Re: [DNSOP] [Ext] Re: KSK-Sentinal: Once more down the naming rathole.

Petr Špaček <petr.spacek@nic.cz> Thu, 22 February 2018 11:20 UTC

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To: Joe Abley <jabley@hopcount.ca>
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From: Petr Špaček <petr.spacek@nic.cz>
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Subject: Re: [DNSOP] [Ext] Re: KSK-Sentinal: Once more down the naming rathole.
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On 22.2.2018 11:38, Joe Abley wrote:
> Hi Petr,
> 
>> On Feb 22, 2018, at 04:03, Petr Špaček <petr.spacek@nic.cz> wrote:
>>
>> I would prefer decimal for user-friendliness, and zero padding to make
>> implementation easier and faster.
> 
> A few people now have mentioned that they like zero padding. What is
> it about zero padding or fixed-size labels that makes implementation
> easier than specifying no zero padding?

It is important to note that this 'special label trigger' is not seen
anywhere else in DNS, so this is first piece of code which has to match
DNS labels in the 'hot path'.

I think it is a good and easy optimization to minimize use of
regexes/string matching in the hot path, and simple condidion
if (label_len == X || label_len == Y)
before the heavy-weight pattern matching will reduce frequency of regex
use significantly.

We can live without it, but it is so cheap optimization that I do not
see a reason not do it.

Petr Špaček  @  CZ.NIC

> Since zero padding for key tags is not generally seen anywhere else it
> seems more consistent (and hence perhaps less error-prone) to specify
> no zero padding in labels