File indexing completed on 2024-05-12 06:02:05

 <?php
 
 /**
  * Our in-house implementation of a parser.
  *
  * A pure PHP parser, DirectLex has absolutely no dependencies, making
  * it a reasonably good default for PHP4.  Written with efficiency in mind,
  * it can be four times faster than HTMLPurifier_Lexer_PEARSax3, although it
  * pales in comparison to HTMLPurifier_Lexer_DOMLex.
  *
  * @todo Reread XML spec and document differences.
  */
 class HTMLPurifier_Lexer_DirectLex extends HTMLPurifier_Lexer
 {
     /**
      * @type bool
      */
     public $tracksLineNumbers = true;
 
     /**
      * Whitespace characters for str(c)spn.
      * @type string
      */
     protected $_whitespace = "\x20\x09\x0D\x0A";
 
     /**
      * Callback function for script CDATA fudge
      * @param array $matches, in form of array(opening tag, contents, closing tag)
      * @return string
      */
     protected function scriptCallback($matches)
     {
         return $matches[1] . htmlspecialchars($matches[2], ENT_COMPAT, 'UTF-8') . $matches[3];
     }
 
     /**
      * @param String $html
      * @param HTMLPurifier_Config $config
      * @param HTMLPurifier_Context $context
      * @return array|HTMLPurifier_Token[]
      */
     public function tokenizeHTML($html, $config, $context)
     {
         // special normalization for script tags without any armor
         // our "armor" heurstic is a < sign any number of whitespaces after
         // the first script tag
         if ($config->get('HTML.Trusted')) {
             $html = preg_replace_callback(
                 '#(<script[^>]*>)(\s*[^<].+?)(</script>)#si',
                 array($this, 'scriptCallback'),
                 $html
             );
         }
 
         $html = $this->normalize($html, $config, $context);
 
         $cursor = 0; // our location in the text
         $inside_tag = false; // whether or not we're parsing the inside of a tag
         $array = array(); // result array
 
         // This is also treated to mean maintain *column* numbers too
         $maintain_line_numbers = $config->get('Core.MaintainLineNumbers');
 
         if ($maintain_line_numbers === null) {
             // automatically determine line numbering by checking
             // if error collection is on
             $maintain_line_numbers = $config->get('Core.CollectErrors');
         }
 
         if ($maintain_line_numbers) {
             $current_line = 1;
             $current_col = 0;
             $length = strlen($html);
         } else {
             $current_line = false;
             $current_col = false;
             $length = false;
         }
         $context->register('CurrentLine', $current_line);
         $context->register('CurrentCol', $current_col);
         $nl = "\n";
         // how often to manually recalculate. This will ALWAYS be right,
         // but it's pretty wasteful. Set to 0 to turn off
         $synchronize_interval = $config->get('Core.DirectLexLineNumberSyncInterval');
 
         $e = false;
         if ($config->get('Core.CollectErrors')) {
             $e =& $context->get('ErrorCollector');
         }
 
         // for testing synchronization
         $loops = 0;
 
         while (++$loops) {
             // $cursor is either at the start of a token, or inside of
             // a tag (i.e. there was a < immediately before it), as indicated
             // by $inside_tag
 
             if ($maintain_line_numbers) {
                 // $rcursor, however, is always at the start of a token.
                 $rcursor = $cursor - (int)$inside_tag;
 
                 // Column number is cheap, so we calculate it every round.
                 // We're interested at the *end* of the newline string, so
                 // we need to add strlen($nl) == 1 to $nl_pos before subtracting it
                 // from our "rcursor" position.
                 $nl_pos = strrpos($html, $nl, $rcursor - $length);
                 $current_col = $rcursor - (is_bool($nl_pos) ? 0 : $nl_pos + 1);
 
                 // recalculate lines
                 if ($synchronize_interval && // synchronization is on
                     $cursor > 0 && // cursor is further than zero
                     $loops % $synchronize_interval === 0) { // time to synchronize!
                     $current_line = 1 + $this->substrCount($html, $nl, 0, $cursor);
                 }
             }
 
             $position_next_lt = strpos($html, '<', $cursor);
             $position_next_gt = strpos($html, '>', $cursor);
 
