# Set single SSH key & multi-SSH keys for GitHub
> Date : 2017/08/30
> Author : Traveler
> Email : [e-mail]
---
## Steps
1. Create GitHub account.
2. Generate SSH key for Github

    ssh-keygen -t rsa -b 4096 -C "[e-mail]" -f ~/.ssh/github

3. Look and copy SSH public key.

    cat ~/.ssh/github.pub

4. Import SSH public key on GitHub.
1. copy the public key(plain text)
2. paste the public key on Github settings page.
5. Generate SSH config for Github

    vi ~/.ssh/config

Copy below config for Github

    HostName github.com
    User git
    IdentityFile ~/.ssh/github
    Port 22

6. Checking SSH connection.

    # base syntax
    ssh -T user@hostname
    # An example by default.
    ssh -T [e-mail]
    # An example by github config
    ssh -T github
    # An example by self-defined host name, 
    # noticed: you should set Host: githib.com-hello, for example: Host [e-mail]-hello
    ssh -T [e-mail]-hello
    
    # If you intend to test connection by verbos, just attach -v, for example,
    ssh -vT [e-mail]

If connection is ok, you can see `Hi (your name)! You've successfully authenticated, but GitHub does not provide shell access.`
7. If you need to set multi SSH keys, you can try to add config file. That will be separted from Host(a kind of alias).

    touch ~/.ssh/config
    vi ~/.ssh/config

And then you can add below configure into the config file.

    Host hello
	HostName github.com
	User git
	IdentityFile ~/.ssh/github

Below is a command for customized Host.

    ssh -T hello
    ssh -vt hello

### Reference
1. [GitHub設定指引](http://wiki.csie.ncku.edu.tw/github)
2. [SSH Keys for GitHub](https://jdblischak.github.io/2014-09-18-chicago/novice/git/05-sshkeys.html)
3. [多重 SSH Keys 與 Github 帳號](https://kuanyui.github.io/2016/08/01/git-multiple-ssh-key/)