Re: [Iot-directorate] [Last-Call] Iotdir telechat review of draft-ietf-core-dev-urn-09

[Russ Housley <[e-mail]>]

Barry:

>> You are, of course, correct.  RFC 5234 says:
>> 
>>      ABNF strings are case insensitive and the character set for these
>>      strings is US-ASCII.
>> 
>> However, that raises a different issue:
>> 
>>   The DEV URN syntax allows both upper and lower case characters.  The
>>   URN-equivalence of the DEV URNs is defined per [RFC8141] Section 3.1,
>>   i.e,. two URNs are URN-equivalent if their assigned-name portions are
>>   octet-by-octet equal after applying case normalization to the URI
>>   scheme ("urn") and namespace identifier ("dev").
>> 
>> So, the ABNF should be changed so that the "mac:", "ow:", "org:", "os:", and "ops:" are required to
>> be lowercase.  I guess that means replacing each letter with the appropriate value in the %x61-7A
>> range.  That will not be as easy to read...
> 
> Not if it's done that way, indeed.  But RFC 7405 helps us here.

Indeed, I forgot about RFC 7405.  Much better solution.

Russ