Implement basic OIDC core server handling

apps/oauth2/lib/Controller/OauthApiController.php

@@ -35,6 +35,8 @@
 use OCP\AppFramework\Http\JSONResponse;
 use OCP\AppFramework\Utility\ITimeFactory;
 use OCP\IRequest;
+use OCP\IURLGenerator;
+use OCP\IUserManager;
 use OCP\Security\ICrypto;
 use OCP\Security\ISecureRandom;
 
@@ -53,6 +55,10 @@ class OauthApiController extends Controller {
 	private $time;
 	/** @var Throttler */
 	private $throttler;
+	/** @var IUserManager */
+	private $userManager;
+	/** @var IURLGenerator */
+	private $urlGenerator;
 
 	public function __construct(string $appName,
 								IRequest $request,
@@ -62,7 +68,9 @@ public function __construct(string $appName,
 								TokenProvider $tokenProvider,
 								ISecureRandom $secureRandom,
 								ITimeFactory $time,
-								Throttler $throttler) {
+								Throttler $throttler,
+								IUserManager $userManager,
+								IURLGenerator $urlGenerator) {
 		parent::__construct($appName, $request);
 		$this->crypto = $crypto;
 		$this->accessTokenMapper = $accessTokenMapper;
@@ -71,6 +79,8 @@ public function __construct(string $appName,
 		$this->secureRandom = $secureRandom;
 		$this->time = $time;
 		$this->throttler = $throttler;
+		$this->userManager = $userManager;
+		$this->urlGenerator = $urlGenerator;
 	}
 
 	/**
@@ -161,6 +171,7 @@ public function getToken($grant_type, $code, $refresh_token, $client_id, $client
 		$this->accessTokenMapper->update($accessToken);
 
 		$this->throttler->resetDelay($this->request->getRemoteAddress(), 'login', ['user' => $appToken->getUID()]);
+		$jwt = $this->getIdToken($client_id, $appToken, $client);
 
 		return new JSONResponse(
 			[
@@ -169,7 +180,66 @@ public function getToken($grant_type, $code, $refresh_token, $client_id, $client
 				'expires_in' => 3600,
 				'refresh_token' => $newCode,
 				'user_id' => $appToken->getUID(),
+				'id_token' => $jwt,
 			]
 		);
 	}
+
+	/**
+	 * @param $client_id
+	 * @param \OC\Authentication\Token\IToken $appToken
+	 * @param \OCA\OAuth2\Db\Client $client
+	 * @return string
+	 */
+	private function getIdToken($client_id, \OC\Authentication\Token\IToken $appToken, \OCA\OAuth2\Db\Client $client)
+	{
+		// The id token needs to be correctly build as JWT. Taken from https://dev.to/robdwaller/how-to-create-a-json-web-token-using-php-3gml
+
+		// Create token header as a JSON string
+		$header = json_encode(['typ' => 'JWT', 'alg' => 'HS256']);
+
+		// We need the user to fill in name and email in the id_token
+		$user = $this->userManager->get($appToken->getUID());
+
+		// Create token payload as a JSON string
+		$payload = json_encode([
+			// required for OIDC, see https://openid.net/specs/openid-connect-core-1_0.html#IDToken
+			// Issuer Identifier for the Issuer of the response.
+			'iss' => $this->urlGenerator->getBaseUrl(),
+			// Subject Identifier. A locally unique and never reassigned identifier within the Issuer for the End-User, which is intended to be consumed by the Client
+			'sub' => $appToken->getUID(),
+			// Audience(s) that this ID Token is intended for. It MUST contain the OAuth 2.0 client_id of the Relying Party as an audience value.
+			'aud' => $client_id,
+			// Expiration time on or after which the ID Token MUST NOT be accepted for processing.
+			'exp' => $appToken->getExpires(),
+			// Time at which the JWT was issued.
+			'iat' => $this->time->getTime(),
+			// Time when the End-User authentication occurred.
+			'auth_time' => $this->time->getTime(),
+
+			// optional, can be requested by claims, we don't support requesting claims as of now, so we just send them always
+			// see https://openid.net/specs/openid-connect-core-1_0.html#StandardClaims
+			// End-User's preferred e-mail address.
+			'email' => $user->getEMailAddress(),
+			// End-User's full name in displayable form including all name parts, possibly including titles and suffixes
+			'name' => $user->getDisplayName(),
+
+		]);
+
+		// Encode Header to Base64Url String
+		$base64UrlHeader = str_replace(['+', '/', '='], ['-', '_', ''], base64_encode($header));
+
+		// Encode Payload to Base64Url String
+		$base64UrlPayload = str_replace(['+', '/', '='], ['-', '_', ''], base64_encode($payload));
+
+		// Create Signature Hash
+		$signature = hash_hmac('sha256', $base64UrlHeader . "." . $base64UrlPayload, $client->getSecret(), true);
+
+		// Encode Signature to Base64Url String
+		$base64UrlSignature = str_replace(['+', '/', '='], ['-', '_', ''], base64_encode($signature));
+
+		// Create JWT
+		$jwt = $base64UrlHeader . "." . $base64UrlPayload . "." . $base64UrlSignature;
+		return $jwt;
+	}
 }

