cc. POWDER public list.
Hi all,
I'm glad Art responded to this so quickly as the original mail was
caught in my spam filter from which I've just retrieved it.
Mea culpa - I was unaware of the Enabling Read Access work. I will make
sure that the POWDER WG considers it fully and that we report back (we
have a face to face meeting on Monday so we can do this quickly).
Meanwhile, we have moved on significantly since the April blog entry
referred to. Yes, we do support Perl regular expressions but we don't
rely on them. Actually, we warn against their use for most scenarios,
precisely because of the same reasons Art cites, preferring instead to
use simple string matches against URI components. Unless something goes
horribly wrong, the member only document at [1] will be a first public
working draft on Monday and this is all set out there.
It would be easy to include a wild card pattern - indeed, there's an
example of exactly that in the extension mechanism section (which refers
to Google's URL pattern format which also looks similar to the one in
the WAF document).
Clearly, there should be a common approach, or at least a fully
compatible one. I notice that Opera is in both groups. Chaals, Anne - I
hereby nominate you as coordinators!
Phil.
[1] http://www.w3.org/2007/powder/Group/powder-grouping/20070709.html
Arthur Barstow wrote:
[[ ++ public-appformats - the mail list the WAF WG uses for its
technical discussions ]]
Stuart - thanks for raising this issue. I have not discussed this issue
with the WAF WG nor the WAF Public Community but here is *my* take on
the syntax issue.
We discussed using regular expression syntax instead of just star. I
recognize there would be some advantages to using the richer syntax but
we decided to follow the KISS principle here, particularly given the
negative side effects of incorrect syntax (e.g. accidentally giving
access to a domain that should not have access). [I assume here the
probability of incorrect syntax is higher with regular expressions than
just star but I have no real data to back my assumption.]
It also appears our decision is consistent with the decision made in the
P3P spec [1].
WAF WG & Community - please see the issue the TAG raises below.
Regards,
Art Barstow
---
[1] <http://www.w3.org/TR/P3P/#ref_file_wildcards>
On Jul 6, 2007, at 10:16 AM, ext Williams, Stuart (HP Labs, Bristol) wrote:
Art, Phil,
In response to a request from the WAF-WG [1] to review "Enabling Read
Access to Web Resources" [2] the TAG is concerned to ensure that there
is good alignment between your WGs wrt the specification of resource
sets.
We observe that [2] involves the specification of 'allow' and 'deny'
sets of resources (which in this case happen to be the origins of
scripted behaviours executed by user agents). There is some resonance
between [2] and POWDER work on grouping resource sets by address. We
believe that there is or should be some common interest in the
specification of such resource sets between your WGs.
Given that web masters are the likely authors of configuration
information for both script access controls (as in [2]) and for
content-labeling (a POWDER application) and that both involve making
assertions about sets of resources (allow/deny assertions v assertions
about the nature of web content) we believe that there should be at
least some conceptual coherence and ideally some syntactic coherence in
the way that both POWDER and WAF-WG approach the description of sets of
resource that are the subject of such assertions.
For example, consider the scenario in which the author of a resource
identified by http://www.sales.example.com/strategy.html wishes to allow
cross-domain access from any resource identified by an example.com URI.
Per [2], this set is specified with a pair of 'access items' as:
http://*.example.com
https://*.example.com
Whereas using the 'PERL regexp' based approach being considered by
POWDER (option 5 at [3]), the same set is specified as:
^https?://[^:/?#]+\.)*example\.com/
We think having two similar-but-different mechanisms to achieve the same
goal should be avoided if at all possible.
We would be interested to hear from you whether you think there is any
possibility of seeking considerably more alignment between the work of
your two groups, so that where their requirements overlap there is at
least cross-reference, and at best sharing of terminology, operational
semantics and perhaps even syntax.
Best regards
Stuart Williams
for W3C TAG
--
[1] http://lists.w3.org/Archives/Public/www-tag/2007Jun/0114.html
[2] http://www.w3.org/TR/2007/WD-access-control-20070618/
[3]
http://www.w3.org/blog/powder/2007/04/27/meeting_summary_26_27_april_200
7
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