public byte[] Decrypt(byte[] data)
{
// Clone the key so that we don't modify it
byte[] key = (byte[])CurrentKey.Clone();
// Get the actual data length
int dataLength = data.Length - 1;
// Security check (padded correctly?)
if (dataLength % key.Length != 0)
{
return(new byte[0]);
}
// Make a new array to build our return value
byte[] returnVal = new byte[data.Length];
returnVal[0] = data[0];
// Go through the data
int z = 1;
for (int i = 0; i < (dataLength / key.Length); i++)
{
for (int x = 0; x < key.Length; x++)
{
returnVal[z] = (byte)(data[z] ^ key[x]);
key[x] = data[z++];
}
}
// Skip the padding bytes
byte padding = returnVal[0];
return(returnVal.Skip(1 + padding).ToArray());
}
public byte[] Encrypt(byte[] data)
{
// Clone the key so that we don't modify it
byte[] key = (byte[])CurrentKey.Clone();
// Work out how much padding needs to be done
int wholeIterations = data.Length / key.Length;
byte padding = (byte)((key.Length * (wholeIterations + 1)) - data.Length);
if (padding > 0)
{
wholeIterations++;
}
// Create a new array for our return value
byte[] returnVal = new byte[data.Length + padding + 1];
returnVal[0] = padding;
// Add the padding bytes
Random rnd = new Random();
for (int y = 0; y < padding; y++)
{
returnVal[y + 1] = (byte)rnd.Next(0, 255);
}
// Add the data
Array.Copy(data, 0, returnVal, padding + 1, data.Length);
// Encrypt the data and padding bytes
int z = 1;
for (int i = 0; i < wholeIterations; i++)
{
for (int x = 0; x < key.Length; x++)
{
returnVal[z] ^= key[x];
key[x] = returnVal[z++];
}
}
return(returnVal);
}
