feat: allow requesting scopes when using ExchangedTokenRequestedEvent event

lib/Event/ExchangedTokenRequestedEvent.php

@@ -20,6 +20,7 @@ class ExchangedTokenRequestedEvent extends Event {
 
 	public function __construct(
 		private string $targetAudience,
+		private array $extraScopes = [],
 	) {
 		parent::__construct();
 	}
@@ -32,6 +33,10 @@ public function setTargetAudience(string $targetAudience): void {
 		$this->targetAudience = $targetAudience;
 	}
 
+	public function getExtraScopes(): array {
+		return $this->extraScopes;
+	}
+
 	public function getToken(): ?Token {
 		return $this->token;
 	}

lib/Listener/ExchangedTokenRequestedListener.php

@@ -37,10 +37,11 @@ public function handle(Event $event): void {
 		}
 
 		$targetAudience = $event->getTargetAudience();
+		$extraScopes = $event->getExtraScopes();
 		$this->logger->debug('[ExchangedTokenRequestedListener] received request for audience: ' . $targetAudience);
 
 		// classic token exchange with an external provider
-		$token = $this->tokenService->getExchangedToken($targetAudience);
+		$token = $this->tokenService->getExchangedToken($targetAudience, $extraScopes);
 		$event->setToken($token);
 	}
 }

lib/Service/TokenService.php

@@ -220,7 +220,7 @@ public function decodeIdToken(Token $token): array {
 	 * @throws TokenExchangeFailedException
 	 * @throws \JsonException
 	 */
-	public function getExchangedToken(string $targetAudience): Token {
+	public function getExchangedToken(string $targetAudience, array $extraScopes = []): Token {
 		$storeLoginTokenEnabled = $this->config->getAppValue(Application::APP_ID, 'store_login_token', '0') === '1';
 		if (!$storeLoginTokenEnabled) {
 			throw new TokenExchangeFailedException(
@@ -240,6 +240,10 @@ public function getExchangedToken(string $targetAudience): Token {
 		}
 		$oidcProvider = $this->providerMapper->getProvider($loginToken->getProviderId());
 		$discovery = $this->discoveryService->obtainDiscovery($oidcProvider);
+		$scope = $oidcProvider->getScope();
+		if (!empty($extraScopes)) {
+			$scope .= ' ' . implode(' ', $extraScopes);
+		}
 
 		try {
 			$clientSecret = $oidcProvider->getClientSecret();
@@ -267,6 +271,7 @@ public function getExchangedToken(string $targetAudience): Token {
 						// this one will get us an access token and refresh token within the response
 						'requested_token_type' => 'urn:ietf:params:oauth:token-type:refresh_token',
 						'audience' => $targetAudience,
+						'scope' => $scope,
 					],
 				]
 			);