Insights from the QCecuring

Fix the 'self signed certificate in certificate chain' error in OpenSSL, Node.js, curl, Git, and npm. Covers internal CA trust, corporate proxy CAs, and proper trust store configuration.

Fix the SSH 'Host key verification failed' error. Covers removing old keys, verifying new fingerprints, StrictHostKeyChecking options, and managing known_hosts at scale — with security warnings about MITM attacks.

Fix the SSH 'Permission denied (publickey)' error. Covers wrong key file, file permissions, SSH agent, authorized_keys issues, GitHub/GitLab, AWS EC2, and sshd_config — with ssh -vvv debugging.

Fix the 'unable to get local issuer certificate' error in OpenSSL, curl, Git, npm, pip, and Docker. Covers missing CA bundles, corporate proxies, and trust store configuration for every platform.

Master IIS SSL certificate binding — import PFX certificates, configure SNI, manage wildcard certs, automate with PowerShell, and fix common binding issues including disappearing bindings, port conflicts, and certificate dropdown problems.

The definitive reference for Java's cacerts trust store — locate it across JDK versions, list trusted CAs, import and remove certificates with keytool, configure custom trust stores, handle Docker containers, and troubleshoot PKIX path building failures.

Design hybrid PKI architecture combining on-premises AD CS with Azure services. Covers Intune certificate connector, Azure AD App Proxy for NDES, Windows Hello for Business, Intune Cloud PKI, and Azure Key Vault integration.

Understand AD CS certificate templates — versions V1 through V4, subject name handling, key usage, enrollment permissions, auto-enrollment, and how to prevent ESC1-ESC8 privilege escalation attacks through proper template configuration.

Step-by-step migration playbook from legacy Microsoft AD CS to modern PKI with ACME, HashiCorp Vault, and cert-manager. Covers assessment, parallel operation, workload migration, rollback plans, and realistic timelines.

Fix every common AD CS error — enrollment denied, template not available, RPC server unavailable, CRL failures, auto-enrollment not working, and certificate chain issues. Includes exact certutil commands and event log analysis.