ssh-keygen -C "634772208@qq.com" -t rsa
时，出现如下错误：
cygwin Could not create directory '/home/Administrator/.ssh'
解决方案：
In addition to answer by diannal, if you don't have a passwd file under etc folder in Cygwin root folder, then you can first create one by issuing this command:
mkpasswd -l -p "$(cygpath -H)" > /etc/passwd
运行以上命令就解决了
参考：
http://superuser.com/questions/517619/cygwin-cannot-create-ssh
https://peterreavy.wordpress.com/2012/05/22/fixing-could-not-create-directory-error-on-cygwin-ssh/
