apt 源切到国内时出现证书验证不过问题

1，问题

ubuntu 22.04 

apt 源切到国内时，执行 apt-get update 报错：

Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown.  Could not handshake: Error in the certificate verification.

2，解决

先切回原先的 apt 源，

更新证书：

sudo apt update --fix-missing  # 尝试修复
sudo apt install --reinstall ca-certificates
sudo update-ca-certificates --fresh

再切到国内的 apt 源