Mixmin and cleanfeed

Adam H. Kerman

unread,

Mar 12, 2013, 12:48:55 PM3/12/13

to

Comments: This message did not originate from the Sender address above.
+ It was remailed automatically by anonymizing remailer software.
+ Please report problems or inappropriate use to the
+ remailer administrator at <ab...@frell.theremailer.net>.
+ Identifying the real sender is technically impossible.
Cc: mail...@m2n.mixmin.net
Message-ID: <9c0ff0efe6c98fb4...@msgid.frell.theremailer.net>
Precedence: anon
Injection-Info: mail2news.mixmin.net; mail-complaints-to=ab...@mixmin.net

Above are selected headers from an article posted via the mail2news
gateway.

Was the Cc added by the author or the gateway? If a Usenet user posted
a followup, wouldn't default settings in a newsreader result in a double
post, once via the user's News server and once via the gateway?

If such a double post would result, isn't that a hugely bad idea? Shouldn't
the gateway reject such a message?

Should Cleanfeed filter such articles?

Russ Allbery

unread,

Mar 12, 2013, 1:32:34 PM3/12/13

to

"Adam H. Kerman" <a...@chinet.com> writes:

> Was the Cc added by the author or the gateway? If a Usenet user posted a
> followup, wouldn't default settings in a newsreader result in a double
> post, once via the user's News server and once via the gateway?

I'd hope not -- I don't see any reason why a news client would, by
default, do anything at all with a Cc header.

--
Russ Allbery (r...@stanford.edu) <http://www.eyrie.org/~eagle/>

Please post questions rather than mailing me directly.
<http://www.eyrie.org/~eagle/faqs/questions.html> explains why.

Steve Crook

unread,

Mar 12, 2013, 1:48:57 PM3/12/13

to

On Tue, 12 Mar 2013 16:48:55 +0000 (UTC), Adam H. Kerman wrote in
Message-Id: <khnm9n$6nb$3...@news.albasani.net>:

> Comments: This message did not originate from the Sender address above.
> + It was remailed automatically by anonymizing remailer software.
> + Please report problems or inappropriate use to the
> + remailer administrator at <ab...@frell.theremailer.net>.
> + Identifying the real sender is technically impossible.
> Cc: mail...@m2n.mixmin.net
> Message-ID: <9c0ff0efe6c98fb4...@msgid.frell.theremailer.net>
> Precedence: anon
> Injection-Info: mail2news.mixmin.net; mail-complaints-to=ab...@mixmin.net
>
> Above are selected headers from an article posted via the mail2news
> gateway.
>
> Was the Cc added by the author or the gateway? If a Usenet user posted
> a followup, wouldn't default settings in a newsreader result in a double
> post, once via the user's News server and once via the gateway?

It's been added by the author. The original was sent to
mail...@dizum.com and Cc'd to mail...@mixmin.net. The To header is
stripped off by the gateway during Post preparation but the Cc slips
through. I've changed this now to also strip the Cc.

> If such a double post would result, isn't that a hugely bad idea? Shouldn't
> the gateway reject such a message?

I don't think a double would happen as the Message-ID should be
identical on both injection methods. Better to strip the Cc though just
to make sure and avoid any ambiguity.

> Should Cleanfeed filter such articles?

No, I don't think so. If the gateway does its job properly and strips
the Cc, the post should be properly formatted.

--
What shall we use
To fill the empty spaces
Where we used to talk?

Adam H. Kerman

unread,

Mar 12, 2013, 2:54:05 PM3/12/13

to

Steve Crook <st...@mixmin.net> wrote:

>On Tue, 12 Mar 2013 16:48:55 +0000 (UTC), Adam H. Kerman wrote:

>>Comments: This message did not originate from the Sender address above.
>>+ It was remailed automatically by anonymizing remailer software.
>>+ Please report problems or inappropriate use to the
>>+ remailer administrator at <ab...@frell.theremailer.net>.
>>+ Identifying the real sender is technically impossible.
>>Cc: mail...@m2n.mixmin.net
>>Message-ID: <9c0ff0efe6c98fb4...@msgid.frell.theremailer.net>
>>Precedence: anon
>>Injection-Info: mail2news.mixmin.net; mail-complaints-to=ab...@mixmin.net

>>Above are selected headers from an article posted via the mail2news
>>gateway.

>>Was the Cc added by the author or the gateway? If a Usenet user posted
>>a followup, wouldn't default settings in a newsreader result in a double
>>post, once via the user's News server and once via the gateway?

