*/ private const SUPPORTED_TYPES = [ Element::TYPE_UTF8_STRING, Element::TYPE_PRINTABLE_STRING, Element::TYPE_BMP_STRING, Element::TYPE_UNIVERSAL_STRING, Element::TYPE_T61_STRING, ]; /** * @param int $_type ASN.1 type tag of the string */ private function __construct( private readonly int $_type ) { } public static function create(int $_type): self { return new self($_type); } /** * Check whether transcoding from given ASN.1 type tag is supported. * * @param int $type ASN.1 type tag */ public static function isTypeSupported(int $type): bool { return in_array($type, self::SUPPORTED_TYPES, true); } /** * @param string $string String to prepare * * @return string UTF-8 encoded string */ public function apply(string $string): string { switch ($this->_type) { // UTF-8 string as is case Element::TYPE_UTF8_STRING: // PrintableString maps directly to UTF-8 case Element::TYPE_PRINTABLE_STRING: return $string; // UCS-2 to UTF-8 case Element::TYPE_BMP_STRING: return mb_convert_encoding($string, 'UTF-8', 'UCS-2BE'); // UCS-4 to UTF-8 case Element::TYPE_UNIVERSAL_STRING: return mb_convert_encoding($string, 'UTF-8', 'UCS-4BE'); // TeletexString mapping is a local matter. // We take a shortcut here and encode it as a hexstring. case Element::TYPE_T61_STRING: $el = T61String::create($string); return '#' . bin2hex($el->toDER()); } throw new LogicException(sprintf('Unsupported string type %s.', Element::tagToName($this->_type))); } }