/*
 * SecureBlackbox 2024 .NET Edition - Sample Project
 *
 * This sample project demonstrates the usage of SecureBlackbox in a 
 * simple, straightforward way. It is not intended to be a complete 
 * application. Error handling and other checks are simplified for clarity.
 *
 * www.nsoftware.com/secureblackbox
 *
 * This code is subject to the terms and conditions specified in the 
 * corresponding product license agreement which outlines the authorized 
 * usage and restrictions.
 * 
 */

using System;
using System.Windows.Forms;
using nsoftware.SecureBlackbox;

namespace SignDetached
{
	/// <summary>
	/// Summary description for Form1.
	/// </summary>
	public class frmMainForm : System.Windows.Forms.Form
	{
		internal System.Windows.Forms.GroupBox gbSettings;
		internal System.Windows.Forms.Label lblInputEncoding;
		internal System.Windows.Forms.ComboBox comboEncoding;
		internal System.Windows.Forms.Button btnBrowseInputFile;
		internal System.Windows.Forms.TextBox tbInputFile;
		internal System.Windows.Forms.Label lblInputFilename;
		internal System.Windows.Forms.TextBox tbSignatureFile;
		internal System.Windows.Forms.Label lblSignatureFilename;
		internal System.Windows.Forms.Button btnBrowseOutputFile;
		internal System.Windows.Forms.ComboBox comboKeyAlg;
		internal System.Windows.Forms.Label lblKeyAlg;
		internal System.Windows.Forms.Button btnBrowseKeyFile;
		internal System.Windows.Forms.Label lblPassword;
		internal System.Windows.Forms.TextBox tbKeyFile;
		internal System.Windows.Forms.TextBox tbPassphrase;
		internal System.Windows.Forms.Label lblKeyFilename;
		internal System.Windows.Forms.Button btnGo;
		internal System.Windows.Forms.OpenFileDialog dlgOpenKeyFile;
		internal System.Windows.Forms.OpenFileDialog dlgOpenFile;
		internal System.Windows.Forms.SaveFileDialog dlgSaveFile;
		private System.Windows.Forms.Label lblKeyContainerType;
		private System.Windows.Forms.ComboBox comboKeyContainerType;
        private RadioButton rbVerify;
        private RadioButton rbSign;
        private Label label9;
        internal ComboBox comboCurve;
        internal Label lblCurve;

        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.Container components = null;

		public frmMainForm()
		{
			//
			// Required for Windows Form Designer support
			//
			InitializeComponent();

