Which is the best method to implement a new SSO solution to capture the SSO header?

Creating a hook plugin that implements a servlet filter is the best method for implementing a new Single Sign-On (SSO) solution to capture the SSO header. This approach allows developers to extend and customize Liferay’s functionalities without altering the core source code of the portal.

By using a hook plugin, you can add additional functionalities, such as a servlet filter, that can intercept the request before it reaches the main application logic. This is especially useful for SSO implementations, as it allows you to access the incoming request headers and extract the necessary SSO information for authentication.

Hook plugins are designed to modify or extend the behavior of existing Liferay components while ensuring that updates to the Liferay platform do not overwrite customizations. This encapsulation makes maintenance easier and keeps the upgrade path clean, avoiding potential issues that can arise from direct modifications to the portal source code.

In contrast, creating an Ext plugin often involves changes at a deeper level of the framework, which can complicate future upgrades and maintenance. Modifying the portal's source code directly can lead to similar issues, making it challenging to integrate updates and patches. Creating an override for the Struts action is not as direct for capturing headers, as it pertains to a different layer of request handling