IT IS NOT POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY
someone could be eavesdropping on your right now (man-in-the-middle attack !)
it is also possible that the RSA host key has been changed
解决方法:
进入 ~/.ssh目录，编辑known_host文件，删除其中包括你想连接的主机的那一行，存盘再连接.ok.