From: stewarts@ix.netcom.com
Date: Tue, 17 Sep 1996 11:03:18 +0800
To: an401dws@gold.ac.uk (Doug)
Subject: Re: New Remailers?
Message-ID: <199609161835.OAA01049@attrh1.attrh.att.com>
MIME-Version: 1.0
Content-Type: text/plain


At 10:53 AM 9/16/96 BST, you wrote:
>I recently secured an account with anon.penet and then a few days later got
>a post informing me that the servive was now terminated. Anybody out there
>know of any remailers where you dont have to have a Phd in computer science
>and a thorough working knowledge of PGP in order to operate?

Raph Levien's remailer list lives at
        http://www.cs.berkeley.edu/~raph/remailer-list.html
Most of the remailers on it are the one-way variety - you can send
mail to someone anonymously, but you don't get an address for
people to reply to you.  They're easy to use.

Some of them also support anonymous reply blocks,
which are a somewhat difficult-to-use feature - you basically PGP-encrypt
your return address (in the correct syntax), and tell anybody who wants
to reply to you to include the block at the beginning of their mail.

There have been some pseudonym servers besides anon.penet.fi,
which provide higher security, and are easier to use than anonymous
reply blocks, once you set them up (which generally involves creating
anonymous reply blocks :-)  Two of them have been spammed to death,
but the cyber remailer at alias@alias.cyberpass.net is still up.
Send it a request for help to get information.  Raph has a new system
coming soon; see his remailer list for details.

Private Idaho is Joel McNamara's friendly user interface for
remailers and PGP.  http://www.eskimo.com/~joelm/pi_list.html .
Runs on MSWindows.  It made it _much_ easier to use the alpha nymserver
while that was still alive; don't know if the new version supports
cyber yet or not.

Remailer security depends on encryption - otherwise wiretappers
can watch mail going into the remailer and know where it's going.
So you'll need to learn to use PGP, but it's pretty straightforward,
and Private Idaho makes it more convenient.

The Mixmaster remailers provide higher security remailing,
also with no reply capability; you need to get special client software,
which I think isn't ported to Windows yet?


>Also, are there any remailers which will accept binary attachments?

There are three popular ways to do binary attachments -
1) MIME-encoding (uses MIME headers and maybe a 7-bit content transfer
encoding.)
2) UUENCODE (simple-minded header and 7-bit ASCII.)
3) Mail-handler-specific headers with binary stuff following

Uuencode is a no-brainer - just stick the uuencoded binary after
the remailer headers.  As far as I know, none of the remailers are
particularly MIME-aware, but they do glue headers together.
So you could probably start sticking MIME headers after the remailer
headers and try a few times to get it to work.

Mail-handler-specific behaviour is, of course, mail-handler-specific :-)
You can try it and see, and remember that the person at the other end
may not have the same kind of mail handler you do, so even if you sent
the mail directly instead of through a remailer, it might not work.
You may have trouble getting your mail client to do what you want
for sending the message (e.g. if you use Cc:Mail or MSMail.)

I looked at the code for my remailer, which is a modified Ghio2,
though I don't think I modified this part, and it'll trash binaries.
The problem is that, after processing headers, it shoves the rest
of the input stream into the output file by a loop of
        fgets()
        check for cutmarks
        fprintf()
which will trash anything that contains nulls, and may not do
the right thing for newlines either, though it won't bother high-bits.
I suppose it wouldn't be too hard to write a getchar/putchar loop
that checks for cutmarks while transferring data safely
(this would be easier if cutmark behaviour includes outputting the cutmark.)
However, the remailer uses the native mail program (e.g. sendmail)
to forward the mail, so if your sendmail trashes binaries,
or does annoying vestigial things like changing "From " to ">From "
at the beginnings of lines, it'll still lose.

#			Thanks;  Bill
# Bill Stewart, +1-415-442-2215 stewarts@ix.netcom.com
# <A HREF="http://idiom.com/~wcs"> 	
# You can get PGP software outside the US at ftp.ox.ac.uk/pub/crypto