Converting Certificates using OpenSSL
Certificates are an integral part of every IT infrastructure and service since they can be used to encrypt data, secure the communications, verify identities and provide trust. In this article I'm going to demonstrate a number of conversions you may have to perform in order to prepare a certificate to be imported to a system. Before moving on to the actual part about the conversion, a few words about the certificates and their file extensions. Encodings There are two different kinds of encoding for an X509 certificate, DER and PEM. DER encoded files are binary in contrast to PEM which are Base64 encoded and human readable. File Extensions The most commonly used file extensions for certificate and key files are: .crt - Used for certificates in DER or PEM format. .cer - Also used for certificates, alternative to crt .key - Used for private key files .pfx - Used for certificate and private key bundles. Used different format from the others (pkcs12) Conversion When it co