[Linux专题] SSH使用

SSH介绍

SSH为Secure Shell的缩写,为建立在应用层基础上的安全协议.支持口令以及秘钥方式登录.默认使用22端口.支持RSA和DSA两种秘钥方式.

SSH服务端

Ubuntu及CentOS服务端安装命令如下,默认在安装服务器端时一并安装SSH客户端：
```
[CentOS]
yum install openssh-server
[Ubuntu]
sudo apt install openssh-server
```

服务端SSH相关操作

//1 查看ssh服务是否启动 服务为sshd
yjf@vbox-ubuntu:~$ ps -ef|grep ssh
root      2846     1  0 06:50 ?        00:00:00 /usr/sbin/sshd -D

//2 查看sshd服务使用的端口
yjf@vbox-ubuntu:~$ sudo netstat -lntup | grep ssh
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      2846/sshd

//3 秘钥目录为~/.ssh/目录
//4 sshd的配置文件：
yjf@vbox-ubuntu:~$ sudo cat /etc/ssh/sshd_config 

//5 相关服务的开启 状态查看等命令
yjf@vbox-ubuntu:~$ sudo systemctl status sshd
yjf@vbox-ubuntu:~$ sudo systemctl restart sshd
yjf@vbox-ubuntu:~$ sudo systemctl enable sshd

SSH客户端

SSH的客户端可以用XSHELL，Securecrt, Mobaxterm等工具进行连接,也可以使用最简单的ssh命令进行连接.(Windows平台安装Git软件后自带ssh工具)

用户名密码验证方式

//1 ssh客户端直接登录方式
ccczyl2006@ccczyl2006-PC MINGW64 ~/Desktop
$ ssh -p22 yjf@192.168.0.106
The authenticity of host '192.168.0.106 (192.168.0.106)' can't be established.
ECDSA key fingerprint is SHA256:pr62XwLtsc2zRRMsP5x78RZVBU6EAwjXukuiauMO0RI.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.0.106' (ECDSA) to the list of known hosts.
yjf@192.168.0.106's password:

xshell密码登录.新建连接后进行用户名和密码登录

秘钥验证方式

//1 进入用户根目录下的.ssh目录，使用命令生成公钥和秘钥(注意Enter passphrase输入的是私钥的密码 可以留空)
$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/c/Users/ccczyl2006/.ssh/id_rsa): vbox-ubun                                                       tu_rsa
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in vbox-ubuntu_rsa.
Your public key has been saved in vbox-ubuntu_rsa.pub.
The key fingerprint is:
SHA256:giIl8zh168hymZJNocd3c4bOBJfX1kzNVo7ugfT/TdE ccczyl2006@ccczyl2006-PC
The key's randomart image is:
+---[RSA 2048]----+
|            .o ..|
|       . . +  +o |
|o + o o . o +.. .|
| X o = o . . +  .|
|= * + * S   . +.E|
| O B = =     . o.|
|+ B . o       . o|
| +             .o|
|                o|
+----[SHA256]-----+

//2 生成的文件带.pub为公钥 另一个文件为私钥
$ ll
total 15
-rw-r--r-- 1 ccczyl2006 197121   73 四月 11 15:44  config
-rw-r--r-- 1 ccczyl2006 197121  118 四月 25  2018 'config - Copy'
drwxr-xr-x 1 ccczyl2006 197121    0 四月 11 20:51  copy/
-rw-r--r-- 1 ccczyl2006 197121 6755 四月 11 19:56  known_hosts
-rw-r--r-- 1 ccczyl2006 197121 1679 四月 11 20:56  vbox-ubuntu_rsa
-rw-r--r-- 1 ccczyl2006 197121  406 四月 11 20:56  vbox-ubuntu_rsa.pub

//2 使用ssh-copy-id 命令拷贝公钥到服务器 
$ ssh-copy-id -i vbox-ubuntu_rsa.pub yjf@192.168.0.106
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "vbox-ubuntu_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
yjf@192.168.0.106's password:

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'yjf@192.168.0.106'"
and check to make sure that only the key(s) you wanted were added.

//3 登录服务器确保.ssh目录下已存在authorized_keys文件 

//4 存放私有的文件夹.ssh下使用以下命令即可使用无密码访问
$ ssh -i ./vbox-ubuntu_rsa yjf@192.168.0.106

xshell私有访问如下图

最后编辑于：2019.11.09 19:50:07