>It's been added by the author. The original was sent to
>mail...@dizum.com and Cc'd to mail...@mixmin.net. The To header is
>stripped off by the gateway during Post preparation but the Cc slips
>through. I've changed this now to also strip the Cc.

Thanks.

Adam H. Kerman

unread,

Mar 12, 2013, 2:57:08 PM3/12/13

to

Russ Allbery <r...@stanford.edu> wrote:
>"Adam H. Kerman" <a...@chinet.com> writes:

>>Was the Cc added by the author or the gateway? If a Usenet user posted a
>>followup, wouldn't default settings in a newsreader result in a double
>>post, once via the user's News server and once via the gateway?

>I'd hope not -- I don't see any reason why a news client would, by
>default, do anything at all with a Cc header.

Sorry, I was thinking of another header. Yes, of course it wouldn't.

Adam H. Kerman

unread,

Mar 12, 2013, 3:02:27 PM3/12/13

to

Along the same lines, should a mail2news gateway aimed at the general public
(as opposed to a gateway set up for a specific purpose) reject messages in
which the gateway could be subscribed to a mailing list, in which the gateway
wouldn't appear on To?

If additional addresses appear on To, or any address on Cc, would you
reject the message?

Do you reject a message if another gateway for the general public appears
on To or CC?

These aren't Cleanfeed questions; Subject altered. I suppose my initial
question wasn't a Cleanfeed question either.

Julien ÉLIE

unread,

Mar 13, 2013, 2:51:33 PM3/13/13

to

Hi Adam,

> Along the same lines, should a mail2news gateway aimed at the general public
> (as opposed to a gateway set up for a specific purpose) reject messages in
> which the gateway could be subscribed to a mailing list, in which the gateway
> wouldn't appear on To?
>
> If additional addresses appear on To, or any address on Cc, would you
> reject the message?

I do not see why rejecting the message would be better.

> Do you reject a message if another gateway for the general public appears
> on To or CC?

How can I know the complete list at a given time of other gateways?
I believe accepting a message is OK as long as message-IDs are kept
unmodified.

However, please note this interesting case mentioned in RFC 5537 :

Exceptionally, if there are multiple incoming gateways for a
particular set of messages, each to a different newsgroup(s), each
one SHOULD generate a message identifier unique to that gateway.
Each incoming gateway nonetheless MUST ensure that it does not gate
the same message twice.

NOTE: Consider the example of two gateways of a given mailing list
into two separate Usenet newsgroups, both of which preserve the
email message identifier. Each newsgroup may then receive a
portion of the messages (different sites seeing different
portions). In these cases, where there is no one "official"
gateway, some other method of generating message identifiers has
to be used to avoid collisions. It would obviously be preferable
for there to be only one gateway that crossposts, but this may not
be possible to coordinate.

--
Julien ï¿½LIE

ï¿½ On me tape dessus ï¿½ tout bout de chantï¿½ ï¿½ (Astï¿½rix)

Message has been deleted

Adam H. Kerman

unread,

Mar 16, 2013, 1:00:42 AM3/16/13

to

Julien <iul...@nom-de-mon-site.com.invalid> wrote:
>Hi Adam,

>>Along the same lines, should a mail2news gateway aimed at the general public
>>(as opposed to a gateway set up for a specific purpose) reject messages in
>>which the gateway could be subscribed to a mailing list, in which the gateway
>>wouldn't appear on To?

>>If additional addresses appear on To, or any address on Cc, would you
>>reject the message?

>I do not see why rejecting the message would be better.

You don't see harm in subscribing such a gateway to a mailing list?

>>Do you reject a message if another gateway for the general public appears
>>on To or CC?

>How can I know the complete list at a given time of other gateways?

What if you know that one of the addresses is for another gateway?

>I believe accepting a message is OK as long as message-IDs are kept
>unmodified.

Doesn't a gateway always supply the Message-ID and not use the Message-ID
provided by the user? As the user's host might be identifiable in the
Message-ID, I don't see how its use is compatible with anonymity.

>However, please note this interesting case mentioned in RFC 5537 :

> Exceptionally, if there are multiple incoming gateways for a
> particular set of messages, each to a different newsgroup(s), each
> one SHOULD generate a message identifier unique to that gateway.
> Each incoming gateway nonetheless MUST ensure that it does not gate
> the same message twice.

