filter_xss_bad_protocol
Definition
filter_xss_bad_protocol($string, $decode = TRUE)
drupal/modules/filter.module, line 1227
Description
Processes an HTML attribute value and ensures it does not contain an URL with a disallowed protocol (e.g. javascript:)
Parameters
$string The string with the attribute value.
$decode Whether to decode entities in the $string. Set to FALSE if the $string is in plain text, TRUE otherwise. Defaults to TRUE.
Return value
Cleaned up and HTML-escaped version of $string.
Code
function filter_xss_bad_protocol($string, $decode = TRUE) {
static $allowed_protocols;
if (!isset($allowed_protocols)) {
$allowed_protocols = array_flip(variable_get('filter_allowed_protocols', array('http', 'https', 'ftp', 'news', 'nntp', 'telnet', 'mailto', 'irc', 'ssh', 'sftp', 'webcal')));
}
// Get the plain text representation of the attribute value (i.e. its meaning)
if ($decode) {
$string = decode_entities($string);
}
// Iteratively remove any invalid protocol found.
do {
$before = $string;
$colonpos = strpos($string, ':');
if ($colonpos > 0) {
// We found a colon, possibly a protocol. Verify.
$protocol = substr($string, 0, $colonpos);
// If a colon is preceded by a slash, question mark or hash, it cannot
// possibly be part of the URL scheme. This must be a relative URL,
// which inherits the (safe) protocol of the base document.
if (preg_match('![/?#]!', $protocol)) {
break;
}
// Check if this is a disallowed protocol
if (!isset($allowed_protocols[$protocol])) {
$string = substr($string, $colonpos + 1);
}
}
} while ($before != $string);
return check_plain($string);
}