scala-oauth2-provider

# oauth2-server for Scala [![CI](https://github.com/nulab/scala-oauth2-provider/actions/workflows/ci.yml/badge.svg)](https://github.com/nulab/scala-oauth2-provider/actions/workflows/ci.yml)

[The OAuth 2.0](http://tools.ietf.org/html/rfc6749) server-side implementation written in Scala.

This provides OAuth 2.0 server-side functionality and supporting function for [Play Framework](http://www.playframework.com/) and [Akka HTTP](http://akka.io/).

The idea of this library originally comes from [oauth2-server](https://github.com/yoichiro/oauth2-server) which is Java implementation of OAuth 2.0.

## Supported OAuth features

This library supports all grant types.

- Authorization Code Grant (PKCE Authorization Code Grants are supported)
- Resource Owner Password Credentials Grant
- Client Credentials Grant
- Implicit Grant

and an access token type called [Bearer](http://tools.ietf.org/html/rfc6750).

## Setup

### Play Framework

See [the project](https://github.com/nulab/play2-oauth2-provider)

### Akka HTTP

See [the project](https://github.com/nulab/akka-http-oauth2-provider)

### Other frameworks

Add `scala-oauth2-core` library dependencies of your project.
In this case, you need to implement your own OAuth provider working with web framework you use.

```scala
libraryDependencies ++= Seq(
  "com.nulab-inc" %% "scala-oauth2-core" % "1.6.0"
)
```

## How to use

### Implement DataHandler

Whether you use Play Framework or not, you have to implement `DataHandler` trait and make it work with your own `User` class that may be already defined in your application.

```scala
case class User(id: Long, name: String, hashedPassword: String)

class MyDataHandler extends DataHandler[User] {

  def validateClient(maybeClientCredential: Option[ClientCredential], request: AuthorizationRequest): Future[Boolean] = ???

  def findUser(maybeClientCredential: Option[ClientCredential], request: AuthorizationRequest): Future[Option[User]] = ???

  def createAccessToken(authInfo: AuthInfo[User]): Future[AccessToken] = ???

  def getStoredAccessToken(authInfo: AuthInfo[User]): Future[Option[AccessToken]] = ???

  def refreshAccessToken(authInfo: AuthInfo[User], refreshToken: String): Future[AccessToken] = ???

  def findAuthInfoByCode(code: String): Future[Option[AuthInfo[User]]] = ???

  def findAuthInfoByRefreshToken(refreshToken: String): Future[Option[AuthInfo[User]]] = ???

  def deleteAuthCode(code: String): Future[Unit] = ???

  def findAccessToken(token: String): Future[Option[AccessToken]] = ???

  def findAuthInfoByAccessToken(accessToken: AccessToken): Future[Option[AuthInfo[User]]] = ???

}
```

If your data access is blocking for the data storage, then you just wrap your implementation in the `DataHandler` trait with `Future.successful(...)`.

For more details, refer to Scaladoc of `DataHandler`.

### AuthInfo

`DataHandler` returns `AuthInfo` as authorized information.
`AuthInfo` is made up of the following fields.

```scala
case class AuthInfo[User](