public void BitCalculatorTest()
{
Assert.AreEqual(2, BitCalculator.Calculate("1", "1"));
Assert.AreEqual(4, BitCalculator.Calculate("10", "10"));
Assert.AreEqual(2, BitCalculator.Calculate("10", "0"));
Assert.AreEqual(3, BitCalculator.Calculate("10", "1"));
}
/// <summary>
/// Encrypts data using a low-entropy packing scheme.
/// </summary>
/// <param name="path">The path to the data to encrypt.</param>
/// <param name="encryptedPath">The path to write the encrypted data to.</param>
/// <param name="padding">The percentage of padding to add, where 0 means no extra padding, 100 means to double the size and 200 means to tripple the size. This can be a number between 0 and 1000.</param>
/// <param name="key">When this function returns, this is the 32-bit decryption key.</param>
/// <param name="paddingMask">When this function returns, this is the 32-bit padding mask.</param>
/// <param name="paddingByteCount">When this function returns, this is the number of bytes of to use for a padding block.</param>
public void EncryptData(string path, string encryptedPath, int padding, out uint key, out uint paddingMask, out int paddingByteCount)
{
// 32-bit encryption key
key = MathEx.RandomNumberGenerator.GetUInt32();
// paddingMaskBits is a 32-bit number with a certain number of bits set.
// After each encrypted byte, this mask is rotated right by 1.
// If the least significant bit is 1, a padding is added to the encrypted data stream.
// paddingByteCount is the number of consecutive bytes that are used as padding.
paddingByteCount = 1 + padding / 100;
int paddingMaskBits = padding * 32 / (100 + padding / 100 * 100);
paddingMask = 0;
foreach (int i in Enumerable.Range(0, 32).SortRandom().Take(paddingMaskBits))
{
paddingMask = BitCalculator.SetBit(paddingMask, i, true);
}
uint currentKey = key;
uint currentPaddingMask = paddingMask;
using (FileStream stream = File.OpenRead(path))
using (FileStream encryptedStream = File.Create(encryptedPath))
{
int dataByte;
while ((dataByte = stream.ReadByte()) != -1)
{
// Xor the current byte with the least significant byte of the key.
// Then, key = (key ror 5) * 7
encryptedStream.WriteByte((byte)(dataByte ^ currentKey));
// If the padding mask's least significant bit is 1, add the given number of padding bytes.
// Then, rotate padding mask right by 1.
if ((currentPaddingMask & 1) == 1)
{
for (int j = 0; j < paddingByteCount; j++)
{
encryptedStream.WriteByte(0);
}
}
currentKey = MathEx.Ror(currentKey, 5) * 7;
currentPaddingMask = MathEx.Ror(currentPaddingMask, 1);
}
}
}
public void ShouldReturnTheSumOfGivenBinaryNumbersInDecimal(string numberOne, string numberTwo, int expected)
{
Assert.Equal(expected, BitCalculator.Calculate(numberOne, numberTwo));
}
// GET: Calculator
public ActionResult Index()
{
var viewModel = new BitCalculator();
return(View(viewModel));
}
public ActionResult Index(BitCalculator viewModel)
{
viewModel.CalculateConversions();
return(View(viewModel));
}
