--- /dev/null
+<?php
+/**
+ * Zend Framework (http://framework.zend.com/)
+ *
+ * @link http://github.com/zendframework/zf2 for the canonical source repository
+ * @copyright Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license http://framework.zend.com/license/new-bsd New BSD License
+ */
+
+namespace Zend\Escaper;
+
+/**
+ * Context specific methods for use in secure output escaping
+ */
+class Escaper
+{
+ /**
+ * Entity Map mapping Unicode codepoints to any available named HTML entities.
+ *
+ * While HTML supports far more named entities, the lowest common denominator
+ * has become HTML5's XML Serialisation which is restricted to the those named
+ * entities that XML supports. Using HTML entities would result in this error:
+ * XML Parsing Error: undefined entity
+ *
+ * @var array
+ */
+ protected static $htmlNamedEntityMap = [
+ 34 => 'quot', // quotation mark
+ 38 => 'amp', // ampersand
+ 60 => 'lt', // less-than sign
+ 62 => 'gt', // greater-than sign
+ ];
+
+ /**
+ * Current encoding for escaping. If not UTF-8, we convert strings from this encoding
+ * pre-escaping and back to this encoding post-escaping.
+ *
+ * @var string
+ */
+ protected $encoding = 'utf-8';
+
+ /**
+ * Holds the value of the special flags passed as second parameter to
+ * htmlspecialchars().
+ *
+ * @var int
+ */
+ protected $htmlSpecialCharsFlags;
+
+ /**
+ * Static Matcher which escapes characters for HTML Attribute contexts
+ *
+ * @var callable
+ */
+ protected $htmlAttrMatcher;
+
+ /**
+ * Static Matcher which escapes characters for Javascript contexts
+ *
+ * @var callable
+ */
+ protected $jsMatcher;
+
+ /**
+ * Static Matcher which escapes characters for CSS Attribute contexts
+ *
+ * @var callable
+ */
+ protected $cssMatcher;
+
+ /**
+ * List of all encoding supported by this class
+ *
+ * @var array
+ */
+ protected $supportedEncodings = [
+ 'iso-8859-1', 'iso8859-1', 'iso-8859-5', 'iso8859-5',
+ 'iso-8859-15', 'iso8859-15', 'utf-8', 'cp866',
+ 'ibm866', '866', 'cp1251', 'windows-1251',
+ 'win-1251', '1251', 'cp1252', 'windows-1252',
+ '1252', 'koi8-r', 'koi8-ru', 'koi8r',
+ 'big5', '950', 'gb2312', '936',
+ 'big5-hkscs', 'shift_jis', 'sjis', 'sjis-win',
+ 'cp932', '932', 'euc-jp', 'eucjp',
+ 'eucjp-win', 'macroman'
+ ];
+
+ /**
+ * Constructor: Single parameter allows setting of global encoding for use by
+ * the current object.
+ *
+ * @param string $encoding
+ * @throws Exception\InvalidArgumentException
+ */
+ public function __construct($encoding = null)
+ {
+ if ($encoding !== null) {
+ $encoding = (string) $encoding;
+ if ($encoding === '') {
+ throw new Exception\InvalidArgumentException(
+ get_class($this) . ' constructor parameter does not allow a blank value'
+ );
+ }
+
+ $encoding = strtolower($encoding);
+ if (!in_array($encoding, $this->supportedEncodings)) {
+ throw new Exception\InvalidArgumentException(
+ 'Value of \'' . $encoding . '\' passed to ' . get_class($this)
+ . ' constructor parameter is invalid. Provide an encoding supported by htmlspecialchars()'
+ );
+ }
+
+ $this->encoding = $encoding;
+ }
+
+ // We take advantage of ENT_SUBSTITUTE flag to correctly deal with invalid UTF-8 sequences.
+ $this->htmlSpecialCharsFlags = ENT_QUOTES | ENT_SUBSTITUTE;
+
+ // set matcher callbacks
+ $this->htmlAttrMatcher = [$this, 'htmlAttrMatcher'];
+ $this->jsMatcher = [$this, 'jsMatcher'];
+ $this->cssMatcher = [$this, 'cssMatcher'];
+ }
+
+ /**
+ * Return the encoding that all output/input is expected to be encoded in.
