public async Task <StoredItemMetadata> GetItemMetadata(string repo, string passphrase, string itemId)
{
var encryptedMetadata = await driver.ReadMetadata(repo, itemId);
var serializedPacket = Encoding.ASCII.GetString(encryptedMetadata);
var encodedPassphrase = Encoding.UTF8.GetBytes(passphrase);
var packet = PassphraseEncryptedPacket.FromString(encodedPassphrase, serializedPacket);
var binaryMetadata = crypto.PassphraseDecrypt(encodedPassphrase, packet);
var rawJson = Encoding.UTF8.GetString(binaryMetadata);
return(JsonSerializer.Deserialize <StoredItemMetadata>(rawJson));
}