Github 链接已有仓库时的认证，是通过使用SSH 的公开密钥认证的。
首先，创建SSH Key ，语法：
$ ssh-keygen -t rsa -C "content neirong"
-t ：密钥的类型
-C : 用于识别密钥的注释
-C 一般大家都写的是Email邮箱
以下小者测试的例子：
$ ssh-keygen -t rsa -C "add wm public ssh"
Generating public/private rsa key pair.
Enter file in which to save the key (/c/Users/xx/.ssh/id_rsa):
Created directory '/c/Users/\351\207\212\345\246\202\347\247\230/.ssh'.
下面是要输入的密码：
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /c/Users/xx/.ssh/id_rsa
Your public key has been saved in /c/Users/xx/.ssh/id_rsa.pub
The key fingerprint is:
SHA256:NGpvF0aaCWM5LsyZz6uTsqPI1UxEiLI9xCOEXdcIDX4 add wm public ssh
The key's randomart image is:
+---[RSA 3072]----+
|o+..==.o |
|+.=o..o.. |
|.= ...E o . |
|. oo.* * * |
| .*.+ S o |
| += . . . |
| . +o o . |
|o + o o . |
|oo.+.o. |
+----[SHA256]-----+
小者设置的密码是空。
id_rsa 文件是私有密钥，id_rsa.pub是公开密钥。
查看公开密钥的方法：
$ cat ~/.ssh/id_rsa.pub
把本地设置的公开密钥添加至GitHub中。
现在验证一下用手中的私有密钥与GitHub进行认证和通信了。
语法：
$ ssh -T
[email protected] The authenticity of host 'github.com (xx.xx.xx.xx)' can't be established.
RSA key fingerprint is SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8.
This key is not known by any other names
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes (这里输入yes)
出现以下说明成功通信：
Hi xxx! You've successfully authenticated, but GitHub does not provide shell access.
若有不当之处，敬请原谅。