BUG：WSL 的 ssh server 没法启动

BUG

使用 sudo service ssh start 启动 ssh 服务，提示：

* Restarting OpenBSD Secure Shell server sshd                   
Could not load host key: /etc/ssh/ssh_host_rsa_key
Could not load host key: /etc/ssh/ssh_host_ecdsa_key
Could not load host key: /etc/ssh/ssh_host_ed25519_key
                                                          [ OK ]

而后使用 powershell 链接，提示 refused:

PS C:\Users\suyua> ssh ryan@localhost
ssh: connect to host localhost port 22: Connection refused

FIX

卸载重装 openssh-server:

sudo apt-get purge openssh-server  # purge 是卸载并删除配置文件
sudo apt-get install openssh-server

而后修改 /etc/ssh/sshd_config 的下列几行参数：

#Port 22   # 若是端口冲突，就须要修改这个
ListenAddress localhost  # 只接受本地请求
PasswordAuthentication yes  # 容许密码登陆

重启 ssh 服务：

sudo service ssh restart

而后链接：

PS C:\Users\suyua> ssh ryan@localhost
ryan@localhost's password:
Welcome to Ubuntu 18.04.2 LTS (GNU/Linux 4.4.0-17763-Microsoft x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

......

问题解决。

参考

-windows-wsl sshd配置