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namespace CryptPower
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        string InputKey = string.Empty;

        private void btn_Start_Click(object sender, EventArgs e)
        {
            Passwort form2 = new Passwort(this);
            form2.ShowDialog();

            if (Rbtn_Encrypt.Checked == true)
            {
                Crypter.EncryptData(textBox1.Text, textBox2.Text, InputKey);
            }

            else if (Rbtn_Decrypt.Checked == true)
            {
                Crypter.DecryptData(textBox1.Text, textBox2.Text, InputKey);
            }

            else
            {
                 MessageBox.Show("Ein Fehler ist aufgetreten! Das Programm wird beendet!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                 Application.Exit();
            }
        }

        private void btn_Search1_Click(object sender, EventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();

            ofd.InitialDirectory = @"C:\";
            ofd.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*";
            ofd.FilterIndex = 2;
            ofd.RestoreDirectory = true;

            if (ofd.ShowDialog() == DialogResult.OK)
            {
                textBox1.Text = ofd.FileName;
            }

            if (textBox1.Text != "" && textBox2.Text != "")
            {
                btn_Start.Enabled = true;
            }
        }

        private void btn_Search2_Click(object sender, EventArgs e)
        {
            FolderBrowserDialog objDialog = new FolderBrowserDialog();
            objDialog.Description = "Speicherort";
            objDialog.SelectedPath = @"C:\";
       
            DialogResult objResult = objDialog.ShowDialog(this);
            if (objResult == DialogResult.OK)
            {
                textBox2.Text = objDialog.SelectedPath;
            }

            if (textBox1.Text != "" && textBox2.Text != "")
            {
                btn_Start.Enabled = true;
            }
        }
 
    }
}                    

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namespace CryptPower
{
    class Crypter
    {
        public static void EncryptData(string sFileIn, string sFileOut, string key)
        {
            FileStream fsIn = new FileStream(sFileIn, FileMode.Open, FileAccess.Read);
            FileStream fsOut = new FileStream(sFileOut, FileMode.Create, FileAccess.Write);

            AesCryptoServiceProvider aes = new AesCryptoServiceProvider();
            aes.Key = ASCIIEncoding.ASCII.GetBytes(key);
            aes.IV = ASCIIEncoding.ASCII.GetBytes(key);

            ICryptoTransform aesEncrypt = aes.CreateEncryptor();
            CryptoStream CrStream = new CryptoStream(fsOut, aesEncrypt, CryptoStreamMode.Write);

            byte[] bytearrayinput = new byte[fsIn.Length - 1];
            fsIn.Read(bytearrayinput, 0, bytearrayinput.Length);
            CrStream.Write(bytearrayinput, 0, bytearrayinput.Length);

        }

        public static void DecryptData(string sFileIn, string sFileOut, string key)
        {
            AesCryptoServiceProvider aes = new AesCryptoServiceProvider();
            
            aes.Key = ASCIIEncoding.ASCII.GetBytes(key);
            aes.IV = ASCIIEncoding.ASCII.GetBytes(key);

            FileStream fsread = new FileStream(sFileIn, FileMode.Open, FileAccess.Read);
            
            ICryptoTransform aesDecrypt = aes.CreateDecryptor();
            CryptoStream CrStream = new CryptoStream(fsread, aesDecrypt, CryptoStreamMode.Read);

            StreamWriter fsDecrypted = new StreamWriter(sFileOut);
            fsDecrypted.Write(new StreamReader(CrStream).ReadToEnd());
            fsDecrypted.Flush();
            fsDecrypted.Close();

        }
    }
}