Symmetric File encryption in node js (AES-192)

how everybody. today I'm gonna show you how to encrypt a file using a symmetric encryption algorithm such as AES in node js.

first of all, we need to import the fs module to make us able to work with files:

const fs = require('fs')

and also some methods from the crypto module:

const {scryptSync, createDecipheriv, createCipheriv} = require('crypto')

now it's the time to create encrypt function that take required arguments and encrypt

const encrypt = (filePath, output, algorithm, key, iv)=> {
    const fileStream = fs.ReadStream(filePath)
    const outputFileStream = fs.createWriteStream(output)

    const cipher = createCipheriv(algorithm, key, iv)
    let encrypted

    fileStream.on('data', (data)=>{
        encrypted = cipher.update(data)
        outputFileStream.write(encrypted)
    })

    fileStream.on('end', ()=>{
        outputFileStream.end()
    })

}

and also the decrypt function to decrypt the encrypted file:

const decrypt = (inputFilePath, outputFilePath, algorithm,key, iv)=> {
    const outputWriteSteam = fs.createWriteStream(outputFilePath)
    const inputReadStream = fs.ReadStream(inputFilePath)

    const decipher = createDecipheriv(algorithm,key, iv)
    let decrypted
    inputReadStream.on('data', (data)=>{
        decrypted = decipher.update(data)
        outputWriteSteam.write(decrypted)
    })

    inputReadStream.on('end', ()=>{
        outputWriteSteam.end()
    })

}

new before calling encrypt or decrypt function we need to determine password, algorithm, key and iv:

const password= '0000'
const algorithm = 'aes-192-cbc' // can be replaced with other algorithms
let key = scryptSync(password, 'salt',24)
let iv = Buffer.alloc(16,0)

now we just need to call encrypt or decrypt function

encrypt('./f.mp3', 'enc.enc', algorithm, key, iv) // to ecnrypt
decrypt('enc.enc', './f.mp3', algorithm, key, iv) // to decrypt