RE: DR 10-0048 ― OPC: Processing model for handling ZIP encryption

[Chris Rae]

Hi Murata-san - I did notice Bit 5 as well while I was looking at this DR, and I agree that we need to look at this more thoroughly once the WG1 work is finished.

Rex, I wonder if we can have yet another DR category, that being "pending WG1 ZIP standard"? We do have a few DRs in a similar bucket.

Chris

-----Original Message-----
From: eb2mmrt at gmail.com [mailto:eb2mmrt at gmail.com] On Behalf Of MURATA Makoto
Sent: 15 February 2011 18:08
To: Chris Rae
Cc: e-SC34-WG4 at ecma-international.org
Subject: Re: DR 10-0048 ¡ª OPC: Processing model for handling ZIP encryption

Chris,

Because this bit is used by PKWARE and also because we should make our intention clear, I would propose "The use of this bit is allowed in ZIP Appnote.txt but is disallowed in this part of ISO/IEC 29500"
rather than "currently unused".

BTW, the same comment applies to at least one bit, namely Bit 5:

  If this bit is set, this indicates that the file is
  compressed patched data. (Requires PKZIP version
  2.70 or greater.)

This DR again demonstrates that we do need the multi-part standard proposed by WG1 and finish this kind of subsetting only once for OOXML, ODF, and EPUB among others.  For now, I do not think that we can do thorough reengineering.

Cheers,
Makoto

2011/2/16 Chris Rae <Chris.Rae at microsoft.com>:
> http://cid-c8ba0861dc5e4adc.office.live.com/view.aspx/Public%20Documen
> ts/2010/DR-10-0048.docx
>
> This DR covers some odd wording around "ignoring" encryption features of ZIP that can't really be ignored. I've had a chat with some people here and I think the statement made in the DR is correct - this bit cannot be ignored. Given that IS 29500 doesn't support encryption within the standard, I think the best solution is to mark this bit as "currently unused" (the wording used in other flags which aren't supported by Part 2) and state that it will not be preserved on round-trip, as a file that's encrypted cannot be round-tripped.
>
> Proposed changes are attached.
>
> Chris
>



--
 --
¹úëH´óѧ
´åÌï¡¡Õæ <EB2M-MRT at asahi-net.or.jp>