public void DecryptFile(string inFileName, string outFileName, long splitSize, SplitFileMode mode)
{
Contract.Requires(splitSize > 0L);
base.CheckDisposed();
long i = 1, fileLength;
while (File.Exists(String.Concat(inFileName, "_Part", i, ".temp")))
{
i++;
}
FileStream lastInFileStream = new FileStream(String.Concat(inFileName, "_Part", --i, ".temp"), FileMode.Open, FileAccess.ReadWrite);
long lastInStreamLength = lastInFileStream.Length - 8;
lastInFileStream.Position = lastInStreamLength;
using (var reader = new BinaryReader(lastInFileStream))
{
fileLength = reader.ReadInt64();
}
lastInFileStream.Position = 0L;
lastInFileStream.SetLength(lastInStreamLength);
long oddSize, avgSize = Math.DivRem(fileLength, splitSize, out oddSize),
count, size;
i = 0L;
switch (mode)
{
case SplitFileMode.InputFileLength:
count = avgSize;
size = splitSize;
break;
default:
count = splitSize;
size = avgSize;
break;
}
using (ICryptoTransform decrypto = _rijndael.CreateDecryptor(_legalKey, _legalIV))
using (CryptoStream outStream = new CryptoStream(new FileStream(outFileName, FileMode.Create, FileAccess.Write), decrypto, CryptoStreamMode.Write))
{
while (i < count)
{
long length = (++i) == count ? size + oddSize : size;
using (FileStream inStream = i == count ? lastInFileStream : new FileStream(String.Concat(inFileName, "_Part", i, ".temp"), FileMode.Open, FileAccess.Read))
{
inStream.FixedCopyTo(outStream, length);
if (i == count)
{
inStream.FixedCopyTo(outStream);
}
}
}
}
}
public void EncryptFile(string inFileName, string outFileName, long splitSize, SplitFileMode mode)
{
Contract.Requires(splitSize > 0L);
base.CheckDisposed();
FileStream inFileStream = new FileStream(inFileName, FileMode.Open, FileAccess.Read);
long fileLength = inFileStream.Length, oddSize, avgSize = Math.DivRem(fileLength, splitSize, out oddSize),
i = 0L, count, size;
switch (mode)
{
case SplitFileMode.InputFileLength:
count = avgSize;
size = splitSize;
break;
default:
count = splitSize;
size = avgSize;
break;
}
using (ICryptoTransform encrypto = _rijndael.CreateEncryptor(_legalKey, _legalIV))
using (CryptoStream inStream = new CryptoStream(inFileStream, encrypto, CryptoStreamMode.Read))
{
while (i < count)
{
long length = (++i) == count ? size + oddSize : size;
using (FileStream outStream = new FileStream(String.Concat(outFileName, "_Part", i, ".temp"), FileMode.Create, FileAccess.Write))
{
inStream.FixedCopyTo(outStream, length);
if (i == count)
{
inStream.FixedCopyTo(outStream);
using (var writer = new BinaryWriter(outStream))
{
writer.Write(fileLength);
}
}
}
}
}
}
