Initial independent version of CrAPP

src/lib/webpush.server.ts

@@ -0,0 +1,77 @@
+/** Invio di notifiche web push (senza payload) firmate con VAPID, compatibile con il runtime edge. */
+
+function base64UrlDecode(value: string): Uint8Array {
+  const padding = "=".repeat((4 - (value.length % 4)) % 4);
+  const base64 = (value + padding).replace(/-/g, "+").replace(/_/g, "/");
+  const raw = atob(base64);
+  const out = new Uint8Array(raw.length);
+  for (let i = 0; i < raw.length; i += 1) out[i] = raw.charCodeAt(i);
+  return out;
+}
+
+function base64UrlEncode(bytes: Uint8Array): string {
+  let binary = "";
+  bytes.forEach((b) => {
+    binary += String.fromCharCode(b);
+  });
+  return btoa(binary).replace(/\+/g, "-").replace(/\//g, "_").replace(/=+$/, "");
+}
+
+function encodeJson(value: unknown): string {
+  return base64UrlEncode(new TextEncoder().encode(JSON.stringify(value)));
+}
+
+async function importaChiave(publicKey: string, privateKey: string) {
+  const pub = base64UrlDecode(publicKey);
+  return crypto.subtle.importKey(
+    "jwk",
+    {
+      kty: "EC",
+      crv: "P-256",
+      d: privateKey,
+      x: base64UrlEncode(pub.slice(1, 33)),
+      y: base64UrlEncode(pub.slice(33, 65)),
+      ext: true,
+    },
+    { name: "ECDSA", namedCurve: "P-256" },
+    false,
+    ["sign"],
+  );
+}
+
+async function creaVapidJwt(audience: string, subject: string, publicKey: string, privateKey: string) {
+  const header = encodeJson({ typ: "JWT", alg: "ES256" });
+  const payload = encodeJson({
+    aud: audience,
+    exp: Math.floor(Date.now() / 1000) + 12 * 60 * 60,
+    sub: subject,
+  });
+  const chiave = await importaChiave(publicKey, privateKey);
+  const firma = await crypto.subtle.sign(
+    { name: "ECDSA", hash: "SHA-256" },
+    chiave,
+    new TextEncoder().encode(`${header}.${payload}`),
+  );
+  return `${header}.${payload}.${base64UrlEncode(new Uint8Array(firma))}`;
+}
+
+/** Invia una notifica "vuota": il service worker recupera poi il testo aggiornato. */
+export async function inviaPush(endpoint: string): Promise<number> {
+  const publicKey = process.env["VAPID_PUBLIC_KEY"];
+  const privateKey = process.env["VAPID_PRIVATE_KEY"];
+  const subject = process.env["VAPID_SUBJECT"] ?? "mailto:crapp@crapvolley.it";
+  if (!publicKey || !privateKey) throw new Error("Chiavi VAPID non configurate");
+
+  const audience = new URL(endpoint).origin;
+  const jwt = await creaVapidJwt(audience, subject, publicKey, privateKey);
+
+  const res = await fetch(endpoint, {
+    method: "POST",
+    headers: {
+      TTL: "86400",
+      Authorization: `vapid t=${jwt}, k=${publicKey}`,
+      "Content-Length": "0",
+    },
+  });
+  return res.status;
+}