Amazon Cognito set identityId using developer authentication Obj C

Question

I am trying to authenticate my user using Cognito and developer authenticated Identities. My question is how do I set the identityId to the correct one returned from my developer backend in iOS using objective-c?

If I make the calls manually in the code or using postman the correct id is returned by my server and Cognito recognizes it and correctly swaps the tokens.

The iOS framework seems to be self assigning an identityId that is not correct. I am really struggling to understand the documentation as much of it is outdated and vague.

Here is my code below:

NSLog(@"Complete login");

    NSMutableDictionary *merge = [NSMutableDictionary dictionaryWithDictionary:self.credentialsProvider.logins];
    [merge addEntriesFromDictionary:logins];

    self.credentialsProvider.logins = merge;

    // Force a refresh of credentials to see if we need to merge
    task = [self.credentialsProvider refresh];

    NSLog(@"Complete login 2-- %@", self.credentialsProvider.identityId); //The identityId assigned is incorrect...
    NSLog(@"Complete login 2-- %@", self.credentialsProvider.identityPoolId); //The identityPoolId is correct

SOME CLARITY BELOW: This is how it works so far: 1 - When the app runs its automatically assigns a random identityId from amazon (So the user is initially unauthenticated). 2 -The user enters their credentials then my code does a URL request to my backend which returns a valid token and the correct identityId for the username and password. 3 -Now this new identityId needs to be initialized in the code somehow to override the old unauthenticated identityId. 4 -The new idendityId and token which returned from my server need to be sent to Cognito for final authentication and Cognito returns more authentication. When I say manually I am send the request via postman.

In short: 1: How do I change/set my identityId? 2: How do I send the updated credentials received from my back end in my client to Cognito?

Answer 1

identityId field in AWSCognitoCredentialsProvider instance has readonly attribute so it cannot be changed once it initialized. The only way to set it is in its initialization.

id<AWSCognitoCredentialsProvider> credentialsProvider =
   [[AWSCognitoCredentialsProvider alloc]
        initWithRegionType:<Region>
          identityProvider:identityProvider
             unauthRoleArn:nil
               authRoleArn:nil];

After the user is authenticated make sure to update the logins map as follow:

credentialsProvider.logins = @{DeveloperProviderName: userIdentifier}
[credentialsProvider refresh];

source: http://docs.aws.amazon.com/cognito/latest/developerguide/developer-authenticated-identities.html

p.s.: make sure you implement the identity provider correctly and in the refresh method you should set the identityId

- (AWSTask *)refresh {
    /*
     * Get the identityId and token by making a call to your backend
     */
    // Call to your backend

    // Set the identity id and token
    self.identityId = response.identityId;
    self.token = response.token;
    return [AWSTask taskWithResult:self.identityId];
}