I am looking for the alternative ways to sign in to Odoo Web UI back end and I am rather new to Odoo Framework.

I am currently using Odoo V10, looking to upgrade to V12 as soon as I can, but I have alot of clients still using Odoo V10 which I need to support.

From what I know about Odoo currently,
1) Odoo have a /web/login URL for users to login into Web back end with username and password manually

2) XMLRPC API that connects only to the odoo database to do CRUD operation using another application.
​3) OAuth2 Client module which only works with google sign in at the moment by default in V10.

4) Free OAuth2 modules, that requires me to develop an OAuth2 Server to sign in which I have difficult understanding and developing an OAuth2 Server in Java due to the technical requirements of the project.

5) I have found in one of the earlier posts in this forum, that a function on/web/login URL used to accept Database name, username and password parameters in URL Params is removed as it could be easily exploited by hackers.

6) I also could not find any modules in odoo apps store that fits my requirement.

I hope if anyone could share other alternatives ways of login to web UI back end of Odoo securely?