生成身份验证密钥
ssh-keygen -t rsa，在~/.ssh/目录下生成私匙id_rsa和公匙id_rsa.pub两个文件。
$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/username/.ssh/id_rsa): 直接回车
Enter passphrase (empty for no passphrase): 直接回车
Enter same passphrase again: 直接回车
Your identification has been saved in /home/username/.ssh/id_rsa.
Your public key has been saved in /home/username/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:foo-YWwIv/a/HGEGt9P6vvmff/QjBGEvzlYM4hBWeR0 username@hostname
The key's randomart image is:
+---[RSA 2048]----+
| +oo.ooE.|
| . o..o+. |
| . . .. .+ |
| . o o o.o |
| o o S . +. |
| o =+ + .. ..|
| + .+ . . o..|
| o .o = . + .o|
| . o+o=o+o. o..|
+----[SHA256]-----+
复制您的公匙 id_rsa.pub 到服务器，命名为 authorized_keys。
$ scp .ssh/id_rsa.pub username@hostname:/home/username/.ssh/authorized_keys
ssh 登录可以不用输入密码直接登录服务器了。
$ ssh username@hostname