+ *
+ * @return string
+ */
+ public function getEncoding()
+ {
+ return $this->encoding;
+ }
+
+ /**
+ * Escape a string for the HTML Body context where there are very few characters
+ * of special meaning. Internally this will use htmlspecialchars().
+ *
+ * @param string $string
+ * @return string
+ */
+ public function escapeHtml($string)
+ {
+ return htmlspecialchars($string, $this->htmlSpecialCharsFlags, $this->encoding);
+ }
+
+ /**
+ * Escape a string for the HTML Attribute context. We use an extended set of characters
+ * to escape that are not covered by htmlspecialchars() to cover cases where an attribute
+ * might be unquoted or quoted illegally (e.g. backticks are valid quotes for IE).
+ *
+ * @param string $string
+ * @return string
+ */
+ public function escapeHtmlAttr($string)
+ {
+ $string = $this->toUtf8($string);
+ if ($string === '' || ctype_digit($string)) {
+ return $string;
+ }
+
+ $result = preg_replace_callback('/[^a-z0-9,\.\-_]/iSu', $this->htmlAttrMatcher, $string);
+ return $this->fromUtf8($result);
+ }
+
+ /**
+ * Escape a string for the Javascript context. This does not use json_encode(). An extended
+ * set of characters are escaped beyond ECMAScript's rules for Javascript literal string
+ * escaping in order to prevent misinterpretation of Javascript as HTML leading to the
+ * injection of special characters and entities. The escaping used should be tolerant
+ * of cases where HTML escaping was not applied on top of Javascript escaping correctly.
+ * Backslash escaping is not used as it still leaves the escaped character as-is and so
+ * is not useful in a HTML context.
+ *
+ * @param string $string
+ * @return string
+ */
+ public function escapeJs($string)
+ {
+ $string = $this->toUtf8($string);
+ if ($string === '' || ctype_digit($string)) {
+ return $string;
+ }
+
+ $result = preg_replace_callback('/[^a-z0-9,\._]/iSu', $this->jsMatcher, $string);
+ return $this->fromUtf8($result);
+ }
+
+ /**
+ * Escape a string for the URI or Parameter contexts. This should not be used to escape
+ * an entire URI - only a subcomponent being inserted. The function is a simple proxy
+ * to rawurlencode() which now implements RFC 3986 since PHP 5.3 completely.
+ *
+ * @param string $string
+ * @return string
+ */
+ public function escapeUrl($string)
+ {
+ return rawurlencode($string);
+ }
+
+ /**
+ * Escape a string for the CSS context. CSS escaping can be applied to any string being
+ * inserted into CSS and escapes everything except alphanumerics.
+ *
+ * @param string $string
+ * @return string
+ */
+ public function escapeCss($string)
+ {
+ $string = $this->toUtf8($string);
+ if ($string === '' || ctype_digit($string)) {
+ return $string;
+ }
+
+ $result = preg_replace_callback('/[^a-z0-9]/iSu', $this->cssMatcher, $string);
+ return $this->fromUtf8($result);
+ }
+
+ /**
+ * Callback function for preg_replace_callback that applies HTML Attribute
+ * escaping to all matches.
+ *
+ * @param array $matches
+ * @return string
+ */
+ protected function htmlAttrMatcher($matches)
+ {
+ $chr = $matches[0];
+ $ord = ord($chr);
+
+ /**
+ * The following replaces characters undefined in HTML with the
+ * hex entity for the Unicode replacement character.
+ */
+ if (($ord <= 0x1f && $chr != "\t" && $chr != "\n" && $chr != "\r")
+ || ($ord >= 0x7f && $ord <= 0x9f)
+ ) {
+ return '�';
+ }
+
+ /**
+ * Check if the current character to escape has a name entity we should
+ * replace it with while grabbing the integer value of the character.
+ */
+ if (strlen($chr) > 1) {
+ $chr = $this->convertEncoding($chr, 'UTF-32BE', 'UTF-8');
+ }
+
+ $hex = bin2hex($chr);
+ $ord = hexdec($hex);
+ if (isset(static::$htmlNamedEntityMap[$ord])) {
+ return '&' . static::$htmlNamedEntityMap[$ord] . ';';
+ }
+
+ /**
+ * Per OWASP recommendations, we'll use upper hex entities
+ * for any other characters where a named entity does not exist.
