Regenerating expired vCenter SSL certificates

This posting is ~7 years years old. You should keep this in mind. IT is a short living business. This information might be outdated.

During a vSphere 5.0 > 5.5 upgrade I got this message:

The customer hasn’t installed CA-signed certificats, so the expired certificates are the out-of-the-box self-signed certificates. The certificates are valid for two (VirtualCenter 2.5) respectively 10 years (since vCenter 4.x), depending on the Version. The only way to continue the installation is to renew the certificates. After renewing the certificates, you can simply continue the setup due the fact, that the vCenter service is stopped at this point of the setup and it loads the new certificates during startup. It’s the setup which checks the validity of the certificates. KB1009092 describes in great detail what to do, so I will not repeat what is already written there. You should note, that you can’t use the ESXi busybox to renew the certificates. The necessary OpenSSL binary isn’t included. The KB articles recommends OpenSSL for Windows. I simply used my Linux root server. But you can also use a small Linux VM. After renewing the certificates for vCenter, Inventory server and Web Client I simply continued the setup and it ran without problems by. The deployment of CA-signed certifcates is planned.

I recommend to use CA-signed certificates. You need a CA (this can be your own CA) and the vCenter Certificate Automation Tool, which makes the deployment of your own certificates much more easy! There are a couple of excellent posts on this topic. Derek Seaman wrote an awesome four-part series about the usage of the vCenter Certificate Automation Tool. This posting of Craig Kilborn is also a good reference. Craig refers to other sources, like Michael Webster.

Dealing with certificates can bedifficult for unexperienced administrators. They have to clearly understand how certificates work, what the job of a CA is and how all works together. Don’t be a beginner and quickly deploy a CA, just because you need NOW CA-signed certificates. Just use the self-signed certificates for a couple of weeks and work out a CA design that satisfies the customers requirements. Maybe the customer can use a CA for other purposes. Be a trusted advisor, not Mr. Quick ‘n Dirty. ;)

Patrick Terlisten
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