			//
			// TODO: Add any constructor code after InitializeComponent call
			//
		}

		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
            this.btnGo = new System.Windows.Forms.Button();
            this.gbSettings = new System.Windows.Forms.GroupBox();
            this.comboCurve = new System.Windows.Forms.ComboBox();
            this.lblCurve = new System.Windows.Forms.Label();
            this.rbVerify = new System.Windows.Forms.RadioButton();
            this.rbSign = new System.Windows.Forms.RadioButton();
            this.comboKeyContainerType = new System.Windows.Forms.ComboBox();
            this.lblKeyContainerType = new System.Windows.Forms.Label();
            this.lblInputEncoding = new System.Windows.Forms.Label();
            this.comboEncoding = new System.Windows.Forms.ComboBox();
            this.btnBrowseInputFile = new System.Windows.Forms.Button();
            this.tbInputFile = new System.Windows.Forms.TextBox();
            this.lblInputFilename = new System.Windows.Forms.Label();
            this.tbSignatureFile = new System.Windows.Forms.TextBox();
            this.lblSignatureFilename = new System.Windows.Forms.Label();
            this.btnBrowseOutputFile = new System.Windows.Forms.Button();
            this.comboKeyAlg = new System.Windows.Forms.ComboBox();
            this.lblKeyAlg = new System.Windows.Forms.Label();
            this.btnBrowseKeyFile = new System.Windows.Forms.Button();
            this.lblPassword = new System.Windows.Forms.Label();
            this.tbKeyFile = new System.Windows.Forms.TextBox();
            this.tbPassphrase = new System.Windows.Forms.TextBox();
            this.lblKeyFilename = new System.Windows.Forms.Label();
            this.dlgOpenKeyFile = new System.Windows.Forms.OpenFileDialog();
            this.dlgOpenFile = new System.Windows.Forms.OpenFileDialog();
            this.dlgSaveFile = new System.Windows.Forms.SaveFileDialog();
            this.label9 = new System.Windows.Forms.Label();
            this.gbSettings.SuspendLayout();
            this.SuspendLayout();
            // 
            // btnGo
            // 
            this.btnGo.Location = new System.Drawing.Point(378, 403);
            this.btnGo.Name = "btnGo";
            this.btnGo.Size = new System.Drawing.Size(70, 25);
            this.btnGo.TabIndex = 4;
            this.btnGo.Text = "Sign";
            this.btnGo.Click += new System.EventHandler(this.btnGo_Click);
            // 
            // gbSettings
            // 
            this.gbSettings.Controls.Add(this.comboCurve);
            this.gbSettings.Controls.Add(this.lblCurve);
            this.gbSettings.Controls.Add(this.rbVerify);
            this.gbSettings.Controls.Add(this.rbSign);
            this.gbSettings.Controls.Add(this.comboKeyContainerType);
            this.gbSettings.Controls.Add(this.lblKeyContainerType);
            this.gbSettings.Controls.Add(this.lblInputEncoding);
            this.gbSettings.Controls.Add(this.comboEncoding);
            this.gbSettings.Controls.Add(this.btnBrowseInputFile);
            this.gbSettings.Controls.Add(this.tbInputFile);
            this.gbSettings.Controls.Add(this.lblInputFilename);
            this.gbSettings.Controls.Add(this.tbSignatureFile);
            this.gbSettings.Controls.Add(this.lblSignatureFilename);
            this.gbSettings.Controls.Add(this.btnBrowseOutputFile);
            this.gbSettings.Controls.Add(this.comboKeyAlg);
            this.gbSettings.Controls.Add(this.lblKeyAlg);
            this.gbSettings.Controls.Add(this.btnBrowseKeyFile);
            this.gbSettings.Controls.Add(this.lblPassword);
            this.gbSettings.Controls.Add(this.tbKeyFile);
            this.gbSettings.Controls.Add(this.tbPassphrase);
            this.gbSettings.Controls.Add(this.lblKeyFilename);
            this.gbSettings.Location = new System.Drawing.Point(8, 34);
            this.gbSettings.Name = "gbSettings";
            this.gbSettings.Size = new System.Drawing.Size(440, 361);
            this.gbSettings.TabIndex = 3;
            this.gbSettings.TabStop = false;
            this.gbSettings.Text = "Settings";
            // 
            // comboCurve
            // 
            this.comboCurve.DisplayMember = "0";
            this.comboCurve.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
            this.comboCurve.ItemHeight = 13;
            this.comboCurve.Items.AddRange(new object[] {
            "",
            "SECP112R1",
            "SECT113R1",
            "SECP128R1",
            "SECT131R1",
            "SECP160K1",
            "SECT163K1",
            "C2PNB176W1",
            "C2TNB191V1",
            "SECP192K1",
            "SECT193R1",
            "C2PNB208W1",
            "SECP224K1",
            "SECT233K1",
            "SECT239K1",
            "SECP256K1",
            "C2PNB272W1",
            "SECT283K1",
            "C2PNB304W1",
            "C2TNB359V1",
            "C2PNB368W1",
            "SECP384R1",
            "SECT409K1",
            "C2TNB431R1",
            "BRAINPOOLP512R1",
            "SECP521R1",
            "SECT571K1"});
            this.comboCurve.Location = new System.Drawing.Point(312, 224);
            this.comboCurve.Name = "comboCurve";
            this.comboCurve.Size = new System.Drawing.Size(92, 21);
            this.comboCurve.TabIndex = 16;
