下文讲演示如何利用ssh key 证书实现ssh登陆：
1.[root@postfix .ssh]# vim /etc/ssh/sshd_config
修改ssh配置文件：
RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile .ssh/authorized_keys
StrictModes no
PermitEmptyPasswords no
PasswordAuthentication no
2. cd /home/tangbo
mkdir .ssh
touch .ssh/authorized_keys
chmod 700 .ssh/
chmod 600 .ssh/authorized_keys
chown -R tangbo:tangbo .ssh
3.service sshd restart
4.生成证书：在客户端生成
ssh-keygen -t rsa
[root@postfix .ssh]# cat authorized_keys
将公钥文件复制到该目录内：ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAyAfDQ6UOGLS2drrrJtFYo1F2gvIN6nryxtoV9kCn+dU0hawpqWeYQX1q4qlYNplpESdMV87pSATAfuGihXh0qTY3YAEQhSJst9UniuBwi6lU9jyym8IzWcWe7cmOhoB4gR9u86QItfXLzmLPtMwzd91xgOq2VfhYIMbqXPMPWrM=
5.私钥用于客户端
