How to Implement Single Sign-On for Businesses

In today’s digital world, businesses use many applications to get work done. However, managing multiple passwords for these tools can create serious headaches. Employees often have to remember different passwords for every application, leading them to write down passwords or store them in unsafe places. When a new employee joins, the IT team has to set up accounts on multiple platforms, which takes time. On the other hand, when an employee leaves, there’s a risk that their access to some systems might not be removed, putting the company’s security at risk.

If you’re looking to simplify and centralize access in your company, implementing Single Sign-On (SSO) is exactly what you need. Now, you’re in the right place, this short guide will walk you through the essentials of implementing SSO in your organization. And if you need expert help with these services, please don’t hesitate to contact us. Take a look!

Understanding Single Sign-On (SSO)

Single Sign-On (SSO) is an authentication solution that allows users to log in to multiple applications and websites with a single set of credentials. This simplifies access across various platforms, enabling users to sign in once and seamlessly access all necessary applications without the hassle of managing multiple passwords.

Technical Terms:

IdP (Identity Provider): Manages user authentication, enabling a single login to access multiple applications without re-entering credentials. It securely stores credentials and issues authentication tokens.

SP (Service Provider): The application or website that validates the token and grants user access.

CAS (Central Authentication Service) is a protocol and implementation platform.

• As a Protocol: defines a way for web applications to perform single sign-on (SSO). The protocol outlines how to authenticate users, issue tickets, and verify those tickets to provide access to various services.
• As a Platform: There are implementations of the CAS protocol, such as the open-source CAS server, which provides a complete system for managing authentication and single sign-on capabilities. These implementations offer tools and libraries for integrating CAS with your applications. So, when referring to CAS as a platform, it usually means the software or system that implements the CAS protocol to provide single sign-on services.

Advantages

• Security: SSO enhances security by reducing the number of passwords users need to remember. With fewer passwords, there’s less risk of weak passwords being used. Additionally, SSO systems often integrate with multi-factor authentication (MFA), adding an extra layer of protection.
• Simplification for Users and IT: SSO simplifies the login process reducing the frustration of managing multiple passwords. For IT teams, single sign-on (SSO) reduces the amount of technical support needed for password resets and user access management.
• Increased Productivity and Time Efficiency: With Single Sign-On (SSO), users save time by logging in once, allowing them to quickly access and switch between applications without repeated logins. This streamlined access reduces delays in work processes, leading to greater productivity.
• Centralized Control: IT departments gain centralized control over user access, making it easier to enforce security policies, manage permissions, and revoke access when needed. This centralization simplifies compliance with regulatory requirements.
• Usage Statistics: SSO offers valuable insights into application usage patterns. IT teams can monitor which applications are accessed, when, and by whom.

Disadvantages

• Security Vulnerabilities: If a user’s SSO credentials are compromised, it could result in unauthorized access to all connected applications. This makes robust security measures, like multi-factor authentication (MFA), essential.
• Supplier Dependency: If the SSO service experiences downtime or a breach, it could disrupt access to all connected applications, impacting business operations.
• Compatibility: Not all applications or systems may be compatible with SSO. Integrating legacy systems or specific third-party applications with an SSO solution can be challenging and require additional customization or development work.
• Complexity: Implementing SSO can be complex, especially in large organizations with numerous applications and systems. Integrating all these systems into a single sign-on solution requires careful planning, configuration, and ongoing management to ensure it functions smoothly.
• Costs: Although SSO can lead to long-term cost savings, the initial setup costs can be high. You’ll need to buy the SSO software or service, connect it to your current systems, and train your IT team to use and maintain it. Plus, there may be ongoing costs to keep using the SSO service.

Essentials of implementing SSO

SSO functions by separating authentication from the application, and delegates this task to an independent component dedicated to user authentication known as CAS (Central Authentication Platform).

The implementation process may vary based on specific company requirements and the following influencing factors:

1. Systems and Architecture: If you have a diverse environment with various systems and applications developed in different languages. You will need to determine how each application will connect to the SSO system and probably they will need custom development. This is because you must ensure they are compatible with SSO integration.
2. Database Collections: Once the SSO system is up and running, the applications no longer need to store or manage passwords. The applications rely on the SSO system to authenticate users. All SSO systems have a database collection known as Identity Store where the data will be stored and managed e.g., Active Directory, LDAP, a custom user database.
3. Roles and Permissions: In a Single Sign-On (SSO) environment, handling roles and permissions can vary depending on how they are structured within the applications and whether you want to centralize them or keep them independent.
   1. Centralizing Roles and Permissions in the IdP: The Identity Provider (IdP) manages and stores user roles and permissions, including this information in an authentication token (e.g., JWT). Applications A and B use the token to determine user access to actions and resources. This requires a unified roles and permissions model that is acceptable to all applications.
   2. Delegating Roles and Permissions to the Applications: The IdP only authenticates users and issues a token with their identity. The applications will continue to manage their roles and permissions internally based on the user identity they receive in the token. The token might include a user identifier or basic roles, and the application decides how to map that data to its roles and permissions.
4. Security Considerations: Ensuring secure communication between the SSO system and all integrated applications, handling token expiration and renewal, and protecting against various security threats all require careful planning and implementation.

Example

Here’s a high-level workflow for implementing Single Sign-On (SSO) with access to multiple applications (A, B, and C) through a CAS

1. The user enters their credentials on the SSO provider’s login page.
2. The SSO provider verifies the user’s credentials against its identity store.
3. Upon successful authentication, the SSO provider generates an authentication token (e.g., OAuth token, SAML assertion).
4. The user now has access to a catalog of applications he can access with the authentication token.
5. The user selects the application from the catalog and automatically the authentication token is sent to the SSO provider for validation.
6. The SSO provider verifies the token’s validity and returns user information to the application.
7. The application grants the user access based on the validated token and associated user information.
8. If the user then attempts to access Application B or C, they are not prompted to log in again. Instead, the application checks the existing SSO session and verifies the token.
9. The user’s session is maintained across all applications. Logout from any application should end the session across all applications, depending on the SSO provider’s implementation.
10. When the user logs out from any application, they are redirected to the SSO provider to end the session. The SSO provider invalidates the session, and the user is logged out from all applications.