From: Timothy Newsham <newsham@wiliki.eng.hawaii.edu>
Date: Sun, 21 Nov 93 17:43:21 PST
To: sameer@uclink.berkeley.edu
Subject: Re: Does someone know about irc "/on"?
In-Reply-To: <m0p1Mhd-000J6pC@infinity.hip.berkeley.edu>
Message-ID: <9311220143.AA28056@toad.com>
MIME-Version: 1.0
Content-Type: text/plain



I wrote a package for doing encryption over irc called Circ.  It was posted
to comp.sources.misc and should be in the archives.  It is currently not
extremely secure,  the weakest link is the random key generation which is
seeded by the time.  This is very easy to brute force if you have any
information on the time (even if you know the time to within a year).
The program uses RSA to exchange secret keys and uses tripleDes to encrypt
messages.  

The program is implemented as a binary written in C and talks to ircII through
/on's and /alias'es.  The script used by Circ is included below and may
give you some ideas on how to interact with ircII.





# this is for ircII 2.2.4
# for some reason, /on ^public acts differently

# Start up the proggie
/^exec -name crypt exec new

# automatically pick out protocol messages
#    crypt processor gets:   !send nick!CLIPPER:...etc
#    or   !our nick!SKPJACK:...etc 
# under 2.2.4 public has:  nick channel message
#   the version I use has  nick message
#   this is the difference between the two script versions
/on ^public "* * CLIPPER:*" /msg %crypt !$0!$2-
/on ^public "* * SKPJACK:*" /msg %crypt OURNICK:$N;/msg %crypt !$0!$2-
/on ^public_other "* * CLIPPER:*" /msg %crypt !$0:$1!$2-
/on ^public_other "* * SKPJACK:*" /msg %crypt OURNICK:$N;/msg %crypt !$0:$1!$2-

/on ^msg "* CLIPPER:*" /msg %crypt !*$0*!$1-
/on ^msg "* SKPJACK:*" /msg %crypt OURNICK:$N;/msg %crypt !*$0*!$1-

# messages comming back from crypt, to server or screen?
/on ^exec "crypt TCHANNL: *" /msg $C $2-
/on ^exec "crypt TSCREEN: *" /echo $2-
/on ^exec "crypt TNICKNM: *" /msg $2 $3-

# our irc commands:
#    /key nick  or /key nick filename
#    /die
#    /e message to be encrypted
#    /p message to be plaintext
#    /crypt   (turn on automatic encryption)
#    /plain   (turn off automatic encryption)
#    /emsg nick text  send an encrypted message
/alias key /echo K->*$0* Sending Key;/^msg %crypt SENDKEY: $0-
/alias die /^msg %crypt QUITDIE:;/query 
/alias e /echo E> $0-;/^msg %crypt CRYPTME:$0-
/alias p /msg $C $0-
/alias crypt /query %crypt
/alias plain /query
/alias emsg /echo E->*$0* $1-;/^msg %crypt !$0!CRYPTME:$1-

/echo *** Encrypted Irc Protocol loaded.