title: Login and Register User with CQRS and EventSourcing
body: <p>I've been experimenting with command patterns against a CQRS backend, and initially looking at examples for AccountControllers and such I suddenly find myself wondering if it makes any sense to just use commands for registering and logging in a user instead of making specific controller entry points for those. Are there any reasons I am overlooking to not do it like this? </p>
  
  <p>I guess the actual login, if that is connected to say being able to log in for a certain period of time, is something that you wouldn't want to repeat when replaying the commands. So you would have to add some kind of time limit to it - sign in only valid if command is played back less than a minute from now, for instance. Similarly, changing a password - the password would need to be stored securely. Anything else? Or known solutions?</p>