Linux使用密钥登录并禁用密码登录

2023-10-18 Ubuntu Debian

生成密钥

# 生成rsa密钥对
ssh-keygen -t rsa

Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):  # 直接enter
Enter passphrase (empty for no passphrase):               # 直接enter
Enter same passphrase again:                              # 直接enter
Your identification has been saved in /root/.ssh/id_rsa   # 生成的私钥
Your public key has been saved in /root/.ssh/id_rsa.pub   # 生成的公钥

安装公钥

# 进入公钥目录
cd /root/.ssh/
# 将公钥写入 /root/.ssh/authorized_keys文件
cat id_rsa.pub >> authorized_keys

设置.ssh权限，防止无法登录

chmod 600 authorized_keys
chmod 700 ~/.ssh

设置ssh打开密钥登录功能

vim /etc/ssh/sshd_config


# 启用密钥验证
PubkeyAuthentication yes
# 关闭密码登录
PasswordAuthentication no

# 允许root用户通过ssh登录
PermitRootLogin yes

重启ssh服务

sudo systemctl restart sshd

如果可以使用密码登录

cat /etc/ssh/sshd_config.d/50-cloud-init.conf
PasswordAuthentication yes

# 将yes改为no 或者直接删除该文件(50-cloud-init.conf)
PasswordAuthentication no