ios - Cifrado AES en Swift

cryptography commoncrypto

Question

Estoy tratando de implementar el cifrado AES de forma rápida. El descifrado de cifrado para Android y C # funciona correctamente. Necesito implementarlo rápidamente. Es el código actual para Android y C # es seguido por esto.

Traté de usar

1. CryptoSwift
2. Cifrado AES multiplataforma

Pero nada de eso funciona. Cuando envío la cadena cifrada en el servidor, no se ha descifrado.

Cualquier ayuda será apreciada

Answer 1

Asegúrese de usar los mismos parámetros que parecen ser AES con el modo CBC con iv, PKCS5Padding (en realidad PKCS # 7) y una clave de 16 bytes (128 bits).

El relleno PKCS # 5 y el relleno PKCS#7 son esencialmente iguales, a veces por razones históricas El relleno PKCS # 5 se especifica para usar con AES pero el relleno real es PKCS # 7.

Asegúrese de que las codificaciones de la clave, iv y los datos cifrados coincidan. Hex los descarga en ambas plataformas para garantizar que sean idénticos. Las funciones de cifrado no son difíciles de usar, si todos los parámetros de entrada son correctos, la salida será correcta.

Para hacer esto más seguro, el iv debe ser bytes aleatorios y antepuestos a los datos cifrados para su uso durante el descifrado.

El cifrado AES de plataforma cruzada utiliza una clave de 256 bits, por lo que no funcionará tal cual.

Ejemplo:

Swift 2

// operation: kCCEncrypt or kCCDecrypt
func testCrypt(data data:[UInt8], keyData:[UInt8], ivData:[UInt8], operation:Int) -> [UInt8]? {
    let cryptLength  = size_t(data.count+kCCBlockSizeAES128)
    var cryptData    = [UInt8](count:cryptLength, repeatedValue:0)

    let keyLength             = size_t(kCCKeySizeAES128)
    let algoritm: CCAlgorithm = UInt32(kCCAlgorithmAES128)
    let options:  CCOptions   = UInt32(kCCOptionPKCS7Padding)

    var numBytesEncrypted :size_t = 0

    let cryptStatus = CCCrypt(CCOperation(operation),
                              algoritm,
                              options,
                              keyData, keyLength,
                              ivData,
                              data, data.count,
                              &cryptData, cryptLength,
                              &numBytesEncrypted)

    if UInt32(cryptStatus) == UInt32(kCCSuccess) {
        cryptData.removeRange(numBytesEncrypted..<cryptData.count)

    } else {
        print("Error: /(cryptStatus)")
    }

    return cryptData;
}

let message       = "Don´t try to read this text. Top Secret Stuff"
let messageData   = Array(message.utf8)
let keyData       = Array("12345678901234567890123456789012".utf8)
let ivData        = Array("abcdefghijklmnop".utf8)
let encryptedData = testCrypt(data:messageData,   keyData:keyData, ivData:ivData, operation:kCCEncrypt)!
let decryptedData = testCrypt(data:encryptedData, keyData:keyData, ivData:ivData, operation:kCCDecrypt)!
var decrypted     = String(bytes:decryptedData, encoding:NSUTF8StringEncoding)!

print("message:       /(message)");
print("messageData:   /(NSData(bytes:messageData,   length:messageData.count))");
print("keyData:       /(NSData(bytes:keyData,       length:keyData.count))");
print("ivData:        /(NSData(bytes:ivData,        length:ivData.count))");
print("encryptedData: /(NSData(bytes:encryptedData, length:encryptedData.count))");
print("decryptedData: /(NSData(bytes:decryptedData, length:decryptedData.count))");
print("decrypted:     /(String(bytes:decryptedData,encoding:NSUTF8StringEncoding)!)");

