Could the IV be automatically extracted from the encrypted data?

[backslash-f]

More like a question.

So this works fine:

let data = "The black knight always triumphs!".convertToData()
let key = "01234567890123456789012345678901".convertToData()
let iv = try CryptoRandom().generateData(count: 16)
let encryptedData = try AES256CBC.encrypt(data, key: key, iv: iv)

let decryptedData = try AES256CBC.decrypt(encryptedData, key: key, iv: iv)
print(decryptedData.convert(to: String.self)) // The black knight always triumphs!

Question is can I not pass in the iv as argument so it could be automatically extracted from the encrypted data? As in:

let decryptedData = try AES256CBC.decrypt(encryptedData, key: key) <<--
print(decryptedData.convert(to: String.self))

Throws: ⚠️ [CryptoError.cipherIVSize: Invalid cipher IV length 0 != 16.]

I'm trying to avoid having to pass the IV around as in here (relies on Apple's CommonCryto / CCCryptor).

Thanks.

[vzsg]

No, but if you want, you could prepend the IV to the ciphertext, send/store them together, then split off the first 16 bytes when decrypting. After checking your library, you seem to be doing the same thing implicitly.

Well, with vapor/crypto, you'll have to do it explicitly :)

[backslash-f]

you seem to be doing the same thing implicitly <<-- exactly 🙃
(also this)

All right, then. Thanks for confirming. 👍🏻