Greetings to all you geeks out there! It's a pleasure to have you here at geekcoding101.com! With almost 20 years immersed in the vibrant world of Linux and security domain, I've encountered a myriad of tools and technologies that have shaped my journey. Today, I'm excited to introduce you OpenSSL and Certutil—two indispensable utilities that play pivotal roles in managing digital certificates and encryption. Whether you're safeguarding your web servers or securing communications, understanding these tools is crucial. I've distilled my insights and tips into this post, aiming to arm you with the knowledge to leverage these powerful utilities effectively. Enjoy! Openssl OpenSSL is an open-source software library that provides a robust, commercial-grade, and full-featured toolkit for SSL and TLS protocols, as well as a general-purpose cryptography library. It is widely used by internet servers, including the majority that implement secure web (HTTPS) connections, as well as in countless other security-sensitive applications. Here are some key aspects of OpenSSL: Core Features Query Information Query on Private Key: openssl rsa -in privatekey.pem -check Query All Information: openssl x509 -in certificate.pem -text -noout Query Subject: openssl x509 -in certificate.pem -subject -noout Query Validity: openssl x509 -in certificate.pem -dates -noout Query Purpose: openssl x509 -in certificate.pem -purpose -noout Example: Certificate purposes: SSL client : No SSL client CA : Yes SSL server : No SSL server CA : Yes Netscape SSL server : No Netscape SSL server CA : Yes S/MIME signing : No S/MIME signing CA : Yes S/MIME encryption : No S/MIME encryption CA : Yes CRL signing : No CRL…