свой ключ для шифрования и дешифрования C# для любого файла

Есть небольшая программа, пишу шифратор и дешифратор для любых файлов. Наткнулся на офф. доки от мелкософта, там алгоритм шифрования и дешифрования только для .txt, а как сделать чтобы можно было любой файл зашифровать (и видео например) чтобы потом оно расшифровалось в таком же расширении или например любая программа чтобы могла расшифроваться?

Вот код шифрования:

private void EncryptFile(string inFile)
{

    // Create instance of Aes for
    // symmetric encryption of the data.
    Aes aes = Aes.Create();
    ICryptoTransform transform = aes.CreateEncryptor();

    // Use RSACryptoServiceProvider to
    // encrypt the AES key.
    // rsa is previously instantiated:
    //    rsa = new RSACryptoServiceProvider(cspp);
    byte[] keyEncrypted = rsa.Encrypt(aes.Key, false);

    // Create byte arrays to contain
    // the length values of the key and IV.
    byte[] LenK = new byte[4];
    byte[] LenIV = new byte[4];

    int lKey = keyEncrypted.Length;
    LenK = BitConverter.GetBytes(lKey);
    int lIV = aes.IV.Length;
    LenIV = BitConverter.GetBytes(lIV);

    // Write the following to the FileStream
    // for the encrypted file (outFs):
    // - length of the key
    // - length of the IV
    // - ecrypted key
    // - the IV
    // - the encrypted cipher content

    int startFileName = inFile.LastIndexOf("\\") + 1;
    // Change the file's extension to ".enc"
    string outFile = EncrFolder + inFile.Substring(startFileName, inFile.LastIndexOf(".") - startFileName) + ".enc";

    using (FileStream outFs = new FileStream(outFile, FileMode.Create))
    {

        outFs.Write(LenK, 0, 4);
        outFs.Write(LenIV, 0, 4);
        outFs.Write(keyEncrypted, 0, lKey);
        outFs.Write(aes.IV, 0, lIV);

        // Now write the cipher text using
        // a CryptoStream for encrypting.
        using (CryptoStream outStreamEncrypted = new CryptoStream(outFs, transform, CryptoStreamMode.Write))
        {

            // By encrypting a chunk at
            // a time, you can save memory
            // and accommodate large files.
            int count = 0;
            int offset = 0;

            // blockSizeBytes can be any arbitrary size.
            int blockSizeBytes = aes.BlockSize / 8;
            byte[] data = new byte[blockSizeBytes];
            int bytesRead = 0;

            using (FileStream inFs = new FileStream(inFile, FileMode.Open))
            {
                do
                {
                    count = inFs.Read(data, 0, blockSizeBytes);
                    offset += count;
                    outStreamEncrypted.Write(data, 0, count);
                    bytesRead += blockSizeBytes;
                }
                while (count > 0);
                inFs.Close();
            }
            outStreamEncrypted.FlushFinalBlock();
            outStreamEncrypted.Close();
        }
        outFs.Close();
    }
}

Вот код дешифратора

private void DecryptFile(string inFile)
{

    // Create instance of Aes for
    // symetric decryption of the data.
    Aes aes = Aes.Create();

    // Create byte arrays to get the length of
    // the encrypted key and IV.
    // These values were stored as 4 bytes each
    // at the beginning of the encrypted package.
    byte[] LenK = new byte[4];
    byte[] LenIV = new byte[4];

    // Construct the file name for the decrypted file.
    string outFile = DecrFolder + inFile.Substring(0, inFile.LastIndexOf(".")) + ".txt";

    // Use FileStream objects to read the encrypted
    // file (inFs) and save the decrypted file (outFs).
    using (FileStream inFs = new FileStream(EncrFolder + inFile, FileMode.Open))
    {

        inFs.Seek(0, SeekOrigin.Begin);
        inFs.Seek(0, SeekOrigin.Begin);
        inFs.Read(LenK, 0, 3);
        inFs.Seek(4, SeekOrigin.Begin);
        inFs.Read(LenIV, 0, 3);

        // Convert the lengths to integer values.
        int lenK = BitConverter.ToInt32(LenK, 0);
        int lenIV = BitConverter.ToInt32(LenIV, 0);

        // Determine the start postition of
        // the ciphter text (startC)
        // and its length(lenC).
        int startC = lenK + lenIV + 8;
        int lenC = (int)inFs.Length - startC;

        // Create the byte arrays for
        // the encrypted Aes key,
        // the IV, and the cipher text.
        byte[] KeyEncrypted = new byte[lenK];
        byte[] IV = new byte[lenIV];

        // Extract the key and IV
        // starting from index 8
        // after the length values.
        inFs.Seek(8, SeekOrigin.Begin);
        inFs.Read(KeyEncrypted, 0, lenK);
        inFs.Seek(8 + lenK, SeekOrigin.Begin);
        inFs.Read(IV, 0, lenIV);
        Directory.CreateDirectory(DecrFolder);
        // Use RSACryptoServiceProvider
        // to decrypt the AES key.
        byte[] KeyDecrypted = rsa.Decrypt(KeyEncrypted, false);

        // Decrypt the key.
        ICryptoTransform transform = aes.CreateDecryptor(KeyDecrypted, IV);

        // Decrypt the cipher text from
        // from the FileSteam of the encrypted
        // file (inFs) into the FileStream
        // for the decrypted file (outFs).
        using (FileStream outFs = new FileStream(outFile, FileMode.Create))
        {

            int count = 0;
            int offset = 0;

            // blockSizeBytes can be any arbitrary size.
            int blockSizeBytes = aes.BlockSize / 8;
            byte[] data = new byte[blockSizeBytes];

            // By decrypting a chunk a time,
            // you can save memory and
            // accommodate large files.

            // Start at the beginning
            // of the cipher text.
            inFs.Seek(startC, SeekOrigin.Begin);
            using (CryptoStream outStreamDecrypted = new CryptoStream(outFs, transform, CryptoStreamMode.Write))
            {
                do
                {
                    count = inFs.Read(data, 0, blockSizeBytes);
                    offset += count;
                    outStreamDecrypted.Write(data, 0, count);
                }
                while (count > 0);

                outStreamDecrypted.FlushFinalBlock();
                outStreamDecrypted.Close();
            }
            outFs.Close();
        }
        inFs.Close();
    }
}