private Task <FileOperationContext> EncryptionUpgradeWorkAsync(IDataStore store, IProgressContext progress) { FileOperationsController operationsController = new FileOperationsController(progress); operationsController.QueryDecryptionPassphrase = HandleQueryDecryptionPassphraseEventAsync; operationsController.KnownKeyAdded = new AsyncDelegateAction <FileOperationEventArgs>(async(FileOperationEventArgs e) => { await _knownIdentities.AddAsync(e.LogOnIdentity); }); return(operationsController.EncryptionUpgradeAsync(store)); }