SSH密钥创建分发

Linux, OS系统 / 作者：
1.1 服务端端口号变化了，如何基于秘钥连接

1.1.1 环境准备

实验环境：

[root@test ~]# cat /etc/redhat-release
CentOS release 6.9 (Final)

将一台服务器的ssh服务端口修改为63389

[root@test ~]# netstat -lntup|grep sshd
tcp        0      0 0.0.0.0:63389  0.0.0.0:*         LISTEN      5083/sshd          
tcp        0      0 :::63389         :::*              LISTEN      5083/sshd

1.1.2 通过另外一台服务器创建并分发密钥

第一个里程碑： 现创建密钥使用 ssh-keygen

[root@backup ~]# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):   #指定密钥对的保存路径
Enter passphrase (empty for no passphrase):        #为密钥对创建密码
Enter same passphrase again:                          #确认为密钥对创建的密码
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:
72:48:65:1d:25:69:e1:4c:ae:2b:6f:a5:aa:70:96:1e root@backup
The key's randomart image is:
+--[ RSA 2048]----+     #2048表示加密的位数为2048位
|        o.==.      |
|       o =+.       |
|      .  .+        |
|     . . .         |
|      o S           |
|     . o ..        |
|  . E . .o         |
|   = . oo           |
|    o..o.           |
+-----------------+

第二个里程碑：分发密钥，注意ssh的端口

[root@backup ~]# ssh-copy-id  -i ~/.ssh/id_rsa.pub "-p63389 172.16.1.250"
The authenticity of host '[172.16.1.250]:63389 ([172.16.1.250]:63389)' can't be established.
RSA key fingerprint is d3:41:bb:0d:43:88:da:a3:2c:e8:36:91:11:c9:e4:9c.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '[172.16.1.250]:63389' (RSA) to the list of known hosts.
root@172.16.1.250's password:
Now try logging into the machine, with "ssh '-p63389 172.16.1.250'", and check in:
 
  .ssh/authorized_keys   #分发到对端服务器后进行改名

to make sure we haven't added extra keys that you weren't expecting.

说明：

通过 man 手册找到密钥分发的命令格式。

-i 参数指定 公钥文件的存放位置

[use@]表示使用的用户，默认使用当前登陆的用户

-p 指定端口，主要要在双引号之间（通过cat `which ssh-copy-id` 命令脚本内容得知）

[root@backup ~]# man ssh-copy-id

Formatting page, please wait…

SSH-COPY-ID(1)                                                  SSH-COPY-ID(1)

NAME

ssh-copy-id  –  install  your  public  key in a remote machine’s autho-

rized_keys

SYNOPSIS

第三个里程碑： 测试密钥登陆

[root@backup ~]# ssh 172.16.1.250 -p 63389
Last login: Wed Oct 18 15:42:05 2017 from 10.0.0.41

[root@test ~]#

1.2 如何实现自动创建秘钥对，同时分发公钥（编写脚本实现）

脚本内容：

[root@m01 ~]# vim /server/scripts/piliang_fenfa.sh 
  1 #!/bin/bash
  2 
  3 #make key
  4 \rm -f /root/.ssh/id_dsa
  5 ssh-keygen -t dsa -f /root/.ssh/id_dsa -P "" -q
  6 
  7 #fengfagongyao
  8 for ip in 8 31 41
  9 do
 10 echo ====fenfa key to host 172.16.1.$ip====
 11 sshpass -p123456 ssh-copy-id -i /root/.ssh/id_dsa.pub "-o StrictHostKeyChecking=no root@172.16.1.$ip"
 12 echo ===============fenfa end==============
 13 echo ""
 14 done

脚本说明：

   ssh-keygen -t dsa -f /root/.ssh/id_dsa -P "" -q

创建密钥，-f指定存放位置，-P 密钥加密的密码  -q 减少信息输出

sshpass -p123456 ssh-copy-id -i /root/.ssh/id_dsa.pub "-o StrictHostKeyChecking=no root@172.16.1.$ip"

这里需要安装一个软件 yum install sshpass -y 用来提供中户密码

ssh-copy-id 命令来分发密钥 -i 指定密钥本地存放的路径

-o StrictHostKeyChecking=no 在登陆其他服务器是不选择yes/no

for ip in 8 31 41

这里使用for循环来对ip地址进行变化。

附录：CentOS 7密钥分发脚本

 1 #!/bin/bash
 2 . /etc/rc.d/init.d/functions
 3 
 4 yum install sshpass -y  >/dev/null
 5 # 创建密钥
 6 \rm ~/.ssh/id_rsa* -f
 7 ssh-keygen -t rsa -f ~/.ssh/id_rsa -N "" -q
 8 # 分发公钥
 9 for ip in 61 21 51 31 41 8 7 9 5 6 
10 do
11 sshpass -p123456 ssh-copy-id -o "StrictHostKeyChecking no"  -i /root/.ssh/id_rsa.pub 172.16.1.$ip &>/dev/null
12 if [ $? -eq 0 ];then
13 action  "fenfa 172.16.1.$ip"  /bin/true
14 else
15 action  "fenfa 172.16.1.$ip"  /bin/false
16 fi
17 echo ""
18 done

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