Apt-get update (debian) :

Err: 9 mirrors.cloud.tencent.com/debian-secu… buster/updates Release Certificate verification failed: The certificate is NOT trusted. The certificate chain uses not yet valid certificate. Could not handshake: Error in the certificate verification. [IP: 111.231.36.190 443] Reading package lists… Done

E: The repository ‘mirrors.cloud.tencent.com/debian-secu… buster/updates Release’ does not have a Release file.

N: Updating from such a repository can’t be done securely, and is therefore disabled by default.

N: See apt-secure(8) manpage for repository creation and user configuration details.

E: Release file for mirrors.cloud.tencent.com/debian/dist… is not valid yet (invalid for another 358d 15h 15min 43s). Updates for this repository will not be applied.

E: Release file for mirrors.cloud.tencent.com/debian/dist… is not valid yet (invalid for another 392d 0h 45min 16s). Updates for this repository will not be applied.

E: Release file for mirrors.cloud.tencent.com/debian/dist… is not valid yet (invalid for another 392d 0h 45min 15s). Updates for this repository will not be applied.

During the period even if the switch source is useless, cut the source of each university, each big enterprise, all reported certificate check error.

Try forcing trusted=yes in /etc/apt/sources.list.

deb [trusted=yes] mirrors.ustc.edu.cn/debian/ buster main contrib non-free

Various ways to update the certificate have been tried, but none has worked.

It turns out to be a machine time setting problem because certificate verification is time sensitive. And my machine time is still stuck in last year.

Search the stackoverflow.com/questions/2… Here’s the answer:

Another cause of this problem might be that your clock might be off. Certificates are time sensitive. To check the current system time:

date -R

You might consider installing NTP to automatically sync the system time with trusted internet timeservers from the global NTP pool. For example, to install on Debian/Ubuntu: apt-get install ntp

apt-get install ntp

It was a day’s delay, sin!