private function buildHeaders($key, $keySHA256, $useCopySourceHeaders)
{
if ($key) {
$headerNames = $useCopySourceHeaders ? $this->copySourceEncryptionHeaderNames : $this->encryptionHeaderNames;
if (!$keySHA256) {
$decodedKey = base64_decode($key);
$keySHA256 = base64_encode(hash('SHA256', $decodedKey, true));
}
return [$headerNames['algorithm'] => 'AES256', $headerNames['key'] => $key, $headerNames['keySHA256'] => $keySHA256];
}
return [];
}