A guide to detecting and troubleshooting SSL certificate problems with OpenSSL command line tools.
Historical SSL/TLS vulnerabilities such as Heartbleed, POODLE, and DROWN and security lessons learned.
Differences between SSL certificate file formats and format conversion commands with OpenSSL.
We explain step by step how to create the CSR file required to obtain an SSL certificate on different server types.
What is SSL/Certificate pinning and why does it fail? Pinning errors, certificate renewal problems and safe pin management guide in iOS and Android applications.
SSL certificate chain errors: Detection and solution of Incomplete chain, wrong order, expired intermediate problems.
SSL/TLS Handshake Failed error is when the handshake process fails while establishing a secure connection. Step-by-step solution to certificate, protocol and server configuration issues.