private static void SetSBox(Gost28147Mac mac, byte[] sbox)
{
var field = mac.GetType().GetField("S", BindingFlags.Instance | BindingFlags.NonPublic);
var s = (byte[])field.GetValue(mac);
sbox.CopyTo(s, 0);
}
public static byte[] Compute_gost28147(byte[] paket, byte[] key)
{
Gost28147Mac gost = new Gost28147Mac();
KeyParameter param = new KeyParameter(key);
gost.Init(param);
byte[] output = new byte[gost.GetMacSize()];
gost.DoFinal(output, 0);
return(output);
}
/// <summary>
/// IMPLEMENTACIJA JE TAKVA DA VRATI 4 bajta
/// </summary>
/// <param name="paket"></param>
/// <param name="key"></param>
/// <returns></returns>
public static byte[] Compute_gost28147(byte[] paket, byte[] key)
{
Gost28147Mac gost = new Gost28147Mac();
KeyParameter param = new KeyParameter(key, 0, key.Length);
gost.Init(param);
gost.BlockUpdate(key, 0, key.Length);
var macS = gost.GetMacSize();
byte[] output = new byte[macS];
int b = gost.DoFinal(output, 0);
return(output);
}
private static void CheckMac(byte[] key, byte[] cek, byte[] data, byte[] mac)
{
var m = new Gost28147Mac();
var keyPrm = ParameterUtilities.CreateKeyParameter("GOST", key);
m.Init(keyPrm);
var cekmac = new byte[4];
m.BlockUpdate(data, 0, data.Length);
m.DoFinal(cekmac, 0);
if (!mac.SequenceEqual(cekmac))
{
throw new CryptographicException("Неверный ПИН-код");
}
}
public ITestResult Perform()
{
// test1
IMac mac = new Gost28147Mac();
KeyParameter key = new KeyParameter(gkeyBytes1);
mac.Init(key);
mac.BlockUpdate(input3, 0, input3.Length);
byte[] outBytes = new byte[4];
mac.DoFinal(outBytes, 0);
if (!Arrays.AreEqual(outBytes, output7))
{
return(new SimpleTestResult(false, Name + ": Failed test 1 - expected "
+ Hex.ToHexString(output7)
+ " got " + Hex.ToHexString(outBytes)));
}
// test2
key = new KeyParameter(gkeyBytes2);
ParametersWithSBox gparam = new ParametersWithSBox(key, Gost28147Engine.GetSBox("E-A"));
mac.Init(gparam);
mac.BlockUpdate(input4, 0, input4.Length);
outBytes = new byte[4];
mac.DoFinal(outBytes, 0);
if (!Arrays.AreEqual(outBytes, output8))
{
return(new SimpleTestResult(false, Name + ": Failed test 2 - expected "
+ Hex.ToHexString(output8)
+ " got " + Hex.ToHexString(outBytes)));
}
return(new SimpleTestResult(true, Name + ": Okay"));
}
private void CheckMac(byte[] cekDecrypted, byte[] kek)
{
var cekmac = new byte[4];
var mac = new Gost28147Mac();
var key = ParameterUtilities.CreateKeyParameter("GOST", kek);
var prms = new ParametersWithIV(key, UKM);
mac.Init(prms);
SetSBox(mac, Gost28147_SBox);
mac.BlockUpdate(cekDecrypted, 0, cekDecrypted.Length);
mac.DoFinal(cekmac, 0);
for (int i = 0; i < 4; ++i)
{
if (cekmac[i] != MAC[i])
{
throw new CryptographicException("CEK decryption error, MAC values do not match.");
}
}
}