Hi Max -
I think I pushed the wrong button and sent out the wrong email. My
original email had this (limit is 6 digits) comment in it, but I'd
actually decided not to send it because I couldn't find a definitive source.
X.680 used the phrase "a time of day, to any of the precisions defined
in ISO 8601..." (clause 42.2 (b) ) and I'd found another reference that
suggested that 6 digits was the maximum "defined" precision. But I
couldn't find an actual version of 8601 so I wasn't sure if the
reference was reasonably interpreting 8601 so I'd decided not to send.
So what I'm saying is - ignore my email. Sorry.
Mike
On 6/12/2017 9:48 PM, Weijun Wang wrote:
On 06/13/2017 09:44 AM, Weijun Wang wrote:
Hi Michael
I cannot access ISO 8601 but according to
https://en.wikipedia.org/wiki/GeneralizedTime:
A GeneralizedTime is a time format in the ASN.1 notation. It consists
of a string value representing the calendar date, as defined in ISO
8601, a time of day with an optional fractional seconds element and
the optional local time differential factor as defined in ISO 8601.
In contrast to the UTCTime class of ASN.1 the GeneralizedTime uses a
four-digit representation of the year to avoid possible ambiguity.
Another difference is the possibility to encode time information of
any wanted precision via the fractional seconds element.
So my understanding is that ISO 8601 is only for "the optional local
time differential factor", and it does mention "any wanted precision".
Oh, ISO 8601 is for "the calendar date" and "the optional local time
differential factor", but not "a time of day with an optional
fractional seconds element".
--Max
In fact, I tried to generate a DER encoding of a GeneralizedTime with
a long fractional part and "openssl asn1parse" accepts it and
displays all the digits.
I can read X.680 but it does not mention any restriction.
Thanks
Max
On 06/13/2017 01:07 AM, Michael StJohns wrote
The actual bound in GeneralizedTime is 6 digits of fractional time
(according to ISO 8601) or 25 characters. That should still continue
to be enforced.
