CognitoCachingCredentialsProvider (Android) - how to logout and remove cached credentials - amazon-web-services

Question

I'm using the developer-authenticated technique for implementing this class, as described here. So far, I've been able to implement this class and build a framework in which I check CognitoCachingCredentialsProvider.getCachedIdentityId() to see if a user has logged in (and therefore doesn't need to re-authenticate by entering an email and password). To do this, I'm using a series of static methods in a class called Util, since these only need to be instantiated once. This is what it looks like:
package com.pranskee.boxesapp;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import org.json.JSONException;
import org.json.JSONObject;
import android.content.Context;
import android.util.Log;
import com.amazonaws.auth.AWSAbstractCognitoIdentityProvider;
import com.amazonaws.auth.CognitoCachingCredentialsProvider;
import com.amazonaws.mobileconnectors.cognito.*;
import com.amazonaws.regions.Regions;
public class Util {
private final static String TAG = "Util";
private static final String AWS_ACCOUNT_ID = {acct id};
private static final String COGNITO_POOL_ID = {pool id};
private static final String COGNITO_ROLE_AUTH = {auth arn};
private static final String COGNITO_ROLE_UNAUTH = {unauth arn}
private static CognitoCachingCredentialsProvider sCredProvider;
private static UserIdentityProvider sIdProvider;
private static CognitoSyncManager sSyncManager;
private Util() {
}
public static CognitoCachingCredentialsProvider getCredProvider(
Context context) {
if (sCredProvider == null) {
if (sIdProvider == null) {
CognitoCachingCredentialsProvider tmpProvider = new CognitoCachingCredentialsProvider(
context.getApplicationContext(), AWS_ACCOUNT_ID,
COGNITO_POOL_ID, COGNITO_ROLE_UNAUTH,
COGNITO_ROLE_AUTH, Regions.US_EAST_1);
if (tmpProvider.getCachedIdentityId() != null) {
sCredProvider = tmpProvider;
} else {
sCredProvider = null;
}
} else {
sCredProvider = new CognitoCachingCredentialsProvider(
context.getApplicationContext(), sIdProvider,
COGNITO_ROLE_UNAUTH, COGNITO_ROLE_AUTH);
}
}
return sCredProvider;
}
public static UserIdentityProvider getIdentityProvider(Context context,
String email, String pwd) {
if (sIdProvider == null) {
sIdProvider = new UserIdentityProvider(AWS_ACCOUNT_ID,
COGNITO_POOL_ID, context.getApplicationContext(), email,
pwd);
Map logins = new HashMap();
logins.put({Developer Provider Name}, sIdProvider.getToken());
sIdProvider.setLogins(logins);
}
return sIdProvider;
}
public static boolean isLoggedIn(Context context) {
if (getCredProvider(context) == null) {
return false;
}
return true;
}
private static CognitoSyncManager getSyncManager(Context context) {
if (sSyncManager == null) {
sSyncManager = new CognitoSyncManager(
context.getApplicationContext(), Regions.US_EAST_1,
sCredProvider);
}
return sSyncManager;
}
protected static class UserIdentityProvider extends
AWSAbstractCognitoIdentityProvider {
private Context context;
private String email;
private String password;
public UserIdentityProvider(String accountId, String identityPoolId,
Context c, String em, String pwd) {
super(accountId, identityPoolId);
context = c;
email = em;
password = pwd;
}
#Override
public String refresh() {
try {
ServerCommunicator server = new ServerCommunicator(context);
//this is a server call, which makes the call GetOpenIdTokenForDeveloperIdentityRequest after I authenticate the user and send AWS my user's token
String response = server.initUserLoginAsyncTask()
.execute(email, password).get();
JSONObject responseJSON = new JSONObject(response);
String identityId = responseJSON.getString("id");
String token = responseJSON.getString("token");
this.setToken(token);
this.setIdentityId(identityId);
update(identityId, token);
return token;
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
#Override
public String getProviderName() {
return {Developer Provider Name};
}
}
}
Now, I want to also implement a Logout. I think what I'd need to do is remove the cached Identity Id somehow, but I'm not sure what the best method would be to do that. Or, maybe it's not that at all, and I need to do something differently entirely. Either way, I just want to implement the intended behavior of allowing a user to select to "Log Out" of my app, which causes Cognito to forget that that ID was logged into the Identity Pool and invalidates any attempt to establish an Identity ID again without going through my authentication process again.

Answer 1

Logout would be a two steps process, first you need to logout from the Identity Provider that authenticated your user (Amazon, Google, Facebook or your own) Instructions on how to do this are specific to your provider.
From the CognitoIdentity side, you need to tell the CredentialsProvider to clear all state and cache associated with your identity. Using Android SDK, you can call clear() on the CredentialsProvider (see http://docs.aws.amazon.com/AWSAndroidSDK/latest/javadoc/com/amazonaws/auth/CognitoCredentialsProvider.html)