Attacking and Defending Active Directory with OpenSSL: TLS, Certs, and Smartcard Chaos"

Active Directory environments depend heavily on TLS and X.509 certificates—yet few defenders look at them through the lens of OpenSSL, the Swiss Army knife of cryptographic analysis. Whether it's LDAP over SSL (LDAPS) or certificate-based Kerberos authentication (PKINIT), small certificate misconfigurations can lead to major security exposures. In this talk, I’ll discuss how to use OpenSSL as your primary tool for breaking, auditing, and hardening Active Directory’s certificate trust chains. We’ll walk through how attackers can abuse weak certificates and TLS configurations using OpenSSL, and how defenders can use those same tools to shut it down. From real-time LDAPS probes to parsing malicious Kerberos smartcard certs, this session will show you that OpenSSL isn’t just for developers—it’s a penetration tester’s scalpel and a defender’s stethoscope.