/**
* Returns the supplied input string after removing any characters not
* present in the supplied whitelist.
*
* @param string $input string input to be filtered.
* @param string $whitelist array or string of whitelist characters.
*
* @return string returns characters from $input that are present in $whitelist.
*/
public function whitelist($input, $whitelist)
{
// Sanity check
if (!is_string($input) || $input == '') {
$input = '';
}
if (is_string($whitelist)) {
$charEnc = Codec::detectEncoding($whitelist);
$limit = mb_strlen($whitelist, $charEnc);
$ary = array();
for ($i = 0; $i < $limit; $i++) {
$ary[] = mb_substr($whitelist, $i, 1, $charEnc);
}
$whitelist = $ary;
}
$filtered = '';
$initialCharEnc = Codec::detectEncoding($input);
$_4ByteCharacterString = Codec::normalizeEncoding($input);
$limit = mb_strlen($_4ByteCharacterString, 'UTF-32');
for ($i = 0; $i < $limit; $i++) {
$c = mb_substr($_4ByteCharacterString, $i, 1, 'UTF-32');
if (Codec::containsCharacter($c, $whitelist)) {
$filtered .= $c;
}
}
if ($filtered != '') {
$filtered = mb_convert_encoding($filtered, $initialCharEnc, 'UTF-32');
}
if (!is_string($filtered)) {
$filtered = '';
}
return $filtered;
}
public function encodeCharacter($dummy_place_holder, $input)
{
$detectedCharacterEncoding = Codec::detectEncoding($input);
$c = mb_substr($input, 0, 1, $detectedCharacterEncoding);
return $this->encode($c, false);
}
/**
* Helper function.
*
* Helper method to replace carriage return and line feed characters in the
* supplied message with the supplied substitute character(s). The sequence
* CRLF (\r\n) is treated as one character.
*
* @param string $message message to process.
* @param string $substitute Replacement for CR, LF or CRLF.
*
* @return string message with characters replaced.
*/
private function _replaceCRLF($message, $substitute)
{
if ($message === null || $substitute === null) {
return $message;
}
$detectedEncoding = Codec::detectEncoding($message);
$len = mb_strlen($message, $detectedEncoding);
$crlfEncoded = '';
$nextChar = null;
$index = 0;
for ($i = 0; $i < $len; $i++) {
if ($i < $index) {
continue;
}
if ($nextChar === null) {
$thisChar = mb_substr($message, $i, 1, $detectedEncoding);
} else {
$thisChar = $nextChar;
}
if ($i + 1 < $len) {
$nextChar = mb_substr($message, $i + 1, 1, $detectedEncoding);
} else {
$nextChar = null;
}
if ($thisChar == "\r" && $nextChar == "\n") {
$index = $i + 2;
$nextChar = null;
$crlfEncoded .= $substitute;
} elseif ($thisChar == "\r" || $thisChar == "\n") {
$crlfEncoded .= $substitute;
} else {
$crlfEncoded .= $thisChar;
}
}
return $crlfEncoded;
}
/**
* Encodes a single character to Base64.
*
* @param string $immune: not used, but needs to be here to be compatible with Codec::encodeCharacter
* @param string $input the character to encode
*
* @return string the base64 encoded character
*/
public function encodeCharacter($immune = '', $c)
{
$detectedCharacterEncoding = Codec::detectEncoding($c);
$c = mb_substr($c, 0, 1, $detectedCharacterEncoding);
return $this->encode($c, false);
}
