AshiTEAM AES

A helper class for my use to encrypt/decrypt binary data and string data and files using a password.

Installing

Install using npm

npm i @ashiteam/ashi-aes-node --save

The password to use for encryption/decryption can be passed in the constructor or as an optional parameter to the encrypt/decrypt functions.

To use, first import, create a variable and use as follows

import { AshiAesNode } from '@ashiteam/ashi-aes-node';

const aes = new AshiAesNode('my password');
const data =
'This is a test string to encrypt. This is a test string to encrypt. This is a test string to encrypt. This is a test string to encrypt';
const encData = aes.encryptString(data);
const decData = aes.decryptString(encData);

console.log(encData);
console.log(data);
console.log(decData);
console.log(decData == data ? 'All good' : 'ERROR');

To encrypt binarry data, use the encryptData & decryptData functions. You can pass in a Buffer and get back a Buffer to and from these functions.

const encBinaryData = aes.encryptData(binaryData);
const decBinaryData = aes.decryptData(encBinaryData);

To pass the password to the functions, do as follows

import { AshiAesNode } from '@ashiteam/ashi-aes';

const aes = new AshiAesNode('');

const encData = aes.encryptString(data, 'password to use');
const decData = aes.decryptString(encData, 'password to use');

To encrypt/decrypt files, do as follows

import { AshiAesNode } from '@ashiteam/ashi-aes';

const aes = new AshiAesNode('password to use');

const enc = aes.encryptFile(inFilePath, outFilePath);
await enc; // or use .then
const dec = aes.decryptFile(inFilePath, outFilePath);
await dec; // or use .then

Some Implementation Details

The key used for encryption/decryption is a 256 bit key generated using pbkdf2 using a random salt of 16 bytes long using 100 iterations. The 100 iterations is the default, this however can be changed to a different value by setting the iterations property.

When encrypting:

• The random salt is stored as the firs 16 bytes of the output.
• A randome iv of 16 bytes is generated and used and stored as the second 16 bytes of the output.
• The encrypted data is stored starting from the 32nd byte

When decrypting:

• The salt from the first 16 bytes are used to generate the key
• The second 16 bytes are used as the initial vector (iv)

Note

Data encrypted using other tools or languages (such as Java, C#, ...) can be decrypted by this code (and vice versa) provided the salt & iv are stored as the first 32 bytes, and the key is generated as mentiond above.

Authors

• Asanga Weerapura - All work

License

This project is licensed under the MIT License.

Acknowledgments

• node-forge
• buffer
• @ashiteam/ashi-aes