# OAuth2 Handler

## Presentation

This Handler is able to check an OAuth2 access token to retrieve the user real session and protect a virtual host like a standard Handler (access control and HTTP headers transmission).

This requires to get an OAuth2 access token through LL::NG Portal (OpenID Connect server). This access token can then be used in the `Authorization` header to authenticate to the Web Service / API protected by the OAuth2 Handler.

Tip

In the above schema, the OpenID Connect process is simplified. How the front application receives the Access Token depends on the requested flow (Authorization code, Implicit or Hybrid). In all cases, the application will have an Access Token and will be able to use it to request a Web Service.

Example:

    curl -H "Authorization: Bearer de853461341e88e9def8fcb9db2a81c4" https://oauth2.example.com/api/test | json_pp

    {
        check: true,
        user: "dwho"
    }

## Additional variables

The OAuth2 handler defines a few extra variables that you can use in rules and headers.

- `$_clientId`: client ID of the application which requested the Access Token

- `$_clientConfKey`: configuration key of the application which requested the Access Token

- `$_scope`: list of space-separated scopes granted by the Access Token

For example, to grant access to access tokens containing the `write` scope, use

    $_scope =~ /(?<!\S)write(?!\S)/

## Configuration

Protect you virtual host like any other virtual host with the standard Handler.

Define access rules and headers. Then in `Options` > `Type`, choose `OAuth2`.

## Reference

RFC6750