Amazon Cognito User Pool - amazon-web-services

Question

I have a user pool in Amazon Cognito used for authenticating the APIs. And I have a user table in my database RDS where user will be inserted via application and website. I am looking for a way to auto insert user in Cognito user pool when user gets inserted in user table.
I am using java as the programming language.
Can anyone please suggest me any possible solution for it?
Can I use lambda for this? And if I can, is there any example for it, where users are inserted using lambda using java sdk?

Answer 1

You can use the AWS SDK for Java v2 to perform this task. To add a user to a user Pool, you can use this Java code. Specifically, you use the software.amazon.awssdk.services.cognitoidentityprovider.CognitoIdentityProviderClient and use the signUp method.
If you are not familiar with the AWS SDK for Java V2, refer to the DEV Guide.
Code to add a user to a user pool is:
package com.example.cognito;
//snippet-start:[cognito.java2.new_admin_user.import]
import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.cognitoidentityprovider.CognitoIdentityProviderClient;
import software.amazon.awssdk.services.cognitoidentityprovider.model.AdminCreateUserRequest;
import software.amazon.awssdk.services.cognitoidentityprovider.model.AdminCreateUserResponse;
import software.amazon.awssdk.services.cognitoidentityprovider.model.AttributeType;
import software.amazon.awssdk.services.cognitoidentityprovider.model.CognitoIdentityProviderException;
import java.util.ArrayList;
import java.util.List;
//snippet-end:[cognito.java2.new_admin_user.import]
/**
* Before running this Java V2 code example, set up your development environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class CreateUser {
public static void main(String[] args) {
final String usage = "\n" +
"Usage:\n" +
" <userPoolId> <userName> <email> <password>\n\n" +
"Where:\n" +
" userPoolId - The Id value for the user pool where the user is created.\n\n" +
" userName - The user name for the new user.\n\n" +
" email - The email to use for verifying the user.\n\n" +
" password - The password for this user.\n\n" ;
if (args.length != 4) {
System.out.println(usage);
System.exit(1);
}
String userPoolId = args[0];
String userName = args[1];
String email = args[2];
String password = args[3];
CognitoIdentityProviderClient cognitoClient = CognitoIdentityProviderClient.builder()
.region(Region.US_EAST_1)
.credentialsProvider(ProfileCredentialsProvider.create())
.build();
createNewUser(cognitoClient, userPoolId, userName, email, password);
cognitoClient.close();
}
//snippet-start:[cognito.java2.add_login_provider.main]
public static void createNewUser(CognitoIdentityProviderClient cognitoClient,
String userPoolId,
String name,
String email,
String password){
try{
AttributeType userAttrs = AttributeType.builder()
.name("email")
.value(email)
.build();
AttributeType userAttrs1 = AttributeType.builder()
.name("autoVerifyEmail")
.value("true")
.build();
List<AttributeType> userAttrsList = new ArrayList();
userAttrsList.add(userAttrs);
userAttrsList.add(userAttrs1);
AdminCreateUserRequest userRequest = AdminCreateUserRequest.builder()
.userPoolId(userPoolId)
.username(name)
.temporaryPassword(password)
.userAttributes(userAttrs)
.messageAction("SUPPRESS")
.build() ;
AdminCreateUserResponse response = cognitoClient.adminCreateUser(userRequest);
System.out.println("User " + response.user().username() + "is created. Status: " + response.user().userStatus());
} catch (CognitoIdentityProviderException e){
System.err.println(e.awsErrorDetails().errorMessage());
System.exit(1);
}
}
//snippet-end:[cognito.java2.add_login_provider.main]
}
Code to sign up a user is:
//snippet-sourcedescription:[SignUp.java demonstrates how to register a user in the specified Amazon Cognito user pool.]
//snippet-keyword:[AWS SDK for Java v2]
//snippet-keyword:[Code Sample]
//snippet-keyword:[Amazon Cognito]
//snippet-sourcetype:[full-example]
//snippet-sourcedate:[05/18/2022]
/*
Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
SPDX-License-Identifier: Apache-2.0
*/
package com.example.cognito;
//snippet-start:[cognito.java2.signup.import]
