public static void EncryptToFile(string filePath, Stream input, int chunkSize, byte[] key, byte[] iv)
{
// Make sure the input stream is at the beginning
input.Seek(0, SeekOrigin.Begin);
AesCounterStream cryptoStream = new AesCounterStream(input, true, key, iv);
using (FileStream fileStream = new FileStream(filePath, FileMode.Create, FileAccess.Write))
{
int curByte = 0;
int processedBytes = 0;
byte[] buffer = new byte[chunkSize];
int bytesRemaining = (int)input.Length;
int bytesToRead = chunkSize;
do
{
if (chunkSize > bytesRemaining)
{
bytesToRead = bytesRemaining;
}
processedBytes = cryptoStream.Read(buffer, 0, bytesToRead);
if (processedBytes > 0)
{
fileStream.Write(buffer, 0, processedBytes);
// Clear the buffer
Array.Clear(buffer, 0, chunkSize);
}
curByte += processedBytes;
bytesRemaining -= processedBytes;
}while (processedBytes > 0 && bytesRemaining > 0);
}
}
public static byte[] ProcessCipher(bool encrypt, Stream input, int chunkSize, byte[] key, byte[] iv)
{
// Make sure the input stream is at the beginning
input.Seek(0, SeekOrigin.Begin);
AesCounterStream cryptoStream = new AesCounterStream(input, encrypt, key, iv);
// Initialize variables
byte[] output = new byte[input.Length];
// Process the stream and save the bytes to the output
int curByte = 0;
int processedBytes = 0;
byte[] buffer = new byte[chunkSize];
int bytesRemaining = (int)input.Length;
int bytesToRead = chunkSize;
do
{
if (chunkSize > bytesRemaining)
{
bytesToRead = bytesRemaining;
}
processedBytes = cryptoStream.Read(buffer, 0, bytesToRead);
if (processedBytes > 0)
{
buffer.Take(processedBytes).ToArray().CopyTo(output, curByte);
// Clear the buffer
Array.Clear(buffer, 0, chunkSize);
}
curByte += processedBytes;
bytesRemaining -= processedBytes;
}while (processedBytes > 0 && bytesRemaining > 0);
return(output);
}
