Encrypt a File Using Rijndael

CryptoManager crm = null;
byte[] cryptoKey = null;
byte[] cryptoIV = null;
string[] line = new string[10];
string pwd = null;
#region Encryption Button
string encName = null;
string origName;
private void btnEnc_Click(object sender, EventArgs e)
{
    try
    {
        DateTime current = DateTime.Now;
        RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
        byte[] keyToEncrypt;
        byte[] encryptedKey;
        origName = txtBrowse.Text;
        encName = origName + ".dat";
        try
        {
            crm.EncryptData(origName, encName, cryptoKey, cryptoIV);
            FileInfo fi = new FileInfo(origName);
            FileInfo fi2 = new FileInfo(encName);
            //remove readonly attribute
            if ((fi.Attributes & FileAttributes.ReadOnly) == FileAttributes.ReadOnly)
            {
                fi.Attributes &= ~FileAttributes.ReadOnly;
            }
            //copy creation and modification time
            fi2.CreationTime = fi.CreationTime;
            fi2.LastWriteTime = fi.LastWriteTime;
            fi2.Attributes = FileAttributes.Normal | FileAttributes.Archive;
            byte[] data = File.ReadAllBytes(encName);
            //delete original file
            File.Delete(encName);
            #region write RSA (Public Private) key in xml files
            StreamWriter writer = new StreamWriter("PublicPrivateKey.xml");
            string publicprivatexml = RSA.ToXmlString(true);
            writer.Write(publicprivatexml);
            writer.Close();
            #endregion
            keyToEncrypt = System.Text.ASCIIEncoding.Unicode.GetBytes(pwd);
            encryptedKey = RSA.Encrypt(keyToEncrypt, false);
            //using (BinaryWriter bw = new BinaryWriter(File.Create(origName + " " + current.Date.Day.ToString() + current.Date.Month.ToString() + current.Date.Year.ToString() + current.TimeOfDay.Duration().Hours.ToString() + current.TimeOfDay.Duration().Minutes.ToString() + current.TimeOfDay.Duration().Seconds.ToString() + ".enc")))
            using (BinaryWriter bw = new BinaryWriter(File.Create(current.Date.Day.ToString() + current.Date.Month.ToString() + current.Date.Year.ToString() + current.TimeOfDay.Duration().Hours.ToString() + current.TimeOfDay.Duration().Minutes.ToString() + current.TimeOfDay.Duration().Seconds.ToString() + ".enc")))
            {
                //Write data
                bw.Seek(0, SeekOrigin.Begin);
                bw.Write(data);
                bw.Write(encryptedKey);
                bw.Close();
            }
            MessageBox.Show("File Encrypted");
        }
        catch (CryptographicException ex)
        {
            MessageBox.Show(ex.Message);
        }
        catch (IOException ex)
        {
            MessageBox.Show(ex.Message);
        }
        catch (UnauthorizedAccessException ex)
        {
            //i.e. readonly
            MessageBox.Show(ex.Message);
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}
#endregion
}

Decryption End

#region Decryption Button
private void btnDnc_Click(object sender, EventArgs e)
{
    try
    {
        DateTime current = DateTime.Now;
        string encName = txtBrowse.Text + "data" + ".enc";
        RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
        #region Seperate key and data
        byte[] alldata = File.ReadAllBytes(txtBrowse.Text);
        byte[] getencryptedkey = new byte[128];
        byte[] data = new byte[alldata.Length - 128];
        for (int i = 0; i < alldata.Length - 128; i++)
        { data[i] = alldata[i]; }
        for (int i = alldata.Length - 128, j = 0; i < alldata.Length; i++, j++)
        { getencryptedkey[j] = alldata[i]; }
        using (BinaryWriter bw = new BinaryWriter(File.Create(encName)))
        {
            bw.Write(data);
            bw.Close();
        }
        #endregion
        #region key decryption
        StreamReader reader = new StreamReader("PublicPrivateKey.xml");
        string publicprivatekeyxml = reader.ReadToEnd();
        RSA.FromXmlString(publicprivatekeyxml);
        reader.Close();
        byte[] decryptedKey = RSA.Decrypt(getencryptedkey, false);
        pwd = System.Text.ASCIIEncoding.Unicode.GetString(decryptedKey);
        byte[] dk = null;
        byte[] div = null;
        crm.getKeysFromPassword(pwd, out dk, out div);
        cryptoKey = dk;
        cryptoIV = div;
        #endregion
        string ext = Path.GetExtension(encName).ToLower();
        if (ext != ".enc")
        {
            MessageBox.Show("Please Enter correct File");
            return;
        }
        string dncName = Path.GetDirectoryName(encName) + "\\" + Path.GetFileNameWithoutExtension(encName);
                dncName = current.Date.Day.ToString() + current.Date.Month.ToString() + current.Date.Year.ToString() + current.TimeOfDay.Duration().Hours.ToString() + current.TimeOfDay.Duration().Minutes.ToString() + current.TimeOfDay.Duration().Seconds.ToString() + ".dnc";
        try
        {
            if (crm.DecryptData(encName, dncName, cryptoKey, cryptoIV))
            {
                FileInfo fi = new FileInfo(encName);
                FileInfo fi2 = new FileInfo(dncName);
                if ((fi.Attributes & FileAttributes.ReadOnly) == FileAttributes.ReadOnly)
                { fi.Attributes &= ~FileAttributes.ReadOnly; }
                //copy creation and modification time
                fi2.CreationTime = fi.CreationTime;
                fi2.LastWriteTime = fi.LastWriteTime;
                //delete encrypted file
                File.Delete(encName);
                MessageBox.Show("File Decrypted");
            }
            else
            {
                 MessageBox.Show("The file can't be decrypted - probably wrong password");
            }
        }
        catch (CryptographicException ex)
        { MessageBox.Show(ex.Message); }
        catch (IOException ex)
        { MessageBox.Show(ex.Message); }
        catch (UnauthorizedAccessException ex)
        { //i.e. readonly
            MessageBox.Show(ex.Message);
        }
    }
    catch (Exception ex)
    { MessageBox.Show(ex.Message); }
}
#endregion 

Random Bases PWD

pwd = "abcdefhz";
//get keys from password
byte[] dk = null;
byte[] div = null;
crm.getKeysFromPassword(pwd, out dk, out div);
cryptoKey = dk;
cryptoIV = div;
}
catch (FormatException ex)
{
MessageBox.Show(ex.Message);
this.Close();
return;
}