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
