/// <summary>
/// Generate key pair.
/// </summary>
/// <returns></returns>
public override AsymmetricCipherKeyPair GenerateKeyPair()
{
ElGamalParametersGenerator generator2 = new ElGamalParametersGenerator();
generator2.Init(_keySize, _certainty, Common.ThreadSecureRandom.Value);
ElGamalParameters parameters2 = generator2.GenerateParameters();
KeyGenerationParameters parameters = new ElGamalKeyGenerationParameters(Common.ThreadSecureRandom.Value, parameters2);
IAsymmetricCipherKeyPairGenerator generator = new ElGamalKeyPairGenerator();
generator.Init(parameters);
return(generator.GenerateKeyPair());
}
/// <summary>
/// Generates an El Gamal Key pair given its bit size.
/// </summary>
/// <param name="keySize">Bit size for keys of 1024, 2048, 3072 or 4096.</param>
/// <returns></returns>
public AsymmetricCipherKeyPair ElGamalkeyGen(int keySize)
{
var secRand = new SecureRandom();
var probPrime = GetMODRFC3526(keySize);
var elGenertor = GeneratorUtilities.GetKeyPairGenerator("ELGAMAL");
var elBaseGenerator = new BigInteger("2", 16);
var elGamalParameterSet = new ElGamalParameters(probPrime, elBaseGenerator);
var elParams = new ElGamalKeyGenerationParameters(secRand, elGamalParameterSet);
elGenertor.Init(elParams);
var keypair = elGenertor.GenerateKeyPair();
return(keypair);
}
/**
* this test is can take quiet a while
*
* @param size size of key in bits.
*/
private void doTestGeneration(
int size)
{
ElGamalParametersGenerator pGen = new ElGamalParametersGenerator();
pGen.Init(size, 10, new SecureRandom());
ElGamalParameters elParams = pGen.GenerateParameters();
if (elParams.L != 0)
{
Fail("ElGamalParametersGenerator failed to set L to 0 in generated ElGamalParameters");
}
ElGamalKeyGenerationParameters ekgParams = new ElGamalKeyGenerationParameters(new SecureRandom(), elParams);
ElGamalKeyPairGenerator kpGen = new ElGamalKeyPairGenerator();
kpGen.Init(ekgParams);
//
// generate first pair
//
AsymmetricCipherKeyPair pair = kpGen.GenerateKeyPair();
ElGamalPublicKeyParameters pu = (ElGamalPublicKeyParameters)pair.Public;
ElGamalPrivateKeyParameters pv = (ElGamalPrivateKeyParameters)pair.Private;
ElGamalEngine e = new ElGamalEngine();
e.Init(true, new ParametersWithRandom(pu, new SecureRandom()));
byte[] message = Hex.Decode("5468697320697320612074657374");
byte[] pText = message;
byte[] cText = e.ProcessBlock(pText, 0, pText.Length);
e.Init(false, pv);
pText = e.ProcessBlock(cText, 0, cText.Length);
if (!Arrays.AreEqual(message, pText))
{
Fail("generation test failed");
}
}
private void GenerateElGamal(Stream outSecret, Stream outPublic)
{
// Prepare a strong Secure Random with seed
SecureRandom secureRandom = PgpEncryptionUtil.GetSecureRandom();
IAsymmetricCipherKeyPairGenerator dsaKpg = GeneratorUtilities.GetKeyPairGenerator("DSA");
DsaParametersGenerator pGen = new DsaParametersGenerator();
pGen.Init((int)PublicKeyLength.BITS_1024, 80, new SecureRandom()); // DSA is 1024 even for long 2048+ ElGamal keys
DsaParameters dsaParams = pGen.GenerateParameters();
DsaKeyGenerationParameters kgp = new DsaKeyGenerationParameters(secureRandom, dsaParams);
dsaKpg.Init(kgp);
//
// this takes a while as the key generator has to Generate some DSA parameters
// before it Generates the key.
