Add missing modules

packages/core/src/base32.ts

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+import { Err, ErrorCode } from "./error";
+
+const chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+
+export function bytesToBase32(arr: Uint8Array) {
+    let bits = 0;
+    let value = 0;
+    let str = "";
+
+    for (let i = 0; i < arr.length; i++) {
+        value = (value << 8) | arr[i];
+        bits += 8;
+
+        while (bits >= 5) {
+            str += chars[(value >>> (bits - 5)) & 31];
+            bits -= 5;
+        }
+    }
+
+    if (bits > 0) {
+        str += chars[(value << (5 - bits)) & 31];
+    }
+
+    return str;
+}
+
+export function base32ToBytes(str: string) {
+    const strUpp = str.toUpperCase();
+    const arr = new Uint8Array(((str.length * 5) / 8) | 0);
+
+    let bits = 0;
+    let value = 0;
+    let index = 0;
+
+    for (let i = 0; i < strUpp.length; i++) {
+        const idx = chars.indexOf(strUpp[i]);
+
+        if (idx === -1) {
+            throw new Err(ErrorCode.ENCODING_ERROR, `Invalid Base32 character found: ${strUpp[i]}`);
+        }
+
+        value = (value << 5) | idx;
+        bits += 5;
+
+        if (bits >= 8) {
+            arr[index++] = (value >>> (bits - 8)) & 255;
+            bits -= 8;
+        }
+    }
+
+    return arr;
+}

packages/core/src/otp.ts

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+import { numToBytes, bytesToNum } from "./encoding";
+import { getProvider, HMACParams } from "./crypto";
+import { base32ToBytes } from "./encoding";
+
+export interface HOTPOpts {
+    digits: number;
+    hash: "SHA-1" | "SHA-256";
+}
+
+export interface TOTPOpts extends HOTPOpts {
+    interval: number;
+}
+
+function getToken(hmac: Uint8Array, digits: number = 6): string {
+    const offset = hmac[hmac.length - 1] & 0xf;
+    const bin = new Uint8Array([hmac[offset] & 0x7f, hmac[offset + 1], hmac[offset + 2], hmac[offset + 3]]);
+    const num = bytesToNum(bin);
+    return (num % 10 ** digits).toString().padStart(digits, "0");
+}
+
+export async function hotp(
+    secret: Uint8Array,
+    counter: number,
+    { hash, digits }: HOTPOpts = { digits: 6, hash: "SHA-1" }
+) {
+    const hmac = await getProvider().sign(
+        secret,
+        numToBytes(counter),
+        new HMACParams({ hash, keySize: secret.length * 8 })
+    );
+    return getToken(hmac, digits);
+}
+
+export async function totp(
+    secret: Uint8Array,
+    time: number = Date.now(),
+    { interval, ...opts }: TOTPOpts = { interval: 30, digits: 6, hash: "SHA-1" }
+) {
+    const counter = Math.floor(time / interval / 1000);
+    return hotp(secret, counter, opts);
+}
+
+export function parseURL(data: string) {
+    const url = new URL(data);
+    const params = new URLSearchParams(url.search);
+    const secret = params.get("secret");
+
+    if (!secret || !base32ToBytes(secret).length) {
+        throw "Invalid secret";
+    }
+
+    return { secret };
+}