Project: txsdpy

published: 08 Feb 2012 | tags: txspdy

A ShRUG this week someone mentioned a guy who was working a project every night and blogging about the progress he was making. He was up to 200+ days of this. I thought I'd try to do the same.

So first project: txspdy - a python twisted implementation of a SPDY server.


  1. knowing http has helped in my day job and protocols are fun. XMPP hacking was a lot of fun.
  2. new shiny
  3. websockets over spdy sounds awesome. I've used websockets to build a app UI for a DirectConnect client I've written.

Why hasn't anyone else done this yet?

There is a python prototype linked off the SDPY page, but it's doesn't use twisted. I will, no doubt, be reading over that code. The fun thing is that no one knows if SDPY will take off.

First problem:

SPDY uses a new SSL extension to tell connecting clients what protocols the server can speak. OpenSSL has a beta version that implements this extension, but you can't use it via pyopenssl. So I've checked that out and started hacking on the C code for it.

I wanted to test that I could get Chrome to talk SPDY to a test server before I went much further. First thing you need are some real ssl certs. I had some from StartCom. I used the openssl binary like this:

/usr/local/ssl/bin/openssl s_server -key server.key \
   -cert server.crt -accept 9000 -www -nextprotoneg spdy/2,http/1.1 -debug

My first attempts with a self signed cert resulted in Chrome connecting and stopping the ssl handshake 3 times then using http/1.1 even thought I had spdy listed too. Not sure what the purpose of that was.