Re: Syntax validation of articles by injecting agents

["Charles Lindsey" <chl@xxxxxxxxxxxxxxxx>]

In <87aawzdj5e.fsf@xxxxxxxxxxxxxxxxxxxxx> Russ Allbery <rra@xxxxxxxxxxxx> writes:

>Julien ÉLIE <julien@xxxxxxxxxxxxxxx> writes:

>> RFC 5537 mentions that an injecting agent MUST reject any proto-article
>> that is not syntactically valid as defined by RFC 5536.

>In retrospect, I suspect that should either have been a SHOULD or it
>should have singled out the netnews-specific restrictions.  I don't think
>anyone pointed out at the time that it would mean rejecting all non-MIME
>messages, and I suspect we would have changed it if we'd realized that as
>fairly impractical.

Eh? How does it imply that? If there are no Content-* headers, then there
is no requirement for MIME-Version.

>The point was more to reject messages with syntactically invalid
>Newsgroups headers and whatnot.

>> And what if a news reader generates an incorrect User-Agent: header
>> field?  or if it always adds a tail-entry which is not a path-nodot
>> in Path:?  All its posts will be rejected by a RFC-compliant injecting
>> agent...
>> It it the intention?

>I wonder how many user agents generate invalid Path headers.  Hm.

But aren't injecting agents allowed to remove a Path header that is
received? For sure, many of them routinely do. In any case, fixing (or
removing) a broken header is always a way out of the problem.

>I have a hard time justifying rejecting articles on the basis of syntactic
>problems in purely informational headers like User-Agent.

>> I quite understand that it would help to have better compliant
>> articles.  For instance, rejecting articles with "all" in their
>> distribution list.

>That, at least, the user probably has some control over.


>> How can we handle that MUST without hurt?

Well any leniency should only apply to things the user cannot control. But
the world will not suddenly end if some implementation usees Common Sense
in cases that will do no practical harm.

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
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