/**
* Parse 'attributeTypeAndValue'.
*
* attributeType "=" attributeValue
*
* @param int $offset
* @throws \UnexpectedValueException
* @return array A tuple of [type, value]. Value may be either a string or
* an Element, if it's encoded as hexstring.
*/
private function _parseAttrTypeAndValue(&$offset)
{
$idx = $offset;
$type = $this->_parseAttrType($idx);
$this->_skipWs($idx);
if ($idx >= $this->_len || "=" != $this->_dn[$idx++]) {
throw new \UnexpectedValueException("Invalid type and value pair.");
}
$this->_skipWs($idx);
// hexstring
if ($idx < $this->_len && "#" == $this->_dn[$idx]) {
++$idx;
$data = $this->_parseAttrHexValue($idx);
try {
$value = Element::fromDER($data);
} catch (DecodeException $e) {
throw new \UnexpectedValueException("Invalid DER encoding from hexstring.", 0, $e);
}
} else {
$value = $this->_parseAttrStringValue($idx);
}
$offset = $idx;
return array($type, $value);
}
/**
*
* @see \ASN1\Element::_decodeFromDER()
* @return self
*/
protected static function _decodeFromDER(Identifier $identifier, $data, &$offset)
{
$idx = $offset;
if (!$identifier->isConstructed()) {
throw new DecodeException("Structured element must have constructed bit set.");
}
$length = Length::expectFromDER($data, $idx);
$end = $idx + $length->length();
$elements = array();
while ($idx < $end) {
$elements[] = Element::fromDER($data, $idx);
// check that element didn't overflow length
if ($idx > $end) {
throw new DecodeException("Structure's content overflows length.");
}
}
$offset = $idx;
// return instance by static late binding
return new static(...$elements);
}
/**
*
* @see \ASN1\Type\Tagged\ExplicitTagging::explicit()
* @return UnspecifiedType
*/
public function explicit($expectedTag = null)
{
$idx = $this->_offset;
Length::expectFromDER($this->_data, $idx);
$element = Element::fromDER($this->_data, $idx);
if (isset($expectedTag)) {
$element->expectType($expectedTag);
}
return new UnspecifiedType($element);
}
