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Re: [openpgp] time representation in OpenPGP

"brian m. carlson" <sandals@crustytoothpaste.net> Sun, 03 July 2016 16:49 UTC

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Date: Sun, 03 Jul 2016 16:49:42 +0000
From: "brian m. carlson" <sandals@crustytoothpaste.net>
To: IETF OpenPGP <openpgp@ietf.org>
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Subject: Re: [openpgp] time representation in OpenPGP
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On Sun, Jul 03, 2016 at 03:57:31PM +0200, Kristian Fiskerstrand wrote:
> On 07/03/2016 03:48 PM, Salz, Rich wrote:
> > I suggest we use ASN1 generalized time (which has only a couple of
> > bytes overhead) or ISO 8601 profiled to be like the ASN1 format:
> > YYYY-MM-DD-HH:MM:SS.sss with fraction optional.
> > 
> 
> ASN1 sounds complex in this case, some form of ISO8601 variant might be
> helpful.
> 
> Alternatively expanding the size of the value from 32 bits to 64 bits
> might be easier to deal with for backwards compatibility reasons.

I'd strongly recommend simply using a 64-bit (signed?) integer.  It's
compact, avoids time zones (which are a source of bugs), and is the
logical extension.

If we use an ISO-8601 variant, it should actually conform with ISO 8601
(unlike GeneralizedTime), and provide a unique encoding for a given
time.  Determinism and uniqueness help avoid collisions and other types
of attacks that might come down the line later, and makes validation
much easier.
-- 
brian m. carlson / brian with sandals: Houston, Texas, US
+1 832 623 2791 | https://www.crustytoothpaste.net/~bmc | My opinion only
OpenPGP: https://keybase.io/bk2204

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