> NOTE: Consider the example of two gateways of a given mailing list
> into two separate Usenet newsgroups, both of which preserve the
> email message identifier. Each newsgroup may then receive a
> portion of the messages (different sites seeing different
> portions). In these cases, where there is no one "official"
> gateway, some other method of generating message identifiers has
> to be used to avoid collisions. It would obviously be preferable
> for there to be only one gateway that crossposts, but this may not
> be possible to coordinate.

Thanks.

Steve Crook

unread,

Mar 16, 2013, 10:32:03 AM3/16/13

to

On Sat, 16 Mar 2013 05:00:42 +0000 (UTC), Adam H. Kerman wrote in
Message-Id: <ki0u9q$fp7$1...@news.albasani.net>:

>>I do not see why rejecting the message would be better.
>
> You don't see harm in subscribing such a gateway to a mailing list?

Not unless outbound messages from the mailing list include a Newsgroup
header. The gateway will drop any messages that don't include this
header.

>>I believe accepting a message is OK as long as message-IDs are kept
>>unmodified.
> Doesn't a gateway always supply the Message-ID and not use the Message-ID
> provided by the user? As the user's host might be identifiable in the
> Message-ID, I don't see how its use is compatible with anonymity.

The gateway always uses the Message-ID provided by the user. There
is no attempt to anonymize the source in any way.

Adam H. Kerman

unread,

Mar 16, 2013, 3:28:52 PM3/16/13

to

Steve Crook <st...@mixmin.net> wrote:

>On Sat, 16 Mar 2013 05:00:42 +0000 (UTC), Adam H. Kerman wrote:

>>>I do not see why rejecting the message would be better.

>>You don't see harm in subscribing such a gateway to a mailing list?

>Not unless outbound messages from the mailing list include a Newsgroup
>header. The gateway will drop any messages that don't include this
>header.

Hm. That addresses the issue.

>>>I believe accepting a message is OK as long as message-IDs are kept
>>>unmodified.

>>Doesn't a gateway always supply the Message-ID and not use the Message-ID
>>provided by the user? As the user's host might be identifiable in the
>>Message-ID, I don't see how its use is compatible with anonymity.

>The gateway always uses the Message-ID provided by the user. There
>is no attempt to anonymize the source in any way.

Well, some of them do, surely, like dizum. If you retain the Message-ID,
then this gets us back to my earlier question about whether one proto-article
posted to multiple known gateways shouldn't be rejected.

Steve Crook

unread,

Mar 16, 2013, 3:41:55 PM3/16/13

to

On Sat, 16 Mar 2013 19:28:52 +0000 (UTC), Adam H. Kerman wrote in
Message-Id: <ki2h5k$nu4$4...@news.albasani.net>:

>>The gateway always uses the Message-ID provided by the user. There
>>is no attempt to anonymize the source in any way.
>
> Well, some of them do, surely, like dizum. If you retain the Message-ID,
> then this gets us back to my earlier question about whether one proto-article
> posted to multiple known gateways shouldn't be rejected.

I think you may be confusing mail2news gateways with anonymous
remailers. Remailers usually only handle email and rely on gateways for
Usenet posting. They are however, distinctly separate roles.

When people post to Usenet through remailers, the final remailer in a
circuit generates a Message-ID. It then emails the message to one or
more mail2news gateways. The gateways all attempt to post the message
to Usenet using the supplied Message-ID. As the message propagates,
Usenet servers may be offered it from multiple sources, with only the
first being accepted due to the common Message-ID.

Adam H. Kerman

unread,

Mar 18, 2013, 2:42:15 AM3/18/13

to

Steve Crook <st...@mixmin.net> wrote:

>On Sat, 16 Mar 2013 19:28:52 +0000 (UTC), Adam H. Kerman wrote:

>>>The gateway always uses the Message-ID provided by the user. There
>>>is no attempt to anonymize the source in any way.

>>Well, some of them do, surely, like dizum. If you retain the Message-ID,
>>then this gets us back to my earlier question about whether one proto-article
>>posted to multiple known gateways shouldn't be rejected.

>I think you may be confusing mail2news gateways with anonymous
>remailers.

dizum offers both.

>Remailers usually only handle email and rely on gateways for Usenet
>posting. They are however, distinctly separate roles.

>When people post to Usenet through remailers, the final remailer in a
>circuit generates a Message-ID. It then emails the message to one or
>more mail2news gateways. The gateways all attempt to post the message
>to Usenet using the supplied Message-ID. As the message propagates,
>Usenet servers may be offered it from multiple sources, with only the
>first being accepted due to the common Message-ID.

Yes, I see your point.