Encrypt/Decrypt string in iOS using CryptoSwift

Question

I'm trying to encrypt a string and then decrypt it back using CryptoSwift. Here's the code:

    let key: [UInt8] = [0x2b,0x7e,0x15,0x16,0x28,0xae,0xd2,0xa6,0xab,0xf7,0x15,0x88,0x09,0xcf,0x4f,0x3c]
    let iv: [UInt8] = [0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F]

    let message = "Hello there!".dataUsingEncoding(NSUTF8StringEncoding)!.arrayOfBytes()
    do {
        let encryptedBytes = try ChaCha20(key: key, iv: iv)!.encrypt(message)
        let decryptedBytes = try ChaCha20(key: key, iv: iv)!.decrypt(encryptedBytes)
        let data = NSData.withBytes(decryptedBytes)
        let decrypted = String(data: data, encoding: NSUTF8StringEncoding)

        print(decrypted) // this should print "Hello there!", but it doesn't
    }
    catch { ... }

I think this should print out "Hello there!", the original string. But instead I get this: (<48656c6c 6f207468 65726521>, 4)

Any ideas what am I doing wrong?

Answer 1

I figured this out. Changed this line:

let decrypted = String(data: data, encoding: NSUTF8StringEncoding)

to:

let decrypted = String(bytes: decryptedBytes, encoding: NSUTF8StringEncoding)

and it's working now.