I am creating an Angular application, and I am having trouble wrapping my head around the proper way to ensure my application and its users is secure.
I've been reading around many stack discussions, but I believe I am missing some core understanding of what is happening, please correct any errors you see written below.
So far I have a Sinatra server with many (currently mostly hypothetical) resource routes. A user can create an account using an email address and password that is stored in a database after being hashed with BCrypt. When a user logs in, the record is retrieved from the database by email and the password checked for authentication. It is from this point I am not sure how to proceed.
Prior to this I have simply set a session variable and had the server check that the variable exists in order to correctly route logged in users. Now my application is (currently) a single HTML page that uses Angular and ui-router to display different content, so most of the requests are simply returning JSON content.
It is my understanding that Restful applications should generally not use sessions, or rather that the server should respond identically to identical requests and not have its own data that shapes a response. But if I do not store something in a session variable, how could the server know that the client making the request has the correct permissions? And are sessions not stored in the browser anyway, thus not part of the server?
I believe from what I have read, it is possible to create a token which is essentially a large random string, return that string to the client and also store it in a database with a timestamp. The client then provides this token when making requests and the server hits the database to verify it exists and valid. But would the client not also have to store that string in a cookie? I suppose the angular application could store the token in a variable, which would persist while using the ui-router but not if the users navigates using the address bar.
I also do not understand how Basic Auth may or may not fit into this picture. Any help would be greatly appreciated, as well as a pointer to some good resources where I may find a better understanding of these concepts in general.
You want to read up on JWT. There are JWT libraries for Ruby and Angular.
I know you aren't using Node for your backend but a very easy way to see all the pieces working together is to run the angular-fullstack Yeoman generator. It uses JWT and the code is easy to follow.