Manjaro使用密钥登录SSH

为了方便在外面连接家里的Manjaro ARM小机，我打算把22端口转发出去，于是安全性有必要加强，使用密钥登录取代弱口令。

生产密钥

$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/marly/.ssh/id_rsa):
Created directory '/home/marly/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/marly/tmp/id_rsa
Your public key has been saved in /home/marly/tmp/id_rsa.pub
The key fingerprint is:
SHA256:FNPW7n5ub8l5PKn0/DZXQ7yK0ZqJyZJ9pLVFL6l6A2I marly@manjaro
The key's randomart image is:
+---[RSA 3072]----+
|        o. .     |
|         oo .    |
|        .. .  .  |
|       .    .. o |
|        S  .o + .|
|       E . +.= +.|
|      . = B.X.+.*|
|       o * @o.=B*|
|        ..+ .=o*O|
+----[SHA256]-----+
$ ls ~/.ssh
id_rsa  id_rsa.pub
$ cat ~/.ssh/id_rsa.pub>>authorized_key

公钥放在服务器上，私钥存放在本地用于登录，不要在服务器上存放。
另外权限需要格外注意，如果配置不当会产生许多问题，建议按如下配置（id_rsa不建议存储在服务器上）：

$ chmod 700 ~/.ssh
$ chmod 600 ~/.ssh/id_rsa
$ chmod 600 ~/.ssh/id_rsa.pub
$ chmod 600 ~/.ssh/authroized_keys

修改ssh_config

$ sudo vim /etc/ssh/sshd_config

主要确认这两行内容：

AuthorizedKeysFile .ssh/authorized_keys
PasswordAuthentication no

最后执行

$ sudo systemctl restart sshd.service

重启服务就完事了。