今天在linux（个人采用debian，其他系统类似）上安装一个包的时候遇到了如下的错误:

重点有这么一行错误：

Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown. Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]

Reading package lists... Done

root@DESKTOP-R5MSHA1:~# apt-get update
Err:1 https://mirrors.aliyun.com/debian bullseye InRelease
  Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown.  Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]
Err:2 https://mirrors.aliyun.com/debian-security bullseye-security InRelease
  Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown.  Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]
Err:3 https://mirrors.aliyun.com/debian bullseye-updates InRelease
  Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown.  Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]
Err:4 https://mirrors.aliyun.com/debian bullseye-backports InRelease
  Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown.  Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]
Reading package lists... Done
W: https://mirrors.aliyun.com/debian/dists/bullseye/InRelease: No system certificates available. Try installing ca-certificates.
W: https://mirrors.aliyun.com/debian-security/dists/bullseye-security/InRelease: No system certificates available. Try installing ca-certificates.
W: https://mirrors.aliyun.com/debian/dists/bullseye-updates/InRelease: No system certificates available. Try installing ca-certificates.
W: https://mirrors.aliyun.com/debian/dists/bullseye-backports/InRelease: No system certificates available. Try installing ca-certificates.
W: Failed to fetch https://mirrors.aliyun.com/debian/dists/bullseye/InRelease  Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown.  Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]
W: Failed to fetch https://mirrors.aliyun.com/debian-security/dists/bullseye-security/InRelease  Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown.  Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]
W: Failed to fetch https://mirrors.aliyun.com/debian/dists/bullseye-updates/InRelease  Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown.  Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]
W: Failed to fetch https://mirrors.aliyun.com/debian/dists/bullseye-backports/InRelease  Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown.  Could not handshake: Error in the certificate verification. [IP: 219.144.101.241 443]
W: Some index files failed to download. They have been ignored, or old ones used instead.

解决方案，CA证书

apt-get install --reinstall ca-certificates

然后重新运行 apt-get update：

root@DESKTOP-R5MSHA1:~# apt-get update
Hit:1 https://mirrors.aliyun.com/debian bullseye InRelease
Get:2 https://mirrors.aliyun.com/debian-security bullseye-security InRelease [48.4 kB]
Hit:3 https://mirrors.aliyun.com/debian bullseye-updates InRelease
Get:4 https://mirrors.aliyun.com/debian bullseye-backports InRelease [49.0 kB]
Get:5 https://mirrors.aliyun.com/debian bullseye/contrib Sources [43.2 kB]
Get:6 https://mirrors.aliyun.com/debian bullseye/non-free Sources [81.2 kB]
Get:7 https://mirrors.aliyun.com/debian bullseye/main Sources [8,633 kB]
Get:8 https://mirrors.aliyun.com/debian bullseye/non-free amd64 Packages [97.7 kB]
Get:9 https://mirrors.aliyun.com/debian bullseye/non-free Translation-en [92.4 kB]
Get:10 https://mirrors.aliyun.com/debian bullseye/contrib amd64 Packages [50.6 kB]
Get:11 https://mirrors.aliyun.com/debian bullseye/contrib Translation-en [46.9 kB]
Get:12 https://mirrors.aliyun.com/debian-security bullseye-security/main Sources [169 kB]
Get:13 https://mirrors.aliyun.com/debian-security bullseye-security/main amd64 Packages [200 kB]
Get:14 https://mirrors.aliyun.com/debian-security bullseye-security/main Translation-en [129 kB]
Get:15 https://mirrors.aliyun.com/debian bullseye-updates/main Sources [4,812 B]
Get:16 https://mirrors.aliyun.com/debian bullseye-backports/main Sources [358 kB]
Get:17 https://mirrors.aliyun.com/debian bullseye-backports/contrib Sources [2,868 B]
Get:18 https://mirrors.aliyun.com/debian bullseye-backports/non-free Sources [4,552 B]
Get:19 https://mirrors.aliyun.com/debian bullseye-backports/main amd64 Packages [361 kB]
Get:20 https://mirrors.aliyun.com/debian bullseye-backports/main Translation-en [297 kB]
Get:21 https://mirrors.aliyun.com/debian bullseye-backports/non-free amd64 Packages [14.3 kB]
Get:22 https://mirrors.aliyun.com/debian bullseye-backports/non-free Translation-en [26.6 kB]
Get:23 https://mirrors.aliyun.com/debian bullseye-backports/contrib amd64 Packages [4,400 B]
Get:24 https://mirrors.aliyun.com/debian bullseye-backports/contrib Translation-en [4,320 B]
Fetched 10.7 MB in 2min 3s (86.9 kB/s)
Reading package lists... Done