public static BlockStream Create(Stream baseStream, Stream wrapper, Action wrapperFlush, CloseOptions closeOption)
{
var block = new BlockStream()
{
_baseStream = baseStream,
_pointerPosition = baseStream.Length,
_wrapperFlush = wrapperFlush,
_closeOption = closeOption,
_wrapper = wrapper
};
baseStream.WriteInt64(0);
return(block);
}
public static BlockStream Read(Stream baseStream, Stream wrapper, Action wrapperFlush, CloseOptions closeOption)
{
var block = new BlockStream()
{
_readMode = true,
_baseStream = baseStream,
_pointerPosition = baseStream.Position,
_wrapperFlush = wrapperFlush,
_closeOption = closeOption,
_wrapper = wrapper,
_blockEndPosition = baseStream.ReadInt64(),
};
block._length = block._blockEndPosition - sizeof(Int64) - block._pointerPosition;
return(block);
}
public static Stream CreateBlock(this Stream baseStream, BlockOptions options, byte[] key, byte[] iv)
{
var compression = options.HasFlag(BlockOptions.Compression);
var encryption = options.HasFlag(BlockOptions.Encryption);
if (compression)
{
if (encryption) //compression & encryption
{
var gzipStream = new GZipStream(baseStream, CompressionLevel.Optimal, true);
var rijAlg = Rijndael.Create();
rijAlg.Key = key;
rijAlg.IV = iv;
var encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);
var encryptionStream = new CryptoStream(gzipStream, encryptor, CryptoStreamMode.Write);
return(BlockStream.Create(baseStream, encryptionStream, () =>
{
encryptionStream.FlushFinalBlock();
gzipStream.Close();
}, CloseOptions.Flush));
}
else //compression
{
var gzipStream = new GZipStream(baseStream, CompressionLevel.Optimal, true);
return(BlockStream.Create(baseStream, gzipStream, null, CloseOptions.Flush | CloseOptions.CloseWrapper));
}
}
else
{
if (encryption) //encryption
{
var rijAlg = Rijndael.Create();
rijAlg.Key = key;
rijAlg.IV = iv;
var encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);
var encryptionStream = new CryptoStream(baseStream, encryptor, CryptoStreamMode.Write);
return(BlockStream.Create(baseStream, encryptionStream, () =>
{
encryptionStream.FlushFinalBlock();
}, CloseOptions.Flush));
}
else
{
throw new ArgumentOutOfRangeException();
}
}
}
