feature: the beginnings of chat working

public/js/totp.js

@@ -0,0 +1,42 @@
+/* https://github.com/turistu/totp-in-javascript/blob/main/totp.js */
+
+async function otp_totp(key, secs = 30, digits = 6) {
+	return otp_hotp(otp_unbase32(key), otp_pack64bu(Date.now() / 1000 / secs), digits);
+}
+async function otp_hotp(key, counter, digits) {
+	let y = self.crypto.subtle;
+	if (!y) throw Error("no self.crypto.subtle object available");
+	let k = await y.importKey("raw", key, { name: "HMAC", hash: "SHA-1" }, false, ["sign"]);
+	return otp_hotp_truncate(await y.sign("HMAC", k, counter), digits);
+}
+function otp_hotp_truncate(buf, digits) {
+	let a = new Uint8Array(buf),
+		i = a[19] & 0xf;
+	return otp_fmt(
+		10,
+		digits,
+		(((a[i] & 0x7f) << 24) | (a[i + 1] << 16) | (a[i + 2] << 8) | a[i + 3]) % 10 ** digits,
+	);
+}
+
+function otp_fmt(base, width, num) {
+	return num.toString(base).padStart(width, "0");
+}
+function otp_unbase32(s) {
+	let t = (s.toLowerCase().match(/\S/g) || [])
+		.map((c) => {
+			let i = "abcdefghijklmnopqrstuvwxyz234567".indexOf(c);
+			if (i < 0) throw Error(`bad char '${c}' in key`);
+			return otp_fmt(2, 5, i);
+		})
+		.join("");
+	if (t.length < 8) throw Error("key too short");
+	return new Uint8Array(t.match(/.{8}/g).map((d) => parseInt(d, 2)));
+}
+function otp_pack64bu(v) {
+	let b = new ArrayBuffer(8),
+		d = new DataView(b);
+	d.setUint32(0, v / 2 ** 32);
+	d.setUint32(4, v);
+	return b;
+}