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Diffstat (limited to 'framework/Vendor/SafeHtml/TSafeHtmlParser.php')
| -rw-r--r-- | framework/Vendor/SafeHtml/TSafeHtmlParser.php | 685 |
1 files changed, 685 insertions, 0 deletions
diff --git a/framework/Vendor/SafeHtml/TSafeHtmlParser.php b/framework/Vendor/SafeHtml/TSafeHtmlParser.php new file mode 100644 index 00000000..2c01bde2 --- /dev/null +++ b/framework/Vendor/SafeHtml/TSafeHtmlParser.php @@ -0,0 +1,685 @@ +<?php +/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */ + +/** + * SafeHTML Parser + * + * PHP versions 4 and 5 + * + * @category HTML + * @package System.Security + * @author Roman Ivanov <thingol@mail.ru> + * @copyright 2004-2005 Roman Ivanov + * @license http://www.debian.org/misc/bsd.license BSD License (3 Clause) + * @version 1.3.7 + * @link http://pixel-apes.com/safehtml/ + */ + + +/** + * This package requires HTMLSax3 package + */ +Prado::using('System.Vendor.SafeHtml.HTMLSax3'); + + +/** + * + * TSafeHtmlParser + * + * This parser strips down all potentially dangerous content within HTML: + * <ul> + * <li>opening tag without its closing tag</li> + * <li>closing tag without its opening tag</li> + * <li>any of these tags: "base", "basefont", "head", "html", "body", "applet", + * "object", "iframe", "frame", "frameset", "script", "layer", "ilayer", "embed", + * "bgsound", "link", "meta", "style", "title", "blink", "xml" etc.</li> + * <li>any of these attributes: on*, data*, dynsrc</li> + * <li>javascript:/vbscript:/about: etc. protocols</li> + * <li>expression/behavior etc. in styles</li> + * <li>any other active content</li> + * </ul> + * It also tries to convert code to XHTML valid, but htmltidy is far better + * solution for this task. + * + * <b>Example:</b> + * <pre> + * $parser = Prado::createComponent('System.Vendor.SafeHtml.TSafeHtmlParser'); + * $result = $parser->parse($doc); + * </pre> + * + * @category HTML + * @package System.Security + * @author Roman Ivanov <thingol@mail.ru> + * @copyright 1997-2005 Roman Ivanov + * @license http://www.debian.org/misc/bsd.license BSD License (3 Clause) + * @version Release: @package_version@ + * @link http://pear.php.net/package/SafeHTML + */ +class TSafeHtmlParser +{ + /** + * Storage for resulting HTML output + * + * @var string + * @access private + */ + private $_xhtml = ''; + + /** + * Array of counters for each tag + * + * @var array + * @access private + */ + private $_counter = array(); + + /** + * Stack of unclosed tags + * + * @var array + * @access private + */ + private $_stack = array(); + + /** + * Array of counters for tags that must be deleted with all content + * + * @var array + * @access private + */ + private $_dcCounter = array(); + + /** + * Stack of unclosed tags that must be deleted with all content + * + * @var array + * @access private + */ + private $_dcStack = array(); + + /** + * Stores level of list (ol/ul) nesting + * + * @var int + * @access private + */ + private $_listScope = 0; + + /** + * Stack of unclosed list tags + * + * @var array + * @access private + */ + private $_liStack = array(); + + /** + * Array of prepared regular expressions for protocols (schemas) matching + * + * @var array + * @access private + */ + private $_protoRegexps = array(); + + /** + * Array of prepared regular expressions for CSS matching + * + * @var array + * @access private + */ + private $_cssRegexps = array(); + + /** + * List of single tags ("<tag />") + * + * @var array + * @access public + */ + public $singleTags = array('area', 'br', 'img', 'input', 'hr', 'wbr', ); + + /** + * List of dangerous tags (such tags will be deleted) + * + * @var array + * @access public + */ + public $deleteTags = array( + 'applet', 'base', 'basefont', 'bgsound', 'blink', 'body', + 'embed', 'frame', 'frameset', 'head', 'html', 'ilayer', + 'iframe', 'layer', 'link', 'meta', 'object', 'style', + 'title', 