To .key and to .pem

At my company, everyday I’ve work with public and private keys. Idea with this key is very simple: I have got one key(private), clients gets another(public). Two keys works only together, a third doesn’t exist.

Where did I used that? For example with https. I need .pem and .key files. PEM includes certificate and KEY include private (usually RSA) key.

But what if client give me another files, like .pfx, crt, csr…? How to live with it?

Below, I give you a little review of this conversion (for more inspiration). Continue reading →