This is useful for cases like remember-me tokens and auto-unsubscribe links where the session store isn’t suitable or available.
cookies[:remember_me] = @verifier.generate([@user.id, 2.weeks.from_now])
In the authentication filter:
id, time = @verifier.verify(cookies[:remember_me]) if time < Time.now self.current_user = User.find(id) end
By default it uses Marshal to serialize the message. If you want to use another serialization method, you can set the serializer in the options hash upon initialization:
@verifier = ActiveSupport::MessageVerifier.new('s3Krit', serializer: YAML)
In the authentication filter example above, the time condition should be reversed: we only want to find the user if time is still in the future (because it’s the valid-until time).
So the example should look like this:
One thing to note about the code above is that it could have a security issue. If the user changes his/her password, the authentication token should expire. Hence, in a production scenario you should put in the password salt or something to allow the token to become invalidated.