'script', + ); + + /** + * List of dangerous tags (such tags will be deleted, and all content + * inside this tags will be also removed) + * + * @var array + * @access public + */ + public $deleteTagsContent = array('script', 'style', 'title', 'xml', ); + + /** + * Type of protocols filtering ('white' or 'black') + * + * @var string + * @access public + */ + public $protocolFiltering = 'white'; + + /** + * List of "dangerous" protocols (used for blacklist-filtering) + * + * @var array + * @access public + */ + public $blackProtocols = array( + 'about', 'chrome', 'data', 'disk', 'hcp', + 'help', 'javascript', 'livescript', 'lynxcgi', 'lynxexec', + 'ms-help', 'ms-its', 'mhtml', 'mocha', 'opera', + 'res', 'resource', 'shell', 'vbscript', 'view-source', + 'vnd.ms.radio', 'wysiwyg', + ); + + /** + * List of "safe" protocols (used for whitelist-filtering) + * + * @var array + * @access public + */ + public $whiteProtocols = array( + 'ed2k', 'file', 'ftp', 'gopher', 'http', 'https', + 'irc', 'mailto', 'news', 'nntp', 'telnet', 'webcal', + 'xmpp', 'callto', + ); + + /** + * List of attributes that can contain protocols + * + * @var array + * @access public + */ + public $protocolAttributes = array( + 'action', 'background', 'codebase', 'dynsrc', 'href', 'lowsrc', 'src', + ); + + /** + * List of dangerous CSS keywords + * + * Whole style="" attribute will be removed, if parser will find one of + * these keywords + * + * @var array + * @access public + */ + public $cssKeywords = array( + 'absolute', 'behavior', 'behaviour', 'content', 'expression', + 'fixed', 'include-source', 'moz-binding', + ); + + /** + * List of tags that can have no "closing tag" + * + * @var array + * @access public + * @deprecated XHTML does not allow such tags + */ + public $noClose = array(); + + /** + * List of block-level tags that terminates paragraph + * + * Paragraph will be closed when this tags opened + * + * @var array + * @access public + */ + public $closeParagraph = array( + 'address', 'blockquote', 'center', 'dd', 'dir', 'div', + 'dl', 'dt', 'h1', 'h2', 'h3', 'h4', + 'h5', 'h6', 'hr', 'isindex', 'listing', 'marquee', + 'menu', 'multicol', 'ol', 'p', 'plaintext', 'pre', + 'table', 'ul', 'xmp', + ); + + /** + * List of table tags, all table tags outside a table will be removed + * + * @var array + * @access public + */ + public $tableTags = array( + 'caption', 'col', 'colgroup', 'tbody', 'td', 'tfoot', 'th', + 'thead', 'tr', + ); + + /** + * List of list tags + * + * @var array + * @access public + */ + public $listTags = array('dir', 'menu', 'ol', 'ul', 'dl', ); + + /** + * List of dangerous attributes + * + * @var array + * @access public + */ + public $attributes = array('dynsrc'); + //public $attributes = array('dynsrc', 'id', 'name', ); //id and name are dangerous? + + /** + * List of allowed "namespaced" attributes + * + * @var array + * @access public + */ + public $attributesNS = array('xml:lang', ); + + /** + * Constructs class + * + * @access public + */ + public function __construct() + { + //making regular expressions based on Proto & CSS arrays + foreach ($this->blackProtocols as $proto) { + $preg = "/[\s\x01-\x1F]*"; + for ($i=0; $i<strlen($proto); $i++) { + $preg .= $proto{$i} . "[\s\x01-\x1F]*"; + } + $preg .= ":/i"; + $this->_protoRegexps[] = $preg; + } + + foreach ($this->cssKeywords as $css) { + $this->_cssRegexps[] = '/' . $css . '/i'; + } + return true; + } + + /** + * Handles the writing of attributes - called from $this->_openHandler() + * + * @param array $attrs array of attributes $name => $value + * @return boolean + * @access private + */ + private function _writeAttrs ($attrs) + { + if (is_array($attrs)) { + foreach ($attrs as $name => $value) { + + $name = strtolower($name); + + if (strpos($name, 'on') === 0) { + continue; + } + if (strpos($name, 'data') === 0) { + continue; + } + if (in_array($name, $this->attributes)) { + continue; + } + if (!preg_match("/^[a-z0-9]+$/i", $name)) { + if (!in_array($name, $this->attributesNS)) + { + continue; + } + } + + if (($value === TRUE) || (is_null($value))) { + $value = $name; + } + + if ($name == 'style') { + + // removes insignificant backslahes + $value = str_replace("\\", '', $value); + + // removes CSS comments + while (1) + { + $_value = preg_replace("!