PackedAES

Simple AES encryption/decryption file

Usage

For easy access to the single file, please go here.

You can use the code as follows.

do {
    let cryptor = try! AES(key: "0123456789ABCDEF")
    let iv      = Data("0123456789ABCDEF".utf8)
    
    let cipherText  = try cryptor.encrypt(Data("blocksizemessage".utf8), iv: iv)
    let plainText   = try cryptor.decrypt(cipherText, iv: iv)
    
    print(String(data: plainText, encoding: .utf8) ?? "Decryption failed, non UTF8 data returned")
} catch {
    print(error)
}

Block sizes

This AES operation works based on the AES block size. If your message is not a multiple of a block size, the crypto operation will fail. To prevent this from happening, use PKCS#7 padding, which is included in the options.

// "message" converted to data is not exactly a block size, padding is required
try cryptor.encrypt(Data("message".utf8), iv: iv, options: .pkcs7Padding)

IV

Note that it is very important that hte IV and key combination, should be unique for every crypto operation. It is highly recommended you generate a random key or random IV each time you perform a crypto operation.

Explanation and quotes taken from here:

The IV should be random and unpredictable, or at least unique for each message encrypted with a given key. [...] The IV never needs to be kept secret - if it did, it would be a key

However, if you use a random key each time, it's fine to use an all zero IV, which is included via AES.nullIV.

try cryptor.encrypt(plainText, iv: AES.nullIV, options: .pkcs7Padding)

One liners

There are also one liners to quickly encrypt and decrypt. Some of these one liners also have an implementation on the Data type and String type through an extension.

One liners

try AES.encrypt("message", key: key, iv: iv, options: .pkcs7Padding)

try AES.decrypt(cipherText, key: key, iv: iv, options: .pkcs7Padding)

Extensions

String example

let key = Data(repeating: 0, count: 16)
let iv  = Data(repeating: 6, count: 16)

try "message".encrypt(key: key, iv: iv, options: .pkcs7Padding)

Data example

let key = Data(repeating: 0, count: 16)
let iv  = Data(repeating: 8, count: 16)

try Data(repeating: 9, count: 8).encrypt(key: key, iv: iv, options: .pkcs7Padding)