private void button4_Click(object sender, EventArgs e)
        {
            bool isEqual = false;

            string signature = textBox5.Text;
            string pub       = textBox1.Text;
            string pri       = textBox2.Text;

            if (pub.Equals("") || pri.Equals(""))
            {
                MessageBox.Show("Виберіть шляхи до ключів");
                return;
            }

            if (radioButton1.Checked)
            {
                string text = textBox3.Text;
                using (var stream = GenerateStreamFromString(text))
                {
                    using (var myDssUnit = new DssUnit()) // for deletting all data after creating key pair
                    {
                        if (myDssUnit.OpenKeyPair(pub, pri))
                        {
                            if (myDssUnit.OpenKeyPair(pub, pri))
                            {
                                isEqual = myDssUnit.VerifySignature(stream, signature);
                            }
                        }
                    }
                    stream.Close();
                }
            }
            else
            {
                string filePath = textBox4.Text;
                using (var fs = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read))
                {
                    using (var myDssUnit = new DssUnit()) // for deletting all data after creating key pair
                    {
                        if (myDssUnit.OpenKeyPair(pub, pri))
                        {
                            isEqual = myDssUnit.VerifySignature(fs, signature);
                        }
                    }
                    fs.Close();
                }
            }
            if (isEqual)
            {
                MessageBox.Show("Підписи співпадають");
            }
            else
            {
                MessageBox.Show("Підписи не співпадають");
            }
            //textBox5.Text = signature;
        }
        private void button4_Click(object sender, EventArgs e)
        {
            bool isEqual = false;

            string signature = textBox5.Text;
            string pub = textBox1.Text;
            string pri = textBox2.Text;
            if (pub.Equals("") || pri.Equals(""))
            {
                MessageBox.Show("Виберіть шляхи до ключів");
                return;
            }

            if (radioButton1.Checked)
            {
                string text = textBox3.Text;
                using (var stream = GenerateStreamFromString(text))
                {
                    using (var myDssUnit = new DssUnit()) // for deletting all data after creating key pair
                    {
                        if (myDssUnit.OpenKeyPair(pub, pri))
                        {
                            if (myDssUnit.OpenKeyPair(pub, pri))
                            {
                                isEqual = myDssUnit.VerifySignature(stream, signature);
                            }
                        }
                    }
                    stream.Close();
                }
            }
            else
            {
                string filePath = textBox4.Text;
                using (var fs = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read))
                {
                    using (var myDssUnit = new DssUnit()) // for deletting all data after creating key pair
                    {
                        if (myDssUnit.OpenKeyPair(pub, pri))
                        {
                            isEqual = myDssUnit.VerifySignature(fs, signature);
                        }
                    }
                    fs.Close();
                }
            }
            if (isEqual)
                MessageBox.Show("Підписи співпадають");
            else
                MessageBox.Show("Підписи не співпадають");
                //textBox5.Text = signature;
        }