sharee.bike-App/LastenradBayern/TINK.Android/Model/Device/DroidCipher.cs

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2.6 KiB
C#
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2021-11-07 19:42:59 +01:00
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Javax.Crypto;
using Javax.Crypto.Spec;
using TINK.Droid.Model.Device;
using TINK.Model.Device;
using Xamarin.Forms;
[assembly: Dependency(typeof(TINK.Droid.Model.Device.DroidCipher))]
namespace TINK.Droid.Model.Device
{
public class DroidCipher : ICipher
{
/// <summary> Encrypt data.</summary>
/// <param name="key">Key to encrypt data.</param>
/// <param name="clear">Data to entrycpt.</param>
/// <returns></returns>
public byte[] Encrypt(byte[] key, byte[] clear)
{
SecretKeySpec skeySpec = new SecretKeySpec(key, 0, 24, "AES");
Cipher cipher = Cipher.GetInstance("AES/ECB/NoPadding");
cipher.Init(CipherMode.EncryptMode, skeySpec);
return cipher.DoFinal(clear);
}
/// <summary> Decrypt data. </summary>
/// <param name="key">Key to decrypt data with.</param>
/// <param name="encrypted">Encrpyted data to decrypt.</param>
/// <returns>Decrypted data.</returns>
public byte[] Decrypt(byte[] key, byte[] encrypted)
{
TestDecrypt();
SecretKeySpec skeySpec = new SecretKeySpec(key, 0, 24, "AES");
Cipher cipher = Cipher.GetInstance("AES/ECB/NoPadding");
cipher.Init(CipherMode.DecryptMode, skeySpec);
return cipher.DoFinal(encrypted);
}
public void TestDecrypt()
{
byte[] decyptedText;
var encryptedText = (new sbyte[] { 50, 51, -40, 64, 42, 82, 97, -24, 20, -39, -15, 126, 119, -110, 47, -18 }).Select(x => (byte)x).ToArray();
var key = (new sbyte[] { -6, 53, 29, -112, 7, -83, -41, -7, 30, 45, -13, -2, -108, -29, -90, 71, 15, -74, -76, 32, 0, 0, 0, 0 }).Select(x => (byte)x).ToArray();
var expecedResult = (new sbyte[] { 19, -66, 55, 18, -106, -92, 70, -40, 117, -87, -19, 124, 19, 54, -18, -82 }).Select(x => (byte)x).ToArray();
SecretKeySpec skeySpec = new SecretKeySpec(key, 0, 24, "AES");
Cipher cipher = Cipher.GetInstance("AES/ECB/NoPadding");
cipher.Init(CipherMode.DecryptMode, skeySpec);
decyptedText = cipher.DoFinal(encryptedText);
if (!expecedResult.SequenceEqual(decyptedText))
{
throw new System.Exception("Decrypted text does not match expectation.");
}
}
}
}