SSH 免密码登陆

1、master上生产公钥、私钥对

[root@XXX213 .ssh]# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): 
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
b4:1a:63:57:80:d7:cd:cb:5c:ac:ab:b1:aa:7e:11:7d root@XXX
The key's randomart image is:
+--[ RSA 2048]----+
|       ... o .   |
|      . ... o o  |
|       ....o +   |
|       ..o. E    |
|      + S. . .   |
|     . =. . .    |
|      .  . +     |
|        . o      |
|     .oo..       |
+-----------------+

2、将公钥发送给slave，并追加到/root/.ssh/authorized_keys 文件中

cat id_rsa.pub >> /root/.ssh/authorized_keys 
 chmod 600 /root/.ssh/authorized_keys  #注意对其他组\其他用户不给任何读写权限

3、master能够实现免密码SSH登陆slave

[root@XXX213 .ssh]# ssh 192.168.10.214 -p 222
Last login: Thu Apr  6 12:43:16 2017 from 192.168.10.213
[root@XXX214 ~]#

注意：

     1、master采用 生成ssh-genkey 使用的账号登陆slave。

　　2、master将自己的公钥追加到本地的authorized_keys 也能够实现自己登陆自己免密码。