public static void TestTextEncryption(string message = "Programming .NET Security", int keySize = 1024, ElGamalPaddingMode padding = ElGamalPaddingMode.Zeros)
{
Console.WriteLine();
Console.WriteLine("-- Testing string encryption ---");
var plaintext = Encoding.Default.GetBytes(message);
ElGamal algorithm = new ElGamalManaged();
algorithm.KeySize = keySize;
algorithm.Padding = padding;
string parametersXML = algorithm.ToXmlString(true);
Console.WriteLine("\n{0}\n", PrettifyXML(parametersXML));
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithm.ToXmlString(false));
byte[] ciphertext = encryptAlgorithm.EncryptData(plaintext);
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithm.ToXmlString(true));
byte[] candidatePlaintext = decryptAlgorithm.DecryptData(ciphertext);
Console.WriteLine("Original string: '{0}'", message);
Console.WriteLine("Decrypted string: '{0}'", Encoding.Default.GetString(candidatePlaintext));
Console.WriteLine("Byte arrays equal: {0}", plaintext.SequenceEqual(candidatePlaintext));
Console.WriteLine();
}
public void TestTextEncryption()
{
int keySize;
ElGamalPaddingMode padding = ElGamalPaddingMode.Zeros;
string message = "Programming .NET Security";
var plaintext = Encoding.Default.GetBytes(message);
ElGamal algorithm = new ElGamalManaged();
algorithm.Padding = padding;
for (keySize = 384; keySize <= 1088; keySize += 8)
{
algorithm.KeySize = keySize;
string parametersXML = algorithm.ToXmlString(true);
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithm.ToXmlString(false));
byte[] ciphertext = encryptAlgorithm.EncryptData(plaintext);
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithm.ToXmlString(true));
byte[] candidatePlaintext = decryptAlgorithm.DecryptData(ciphertext);
CollectionAssert.AreEqual(plaintext, candidatePlaintext, "Failed at keysize: " + keySize.ToString());
}
}
public void TestZero_DifferentPaddingMode()
{
ElGamal algorithm = new ElGamalManaged();
algorithm.KeySize = 384;
ElGamalPaddingMode[] paddingModes = { ElGamalPaddingMode.LeadingZeros, ElGamalPaddingMode.Zeros };
foreach (var paddingMode in paddingModes)
{
algorithm.Padding = paddingMode;
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithm.ToXmlString(false));
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithm.ToXmlString(true));
var z = new BigInteger(0);
var z_enc = encryptAlgorithm.EncryptData(z.getBytes());
var z_dec = decryptAlgorithm.DecryptData(z_enc);
var zero_array = new byte[z_dec.Length];
Array.Clear(zero_array, 0, zero_array.Length - 1);
CollectionAssert.AreEqual(zero_array, z_dec, "Failed on padding mode: " + paddingMode.ToString());
}
}
public void TestRandomBI()
{
// Failed test because of zeroes
ElGamal algorithm = new ElGamalManaged();
algorithm.Padding = ElGamalPaddingMode.LeadingZeros;
for (algorithm.KeySize = 384; algorithm.KeySize <= 1088; algorithm.KeySize += 8)
{
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithm.ToXmlString(false));
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithm.ToXmlString(true));
var z = new BigInteger();
z.genRandomBits(new Random().Next(1, 2241), new RNGCryptoServiceProvider());
var z_enc = encryptAlgorithm.EncryptData(z.getBytes());
