import * as http from 'http'; import { URL } from 'url'; /** * Ephemerer HTTP-Server auf localhost:PORT fuer OAuth-Redirect-Capture. * RFC 8252 (OAuth 2.0 for Native Apps) — System-Browser + Loopback-Redirect. * * Lifecycle: * const server = await startLoopbackServer({ pathPrefix: '/oauth/callback' }); * console.log(server.url); // http://127.0.0.1:54321/oauth/callback * const params = await server.awaitParams({ timeoutMs: 5 * 60 * 1000 }); * server.close(); * * Bindet immer auf 127.0.0.1 (nicht 0.0.0.0) — der OS-Listener ist nur lokal * erreichbar, kein Firewall-Prompt unter Windows. */ export interface LoopbackServerOptions { pathPrefix: string; // z.B. '/oauth/callback' port?: number; // 0 = OS waehlt freien Port successHtml?: string; // HTML-Antwort beim Capture errorHtml?: string; } export interface LoopbackServer { readonly url: string; awaitParams(opts?: { timeoutMs?: number }): Promise; close(): void; } const DEFAULT_SUCCESS = `Login erfolgreich

Login erfolgreich

Du kannst dieses Fenster jetzt schliessen.

`; const DEFAULT_ERROR = `Fehler

Fehler

`; export function startLoopbackServer(opts: LoopbackServerOptions): Promise { const successHtml = opts.successHtml ?? DEFAULT_SUCCESS; const errorHtml = opts.errorHtml ?? DEFAULT_ERROR; const pathPrefix = opts.pathPrefix.startsWith('/') ? opts.pathPrefix : '/' + opts.pathPrefix; return new Promise((resolve, reject) => { let resolveCapture: ((p: URLSearchParams) => void) | null = null; let rejectCapture: ((e: Error) => void) | null = null; let captureSettled = false; const captureP = new Promise((res, rej) => { resolveCapture = res; rejectCapture = rej; }); const server = http.createServer((req, res) => { try { const url = new URL(req.url || '/', 'http://127.0.0.1'); if (!url.pathname.startsWith(pathPrefix)) { res.writeHead(404, { 'Content-Type': 'text/plain' }); res.end('not found'); return; } const params = url.searchParams; const hasError = params.has('error'); res.writeHead(200, { 'Content-Type': 'text/html; charset=utf-8' }); res.end(hasError ? errorHtml : successHtml); if (!captureSettled && resolveCapture) { captureSettled = true; resolveCapture(params); } } catch (e) { res.writeHead(500, { 'Content-Type': 'text/plain' }); res.end('internal error'); if (!captureSettled && rejectCapture) { captureSettled = true; rejectCapture(e instanceof Error ? e : new Error(String(e))); } } }); server.on('error', reject); server.listen(opts.port ?? 0, '127.0.0.1', () => { const addr = server.address(); if (!addr || typeof addr === 'string') { server.close(); reject(new Error('loopback-server: failed to determine bound port')); return; } const url = `http://127.0.0.1:${addr.port}${pathPrefix}`; resolve({ url, async awaitParams(awaitOpts) { const timeoutMs = awaitOpts?.timeoutMs ?? 5 * 60 * 1000; let timer: NodeJS.Timeout | null = null; const timeoutP = new Promise((_, rej) => { timer = setTimeout(() => { if (!captureSettled && rejectCapture) { captureSettled = true; rejectCapture(new Error('loopback-server: timeout waiting for redirect')); } rej(new Error('loopback-server: timeout waiting for redirect')); }, timeoutMs); }); try { return await Promise.race([captureP, timeoutP]); } finally { if (timer) clearTimeout(timer); } }, close() { try { server.close(); } catch { /* already closed */ } }, }); }); }); }