Proper identifier for Excel-style digest algorithm

[Kohei Yoshida <kyoshida@novell.com>]

Hi there,

I've already asked privately to Michael and Rob, and I think it's
appropriate to ask this list.

I'm working on supporting the password hash algorithm that Excel uses to
hash worksheet and document passwords in OOo.  Luckily this doesn't
require any modification to the ODF schema since ODF already allows
alternative digest algorithm as described in Section 18.972
table:protected (as of v1.2 draft7-3).  But I'd like to correctly
associate and document this Excel-style algorithm in the ODF spec.

The algorithm itself is documented in Section 3.3.1.81 of ECMA TC-45
OOXML specification.  The code contained therein, however, is not
entirely correct, so I posted the correct algorithm in my blog page[1]
for now.  I assume the final version of the OOXML spec will contain the
correct algorithm, but so far, the latest (public) version of the spec
that I have access to still contains the old, incorrect version.

The question I'd like to ask the list members is this: what identifier
should we use as the value of the table:protection-key-digest-algorithm
attribute to refer to the new algorithm?  The current definition for
this attribute:

<attribute name="table:protection-key-digest-algorithm" 
           a:defaultValue="http://www.w3.org/2000/09/xmldsig#sha1";>
    <ref name="anyURI"/>
</attribute>

suggests that the name must be a URI.  But I'm not sure what URI to use
for this new algorithm.

Any ideas, anyone?

Kohei

[1] http://kohei.us/2008/01/18/excel-sheet-protection-password-hash/

-- 
Kohei Yoshida - OpenOffice.org Engineer - Novell, Inc.
<kyoshida@novell.com>