import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.cognitoidentityprovider.CognitoIdentityProviderClient;
import software.amazon.awssdk.services.cognitoidentityprovider.model.CognitoIdentityProviderException;
import software.amazon.awssdk.services.cognitoidentityprovider.model.SignUpRequest;
import software.amazon.awssdk.services.cognitoidentityprovider.model.AttributeType;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.List;
//snippet-end:[cognito.java2.signup.import]
/**
* To run this Java code example, you need to create a client app in a user pool with a secret key. For details, see:
* https://docs.aws.amazon.com/cognito/latest/developerguide/user-pool-settings-client-apps.html
*
* In addition, set up your development environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*
*/
public class SignUpUser {
public static void main(String[] args) {
final String usage = "\n" +
"Usage:\n" +
" <clientId> <secretkey> <userName> <password> <email>\n\n" +
"Where:\n" +
" clientId - The app client id value that you can obtain from the AWS Management Console.\n\n" +
" secretkey - The app client secret value that you can obtain from the AWS Management Console.\n\n" +
" userName - The user name of the user you wish to register.\n\n" +
" password - The password for the user.\n\n" +
" email - The email address for the user.\n\n";
if (args.length != 5) {
System.out.println(usage);
System.exit(1);
}
String clientId = args[0];
String secretKey = args[1];
String userName = args[2];
String password = args[3];
String email = args[4];
CognitoIdentityProviderClient identityProviderClient = CognitoIdentityProviderClient.builder()
.region(Region.US_EAST_1)
.credentialsProvider(ProfileCredentialsProvider.create())
.build();
signUp(identityProviderClient, clientId, secretKey, userName, password, email);
identityProviderClient.close();
}
//snippet-start:[cognito.java2.signup.main]
public static void signUp(CognitoIdentityProviderClient identityProviderClient,
String clientId,
String secretKey,
String userName,
String password,
String email) {
AttributeType attributeType = AttributeType.builder()
.name("email")
.value(email)
.build();
List<AttributeType> attrs = new ArrayList<>();
attrs.add(attributeType);
try {
String secretVal = calculateSecretHash(clientId, secretKey, userName);
SignUpRequest signUpRequest = SignUpRequest.builder()
.userAttributes(attrs)
.username(userName)
.clientId(clientId)
.password(password)
.secretHash(secretVal)
.build();
identityProviderClient.signUp(signUpRequest);
System.out.println("User has been signed up");
} catch(CognitoIdentityProviderException e) {
System.err.println(e.awsErrorDetails().errorMessage());
System.exit(1);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
}
}
public static String calculateSecretHash(String userPoolClientId, String userPoolClientSecret, String userName) throws NoSuchAlgorithmException, InvalidKeyException {
final String HMAC_SHA256_ALGORITHM = "HmacSHA256";
SecretKeySpec signingKey = new SecretKeySpec(
userPoolClientSecret.getBytes(StandardCharsets.UTF_8),
HMAC_SHA256_ALGORITHM);
Mac mac = Mac.getInstance(HMAC_SHA256_ALGORITHM);
mac.init(signingKey);
mac.update(userName.getBytes(StandardCharsets.UTF_8));
byte[] rawHmac = mac.doFinal(userPoolClientId.getBytes(StandardCharsets.UTF_8));
return java.util.Base64.getEncoder().encodeToString(rawHmac);
}
//snippet-end:[cognito.java2.signup.main]
}
This code example assumes that the user pool requires a Client secret when adding a user. More info here:
Configuring a user pool app client
After you get the user details from the database, use this Cognito code to add the user to a user pool. Notice you need these input values:
clientId - The app client id value that you can obtain from the AWS Management Console.\n\n" +
secretkey - The app client secret value that you can obtain from the AWS Management Console.\n\n" +
userName - The user name of the user you wish to register.\n\n" +
password - The password for the user.\n\n" +
email - The email address for the user.\n\n";
This Java code can be wrapped in an AWS Lambda function that uses the Java Lambda runtime API.