Чщк

        private void button1_Click(object sender, EventArgs e)
        {
            Stream input = null;
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                if ((input = openFileDialog1.OpenFile()) != null)
                {
                    int p = 0;
                    byte[] mass = File.ReadAllBytes(openFileDialog1.FileName);
                    string rass = openFileDialog1.FileName.Substring(openFileDialog1.FileName.Length - 3);
                    byte[] rasb = encode.GetBytes(rass);
                    byte[] key = encode.GetBytes(textBox1.Text);
                    byte[] fullkey = new byte[mass.Length];
                    for (int i = 0; i < fullkey.Length; i++)
                    {
                        fullkey[i] = key[p];
                        p++;
                        if (p == key.Length)
                            p = 0;
                    }
                    for (int i = 0; i < fullkey.Length; i++)
                    {
                        mass[i] = (byte)(mass[i] ^ fullkey[i]);
                    }
                    byte[] exemass = File.ReadAllBytes(Application.ExecutablePath);
                    byte[] final = new byte[exemass.Length + mass.Length+3];
                    for (int i = 0; i < exemass.Length; i++)
                    {
                        final[i] = exemass[i];
                    }
                    int k=0;
                    for (int j = exemass.Length; j < exemass.Length + mass.Length; j++)
                    {
                        final[j] = mass[k];
                        k++;
                    }
                    int l = 0;
                    for (int m = exemass.Length + mass.Length; m < exemass.Length + mass.Length + 3; m++)
                    {
                        final[m] = rasb[l];
                        l++;
                    }
                    File.WriteAllBytes(Application.StartupPath + "/Crypted.exe", final);
                    MessageBox.Show("Success!");
                }
            }
        }

        private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (!Char.IsDigit(e.KeyChar))
            {
                e.Handled = true;
            }
            button1.Enabled = true;
            byte[] exemass = File.ReadAllBytes(Application.ExecutablePath);
            if (exemass.Length > 11264)
                button2.Enabled = true;
        }

        private void button2_Click(object sender, EventArgs e)
        {
            byte[] cryptedexe = File.ReadAllBytes(Application.ExecutablePath);
            byte[] dividedfile = new byte[cryptedexe.Length - 11267];
            byte[] rasb = new byte[3];
            int h=0;
            int p = 0;
            int g = 0;
            for (int i = 11264; i < cryptedexe.Length; i++)
            {
                if (i < (cryptedexe.Length - 3))
                {
                    dividedfile[h] = cryptedexe[i];
                    h++;
                }
                else
                {
                    rasb[g] = cryptedexe[i];
                    g++;
                }
            }
            string rass = encode.GetString(rasb);
            byte[] key = encode.GetBytes(textBox1.Text);
            byte[] fullkey = new byte[dividedfile.Length];
            for (int i = 0; i < fullkey.Length; i++)
            {
                fullkey[i] = key[p];
                p++;
                if (p == key.Length)
                    p = 0;
            }
            for (int i = 0; i < fullkey.Length; i++)
            {
                dividedfile[i] = (byte)(dividedfile[i] ^ fullkey[i]);
            }
            File.WriteAllBytes(Application.StartupPath + "/decrypted."+rass, dividedfile);
        }