             // triggers on "<b>asdf</b>" but not "asdf <b></b>"
             // special case to set up context
             if ($position_next_lt === $cursor) {
                 $inside_tag = true;
                 $cursor++;
             }
 
             if (!$inside_tag && $position_next_lt !== false) {
                 // We are not inside tag and there still is another tag to parse
                 $token = new
                 HTMLPurifier_Token_Text(
                     $this->parseText(
                         substr(
                             $html,
                             $cursor,
                             $position_next_lt - $cursor
                         ), $config
                     )
                 );
                 if ($maintain_line_numbers) {
                     $token->rawPosition($current_line, $current_col);
                     $current_line += $this->substrCount($html, $nl, $cursor, $position_next_lt - $cursor);
                 }
                 $array[] = $token;
                 $cursor = $position_next_lt + 1;
                 $inside_tag = true;
                 continue;
             } elseif (!$inside_tag) {
                 // We are not inside tag but there are no more tags
                 // If we're already at the end, break
                 if ($cursor === strlen($html)) {
                     break;
                 }
                 // Create Text of rest of string
                 $token = new
                 HTMLPurifier_Token_Text(
                     $this->parseText(
                         substr(
                             $html,
                             $cursor
                         ), $config
                     )
                 );
                 if ($maintain_line_numbers) {
                     $token->rawPosition($current_line, $current_col);
                 }
                 $array[] = $token;
                 break;
             } elseif ($inside_tag && $position_next_gt !== false) {
                 // We are in tag and it is well formed
                 // Grab the internals of the tag
                 $strlen_segment = $position_next_gt - $cursor;
 
                 if ($strlen_segment < 1) {
                     // there's nothing to process!
                     $token = new HTMLPurifier_Token_Text('<');
                     $cursor++;
                     continue;
                 }
 
                 $segment = substr($html, $cursor, $strlen_segment);
 
                 if ($segment === false) {
                     // somehow, we attempted to access beyond the end of
                     // the string, defense-in-depth, reported by Nate Abele
                     break;
                 }
 
                 // Check if it's a comment
                 if (substr($segment, 0, 3) === '!--') {
                     // re-determine segment length, looking for -->
                     $position_comment_end = strpos($html, '-->', $cursor);
                     if ($position_comment_end === false) {
                         // uh oh, we have a comment that extends to
                         // infinity. Can't be helped: set comment
                         // end position to end of string
                         if ($e) {
                             $e->send(E_WARNING, 'Lexer: Unclosed comment');
                         }
                         $position_comment_end = strlen($html);
                         $end = true;
                     } else {
                         $end = false;
                     }
                     $strlen_segment = $position_comment_end - $cursor;
                     $segment = substr($html, $cursor, $strlen_segment);
                     $token = new
                     HTMLPurifier_Token_Comment(
                         substr(
                             $segment,
                             3,
                             $strlen_segment - 3
                         )
                     );
                     if ($maintain_line_numbers) {
                         $token->rawPosition($current_line, $current_col);
                         $current_line += $this->substrCount($html, $nl, $cursor, $strlen_segment);
                     }
                     $array[] = $token;
                     $cursor = $end ? $position_comment_end : $position_comment_end + 3;
                     $inside_tag = false;
                     continue;
                 }
 
                 // Check if it's an end tag
                 $is_end_tag = (strpos($segment, '/') === 0);
                 if ($is_end_tag) {
                     $type = substr($segment, 1);
                     $token = new HTMLPurifier_Token_End($type);
                     if ($maintain_line_numbers) {
                         $token->rawPosition($current_line, $current_col);
                         $current_line += $this->substrCount($html, $nl, $cursor, $position_next_gt - $cursor);
                     }
                     $array[] = $token;
                     $inside_tag = false;
                     $cursor = $position_next_gt + 1;
                     continue;
                 }
 
                 // Check leading character is alnum, if not, we may
                 // have accidently grabbed an emoticon. Translate into
                 // text and go our merry way
                 if (!ctype_alpha($segment[0])) {
                     // XML:  $segment[0] !== '_' && $segment[0] !== ':'
                     if ($e) {
                         $e->send(E_NOTICE, 'Lexer: Unescaped lt');
                     }
                     $token = new HTMLPurifier_Token_Text('<');
                     if ($maintain_line_numbers) {
                         $token->rawPosition($current_line, $current_col);
                         $current_line += $this->substrCount($html, $nl, $cursor, $position_next_gt - $cursor);
                     }
                     $array[] = $token;
                     $inside_tag = false;
                     continue;
                 }
 
