概念

SSH全称安全外壳（Secure Shell）协议，这个协议的目的就是为了取代缺乏机密性保障的远程管理协议，SSH基于TCP协议的加密通道，让客户端使用服务器的RSA公钥来验证SSHv2服务器的身份。

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创建密钥对

在充当SSH服务器的路由器上创建本地密钥对；本例中是AR1充当服务器，AR4充当客户端。

密钥对是一个公钥一个密钥，信息用公钥加密就用私钥解密，服务器会将公钥给客户端，客户端使用私钥加密数据之后，数据只能服务器的私钥才能解开，确保了数据安全性。

 

[AR1]rsa local-key-pair create 
The key name will be: Host
% RSA keys defined for Host already exist.
Confirm to replace them? (y/n)[n]:y
The range of public key size is (512 ~ 2048).
NOTES: If the key modulus is greater than 512,
       It will take a few minutes.
Input the bits in the modulus[default = 512]:512
Generating keys...
.............++++++++++++
.++++++++++++
................................................................................
.................++++++++
.........++++++++

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启用SSH服务器进程

路由器默认 SSH服务是没开启的，需要手动开启。

[AR1]stelnet server enable 
Info: Succeeded in starting the STELNET server.

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修改VTY虚拟接口的入站协议

# SSH协议支持的认证模式只有aaa
[AR1]user-interface vty 0 4
[AR1-ui-vty0-4]authentication-mode aaa

# VTY接口允许接受的入站协议修改为SSH    
[AR1-ui-vty0-4]protocol inbound ssh

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设置aaa参数

# 创建的用户名为user1，密码为huawei  
[AR1]aaa     
[AR1-aaa]local-user user1 password cipher huawei
Info: Add a new user.

# 指定这个用户使用的协议，只能是ssh
[AR1-aaa]local-user user1 service-type ssh

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设置SSH的认证类型

[AR1]ssh user user1 authentication-type ?
  all           All authentication, password or RSA
  password      Password authentication
  password-rsa  Both password and RSA
  rsa           RSA authentication
 
[AR1]ssh user user1 authentication-type password
 Authentication type setted, and will be in effect next time

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AR4（client）访问AR1（Server）

尝试连接时系统提示错误同时要求管理员运行， "ssh client first-time enable" 才能开启首次访问功能，没有这条命令那么服务器发给客户端的公钥，客户端无法保存，所以这才命令在SSH客户端上必不可少。

[AR4]stelnet 192.168.28.1
Please input the username:user1
Trying 192.168.28.1 ...
Press CTRL+K to abort
Connected to 192.168.28.1 ...
Error: Failed to verify the server's public key.
Please run the command "ssh client first-time enable"to enable the first-time ac
cess function and try again.

# 会报错

 启用SSH首次访问功能并连接SSH服务器

[AR4]ssh client first-time enable 
[AR4]stelnet 192.168.28.1
Please input the username:user1
Trying 192.168.28.1 ...
Press CTRL+K to abort
Connected to 192.168.28.1 ...
The server is not authenticated. Continue to access it? (y/n)[n]:y
Mar 28 2023 17:25:32-08:00 AR4 %%01SSH/4/CONTINUE_KEYEXCHANGE(l)[0]:The server h
ad not been authenticated in the process of exchanging keys. When deciding wheth
er to continue, the user chose Y. 
[AR4]
Save the server's public key? (y/n)[n]:y
The server's public key will be saved with the name 192.168.28.1. Please wait...

Mar 28 2023 17:25:34-08:00 AR4 %%01SSH/4/SAVE_PUBLICKEY(l)[1]:When deciding whet
her to save the server's public key 192.168.28.1, the user chose Y. 
[AR4]
Enter password:
<AR1>

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查看SSH状态、SSH访问情况

# 在服务器上查看SSH状态，显示SSH的版本，显示SSH的功能是否启用
[AR1] display ssh server status 
 SSH version                         :1.99  
 SSH connection timeout              :60 seconds
 SSH server key generating interval  :0 hours
 SSH Authentication retries          :3 times
 SFTP Server                         :Disable
 Stelnet server                      :Enable     

 # 查看会话
[AR1] display ssh server session 
 --------------------------------------------------------------------
 Conn   Ver   Encry     State  Auth-type        Username
 --------------------------------------------------------------------
 VTY 1  2.0   AES       run    password         user1                           
 --------------------------------------------------------------------
[AR1]