Understanding Single Sign-On (SSO) Architecture

Single sign-on (SSO) is a mechanism that allows users to authenticate once and access multiple applications without the need to enter login credentials again. #sso streamlines the user experience and reduces the burden of remembering multiple usernames and passwords. This blog post will explore the architecture of SSO and explain how it works.

SSO Architecture

SSO typically involves three main components: the identity provider (IDP), the service provider (SP), and the user. The IDP is responsible for authenticating the user and providing a secure token to the SP, which in turn grants access to the requested application.

The following Mermaid code illustrates the SSO architecture:

User

The user initiates the SSO process by accessing an application that requires authentication. The user is redirected to the IDP's login page, where they enter their credentials. Upon successful authentication, the IDP provides the user with a secure token, which is then sent to the SP to request access to the requested application.

Identity Provider

The IDP is responsible for authenticating the user and providing a secure token to the SP. The IDP's login page is the first step in the authentication process. The user enters their credentials, and the IDP verifies them against a user directory or database. Once the user is authenticated, the IDP provides an identity assertion, which is a secure token that contains information about the user and their permissions.

Service Provider

The SP is responsible for granting access to the requested application. The SP receives the identity assertion from the IDP and uses it to grant access to the requested application. The SP also maintains a shared secret with the IDP, which is used to validate the identity assertion.

Key

The shared secret is a cryptographic key that is used to validate the identity assertion. The IDP and SP share this secret, which is used to sign and verify the identity assertion.

Single Logout

The SSO process does not end when the user logs out of a single application. To fully log out of all applications, the user must initiate a single logout request. The SP sends the request to the IDP, which then invalidates the user's identity assertion.

Conclusion

SSO is a powerful mechanism that simplifies the user experience and reduces the burden of managing multiple usernames and passwords. The architecture of SSO involves three main components: the identity provider, the service provider, and the user. The IDP is responsible for authenticating the user and providing a secure token to the SP, which in turn grants access to the requested application. The SP maintains a shared secret with the IDP, which is used to validate the identity assertion. Finally, the user can initiate a single logout request to fully log out of all applications.