apps/oauth2/tests/Controller/OauthApiControllerTest.php

@@ -37,6 +37,9 @@
 use OCP\AppFramework\Http\JSONResponse;
 use OCP\AppFramework\Utility\ITimeFactory;
 use OCP\IRequest;
+use OCP\IURLGenerator;
+use OCP\IUser;
+use OCP\IUserManager;
 use OCP\Security\ICrypto;
 use OCP\Security\ISecureRandom;
 use Test\TestCase;
@@ -58,6 +61,10 @@ class OauthApiControllerTest extends TestCase {
 	private $time;
 	/** @var Throttler|\PHPUnit_Framework_MockObject_MockObject */
 	private $throttler;
+	/** @var IUserManager|\PHPUnit_Framework_MockObject_MockObject */
+	private $userManager;
+	/** @var IURLGenerator|\PHPUnit_Framework_MockObject_MockObject */
+	private $urlGenerator;
 	/** @var OauthApiController */
 	private $oauthApiController;
 
@@ -72,6 +79,8 @@ public function setUp() {
 		$this->secureRandom = $this->createMock(ISecureRandom::class);
 		$this->time = $this->createMock(ITimeFactory::class);
 		$this->throttler = $this->createMock(Throttler::class);
+		$this->userManager = $this->createMock(IUserManager::class);
+		$this->urlGenerator = $this->createMock(IURLGenerator::class);
 
 		$this->oauthApiController = new OauthApiController(
 			'oauth2',
@@ -82,7 +91,9 @@ public function setUp() {
 			$this->tokenProvider,
 			$this->secureRandom,
 			$this->time,
-			$this->throttler
+			$this->throttler,
+			$this->userManager,
+			$this->urlGenerator
 		);
 	}
 
@@ -281,12 +292,25 @@ public function testGetTokenValidAppToken() {
 				})
 			);
 
+		$this->urlGenerator->method('getBaseUrl')
+			->willReturn('http://localhost');
+
 		$expected = new JSONResponse([
 			'access_token' => 'random72',
 			'token_type' => 'Bearer',
 			'expires_in' => 3600,
 			'refresh_token' => 'random128',
 			'user_id' => 'userId',
+			'id_token' => $this->encodeJWT(json_encode([
+				'iss' => 'http://localhost',
+				'sub' => 'userId',
+				'aud' => 'clientId',
+				'exp' => 4600,
+				'iat' => 1000,
+				'auth_time' => 1000,
+				'email' => null,
+				'name' => null
+			]), 'clientSecret')
 		]);
 
 		$this->request->method('getRemoteAddress')
@@ -300,6 +324,13 @@ public function testGetTokenValidAppToken() {
 				['user' => 'userId']
 			);
 
