远程主机的RSA key是怎么生成的，盼大师指点

ray7hu

root@E520:/home/ray# ssh root@192.168.100.44
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    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 RSA key sent by the remote host is
fb:37:3f:d6:c3:66:8f:60:92:57:1d:3f:5a:a6:32:9f.
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /root/.ssh/known_hosts:9
  remove with: ssh-keygen -f "/root/.ssh/known_hosts" -R 192.168.100.44
RSA host key for 192.168.100.44 has changed and you have requested strict checking.
Host key verification failed.

下面的命令可以清掉指定的key，登陆时重新生成key
root@E520:/home/ray# ssh-keygen -f "/root/.ssh/known_hosts" -R 192.168.100.44

但不知道这个key是根据什么生成的，又如可验证它已经改变了

q1208c

sshd 在第一次运行的时候, 会生成本机的 key pair.