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Re: Mail Server Registries and Foreign Sender Authentication: A Proposal

2007-03-25 14:20:04

Randy Smith wrote:

Greetings,

I was recently discussing various issues surrounding email with a
coworker and had a couple of ideas for authentication systems that I
would like to get some feedback on. You can read my ideas at
http://perlstalker.blogspot.com/2007/03/mail-server-registries-and-foreign.html.

As I said, I'm looking for feedback. Are these ideas worth pursuing or
am I barking up the wrong tree?

Thank you for your time.


In my opinion, you are not barking up the wrong tree, but the "inevitable tree." Its not a new concept, but a concept we have moved away from in the name of having an open anonymous system. But we seem to be reinventing ourselves to go back to this direction.

In short, you are simply talking about a client/server negotiation handshake stage. In my opinion, maybe not in our "engineering" life time, this is will be the ultimate method of client/server operations. The anonymous sender will be "thing" of the past.

Look at the old Fidonet technology, 100% based on a similar client/server negotiation concepts.

1) Every server MUST be "registered" with a "HOST", in Fidonet, that would be your uplink Net or Zone Host. In the internet, that might be your "ISP", the early forms of Fidonet Net/Zone Hosting systems that were the backbone of the topology.

2) When installing the software, you applied for a FIDONET address and your "ISP" would check your system for 100% FTN compliance before you were assigned a Fidonet Address.

3) You were not allowed to be part of the "net" if you did not have a 100% FTN compliant client and server. Not compliant? No Fidonet address was given to you.

4) There were four basic requirements:

4.a) The software support the legacy FTN1 file transfer protocol. The more advanced IEMSI is akin to what we have today with EHLO and extended server attributes.

4.b) Although you can apply for a private address, ALL servers must be available during Zone Mail Hour (ZMH). This is akin to having a 100% closed system but there were designated times where you allowed anonymous mail (from a registered FTN member) to come in.

4.c) ZMH was designed for making sure ROUTED mail is ALWAYS available. So even if you didn't allow DIRECT mail, a person can send routed mail to you via your HOST which you must ALWAYS accept.

4.d) During ZHM, at a minimum FTN1 must be supported.

There were probably others, but the above were the main things and in addition, the most contentious issues during the "Fidonet/Internet Migration Days."

The legacy FTN1 protocol was REALLY old and it has major problems in packet switching networks. ZMODEM and other file transfer protocols designed for Packet switching networks were part of the newer generation Fidonet software, but were OPTIONAL and not required. However, new developers were not bothering with the older problematic FTN1 protocol and using the new protocols which at least 99% of all systems supported. But the old school FTN net police insisted on FTN1 and rejected applications, registrations of any person installing newer and better software if it didn't have FTN1 support. This turned off alot of developers and with the Internet humming around the corner, and new FTSC (akin to IETF) groups created to get around these policing issues, Fidonet began on a death spiral. The one thing the FTSC had control of was the NodeList, this would be akin to DNS. So new Nodelist ZONE files were created to establish new networks where the FTSC had no control.

In any case, conceptually, we are talking about the same type of direction.

  - Registration of servers and clients within some "controlled
    and centralized" nodelist/DNS system.

  - It will confronted with the same Legacy issues of supporting
    legitimate clients that might not part of the "controlled network."

    As with Fidonet, this is where you will have the major
    uphill battle. The IETF is dead set against breaking the
    the current open network integrity of the system.  Legacy
    software must be supported.

I happen to agree. Legacy software must be supported, however, I am also open to introducing a ZMH like idea where systems are allowed to designate "open" and "closed" times for legacy systems.

Based on these experiences, I had started a IETF draft awhile back that basically defined "SERVER ATTRIBUTES" records that clients will use to obtain server attributes that will cover these client/server negotiation parameters. I happen to believe the idea will be eventually be a major part of the system, in some form or another and we are beginning to touch based with it with DKIM and its SSP ideas. Also look at the growth of SIP communications. It is all going (back) in this direction.

--
Hector Santos/CTO
Santronics Software, Inc.