OpenSSL asn1parse: How to Decode and Troubleshoot ASN.1 Data Overview Certificates, certificate signing requests, private keys, CRLs, and many other PKI objects are built from ASN.1 data structures. Most system administrators do not need to inspect those structures byte by byte during normal … [Read more...] about OpenSSL asn1parse: Decode Certificates and ASN.1 Data
How to Create a Private CA with OpenSSL CA.pl
Overview System administrators frequently need TLS certificates for systems that are not publicly accessible (and can leverage OpenSSL CA.pl as a solution), including: A public certificate authority may not be appropriate for these systems, especially when their hostnames are only resolvable … [Read more...] about How to Create a Private CA with OpenSSL CA.pl
Certificate Transparency Monitoring
With the certificate transparency (CT) enforcement by Chrome, all publicly trusted TLS certificates are now logged in a distributed manner to multiple CT logs which brings us to discuss certificate transparency monitoring. The irony here is that while a PKI is based on trust, you cannot trust it … [Read more...] about Certificate Transparency Monitoring
PKI Weekly Watch: OpenSSL Security Fixes to Review
Opening summary This PKI Weekly Watch reviews still-relevant OpenSSL security fixes from June 2026 the release of OpenSSL 4.0.1, which patches seven security vulnerabilities discovered in recent months. These issues range from heap buffer over-reads to memory corruption and affect multiple OpenSSL … [Read more...] about PKI Weekly Watch: OpenSSL Security Fixes to Review
Verify Certificate Chains with OpenSSL
Verifying certificate chains is one of the most common troubleshooting tasks when diagnosing TLS and SSL connection issues. If a certificate chain is incomplete or incorrectly configured, clients may fail to establish a trusted connection. This guide explains how to verify certificate chains with … [Read more...] about Verify Certificate Chains with OpenSSL
EV Certificates – Extended Validation Certificates
Question: What are EV Certificates? Answer: Extended Validation (EV) Certificates are SSL Certificates that are issued after a rigorous validation process. The cryptographic strength and security of an EV certificate is no different than that of a DV (Domain Validated) or OV (Organization … [Read more...] about EV Certificates – Extended Validation Certificates
How TLS and PKI Work (Explained for DevOps Engineers)
This lesson explains how TLS and PKI work in practical terms for DevOps engineers. Understanding how certificates, certificate authorities, and trust chains function is essential when troubleshooting TLS errors or designing secure infrastructure. This article is part of the PKI for DevOps … [Read more...] about How TLS and PKI Work (Explained for DevOps Engineers)
Understanding X.509 Certificates (Fields, Extensions, and SANs)
This lesson explains the X.509 certificate format in practical terms for DevOps engineers. If you have ever opened a certificate in OpenSSL, Java keytool, or a browser and wondered what all the fields mean, this guide will help you understand the most important parts. This article is part of the … [Read more...] about Understanding X.509 Certificates (Fields, Extensions, and SANs)