var z_dec = decryptAlgorithm.DecryptData(z_enc);
CollectionAssert.AreEqual(z.getBytes(), z_dec);
}
}
public void TestZero()
{
ElGamal algorithm = new ElGamalManaged();
algorithm.Padding = ElGamalPaddingMode.Zeros;
for (int keySize = 384; keySize <= 1088; keySize += 8)
{
algorithm.KeySize = keySize;
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithm.ToXmlString(false));
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithm.ToXmlString(true));
var z = new BigInteger(0);
var z_enc = encryptAlgorithm.EncryptData(z.getBytes());
var z_dec = decryptAlgorithm.DecryptData(z_enc);
var zero_array = new byte[z_dec.Length];
Array.Clear(zero_array, 0, zero_array.Length - 1);
CollectionAssert.AreEqual(zero_array, z_dec);
}
}
//[Fact] TODO: Fix text encryption and re-enable the test (implement ANSIX923 or PKCS97 padding)
public void TestTextEncryption()
{
int keySize;
var padding = ElGamalPaddingMode.TrailingZeros;
var message = "Programming .NET Security";
var plaintext = Encoding.Default.GetBytes(message);
ElGamal algorithm = new ElGamalManaged()
{
Padding = padding
};
for (keySize = 384; keySize <= 1088; keySize += 8)
{
algorithm.KeySize = keySize;
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithm.ToXmlString(false));
var ciphertext = encryptAlgorithm.EncryptData(plaintext);
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithm.ToXmlString(true));
var candidatePlaintext = decryptAlgorithm.DecryptData(ciphertext);
Assert.True(plaintext.Equals(candidatePlaintext), $"Failed at keysize: {keySize}");
}
}
public void TestZero()
{
ElGamalPaddingMode[] paddingModes = { ElGamalPaddingMode.LeadingZeros, ElGamalPaddingMode.TrailingZeros };
foreach (var paddingMode in paddingModes)
{
for (var keySize = 384; keySize <= 1088; keySize += 8)
{
ElGamal algorithm = new ElGamalManaged
{
Padding = paddingMode,
KeySize = keySize
};
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithm.ToXmlString(false));
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithm.ToXmlString(true));
var z = new BigInteger(0);
var z_bytes = z.ToByteArray();
var z_enc_bytes = encryptAlgorithm.EncryptData(z_bytes);
var z_dec_bytes = decryptAlgorithm.DecryptData(z_enc_bytes);
var z_dec = new BigInteger(z_dec_bytes);
Assert.Equal(z, z_dec);
}
}
}
public static void TestMultiplication_Batch()
{
Console.WriteLine();
Console.WriteLine("-- Testing multiplication in batch ------");
var rnd = new Random();
for (int i = 0; i < 3; i++)
// testing for 3 sets of keys
{
Console.WriteLine("- Testing for key No.{0} -", i + 1);
ElGamal algorithm = new ElGamalManaged();
algorithm.KeySize = 384;
algorithm.Padding = ElGamalPaddingMode.LeadingZeros;
string parametersXML = algorithm.ToXmlString(true);
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithm.ToXmlString(false));
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithm.ToXmlString(true));
int error_counter = 0;
for (int j = 0; j < 50; j++)
// testing for 50 pairs of random numbers
{
var a = new BigInteger(rnd.Next());
var b = new BigInteger(rnd.Next());
var a_bytes = encryptAlgorithm.EncryptData(a.getBytes());
var b_bytes = encryptAlgorithm.EncryptData(b.getBytes());
