Hello,

I wanted to understand exactly how the MS Certificate
Authority determines the actual CRL validity period and
how to control it precisely. I am interested in knowing
the variance (how much etc.) it adds to the publish
interval which seems like a grey area to me.

I tried the following. I set these values in the
relevant registry entries on my CA (Windows 2000 Ent CA):

CRLPeriod REG_SZ = Hours
CRLPeriodUnits REG_DWORD = 1

CRLOverlapPeriod REG_SZ = Hours
CRLOverlapUnits REG_DWORD = 1

Note this CA do not do deltas.

After adding the CRLOverlapxx reg values I bounced the
service and forced a CRL publish at 2pm PST but the CRL
validity of this latest CRL shows up as:

Effective Date: Tuesday, July 22, 2003 11:39:21 AM
Next update: Tuesday, July 22, 2003 9:24:21 PM

I want to understand the math used for arriving at this
validity period when I have the above settings.

Related question would: What is the minimum validity
period that one can publish a CRL with on a MSCA? Like for
eg. can I have a CRL that is valid only/exactly for 1 or 2
hrs.

Thanks.
Jayant