+		$user = $this->createMock(IUser::class);;
+
+		$this->userManager->expects($this->once())
+			->method('get')
+			->with('userId')
+			->willReturn($user);
+
 		$this->assertEquals($expected, $this->oauthApiController->getToken('refresh_token', null, 'validrefresh', 'clientId', 'clientSecret'));
 	}
 
@@ -373,12 +404,25 @@ public function testGetTokenValidAppTokenBasicAuth() {
 				})
 			);
 
+		$this->urlGenerator->method('getBaseUrl')
+			->willReturn('http://localhost');
+
 		$expected = new JSONResponse([
 			'access_token' => 'random72',
 			'token_type' => 'Bearer',
 			'expires_in' => 3600,
 			'refresh_token' => 'random128',
 			'user_id' => 'userId',
+			'id_token' => $this->encodeJWT(json_encode([
+				'iss' => 'http://localhost',
+				'sub' => 'userId',
+				'aud' => 'clientId',
+				'exp' => 4600,
+				'iat' => 1000,
+				'auth_time' => 1000,
+				'email' => null,
+				'name' => null
+			]), 'clientSecret'),
 		]);
 
 		$this->request->server['PHP_AUTH_USER'] = 'clientId';
@@ -395,6 +439,13 @@ public function testGetTokenValidAppTokenBasicAuth() {
 				['user' => 'userId']
 			);
 
+		$user = $this->createMock(IUser::class);;
+
+		$this->userManager->expects($this->once())
+			->method('get')
+			->with('userId')
+			->willReturn($user);
+
 		$this->assertEquals($expected, $this->oauthApiController->getToken('refresh_token', null, 'validrefresh', null, null));
 	}
 
@@ -468,12 +519,25 @@ public function testGetTokenExpiredAppToken() {
 				})
 			);
 
+		$this->urlGenerator->method('getBaseUrl')
+			->willReturn('http://localhost');
+
 		$expected = new JSONResponse([
 			'access_token' => 'random72',
 			'token_type' => 'Bearer',
 			'expires_in' => 3600,
 			'refresh_token' => 'random128',
 			'user_id' => 'userId',
+			'id_token' => $this->encodeJWT(json_encode([
+				'iss' => 'http://localhost',
+				'sub' => 'userId',
+				'aud' => 'clientId',
+				'exp' => 4600,
+				'iat' => 1000,
+				'auth_time' => 1000,
+				'email' => null,
+				'name' => null
+			]), 'clientSecret'),
 		]);
 
 		$this->request->method('getRemoteAddress')
@@ -487,6 +551,33 @@ public function testGetTokenExpiredAppToken() {
 				['user' => 'userId']
 			);
 
+		$user = $this->createMock(IUser::class);;
+
+		$this->userManager->expects($this->once())
+			->method('get')
+			->with('userId')
+			->willReturn($user);
+
 		$this->assertEquals($expected, $this->oauthApiController->getToken('refresh_token', null, 'validrefresh', 'clientId', 'clientSecret'));
 	}
+
+	private function encodeJWT($payload, $secret) {
+		// Create token header as a JSON string
+		$header = json_encode(['typ' => 'JWT', 'alg' => 'HS256']);
+
+		// Encode Header to Base64Url String
+		$base64UrlHeader = str_replace(['+', '/', '='], ['-', '_', ''], base64_encode($header));
+
+		// Encode Payload to Base64Url String
+		$base64UrlPayload = str_replace(['+', '/', '='], ['-', '_', ''], base64_encode($payload));
+
+		// Create Signature Hash
+		$signature = hash_hmac('sha256', $base64UrlHeader . "." . $base64UrlPayload, $secret, true);
+
+		// Encode Signature to Base64Url String
+		$base64UrlSignature = str_replace(['+', '/', '='], ['-', '_', ''], base64_encode($signature));
+
+		// Create JWT
+	   return $base64UrlHeader . "." . $base64UrlPayload . "." . $base64UrlSignature;
+	}
 }