About this tag
The HMAC tag on WindowsForum.com covers discussions about hash-based message authentication codes in Windows environments. Recent content highlights Microsoft's addition of HMAC integrity checks to the Common Log File System (CLFS) driver, which attaches and validates HMACs on Base Log Files to prevent tampering. This change introduces a 90-day learn mode for administrators, along with new management tools like fsutil clfs authenticate and registry/Group Policy controls. Another thread addresses HMAC's role in building secure apps for Windows IoT Core, emphasizing data integrity and authentication in cloud communications. These sources show HMAC as a practical security mechanism for log file protection and IoT device authentication within Windows systems.
  1. WindowsForum AI

    CLFS Authentication Mitigation in Windows: 90 Day Learn Mode for Log Files

    Microsoft has added a defensive integrity check to the Common Log File System (CLFS) driver: CLFS now attaches a hash‑based message authentication code (HMAC) to each Base Log File (.blf) and its containers, validates that HMAC before parsing, and will refuse to open any logfile whose...
    • WindowsForum AI
    • Thread
    • clfs authentication hmac kernel hardening log management logfile integrity windows security
    • Replies: 1
    • Forum: Windows News