void CompareOutput(IPadding Padding)
{
CSPPrng rng = new CSPPrng();
byte[] fill = new byte[16];
rng.GetBytes(fill);
const int BLOCK = 16;
for (int i = 0; i < BLOCK; i++)
{
byte[] data = new byte[BLOCK];
// fill with rand
if (i > 0)
{
Array.Copy(fill, data, BLOCK - i);
}
// pad array
Padding.AddPadding(data, i);
// verify length
int len = Padding.GetPaddingLength(data);
if (len == 0 && i != 0)
{
throw new Exception("PaddingTest: Failed the padding value return check!");
}
else if (i != 0 && len != BLOCK - i)
{
throw new Exception("PaddingTest: Failed the padding value return check!");
}
// test offset method
if (i > 0 && i < 15)
{
len = Padding.GetPaddingLength(data, i);
if (len == 0 && i != 0)
{
throw new Exception("PaddingTest: Failed the padding value return check!");
}
else if (i != 0 && len != BLOCK - i)
{
throw new Exception("PaddingTest: Failed the padding value return check!");
}
}
}
rng.Dispose();
}
private void BlockDecrypt(ICipherMode Cipher, IPadding Padding, byte[] Input, int InOffset, ref byte[] Output, int OutOffset)
{
int blkSize = Cipher.BlockSize;
long inpSize = (Input.Length - InOffset);
long alnSize = inpSize - blkSize;
long count = 0;
Cipher.IsParallel = false;
while (count != alnSize)
{
Cipher.Transform(Input, InOffset, Output, OutOffset);
InOffset += blkSize;
OutOffset += blkSize;
count += blkSize;
}
// last block
byte[] inpBuffer = new byte[blkSize];
Buffer.BlockCopy(Input, InOffset, inpBuffer, 0, blkSize);
byte[] outBuffer = new byte[blkSize];
Cipher.Transform(inpBuffer, 0, outBuffer, 0);
int fnlSize = blkSize - Padding.GetPaddingLength(outBuffer, 0);
Buffer.BlockCopy(outBuffer, 0, Output, OutOffset, fnlSize);
OutOffset += fnlSize;
if (Output.Length != OutOffset)
{
Array.Resize(ref Output, OutOffset);
}
}
private void DecryptFile(string InputPath, string OutputPath)
{
using (BinaryReader inputReader = new BinaryReader(new FileStream(InputPath, FileMode.Open, FileAccess.Read, FileShare.None)))
{
byte[] inputBuffer = new byte[this.BlockSize];
byte[] outputBuffer = new byte[this.BlockSize];
long bytesRead = 0;
long bytesTotal = 0;
// move past header
inputReader.BaseStream.Position = MessageHeader.GetHeaderSize;
using (BinaryWriter outputWriter = new BinaryWriter(new FileStream(OutputPath, FileMode.Create, FileAccess.Write, FileShare.None)))
{
int maxOut = (int)inputReader.BaseStream.Length - MessageHeader.GetHeaderSize;
while ((bytesRead = inputReader.Read(inputBuffer, 0, this.BlockSize)) > 0)
{
bytesTotal += bytesRead;
if (bytesTotal < maxOut)
{
this.Mode.Transform(inputBuffer, outputBuffer);
outputWriter.Write(outputBuffer);
if (bytesTotal % this.ProgressInterval == 0)
{
CalculateProgress(bytesTotal);
}
}
else
{
this.Mode.Transform(inputBuffer, outputBuffer);
int size = this.BlockSize - Padding.GetPaddingLength(outputBuffer);
outputWriter.Write(outputBuffer, 0, size);
CalculateProgress(bytesTotal + size);
}
}
}
}
}