//
AsymmetricCipherKeyPair dsaKp = dsaKpg.GenerateKeyPair();
IAsymmetricCipherKeyPairGenerator elgKpg = GeneratorUtilities.GetKeyPairGenerator("ELGAMAL");
Group elgamalGroup = Precomputed.GetElGamalGroup((int)this.publicKeyLength);
if (elgamalGroup == null)
{
throw new ArgumentException("ElGamal Group not found for key length: " + this.publicKeyLength);
}
Org.BouncyCastle.Math.BigInteger p = elgamalGroup.GetP();
Org.BouncyCastle.Math.BigInteger g = elgamalGroup.GetG();
secureRandom = PgpEncryptionUtil.GetSecureRandom();
ElGamalParameters elParams = new ElGamalParameters(p, g);
ElGamalKeyGenerationParameters elKgp = new ElGamalKeyGenerationParameters(secureRandom, elParams);
elgKpg.Init(elKgp);
//
// this is quicker because we are using preGenerated parameters.
//
AsymmetricCipherKeyPair elgKp = elgKpg.GenerateKeyPair();
DsaElGamalKeyGeneratorUtil.ExportKeyPair(outSecret, outPublic, dsaKp, elgKp, identity, passphrase, true);
}
public void TestElGamal()
{
BigInteger g512 = new BigInteger("153d5d6172adb43045b68ae8e1de1070b6137005686d29d3d73a7749199681ee5b212c9b96bfdcfa5b20cd5e3fd2044895d609cf9b410b7a0f12ca1cb9a428cc", 16);
BigInteger p512 = new BigInteger("9494fec095f3b85ee286542b3836fc81a5dd0a0349b4c239dd38744d488cf8e31db8bcb7d33b41abb9e5a33cca9144b1cef332c94bf0573bf047a3aca98cdf3b", 16);
ElGamalParameters dhParams = new ElGamalParameters(p512, g512);
ElGamalKeyGenerationParameters parameters = new ElGamalKeyGenerationParameters(new SecureRandom(), dhParams); ElGamalKeyPairGenerator kpGen = new ElGamalKeyPairGenerator();
kpGen.Init(parameters);
AsymmetricCipherKeyPair pair = kpGen.GenerateKeyPair();
ElGamalPublicKeyParameters pu1 = (ElGamalPublicKeyParameters)pair.Public;
ElGamalPrivateKeyParameters pv1 = (ElGamalPrivateKeyParameters)pair.Private;
ElGamalPublicKeyParameters pu2 = new ElGamalPublicKeyParameters(pu1.Y, pu1.Parameters);
ElGamalPrivateKeyParameters pv2 = new ElGamalPrivateKeyParameters(pv1.X, pv1.Parameters);
ElGamalPublicKeyParameters pu3 = new ElGamalPublicKeyParameters(pv1.X, pu1.Parameters);
ElGamalPrivateKeyParameters pv3 = new ElGamalPrivateKeyParameters(pu1.Y, pu1.Parameters);
doTest(pu1, pu2, pu3);
doTest(pv1, pv2, pv3);
ElGamalParameters pr1 = pu1.Parameters;
ElGamalParameters pr2 = new ElGamalParameters(pr1.P, pr1.G);
ElGamalParameters pr3 = new ElGamalParameters(pr1.G, pr1.P);
doTest(pr1, pr2, pr3);
pu2 = new ElGamalPublicKeyParameters(pu1.Y, pr2);
pv2 = new ElGamalPrivateKeyParameters(pv1.X, pr2);
doTest(pu1, pu2, pu3);
doTest(pv1, pv2, pv3);
ElGamalTestKeyParameters k1 = new ElGamalTestKeyParameters(false, null);
ElGamalTestKeyParameters k2 = new ElGamalTestKeyParameters(false, null);
ElGamalTestKeyParameters k3 = new ElGamalTestKeyParameters(false, pu1.Parameters);
doTest(k1, k2, k3);
}
public AsymmetricCipherKeyPair GenerateElGamalKeyPair(int keySize, BigInteger prime = null, BigInteger generator = null)
{
ElGamalParameters elGamalParameters;
if (prime != null && generator != null)
{
elGamalParameters = new ElGamalParameters(prime, generator);
}
else
{
var elGamalParameterGenerator = new ElGamalParametersGenerator();
elGamalParameterGenerator.Init(keySize, 64, secureRandom.Generator);
elGamalParameters = elGamalParameterGenerator.GenerateParameters();
}
var keyGenerationParameters = new ElGamalKeyGenerationParameters(secureRandom.Generator, elGamalParameters);
var keyPairGenerator = new ElGamalKeyPairGenerator();
keyPairGenerator.Init(keyGenerationParameters);
