@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