Single Sign-On (SSO) is a user authentication service that allows a user to use one set of login credentials (e.g., username and password) to access multiple applications. The main benefit of SSO is that it enables users to access resources across different systems without the need to repeatedly log in, thereby improving user experience and productivity. SSO works by establishing a trusted relationship between an identity provider (IdP) and various service providers (SP).
When a user tries to access a service provider, the service provider requests authentication from the identity provider. If the user has already been authenticated by the IdP, they are granted access without needing to enter login credentials again. This is accomplished through the use of tokens or tickets, which are generated by the IdP and passed to the SP. These tokens contain the user’s authentication information and are encrypted to prevent unauthorized access.
Amazon Cognito is a cloud-based user authentication service that enables developers to add sign-up, sign-in, and access control to web and mobile apps. It scales to millions of users and supports SSO with social identity providers including Google, Facebook, Apple, and Amazon, as well as enterprise identity providers through SAML or OIDC.
Amazon Cognito allows developers to manage user profiles, keep track of their application’s user data in sync across devices, and handle the process of user registration and sign-in for their web or mobile apps.
Amazon Cognito consists of two main components: user pools and identity pools. User pools are user directories that provide sign-up and sign-in options for your app users. Identity pools allow you to grant your users access to other AWS services. They support anonymous guest users and can provide AWS credentials to federated identities from a variety of sources.
To better understand how Amazon Cognito provides SSO, we’ll first review the main use cases in which this authentication solution is used.
A user pool is a directory that can contain up to millions of users. It serves as a secure and scalable user directory that can facilitate sign-ups and sign-ins. This scenario is especially useful for applications that require user management and profile capabilities.
The authentication process is straightforward. When a user signs in, they receive a JWT (JSON Web Token), which is used for subsequent authentication requests. This token is a secure way to confirm the identity of the user and ensure they have the necessary permissions.
User pools also offer built-in, customizable UI pages to handle the entire lifecycle of user management. These include registration, sign-in, password recovery, and account verification.
The user pool can also be used to access server-side resources. This typically involves leveraging AWS Identity and Access Management (IAM) in combination with Cognito.
When a user signs in through a user pool, Cognito returns JWTs, which your app can use to determine whether the user is authorized to access server-side resources. The app can exchange these tokens for temporary, limited-privilege AWS credentials through an identity pool. This allows your app to access your AWS resources, such as Amazon S3 or Amazon DynamoDB.
This scenario is useful for applications that require user data to be stored securely and accessed across multiple devices or platforms. It eliminates the need for the application to manage its user data, relying on AWS to handle data synchronization and state management.
Another option is to authenticate users through a third party, like Facebook, Google, or a SAML-compatible identity provider, and then grant these users access to AWS services using an identity pool.
The user authenticates with the third-party identity provider, and then the app exchanges the third-party token for AWS temporary credentials through the identity pool. This allows the user to access AWS services under the identity provided by the third-party provider.
This approach is suitable for applications that rely on third-party identity providers for user authentication but also require access to AWS services. It provides a seamless user experience by leveraging the user’s existing identity while maintaining secure access to AWS resources.
Related content: Read our AWS SSO guide
When you set up SSO with Cognito, Amazon Cognito acts as a mediator between your application and the external identity providers, managing user identities and granting the correct permissions.
When a user logs into an application using SSO with Cognito, Cognito communicates with the external identity provider to verify the user’s identity. Once the identity is confirmed, Cognito generates a session for the user in the form of JWT tokens. These tokens contain claims about the user’s identity and permissions. The application can then use these tokens to grant the user access to its resources without requiring the user to log in again.
Cognito’s SSO implementation supports various identity providers, including social identity providers (like Google, Facebook, Apple, and Amazon), SAML 2.0 identity providers, and OpenID Connect (OIDC) providers.
One significant limitation of Amazon Cognito is the complexity involved in its configuration and setup process. Navigating through its various components, configurations, and options can be difficult, especially for those not well-versed in the AWS ecosystem. This can be a barrier to entry for new or less technical users.
Another limitation is related to the token expiration time. Amazon Cognito does not allow for an extension of the token expiration time beyond its default settings. This limitation can create challenges, as frequent token renewals might be necessary, potentially leading to a less seamless user experience.
Amazon Cognito offers limited options for customization—from the user interface to error message localization—which can be a constraint for developers looking to provide a tailored user experience. Cognito does allow some customization of workflows, but this requires integrating additional services like AWS Lambda.
Related Content: Read Our AWS Cognito Pricing Guide
This tutorial will guide you through the steps to configure a user pool in Amazon Cognito.
Start by navigating to the Amazon Cognito console and clicking the Manage User Pools button to launch the setup flow.
During setup, you will define the attributes required for user registration. It is common practice to require only an email address and advisable to enable case insensitivity for username inputs to prevent login errors. Designate the email address as a mandatory attribute that will be created or updated during the user sign-in process.
Configure multi-factor authentication (MFA) if it is necessary for your security needs. If MFA is enabled, users will be required to provide an additional form of identification, which enhances the security of the system.
Enable settings that allow users to recover their passwords. Select the relevant option from the list. This feature is crucial if your application allows users to sign up directly through Cognito, providing a method for resetting forgotten passwords.
Under Password policy settings, define the requirements for password strength, including minimum length and the use of numbers, special characters, and both uppercase and lowercase letters. These policies ensure that user accounts are secured with strong passwords.
Create different App clients for various environments, such as development or production. Each client should have its own callback URLs and secrets to accommodate the specific needs of each environment.
If your setup restricts users from authenticating directly through user pools, ensure that they use specified SSO identity providers. Adjust the time-to-live settings for tokens and enable necessary authentication flows, such as the Secure Remote Password (SRP) protocol, to enhance security.
In the Federated Identity Providers section, add or configure SAML-based providers following detailed instructions. Configure providers such as Google and adjust attribute mappings, including email, names, and usernames, to align with your application’s requirements.
You should now have an Amazon Cognito user pool that supports your application’s user authentication needs, including seamless SSO capabilities.
Related Content: Read Our AWS Cognito React Guide
Frontegg is a modern customer identity platform offering a robust alternative to Amazon Cognito. It provides a range of features tailored for seamless Single Sign-On (SSO) integration. With a focus on ease of use, Frontegg enables customers to configure their SSO settings independently, reducing the burden on development teams.
By providing a comprehensive, user-friendly SSO solution, Frontegg stands out as a powerful alternative to Amazon Cognito. It offers a faster, more flexible approach to integrating secure, enterprise-ready authentication, allowing development teams to focus on their core product development while ensuring a seamless user experience.