Salida:

message: Don´t try to read this text. Top Secret Stuff messageData: 446f6ec2 b4742074 72792074 6f207265 61642074 68697320 74657874 2e20546f 70205365 63726574 20537475 6666 keyData: 31323334 35363738 39303132 33343536 37383930 31323334 35363738 39303132 ivData: 61626364 65666768 696a6b6c 6d6e6f70 encryptedData: b1b6dc17 62eaf3f8 baa1cb87 21ddc35c dee803ed fb320020 85794848 21206943 a85feb5b c8ee58fc d6fb664b 96b81114 decryptedData: 446f6ec2 b4742074 72792074 6f207265 61642074 68697320 74657874 2e20546f 70205365 63726574 20537475 6666 decrypted: Don´t try to read this text. Top Secret Stuff

Swift 3 con tipo [UInt8]

func testCrypt(data:[UInt8], keyData:[UInt8], ivData:[UInt8], operation:Int) -> [UInt8]? {
    let cryptLength  = size_t(data.count+kCCBlockSizeAES128)
    var cryptData    = [UInt8](repeating:0, count:cryptLength)

    let keyLength             = size_t(kCCKeySizeAES128)
    let algoritm: CCAlgorithm = UInt32(kCCAlgorithmAES128)
    let options:  CCOptions   = UInt32(kCCOptionPKCS7Padding)

    var numBytesEncrypted :size_t = 0

    let cryptStatus = CCCrypt(CCOperation(operation),
                              algoritm,
                              options,
                              keyData, keyLength,
                              ivData,
                              data, data.count,
                              &cryptData, cryptLength,
                              &numBytesEncrypted)

    if UInt32(cryptStatus) == UInt32(kCCSuccess) {
        cryptData.removeSubrange(numBytesEncrypted..<cryptData.count)

    } else {
        print("Error: /(cryptStatus)")
    }

    return cryptData;
}

Swift 3 y 4 con tipo de Data

func testCrypt(data:Data, keyData:Data, ivData:Data, operation:Int) -> Data {
    let cryptLength  = size_t(data.count + kCCBlockSizeAES128)
    var cryptData = Data(count:cryptLength)

    let keyLength             = size_t(kCCKeySizeAES128)
    let options   = CCOptions(kCCOptionPKCS7Padding)


    var numBytesEncrypted :size_t = 0

    let cryptStatus = cryptData.withUnsafeMutableBytes {cryptBytes in
        data.withUnsafeBytes {dataBytes in
            ivData.withUnsafeBytes {ivBytes in
                keyData.withUnsafeBytes {keyBytes in
                    CCCrypt(CCOperation(operation),
                              CCAlgorithm(kCCAlgorithmAES),
                              options,
                              keyBytes, keyLength,
                              ivBytes,
                              dataBytes, data.count,
                              cryptBytes, cryptLength,
                              &numBytesEncrypted)
                }
            }
        }
    }

    if UInt32(cryptStatus) == UInt32(kCCSuccess) {
        cryptData.removeSubrange(numBytesEncrypted..<cryptData.count)

    } else {
        print("Error: /(cryptStatus)")
    }

    return cryptData;
}

let message     = "Don´t try to read this text. Top Secret Stuff"
let messageData = message.data(using:String.Encoding.utf8)!
let keyData     = "12345678901234567890123456789012".data(using:String.Encoding.utf8)!
let ivData      = "abcdefghijklmnop".data(using:String.Encoding.utf8)!

let encryptedData = testCrypt(data:messageData,   keyData:keyData, ivData:ivData, operation:kCCEncrypt)
let decryptedData = testCrypt(data:encryptedData, keyData:keyData, ivData:ivData, operation:kCCDecrypt)
var decrypted     = String(bytes:decryptedData, encoding:String.Encoding.utf8)!

Ejemplo de la sección de documentación expirada:

Cifrado AES en modo CBC con un IV aleatorio (Swift 3+)

El iv está prefijado a los datos encriptados

aesCBC128Encrypt creará un IV aleatorio y con el prefijo del código cifrado.
aesCBC128Decrypt usará el IV prefijado durante el descifrado.

Las entradas son los datos y la clave son objetos de datos. Si es una forma codificada como Base64 si es necesario, convierta ay desde el método de llamada.

La clave debe tener exactamente 128 bits (16 bytes), 192 bits (24 bytes) o 256 bits (32 bytes) de longitud. Si se utiliza otro tamaño de clave, se generará un error.

