使用openssh实现免密码登录，免用户名+密码登录

    有时候经常登录某台主机，会懒得输入密码，输入个用户名登录，像我这种更懒的，密码也懒得输入：

  

    

• 使用openssh实现免密码登录（仅输入用户名就可以了）

  原理：使用公钥认证(私钥加密公钥解密可以进行身份验证)

  客户端生成一对密钥（public key和private key），通过将生成的公钥保存到需要认证的服务器的~/.ssh/authriedkey文件中，并且将.ssh目录的权限设置为644、authrizedkey权限设置为600即可

  ---

    ssh密钥生成

HuaiqingdeMBP:vagrant huaiqingcheng$ ssh-keygen -t rsa

Generating public/private rsa key pair.

Enter file in which to save the key (/Users/huaiqingcheng/.ssh/id_rsa): 

/Users/huaiqingcheng/.ssh/id_rsa already exists.

Overwrite (y/n)? y

Enter passphrase (empty for no passphrase): 

Enter same passphrase again: 

Your identification has been saved in /Users/huaiqingcheng/.ssh/id_rsa.

Your public key has been saved in /Users/huaiqingcheng/.ssh/id_rsa.pub.

The key fingerprint is:

SHA256:CCRo8ATutB5d8kXw2ApP0i2EB3yoPzWkPOnkjXHX4fw [e-mail]

The key's randomart image is:

+---[RSA 2048]----+

|+o+.=o..         |

|o+ *o+*  .       |

|.o++B* =+ .      |

|o.oBO=+o +       |

| +=.B++ S .      |

|. .* .     E     |

| .  .            |

|                 |

|                 |

+----[SHA256]-----+

    

    ssh-copy-id 复制公钥（需要输入一次用户密码）

    

HuaiqingdeMBP:vagrant huaiqingcheng$ ssh-copy-id root@192.168.0.113

/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/Users/huaiqingcheng/.ssh/id_rsa.pub"

/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed

/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys

root@192.168.0.113's password: 

Number of key(s) added:        1

Now try logging into the machine, with:   "ssh 'root@192.168.0.113'"

and check to make sure that only the key(s) you wanted were added.

    测试完成，免密码，需要输入用户名：

HuaiqingdeMBP:vagrant huaiqingcheng$ ssh root@192.168.0.113

Last login: Mon Mar 27 14:30:10 2017

Welcome to your Vagrant-built virtual machine.

[root@bogon ~]# 

      

或者手动复制公钥/Users/huaiqingcheng/.ssh/id_rsa.pub到目标虚机/root/.ssh/authorized_keys文件中，~/.ssh目录的权限700，authorized_key的权限为600

    

• 用openssh实现免用户名+密码登录

在～/.ssh/目录下建立config文件,编辑内容，绑定用户名和公钥

        Host 192.168.0.113 #

        HostName 192.168.0.113 #FQDN或者IP

        User root

        Port 22

        IdentityFile    ~/.ssh/id_rsa #公钥位置

    测试

HuaiqingdeMBP:vagrant huaiqingcheng$ ssh 192.168.0.113

Last login: Mon Mar 27 14:33:19 2017 from 192.168.0.101

Welcome to your Vagrant-built virtual machine.

[root@bogon ~]#