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Linux系统SSH服务之 sshkey密钥认证实战
前面介绍了SSH服务一些特性及其简单配置，在实际的生产环境中，经常会用到sshkey密钥认证实行数据分发数据等操作，还可以批量操作内网服务器，实行免密认证进行推送分发数据
实际生产结构拓扑图如下
**整个配置过程**
整个配置环境只用一两台服务器
一、实际环境查看
分发服务器
[root@Centos ~]# cat /etc/redhat-release
CentOS release 6.5 (Final)
[root@localhost ~]# uname -r
2.6.32-431.el6.x86_64
节点服务器
[root@localhost ~]# cat /etc/redhat-release
CentOS release 6.5 (Final)
[root@localhost ~]# uname -r
2.6.32-431.el6.x86_64
二、服务器添加系统账号
分发服务端配置账号与密码
[root@Centos ~]# useradd fenfa
[root@Centos ~]# echo “123456”|passwd –stdin fenfa
Changing password for user fenfa.
passwd: all authentication tokens updated successfully.
节点服务端配置账号与密码
[root@localhost ~]# useradd fenfa
[root@localhost ~]# echo “123456”|passwd –stdin fenfa
Changing password for user fenfa.
passwd: all authentication tokens updated successfully
三、生成密钥对
注意此操作需切换到创建的用户（分发服务器操作）
[root@Centos ~]# su - fenfa
[fenfa@Centos ~]$ whoami
fenfa
[fenfa@Centos ~]$ ssh-keygen -t dsa
Generating public/private dsa key pair.
Enter file in which to save the key (/home/fenfa/.ssh/id_dsa):
key存储到这个文件
Created directory ‘/home/fenfa/.ssh’. 系统自动创建这个目录
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/fenfa/.ssh/id_dsa. 私钥
Your public key has been saved in /home/fenfa/.ssh/id_dsa.pub.公钥
The key fingerprint is:
07:06:7a:22:ec:11:72:ae:06:36:de:1c:17:15:90:50 fenfa@Centos
The key’s randomart image is:
+–[ DSA 1024]—-+
|. o.oE=o. |
| = . o.. |
|.o=.o.. o |
|+o+ooo . . |
|.o.o S . |
|. . |
| |
| |
| |
+—————–+
[fenfa@Centos ~]$ cd /home/fenfa/.ssh
[fenfa@Centos ~]$ ls -ld .ssh
drwx——. 2 fenfa fenfa 4096 Aug 27 17:09 .ssh 权限700
[fenfa@Centos .ssh]$ ls -ll
total 8
-rw——-. 1 fenfa fenfa 672 Aug 27 16:47 id_dsa
-rw-r–r–. 1 fenfa fenfa 602 Aug 27 16:47 id_dsa.pub
**此处注意两个文件的权限：id_dsa 600 id_dsa.pub 644 **
[fenfa@Centos ~]$ cat /home/fenfa/.ssh/id_dsa
—–BEGIN DSA PRIVATE KEY—–
MIIBvAIBAAKBgQCtz936+YRJaeXBdaVxAtCXOy7IzpUbKSLLA+IC2bg6xLOGS8U+
5qvI73eQqr2yB0HIowEfVSX51zAZShj3SPe3dO89UjD2R+PHL9ORPx2MNLed9MVS
gVFOd12OmsAJ+CDsoFV8J1iF0rjbfZ1XDwCPtktWfG5xnOwjtKSHt9aNVQIVAJ4j
t8J7fuQq40QH6KQ3iEwrupVHAoGAXO3Gel3jQTjN4HJAoWW1zloHlZiD8IkJ6Uz+
LJl6uKFh2klhT+2G9ndOezQlpcMPh/8EOADPZwo+wFRCcKrXoe9ugl/YKb0ERZrn
7ZwEe/uvg1ciW9bCeigni24PMEtiPCd8vDpaSKCkdp7EEvAX/HjaVkUNdALqMl0j
s93UAlICgYEAhQEfTIzZitAyx72z7Bdwtc3FLiPgIGu2vX2mu0xRz4sMHbBOBRi2
a+LFvrwCSfizXO1HBB+giAH2GUFu4BRfxfwHcBRtGtynjMsNlfvU72JBvVVE8puv
BW4A3+5dSUW1skllBuFzkbLQOnhi7SFboSGIXqRSI3NAfutPJ/5Id8MCFQCNVrXo
HcHsd+7aKJql1oW10MHxBQ==
—–END DSA PRIVATE KEY—–
四、分发密钥（公钥）
分发的命令格式
ssh-copy-id -i 密钥名称 用户@远端主机IP地址————-用于ssh是默认端口
ssh-copy-id -i 密钥名称 “-p port 用户@远端主机IP地址”–用于ssh非默认端口
[fenfa@Centos ~]$ cd .ssh
[fenfa@Centos .ssh]$ ssh-copy-id -i id_dsa.pub fenfa@192.168.1.3
The authenticity of host ‘192.168.1.3 (192.168.1.3)’ can’t be established.
RSA key fingerprint is 86:41:46:5c:d9:e0:98:a5:15:ee:b4:01:a5:37:49:c4.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added ‘192.168.1.3’ (RSA) to the list of known hosts.
fenfa@192.168.1.3‘s password:
Now try logging into the machine, with “ssh ‘fenfa@192.168.1.3‘“, and check in:
** .ssh/authorized_keys**
to make sure we haven’t added extra keys that you weren’t expecting.
节点服务器测试是否分发成功
[root@localhost ~]# tree /home/fenfa/.ssh/
/home/fenfa/.ssh/
+– authorized_keys
0 directories, 1 file
分发成功
五、分发数据
手工分发
[fenfa@Centos ]$ scp -P22 -r -p /tmp/text/ fenfa@192.168.1.3:
123.txt 100% 0 0.0KB/s 00:00
节点服务器测试
[root@localhost fenfa]# tree /home/fenfa/
/home/fenfa/
+– text
+– 123.txt
1 directory, 1 file
脚本分发
可以将命令写进脚本中进行执行
[fenfa@Centos ~]$ vi fenfa.sh
scp -P22 -r -p /tmp/text/ fenfa@192.168.1.3:/tmp/fenfadir/
[fenfa@Centos ~]$ ./fenfa.sh
123.txt 100% 0 0.0KB/s 00:00
[fenfa@localhost fenfadir]$ pwd
/tmp/fenfadir
[fenfa@localhost fenfadir]$ tree
.
+– text
+– 123.txt
1 directory, 1 file
分发成功
如果是生产环境中每天都要分发一些数据到节点服务器，可以将此脚本放进定时任务，每天系统自动执行，不过最好定时执行的时间是服务并发量不高的时候，以免影响正常的业务访问
