Are you saying about a certificate or about the actual data exchanged with server-side location software? I recently came across this article while acomplishing something at work, maybe mitmproxy could be used to "fool" N900 that your computer is location server (may require fake certificate generation via mitmproxy and installation on N900) and passing all traffic through your set-up proxy? That could help in debugging the internals of raw unciphered data exchanged between N900 and location server... I hope that's helpful (but I'm awake for 20-something-th hour now, so please excuse me if I got you wrong).