 179
 180         /**
 181          * See if the next character is LWS
 182          *
 183          * @return bool true if the next character is LWS, false if not
 184          */
 185         protected function is_linear_whitespace()
 186         {
 187                 return (bool) ($this->data[$this->position] === "\x09"
 188                         || $this->data[$this->position] === "\x20"
 189                         || ($this->data[$this->position] === "\x0A"
 190                                 && isset($this->data[$this->position + 1])
 191                                 && ($this->data[$this->position + 1] === "\x09" || $this->data[$this->position + 1] === "\x20")));
 192         }
 193
 194         /**
 195          * Parse the HTTP version
 196          */
 197         protected function http_version()
 198         {
 199                 if (strpos($this->data, "\x0A") !== false && strtoupper(substr($this->data, 0, 5)) === 'HTTP/')
 200                 {
 201                         $len = strspn($this->data, '0123456789.', 5);
 202                         $this->http_version = substr($this->data, 5, $len);
 203                         $this->position += 5 + $len;
 204                         if (substr_count($this->http_version, '.') <= 1)
 205                         {
 206                                 $this->http_version = (float) $this->http_version;
 207                                 $this->position += strspn($this->data, "\x09\x20", $this->position);
 208                                 $this->state = 'status';
 209                         }
 210                         else
 211                         {
 212                                 $this->state = false;
 213                         }
 214                 }
 215                 else
 216                 {
 217                         $this->state = false;
 218                 }
 219         }
 220
 221         /**
 222          * Parse the status code
 223          */
 224         protected function status()
 225         {
 226                 if ($len = strspn($this->data, '0123456789', $this->position))
 227                 {
 228                         $this->status_code = (int) substr($this->data, $this->position, $len);
 229                         $this->position += $len;
 230                         $this->state = 'reason';
 231                 }
 232                 else
 233                 {
 234                         $this->state = false;
 235                 }
 236         }
 237
 238         /**
 239          * Parse the reason phrase
 240          */
 241         protected function reason()
 242         {
 243                 $len = strcspn($this->data, "\x0A", $this->position);
 244                 $this->reason = trim(substr($this->data, $this->position, $len), "\x09\x0D\x20");
 245                 $this->position += $len + 1;
 246                 $this->state = 'new_line';
 247         }
 248
 249         /**
 250          * Deal with a new line, shifting data around as needed
 251          */
 252         protected function new_line()
 253         {
 254                 $this->value = trim($this->value, "\x0D\x20");
 255                 if ($this->name !== '' && $this->value !== '')
 256                 {
 257                         $this->name = strtolower($this->name);
 258                         // We should only use the last Content-Type header. c.f. issue #1
 259                         if (isset($this->headers[$this->name]) && $this->name !== 'content-type')
 260                         {
 261                                 $this->headers[$this->name] .= ', ' . $this->value;
 262                         }
 263                         else
 264                         {
 265                                 $this->headers[$this->name] = $this->value;
 266                         }
 267                 }
 268                 $this->name = '';
 269                 $this->value = '';
 270                 if (substr($this->data[$this->position], 0, 2) === "\x0D\x0A")
 271                 {
 272                         $this->position += 2;
 273                         $this->state = 'body';
 274                 }
 275                 elseif ($this->data[$this->position] === "\x0A")
 276                 {
 277                         $this->position++;
 278                         $this->state = 'body';
 279                 }
 280                 else
 281                 {
 282                         $this->state = 'name';
 283                 }
 284         }
 285
 286         /**
 287          * Parse a header name
 288          */
 289         protected function name()
 290         {
 291                 $len = strcspn($this->data, "\x0A:", $this->position);
 292                 if (isset($this->data[$this->position + $len]))
 293                 {
 294                         if ($this->data[$this->position + $len] === "\x0A")
 295                         {
 296                                 $this->position += $len;
 297                                 $this->state = 'new_line';
 298                         }
 299                         else
 300                         {
 301                                 $this->name = substr($this->data, $this->position, $len);
 302                                 $this->position += $len + 1;
 303                                 $this->state = 'value';
 304                         }
 305                 }
 306                 else
 307                 {
 308                         $this->state = false;
 309                 }
 310         }
 311
 312         /**
 313          * Parse LWS, replacing consecutive LWS characters with a single space
 314          */
 315         protected function linear_whitespace()
 316         {
 317                 do
 318                 {
 319                         if (substr($this->data, $this->position, 2) === "\x0D\x0A")
 320                         {
 321                                 $this->position += 2;
 322                         }
 323                         elseif ($this->data[$this->position] === "\x0A")
 324                         {
 325                                 $this->position++;
 326                         }
 327                         $this->position += strspn($this->data, "\x09\x20", $this->position);
 328                 } while ($this->has_data() && $this->is_linear_whitespace());
 329                 $this->value .= "\x20";
 330         }
 331
 332         /**
 333          * See what state to move to while within non-quoted header values
 334          */
 335         protected function value()
 336         {
 337                 if ($this->is_linear_whitespace())
 338                 {
 339                         $this->linear_whitespace();
 340                 }
 341                 else
 342                 {
 343                         switch ($this->data[$this->position])
 344                         {
 345                                 case '"':
 346                                         // Workaround for ETags: we have to include the quotes as
 347                                         // part of the tag.