PKCS#7 está configurado de forma predeterminada.

Este ejemplo requiere criptografía común
Es necesario tener un encabezado de puente para el proyecto:
#import <CommonCrypto/CommonCrypto.h>
Agregue Security.framework al proyecto.

Este es un ejemplo, no un código de producción.

enum AESError: Error {
    case KeyError((String, Int))
    case IVError((String, Int))
    case CryptorError((String, Int))
}

// The iv is prefixed to the encrypted data
func aesCBCEncrypt(data:Data, keyData:Data) throws -> Data {
    let keyLength = keyData.count
    let validKeyLengths = [kCCKeySizeAES128, kCCKeySizeAES192, kCCKeySizeAES256]
    if (validKeyLengths.contains(keyLength) == false) {
        throw AESError.KeyError(("Invalid key length", keyLength))
    }

    let ivSize = kCCBlockSizeAES128;
    let cryptLength = size_t(ivSize + data.count + kCCBlockSizeAES128)
    var cryptData = Data(count:cryptLength)

    let status = cryptData.withUnsafeMutableBytes {ivBytes in
        SecRandomCopyBytes(kSecRandomDefault, kCCBlockSizeAES128, ivBytes)
    }
    if (status != 0) {
        throw AESError.IVError(("IV generation failed", Int(status)))
    }

    var numBytesEncrypted :size_t = 0
    let options   = CCOptions(kCCOptionPKCS7Padding)

    let cryptStatus = cryptData.withUnsafeMutableBytes {cryptBytes in
        data.withUnsafeBytes {dataBytes in
            keyData.withUnsafeBytes {keyBytes in
                CCCrypt(CCOperation(kCCEncrypt),
                        CCAlgorithm(kCCAlgorithmAES),
                        options,
                        keyBytes, keyLength,
                        cryptBytes,
                        dataBytes, data.count,
                        cryptBytes+kCCBlockSizeAES128, cryptLength,
                        &numBytesEncrypted)
            }
        }
    }

    if UInt32(cryptStatus) == UInt32(kCCSuccess) {
        cryptData.count = numBytesEncrypted + ivSize
    }
    else {
        throw AESError.CryptorError(("Encryption failed", Int(cryptStatus)))
    }

    return cryptData;
}

// The iv is prefixed to the encrypted data
func aesCBCDecrypt(data:Data, keyData:Data) throws -> Data? {
    let keyLength = keyData.count
    let validKeyLengths = [kCCKeySizeAES128, kCCKeySizeAES192, kCCKeySizeAES256]
    if (validKeyLengths.contains(keyLength) == false) {
        throw AESError.KeyError(("Invalid key length", keyLength))
    }

    let ivSize = kCCBlockSizeAES128;
    let clearLength = size_t(data.count - ivSize)
    var clearData = Data(count:clearLength)

    var numBytesDecrypted :size_t = 0
    let options   = CCOptions(kCCOptionPKCS7Padding)

    let cryptStatus = clearData.withUnsafeMutableBytes {cryptBytes in
        data.withUnsafeBytes {dataBytes in
            keyData.withUnsafeBytes {keyBytes in
                CCCrypt(CCOperation(kCCDecrypt),
                        CCAlgorithm(kCCAlgorithmAES128),
                        options,
                        keyBytes, keyLength,
                        dataBytes,
                        dataBytes+kCCBlockSizeAES128, clearLength,
                        cryptBytes, clearLength,
                        &numBytesDecrypted)
            }
        }
    }

    if UInt32(cryptStatus) == UInt32(kCCSuccess) {
        clearData.count = numBytesDecrypted
    }
    else {
        throw AESError.CryptorError(("Decryption failed", Int(cryptStatus)))
    }

    return clearData;
}

Ejemplo de uso:

let clearData = "clearData0123456".data(using:String.Encoding.utf8)!
let keyData   = "keyData890123456".data(using:String.Encoding.utf8)!
print("clearData:   /(clearData as NSData)")
print("keyData:     /(keyData as NSData)")

var cryptData :Data?
do {
    cryptData = try aesCBCEncrypt(data:clearData, keyData:keyData)
    print("cryptData:   /(cryptData! as NSData)")
}
catch (let status) {
    print("Error aesCBCEncrypt: /(status)")
}

let decryptData :Data?
do {
    let decryptData = try aesCBCDecrypt(data:cryptData!, keyData:keyData)
    print("decryptData: /(decryptData! as NSData)")
}
catch (let status) {
    print("Error aesCBCDecrypt: /(status)")
}

