AES128 encryption in swift

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:

1. The 16 char length key implies AES-128
2. The code is without iVector, This implies ECB mode
3. Using padding as pkcs5 or pkcs7 did not made any difference in my case