How to make a certificate request from an existing Root CA certificate

Many times, you will quickly make your Root CA certificate following the instructions in this post. After a while, such Root CA certificate will expired and all issued certificates will be useless.

However, my friends, you don’t need to start from scratch. All you need to do is to renew your Root CA certificate. Oh yes, I know! You can’t extend it as you don’t have its certificate request file…

You can make it from an existing Root CA certificate. Let’s do it!

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How to generate a certificate for a mobile device

For years, my focus has been on server certificates. I recently made a few simulation which reopened  the old question – how to make a certificate for a mobile device? Such device can be a Windows computer (either desktop or laptop), but also an Android or iOS device.

It took a while to collect all pieces together. I solved the riddle and I bring you this wonderful story. Continue reading

PEM, CER, DER… what’s that?

And don’t forget PFX, P12, and so on. Sooner or later, you will face the challenge that one system requires a PEM certificate, other (especially those Windows based) requires PFX, etc.

Although all that sounds complicated, actually it isn’t. All those files are the different forms of the same security certificate. Continue reading