@bytekit/totp

A lightweight, promise-based library for generating TOTP and HOTP tokens in Node.js and browser environments. Fully supports standard OTP URI parsing and flexible configuration options.

Features

• 🔐 Generate Time-based One-Time Passwords (TOTP)
• 🔢 Generate HMAC-based One-Time Passwords (HOTP)
• 🌐 Parse and extract OTP configuration from standard otpauth:// URIs
• 📦 Lightweight and dependency-free

Installation

npm install @bytekit/totp

or

yarn add @bytekit/totp

Usage

Generate a TOTP

import { totp } from "@bytekit/totp";

const token = await totp({
  key: "JBSWY3DPEHPK3PXP", // base32 or Uint8Array
  digits: 6,              // optional, default: 6
  algorithm: "SHA-1",     // optional, default: SHA-1
  period: 30,             // optional, default: 30
  timestamp: Date.now() / 1000,  // optional, default: now (seconds)
});

console.log(token.token); // => "123456"
console.log(token.expires);   // Timestamp when this token expires
console.log(token.next);      // Next valid token
console.log(token.previous);  // Previous valid token

Generate a HOTP

import { hotp } from "@bytekit/totp";

const key = new Uint8Array([/* your binary secret key */]);
const counter = new Uint8Array([/* your counter as binary */]);

const token = await hotp(key, counter, 6, "SHA-1");

console.log(token); // => "654321"

Parse an OTP URI

import { parseOtpUri } from "@bytekit/totp";

const otpAuth = parseOtpUri("otpauth://totp/Example:[email protected]?secret=JBSWY3DPEHPK3PXP&issuer=Example");

console.log(otpAuth);
/*
{
  type: 'totp',
  account: '[email protected]',
  issuer: 'Example',
  key: 'JBSWY3DPEHPK3PXP',
  digits: 6,
  algorithm: 'SHA-1',
  period: 30
}
*/

Types

ITotpOptions

| Option | Type | Default | Description | |------------|--------------------|----------|-----------------------------------------------------| | key | string or Uint8Array | — | Secret key in base32 or binary | | digits | number | 6 | Number of digits in the OTP | | algorithm| string | "SHA-1"| Hashing algorithm (SHA-1, SHA-256, etc.) | | period | number | 30 | Validity period in seconds | | timestamp| number | now | Unix timestamp to calculate OTP for |

ITotpToken

interface ITotpToken {
  token: string;
  expires: number;
  next: string;
  previous: string;
}

IOtpAuth

Returned by parseOtpUri.

interface IOtpAuth {
  type: string;
  account: string;
  issuer?: string;
  key: string | Uint8Array;
  digits?: number;
  algorithm?: string;
  period?: number;
  counter?: number;
}

License

MIT