Node-buffer-crypto NPM

Node Crypto Buffer

NPM package to Encrypt data of unlimited size with any public/private encryption key of a known mod-length.

crypto is amazing package for encrypting and decrypting your data, but encrypting Public/Private keys has its hassles.

Usage

const { decryptBigBuffer, encryptBigBuffer } = require("node-buffer-crypto")
const { publicKey, privateKey } = require("./keypair.json")
const MOD_LENGTH = 64

const sample = Buffer.from("Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.")

// encrypt data with public key
const enc = encryptBigBuffer(publicKey, MOD_LENGTH, sample)

// decrypt data with private key
const dec = decryptBigBuffer(privateKey, enc)

How `crypto` works with Public-Private key pair? (For Crypto Noobies)

Don't take Noobies as offensive, I just don't want to be absurd while giving some very basic docs

Public Key and Private Key

Public key is used to encrypt a given data and can be shared with anyone who needs to encrypt the data. {data} ---> encryptor(publicKey, {data}) ---> encryptedBuffer<xyz...>

Private key is used to decrypt a the data encrypted with its Public key pair. encryptedBuffer<xyz...> ---> decryptor(privateKey, encryptedBuffer)--->{data}

The data once encrypted with Public key can not be decrypted back without the Private key. Not even with the public key itself.

Creating a Public Private key pair

We will use openssl

Make one private key into a file named enc.key

openssl genrsa -out enc.key 1028

1028 is padding, which means our mod length will be approximate 90, we may consider our mod length as 64 to keep our code fail-safe.

Make one public key from the new private key into a file named enc.pub

openssl rsa -in enc.key -out enc.pub -pubout -outform PEM

Using Node JS `crypto`

example: noob1

const { publicEncrypt, privateDecrypt } = require("crypto")
const { readFileSync } = require("fs")
const { strictEqual } = require("assert")

const publicKey = readFileSync("./enc.pub")
const privateKey = readFileSync("./enc.pub")

const sampleData = Buffer.from("Sample to encrypt")

const encryptedData = publicEncrypt(publicKey, sampleData)

const decryptedData = privateDecrypt(privateKey, encryptedData)

strictEqual(decryptedData, sampleData)