Salida de ejemplo:

clearData:   <636c6561 72446174 61303132 33343536>
keyData:     <6b657944 61746138 39303132 33343536>
cryptData:   <92c57393 f454d959 5a4d158f 6e1cd3e7 77986ee9 b2970f49 2bafcf1a 8ee9d51a bde49c31 d7780256 71837a61 60fa4be0>
decryptData: <636c6561 72446174 61303132 33343536>

Notas:
Un problema típico con el código de ejemplo del modo CBC es que deja la creación y el uso compartido del IV aleatorio para el usuario. Este ejemplo incluye la generación del IV, prefija los datos cifrados y usa el IV prefijado durante el descifrado. Esto libera al usuario ocasional de los detalles necesarios para el modo CBC .

Por seguridad, los datos cifrados también deben tener autenticación, este código de ejemplo no proporciona eso para que sea pequeño y permita una mejor interoperabilidad para otras plataformas.

También falta la derivación de la clave de una contraseña, se sugiere que se use PBKDF2 contraseñas de texto se usan como material de claves.

Para obtener un código de cifrado multiplataforma listo para la producción sólida, consulte RNCryptor .

Answer 2

Basado en la gran respuesta de @zaph, creo este Playground para:

Swift 5

import Foundation
import CommonCrypto

protocol Cryptable {
    func encrypt(_ string: String) throws -> Data
    func decrypt(_ data: Data) throws -> String
}

struct AES {
    private let key: Data
    private let ivSize: Int         = kCCBlockSizeAES128
    private let options: CCOptions  = CCOptions(kCCOptionPKCS7Padding)

    init(keyString: String) throws {
        guard keyString.count == kCCKeySizeAES256 else {
            throw Error.invalidKeySize
        }
        self.key = Data(keyString.utf8)
    }
}

extension AES {
    enum Error: Swift.Error {
        case invalidKeySize
        case generateRandomIVFailed
        case encryptionFailed
        case decryptionFailed
        case dataToStringFailed
    }
}

private extension AES {

    func generateRandomIV(for data: inout Data) throws {

        try data.withUnsafeMutableBytes { dataBytes in

            guard let dataBytesBaseAddress = dataBytes.baseAddress else {
                throw Error.generateRandomIVFailed
            }

            let status: Int32 = SecRandomCopyBytes(
                kSecRandomDefault,
                kCCBlockSizeAES128,
                dataBytesBaseAddress
            )

            guard status == 0 else {
                throw Error.generateRandomIVFailed
            }
        }
    }
}

extension AES: Cryptable {

    func encrypt(_ string: String) throws -> Data {
        let dataToEncrypt = Data(string.utf8)

        let bufferSize: Int = ivSize + dataToEncrypt.count + kCCBlockSizeAES128
        var buffer = Data(count: bufferSize)
        try generateRandomIV(for: &buffer)

        var numberBytesEncrypted: Int = 0

        do {
            try key.withUnsafeBytes { keyBytes in
                try dataToEncrypt.withUnsafeBytes { dataToEncryptBytes in
                    try buffer.withUnsafeMutableBytes { bufferBytes in

                        guard let keyBytesBaseAddress = keyBytes.baseAddress,
                            let dataToEncryptBytesBaseAddress = dataToEncryptBytes.baseAddress,
                            let bufferBytesBaseAddress = bufferBytes.baseAddress else {
                                throw Error.encryptionFailed
                        }

