From: nobody@soda.berkeley.edu
Date: Wed, 2 Jun 93 00:10:53 PDT
To: cypherpunks@toad.com
Subject: Another chaining utility
Message-ID: <9306020744.AA02666@soda.berkeley.edu>
MIME-Version: 1.0
Content-Type: text/plain


I am working on a utility I call "chain" which is inspired by
Karl Barrus's hopmail and related scripts.  I am sending this message
with the command:

chain -m -s "Another chaining utility" cypherpunks@toad.com caltech jarthur extropia soda

The "-m" means for chain to pipe its output into sendmail so that it
is actually sent (otherwise it just writes to standard out and you
have to arrange to mail it on your own).  The "-s" sets the subject
for the last leg of the message to the following arg.  Then comes the
destination address, then a list of remailer nicknames, which are just
substrings of the remailers, read from an initialization file.  This
message is passing through four remailers.

The "-m" feature is implemented only on Unix systems.  On DOS you
always get the output in a file and then send that however you
normally would.

I also have a "-e" switch which encrypts the message using a public
key looked up by the destination address.  Cypherpunks doesn't have a
public key so that's not appropriate here.  But if I wanted to send
an encrypted note to, say, Phil Zimmermann, I could just do:

chain -em prz@sage.cgd.ucar.edu portal mead
Hi, Phil, give me a call when you have a chance -- Hal
^D

and it would go via the Portal and Mead remailers, encrypted at each
step, and finally to Phil, encrypted with his public key.  Pretty
easy.

I couldn't get Karl's hopmail.bat to run on my PC (not enough environment
space?) so I wrote this in C and it works OK.

I'll be sending the code to Eric to be archived in a few days.  If
anyone has any wish lists for features I will be glad to try adding
them.

(I am composing this on a Unix system in order to demonstrate the -m
switch, so I can't cleartext sign as I normally would.  I am in the vi
editor and I am sending the message with "1G!G", which tells vi to
pipe the whole file into a command, followed by the "chain" command
line above, verbatim.  That's all there is to it.)

Hal Finney
74076.1041@compuserve.com