Our project consists of Java back end(spring web application) and iOS and Android client applications. Now we need to add an authentication for client applications to Java back end. The idea is to register user for the first time using an external web service. At this step user provides full credentials(login and "big" password) and chooses some PIN for further authorization. After that primary step is complete successfully, user should be able to authenticate using his login and PIN(which he chose previously himself). Those login and pin should be stored in our DB. We should also be able to destroy that "session" and PIN whenever is necessary. We expect web application to have up to 10 000 registered users with up to 1000 users being online simultaneously.
We also don't plan to use any separate Authentication server, we plan to embed security into web application(back end) itself.
I've been investigating 2 different approaches. First is usual spring @EnableWebSecurity approach. This seems pretty straight forward, but some people say it will create "sessions", which are bad for the server. Session will consume lots of memory, and overall impact on performance will be bad. Is it true?
The other approach is to use Spring Oauth2 implementation. I didn't have time to study it properly, this seems to be a little bit of an overkill to me. Is it worth to study for our needs? (we are running out of time btw).
I also need to have some proper DB sctructure for the security needs.
So the question is, what is the best approach for our situation? Are there any open source projects, solving similar issue? I would appreciate any help.
Thank you.