private static void TestTwoCycle(int i1, int i2, byte[] permutation)
{
Array.Copy(Identity, permutation, 64);
permutation[i1] = (byte)i2;
permutation[i2] = (byte)i1;
PermutationNetwork pnwk = new PermutationNetwork(permutation);
Assert.AreEqual(1UL << i2, pnwk.Permute(1UL << i1));
Assert.AreEqual(1UL << i1, pnwk.Permute(1UL << i2));
}
public void Test0_PermutationNetwork()
{
byte[] _IPTranspose = new byte[]
{
57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7,
56, 48, 40, 32, 24, 16, 8, 0, 58, 50, 42, 34, 26, 18, 10, 2,
60, 52, 44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6
};
byte[] _IPTransposeReversed = new byte[64];
for (int i = 0; i < 64; ++i)
{
_IPTransposeReversed[i] = _IPTranspose[63 - i];
}
byte[] _IPTransposeInversed = new byte[64];
for (int i = 0; i < 64; ++i)
{
_IPTransposeInversed[_IPTranspose[i]] = (byte)i;
}
byte[] _IPTransposeInversedReversed = new byte[64];
for (int i = 0; i < 64; ++i)
{
_IPTransposeInversedReversed[_IPTranspose[63 - i]] = (byte)i;
}
var network = new PermutationNetwork(_IPTransposeInversedReversed);
Random random = new Random(123);
byte[] buf = new byte[8];
for (int i = 0; i < 10000; ++i)
{
random.NextBytes(buf);
ulong value = BitConverter.ToUInt64(buf, 0);
ulong expected = Bitops.BitPermutation(value, _IPTranspose);
ulong actual = network.Permute(value);
Assert.AreEqual(expected, actual);
}
}
public void TestPermutationNetwork()
{
byte[] permutation = new byte[64];
// Identity permutation
for (byte i = 0; i < 64; i++)
{
Identity[i] = i;
}
for (int i1 = 0; i1 < 62; i1++)
{
for (int i2 = i1 + 1; i2 < 64; i2++)
{
TestTwoCycle(i1, i2, permutation);
}
}
Array.Copy(Identity, permutation, 64);
PermutationNetwork pnwk = new PermutationNetwork(permutation);
Assert.AreEqual(56ul, pnwk.Permute(56));
// Swap unit and two's bits
permutation[0] = 1;
permutation[1] = 0;
pnwk = new PermutationNetwork(permutation);
Assert.AreEqual(1ul, pnwk.Permute(2));
Assert.AreEqual(2ul, pnwk.Permute(1));
Assert.AreEqual(3ul, pnwk.Permute(3));
Assert.AreEqual(5ul, pnwk.Permute(6));
Assert.AreEqual(6ul, pnwk.Permute(5));
// Cycle the bottom four bits
permutation[0] = 1;
permutation[1] = 2;
permutation[2] = 3;
permutation[3] = 0;
pnwk = new PermutationNetwork(permutation);
Assert.AreEqual(2ul, pnwk.Permute(1));
Assert.AreEqual(4ul, pnwk.Permute(2));
Assert.AreEqual(8ul, pnwk.Permute(4));
Assert.AreEqual(1ul, pnwk.Permute(8));
Assert.AreEqual(3ul, pnwk.Permute(9));
// Random permutation
Random rnd = new Random(0);
for (int i = 0; i < 63; i++)
{
int swapIndex = rnd.Next(64);
byte b = permutation[i];
permutation[i] = permutation[swapIndex];
permutation[swapIndex] = b;
}
pnwk = new PermutationNetwork(permutation);
ulong testVal = ((ulong)rnd.Next() << 32) | (uint)rnd.Next();
ulong resultVal = pnwk.Permute(testVal);
TestPerm(permutation, testVal, resultVal);
}