Christos Polydorou

This post has been triggered by a project that I'm currently working on that involves nginx and containers. As part of the nginx configuration, I had to create a certificate key pair that was going to be used in order to secure traffic towards nginx. The challenge I faced was to convert the PFX certificate that was handed to me by the Certificate Authority team to the format nginx understood. Considering that this was a process that I'd followed many times in the past (and also blogged about), I decided to update a Powershell module of mine named CPolydorou.Security in order to make the use of OpenSSL friendlier to the Windows administrator.  The four new functions that are included in the latest version ( 1.2.0 ) are: Export-ServerCertificateFromPFX Export-CertificateChainFromPFX Export-PrivateKeyFromPFX Decrypt-PrivateKey Let's go through them one-by-one to see how they can help! For the examples demostrated below, I've created secure string objects for the passphras...

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...