public void TestECDH()
{
byte[] kA = new byte[X448.ScalarSize];
byte[] kB = new byte[X448.ScalarSize];
byte[] qA = new byte[X448.PointSize];
byte[] qB = new byte[X448.PointSize];
byte[] sA = new byte[X448.PointSize];
byte[] sB = new byte[X448.PointSize];
for (int i = 1; i <= 100; ++i)
{
// Each party generates an ephemeral private key, ...
Random.NextBytes(kA);
Random.NextBytes(kB);
// ... publishes their public key, ...
X448.ScalarMultBase(kA, 0, qA, 0);
X448.ScalarMultBase(kB, 0, qB, 0);
// ... computes the shared secret, ...
X448.ScalarMult(kA, 0, qB, 0, sA, 0);
X448.ScalarMult(kB, 0, qA, 0, sB, 0);
// ... which is the same for both parties.
Assert.IsTrue(Arrays.AreEqual(sA, sB), "ECDH #" + i);
}
}
private static void CheckX448Vector(String sk, String su, String se, String text)
{
byte[] k = Hex.Decode(sk);
byte[] u = Hex.Decode(su);
byte[] r = new byte[56];
X448.ScalarMult(k, 0, u, 0, r, 0);
CheckValue(r, text, se);
}
public void GenerateSecret(X448PublicKeyParameters publicKey, byte[] buf, int off)
{
byte[] encoded = new byte[X448.PointSize];
publicKey.Encode(encoded, 0);
if (!X448.CalculateAgreement(data, 0, encoded, 0, buf, off))
{
throw new InvalidOperationException("X448 agreement failed");
}
}
private static void CheckX448Vector(string sk, string su, string se, string text)
{
byte[] k = Hex.Decode(sk);
Assert.AreEqual(X448.ScalarSize, k.Length);
byte[] u = Hex.Decode(su);
Assert.AreEqual(X448.PointSize, u.Length);
byte[] r = new byte[X448.PointSize];
X448.ScalarMult(k, 0, u, 0, r, 0);
CheckValue(r, text, se);
}
public void TestConsistency()
{
byte[] u = new byte[X448.PointSize]; u[0] = 5;
byte[] k = new byte[X448.ScalarSize];
byte[] rF = new byte[X448.PointSize];
byte[] rV = new byte[X448.PointSize];
for (int i = 1; i <= 100; ++i)
{
Random.NextBytes(k);
X448.ScalarMultBase(k, 0, rF, 0);
X448.ScalarMult(k, 0, u, 0, rV, 0);
Assert.IsTrue(Arrays.AreEqual(rF, rV), "Consistency #" + i);
}
}
private static void CheckECDHVector(string sA, string sAPub, string sB, string sBPub, string sK, string text)
{
byte[] a = Hex.Decode(sA);
byte[] b = Hex.Decode(sB);
byte[] aPub = new byte[56];
X448.ScalarMultBase(a, 0, aPub, 0);
CheckValue(aPub, text, sAPub);
byte[] bPub = new byte[56];
X448.ScalarMultBase(b, 0, bPub, 0);
CheckValue(bPub, text, sBPub);
byte[] aK = new byte[56];
X448.ScalarMult(a, 0, bPub, 0, aK, 0);
CheckValue(aK, text, sK);
byte[] bK = new byte[56];
X448.ScalarMult(b, 0, aPub, 0, bK, 0);
CheckValue(bK, text, sK);
}
private static void CheckIterated(int count)
{
Assert.AreEqual(X448.PointSize, X448.ScalarSize);
byte[] k = new byte[X448.PointSize]; k[0] = 5;
byte[] u = new byte[X448.PointSize]; u[0] = 5;
byte[] r = new byte[X448.PointSize];
int iterations = 0;
while (iterations < count)
{
X448.ScalarMult(k, 0, u, 0, r, 0);
Array.Copy(k, 0, u, 0, X448.PointSize);
Array.Copy(r, 0, k, 0, X448.PointSize);
switch (++iterations)
{
case 1:
CheckValue(k, "Iterated @1",
"3f482c8a9f19b01e6c46ee9711d9dc14fd4bf67af30765c2ae2b846a4d23a8cd0db897086239492caf350b51f833868b9bc2b3bca9cf4113");
break;
case 1000:
CheckValue(k, "Iterated @1000",
"aa3b4749d55b9daf1e5b00288826c467274ce3ebbdd5c17b975e09d4af6c67cf10d087202db88286e2b79fceea3ec353ef54faa26e219f38");
break;
case 1000000:
CheckValue(k, "Iterated @1000000",
"077f453681caca3693198420bbe515cae0002472519b3e67661a7e89cab94695c8f4bcd66e61b9b9c946da8d524de3d69bd9d9d66b997e37");
break;
default:
break;
}
}
}
private static void CheckECDHVector(string sA, string sAPub, string sB, string sBPub, string sK, string text)
{
byte[] a = Hex.Decode(sA);
Assert.AreEqual(X448.ScalarSize, a.Length);
byte[] b = Hex.Decode(sB);
Assert.AreEqual(X448.ScalarSize, b.Length);
byte[] aPub = new byte[X448.PointSize];
X448.ScalarMultBase(a, 0, aPub, 0);
CheckValue(aPub, text, sAPub);
byte[] bPub = new byte[X448.PointSize];
X448.ScalarMultBase(b, 0, bPub, 0);
CheckValue(bPub, text, sBPub);
byte[] aK = new byte[X448.PointSize];
X448.ScalarMult(a, 0, bPub, 0, aK, 0);
CheckValue(aK, text, sK);
byte[] bK = new byte[X448.PointSize];
X448.ScalarMult(b, 0, aPub, 0, bK, 0);
CheckValue(bK, text, sK);
}
public void SetUp()
{
X448.Precompute();
}
public X448PublicKeyParameters GeneratePublicKey()
{
byte[] publicKey = new byte[X448.PointSize];
X448.GeneratePublicKey(data, 0, publicKey, 0);
return(new X448PublicKeyParameters(publicKey, 0));
}
public X448PrivateKeyParameters(SecureRandom random)
: base(true)
{
X448.GeneratePrivateKey(random, data);
}
public void GenerateSecret(X448PublicKeyParameters publicKey, byte[] buf, int off)
{
byte[] encoded = new byte[X448.PointSize];
publicKey.Encode(encoded, 0);
X448.ScalarMult(data, 0, encoded, 0, buf, off);
}