Web app security architecture

Question

I have a Java Spring driven REST API server connecting with PostgreSQL database and a Spring Web Server in Java that is serving content from the REST API to the client using JavaScript (now browsers, but in the future also mobile apps).

I've read a number of articles and topics how one can secure a REST API, but I haven't been able to make a final decision yet. I don't want to have Basic Authorization, because it doesn't make sense as I would need to store credentials in JavaScript that can be easily accessed and read by anyone entering the webpage and developer console. I'd like not to show any credentials to the end user so I can't keep them on the client's side.

I've read a lot about JWT and almost decided to implement it, but I've heard it has some drawbacks and haven't been so sure since then if it's the option I would like to choose. I know there is also oAuth 1.0 or oAuth 2.0 but I don't know if I want to have something this complicated. I would also like to store hashed user credentials in my own database in order not to be depended to any other credential providers like social media or Google.

Now I'm making another layer on my web server as a proxy hoping that it will allow me to authenticate user on this proxy level using Spring Security and having some kind or cookies or something to authenticate, but I'm not so sure if its doable this way and it increases the respond time, adds complexity and needs me to write controller methods for these endpoints. My architecture now is of the following:

Client (browser) -> Webserver -> REST API server -> db

I've also denied all external connections and allowed only localhost access to REST API on tomcat level so that I'd have to implement the security level only on the web server allowing free information transit between the webserver and REST API as it is not reachable anyway.

Web server and REST API are on the same server running as Tomcat instances.

I'm also not so sure if this kind of architecture will allow me to authenticate mobile app clients through the web server.

I would be very grateful for any piece of advice you would have for me in this matter. I'm not so experienced in security, so I'm a bit lost what I should do. Does this kind of architecture any sense or should I simply ask REST API directly from any type of clients, be it a webpage or a mobile app from different IPs and secure Rest API only? And if I want to secure some subpages of my webpage or parts of mobile app should that be an completely other layer?

Thank you for your help.

Answer 1

You have already gone through OAuth, JWT tokens etc. If you don't want to use them,then you can create your own token based authentication system.(say 'TokenHandler').

How this TokenHandler will work ?

TokenHandler will be like a gateway server i.e your every REST API request will route through this server application. So you will address your confusion of mobile and web application call with a authToken in header. Main responsibility of this server applciation is to accept the token and validate against the database where all token details are maintain. This DB will have information regarding timestamp when token was last used to validate, to decide your validation rule .

How Token will get generated ? Token can be any random 64 digit alphanumeric string and will be generated and updated in DB during every single login activity. Login webservice returns this token in response body.

What can be rules for validation ? It can be depending on your business logic. I preferred to keep active session window of 15 mins. Means if you access the webservice you will get active window of 15 more minutes. If you didn't access any service for 15 consecutive minutes then from 16th Minute you will need to login again to access further calls. This part can change according to requirements.

How client side will handle this ? Client side will store this token and pass this token with every request call. Token Handler will validate and redirects it's request to the application server . So your one token handler can be used to server authentication of multiple applcation servers. This you can achieve by application end point identifer.

I will like to discuss further if you have any questions or suggestions .