/\*.*?\*/!s", '', $value); + if ($_value == $value) break; + $value = $_value; + } + + // replace all & to & + $value = str_replace('&', '&', $value); + $value = str_replace('&', '&', $value); + + foreach ($this->_cssRegexps as $css) { + if (preg_match($css, $value)) { + continue 2; + } + } + foreach ($this->_protoRegexps as $proto) { + if (preg_match($proto, $value)) { + continue 2; + } + } + } + + $tempval = preg_replace_callback( + '/&#(\d+);?/m', + function ($matches) { + return chr($matches[0]); + }, + $value + ); //"' + + $tempval = preg_replace_callback( + '/&#x([0-9a-f]+);?/mi', + function ($matches) { + return chr(hexdec($matches[0])); + }, + $tempval + ); + + if ((in_array($name, $this->protocolAttributes)) && + (strpos($tempval, ':') !== false)) + { + if ($this->protocolFiltering == 'black') { + foreach ($this->_protoRegexps as $proto) { + if (preg_match($proto, $tempval)) continue 2; + } + } else { + $_tempval = explode(':', $tempval); + $proto = $_tempval[0]; + if (!in_array($proto, $this->whiteProtocols)) { + continue; + } + } + } + + $value = str_replace("\"", """, $value); + $this->_xhtml .= ' ' . $name . '="' . $value . '"'; + } + } + return true; + } + + /** + * Opening tag handler - called from HTMLSax + * + * @param object $parser HTML Parser + * @param string $name tag name + * @param array $attrs tag attributes + * @return boolean + * @access private + */ + public function _openHandler(&$parser, $name, $attrs) + { + $name = strtolower($name); + + if (in_array($name, $this->deleteTagsContent)) { + array_push($this->_dcStack, $name); + $this->_dcCounter[$name] = isset($this->_dcCounter[$name]) ? $this->_dcCounter[$name]+1 : 1; + } + if (count($this->_dcStack) != 0) { + return true; + } + + if (in_array($name, $this->deleteTags)) { + return true; + } + + if (!preg_match("/^[a-z0-9]+$/i", $name)) { + if (preg_match("!(?:\@|://)!i", $name)) { + $this->_xhtml .= '<' . $name . '>'; + } + return true; + } + + if (in_array($name, $this->singleTags)) { + $this->_xhtml .= '<' . $name; + $this->_writeAttrs($attrs); + $this->_xhtml .= ' />'; + return true; + } + + // TABLES: cannot open table elements when we are not inside table + if ((isset($this->_counter['table'])) && ($this->_counter['table'] <= 0) + && (in_array($name, $this->tableTags))) + { + return true; + } + + // PARAGRAPHS: close paragraph when closeParagraph tags opening + if ((in_array($name, $this->closeParagraph)) && (in_array('p', $this->_stack))) { + $this->_closeHandler($parser, 'p'); + } + + // LISTS: we should close <li> if <li> of the same level opening + if ($name == 'li' && count($this->_liStack) && + $this->_listScope == $this->_liStack[count($this->_liStack)-1]) + { + $this->_closeHandler($parser, 'li'); + } + + // LISTS: we want to know on what nesting level of lists we are + if (in_array($name, $this->listTags)) { + $this->_listScope++; + } + if ($name == 'li') { + array_push($this->_liStack, $this->_listScope); + } + + $this->_xhtml .= '<' . $name; + $this->_writeAttrs($attrs); + $this->_xhtml .