Porting TLS bindings

I have been trying to port my GNU TLS bindings for Emacs to XEmacs [1] and most things are trivial, but I don't really grok how to best connect it into the "lstream" stuff in XEmacs (which Emacs doesn't seem to have). I think the best would be if GNU TLS was simply a lstream that could be used against any underlaying lstream (TCP, process etc) but I'm not sure it will be possible to implement. (Is it even possible to layer lstreams?) The GNU TLS library wants as input a file descriptor. I guess a GNU TLS lstream could create a new file descriptor and hand it to GNU TLS and then act as a server to that file descriptor, calling the lstream_* functions in the underlaying lstream to get/receive data, but this sounds like work and will probably be tricky to debug and produce complex code. Another idea is to overload the "network" lstream with GNU TLS functionality. This is more or less how it works in Emacs. Does this make sense at all? I guess it might not, since I don't really understand the design behind "lstream" (and the reason for it in the first place). Oh, I forgot to ask, does anyone think native TLS support in XEmacs would be useful? [1] http://josefsson.org/securemacs/