I have a Win Server 2008 R2 server running IIS. I am using ACME with Let’s Encrypt to try and install multiple certificates on my server. I had the operations team add CAA records to the DNS to allow for letsencrypt.org as the main uwo.ca uses Thawte.
The first certificate installed fine to ssts.uwo.ca. I installed a few others before I noticed that things weren’t working correctly. To complicate things, I have an existing Thawte certificate for one of the sites which is sscsecure.uwo.ca with a SAN for sociology.uwo.ca. The Thawte certificate stopped working and I noticed that always, only the most recent site worked with the let’s encrypt certificate. When I investigated further, I noticed that if the last certificate I installed was for ssc.uwo.ca, then all the previous certificates that I installed were changed to the ssc.uwo.ca, instead of ssts.uwo.ca.
At this point, I have removed all the let’s encrypt certificates and got the sscsecure.uwo.ca cert working again (unfortunately, the SAN for sociology.uwo.ca is not working).
Is there a way to get this working for each site without overwriting the certificates for other sites?