Is there a .NET encryption library that implements AES 256 encryption as a Stream?

Question

I'd like to be able to encrypt / decrypt data as it's streamed to/from disk. I know I could write my own Stream and implement the encryption there, but I'd rather not risk doing it wrong. Is there a library that works in a similar way to the following code?

byte[] encryptionKey = ;
byte[] initVector = ;

var fileStream = new FileStream(filePath, FileMode.CreateNew, FileAccess.Write);
var encryptionStream = new AesEncryptionStream(fileStream, initVector, encryptionKey);
var gzStream = new GZipStream(encryptionStream, CompressionMode.Compress);
var writer = new BinaryWriter(gzStream);

Answer 1

You're looking for the RijndaelManaged and CryptoStream classes:

var aes = new RijndaelManaged { Key = ..., IV = ... };

using (var encryptor = aes.CreateEncryptor()) 
using (var cryptoStream = new CryptoStream(gzStream, encryptor, CryptoStreamMode.Write))
using (var writer = new BinaryWriter(cryptoStream)) {
    ...
}