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。
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...
.............++++++++++++
.++++++++++++
................................................................................
.................++++++++
.........++++++++
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.
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
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
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
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>
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]
