AES128 encryption in swift - ios

Question

I’ve an issue with AES-128 encryption. The encrypted string in iOS is different as compared to Android.
Below is android code :
public class Encryption {
private static final String ALGORITHM = "AES";
private static final String UNICODE_FORMAT = "UTF8";
public static String encryptValue(String valueToEnc) {
try {
Key key = generateKey();
Cipher c = Cipher.getInstance(ALGORITHM);
c.init(Cipher.ENCRYPT_MODE, key);
byte[] encValue = c.doFinal(valueToEnc.getBytes());
String encryptedValue = new Base64().encode(encValue);
String urlEncodeddata = URLEncoder.encode(encryptedValue, "UTF-8");
return urlEncodeddata;
} catch (Exception e) {
}
return valueToEnc;
}
private static Key generateKey() throws Exception {
byte[] keyAsBytes;
keyAsBytes = "MySixteenCharKey".getBytes(UNICODE_FORMAT);
Key key = new SecretKeySpec(keyAsBytes, ALGORITHM);
return key;
}
}

Answer 1

Create string extension and use library CryptoSwift
// String+Addition.swift
import CryptoSwift
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
}
}
and to use
#IBAction func onBtnClicked(_ sender: Any) {
let value = "My value to be encrypted"
let key = "MySixteenCharKey"
print(key!)
let encryptedValue = try! value.aesEncrypt(key: key!)
print(encryptedValue)
}
For citation of this particular encryption code:
The 16 char length key implies AES-128
The code is without iVector, This implies ECB mode
Using padding as pkcs5 or pkcs7 did not made any difference in my case

Answer 2

Try this:
func encryptValue(stringToEncrypt:String) -> String{
var encryptedString: String = ""
let value = "MySixteenCharKey"
let input: Array<UInt8> = Array(stringToEncrypt.utf8)
let key: Array<UInt8> = Array("MySixteenCharKey".utf8)
do {
let encrypted = try AES(key: key, blockMode: .ECB, padding: PKCS7()).encrypt(input)
let base64 = encrypted.toBase64()
encryptedString = base64
} catch {
print(error)
}
return encryptedString
}

Answer 3

Create an extension of String and use this below function for encrypting and decrypting.
extension String {
//MARK: - Encrypt AES Method
/// This method will encrypt and return Cipher string
func aesEncrypt(key: String = "fqJfdzGDvfwbedsKSUGty3VZ9taXxMVw", iv: String = "1234567890123456") -> String {
if let data = self.data(using: String.Encoding.utf8) {
do {
let enc = try AES(key: key, iv: iv, blockMode: .CBC, padding: PKCS7()).encrypt(data.bytes)
let encData = Data(bytes: enc, count: Int(enc.count))
let base64String: String = encData.base64EncodedString(options: NSData.Base64EncodingOptions(rawValue: 0));
return base64String
}
catch let error {
print(error.localizedDescription)
return ""
}
}
return ""
}
//MARK: - Decrypt AES Method
/// This method will decrypt the Cipher string
func aesDecrypt(key: String = "fqJfdzGDvfwbedsKSUGty3VZ9taXxMVw", iv: String = "1234567890123456") -> String {
if let data = Data(base64Encoded: self, options: Data.Base64DecodingOptions.init(rawValue: 0)) {
do {
let dec = try AES(key: key, iv: iv, blockMode: .CBC, padding: PKCS7()).decrypt(data.bytes)
let decData = Data(bytes: dec, count: Int(dec.count))
let result = String(data: decData, encoding: .utf8)
return result ?? ""
}
catch let error {
print(error.localizedDescription)
return ""
}
}
return ""
}
}