Web-based single sign-on can enable a user to log in to a single interface (such as through a web browser or thin client) and then provide SSO services to the user for one or more web applications. The web-based SSO system can be extended to support one or more different access control methods, such as form-fill, Federated (OIF), SSO Protected (OAM), and other policies. The web-based SSO system can include a user interface through which the user can access different web applications, systems, etc. and manage their credentials. Each SSO service can be associated with a web interface allowing the SSO services to be accessed over the web. The web interfaces can provide CRUD (create, read, update, delete) functionality for each SSO service. To support different access policy types, the web-based SSO system can include an extensible data manager that can manage data access to different types of repositories transparently.