Re: [media-types] Multipart without boundaries

[Phillip Hallam-Baker <[e-mail]>]

Content-Length is a HTTP field, it is not a MIME field.

I invented it while fixing a design oversight in the POST method which
didn't work as originally specified as HTTP signalled the end of content by
closing the connection. Which doesn't work for POST since you want to get a
reply.

This came up in a patent lawsuit in which a troll claimed to have invented
Web Mail which was a bit rich given that it was the test case I used to
develop the POST method in 1993 and there was published proof. What they
had done of course was backdate their patent claim by attaching it to a
submarine patent.

MIME doesn't have Content-Length because it is designed to work in SMTP.
HTTP has Content-Length because it is purposefully and deliberately
designed to break if middle boxes molest the content.

I was fully aware of the then current IETF theories in this regard, I just
didn't consider the arguments compelling having repeatedly corrupted FTP
downloads because the braindead spec says to do ASCII conversion by default
and as for having mail servers wrap lines at 72 characters...


On Sat, Mar 16, 2024 at 8:08 PM Harald Alvestrand <[e-mail]>
wrote:

> Thanks for your submission!
>
> The definition of new media types is outside of the charter of MEDIAMAN,
> though.
>
> Personally, I think that using "content-length:" for generic multipart
> content is likely to be a design mistake - there's too much processing
> that subtly alters the length of the message. It would only be
> dependable if you were to pair it with a message checksumming mechanism
> such as Content-MD5 so that content modifications could be detected -
> and it would still not allow you to reconstruct the original message if
> the signature was broken by a transform.
>
> Content delimiting is a subject with long traditions - the "chunked"
> content-transfer-encoding and the delimiting of message bodies in
> HTTP/1.1 are just two of the areas in which it has been approached.
>
>
> On 3/15/24 10:18, Rahul Gupta wrote:
> > Hello Media-type enthusiasts,
> >
> > I am proposing a new Internet-Draft "Multipart without Boundaries".
> >
> https://cxres.github.io/multipart-without-boundaries/draft-gupta-mediaman-multipart-without-boundaries.html
> >
> > Like the title says, it proposes a new syntax that uses `Content-Length`
> in each part and thus does not use boundary delimiter to separate
> encapsulated parts. As explained in the draft, this solves an outstanding
> issue when parts are dynamically generated (and generally simplifies
> parsing), especially when used in notification protocols (It is inspired
> from Braid's subscription response, but respects existing HTTP content-type
> conventions).
> >
> > One issue that I faced while writing this draft is that I could not find
> a IANA registration for the "boundary" parameter for "multipart" media-type
> in any of the registries. So I am not sure of what instructions to give to
> IANA for the "no-boundary" parameter.
> >
> > This is a tiny draft that solves a very specific and limited issue. I
> know that I am too late for I-D submission and publishing it almost on the
> eve of the Brisbane round, but I would still appreciate it if the Chair
> could please sneak it in at least as an announcement (or 5 minute
> discussion) in the Mediaman session.
> >
> > Thanks in advance,
> >
> > Best Regards,
> > Rahul
> >
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