/**
* Get PRF by algorithm identifier.
*
* @param PRFAlgorithmIdentifier $algo
* @throws \UnexpectedValueException
* @return self
*/
public static function fromAlgorithmIdentifier(PRFAlgorithmIdentifier $algo)
{
$oid = $algo->oid();
if (array_key_exists($oid, self::MAP_HASH_OID_TO_CLASS)) {
$cls = self::MAP_HASH_OID_TO_CLASS[$oid];
return new $cls();
}
throw new \UnexpectedValueException("PRF algorithm " . $algo->oid() . " not supported.");
}
protected function _paramsASN1()
{
$elements = array();
$elements[] = new OctetString($this->_specifiedSalt);
$elements[] = new Integer($this->_iterationCount);
if (isset($this->_keyLength)) {
$elements[] = new Integer($this->_keyLength);
}
if ($this->_prfAlgo->oid() !== AlgorithmIdentifier::OID_HMAC_WITH_SHA1) {
$elements[] = $this->_prfAlgo->toASN1();
}
return new Sequence(...$elements);
}