var c_bytes = encryptAlgorithm.Multiply(a_bytes, b_bytes);
var dec_c = new BigInteger(decryptAlgorithm.DecryptData(c_bytes));
var dec_a = new BigInteger(decryptAlgorithm.DecryptData(a_bytes));
var dec_b = new BigInteger(decryptAlgorithm.DecryptData(b_bytes));
var ab_result = a * b;
if (dec_c != ab_result)
{
error_counter++;
Console.WriteLine("Failure #{0}", error_counter);
Console.WriteLine("Key = {0}", PrettifyXML(parametersXML));
Console.WriteLine("Encrypted: {0} * {1} = {2}", dec_a.ToString(), dec_b.ToString(), dec_c.ToString());
Console.WriteLine("Plaintext: {0} * {1} = {2}", a.ToString(), b.ToString(), ab_result.ToString());
Console.WriteLine();
}
}
Console.WriteLine("There are {0}/50 cases that do not pass the test", error_counter);
Console.WriteLine();
}
}
public void TestMultiplication_Batch()
{
var rnd = new Random();
for (int keySize = 384; keySize <= 1088; keySize += 8)
{
for (int i = 0; i < 3; i++)
// testing for 3 sets of keys
{
ElGamal algorithm = new ElGamalManaged();
algorithm.KeySize = keySize;
algorithm.Padding = ElGamalPaddingMode.LeadingZeros;
string parametersXML = algorithm.ToXmlString(true);
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithm.ToXmlString(false));
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithm.ToXmlString(true));
int error_counter = 0;
for (int j = 0; j < 50; j++)
// testing for 50 pairs of random numbers
{
var a = new BigInteger(rnd.Next());
var b = new BigInteger(rnd.Next());
var a_bytes = encryptAlgorithm.EncryptData(a.getBytes());
var b_bytes = encryptAlgorithm.EncryptData(b.getBytes());
var c_bytes = encryptAlgorithm.Multiply(a_bytes, b_bytes);
var dec_c = new BigInteger(decryptAlgorithm.DecryptData(c_bytes));
var dec_a = new BigInteger(decryptAlgorithm.DecryptData(a_bytes));
var dec_b = new BigInteger(decryptAlgorithm.DecryptData(b_bytes));
var ab_result = a * b;
if (dec_c != ab_result)
{
error_counter++;
}
Assert.AreEqual(dec_c, ab_result);
}
}
}
}
public void TestMultiplication_Batch()
{
var iterations = 3;
var rnd = new Random();
for (var keySize = 384; keySize <= 1088; keySize += 8)
{
for (var i = 0; i < iterations; i++)
{
ElGamal algorithm = new ElGamalManaged
{
KeySize = keySize,
Padding = ElGamalPaddingMode.BigIntegerPadding
};
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithm.ToXmlString(false));
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithm.ToXmlString(true));
var a = new BigInteger(rnd.Next());
var b = new BigInteger(rnd.Next());
var a_bytes = encryptAlgorithm.EncryptData(a.ToByteArray());
var b_bytes = encryptAlgorithm.EncryptData(b.ToByteArray());
var c_bytes = encryptAlgorithm.Multiply(a_bytes, b_bytes);
var dec_c = new BigInteger(decryptAlgorithm.DecryptData(c_bytes));
var ab_result = a * b;
Assert.True(dec_c == ab_result, $"{Environment.NewLine}{Environment.NewLine}" +
$"Algorithm parameters (TRUE):{Environment.NewLine}" +
$"{algorithm.ToXmlString(true)}{Environment.NewLine}{Environment.NewLine}" +
$"Algorithm parameters (FALSE):{Environment.NewLine}" +
$"{algorithm.ToXmlString(false)}{Environment.NewLine}{Environment.NewLine}" +
$"a : {a}{Environment.NewLine}{Environment.NewLine}" +
