之前写《搭建基于SSH的Git服务器》
，有大致讲过SSH远程登陆
现在完整的小结一下
首先是SSH Key的生成

ssh-keygen -t rsa -C "byhook@163.com"  

根据提示输入密码

Generating public/private rsa key pair.  
Enter file in which to save the key (/home/byhook/.ssh/id_rsa):   
Enter passphrase (empty for no passphrase):   
Enter same passphrase again:   
Your identification has been saved in /home/byhook/.ssh/id_rsa.  
Your public key has been saved in /home/byhook/.ssh/id_rsa.pub.  
The key fingerprint is:  
f5:9a:53:d3:97:d1:61:11:81:f6:9a:53:e1:c2:ab:62 byhook@163.com  
The key's randomart image is:  
+--[ RSA 2048]----+  
|              .*+|  
|             o..o|  
|          . o o.o|  
|         . . + +o|  
|        S   + B..|  
|           + * . |  
|          + . .  |  
|         E o     |  
|        . .      |  
+-----------------+  

生成的id_rsa文件是私有密钥
id_rsa.pub是公开的密钥
查看公钥的内容

cat ~/.ssh/id_rsa.pub 

不建议用root用户来开启SSH登陆
建议新创建一个用户

#远程登陆
ssh root@192.168.1.104
#创建新用户
useradd andy
#配置密码
passwd andy

本机现在可以上传公钥到服务器

#本机复制公钥到服务器
scp -r ~/.ssh/id_rsa.pub andy@192.168.1.104:~/
#远程登陆
ssh andy@192.168.1.104

用户andy配置授权

cd ~
mkdir .ssh 
cd .ssh
touch authorized_keys
cat ~/id_rsa.pub >> ~/.ssh/authorized_keys
rm ~/id_rsa.pub

最后加上权限

chmod 600 ~/.ssh/authorized_keys
chmod 700 ~/.ssh

开启授权登陆

su
yum install vim
vim /etc/ssh/sshd_config

将如下三行注释去掉

RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile      .ssh/authorized_keys

如图所示

不建议使用root用户开启远程SSH登陆，如果实在想开启可以去掉

#PermitRootLogin yes

的注释

最后重启服务

service sshd restart

最后你会发现，已经不用输入密码了

ssh andy@192.168.1.104