Invalid IV length with AES-192

Question

I'm updating my old function to encrypt password since createCipher is deprecated.

Here are my old functions:

  encrypt(payload) {
    let AES192 = crypto.createCipher('aes192', Buffer.from(config.secret))
    let crypted = AES192.update(payload, 'utf8', 'hex')
    crypted += AES192.final('hex')
    return crypted
  },

  decrypt(payload) {
    let AES192 = crypto.createDecipher('aes192', Buffer.from(config.secret))
    let decrypted = AES192.update(payload, 'hex', 'utf8')
    decrypted += AES192.final('utf8')
    return decrypted
  }

Here is what I tried to do:

  encrypt(payload) {
    const iv = crypto.randomBytes(96)
    const cipher = crypto.createCipheriv('aes192', Buffer.from(config.secret, 'hex'), iv)
    const encrypted = cipher.update(payload)
    encrypted = Buffer.concat([encrypted, cipher.final()])
    return iv.toString('hex') + ':' + encrypted.toString('hex')
  },

  decrypt(payload) {
    let textParts = payload.split(':')
    let iv = Buffer.from(textParts.shift(), 'hex')
    let encryptedText = Buffer.from(textParts.join(':'), 'hex')
    let decipher = crypto.createDecipheriv('aes192', Buffer.from(config.secret, 'hex'), iv)
    let decrypted = decipher.update(encryptedText)
    decrypted = Buffer.concat([decrypted, decipher.final()])
    return decrypted.toString()
  }

But I got this error when I try to do it:

Error: Invalid IV length
    at Cipheriv.createCipherBase (internal/crypto/cipher.js:103:19)
    at Cipheriv.createCipherWithIV (internal/crypto/cipher.js:121:20)
    at new Cipheriv (internal/crypto/cipher.js:225:22)
    at Object.createCipheriv (crypto.js:119:10)

For this line I tried multiple values like 12, 16, 32, 124 etc. But none are working

const iv = crypto.randomBytes(96)

user_7237224 · Answer

AES-192 (and for that matter AES-128 and AES-256) all use a 128 bit block length, so the IV should also be 128 bits, or 16 bytes. It's weird that you tried 16 as the length; at any rate this code is working for me:

function encrypt(payload) {
    const iv = crypto.randomBytes(16);
    const cipher = crypto.createCipheriv('aes192', Buffer.from(config.secret, 'hex'), iv)
    let encrypted = cipher.update(payload)
    encrypted = Buffer.concat([encrypted, cipher.final()])
    return iv.toString('hex') + ':' + encrypted.toString('hex')
}

I'm assuming config looks like this:

{ secret: 'dc8a453e728fc19398178797e2c39067e1965f2061220257' }

Invalid IV length with AES-192

1 Answers