public static function hash_equals($knownString, $userInput)
{
if (!is_string($knownString)) {
trigger_error('Expected known_string to be a string, ' . gettype($knownString) . ' given', E_USER_WARNING);
return false;
}
if (!is_string($userInput)) {
trigger_error('Expected user_input to be a string, ' . gettype($userInput) . ' given', E_USER_WARNING);
return false;
}
$knownLen = Binary::strlen($knownString);
$userLen = Binary::strlen($userInput);
if ($knownLen !== $userLen) {
return false;
}
$result = 0;
for ($i = 0; $i < $knownLen; ++$i) {
$result |= ord($knownString[$i]) ^ ord($userInput[$i]);
}
return 0 === $result;
}
/**
* Returns the number of bytes in a string.
*
* @param string $string The string whose length we wish to obtain
*
* @return int
*/
public static function safeStrlen($string)
{
return Binary::strlen($string);
}
