DnA 9-10: Anonymous Internet Remailer Info

Published in

· 1 year ago

NOTE! I make no claim of writing this..This is the help file for anon.penet.fi to get an anonymous remailer E-mail anon@anon.penet.fi and they will set you up with an acct.

vandal@netcom.com

The anon.penet.fi Anonymous Server

Yes, another anonymous server. Why? Well, several well-known servers have bitten the dust recently. And most of them have served only a very limited subset of newsgroups, and mail only to "registered", anonymous users.

Due to reasons too complicated to mention here I wanted to set up an anonymous server for the scandinavian user community. I got hold of a pre-release copy of one of the server packages. As the version I got relied heavily on the advanced features of MMDFII, I had to modify it quite a bit. While hacking around, I removed the restriction of only supporting selected newsgroups. Within a week of startup, the server had been discovered by transatlantic users, and more recent stats show european users are definitely a minority.

So what does the anon server really do? Well, it provides a front for sending mail messages and posting news items anonymously. As you send your very first message to the server, it automatically allocates you an id of the form anNNN, and sends you a message containing the allocated id. This id is used in all your subsequent anon posts/mails. Any mail messages sent to your-id@anon.penet.fi gets redirected to your original, real address. Any reply is of course anonymized in the same way, so the server provides a double-blind. You will not know the true identity of any user, unless she chooses to reveal her identity explicitly.

In the anonymization process all headers indicating the true originator are removed, and an attempt is made to remove any automatically-included signatures, by looking for a line starting with two dashes (--), and zapping everything from there on. But if your signature starts with anything else, it's your own responsibility to remove it from your messages.

There are two basic ways to use the system. The easiest way is by sending a message to recipient@anon.penet.fi:

	To: alt.sex.bestiality@anon.penet.fi 

	To: an9999@anon.penet.fi 

	To: help@anon.penet.fi

Of course, in the case of mailing to a known user, you have to use addresses of the form user%host.domain@anon.penet.fi, or the pretty obscure source addressing construct of @anon.penet.fi:user@host.domain. These constructs are not necessarily handled properly by all mail systems, so I strongly recommend the "X-Anon-To:" approach in these cases. This works by you sending a message to "anon@anon.penet.fi", including a X-Anon-To: header line containing the desired recipient. But this really has to be a field in the message header, before the first empty line in the message. So:

	To: anon@anon.penet.fi 
	X-Anon-To: alt.sex.needlework,rec.masturbation 

	To: anon@anon.penet.fi 
	X-Anon-To: jack@host.bar.edu

Valid recipients in both cases are fully qualified user addresses in RFC-822 format (user@host.domain), anon user id's (anNNN), newsgroup names (alt.sex.paperclips) or one of the "special" user names of ping, nick, help, admin and stat.

Sending to "ping" causes a short reply to be sent confirming (and allocating, if needed) your anon id. "nick" takes the contents of the Subject: header and installs it as your nickname. If you have a nickname, it appears in the From: header in the anonymized message along with your anon id. "help" returns this text, and stat gives some statistics about the system. Mail to "admin" goes directly to me unanonymized, and can be used to report problems. If you want to send mail to me anonymously, you can use "an0".

When crossposting to several newsgroups, you can list several newsgroups separated by commas as recipients, but this only works using the X-Anon-To: header. References: headers do work, so they can (and should) be used to maintain reply threads.

Ah yes, please remember that the posting takes place at my local site, so you can only post to groups that are received at penet.fi. I get all "worldwide" groups, but various exotic local groups don't make it here. I have gotten a couple of comments about permitting anonymous postings to technical groups. I can only answer that I believe very firmly that it's not for me to dictate how other people ought to behave. Somebody might have a valid reason for posting anonymously to a group I might consider "technical". But remember anonymous postings are a privilege, and use them accordingly. I believe adult human beings can behave responsibly. Please don't let me down.

As the server was originally intended to be used by scandinavians, it includes help files for various languages. This works by using the language in question as the address. So to get the german help file, send a message to german@anon.penet.fi (or deutsch@anon.penet.fi). Support for new languages is added every now and then, when I find volunteers to do the translation. Any new ones?

