Re: [dmarc-ietf] Fwd: [Technical Errata Reported] RFC7489 (7865)

[Alessandro Vesely <[e-mail]>]

On Tue 26/Mar/2024 21:57:46 +0100 Matthäus Wander wrote:
> Alessandro Vesely wrote on 2024-03-26 19:30:
>> No.  To take several years and come up with a syntax which does not cover all 
>> valid addresses is a sign of incompetence that this WG doesn't deserve, IMHO. 
>> What do others think?
>>
>> Let's rather switch to /[0-9a-fA-F.:]+/.  Terse and correct.
> 
> I'm in favor of a brief and coarse regex, which is suitable for detecting 
> obvious junk. The above proposal looks good enough to me. I wouldn't mind 
> adding an outer bounds check, e.g.: [0-9a-fA-F.:]{3,45}


I changed that to /[0-9a-fA-F.:]{2,45}/, to allow "::", and inserted it in dmarc-xml-0.2-short.xsd[*].  At the same time, I added a pattern for "::1.2.3.4" in dmarc-xml-0.2.xsd[†].  I tested both against the list of IP that I attach.  (xmllint allows breaking a pattern by backslash+newline, svalidate and xmlstarlet don't.  However, publishing on IETF XML Registry shouldn't have line length limitations.)


> If an implementer sees merit in a comprehensive syntax check, they can add one 
> to their software.


I'm not clear what will that schema be used for, if at all.  Personally, the only reason why I'd prefer the long regex is because it might have some value by itself.  The short one is cleaner and more grokkable.  The wrong one has none of those qualities.


Best
Ale

-- 
[*] https://github.com/alevesely/draft-ietf-dmarc-aggregate-reporting/blob/main/dmarc-xml-0.2-short.xsd
[†] https://github.com/alevesely/draft-ietf-dmarc-aggregate-reporting/blob/main/dmarc-xml-0.2.xsd