$"b : {b}{Environment.NewLine}{Environment.NewLine}" +
$"a*b : {ab_result}{Environment.NewLine}{Environment.NewLine}" +
$"dec_c : {dec_c}");
}
}
}
private static long ProfileEncryptedMUL(int iterations, int keyl)
{
// clean up
GC.Collect();
GC.WaitForPendingFinalizers();
GC.Collect();
var rnd = new Random();
// prepare and warm up
ElGamal algorithm = new ElGamalManaged();
algorithm.KeySize = keyl;
algorithm.Padding = ElGamalPaddingMode.LeadingZeros;
string parametersXML = algorithm.ToXmlString(true);
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithm.ToXmlString(false));
var a = new BigInteger(rnd.Next(65536));
var a_bytes = encryptAlgorithm.EncryptData(a.getBytes());
var b = new BigInteger(rnd.Next(65536));
var b_bytes = encryptAlgorithm.EncryptData(b.getBytes());
var c_bytes = encryptAlgorithm.Multiply(a_bytes, b_bytes);
var watch = Stopwatch.StartNew();
for (int i = 0; i < iterations; i++)
{
c_bytes = encryptAlgorithm.Multiply(a_bytes, b_bytes);
}
watch.Stop();
return(watch.Elapsed.Ticks);
}
public void TestRandomBigInteger()
{
var rnd = new Random();
var rng = new RNGCryptoServiceProvider();
for (var keySize = 384; keySize <= 1088; keySize += 8)
{
ElGamal algorithm = new ElGamalManaged
{
Padding = ElGamalPaddingMode.BigIntegerPadding,
KeySize = keySize
};
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithm.ToXmlString(false));
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithm.ToXmlString(true));
var z = new BigInteger(); // Plaintext that is bigger than one block needs different padding,
// and the encryption loses homomorphic properties
z = z.GenRandomBits(rnd.Next(1, ((ElGamalManaged)algorithm).KeyStruct.getPlaintextBlocksize()), rng);
var z_enc_bytes = encryptAlgorithm.EncryptData(z.ToByteArray());
var z_dec_bytes = decryptAlgorithm.DecryptData(z_enc_bytes);
var z_dec = new BigInteger(z_dec_bytes);
Assert.True(z == z_dec, $"{Environment.NewLine}{Environment.NewLine}" +
$"Algorithm parameters (TRUE):{Environment.NewLine}" +
$"{algorithm.ToXmlString(true)}{Environment.NewLine}{Environment.NewLine}" +
$"Algorithm parameters (FALSE):{Environment.NewLine}" +
$"{algorithm.ToXmlString(false)}{Environment.NewLine}{Environment.NewLine}" +
$"z: {z}{Environment.NewLine}{Environment.NewLine}" +
$"z_dec: {z_dec}");
}
}
public void TestSpecificCases()
{
{
var algorithmParamsTRUE = "<ElGamalKeyValue><P>hVWJyw9KZna4jNwese2+r6D4li7yXRG6/YIwsmPYY66NGpAigpYJR02IamdmHFe4+UznfJ3G4JZ3dpiI+o6PcHHEMPr88UlxoF9ZDAZ1XWmP7e7MpPPD/U1SK0hBy1bDy0O3Vx7ZAxD842hE</P><G>zjhHbkeMnG5SeApYj2+FDKWMx/+TN4rNrqk51e11C+uWo86oLCvTKqTOWDYAnbN15PrFuAr/bF35Alh3U2qytZCQmagh3E9VaqaRysS5aUvXfnBxlL0x+FvNtAK92r+eNMGE1UPZxVpk1DEu</G><Y>Vu0lxxhOIqluDQary3wx7A8J/cZ5B2xrtXQm8IiZz7b85yjcBr4I5T46JcbCJrLdheRzqdFH+/yE1Hegc/AJRU8mpAeikGTeuZ9wbLN0/QKfu67s6WtjVcjJNPCj+2LkKsN0T4f41+yEtho5</Y><Padding>LeadingZeros</Padding><X>1herKmqCq0sL+4DztH/DNbT27rylaa8L3a0Lb+z1r1aRih6Z+Rq3TtR6N0Q+kKDR8rzifq2G5xBs1MTYLOzcobmQYyXPJDHct/thTKsgaWD7J8P9Yrjj4hKP6iO6RHs1g4t2vuewLcPikFsn</X></ElGamalKeyValue>";
