steam prpl?

Gary Kramlich grim at
Sun Dec 2 01:47:41 EST 2007

Hash: SHA1

Mark Schneider wrote:
> On Nov 13, 2007 2:34 AM, Ryan Barrett <pidgin at> wrote:
>> hey all. does anyone know anything about the steam ( )
>> IM protocol? i've been spending more and more time on steam lately, and i'd
>> love to use pidgin instead of their client when i'm not actually in a game.
>> i haven't found much with web searches. the most useful so far is this page on
>> their developer wiki, which seems to imply that it's msn:
>> anyone know more?
>> -Ryan
> Ryan,
> I saw your message a while back, and i've been curious about the Steam
> Friends protocol myself.  They don't use MSN: the link you reference
> is for people to submit ideas for improvement of Steam Friends to the
> developers.
> I finally got around to analyzing the Steam protocol this weekend, and
> this is what i'm finding:
> -Uses UDP running on port 27017 (although previous versions used 27013
> and 27014, so maybe they just bump the port# when they change
> protocols).
> -Uses RSA (or very similar encryption) scheme to transmit messages.
> They use the CryptoPP library for this.
> -Each message contains a 36-byte header beginning with the string
> "VS01" followed by 32-bytes that determine what type of message it is.
> Best guesses:
> bytes 0-3: "VS01"
> bytes 4-7: type of message
> bytes 8-11: destination ID
> bytes 12-15: source ID
> bytes 16-19: id/sequence#1
> bytes 20-23: iid/sequence#2 (looks like which id this packet is responding to)
> bytes 24-27: 0, 1, or 2 are all i've seen so far.  No idea.
> bytes 28-31: id/sequence#1 or id/sequence#1+1 (if contains remainder
> of data from previous split packet)
> bytes 32-35: length (of whole packet, even if split)
> I'm going to do some more poking around, but unfortunately i'm not as
> educated on encryption as i would like to be (i understand the Alice
> and Bob story [1], but that's about it).
> -Mark
> [1]

Last I checked, the encryption was ice-key or whatever.  I can't
remember and that was eons ago.  I may still have some of my work
around, if I do I'll let you know.

- --
Gary Kramlich <grim at>
Version: GnuPG v1.4.6 (GNU/Linux)
Comment: Using GnuPG with Mozilla -


More information about the Devel mailing list