配置ssh免密码登录

访问机(bainuo)

[jim@bainuo ~]$ ssh-keygen     //ssh-kengen等同于ssh-keygen -t rsa,默认就是rsa算法，还有一种就是dsa算法Generating public/private rsa key pair.Enter file in which to save the key (/home/jim/.ssh/id_rsa): Created directory '/home/jim/.ssh'.Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/jim/.ssh/id_rsa.Your public key has been saved in /home/jim/.ssh/id_rsa.pub.The key fingerprint is:

一路回车，在如下目录会生成文件

[jim@bainuo .ssh]$ pwd/home/jim/.ssh[jim@bainuo .ssh]$ lsid_rsa  id_rsa.pub

id_rsa ：私钥
id_rsa.pub ：公钥

然后就是将公钥复制到被访问机上(centos7)，有两种方法，一种是使用scp，一种是使用ssh-copy-id

使用ssh-copy-id，如果提示command not found，需要安装openssh-clients

[root@bainuo ~]# yum install openssh-clients -y

[jim@bainuo .ssh]$ ssh-copy-id terry@192.168.1.30The authenticity of host '192.168.1.30 (192.168.1.30)' can't be established.RSA key fingerprint is f2:57:ea:91:f2:b8:2f:9c:aa:99:7c:ee:a8:97:f6:91.Are you sure you want to continue connecting (yes/no)? yPlease type 'yes' or 'no': yesWarning: Permanently added '192.168.1.30' (RSA) to the list of known hosts.Nasty PTR record "192.168.1.30" is set up for 192.168.1.30, ignoringterry@192.168.1.30's password: Now try logging into the machine, with "ssh 'terry@192.168.1.30'", and check in:  .ssh/authorized_keysto make sure we haven't added extra keys that you weren't expecting.

测试一下

[jim@bainuo .ssh]$ ssh terry@192.168.1.30   //因为两边的用户名不一致，所以需要加上centos7上的用户名Nasty PTR record "192.168.1.30" is set up for 192.168.1.30, ignoringLast login: Sun Aug 20 15:25:22 2017[terry@centos7 ~]$ 

可以了，如果需要不加上用户名，两个办法

1.两处使用相同的用户名

2.在~/.ssh/目录下创建config文件，并修改文件权限为600

[jim@bainuo .ssh]$ chmod 600 config 

[jim@bainuo .ssh]$ cat config host 192.168.1.30user terry

然后就可以不加用户名直接连接了

[jim@bainuo .ssh]$ ssh 192.168.1.30Nasty PTR record "192.168.1.30" is set up for 192.168.1.30, ignoringLast login: Sun Aug 20 15:34:38 2017 from 192.168.1.20[terry@centos7 ~]$ 

接前面的话题，如果使用scp传送密匙的话，如下：

scp id_rsa.pub terry@192.168.1.30:/home/terry

然后在被访问机上导入密匙

cat ~/id_rsa.pub >> ~/.ssh/authorized_keys 

注意authorized_keys文件的权限也是设置为600