I have a Comodo supplied "star" certificate ie it has a subject name of *.example.com. This is handy for multiple websites. Here are some notes on usage.

During the installation you need to supply the certificate in PEM format. However you may have it in two files (.crt and .key or similar) or as a PKCS12 (.pfx) format.

It needs to look like the following:

random stuff
random stuff

So, if your certificate is supplied with headings like the above then just cat the two together and put .pem on the end.

This fixes up the sync service itself.

There are several other certs in use as well eg the one for the admin site.

# find /var/lib/datasync -name "*.pem"

Simply (backup the file first!) replace the webadmin/server.pem contents with the new details. Then:

#/etc/init.d/datasync-webadmin restart

My personal phone is a Nokia N86 and it does not have Comodo listed as a CA. Bugger. To fix that I created a DER file of the Comodo root certificate bundle, put it on a web server and browsed to it. I then was able to put it into the trusted root store on my phone.

This command converts the bundle to DER:

$openssl x509 -outform der -in STAR_example_com.ca-bundle -out STAR_example_com.ca-bundle.der

You may not have to do this if you already have it in DER format.

Incidentally you can use certmgr or the certificates mmc to do similar jobs on a Windows thing.

Hope the above helps someone to get going.