fix: Rewrite request with a root path to OIDC Provider

* fix(oidc): rewrite requests with rootpath

* fix: respect query parameters

src/identity/OidcHttpHandler.ts

@@ -18,6 +18,13 @@ export class OidcHttpHandler extends HttpHandler {
 
   public async handle({ request, response }: HttpHandlerInput): Promise<void> {
     const provider = await this.providerFactory.getProvider();
+
+    // Rewrite requests to allow hosting on root paths
+    const path = new URL(provider.issuer).pathname;
+    if (path.length > 1 && request.url!.startsWith(`${path}.well-known/openid-configuration`)) {
+      request.url = request.url!.replace(path, '/');
+    }
+
     this.logger.debug(`Sending request to oidc-provider: ${request.url}`);
     // Even though the typings do not indicate this, this is a Promise that needs to be awaited.
     // Otherwise, the `BaseHttpServerFactory` will write a 404 before the OIDC library could handle the response.