return(keyPairGenerator.GenerateKeyPair());
}
public void Init(
KeyGenerationParameters parameters)
{
this.param = (ElGamalKeyGenerationParameters)parameters;
}
private void doTestGP(
int size,
int privateValueSize,
BigInteger g,
BigInteger p)
{
IAsymmetricCipherKeyPairGenerator keyGen = GeneratorUtilities.GetKeyPairGenerator("ElGamal");
// DHParameterSpec elParams = new DHParameterSpec(p, g);
// keyGen.initialize(elParams);
ElGamalParameters elParams = new ElGamalParameters(p, g, privateValueSize);
ElGamalKeyGenerationParameters elKgp = new ElGamalKeyGenerationParameters(
new SecureRandom(), elParams);
keyGen.Init(elKgp);
AsymmetricCipherKeyPair keyPair = keyGen.GenerateKeyPair();
SecureRandom rand = new SecureRandom();
checkKeySize(privateValueSize, keyPair);
IBufferedCipher cipher = CipherUtilities.GetCipher("ElGamal");
cipher.Init(true, new ParametersWithRandom(keyPair.Public, rand));
byte[] inBytes = Encoding.ASCII.GetBytes("This is a test");
if (cipher.GetOutputSize(inBytes.Length) != (size / 8) * 2)
{
Fail("getOutputSize wrong on encryption");
}
byte[] outBytes = cipher.DoFinal(inBytes);
cipher.Init(false, keyPair.Private);
if (cipher.GetOutputSize(outBytes.Length) != (size / 8) - 1)
{
Fail("GetOutputSize wrong on decryption");
}
//
// No Padding - maximum length
//
byte[] modBytes = ((ElGamalPublicKeyParameters)keyPair.Public).Parameters.P.ToByteArray();
byte[] maxInput = new byte[modBytes.Length - 1];
maxInput[0] |= 0x7f;
cipher.Init(true, new ParametersWithRandom(keyPair.Public, rand));
outBytes = cipher.DoFinal(maxInput);
cipher.Init(false, keyPair.Private);
outBytes = cipher.DoFinal(outBytes);
if (!AreEqual(outBytes, maxInput))
{
Fail("NoPadding test failed on decrypt expected "
+ Hex.ToHexString(maxInput) + " got "
+ Hex.ToHexString(outBytes));
}
//
// encrypt/decrypt
//
IBufferedCipher c1 = CipherUtilities.GetCipher("ElGamal");
IBufferedCipher c2 = CipherUtilities.GetCipher("ElGamal");
c1.Init(true, new ParametersWithRandom(keyPair.Public, rand));
byte[] out1 = c1.DoFinal(inBytes);
c2.Init(false, keyPair.Private);
byte[] out2 = c2.DoFinal(out1);
if (!AreEqual(inBytes, out2))
{
Fail(size + " encrypt test failed");
}
//
// encrypt/decrypt with update
//
int outLen = c1.ProcessBytes(inBytes, 0, 2, out1, 0);
outLen += c1.DoFinal(inBytes, 2, inBytes.Length - 2, out1, outLen);
outLen = c2.ProcessBytes(out1, 0, 2, out2, 0);
outLen += c2.DoFinal(out1, 2, out1.Length - 2, out2, outLen);
if (!AreEqual(inBytes, out2))
{
Fail(size + " encrypt with update test failed");
}
//
// public key encoding test
//
// byte[] pubEnc = keyPair.Public.GetEncoded();
byte[] pubEnc = SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(keyPair.Public).GetDerEncoded();
// KeyFactory keyFac = KeyFactory.GetInstance("ElGamal");
// X509EncodedKeySpec pubX509 = new X509EncodedKeySpec(pubEnc);
// DHPublicKeyParameters pubKey = (DHPublicKeyParameters)keyFac.generatePublic(pubX509);
ElGamalPublicKeyParameters pubKey = (ElGamalPublicKeyParameters)
PublicKeyFactory.CreateKey(pubEnc);
ElGamalParameters spec = pubKey.Parameters;
if (!spec.G.Equals(elParams.G) || !spec.P.Equals(elParams.P))
{
Fail(size + " bit public key encoding/decoding test failed on parameters");
}
if (!((ElGamalPublicKeyParameters)keyPair.Public).Y.Equals(pubKey.Y))
{
Fail(size + " bit public key encoding/decoding test failed on y value");
}
/*
* //
* // public key serialisation test
* //
* // TODO Is there some standard this serialization must conform to?
