@open-charging-cloud/totp

TOTP is a TypeScript library for creating Time-based One-Time Passwords (TOTPs).

https://www.npmjs.com/package/@open-charging-cloud/totp

It can be used e.g. for Secure Dynamic QR-Codes in E-Mobility or a secure alternative for legacy HTTP BASIC Authentication mechanisms using Authorization: TOTP <token> <totp>.

Installation

npm install @open-charging-cloud/totp

Usage

import { generateTOTPs } from "@open-charging-cloud/totp";

const totps = generateTOTPs("secure!Charging!");

console.log(totps.current);
console.log(totps.remainingTime);

You can also pass an options object:

const totps = generateTOTPs({
  sharedSecret:  "secure!Charging!",
  validityTime:   30,
  totpLength:     12,
  alphabet:      "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ",
  timestamp:      Date.now(),
  hashAlgorithm: "sha256"
});

API

generateTOTPs(sharedSecret, validityTime, totpLength, alphabet, timestamp, hashAlgorithm)

Generates TOTP values for the previous, current, and next time slot.

Parameters:

| Parameter | Description | Default | | --- | --- | --- | | sharedSecret | Shared secret string, at least 16 characters, without whitespace. | Required | | validityTime | Slot duration in seconds. | 30 | | totpLength | Generated token length. | 12 | | alphabet | Alphabet used for token characters. | Digits, lowercase letters, and uppercase letters | | timestamp | Unix timestamp in milliseconds or Date. | Date.now() | | hashAlgorithm | HMAC hash algorithm. Must be sha256, sha384, or sha512. | sha256 |

Returns:

{
  previous:       string;
  current:        string;
  next:           string;
  remainingTime:  number;
}

Development

npm install
npm test