                        let cryptStatus: CCCryptorStatus = CCCrypt( // Stateless, one-shot encrypt operation
                            CCOperation(kCCEncrypt),                // op: CCOperation
                            CCAlgorithm(kCCAlgorithmAES),           // alg: CCAlgorithm
                            options,                                // options: CCOptions
                            keyBytesBaseAddress,                    // key: the "password"
                            key.count,                              // keyLength: the "password" size
                            bufferBytesBaseAddress,                 // iv: Initialization Vector
                            dataToEncryptBytesBaseAddress,          // dataIn: Data to encrypt bytes
                            dataToEncryptBytes.count,               // dataInLength: Data to encrypt size
                            bufferBytesBaseAddress + ivSize,        // dataOut: encrypted Data buffer
                            bufferSize,                             // dataOutAvailable: encrypted Data buffer size
                            &numberBytesEncrypted                   // dataOutMoved: the number of bytes written
                        )

                        guard cryptStatus == CCCryptorStatus(kCCSuccess) else {
                            throw Error.encryptionFailed
                        }
                    }
                }
            }

        } catch {
            throw Error.encryptionFailed
        }

        let encryptedData: Data = buffer[..<(numberBytesEncrypted + ivSize)]
        return encryptedData
    }

    func decrypt(_ data: Data) throws -> String {

        let bufferSize: Int = data.count - ivSize
        var buffer = Data(count: bufferSize)

        var numberBytesDecrypted: Int = 0

        do {
            try key.withUnsafeBytes { keyBytes in
                try data.withUnsafeBytes { dataToDecryptBytes in
                    try buffer.withUnsafeMutableBytes { bufferBytes in

                        guard let keyBytesBaseAddress = keyBytes.baseAddress,
                            let dataToDecryptBytesBaseAddress = dataToDecryptBytes.baseAddress,
                            let bufferBytesBaseAddress = bufferBytes.baseAddress else {
                                throw Error.encryptionFailed
                        }

                        let cryptStatus: CCCryptorStatus = CCCrypt( // Stateless, one-shot encrypt operation
                            CCOperation(kCCDecrypt),                // op: CCOperation
                            CCAlgorithm(kCCAlgorithmAES128),        // alg: CCAlgorithm
                            options,                                // options: CCOptions
                            keyBytesBaseAddress,                    // key: the "password"
                            key.count,                              // keyLength: the "password" size
                            dataToDecryptBytesBaseAddress,          // iv: Initialization Vector
                            dataToDecryptBytesBaseAddress + ivSize, // dataIn: Data to decrypt bytes
                            bufferSize,                             // dataInLength: Data to decrypt size
                            bufferBytesBaseAddress,                 // dataOut: decrypted Data buffer
                            bufferSize,                             // dataOutAvailable: decrypted Data buffer size
                            &numberBytesDecrypted                   // dataOutMoved: the number of bytes written
                        )

                        guard cryptStatus == CCCryptorStatus(kCCSuccess) else {
                            throw Error.decryptionFailed
                        }
                    }
                }
            }
        } catch {
            throw Error.encryptionFailed
        }

        let decryptedData: Data = buffer[..<numberBytesDecrypted]

        guard let decryptedString = String(data: decryptedData, encoding: .utf8) else {
            throw Error.dataToStringFailed
        }

        return decryptedString
    }
}

do {
    let aes = try AES(keyString: "FiugQTgPNwCWUY,VhfmM4cKXTLVFvHFe")

    let stringToEncrypt: String = "please encrypt meeee"
    print("String to encrypt:/t/t/t/(stringToEncrypt)")

    let encryptedData: Data = try aes.encrypt(stringToEncrypt)
    print("String encrypted (base64):/t/(encryptedData.base64EncodedString())")

    let decryptedData: String = try aes.decrypt(encryptedData)
    print("String decrypted:/t/t/t/(decryptedData)")

} catch {
    print("Something went wrong: /(error)")
}

Salida:

También creé un paquete Swift basado en él:

https://github.com/backslash-f/aescryptable ✌🏻

Answer 3

Encontré una buena biblioteca llamada RNCryptor implementada en lenguaje rápido para el cifrado / descifrado AES.

