Secure CRT 7.0遠端Kali 2020版本時，報錯

Key exchange failed.
No compatible key exchange method. The server supports these methods: curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256
 

錯誤原因是SecureCRT 7.0客戶端支援的和kali作為ssh服務端支援的SSH祕鑰交換演算法不匹配。
Secure CRT 7.0的預設支援key exchange演算法：

 

顯然是不在Kali 2020版本預設支援的dh-g1-sha256,dh-g16-sha512,dh-g18-sha512,dh-g14-sha256這些組合範圍內的。

處理辦法
修改/etc/ssh/sshd_config配置檔案,增加如下一行，使新版本的Kali Linux支援老版本的祕鑰交換演算法。

KexAlgorithms [email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1

補充內容
檢視伺服器支援的祕鑰交換演算法
nmap --script ssh2-enum-algos -sV -p <port> <host>

root@kali:~# nmap --script ssh2-enum-algos -sV -p 22 localhost
Starting Nmap 7.80 ( https://nmap.org ) at 2020-08-10 02:08 CDT
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000064s latency).
Other addresses for localhost (not scanned): ::1
 


PORT   STATE SERVICE VERSION
22/tcp open  ssh     OpenSSH 8.3p1 Debian 1 (protocol 2.0)
| ssh2-enum-algos: 
|   kex_algorithms: (8)
|       curve25519-[email protected]
|       ecdh-sha2-nistp256
|       ecdh-sha2-nistp384
|       ecdh-sha2-nistp521
|       diffie-hellman-group-exchange-sha256
|       diffie-hellman-group14-sha1
|       diffie-hellman-group-exchange-sha1
|       diffie-hellman-group1-sha1
|   server_host_key_algorithms: (5)
|       rsa-sha2-512
|       rsa-sha2-256
|       ssh-rsa
|       ecdsa-sha2-nistp256
|       ssh-ed25519
|   encryption_algorithms: (6)
|       chacha20-[email protected]
|       aes128-ctr
|       aes192-ctr
|       aes256-ctr
|       aes128-[email protected]
|       aes256-[email protected]
|   mac_algorithms: (10)
|       umac-64-[email protected]
|       umac-128-[email protected]
|       hmac-sha2-256-[email protected]
|       hmac-sha2-512-[email protected]
|       hmac-sha1-[email protected]
|       umac-64@openssh.com
|       umac-128@openssh.com
|       hmac-sha2-256
|       hmac-sha2-512
|       hmac-sha1
|   compression_algorithms: (2)
|       none
|_      [email protected]
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel