linux 通过ssh密钥登录

首先建立密钥对

[root@host ~]$ ssh-keygen <== 建立密钥对
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): <== 按 Enter
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase): <== 输入密钥锁码,或直接按 Enter 留空
Enter same passphrase again: <== 再输入一遍密钥锁码
Your identification has been saved in /root/.ssh/id_rsa. <== 私钥
Your public key has been saved in /root/.ssh/id_rsa.pub. <== 公钥
The key fingerprint is:
0f:d3:e7:1a:1c:bd:5c:03:f1:19:f1:22:df:9b:cc:08 root@host

在服务器上导入公钥

cd .ssh
cat id_rsa.pub > authorized_keys

如此便完成了公钥的安装。为了确保连接成功,请保证以下文件权限正确:

chmod 600 authorized_keys
chmod 700 ~/.ssh

设置 SSH,打开密钥登录功能
编辑 /etc/ssh/sshd_config 文件,在文件最后加入下面的命令:

echo "RSAAuthentication yes" >> /etc/ssh/sshd_config
echo "PubkeyAuthentication yes" >> /etc/ssh/sshd_config

另外,请留意 root 用户能否通过 SSH 登录:

PermitRootLogin yes

当你完成全部设置,并以密钥方式登录成功后,再禁用密码登录:

echo "PasswordAuthentication no" >> /etc/ssh/sshd_config

最后,重启 SSH 服务:

service sshd restart