= '>'; + array_push($this->_stack,$name); + $this->_counter[$name] = isset($this->_counter[$name]) ? $this->_counter[$name]+1 : 1; + return true; + } + + /** + * Closing tag handler - called from HTMLSax + * + * @param object $parsers HTML parser + * @param string $name tag name + * @return boolean + * @access private + */ + public function _closeHandler(&$parser, $name) + { + + $name = strtolower($name); + + if (isset($this->_dcCounter[$name]) && ($this->_dcCounter[$name] > 0) && + (in_array($name, $this->deleteTagsContent))) + { + while ($name != ($tag = array_pop($this->_dcStack))) { + $this->_dcCounter[$tag]--; + } + + $this->_dcCounter[$name]--; + } + + if (count($this->_dcStack) != 0) { + return true; + } + + if ((isset($this->_counter[$name])) && ($this->_counter[$name] > 0)) { + while ($name != ($tag = array_pop($this->_stack))) { + $this->_closeTag($tag); + } + + $this->_closeTag($name); + } + return true; + } + + /** + * Closes tag + * + * @param string $tag tag name + * @return boolean + * @access private + */ + public function _closeTag($tag) + { + if (!in_array($tag, $this->noClose)) { + $this->_xhtml .= '</' . $tag . '>'; + } + + $this->_counter[$tag]--; + + if (in_array($tag, $this->listTags)) { + $this->_listScope--; + } + + if ($tag == 'li') { + array_pop($this->_liStack); + } + return true; + } + + /** + * Character data handler - called from HTMLSax + * + * @param object $parser HTML parser + * @param string $data textual data + * @return boolean + * @access private + */ + public function _dataHandler(&$parser, $data) + { + if (count($this->_dcStack) == 0) { + $this->_xhtml .= $data; + } + return true; + } + + /** + * Escape handler - called from HTMLSax + * + * @param object $parser HTML parser + * @param string $data comments or other type of data + * @return boolean + * @access private + */ + public function _escapeHandler(&$parser, $data) + { + return true; + } + + /** + * Returns the XHTML document + * + * @return string Processed (X)HTML document + * @access public + */ + public function getXHTML () + { + while ($tag = array_pop($this->_stack)) { + $this->_closeTag($tag); + } + + return $this->_xhtml; + } + + /** + * Clears current document data + * + * @return boolean + * @access public + */ + public function clear() + { + $this->_xhtml = ''; + return true; + } + + /** + * Main parsing fuction + * + * @param string $doc HTML document for processing + * @return string Processed (X)HTML document + * @access public + */ + public function parse($doc, $isUTF7=false) + { + $this->clear(); + + // Save all '<' symbols + $doc = preg_replace("/<(?=[^a-zA-Z\/\!\?\%])/", '<', (string)$doc); + + // Web documents shouldn't contains \x00 symbol + $doc = str_replace("\x00", '', $doc); + + // Opera6 bug workaround + $doc = str_replace("\xC0\xBC", '<', $doc); + + // UTF-7 encoding ASCII decode + if($isUTF7) + $doc = $this->repackUTF7($doc); + + // Instantiate the parser + $parser= new TSax3(); + + // Set up the parser + $parser->set_object($this); + + $parser->set_element_handler('_openHandler','_closeHandler'); + $parser->set_data_handler('_dataHandler'); + $parser->set_escape_handler('_escapeHandler'); + + $parser->parse($doc); + + return $this->getXHTML(); + + } + + + /** + * UTF-7 decoding fuction + * + * @param string $str HTML document for recode ASCII part of UTF-7 back to ASCII + * @return string Decoded document + * @access private + */ + private function repackUTF7($str) + { + return preg_replace_callback('!\+([0-9a-zA-Z/]+)\-!', array($this, 'repackUTF7Callback'), $str); + } + + /** + * Additional UTF-7 decoding fuction + * + * @param string $str String for recode ASCII part of UTF-7 back to ASCII + * @return string Recoded string + * @access private + */ + private function repackUTF7Callback($str) + { + $str = base64_decode($str[1]); + $str = preg_replace_callback('/^((?:\x00.)*)((?:[^\x00].)+)/', array($this, 'repackUTF7Back'), $str); + return preg_replace('/\x00(.)/', '$1', $str); + } + + /** + * Additional UTF-7 encoding fuction + * + * @param string $str String for recode ASCII part of UTF-7 back to ASCII + * @return string Recoded string + * @access private + */ + private function repackUTF7Back($str) + { + return $str[1].'+'.rtrim(base64_encode($str[2]), '=').'-'; + } +} + +/* + * Local variables: + * tab-width: 4 + * c-basic-offset: 4 + * c-hanging-comment-ender-p: nil + * End: + */ + |