Wow, what a horrible weekend it has been dealing with all these certificate expirations (both clients, and my own). Ton’s of articles on the internet, however tons don’t cover what you do if you have your own certificate authority and DON’T want to use a self-signed certificate. Also, all the tutorials on the net use the Shell, I rather use the GUI…
When it comes time to renew your certificate, you’ll be seeing these in your Event Viewer:
Event ID: 12018
User (If Applicable): N/A
Computer: server.domain.com Event Description: The STARTTLS certificate will expire soon: subject: server.domain.com, thumbprint: ZOMGZOMGZOMGZOMGZOMGZOMGZOMGZOMG, hours remaining: 664. Run the New-ExchangeCertificate cmdlet to create a new certificate.
Event ID: 12017
User (If Applicable): N/A
Computer: server.domain.com Event Description: An internal transport certificate will expire soon. ZOMGZOMGZOMGZOMGZOMGZOMGZOMGZOMG, hours remaining: 664 Event Log Name: Application Event Log Type: error
Anyways, first off, DO NOT use this tutorial if your running “Microsoft Small Business Server”, there is a better, easier, and more automated way to perform this on SBS (I won’t be covering that in this blog post, I will however make another one to explain the procedure). Depending on you’re environment, this may or may not be the best way or the right way to do this. In my environment, I have 1 server that acts as a Domain Controller and a Certificate authority, and a second server that is running Microsoft Exchange 2010.
You take your own risk if you perform the instruction in this blog post.
1) Start the renewal process
We need to generate a renewal request. Load up the Exchange Console, and select the “Server Configuration” on the left. It should load up your Exchange Certificates on the lower half of your screen. Look for your certificate that is about to expire. To get the details on the certificates, simply double click and it will load the info, if you’re unsure of which certificate it is, use the thumbprint provided in the Event viewer, and compare it to the Thumbprint on the “Details” tab of the certificate. Once you find it, highlight it and select “Renew Exchange Certificate…” on the action pain to the right.
Renew Exchange Certificate
2) Create renewal request Wizard
This will open the certificate renewal request wizard (as shown below):
Certificate Renewal Request Wizard
Simply choose a file name and location to save the request. It’s easiest just to save it on your desktop. After, hit “Renew”. This will generate the certificate renewal request.
3) Copy certificate request to clipboard
Locate the file you created above inside of Windows Explorer. Right click on this file and select “Open”, or “Open With”. When prompted, uncheck the “Always use the selected program to open this kind of file” option, and select “Notepad” as the program to open the file with. Example below:
Open with Notepad
This will open the certificate request. Now highlight all the text and copy it to your clipboard. Example below:
Certificate request in Notepad
4) Submit certificate request to certificate authority using web interface
Now we submit the request! Log on to your certificate authority web interface. On the first screen, we will select “Request a certificate”, as shown below:
Then select “advanced certificate request”, as shown below:
Advanced certificate request
And now, choose “Submit a certificate request by using a base-64 encoded CMC or PKCS #10 file, or submit a renewal request by using a base-64-encoded PKCS #7 file.”, again example below:
Finally, we are going to populate the request. Inside of the “Saved Request:” text box, paste your request from your clipboard (which we copied to your clipboard above), then for “Certificate Template:” choose “Web Server”. Example is below:
Now select Submit! On the next page that loads, simply select “Download certificate” and save it to a location you’ll remember.
5) Install certificate on Exchange
We now have a certificate that’s ready to be installed. Go back to the Exchange console where we left off. Inside of the certificate list, you should see an item that has a status that says something about a pending request. Highlight this request, and on the Action Pane, select “Complete request”. I could be wrong on what this says as I can’t remember and did not take screenshots.
A wizard should open up, in this wizard simply point it to the new certificate (the file we just saved at the end of step 4, shown above). Follow the instructions.
6) Assign Services to Certificate
Now that the certificate is installed, we need to assign which services will use it. The new certificate should also now be in the list of certificates inside of Exchange. Highlight the new certificate, right click, and select “Assign Services to Certificate”. Example below:
Assign Services to Certificate
Once the wizard opens up, follow through and when actually prompted for the services check everything except for “Unified Messaging”. Finish the wizard.
7) Delete old certificate
Now we are almost done. Go back to the certificate list inside of Exchange and look for the old certificate that is going to expire. Highlight it, right click, and select “Remove”.