Authentification and security model in client/server aplications

Question

I'm developing custom client/server application that requires client to log in with their username and password. The user accounts are not related to Windows/AD accounts in any way. After login, client application will request other services from server system.

My question is what is the best way to implement this? What kind of architecture would fit best here? I guess some kind of ticket/token authentication system needs to be implemented???

Thanks

Answer 1

You haven't said much about your architecture, other than it is Client/Server, so I am assuming you're using some sort of forms designer like Windows Forms in VS. In these cases I have always used some form of database table authentication, as it is easy, simple to setup, and reasonably secure. You can even set up groups and roles this way, without much fuss.

Table:  Users
Fields: UserID   PK
        Login    Text
        Password Text
        ...

Table:  Roles
Fields: RoleID   PK
        Role     Text
        ...

Table:  UserRoles
Fields: UserID    FK
        RoleID    FK

Answer 2

You may in fact want to implement a system which passes "tickets" along between the different parts (login server, client, app server). This ticket will contain basic information such as the user ID (the username, the row id, etc). This ticket will either be encrypted with a secret key that the authorized servers share, or will be stamped with a hash of the ticket contents salted with a secret key that the servers share. The first way makes it possible for only the authorized servers to create and read the ticket, and the second way makes it possible for the authorized servers to verify that only the authorized servers could have created the ticket but permits anyone to read the ticket. All app servers will check the ticket (by attempting to decrypt it or by verifying that the hash matches) before proceeding with any actions that should be protected. If this is a web app, then cookies are a good place to store the ticket.