AWS Cognito

AWS Cognito User Pools: The Basics and a Quick Tutorial

What Is an AWS Cognito User Pool? 

AWS Cognito is a cloud service designed to facilitate user management and authentication for web and mobile applications. AWS Cognito user pools allow developers to manage user sign-up, sign-in, and access control via a simple interface, supporting both social identity providers like Google, Facebook, and Apple, as well as enterprise identity providers via SAML.

By using AWS Cognito user pools, developers can also implement features like multi-factor authentication and email or phone verification, enhancing the security aspect of user identities. 

Technically, an Amazon Cognito user pool is a user directory, implemented as an OpenID Connect (OIDC) identity provider (IdP), which provides capabilities like security, identity federation, application integration, and user experience customization.

In this article:

Features of Amazon Cognito User Pools

Using Cognito user pools offers the following advantages:

  • Sign-up: AWS Cognito simplifies the sign-up process by handling user onboarding. Users can register directly in the user pool or sign up through third-party identity providers, streamlining the process from multiple channels. The service also allows custom attributes to be defined, collecting unique information from users during the registration phase.
  • Sign-in: User pools built with Amazon Cognito support multiple methods of user sign-in, offering both flexibility and secure access to applications. This includes standard sign-in with a username and password, as well as the capability to integrate directly with third-party identity providers using OAuth or custom federation.
  • Hosted UI: Alleviates the need to design and implement a custom login interface. This pre-built, customizable webpage can handle sign-in and sign-up workflows, including social sign-in options integrated seamlessly within it.
  • Security: User pools provide developers with tools needed to maintain security protocols. They include features like security defense, which protects from risks such as compromised credentials, by detecting abnormal behaviors using machine learning. Cognito also offers adaptive authentication processes, such as multi-factor authentication (MFA). 
  • Monitoring and analytics: Provides detailed insights related to user engagement and application security. It facilitates tracking of events such as sign up, sign in, and password changes. This information can be directed to Amazon CloudWatch, enabling real-time analysis and alarms.

AWS Cognito User Pool vs. Identity Pool

Amazon Cognito facilitates authentication and authorization services through its two main components: user pools and identity pools.

User pools serve as fully managed user directories that help in managing and authenticating users. They allow developers to handle user sign-up, sign-in, and access control within applications. This feature is particularly beneficial for managing user identities directly within the application, including offering integration with various third-party identity providers like Google or Facebook.

Identity pools provide AWS credentials to authenticated users, enabling them to access other AWS services such as S3 or DynamoDB. This component is useful for scenarios where an application requires the user to interact with AWS services directly. Identity pools support authentication through external identity providers and can be integrated with user pools to offer a stronger solution combining authentication and access control.

Quick Tutorial: Creating an Amazon Cognito User Pool 

To start building a user pool for your application, first, navigate to the Amazon Cognito console. If not already logged in, you will need to provide your AWS credentials.

  1. Create a user pool: Click on the Create user pool button. You may need to select User Pools from the left navigation pane to find this option.

    2. Once visible, click on the top-right corner button labeled Create a user pool to initiate the setup wizard.

    3. Configure sign-in options: In the wizard’s Configure sign-in experience section, select the identity providers you want to use. Ensure only the Cognito user pool is active under Provider types, and for sign-in options, choose User name without adding additional username requirements.

    4. Set your security parameters: Next, define your security settings. Opt for the default password policy. Under Multi-factor authentication (MFA), set it to Optional MFA, allowing both Authenticator apps and SMS messages as MFA methods. Ensure that Enable self-service account recovery is active, with the delivery method for recovery messages set to email only.

    5. Customize the sign-up experience: Determine how users will verify their identity upon signing up. Enable self-registration to allow open internet sign-ups, appropriate for this example but use with caution in production. Under Cognito-assisted verification and confirmation, ensure messages for verification and confirmation are automated by Cognito, and set attribute verification to email only. Make sure that email is listed under required attributes.

    6. Integrate message delivery services: Configure message delivery settings using Amazon Cognito’s default email sender for low-volume applications. For SMS services, create a new IAM role that grants Cognito the permission to send SMS messages.

    7. Integrate the application: In the Integrate your app section, provide a name for your user pool. Cognito can also provide a UI for Sign up and Sign-in screens. Please select the checkbox for Use Cognito Authentication pages.

    8. Use a custom domain: You use a custom domain or a Cognito-provided domain. If you choose to use a custom domain, you will need to provide the domain name and Amazon Certificate Manager (ACM) Issued certificate.

    9. Define app type: Set the app type to Public client, to ensure no client secret is generated. Name your app client and add ALLOW_USER_PASSWORD_AUTH to the authentication flows under Advanced app client settings.

    10. Finalize the user pool: Review all configurations in the Review and create screen. Modify any settings if necessary and when satisfied, click Create user pool. After creation, from the User pools page, select your new user pool and note the User Pool ID and Client ID under the App integration tab, necessary for integrating with your application.

    AWS Cognito User Pool Limitations 

    While user pools can be a convenient way to manage identity in Amazon Cognito, they also have some drawbacks.

    Limited Customization Options

    Users frequently report that the service does not provide enough options to modify the user interfaces according to their specific needs. This is particularly evident in the customization of the login screen, which is not only basic in its default setup but also offers limited scope for enhancements through the provided settings. 

    For more complex customizations, developers must rely on AWS Lambda to implement custom authentication methods, adding layers of complexity and increasing development time.

    Increasing Costs at Large Scale

    AWS Cognito’s pricing structure can become a financial burden as the size of the user pool increases. The service may start as cost-effective for small to medium-sized applications, but as the user base expands, the cost escalates accordingly, and can be prohibitive if security features are needed.

    Integration Issues

    The integration capabilities of AWS Cognito are frequently cited as inadequate. Particularly, the process of integrating multiple identity providers into a single Cognito account often does not work as smoothly as the official documentation suggests. Developers find themselves needing to devise workarounds, such as using AWS Identity Pools alongside IAM roles to manage federated users. 

    Inadequate Documentation

    The AWS Cognito documentation is often described as insufficient, lacking comprehensive examples and detailed scenarios that could assist developers in understanding and using user pools effectively.

    User Interface and Login Delays

    Feedback on the AWS Cognito user interface suggests that it is not sufficiently user-friendly, with menu designs and options that do not always meet the needs of users. Additionally, the login process facilitated by Cognito is sometimes criticized for being sluggish. These interface and performance issues can lead to decreased satisfaction and hinder user engagement with applications that rely on Cognito for authentication.

    Frontegg: The Cost-Effective Cognito Alternative

    Frontegg is an easy-to-use platform that offers modern, scalable user management, including multi-factor and passwordless authentication, authorization, single sign on (SSO), and enterprise-grade security. It offers a set of pre-built, customizable, and self-served components for building and deploying SaaS apps. Frontegg offers granular role and permission management, with support for popular authentication methods like single sign-on and passwordless (magic links, speedy logins).

    The platform focuses on providing easy-to-use tools for developers to implement common user management features such as onboarding flows, billing management, and analytics, including important integrations with popular services such as Salesforce, Slack, and Twilio. Additionally, Frontegg provides a set of features to manage and secure access to applications and APIs. It also offers a plugin ecosystem that enables customers to easily extend the platform with custom functionality.

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