I’m quite sure that -p is needed. The “remote” end as far as ssh is concerned, is the machine on which it is invoked. That is, my work machine, where I am running ssh, is the remote end, and as such, “ssh -p 12345 localhost”.
In other news, I finally managed to get this to work! It occurred to me that corkscrew and/or proxytunnel (proxytunnel.sourceforge.net) can be made to work if we use a super-server like inetd to spawn them. This also circumvents the “lack of multiplexing connections” problem that I ran into. So I downloaded and compiled proxytunnel, which tunnels a connection into an interactive session through an HTTPS tunnel.
Then I added an entry in inetd for daap: “daap stream tcp nowait root /usr/bin/tcpd /usr/local/bin/proxytunnel -g myproxy -G proxyport -d myip -D 3689.
With proper publishing through mdnsresponder, I could now open multiple streams and listen to music!
Next question: Given my limited bandwidth and my frequent use of heavy-bitrate mp3’s, can I downsample mp3’s on the fly through mt-daapd to conserve bandwidth?