La instalación se puede hacer con Cocoapods o Carthage. Aquí está el código de muestra para el cifrado y descifrado.

// Encryption
let data = "sample data string".data(using: String.Encoding.utf8)
let password = "Secret password"
let encryptedData = RNCryptor.encrypt(data: data, withPassword: password)

// Decryption
do {
    let originalData = try RNCryptor.decrypt(data: encryptedData, withPassword: password)
    // ...
} catch {
    print(error)
}

Answer 4

He usado CryptoSwift.

Primero tengo que instalar cryptoSwift en el archivo pod. Luego, en mi controlador de vista, importé CryptoSwift.

Aquí está el código que he usado:

let value = "xyzzy".  // This is the value that we want to encrypt
let key = "abc".      // This is the key 

let EncryptedValue = try! value.aesEncrypt(key: key)
let DecryptedValue = try! EncryptedValue.aesDecrypt(key: key)

Luego, usando la extensión String:

extension String {

    func aesEncrypt(key: String) throws -> String {

        var result = ""

        do {

            let key: [UInt8] = Array(key.utf8) as [UInt8]
            let aes = try! AES(key: key, blockMode: .ECB, padding: .pkcs5) // AES128 .ECB pkcs7
            let encrypted = try aes.encrypt(Array(self.utf8))

            result = encrypted.toBase64()!

            print("AES Encryption Result: /(result)")

        } catch {

            print("Error: /(error)")
        }

        return result
    }

    func aesDecrypt(key: String) throws -> String {

        var result = ""

        do {

            let encrypted = self
            let key: [UInt8] = Array(key.utf8) as [UInt8]
            let aes = try! AES(key: key, blockMode: .ECB, padding: .pkcs5) // AES128 .ECB pkcs7
            let decrypted = try aes.decrypt(Array(base64: encrypted))

            result = String(data: Data(decrypted), encoding: .utf8) ?? ""

            print("AES Decryption Result: /(result)")

        } catch {

            print("Error: /(error)")
        }

        return result
    }
}

¡En esto no he usado iv y encrypted.toBase64 () para cifrar como result = encrypted.toBase64()! en lugar del result = encrypted.toStringHex()! en encriptación

y similar en descifrado let decrypted = try aes.decrypt(Array(base64: encrypted)) en lugar de let decrypted = try aes.decrypt(Array(Hex: encrypted))

Answer 5

Mis dos centavos:

Extensión swift 4 / xcode 9 para datos:

extension Data{

    func aesEncrypt( keyData: Data, ivData: Data, operation: Int) -> Data {
        let dataLength = self.count
        let cryptLength  = size_t(dataLength + kCCBlockSizeAES128)
        var cryptData = Data(count:cryptLength)

        let keyLength = size_t(kCCKeySizeAES128)
        let options = CCOptions(kCCOptionPKCS7Padding)


        var numBytesEncrypted :size_t = 0

        let cryptStatus = cryptData.withUnsafeMutableBytes {cryptBytes in
            self.withUnsafeBytes {dataBytes in
                ivData.withUnsafeBytes {ivBytes in
                    keyData.withUnsafeBytes {keyBytes in
                        CCCrypt(CCOperation(operation),
                                CCAlgorithm(kCCAlgorithmAES),
                                options,
                                keyBytes, keyLength,
                                ivBytes,
                                dataBytes, dataLength,
                                cryptBytes, cryptLength,
                                &numBytesEncrypted)
                    }
                }
            }
        }

        if UInt32(cryptStatus) == UInt32(kCCSuccess) {
            cryptData.removeSubrange(numBytesEncrypted..<cryptData.count)

        } else {
            print("Error: /(cryptStatus)")
        }

        return cryptData;
    }

}




    func testAES() -> Bool {

        let message     = "secret message"
        let key         = "key890123456"
        let ivString     = "abcdefghijklmnop"   // 16 bytes for AES128

        let messageData = message.data(using:String.Encoding.utf8)!
        let keyData     = key.data(using: .utf8)!
        let ivData      = ivString.data(using: .utf8)!

