How to Assume a Cross-Account Role for Cognito? - amazon-web-services

Question

I have a Cognito userpool on AWS account acc-1, and a Java code running on acc-2, which authenticates using "adminInitiateAuth", and for some reasons, I cannot use clientInitiateAuth.
I have created a cross-account role on acc-1, to be assumed by my Java code on acc-2
Question: How can I assume the role when I am sending an authentication request to Cognito? Is it possible to use withRoleArn()?
I came across this page, which explains how to "Configure cross-account Amazon Cognito authorizer for a REST API using the API Gateway console". But it is not what I am trying to do.
My Code:
protected AdminInitiateAuthRequest createInitialRequest(String username, String password) {
Map<String, String> authParams = new HashMap<>();
authParams.put("USERNAME", username);
authParams.put("PASSWORD", password);
return new AdminInitiateAuthRequest()
.withAuthFlow(AuthFlowType.ADMIN_NO_SRP_AUTH)
.withAuthParameters(authParams)
.withClientId(whoAmIService.getCognitoClientId())
.withUserPoolId(whoAmIService.getCognitoPoolId());
}
protected boolean isAuthenticatedByCognito(String username, String password) {
AWSCognitoIdentityProvider awsCognitoIDPClient = createCognitoIDPClient();
AdminInitiateAuthRequest authRequest = createInitialRequest(username, password);
try {
AdminInitiateAuthResult authResponse = awsCognitoIDPClient.adminInitiateAuth(authRequest);
AuthenticationResultType authenticationResultType = authResponse.getAuthenticationResult();
String cognitoAccessToken = authenticationResultType.getAccessToken();
whoAmIService.setCognitoAccessToken(cognitoAccessToken);
Map<String, String> challengeParams = authResponse.getChallengeParameters();
String cognitoUserIdForSrp = challengeParams.get("USER_ID_FOR_SRP");
String cognitoUserAttributes = challengeParams.get("userAttributes");
logger.debug("Cognito authenticated user ID: {} with user attributes: {}"
, cognitoUserIdForSrp, cognitoUserAttributes);
return true;
} catch (NotAuthorizedException nae) {
logger.error("Invalid Cognito username/password provided for {}", username);
return false;
} catch (AWSCognitoIdentityProviderException acipe) {
logger.error("Base exception for all service exceptions thrown by Amazon Cognito Identity Provider", acipe);
return false;
}
}

Answer 1

I found how to do it using STS. Change this line:
AWSCognitoIdentityProvider awsCognitoIDPClient = createCognitoIDPClient();
to:
String roleARN= "YOUR_CROSS_ACCOUNT_ROLE_ARN";
String roleSessionName = "GIVE_A_SESSION_NAME";
AWSSecurityTokenService stsClient = AWSSecurityTokenServiceClientBuilder
.standard()
.withCredentials(new ProfileCredentialsProvider())
.build();
AssumeRoleRequest roleRequest = new AssumeRoleRequest()
.withRoleArn(roleARN)
.withRoleSessionName(roleSessionName);
AssumeRoleResult roleResponse = stsClient.assumeRole(roleRequest);
Credentials sessionCredentials = roleResponse.getCredentials();
BasicSessionCredentials awsCredentials = new BasicSessionCredentials(
sessionCredentials.getAccessKeyId(),
sessionCredentials.getSecretAccessKey(),
sessionCredentials.getSessionToken());
AWSCognitoIdentityProvider cognitoIPCB = AWSCognitoIdentityProviderClientBuilder
.standard()
.withCredentials(new AWSStaticCredentialsProvider(awsCredentials))
.build();