DataMuseum.dk

top - metrics - download

    Length: 5391 (0x150f)
    Types: TextFile
    Names: »mail-forgery-help«

└─⟦4f9d7c866⟧ Bits:30007245 EUUGD6: Sikkerheds distributionen
    └─⟦this⟧ »./misc/mail-forgery-help« 

TextFile

From mojo!mimsy!haven!uflorida!rex!samsung!usc!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!aplcen!wb3ffv!ka3ovk!raysnec!shwake Tue Jun  5 19:50:48 EDT 1990
Article: 23377 of comp.unix.questions:
Path: mojo!mimsy!haven!uflorida!rex!samsung!usc!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!aplcen!wb3ffv!ka3ovk!raysnec!shwake
>From: shwake@raysnec.UUCP (Ray Shwake)
Newsgroups: comp.unix.questions
Subject: Re: Unix mail files.
Summary: A contrary opinion
Message-ID: <38@raysnec.UUCP>
Date: 29 May 90 15:44:42 GMT
References: <23447@adm.BRL.MIL> <1163:May2719:09:5690@stealth.acf.nyu.edu>
Reply-To: shwake@raysnec.UUCP (Ray Shwake)
Distribution: na
Organization: IRS - ACI Project Office
Lines: 22

In article <1163:May2719:09:5690@stealth.acf.nyu.edu> brnstnd@stealth.acf.nyu.edu (Dan Bernstein) writes:

>Yep, exactly right. You'll also note that if a line in the text of a
>message starts with From and a space, the mailer adds a > to the line;
>that way mailreaders won't think that it starts a new message.
>To be precise, the separator is "\n\nFrom ".

The > prefix on lines beginning with From is also intended to cut down on
mail forgeries. Also, while "\n\nFrom " is present BETWEEN messages, the
mailer will often simply look at each line and, if it begins with "From "
judge it to be the start of the next message. You can confirm this by
eliminating the blank line between messages and see if your mailer still
separates your messages.

>There are other popular conventions for mail. The easiest to work with
>has every message in a separate file; unfortunately, this also wastes
>the most space.

This is an arguable position. Separating messages certainly does waste
more space, but makes for a more complex directory structure by requiring
(for efficiency sake) a separate directory for each subject collection,
and makes movement between messages horribly inefficient.


From mojo!mimsy!haven!aplcen!samsung!zaphod.mps.ohio-state.edu!rpi!crdgw1!underdog!volpe Tue Jun  5 20:04:22 EDT 1990
Article: 23474 of comp.unix.questions:
Path: mojo!mimsy!haven!aplcen!samsung!zaphod.mps.ohio-state.edu!rpi!crdgw1!underdog!volpe
>From: volpe@underdog.crd.ge.com (Christopher R Volpe)
Newsgroups: comp.unix.questions
Subject: Re: Unix mail files.
Message-ID: <8129@crdgw1.crd.ge.com>
Date: 1 Jun 90 17:50:18 GMT
References: <23447@adm.BRL.MIL> <1163:May2719:09:5690@stealth.acf.nyu.edu>
Sender: news@crdgw1.crd.ge.com
Organization: General Electric Corporate R&D Center
Lines: 20

In article <1163:May2719:09:5690@stealth.acf.nyu.edu> brnstnd@stealth.acf.nyu.edu (Dan Bernstein) writes:
>
>Yep, exactly right. You'll also note that if a line in the text of a
>message starts with From and a space, the mailer adds a > to the line;
>that way mailreaders won't think that it starts a new message.
>
>To be precise, the separator is "\n\nFrom ".

The SunOS mail program that I use doesn't seem to use that as
a separator. I sent a message to myself containing "From me@here" in
the body of the message after two carriage returns, and indeed the ">"
was automatically inserted, but I directly edited my spool file 
and removed the ">". When I invoked "mail" to read it, It didn't
confuse the line in the text with the start of a new message,
even though the ">" was no longer there. Could there be some
control characters inserted somewhere?

Chris Volpe
G.E. Corporate Research and Development
VOLPECR@CRD.GE.COM


From mojo!mimsy!cvl!haven!adm!news Tue Jun  5 20:18:20 EDT 1990
Article: 23513 of comp.unix.questions:
Path: mojo!mimsy!cvl!haven!adm!news
>From: rbottin@atl.calstate.edu (Richard John Botting)
Newsgroups: comp.unix.questions
Subject: Re: Unix mail files
Message-ID: <23510@adm.BRL.MIL>
Date: 3 Jun 90 05:23:19 GMT
Sender: news@adm.BRL.MIL
Lines: 46

In article <1163:May2719:09:5690@stealth.acf.nyu.edu> brnstnd@stealth.acf.nyu.ed
u (Dan Bernstein) writes:
>
>Yep, exactly right. You'll also note that if a line in the text of a
>message starts with From and a space, the mailer adds a > to the line;
>that way mailreaders won't think that it starts a new message.
>
>To be precise, the separator is "\n\nFrom ".
Christopher R Volpe <volpe@underdog.crd.ge.com> adds
>The SunOS mail program that I use doesn't seem to use that as
>a separator. [...]
>Could there be some control characters inserted somewhere?

I would place small bet on 4 CTRL/A's
because this is what about 50% of our mail system does at silicon.???.csusb.edu.
The other half  doesn't put in these characters
(Please don't ask me why - I assume insanity on the part of the programmers)
(whio would doubtless prefer to reamin anonymous)

The fun starts when a third process parses mail...this appears to use the
FIRST line to determine what the seperator between the messages is.

In consequence we often find 6 or 7 or messages all masquerading as a
single one...

I wrote a script to clean my mail out, then some others tried it as well.
As of tonight it went into service from root - as a crontab...It reads:
: clean dumb sentinels from mail files
cd /usr/spool/mail
for mbox in *
do echo $mbox
ed - $mbox <<++++ 2>/dev/null
g//s///
w
q
++++
done

By the way - g//s/// is not what it appears to be you'll have to insert
4 CTRL/A's    ^here
:-)
Dr. Richard J Botting (The Aging Hacker)
Computer Science Dept
CalStateUniversity, San Bernardino.
rbottin@atl.calstate.edu
paaaaar@calstate.bitnet