title: AWS Cognito Sign-In (Android)
body: <p>I am trying to figure out how to sign in a User with AWS Cognito. The <a href="https://docs.aws.amazon.com/cognito/latest/developerguide/tutorial-integrating-user-pools-android.html" rel="nofollow noreferrer">tutorials</a> all seem to deal with Users from a standpoint of signing up Users, not signing them in. I do not want the users to go through a sign-up process; that will be done elsewhere, by our office users. I just want to have, in this app, a flow that has them enter their existing username and password and sign in.</p>
  
  <p>My current understanding of things is that Cognito User Pools only supports either sign-in using an authentication provider like Facebook or Google, or non-authenticated sign-in, which I am having trouble determining if this uses a username and password or not (I couldn't find anywhere in that flow to supply a username and password, in any case). There is also Cognito Federated Identities, which also seems to be called Cognito User Pools half the time, which has the aforementioned signup tutorials, but nothing about just signing in an existing User.</p>
  
  <p>Do I have to use the Federated Identities version of User Pools in order to be able to sign in with a username and password? If not, how do I do that with non-Federated User Pools? If so, how do I make a flow just for signing in, not signing up? I am trying to grab just the pieces that look relevant from the aforementioned tutorial, but I am getting frustrated as I have been chasing my tail on this for weeks now, with only more layers of stuff that relies on other stuff that relies on other stuff in sight.</p>