WhatsApp/Signal/Formstack/admin updates

apps/link/app/api/formstack/route.ts

@@ -0,0 +1,98 @@
+import { NextRequest, NextResponse } from "next/server";
+import { createLogger } from "@link-stack/logger";
+import { getWorkerUtils } from "@link-stack/bridge-common";
+import { timingSafeEqual } from "crypto";
+
+// Force this route to be dynamic (not statically generated at build time)
+export const dynamic = 'force-dynamic';
+
+const logger = createLogger('formstack-webhook');
+
+export async function POST(req: NextRequest): Promise<NextResponse> {
+  try {
+    const clientIp = req.headers.get('x-forwarded-for') || req.headers.get('x-real-ip') || 'unknown';
+
+    // Get the shared secret from environment variable
+    const expectedSecret = process.env.FORMSTACK_SHARED_SECRET;
+
+    if (!expectedSecret) {
+      logger.error('FORMSTACK_SHARED_SECRET environment variable is not configured');
+      return NextResponse.json(
+        { error: "Server configuration error" },
+        { status: 500 }
+      );
+    }
+
+    // Get the shared secret from the request body
+    const body = await req.json();
+    const receivedSecret = body.HandshakeKey;
+
+    // Validate that secret is provided
+    if (!receivedSecret || typeof receivedSecret !== 'string') {
+      logger.warn({ clientIp }, 'Missing or invalid HandshakeKey');
+      return NextResponse.json(
+        { error: "Unauthorized" },
+        { status: 401 }
+      );
+    }
+
+    // Use timing-safe comparison to prevent timing attacks
+    const expectedBuffer = Buffer.from(expectedSecret);
+    const receivedBuffer = Buffer.from(receivedSecret);
+
+    let secretsMatch = false;
+    if (expectedBuffer.length === receivedBuffer.length) {
+      try {
+        secretsMatch = timingSafeEqual(expectedBuffer, receivedBuffer);
+      } catch (e) {
+        secretsMatch = false;
+      }
+    }
+
+    if (!secretsMatch) {
+      logger.warn({
+        secretMatch: false,
+        timestamp: new Date().toISOString(),
+        userAgent: req.headers.get('user-agent'),
+        clientIp
+      }, 'Invalid shared secret received');
+      return NextResponse.json(
+        { error: "Unauthorized" },
+        { status: 401 }
+      );
+    }
+
+    // Log webhook receipt with non-PII metadata only
+    logger.info({
+      formId: body.FormID,
+      uniqueId: body.UniqueID,
+      timestamp: new Date().toISOString(),
+      fieldCount: Object.keys(body).length
+    }, 'Received Formstack webhook');
+
+    // Enqueue a bridge-worker task to process this form submission
+    const worker = await getWorkerUtils();
+    await worker.addJob('formstack/create-ticket-from-form', {
+      formData: body,
+      receivedAt: new Date().toISOString(),
+    });
+
+    logger.info('Formstack webhook task enqueued successfully');
+
+    return NextResponse.json({
+      status: "success",
+      message: "Webhook received and queued for processing"
+    });
+
+  } catch (error) {
+    logger.error({
+      error: error instanceof Error ? error.message : error,
+      stack: error instanceof Error ? error.stack : undefined,
+    }, 'Error processing Formstack webhook');
+
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}