The GVfs udisks volume monitor is responsible for monitoring attached devices and automatically prompts the user to unlock encrypted volumes once they are attached. For this it calls MountOperationHandler.AskPassword, which shows a dialog to ask the user for the password. We have to patch this dialog in order to support VeraCrypt keyfiles and hidden volumes.
MountOperationHandler is part of GNOME Shell, so this work will have to be done both in GVfs and GNOME Shell.
An important aspect of this is that we want to display the name of the file container in the dialog. Current the device name is displayed but it doesn't make sense for file containers (/dev/loop0).