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Re: [dmarc-ietf] ABNF errors on RFC7489 and dmarcbis-07

Olivier Hureau <olivier.hureau@univ-grenoble-alpes.fr> Thu, 21 April 2022 17:21 UTC

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Date: Thu, 21 Apr 2022 19:21:22 +0200
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From: Olivier Hureau <olivier.hureau@univ-grenoble-alpes.fr>
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Subject: Re: [dmarc-ietf] ABNF errors on RFC7489 and dmarcbis-07
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Hello,

Todd pointed out that the  with the "v=DMARC1" txt records for external 
verification explain why 'dmarc-request' is optional but we can still 
modified the rules in this way.

I also found out that on the with current rules : tags can be in 
uppercase (the only strings that are "hardcoded" are the "DMARC1" from v 
tag) and it also allow whitespace between the tag, the "=" and the value.

As it the above TXT records are valid :
- "V=DMARC1;P=REJECT"
- "v=DMARC1; p=ReJeCt"
- "v=DMAR1; p     =    reject"

A lot of dmarc libraries out there says that the records is not valid, 
but according to the RFC7489 : it is.
Doing some active measurements on some email service provider i also 
found that some are case/whitespace sensitive.

I am currently writing a paper and want to submit it at the Applied 
Networking Research Workshop - IETF-114. I hope I will share all my 
results with you in a near future.

Regards,

Olivier

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