tcpdump/snort to capture chat sessions

[John-Mark Gurney]

Tom Judge wrote this message on Wed, Jun 11, 2008 at 15:01 -0500:
> Bill Moran wrote:
> >In response to R J <rjohanne at wnk.hamline.edu>:
> >
> >>I am trying to use tcpdump (or snort, but they are both behaving the same 
> >>in this case) to capture all the lines or contents of an msn 
> >>chat session, the actual conversation.  I am getting partial output; i.e, 
> >>I'll only get half of a sentence, and I don't see the rest of the lines. 
> >>And ofcourse, alot of it seems to be hex or obfuscated html?
> >>
> >>What switches do I need to capture the entire lines of text?
> >
> >Don't know about snort, but with tcpdump use -s0
> >
> This is a good start however you are not guaranteed to see the whole 
> chat message in a single TCP packet.  If you are looking for something 
> more advanced you will have to write a program around pcap/bpf or 
> similar to read the TCP stream.

such as tcpflow which read tcpdump streams and outputs each TCP byte
stream...

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."