You can pretty much answer your own question: see http://wiki.wireshark.org/Tools.

Or, you could read up on how https works... which -- oversimplified -- means it and the user's agent negotiate a session key (ie, encryption element) BEFORE data like passwords is sent over the wire. For slightly more precise info, check http://en.wikipedia.org/wiki/HTTP_Secure (or, better yet, read the authoritative docs).

Update: Borked link to the wireshark tools wiki page fixed. Thanks, erix, for the heads up!