* BinaryFormatter formatter = new BinaryFormatter();
*
* MemoryStream bOut = new MemoryStream();
* // ObjectOutputStream oOut = new ObjectOutputStream(bOut);
* // oOut.writeObject(keyPair.Public);
* formatter.Serialize(bOut, keyPair.Public);
*
* MemoryStream bIn = new MemoryStream(bOut.ToArray(), false);
* // ObjectInputStream oIn = new ObjectInputStream(bIn);
* // pubKey = (DHPublicKeyParameters)oIn.readObject();
* pubKey = (ElGamalPublicKeyParameters) formatter.Deserialize(bIn);
* spec = pubKey.Parameters;
*
* if (!spec.G.Equals(elParams.G) || !spec.P.Equals(elParams.P))
* {
* Fail(size + " bit public key serialisation test failed on parameters");
* }
*
* if (!((ElGamalPublicKeyParameters )keyPair.Public).Y.Equals(pubKey.Y))
* {
* Fail(size + " bit public key serialisation test failed on y value");
* }
*/
//
// private key encoding test
//
// TODO Keys don't support GetEncoded
// byte[] privEnc = keyPair.Private.GetEncoded();
byte[] privEnc = PrivateKeyInfoFactory.CreatePrivateKeyInfo(keyPair.Private).GetDerEncoded();
// PKCS8EncodedKeySpec privPKCS8 = new PKCS8EncodedKeySpec(privEnc);
// DHPrivateKeyParameters privKey = (DHPrivateKeyParameters)keyFac.generatePrivate(privPKCS8);
ElGamalPrivateKeyParameters privKey = (ElGamalPrivateKeyParameters)
PrivateKeyFactory.CreateKey(privEnc);
spec = privKey.Parameters;
if (!spec.G.Equals(elParams.G) || !spec.P.Equals(elParams.P))
{
Fail(size + " bit private key encoding/decoding test failed on parameters");
}
if (!((ElGamalPrivateKeyParameters)keyPair.Private).X.Equals(privKey.X))
{
Fail(size + " bit private key encoding/decoding test failed on y value");
}
/*
* //
* // private key serialisation test
* //
* bOut = new MemoryStream();
* // oOut = new ObjectOutputStream(bOut);
* // oOut.writeObject(keyPair.Private);
* formatter.Serialize(bOut, keyPair.Private);
*
* bIn = new MemoryStream(bOut.ToArray(), false);
* // oIn = new ObjectInputStream(bIn);
* // privKey = (DHPrivateKeyParameters)oIn.readObject();
* privKey = (ElGamalPrivateKeyParameters) formatter.Deserialize(bIn);
* spec = privKey.Parameters;
*
* if (!spec.G.Equals(elParams.G) || !spec.P.Equals(elParams.P))
* {
* Fail(size + " bit private key serialisation test failed on parameters");
* }
*
* if (!((ElGamalPrivateKeyParameters) keyPair.Private).X.Equals(privKey.X))
* {
* Fail(size + " bit private key serialisation test failed on y value");
* }
*/
}
public static int Main(
string[] args)
{
if (args.Length < 2)
{
Console.WriteLine("DsaElGamalKeyRingGenerator [-a] identity passPhrase");
return(0);
}
IAsymmetricCipherKeyPairGenerator dsaKpg = GeneratorUtilities.GetKeyPairGenerator("DSA");
DsaParametersGenerator pGen = new DsaParametersGenerator();
pGen.Init(1024, 80, new SecureRandom());
DsaParameters dsaParams = pGen.GenerateParameters();
DsaKeyGenerationParameters kgp = new DsaKeyGenerationParameters(new SecureRandom(), dsaParams);
dsaKpg.Init(kgp);
//
// this takes a while as the key generator has to Generate some DSA parameters
// before it Generates the key.