            // 
            // lblCurve
            // 
            this.lblCurve.AutoSize = true;
            this.lblCurve.Location = new System.Drawing.Point(312, 208);
            this.lblCurve.Name = "lblCurve";
            this.lblCurve.Size = new System.Drawing.Size(54, 13);
            this.lblCurve.TabIndex = 17;
            this.lblCurve.Text = "EC curve:";
            // 
            // rbVerify
            // 
            this.rbVerify.AutoSize = true;
            this.rbVerify.Location = new System.Drawing.Point(105, 25);
            this.rbVerify.Name = "rbVerify";
            this.rbVerify.Size = new System.Drawing.Size(53, 17);
            this.rbVerify.TabIndex = 15;
            this.rbVerify.Text = "Verify";
            this.rbVerify.UseVisualStyleBackColor = true;
            this.rbVerify.CheckedChanged += new System.EventHandler(this.rbSign_CheckedChanged);
            // 
            // rbSign
            // 
            this.rbSign.AutoSize = true;
            this.rbSign.Checked = true;
            this.rbSign.Location = new System.Drawing.Point(16, 25);
            this.rbSign.Name = "rbSign";
            this.rbSign.Size = new System.Drawing.Size(45, 17);
            this.rbSign.TabIndex = 14;
            this.rbSign.TabStop = true;
            this.rbSign.Text = "Sign";
            this.rbSign.UseVisualStyleBackColor = true;
            this.rbSign.CheckedChanged += new System.EventHandler(this.rbSign_CheckedChanged);
            // 
            // comboKeyContainerType
            // 
            this.comboKeyContainerType.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
            this.comboKeyContainerType.Items.AddRange(new object[] {
            "Generic private key",
            "X.509 certificate"});
            this.comboKeyContainerType.Location = new System.Drawing.Point(16, 224);
            this.comboKeyContainerType.Name = "comboKeyContainerType";
            this.comboKeyContainerType.Size = new System.Drawing.Size(142, 21);
            this.comboKeyContainerType.TabIndex = 13;
            this.comboKeyContainerType.SelectedIndexChanged += new System.EventHandler(this.comboKeyContainerType_SelectedIndexChanged);
            // 
            // lblKeyContainerType
            // 
            this.lblKeyContainerType.AutoSize = true;
            this.lblKeyContainerType.Location = new System.Drawing.Point(16, 208);
            this.lblKeyContainerType.Name = "lblKeyContainerType";
            this.lblKeyContainerType.Size = new System.Drawing.Size(102, 13);
            this.lblKeyContainerType.TabIndex = 12;
            this.lblKeyContainerType.Text = "Key container type:";
            // 
            // lblInputEncoding
            // 
            this.lblInputEncoding.AutoSize = true;
            this.lblInputEncoding.Location = new System.Drawing.Point(16, 157);
            this.lblInputEncoding.Name = "lblInputEncoding";
            this.lblInputEncoding.Size = new System.Drawing.Size(54, 13);
            this.lblInputEncoding.TabIndex = 6;
            this.lblInputEncoding.Text = "Encoding:";
            // 
            // comboEncoding
            // 
            this.comboEncoding.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
            this.comboEncoding.ItemHeight = 13;
            this.comboEncoding.Items.AddRange(new object[] {
            "Binary",
            "Base64",
            "Compact",
            "JSON"});
            this.comboEncoding.Location = new System.Drawing.Point(16, 175);
            this.comboEncoding.Name = "comboEncoding";
            this.comboEncoding.Size = new System.Drawing.Size(88, 21);
            this.comboEncoding.TabIndex = 5;
            // 
            // btnBrowseInputFile
            // 
            this.btnBrowseInputFile.Location = new System.Drawing.Point(360, 68);
            this.btnBrowseInputFile.Name = "btnBrowseInputFile";
            this.btnBrowseInputFile.Size = new System.Drawing.Size(70, 25);
            this.btnBrowseInputFile.TabIndex = 1;
            this.btnBrowseInputFile.Text = "Browse ...";
            this.btnBrowseInputFile.Click += new System.EventHandler(this.btnBrowseInputFile_Click);
            // 
            // tbInputFile
            // 
            this.tbInputFile.Location = new System.Drawing.Point(16, 71);
            this.tbInputFile.Name = "tbInputFile";
            this.tbInputFile.Size = new System.Drawing.Size(336, 21);
            this.tbInputFile.TabIndex = 0;
            // 
            // lblInputFilename
            // 
            this.lblInputFilename.Location = new System.Drawing.Point(16, 55);
            this.lblInputFilename.Name = "lblInputFilename";
            this.lblInputFilename.Size = new System.Drawing.Size(112, 16);
            this.lblInputFilename.TabIndex = 1;
            this.lblInputFilename.Text = "Input filename:";
            // 
            // tbSignatureFile
            // 
            this.tbSignatureFile.Location = new System.Drawing.Point(16, 119);
            this.tbSignatureFile.Name = "tbSignatureFile";
            this.tbSignatureFile.Size = new System.Drawing.Size(336, 21);
            this.tbSignatureFile.TabIndex = 2;
            // 
            // lblSignatureFilename
            // 
            this.lblSignatureFilename.Location = new System.Drawing.Point(16, 103);