The user-id database is based on RFC822-ized forms of your originating address. This may cause problems for some users, either because their site is not properly registered in the name servers, resulting in non-deterministic addresses, or because their mail router doesn't hide the identity of individual workstations, resulting in different originating addresses depending on which workstation you mail from. Talk to your administrator. If that doesn't help, let me know, and I will make a manual re-mapping.

You might wonder about the sense of using a server out somewhere, as the song goes, "so close to Russia, so far from Japan". Well, the polar bears don't mind, and the ice on the cables don't bother too much :-) Well, in fact, as we live in a wonderfully networked world, the major delay is not going over the atlantic, but my local connection to the Finnish EUnet backbone, fuug.fi. Once you reach a well-connected host, such as uunet.uu.net, there's a direct SMTP connection to fuug.fi. My connection to fuug.fi is currently a polled connection over ISDN, soon to be upgraded to on-demand-SMTP/NNTP. But for now, expect a turn-around delay of 2-4 hours for trans-atlantic traffic.

Short of having everyone run a public-key cryptosystem such as PGP, there is no way to protect users from malicious administrators. You have to trust my personal integrity. Worse, you have to trust the administrators on every mail routing machine on the way, as the message only becomes anonymous once it reaches my machine. Malicious sysadmins and/or crackers could spy on SMTP mail channels, sendmail queues and mail logs. But as there are more than 3000 messages being anonymized every day, you have to be pretty perverted to scan everything...

Another thing is mail failures. I've had cases of mail routers doing the wrong thing with % addresses, "shortcutting" the path to the destination site. This could cause your mail to go to the final destination without ever touching my server (and thus without getting anonymized). This can be avoided by using the X-Anon-To: method.

And if your return address bounces for some reason (nameservers down, temporary configuration failures etc.), the original sender and/or postmasters on the way might get error messages showing your true identity, and maybe even the full message.

There is at least one known way to discover the anon id of a user. It involves being able to falsify your real identity, so it is not too easy to use, and it doesn't reveal the real address lurking behind an anon id, but it can be used to discover what anon id a certain user is using. To fix this problem, the server requires that you use a password when you try to mail to a non-anonymous user.

First you have to set a password by mailing to password@anon.penet.fi, with a message containing only your password. The password can be any string of upper- or lowercase characters, numbers and spaces.

Once you have set your password, you must include it in all your messages, in a "X-Anon-Password:" line. As with the X-Anon-To: line, it can be either a part of the header or as the first non-empty line of the message text.

So your first message might look like this:

	To: password@anon.penet.fi 

	XYZZY99998blarf

And your subsequent messages might look like something like this:

	To: anon@anon.penet.fi 
	Subject: Test... 
	X-Anon-To: foo@bar.fie 
	X-Anon-Password: XYZZY99998blarf

If you find this is too much of a hassle, and don't care too much about the confidentiality of your anon id, you can set the password to "none", in which case the server doesn't require you to have a password.

If you suddenly discover that the server requires a password for posting stuff etc, somebody has managed to use your account and set a password. In that case, contact admin@anon.penet.fi.

Crackers are just too clever. Undoubtedly somebody is going to come up with some novel method.... Not much I can do about that...

If you intend to mail/post something that might cost you your job or marriage or inheritance, _please_ send a test message first. The software has been pretty well tested, but some mailers on the way (and out of my control) screw things up. And if you happen to find a problem, _please_ for the sake of all the other users, _let me know asap_.

And _please_ use the appropriate test newsgroups, such as alt.test or misc.test. Yes, _you_ might get excited by reading 2000 "This is a test.." messages on alt.sex, but I warn you that most psychologists consider this rather aberrant...

And remember this is a service that some people (in groups such as alt.sexual.abuse.recovery) _need_. Please don't do anything stupid that would force me to close down the service. As I am running my own company, there is very little political pressure anyone can put on me, but if somebody starts using the system for criminal activities, the authorities might be able to order me to shut down the service. I don't particularly want to find out, however...

If you think these instructions are unclear and confusing, you are right. If you come up with suggestions for improving this text, please mail me! Remember English is my third language...

Safe postings!

Julf