Hello Andrej

I think one way is implement RTC as a secure RTC, and configure it by secure entity like BMC.

Is there a reliability issue with this?

Best Regards,

Masato Fukumori

From: Andrej Butok <andrey.butok@nxp.com>
Sent: Thursday, December 10, 2020 10:33 PM
To: Fukumori, Masato/福森 将人 <fukumori.masato@fujitsu.com>
Cc: tf-a <tf-a@lists.trustedfirmware.org>
Subject: RE: Question about validity period of X509 certificate

Hello Masato Fukumori,

To check a "validity period" of a X 509 certificate,

you must be sure that your system date & time is set, correct and not changed.

Do you have a reliable way to achieve this?

Best regards,

Andrej Butok

From: TF-A <tf-a-bounces@lists.trustedfirmware.org> On Behalf Of fukumori.masato--- via TF-A
Sent: Thursday, December 10, 2020 2:23 PM
To: 'tf-a@lists.trustedfirmware.org' <tf-a@lists.trustedfirmware.org>
Subject: [TF-A] Question about validity period of X509 certificate

Hello.

I have a question about checking the X 509 certificate with tf-a.

My understanding is that tf-a does not check the "validity period" of the X 509 certificate.

I 'm not sure why tf-a doesn't check. Does anyone know this background?

Best Regards,

Masato Fukumori