+ */
+ if ($ord > 255) {
+ return sprintf('&#x%04X;', $ord);
+ }
+ return sprintf('&#x%02X;', $ord);
+ }
+
+ /**
+ * Callback function for preg_replace_callback that applies Javascript
+ * escaping to all matches.
+ *
+ * @param array $matches
+ * @return string
+ */
+ protected function jsMatcher($matches)
+ {
+ $chr = $matches[0];
+ if (strlen($chr) == 1) {
+ return sprintf('\\x%02X', ord($chr));
+ }
+ $chr = $this->convertEncoding($chr, 'UTF-16BE', 'UTF-8');
+ $hex = strtoupper(bin2hex($chr));
+ if (strlen($hex) <= 4) {
+ return sprintf('\\u%04s', $hex);
+ }
+ $highSurrogate = substr($hex, 0, 4);
+ $lowSurrogate = substr($hex, 4, 4);
+ return sprintf('\\u%04s\\u%04s', $highSurrogate, $lowSurrogate);
+ }
+
+ /**
+ * Callback function for preg_replace_callback that applies CSS
+ * escaping to all matches.
+ *
+ * @param array $matches
+ * @return string
+ */
+ protected function cssMatcher($matches)
+ {
+ $chr = $matches[0];
+ if (strlen($chr) == 1) {
+ $ord = ord($chr);
+ } else {
+ $chr = $this->convertEncoding($chr, 'UTF-32BE', 'UTF-8');
+ $ord = hexdec(bin2hex($chr));
+ }
+ return sprintf('\\%X ', $ord);
+ }
+
+ /**
+ * Converts a string to UTF-8 from the base encoding. The base encoding is set via this
+ * class' constructor.
+ *
+ * @param string $string
+ * @throws Exception\RuntimeException
+ * @return string
+ */
+ protected function toUtf8($string)
+ {
+ if ($this->getEncoding() === 'utf-8') {
+ $result = $string;
+ } else {
+ $result = $this->convertEncoding($string, 'UTF-8', $this->getEncoding());
+ }
+
+ if (!$this->isUtf8($result)) {
+ throw new Exception\RuntimeException(
+ sprintf('String to be escaped was not valid UTF-8 or could not be converted: %s', $result)
+ );
+ }
+
+ return $result;
+ }
+
+ /**
+ * Converts a string from UTF-8 to the base encoding. The base encoding is set via this
+ * class' constructor.
+ * @param string $string
+ * @return string
+ */
+ protected function fromUtf8($string)
+ {
+ if ($this->getEncoding() === 'utf-8') {
+ return $string;
+ }
+
+ return $this->convertEncoding($string, $this->getEncoding(), 'UTF-8');
+ }
+
+ /**
+ * Checks if a given string appears to be valid UTF-8 or not.
+ *
+ * @param string $string
+ * @return bool
+ */
+ protected function isUtf8($string)
+ {
+ return ($string === '' || preg_match('/^./su', $string));
+ }
+
+ /**
+ * Encoding conversion helper which wraps iconv and mbstring where they exist or throws
+ * and exception where neither is available.
+ *
+ * @param string $string
+ * @param string $to
+ * @param array|string $from
+ * @throws Exception\RuntimeException
+ * @return string
+ */
+ protected function convertEncoding($string, $to, $from)
+ {
+ if (function_exists('iconv')) {
+ $result = iconv($from, $to, $string);
+ } elseif (function_exists('mb_convert_encoding')) {
+ $result = mb_convert_encoding($string, $to, $from);
+ } else {
+ throw new Exception\RuntimeException(
+ get_class($this)
+ . ' requires either the iconv or mbstring extension to be installed'
+ . ' when escaping for non UTF-8 strings.'
+ );
+ }
+
+ if ($result === false) {
+ return ''; // return non-fatal blank string on encoding errors from users
+ }
+ return $result;
+ }
+}
projects / yaffs-website / blobdiff