ietf-822
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Re: RFC 2047 and gatewaying

2003-01-06 20:12:37

In <3E172358(_dot_)6020404(_at_)alex(_dot_)blilly(_dot_)com> Bruce Lilly 
<blilly(_at_)erols(_dot_)com> writes:

It is insufficient to say "comply with 2822 / 2047 / 2231); there is
a design defect which prevents that, unless a specific mechanism is
provided to ensure compliance.  As it stands,
1. it is impossible for a gateway to determine the syntax of an
   experimental header which the gateway author is unaware of
2. Without header field syntax information, it is impossible to
   encode non-ASCII "header" content.

Yes, there is certainly a design defect, which accounts for why so many
implementations have chosen to fudge their RFC 2047 handling in so many
ways.

The design defect can be eliminated by:

You cannot eliminate a desgin defect, but you can maybe work around it:

a. forbidding non-ASCII content in all but a well-defined set which
   all gateways are required to recognize, *and* providing a practical
   transition plan so that existing gateways can be upgraded while
   ensuring that the mail protocols are not violated

Which is what Usefor is trying to do. But Usefor cannot prevent future
extensions to itself from adding to the set. So you still need a fudge.

As to those existing gateways, I have answered this elsewhere. You would
do well to study a few actual gateways before asserting what would need to
be done to them.

or
b. simply using the RFC 822 / 2822 / 2047 / 2231 Internet text message
   format, which avoids the encoding problem in gateways and adds no
   new restrictions on gateway transformations (thereby obviating that
   aspect of a transition plan).

Yes, but Usefor has chosen a different route.

or
c. require that unrecognized "headers" with non-ASCII content be elided
   or moved to an encoded attachment.

And of your various suggestions, that is the one which deserves serious
consideration. It was #3 in my list IIRC. The question to address is
whether it will do more, or less, harm than my workaround proposal. It is
not clear.

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
Tel: +44 161 436 6131 Fax: +44 161 436 6133   Web: http://www.cs.man.ac.uk/~chl
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