事情是这样的，刚刚在 PowerShell 中使用 SSH 连接一台运行在虚拟机中的 Ubuntu 主机，然后提示主机指纹信息验证失败，可能遭受中间人攻击：
PS C:Users86188> ssh -l mk 192.168.88.128 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that a host key has just been changed. The fingerprint for the ECDSA key sent by the remote host is SHA256:xGND4WU3/ONKL9tz4XKvXqrzisqD34/JuaNk1RtuApo. Please contact your system administrator. Add correct host key in C:\Users\86188/.ssh/known_hosts to get rid of this message. Offending ECDSA key in C:\Users\86188/.ssh/known_hosts:5 ECDSA host key for 192.168.88.128 has changed and you have requested strict checking. Host key verification failed.
呃，我回想了一下，之前复制过一台 Ubuntu 虚拟机，其 IP 地址和我现在这台一样。
估计是因为我曾经连接过那一台虚拟机，在用户目录下的 .sshknown_hosts 文件中保存了它的指纹信息，导致这次连接这台新的虚拟机时，SSH 检测到指纹信息不匹配，才出现这种提示。
如果真的是这样，那么我只要删除 .sshknown_hosts 文件中相关的指纹信息，应该就可以解决这个问题。
在 PowerShell 中使用 Get-Content 命令查看 .sshknown_hosts 文件中的指纹信息：
PS C:Users86188.ssh> Get-Content .known_hosts ****** # 其他指纹信息 192.168.88.128 ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBGhhhMvqg0UZXfE+Ao//g9o8BXQr2VHCYPO4wttAs1CsDLtpYebOR/dLsQpudp50dESivx3OBM+hlokkoMKr3AQ= ****** # 其他指纹信息
果然有一条关于 192.168.88.128 主机的指纹信息。编辑文件，将其删除。
然后，重新使用 SSH 尝试连接 192.168.88.128 主机：
PS C:Users86188.ssh> ssh -l mk 192.168.88.128 The authenticity of host '192.168.88.128 (192.168.88.128)' can't be established. ECDSA key fingerprint is SHA256:xGND4WU3/ONKL9tz4XKvXqrzisqD34/JuaNk1RtuApo. Are you sure you want to continue connecting (yes/no/[fingerprint])? yes Warning: Permanently added '192.168.88.128' (ECDSA) to the list of known hosts. mk@192.168.88.128's password: ****** Welcome to Ubuntu 22.04 LTS (GNU/Linux 5.15.0-27-generic x86_64) * Documentation: https://help.ubuntu.com * Management: https://landscape.canonical.com * Support: https://ubuntu.com/advantage 39 updates can be applied immediately. To see these additional updates run: apt list --upgradable The programs included with the Ubuntu system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law.
嗯，顺利连上。
