Although all certificates can be issued by the single Root CA authority, you will sometimes have a need to make a Subordinate (or Intermediate) CA authority. In most cases, this is related to the increased security needs or higher flexibility.
My articles related to the OpenSSL tool. How-to guides related to both the certificate generation process and usage on different platforms.
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!
How to create a Root CA certificate using a request file
Today, I want to share with you another exciting story related to certificates and OpenSSL. I will answer on the tricky question – how to renew a Root CA certificate.
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