 348                                         if (strtolower($this->name) === 'etag')
 349                                         {
 350                                                 $this->value .= '"';
 351                                                 $this->position++;
 352                                                 $this->state = 'value_char';
 353                                                 break;
 354                                         }
 355                                         $this->position++;
 356                                         $this->state = 'quote';
 357                                         break;
 358
 359                                 case "\x0A":
 360                                         $this->position++;
 361                                         $this->state = 'new_line';
 362                                         break;
 363
 364                                 default:
 365                                         $this->state = 'value_char';
 366                                         break;
 367                         }
 368                 }
 369         }
 370
 371         /**
 372          * Parse a header value while outside quotes
 373          */
 374         protected function value_char()
 375         {
 376                 $len = strcspn($this->data, "\x09\x20\x0A\"", $this->position);
 377                 $this->value .= substr($this->data, $this->position, $len);
 378                 $this->position += $len;
 379                 $this->state = 'value';
 380         }
 381
 382         /**
 383          * See what state to move to while within quoted header values
 384          */
 385         protected function quote()
 386         {
 387                 if ($this->is_linear_whitespace())
 388                 {
 389                         $this->linear_whitespace();
 390                 }
 391                 else
 392                 {
 393                         switch ($this->data[$this->position])
 394                         {
 395                                 case '"':
 396                                         $this->position++;
 397                                         $this->state = 'value';
 398                                         break;
 399
 400                                 case "\x0A":
 401                                         $this->position++;
 402                                         $this->state = 'new_line';
 403                                         break;
 404
 405                                 case '\\':
 406                                         $this->position++;
 407                                         $this->state = 'quote_escaped';
 408                                         break;
 409
 410                                 default:
 411                                         $this->state = 'quote_char';
 412                                         break;
 413                         }
 414                 }
 415         }
 416
 417         /**
 418          * Parse a header value while within quotes
 419          */
 420         protected function quote_char()
 421         {
 422                 $len = strcspn($this->data, "\x09\x20\x0A\"\\", $this->position);
 423                 $this->value .= substr($this->data, $this->position, $len);
 424                 $this->position += $len;
 425                 $this->state = 'value';
 426         }
 427
 428         /**
 429          * Parse an escaped character within quotes
 430          */
 431         protected function quote_escaped()
 432         {
 433                 $this->value .= $this->data[$this->position];
 434                 $this->position++;
 435                 $this->state = 'quote';
 436         }
 437
 438         /**
 439          * Parse the body
 440          */
 441         protected function body()
 442         {
 443                 $this->body = substr($this->data, $this->position);
 444                 if (!empty($this->headers['transfer-encoding']))
 445                 {
 446                         unset($this->headers['transfer-encoding']);
 447                         $this->state = 'chunked';
 448                 }
 449                 else
 450                 {
 451                         $this->state = 'emit';
 452                 }
 453         }
 454
 455         /**
 456          * Parsed a "Transfer-Encoding: chunked" body
 457          */
 458         protected function chunked()
 459         {
 460                 if (!preg_match('/^([0-9a-f]+)[^\r\n]*\r\n/i', trim($this->body)))
 461                 {
 462                         $this->state = 'emit';
 463                         return;
 464                 }
 465
 466                 $decoded = '';
 467                 $encoded = $this->body;
 468
 469                 while (true)
 470                 {
 471                         $is_chunked = (bool) preg_match( '/^([0-9a-f]+)[^\r\n]*\r\n/i', $encoded, $matches );
 472                         if (!$is_chunked)
 473                         {
 474                                 // Looks like it's not chunked after all
 475                                 $this->state = 'emit';
 476                                 return;
 477                         }
 478
 479                         $length = hexdec(trim($matches[1]));
 480                         if ($length === 0)
 481                         {
 482                                 // Ignore trailer headers
 483                                 $this->state = 'emit';
 484                                 $this->body = $decoded;
 485                                 return;
 486                         }
 487
 488                         $chunk_length = strlen($matches[0]);
 489                         $decoded .= $part = substr($encoded, $chunk_length, $length);
 490                         $encoded = substr($encoded, $chunk_length + $length + 2);
 491
 492                         if (trim($encoded) === '0' || empty($encoded))
 493                         {
 494                                 $this->state = 'emit';
 495                                 $this->body = $decoded;
 496                                 return;
 497                         }
 498                 }
 499         }
 500 }