RFE: allow to configure a custom auth-dialog
The current auth-dialog tries to reimplement a web browser, but it cannot cover all use cases. Specifically, when a complex multi-factor authentication scheme is used, it falls flat. Authentication can differ not only by provider but by domain as well. At $work, the multi-factor authentication can be a combination of 5 different mechanisms.
The only way to use a custom auth-dialog right now is to make a copy of /usr/lib/NetworkManager/VPN/nm-openconnect-service.name somewhere, and use NM's NM_VPN_PLUGIN_DIR environment variable to point to it. It's clunky, gets out of date, intended for dev/testing use, and not well supported by GUIs like gnome-shell.
It would be great to have a configuration option that points to another binary, and have nm-openconnect-auth-dialog just call it if configured.