node-dukpt

Derived Unique Key Per Transaction (DUKPT) Encryption with NodeJS

This the NodeJS implementation of DUKPT based on the vanilla javascript implementation of IDTech DUKPT encryption/decryption. This module provides Dukpt encryption using either 3DES or AES schemes.

Please note that AES encryption/decryption is currently only supported with NodeJS versions 6.x.x and above due to few limitations which will be addressed soon in a next release.

Don't hesitate to report any bugs in the Github Repository!. Many thanks to @jamiesoncj for providing resources.

Prerequisites

• Node v12.0.0 or above

Installing

npm install dukpt --save

Using DUKPT

Initialize DUKPT by providing BDK and KSN:

const Dukpt = require('dukpt');

const encryptionBDK = '0123456789ABCDEFFEDCBA9876543210';
const ksn = 'FFFF9876543210E00008';
const keyMode = 'datakey'; // optional: defaults to 'datakey'
const plainTextCardData = '%B5452310551227189^DOE/JOHN      ^08043210000000725000000?';

const dukpt = new Dukpt(encryptionBDK, ksn);

After initializing, you can use dukptEncrypt and dukptDecrypt methods to encrypt/decrypt data using DUKPT.

Encrypting ascii data

Using 3DES,

const options = {
	inputEncoding: 'ascii', 
	outputEncoding: 'hex',
	encryptionMode: '3DES'
};
const encryptedCardData3Des = dukpt.dukptEncrypt(plainTextCardData, options);

or with AES,

const options = {
	inputEncoding: 'ascii', 
	outputEncoding: 'hex',
	encryptionMode: 'AES'
};
const encryptedCardDataAes = dukpt.dukptEncrypt(plainTextCardData, options);

Encrypting hex data

Using 3DES,

const options = {
	inputEncoding: 'hex',
	outputEncoding: 'hex',
	encryptionMode: '3DES'
};
const encryptedCardData3Des = dukpt.dukptEncrypt(plainTextCardData, options);

or using AES,

const options = {
	inputEncoding: 'hex',
	outputEncoding: 'hex',
	encryptionMode: 'AES'
};
const encryptedCardDataAes = dukpt.dukptEncrypt(plainTextCardData, options);

Decrypting data with ascii output encoding

const options = {
	outputEncoding: 'ascii',
	decryptionMode: '3DES',
	trimOutput: true
};

const decryptedCardData = dukpt.dukptDecrypt(encryptedCardData, options);

Decrypting data with hex output encoding

const options = {
	outputEncoding: 'hex',
	decryptionMode: '3DES',
	trimOutput: true
};

const decryptedCardData = dukpt.dukptDecrypt(encryptedCardData, options);

API

constructor Dukpt(bdk, ksn, [keyMode])

bdk

Base derivation key (BDK) for initialization

ksn

Key serial number (KSN) for initialization

See here for more information on BDK and KSN

keyMode

default: 'datakey'

Key mode for deriving session key from initial pin encryption key (IPEK). Possible values are:

• datakey (default)
• pinkey
• mackey

Dukpt.prototype.dukptEncrypt(plainTextCardData, options) and Dukpt.prototype.dukptDecrypt(encryptedCardData, options)

options

You can use options object to provide additional options for the DUKPT encryption/decryption. This object is optional and, if you don't provide it, encryption/decryption will use the default values shipped with it.

Following listed are the available options.

Option	Possible Values	Default Value	Description
outputEncoding	ascii, hex	For encryption hex, for decryption ascii	Specify output encoding of encryption/decryption
inputEncoding	ascii, hex	For encryption ascii, for decryption hex	Specify encoding of the input data for encryption/decryption
trimOutput (for decryption only)	true, false	false	Specify whether to strip out null characters from the decrypted output
encryptionMode (for encryption only)	3DES/AES	3DES/AES	Specify encryption scheme for dukpt
decryptionMode (for decryption only)	3DES/AES	3DES/AES	Specify decryption scheme for dukpt

Tests

Tests can be run using gulp as follows:

npm run test

Roadmap

• Support for DUKPT Encryption/Decryption with 3DES
• Support for DUKPT Encryption/Decryption with AES