                 // Check if it is explicitly self closing, if so, remove
                 // trailing slash. Remember, we could have a tag like <br>, so
                 // any later token processing scripts must convert improperly
                 // classified EmptyTags from StartTags.
                 $is_self_closing = (strrpos($segment, '/') === $strlen_segment - 1);
                 if ($is_self_closing) {
                     $strlen_segment--;
                     $segment = substr($segment, 0, $strlen_segment);
                 }
 
                 // Check if there are any attributes
                 $position_first_space = strcspn($segment, $this->_whitespace);
 
                 if ($position_first_space >= $strlen_segment) {
                     if ($is_self_closing) {
                         $token = new HTMLPurifier_Token_Empty($segment);
                     } else {
                         $token = new HTMLPurifier_Token_Start($segment);
                     }
                     if ($maintain_line_numbers) {
                         $token->rawPosition($current_line, $current_col);
                         $current_line += $this->substrCount($html, $nl, $cursor, $position_next_gt - $cursor);
                     }
                     $array[] = $token;
                     $inside_tag = false;
                     $cursor = $position_next_gt + 1;
                     continue;
                 }
 
                 // Grab out all the data
                 $type = substr($segment, 0, $position_first_space);
                 $attribute_string =
                     trim(
                         substr(
                             $segment,
                             $position_first_space
                         )
                     );
                 if ($attribute_string) {
                     $attr = $this->parseAttributeString(
                         $attribute_string,
                         $config,
                         $context
                     );
                 } else {
                     $attr = array();
                 }
 
                 if ($is_self_closing) {
                     $token = new HTMLPurifier_Token_Empty($type, $attr);
                 } else {
                     $token = new HTMLPurifier_Token_Start($type, $attr);
                 }
                 if ($maintain_line_numbers) {
                     $token->rawPosition($current_line, $current_col);
                     $current_line += $this->substrCount($html, $nl, $cursor, $position_next_gt - $cursor);
                 }
                 $array[] = $token;
                 $cursor = $position_next_gt + 1;
                 $inside_tag = false;
                 continue;
             } else {
                 // inside tag, but there's no ending > sign
                 if ($e) {
                     $e->send(E_WARNING, 'Lexer: Missing gt');
                 }
                 $token = new
                 HTMLPurifier_Token_Text(
                     '<' .
                     $this->parseText(
                         substr($html, $cursor), $config
                     )
                 );
                 if ($maintain_line_numbers) {
                     $token->rawPosition($current_line, $current_col);
                 }
                 // no cursor scroll? Hmm...
                 $array[] = $token;
                 break;
             }
             break;
         }
 
         $context->destroy('CurrentLine');
         $context->destroy('CurrentCol');
         return $array;
     }
 
     /**
      * PHP 5.0.x compatible substr_count that implements offset and length
      * @param string $haystack
      * @param string $needle
      * @param int $offset
      * @param int $length
      * @return int
      */
     protected function substrCount($haystack, $needle, $offset, $length)
     {
         static $oldVersion;
         if ($oldVersion === null) {
             $oldVersion = version_compare(PHP_VERSION, '5.1', '<');
         }
         if ($oldVersion) {
             $haystack = substr($haystack, $offset, $length);
             return substr_count($haystack, $needle);
         } else {
             return substr_count($haystack, $needle, $offset, $length);
         }
     }
 
     /**
      * Takes the inside of an HTML tag and makes an assoc array of attributes.
      *
      * @param string $string Inside of tag excluding name.
      * @param HTMLPurifier_Config $config
      * @param HTMLPurifier_Context $context
      * @return array Assoc array of attributes.
      */
     public function parseAttributeString($string, $config, $context)
     {
         $string = (string)$string; // quick typecast
 
         if ($string == '') {
             return array();
         } // no attributes
 
         $e = false;
         if ($config->get('Core.CollectErrors')) {
             $e =& $context->get('ErrorCollector');
         }
 
