调用github API使用github OauthAPP实现网站授权登录功能

1. Request a user’s GitHub identity（请求一个github用户的id）
   GET https://github.com/login/oauth/authorize
   When your GitHub App specifies a login parameter, it prompts users with a specific account they can use for signing in and authorizing your app.

Parameters(参数)

state:防止跨站点攻击
allow_signup：此参数可选填

1. Users are redirected back to your site by GitHub（用户被github重定向到你的站点）
   If the user accepts your request, GitHub redirects back to your site with a temporary code in a code parameter as well as the state you provided in the previous step in a state parameter. The temporary code will expire after 10 minutes. If the states don’t match, then a third party created the request, and you should abort the process.

Exchange this code for an access token:

POST https://github.com/login/oauth/access_token
Response
By default, the response takes the following form:

access_token=e72e16c7e42f292c6912e7710c838347ae178b4a&token_type=bearer
3. Use the access token to access the API
The access token allows you to make requests to the API on a behalf of a user.

Authorization: token OAUTH-TOKEN
GET https://api.github.com/user
For example, in curl you can set the Authorization header like this:

curl -H “Authorization: token OAUTH-TOKEN” https://api.github.com/user