RE: WG LAST CALL: draft-ietf-smime-rfc2633bis-07.txt

[Russ Housley <[e-mail]>]

My understanding of the MIME registration is that ZLIB is really used.

Russ


At 09:05 PM 3/1/2004 -0500, Hollenbeck, Scott wrote:
> >       If an implementation chooses to support compression, then
> >       the implementation MUST support the ZLIB compression
> >       algorithm.
> >
> > Russ
>
>Something to consider: ZLIB (RFC 1950) and DEFLATE (RFC 1951) are NOT the
>same thing.  I ran into a small bit of specification confusion (thankfully
>caught by Ned Freed) when my TLS compression draft went through IESG review.
>It might be worth noting Ned's comments so that rfc2633bis specifies the
>algorithm you intend:
>
>"First of all, it is important to realize that RFC 1950 and RFC 1951 specify
>two things: (1) A compression scheme and corresponding format called DEFLATE
>(1951) and (2) A general wrapper format for compressed data called ZLIB
>(1950).
>I believe most compression applications simply use the DEFLATE format and
>don't
>bother with the extra wrapper and most of our specifications that do this
>refer to deflate and RFC 1951 rather than zlib and RFC 1950.
>
>This document doesn't follow this approach. Rather, it repeatedly calls
>the compression scheme ZLIB and refers to both of the RFCs. Does this mean
>this specification actually uses the zlib wrapper? I suspect the answer
>is no, and if that's indeed the case, the document needs to be clarified
>in this regard. I suggest referring to the scheme as DEFLATE and removing
>the reference to RFC 1950 entirely.
>
>If, on the other hand, the intent really is to use the zlib wrapper, then
>the specification is incomplete in that ZLIB allows for multiple compression
>algorithms, checksumming, and so forth. These various settings would need to
>be specified in order to have interoperable ZLIB implementations."
>
>-Scott-