Single Sign On | Identity And Access Management

Introduction to Single Sign-On

Single Sign-On (SSO) is an authentication process that allows a user to access multiple applications with one set of login credentials, such as a username and password. This eliminates the need to remember multiple usernames and passwords, and it simplifies the user experience by reducing the frequency of logins.

Benefits of Single Sign-On

Single Sign-On offers several benefits, including:

Improved user experience by reducing the need for multiple logins.
Enhanced security through centralized authentication.
Reduced IT costs by lowering the number of password reset requests.
Streamlined access management.

How Single Sign-On Works

SSO works by using a trusted identity provider (IdP) to authenticate users. Once authenticated by the IdP, users are granted access to various applications without needing to log in again. The typical SSO process involves the following steps:

The user attempts to access a protected application.
The application checks if the user is already authenticated.
If not authenticated, the user is redirected to the IdP.
The user provides their login credentials to the IdP.
The IdP authenticates the user and generates a token.
The user is redirected back to the application with the token.
The application validates the token and grants access to the user.

Implementing Single Sign-On

To implement SSO, you need to set up an IdP and configure your applications to trust the IdP. Below is an example of how to implement SSO using SAML (Security Assertion Markup Language) with an IdP like Okta.

Example: SSO with SAML and Okta

In this example, we will configure SSO for a web application using SAML and Okta as the IdP.

Step 1: Set Up Your Okta Account

First, sign up for an Okta account at https://www.okta.com/. Once you have an account, log in to the Okta admin console.

Step 2: Create a SAML Application in Okta

In the Okta admin console:

Go to Applications and click on Add Application.
Select Create New App and choose Web as the platform and SAML 2.0 as the sign-on method.
Click on Create and fill in the application details.
In the SAML Settings, provide the following information:
- Single Sign-On URL: The URL where your application receives the SAML response.
- Audience URI (SP Entity ID): The unique identifier for your application.
Click on Next, review the settings, and click on Finish.

Step 3: Configure Your Web Application

In your web application, you need to configure it to trust the Okta IdP. This typically involves:

Importing the Okta IdP metadata XML file into your application.
Configuring your application to use the Okta IdP for authentication.

Below is an example configuration for a web application using Spring Security and SAML:

<bean id="samlWebSSOFilter" class="org.springframework.security.saml.SAMLProcessingFilter">
    <property name="authenticationManager" ref="authenticationManager" />
</bean>

<bean id="metadata" class="org.springframework.security.saml.metadata.CachingMetadataManager">
    <constructor-arg>
        <list>
            <bean class="org.springframework.security.saml.metadata.ExtendedMetadataDelegate">
                <constructor-arg>
                    <bean class="org.opensaml.saml2.metadata.provider.ResourceBackedMetadataProvider">
                        <constructor-arg>
                            <bean class="java.util.Timer" />
                        </constructor-arg>
                        <constructor-arg>
                            <bean class="org.opensaml.util.resource.ClasspathResource">
                                <constructor-arg value="metadata/okta-idp-metadata.xml" />
                            </bean>
                        </constructor-arg>
                    </bean>
                </constructor-arg>
                <constructor-arg>
                    <bean class="org.springframework.security.saml.metadata.ExtendedMetadata" />
                </constructor-arg>
            </bean>
        </list>
    </constructor-arg>
</bean>

Testing Your SSO Implementation

Once your application is configured, you can test the SSO implementation by attempting to access the protected application. You should be redirected to the Okta login page for authentication. After a successful login, you will be redirected back to the application with access granted.

Conclusion

Single Sign-On simplifies the authentication process, enhances security, and improves user experience. By following the steps outlined in this tutorial, you can implement SSO for your web applications and leverage the benefits of centralized authentication.

Single Sign-On (SSO) Tutorial