/**
* @param \Jose\Algorithm\JWAInterface $key_encryption_algorithm
* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
* @param \Jose\Object\JWKInterface $key
* @param \Jose\Object\RecipientInterface $recipient
* @param array $complete_headers
*
* @return null|string
*/
private function decryptCEK(Algorithm\JWAInterface $key_encryption_algorithm, Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm, Object\JWKInterface $key, Object\RecipientInterface $recipient, array $complete_headers)
{
if ($key_encryption_algorithm instanceof Algorithm\KeyEncryption\DirectEncryptionInterface) {
return $key_encryption_algorithm->getCEK($key);
} elseif ($key_encryption_algorithm instanceof Algorithm\KeyEncryption\KeyAgreementInterface) {
return $key_encryption_algorithm->getAgreementKey($content_encryption_algorithm->getCEKSize(), $content_encryption_algorithm->getAlgorithmName(), $key, $complete_headers);
} elseif ($key_encryption_algorithm instanceof Algorithm\KeyEncryption\KeyAgreementWrappingInterface) {
return $key_encryption_algorithm->unwrapAgreementKey($key, $recipient->getEncryptedKey(), $content_encryption_algorithm->getCEKSize(), $complete_headers);
} elseif ($key_encryption_algorithm instanceof Algorithm\KeyEncryption\KeyEncryptionInterface) {
return $key_encryption_algorithm->decryptKey($key, $recipient->getEncryptedKey(), $complete_headers);
} elseif ($key_encryption_algorithm instanceof Algorithm\KeyEncryption\KeyWrappingInterface) {
return $key_encryption_algorithm->unwrapKey($key, $recipient->getEncryptedKey(), $complete_headers);
} else {
throw new \InvalidArgumentException('Unsupported CEK generation');
}
}