         // let's see if we can abort as quickly as possible
         // one equal sign, no spaces => one attribute
         $num_equal = substr_count($string, '=');
         $has_space = strpos($string, ' ');
         if ($num_equal === 0 && !$has_space) {
             // bool attribute
             return array($string => $string);
         } elseif ($num_equal === 1 && !$has_space) {
             // only one attribute
             list($key, $quoted_value) = explode('=', $string);
             $quoted_value = trim($quoted_value);
             if (!$key) {
                 if ($e) {
                     $e->send(E_ERROR, 'Lexer: Missing attribute key');
                 }
                 return array();
             }
             if (!$quoted_value) {
                 return array($key => '');
             }
             $first_char = @$quoted_value[0];
             $last_char = @$quoted_value[strlen($quoted_value) - 1];
 
             $same_quote = ($first_char == $last_char);
             $open_quote = ($first_char == '"' || $first_char == "'");
 
             if ($same_quote && $open_quote) {
                 // well behaved
                 $value = substr($quoted_value, 1, strlen($quoted_value) - 2);
             } else {
                 // not well behaved
                 if ($open_quote) {
                     if ($e) {
                         $e->send(E_ERROR, 'Lexer: Missing end quote');
                     }
                     $value = substr($quoted_value, 1);
                 } else {
                     $value = $quoted_value;
                 }
             }
             if ($value === false) {
                 $value = '';
             }
             return array($key => $this->parseAttr($value, $config));
         }
 
         // setup loop environment
         $array = array(); // return assoc array of attributes
         $cursor = 0; // current position in string (moves forward)
         $size = strlen($string); // size of the string (stays the same)
 
         // if we have unquoted attributes, the parser expects a terminating
         // space, so let's guarantee that there's always a terminating space.
         $string .= ' ';
 
         $old_cursor = -1;
         while ($cursor < $size) {
             if ($old_cursor >= $cursor) {
                 throw new Exception("Infinite loop detected");
             }
             $old_cursor = $cursor;
 
             $cursor += ($value = strspn($string, $this->_whitespace, $cursor));
             // grab the key
 
             $key_begin = $cursor; //we're currently at the start of the key
 
             // scroll past all characters that are the key (not whitespace or =)
             $cursor += strcspn($string, $this->_whitespace . '=', $cursor);
 
             $key_end = $cursor; // now at the end of the key
 
             $key = substr($string, $key_begin, $key_end - $key_begin);
 
             if (!$key) {
                 if ($e) {
                     $e->send(E_ERROR, 'Lexer: Missing attribute key');
                 }
                 $cursor += 1 + strcspn($string, $this->_whitespace, $cursor + 1); // prevent infinite loop
                 continue; // empty key
             }
 
             // scroll past all whitespace
             $cursor += strspn($string, $this->_whitespace, $cursor);
 
             if ($cursor >= $size) {
                 $array[$key] = $key;
                 break;
             }
 
             // if the next character is an equal sign, we've got a regular
             // pair, otherwise, it's a bool attribute
             $first_char = @$string[$cursor];
 
             if ($first_char == '=') {
                 // key="value"
 
                 $cursor++;
                 $cursor += strspn($string, $this->_whitespace, $cursor);
 
                 if ($cursor === false) {
                     $array[$key] = '';
                     break;
                 }
 
                 // we might be in front of a quote right now
 
                 $char = @$string[$cursor];
 
                 if ($char == '"' || $char == "'") {
                     // it's quoted, end bound is $char
                     $cursor++;
                     $value_begin = $cursor;
                     $cursor = strpos($string, $char, $cursor);
                     $value_end = $cursor;
                 } else {
                     // it's not quoted, end bound is whitespace
                     $value_begin = $cursor;
                     $cursor += strcspn($string, $this->_whitespace, $cursor);
                     $value_end = $cursor;
                 }
 
                 // we reached a premature end
                 if ($cursor === false) {
                     $cursor = $size;
                     $value_end = $cursor;
                 }
 
                 $value = substr($string, $value_begin, $value_end - $value_begin);
                 if ($value === false) {
                     $value = '';
                 }
                 $array[$key] = $this->parseAttr($value, $config);
                 $cursor++;
             } else {
                 // boolattr
                 if ($key !== '') {
                     $array[$key] = $key;
                 } else {
                     // purely theoretical
                     if ($e) {
                         $e->send(E_ERROR, 'Lexer: Missing attribute key');
                     }
                 }
             }
         }
         return $array;
     }
 }
 
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