        let encryptedData = messageData.aesEncrypt( keyData:keyData, ivData:ivData, operation:kCCEncrypt)
        let decryptedData = encryptedData.aesEncrypt( keyData:keyData, ivData:ivData, operation:kCCDecrypt)
        let decrypted     = String(bytes:decryptedData, encoding:String.Encoding.utf8)!

        return message == decrypted

    }

Answer 6

Para cualquiera que no pueda transformar la matriz de bytes en una Cadena

String(data: Data(decrypted), encoding: .utf8)

Este es mi ejemplo de extensión de cadena

extension String {

    func decryptAES(key: String, iv: String) -> String {
        do {
            let encrypted = self
            let key = Array(key.utf8)
            let iv = Array(iv.utf8)
            let aes = try AES(key: key, blockMode: CTR(iv: iv), padding: .noPadding)
            let decrypted = try aes.decrypt(Array(hex: encrypted))
            return String(data: Data(decrypted), encoding: .utf8) ?? ""
        } catch {
            return "Error: /(error)"
        }
    }
}

Answer 7

Swift 4.2

Refactoré el código de @ingconti.

import Foundation
import CommonCrypto

struct AES {

    // MARK: - Value
    // MARK: Private
    private let key: Data
    private let iv: Data


    // MARK: - Initialzier
    init?(key: String, iv: String) {
        guard key.count == kCCKeySizeAES128 || key.count == kCCKeySizeAES256, let keyData = key.data(using: .utf8) else {
            debugPrint("Error: Failed to set a key.")
            return nil
        }

        guard iv.count == kCCBlockSizeAES128, let ivData = iv.data(using: .utf8) else {
            debugPrint("Error: Failed to set an initial vector.")
            return nil
        }


        self.key = keyData
        self.iv  = ivData
    }


    // MARK: - Function
    // MARK: Public
    func encrypt(string: String) -> Data? {
        return crypt(data: string.data(using: .utf8), option: CCOperation(kCCEncrypt))
    }

    func decrypt(data: Data?) -> String? {
        guard let decryptedData = crypt(data: data, option: CCOperation(kCCDecrypt)) else { return nil }
        return String(bytes: decryptedData, encoding: .utf8)
    }

    func crypt(data: Data?, option: CCOperation) -> Data? {
        guard let data = data else { return nil }

        let cryptLength = [UInt8](repeating: 0, count: data.count + kCCBlockSizeAES128).count
        var cryptData   = Data(count: cryptLength)

        let keyLength = [UInt8](repeating: 0, count: kCCBlockSizeAES128).count
        let options   = CCOptions(kCCOptionPKCS7Padding)

        var bytesLength = Int(0)

        let status = cryptData.withUnsafeMutableBytes { cryptBytes in
            data.withUnsafeBytes { dataBytes in
                iv.withUnsafeBytes { ivBytes in
                    key.withUnsafeBytes { keyBytes in
                    CCCrypt(option, CCAlgorithm(kCCAlgorithmAES), options, keyBytes, keyLength, ivBytes, dataBytes, data.count, cryptBytes, cryptLength, &bytesLength)
                    }
                }
            }
        }

        guard UInt32(status) == UInt32(kCCSuccess) else {
            debugPrint("Error: Failed to crypt data. Status /(status)")
            return nil
        }

        cryptData.removeSubrange(bytesLength..<cryptData.count)
        return cryptData
    }
}

Usar así

let password = "UserPassword1!"
let key128   = "1234567890123456"                   // 16 bytes for AES128
let key256   = "12345678901234561234567890123456"   // 32 bytes for AES256
let iv       = "abcdefghijklmnop"                   // 16 bytes for AES128

let aes128 = AES(key: key128, iv: iv)
let aes256 = AES(key: key256, iv: iv)

let encryptedPassword128 = aes128?.encrypt(string: password)
aes128?.decrypt(data: encryptedPassword128)

let encryptedPassword256 = aes256?.encrypt(string: password)
aes256?.decrypt(data: encryptedPassword256)

Resultados