var algorithmParamsFALSE = "<ElGamalKeyValue><P>hVWJyw9KZna4jNwese2+r6D4li7yXRG6/YIwsmPYY66NGpAigpYJR02IamdmHFe4+UznfJ3G4JZ3dpiI+o6PcHHEMPr88UlxoF9ZDAZ1XWmP7e7MpPPD/U1SK0hBy1bDy0O3Vx7ZAxD842hE</P><G>zjhHbkeMnG5SeApYj2+FDKWMx/+TN4rNrqk51e11C+uWo86oLCvTKqTOWDYAnbN15PrFuAr/bF35Alh3U2qytZCQmagh3E9VaqaRysS5aUvXfnBxlL0x+FvNtAK92r+eNMGE1UPZxVpk1DEu</G><Y>Vu0lxxhOIqluDQary3wx7A8J/cZ5B2xrtXQm8IiZz7b85yjcBr4I5T46JcbCJrLdheRzqdFH+/yE1Hegc/AJRU8mpAeikGTeuZ9wbLN0/QKfu67s6WtjVcjJNPCj+2LkKsN0T4f41+yEtho5</Y><Padding>LeadingZeros</Padding></ElGamalKeyValue>";
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithmParamsFALSE);
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithmParamsTRUE);
var z = new BigInteger();
BigInteger.TryParse("478878612704556930", out z);
var z_enc_bytes = encryptAlgorithm.EncryptData(z.ToByteArray());
var z_dec_bytes = decryptAlgorithm.DecryptData(z_enc_bytes);
var z_dec = new BigInteger(z_dec_bytes);
Assert.Equal(z, z_dec);
}
{
ElGamal algorithm = new ElGamalManaged
{
KeySize = 384,
Padding = ElGamalPaddingMode.TrailingZeros
};
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithm.ToXmlString(false));
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithm.ToXmlString(true));
var z = new BigInteger();
BigInteger.TryParse("427514703128554143101621639680", out z);
var z_enc_bytes = encryptAlgorithm.EncryptData(z.ToByteArray());
var z_dec_bytes = decryptAlgorithm.DecryptData(z_enc_bytes);
var z_dec = new BigInteger(z_dec_bytes);
Assert.Equal(z, z_dec);
}
{
var algorithmParamsTRUE = "<ElGamalKeyValue><P>xWq9Kme204HeAuTBZenPYad7JYuqoSeKHveDlluGxOA3huROBtgA1LKT7GvHaohB</P><G>+kaqpuuPc4ziGbOftkw7HkSgOiovsPHvtPVLnVTsDmxLHDWA+0l08HFNz0RPQaAm</G><Y>D3oD1ePykN0L+h389YzXQRvYgKfQwgbPT6lP3sze75A7sOTfw4Y8qMQeGmM/yIcz</Y><Padding>TrailingZeros</Padding><X>c/v9OR4JwIUblP/xluK+6RErZTyLuJRwIb9gTjuW/1zzJkcjUu2HOchXbSW9zLw+</X></ElGamalKeyValue>";
var algorithmParamsFALSE = "<ElGamalKeyValue><P>xWq9Kme204HeAuTBZenPYad7JYuqoSeKHveDlluGxOA3huROBtgA1LKT7GvHaohB</P><G>+kaqpuuPc4ziGbOftkw7HkSgOiovsPHvtPVLnVTsDmxLHDWA+0l08HFNz0RPQaAm</G><Y>D3oD1ePykN0L+h389YzXQRvYgKfQwgbPT6lP3sze75A7sOTfw4Y8qMQeGmM/yIcz</Y><Padding>TrailingZeros</Padding></ElGamalKeyValue>";
ElGamal encryptAlgorithm = new ElGamalManaged();
encryptAlgorithm.FromXmlString(algorithmParamsFALSE);
ElGamal decryptAlgorithm = new ElGamalManaged();
decryptAlgorithm.FromXmlString(algorithmParamsTRUE);
var a = new BigInteger(248284864);
var b = new BigInteger(674886484);
var a_bytes = encryptAlgorithm.EncryptData(a.ToByteArray());
var b_bytes = encryptAlgorithm.EncryptData(b.ToByteArray());
var c_bytes = encryptAlgorithm.Multiply(a_bytes, b_bytes);
var dec_c = new BigInteger(decryptAlgorithm.DecryptData(c_bytes));
var ab_result = a * b;
Assert.Equal(ab_result, dec_c);
}
{
ElGamal algorithm = new ElGamalManaged
{
KeySize = 384,
Padding = ElGamalPaddingMode.BigIntegerPadding
};
var a = new BigInteger(2048);
var a_bytes = algorithm.EncryptData(a.ToByteArray());
var dec_a = new BigInteger(algorithm.DecryptData(a_bytes));
Assert.Equal(a, dec_a);
}
{
ElGamal algorithm = new ElGamalManaged
{
KeySize = 384,
Padding = ElGamalPaddingMode.BigIntegerPadding
};
var a = new BigInteger(138);
var a_bytes = algorithm.EncryptData(a.ToByteArray());
var dec_a = new BigInteger(algorithm.DecryptData(a_bytes));
Assert.Equal(a, dec_a);
}
}