//
IAsymmetricCipherKeyPair dsaKp = dsaKpg.GenerateKeyPair();
IAsymmetricCipherKeyPairGenerator elgKpg = GeneratorUtilities.GetKeyPairGenerator("ELGAMAL");
IBigInteger g = new BigInteger("153d5d6172adb43045b68ae8e1de1070b6137005686d29d3d73a7749199681ee5b212c9b96bfdcfa5b20cd5e3fd2044895d609cf9b410b7a0f12ca1cb9a428cc", 16);
IBigInteger p = new BigInteger("9494fec095f3b85ee286542b3836fc81a5dd0a0349b4c239dd38744d488cf8e31db8bcb7d33b41abb9e5a33cca9144b1cef332c94bf0573bf047a3aca98cdf3b", 16);
ElGamalParameters elParams = new ElGamalParameters(p, g);
ElGamalKeyGenerationParameters elKgp = new ElGamalKeyGenerationParameters(new SecureRandom(), elParams);
elgKpg.Init(elKgp);
//
// this is quicker because we are using preGenerated parameters.
//
IAsymmetricCipherKeyPair elgKp = elgKpg.GenerateKeyPair();
Stream out1, out2;
if (args[0].Equals("-a"))
{
if (args.Length < 3)
{
Console.WriteLine("DSAElGamalKeyRingGenerator [-a] identity passPhrase");
return(0);
}
out1 = File.Create("secret.asc");
out2 = File.Create("pub.asc");
ExportKeyPair(out1, out2, dsaKp, elgKp, args[1], args[2].ToCharArray(), true);
}
else
{
out1 = File.Create("secret.bpg");
out2 = File.Create("pub.bpg");
ExportKeyPair(out1, out2, dsaKp, elgKp, args[0], args[1].ToCharArray(), false);
}
out1.Close();
out2.Close();
return(0);
}
private void doTestEnc(
int size,
int privateValueSize,
BigInteger g,
BigInteger p)
{
ElGamalParameters dhParams = new ElGamalParameters(p, g, privateValueSize);
ElGamalKeyGenerationParameters ekgParams = new ElGamalKeyGenerationParameters(new SecureRandom(), dhParams);
ElGamalKeyPairGenerator kpGen = new ElGamalKeyPairGenerator();
kpGen.Init(ekgParams);
//
// generate pair
//
AsymmetricCipherKeyPair pair = kpGen.GenerateKeyPair();
ElGamalPublicKeyParameters pu = (ElGamalPublicKeyParameters)pair.Public;
ElGamalPrivateKeyParameters pv = (ElGamalPrivateKeyParameters)pair.Private;
checkKeySize(privateValueSize, pv);
ElGamalEngine e = new ElGamalEngine();
e.Init(true, pu);
if (e.GetOutputBlockSize() != size / 4)
{
Fail(size + " GetOutputBlockSize() on encryption failed.");
}
byte[] message = Hex.Decode("5468697320697320612074657374");
byte[] pText = message;
byte[] cText = e.ProcessBlock(pText, 0, pText.Length);
e.Init(false, pv);
if (e.GetOutputBlockSize() != (size / 8) - 1)
{
Fail(size + " GetOutputBlockSize() on decryption failed.");
}
pText = e.ProcessBlock(cText, 0, cText.Length);
if (!Arrays.AreEqual(message, pText))
{
Fail(size + " bit test failed");
}
e.Init(true, pu);
byte[] bytes = new byte[e.GetInputBlockSize() + 2];
try
{
e.ProcessBlock(bytes, 0, bytes.Length);
Fail("out of range block not detected");
}
catch (DataLengthException)
{
// expected
}
try
{
bytes[0] = (byte)0xff;
e.ProcessBlock(bytes, 0, bytes.Length - 1);
Fail("out of range block not detected");
}
catch (DataLengthException)
{
// expected
}
try
{
bytes[0] = (byte)0x7f;
e.ProcessBlock(bytes, 0, bytes.Length - 1);
}
catch (DataLengthException)
{
Fail("in range block failed");
}
}
