Secure Filter should never be disabled

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: Master
• Fix Version/s: 7.0.0 DXP FP12, 7.0.0 DXP SP2, 7.0.3 CE GA4, 7.1.X, Master
• Component/s: Application Security
• Labels:
  • liferay-digital-enterprise-70-sp2
  • liferay-fixpack-de-12-7010
• Branch Version/s:
  7.0.x
• Backported to Branch:
  Committed
• Fix Priority: 3
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/46911

According to following comment, SecureFilter must not be disabled due to security reasons, see: https://issues.liferay.com/browse/LPS-60491?focusedCommentId=699220&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-699220

Steps to Reproduce:

1. Use com.liferay.portal.servlet.filters.secure.SecureFilter=false on portal-ext.properties
2. Start Liferay Portal
3. Log in

Expected results:
Login should be successful.

Current results:
Caused by: com.liferay.portal.kernel.security.auth.PrincipalException: Principal is null appears.