totp-generator-lib

A TypeScript library for generating and validating Time-based One-Time Passwords (TOTP).

Installation

You can install the library via npm:

npm install totp-generator-lib

or

yarn add totp-generator-lib

Usage

Importing

import {
  generateOtp,
  generateBase32Secret,
  generateAuthURL,
  validateOtp,
} from 'totp-generator-lib';

Generating Base32 Secret

const secret = generateBase32Secret();
// S5OE62B7OKL5DCKKZGZA

You can pass custom length to generate secrent (default is 20 characters)

const secret = generateBase32Secret(25);
// S5OE62B7OKL5DCKKZGZAXIYWA

Generating Auth URL

const url = generateAuthURL({
  accountName: 'Example:[email protected]',
  issuer: 'Example',
  secret: secret,
});

This will generate an URL in a format, which can be read by authentication apps like Google Authenticator, Authy etc. Convert this text into QR code on client side using any library of your choice. Authentications apps will complete the setup process automatically once you scan that QR code.

Example auth URL:

otpauth://totp/Example:Example%3Ajohn_doe%40example.com?accountName=Example%3Ajohn_doe%40example.com&issuer=Example&secret=C7WDQWTH54HDHXMZYUUU7ZXIYWALBTS5

Optional parameters

• algorithm: The hashing algorithm to use (default is "SHA-1").
• digits: The number of digits in the generated TOTP (default is 6).
• period: The time period in seconds for which the TOTP is valid (default is 30 seconds).

const url = generateAuthURL({
  accountName: 'Example:[email protected]',
  issuer: 'Example',
  secret: secret,
  algorithm: 'SHA1',
  digits: 6,
  period: 30,
});

otpauth://totp/Example:Example%3Ajohn_doe%40example.com?accountName=Example%3Ajohn_doe%40example.com&issuer=Example&secret=C7WDQWTH54HDHXMZYUUU7ZXIYWALBTS5&algorithm=SHA1&digits=6&period=30

Generating TOTP

const otp = generateOtp(secret);
// 456785

Options

• algorithm: The hashing algorithm to use (default is "SHA-1").
• digits: The number of digits in the generated TOTP (default is 6).
• period: The time period in seconds for which the TOTP is valid (default is 30 seconds).
• timestamp: The UNIX timestamp in milliseconds to use as the reference time for TOTP generation (default is the current time).

const otp = generateOtp(secret, {
    algorithm: 'SHA-1',
    digits: 5,
    period: 30,
    timestamp: 1713354746707
});
// 34567

Validating TOTP

const isValid = validateOtp(otp, secret);
// false

Options

• algorithm: The hashing algorithm to use (default is "SHA-1").
• digits: The number of digits in the generated TOTP (default is 6).
• period: The time period in seconds for which the TOTP is valid (default is 30 seconds).
• window: The number of time steps before and after the current time step to check for valid OTPs during validation (default is 0).

const isValid = validateOtp(34567, secret, {
    algorithm: 'SHA-1',
    digits: 5,
    period: 30,
    window: 1
});
// true

License

This project is licensed under the MIT License - see the LICENSE file for details.

This README provides instructions on installing the library, its usage, API documentation, examples, and licensing information.