Centos7 免密码SSH双向登录

短命女 2022-05-29 06:46 288阅读 0赞

#### 服务器：   Master   IP：192.168.2.66   Slave1    IP：192.168.2.10   Slave2    IP：192.168.2.18 ####

#### 一、首先实现单向Master可以免密码ssh登录slave1和slave2 ####

##### 1、到三台服务器的用户家目录检查是否存在.ssh，如果没有则需要手动创建。这里使用root用户演示 #####

[root@master ~]# ls
    drwx------.  2 root root 4096 Mar 19 15:50 .ssh

##### 2、生成ssh公钥、私钥文件 #####

[root@master ~]# cd .ssh/
    [root@master .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:
    SHA256:UXhkXi1bx/a3jrSoHYhu6C+vD2cWnd67rBjpQEiSk3w root@master
    The key's randomart image is:
    +---[RSA 2048]----+
    |         o+ .. . |
    |. o     .+... o +|
    | * E    ...  + o.|
    |  = .   ... .   o|
    |   . . .So      o|
    |    .   = o  . . |
    |     o.B o oo +  |
    |     oO.o o.oo . |
    |    .oBB oo=.    |
    +----[SHA256]-----+

##### 无需输入任何信息，一路回车即可，生成完成后会在用户根路径下的ssh目录（cd ~/.ssh）发现：id\_rsa、id\_rsa.pub两个文件； #####

[root@master .ssh]# ll
    total 8
    -rw------- 1 root root    0 Mar 19 15:50 authorized_keys
    -rw------- 1 root root 1675 Mar 19 17:26 id_rsa
    -rw-r--r-- 1 root root  393 Mar 19 17:26 id_rsa.pub

##### 3、将master的公钥追加至slave1服务器authorized\_keys文件，slave2同理拷贝master公钥到authorized\_keys。（ssh-copy-id -i ~/.ssh/id\_rsa.pub root@192.168.2.10） #####

[root@master ~]# cd .ssh/
    [root@master .ssh]# scp id_rsa.pub root@192.168.2.10:~/.ssh/authorized_keys 
    The authenticity of host '192.168.2.10 (192.168.2.10)' can't be established.
    ECDSA key fingerprint is SHA256:ZTtQLCTg21cYLQ5iJa5LkC51xN6lKGxVyLRAxjXPUOw.
    ECDSA key fingerprint is MD5:6d:5b:e9:d9:bd:12:64:06:c5:cc:a2:07:a6:99:96:3d.
    Are you sure you want to continue connecting (yes/no)? yes
    Warning: Permanently added '192.168.2.10' (ECDSA) to the list of known hosts.
    root@192.168.2.10's password: 
    id_rsa.pub                                                                                                 100%  393     1.2MB/s   00:00

##### 4、测试可以登录 #####

[root@master .ssh]# ssh 192.168.2.10
    Last login: Mon Mar 19 21:07:28 2018 from 59.42.207.235
    [root@slave1 ~]#

[root@master .ssh]# ssh 192.168.2.18
    Last login: Mon Mar 19 21:07:33 2018 from 113.109.21.73
    [root@slave2 ~]#

##### 5、如果不可以登录，就需要检查文件，文件夹权限 #####

[root@master ~]# chmod 700 .ssh
    [root@master ~]# chmod 600 .ssh/authorized_keys

#### 二、双向登录，slave服务器也能登录master服务器 ####

##### 1、基本步骤跟上面的一致，只是拷贝slave服务器的公钥到master的时候，先分开命名，要不第二个就会覆盖第一个导致第一个无法登录 #####

[root@slave1 .ssh]# scp id_rsa.pub root@192.168.2.66:~/.ssh/authorized_keys_slave1
    root@192.168.2.66's password: 
    id_rsa.pub                                                                                                 100%  393     0.4KB/s   00:00

[root@slave2 .ssh]# scp id_rsa.pub root@192.168.2.66:~/.ssh/authorized_keys_slave2
    The authenticity of host '192.168.2.66 (192.168.2.66)' can't be established.
    ECDSA key fingerprint is b8:0f:8c:d2:9f:10:65:22:73:ea:ea:02:75:89:5d:98.
    Are you sure you want to continue connecting (yes/no)? yes
    Warning: Permanently added '192.168.2.66' (ECDSA) to the list of known hosts.
    root@192.168.2.66's password: 
    id_rsa.pub                                                                                                 100%  393     0.4KB/s   00:00

##### 2、回到master服务器把authorized.keys\_（slave1和slave2）文件追加为一个authorized.keys文件 #####

[root@master .ssh]# ll
    total 24
    -rw------- 1 root root  393 Mar 19 17:29 authorized_keys
    -rw-r--r-- 1 root root  393 Mar 19 21:30 authorized_keys_slave1
    -rw-r--r-- 1 root root  393 Mar 19 21:32 authorized_keys_slave2
    -rw------- 1 root root 1675 Mar 19 17:26 id_rsa
    -rw-r--r-- 1 root root  393 Mar 19 17:26 id_rsa.pub
    -rw-r--r-- 1 root root  348 Mar 19 21:21 known_hosts

[root@master .ssh]# cat authorized_keys_slave1 >> authorized_keys
    [root@master .ssh]# cat authorized_keys_slave2 >> authorized_keys

##### 合并之后可以删除authorized\_keys\_\*文件 #####

##### 3、slave1和slave2测试登录master成功 #####

[root@slave1 .ssh]# ssh 192.168.2.66
    Last failed login: Mon Mar 19 21:32:10 CST 2018 from 192.168.2.10 on ssh:notty
    There were 2 failed login attempts since the last successful login.
    Last login: Mon Mar 19 21:28:38 2018 from 113.109.21.73
    [root@master ~]#

[root@slave2 .ssh]# ssh 192.168.2.66
    Last login: Mon Mar 19 21:36:32 2018 from 192.168.2.10
    [root@master ~]#