/**
* Parses an object identifier except for the first octet, which is parsed
* differently. This way relative object identifiers can also be parsed
* using this.
*
* @param $binaryData
* @param $offsetIndex
* @param $octetsToRead
*
* @throws ParserException
*
* @return string
*/
protected static function parseOid(&$binaryData, &$offsetIndex, $octetsToRead)
{
$oid = '';
while ($octetsToRead > 0) {
$octets = '';
do {
if (0 === $octetsToRead) {
throw new ParserException('Malformed ASN.1 Object Identifier', $offsetIndex - 1);
}
$octetsToRead--;
$octet = $binaryData[$offsetIndex++];
$octets .= $octet;
} while (ord($octet) & 0x80);
$oid .= sprintf('%d.', Base128::decode($octets));
}
// Remove trailing '.'
return substr($oid, 0, -1) ?: '';
}
/**
* @param int|string $identifier
*
* @return int
*/
public static function getTagNumber($identifier)
{
$firstOctet = self::makeNumeric($identifier);
$tagNumber = $firstOctet & self::LONG_FORM;
if ($tagNumber < self::LONG_FORM) {
return $tagNumber;
}
if (is_numeric($identifier)) {
$identifier = chr($identifier);
}
return Base128::decode(substr($identifier, 1));
}
/**
* @param int|string $identifier
*
* @return int
*/
public static function getTagNumber($identifier)
{
$firstOctet = substr($identifier, 0, 1);
if (!IdentifierManager::isLongForm($firstOctet)) {
return ord($firstOctet) & self::LONG_FORM;
}
$firstOctet = self::makeNumeric($identifier);
if (is_numeric($identifier)) {
$identifier = chr($identifier);
}
return Base128::decode(substr($identifier, 1));
}