# 把以下写入 /etc/apt/sources.list.d/ustc.sources
Types: deb
URIs: http://mirrors.ustc.edu.cn/debian
Suites: bookworm bookworm-updates
Components: main contrib non-free non-free-firmware
Signed-By: /usr/share/keyrings/debian-archive-keyring.gpg
Types: deb
URIs: http://mirrors.ustc.edu.cn/debian-security
Suites: bookworm-security
Components: main contrib non-free non-free-firmware
Signed-By: /usr/share/keyrings/debian-archive-keyring.gpg
sudo apt update
sudo apt install apt-transport-https ca-certificates
# 把上段代码框内的所有 http: 改为 https:
sudo apt update