git ssh key for github

第一：检查.ssh是否存在(ls -al ~/.ssh)

$ ls -al ~/.ssh
Lists the files in your .ssh directory, if they exist

第二：产生新的SSH key(ssh-keygen -t rsa -C "your_email@example.com")

$ ssh-keygen -t rsa -C "your_email@example.com"
Creates a new ssh key, using the provided email as a label
Generating public/private rsa key pair.
Enter file in which to save the key (/c/Users/you/.ssh/id_rsa): [Press enter]

Enter passphrase (empty for no passphrase): [Type a passphrase][Press enter]

Enter same passphrase again: [Type passphrase again][Press enter]

产生的结果如下：

Your identification has been saved in /c/Users/you/.ssh/id_rsa.
Your public key has been saved in /c/Users/you/.ssh/id_rsa.pub.
The key fingerprint is:
01:0f:f4:3b:ca:85:d6:17:a1:7d:f0:68:9d:f0:a2:db your_email@example.com

添加新的key到ssh-agent:

$ ssh-agent -s
Agent pid 59566
$ ssh-add ~/.ssh/id_rsa

如果出现Could not open a connection to your authentication agent
解决办法：
$ eval $(ssh-agent)
Agent pid 59566
$ ssh-add ~/.ssh/id_rsa
Identity added:/c/Users/you/.ssh/id_rsa(/c/Users/you/.ssh/id_rsa) 

第三：添加ssh key到github中

$ clip < ~/.ssh/id_rsa.pub
Copies the contents of the id_rsa.pub file to your clipboard
如下图所示：

第四：检查如否配置成功

在Git Bash中输入：

$ ssh -T git@github.com
Attempts to ssh to github

或许会出现：

The authenticity of host 'github.com (207.97.227.239)' can't be established.
RSA key fingerprint is 16:27:ac:a5:76:28:2d:36:63:1b:56:4d:eb:df:a6:48.
Are you sure you want to continue connecting (yes/no)?

这是正常的，输入yes即可

Hi username! You've successfully authenticated, but GitHub does not
provide shell access.

第五：改变git的remote url：将https://github.com/xxxx.git改成git@github.com:xxxx.git

即修改.git/config文件

文章摘自：https://help.github.com/articles/generating-ssh-keys