I have a document attempting to fetch content from, say, https://content.website.com. The certificate in use is for www.website.com, but lists content.website.com as a valid subject alternative name.

Does Prince not understand Subject Alternative Name in certificates?

Prince uses curl for HTTP access, which should handle certificates properly. What error message are you getting, and do you get the same error if you run curl from the command-line?

You are correct, curl also seems to have a problem. I'll go fix my stuff. Thanks!