            this.lblSignatureFilename.Name = "lblSignatureFilename";
            this.lblSignatureFilename.Size = new System.Drawing.Size(112, 16);
            this.lblSignatureFilename.TabIndex = 1;
            this.lblSignatureFilename.Text = "Output filename:";
            // 
            // btnBrowseOutputFile
            // 
            this.btnBrowseOutputFile.Location = new System.Drawing.Point(360, 116);
            this.btnBrowseOutputFile.Name = "btnBrowseOutputFile";
            this.btnBrowseOutputFile.Size = new System.Drawing.Size(70, 25);
            this.btnBrowseOutputFile.TabIndex = 3;
            this.btnBrowseOutputFile.Text = "Browse ...";
            this.btnBrowseOutputFile.Click += new System.EventHandler(this.btnBrowseOutputFile_Click);
            // 
            // comboKeyAlg
            // 
            this.comboKeyAlg.DisplayMember = "0";
            this.comboKeyAlg.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
            this.comboKeyAlg.ItemHeight = 13;
            this.comboKeyAlg.Items.AddRange(new object[] {
            "",
            "RSA",
            "DSA",
            "EC",
            "ECDSA",
            "DH",
            "EDDSA"});
            this.comboKeyAlg.Location = new System.Drawing.Point(179, 224);
            this.comboKeyAlg.Name = "comboKeyAlg";
            this.comboKeyAlg.Size = new System.Drawing.Size(104, 21);
            this.comboKeyAlg.TabIndex = 4;
            this.comboKeyAlg.SelectedIndexChanged += new System.EventHandler(this.comboKeyAlg_SelectedIndexChanged);
            // 
            // lblKeyAlg
            // 
            this.lblKeyAlg.AutoSize = true;
            this.lblKeyAlg.Location = new System.Drawing.Point(179, 208);
            this.lblKeyAlg.Name = "lblKeyAlg";
            this.lblKeyAlg.Size = new System.Drawing.Size(76, 13);
            this.lblKeyAlg.TabIndex = 11;
            this.lblKeyAlg.Text = "Key algorithm:";
            // 
            // btnBrowseKeyFile
            // 
            this.btnBrowseKeyFile.Location = new System.Drawing.Point(360, 265);
            this.btnBrowseKeyFile.Name = "btnBrowseKeyFile";
            this.btnBrowseKeyFile.Size = new System.Drawing.Size(70, 25);
            this.btnBrowseKeyFile.TabIndex = 8;
            this.btnBrowseKeyFile.Text = "Browse ...";
            this.btnBrowseKeyFile.Click += new System.EventHandler(this.btnBrowseKeyFile_Click);
            // 
            // lblPassword
            // 
            this.lblPassword.Location = new System.Drawing.Point(16, 300);
            this.lblPassword.Name = "lblPassword";
            this.lblPassword.Size = new System.Drawing.Size(100, 16);
            this.lblPassword.TabIndex = 1;
            this.lblPassword.Text = "Password:";
            // 
            // tbKeyFile
            // 
            this.tbKeyFile.Location = new System.Drawing.Point(16, 268);
            this.tbKeyFile.Name = "tbKeyFile";
            this.tbKeyFile.Size = new System.Drawing.Size(336, 21);
            this.tbKeyFile.TabIndex = 7;
            // 
            // tbPassphrase
            // 
            this.tbPassphrase.Location = new System.Drawing.Point(16, 316);
            this.tbPassphrase.Name = "tbPassphrase";
            this.tbPassphrase.PasswordChar = '*';
            this.tbPassphrase.Size = new System.Drawing.Size(144, 21);
            this.tbPassphrase.TabIndex = 10;
            // 
            // lblKeyFilename
            // 
            this.lblKeyFilename.Location = new System.Drawing.Point(16, 252);
            this.lblKeyFilename.Name = "lblKeyFilename";
            this.lblKeyFilename.Size = new System.Drawing.Size(176, 16);
            this.lblKeyFilename.TabIndex = 0;
            this.lblKeyFilename.Text = "Private key container file:";
            // 
            // dlgOpenKeyFile
            // 
            this.dlgOpenKeyFile.Filter = "All key and certificate files (*.*)|*.*";
            // 
            // label9
            // 
            this.label9.ForeColor = System.Drawing.SystemColors.Highlight;
            this.label9.Location = new System.Drawing.Point(5, 9);
            this.label9.Name = "label9";
            this.label9.Size = new System.Drawing.Size(383, 16);
            this.label9.TabIndex = 55;
            this.label9.Text = "This sample shows how to detached sign and verify signature.";
            // 
            // frmMainForm
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 14);
            this.ClientSize = new System.Drawing.Size(458, 436);
            this.Controls.Add(this.label9);
            this.Controls.Add(this.btnGo);
            this.Controls.Add(this.gbSettings);
            this.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(204)));
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
            this.MaximizeBox = false;
            this.Name = "frmMainForm";
            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
            this.Text = "Public key crypto Demo";
            this.Load += new System.EventHandler(this.frmMainForm_Load);
            this.gbSettings.ResumeLayout(false);
            this.gbSettings.PerformLayout();
            this.ResumeLayout(false);

		}
		#endregion

		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main()
        {
            Application.Run(new frmMainForm());
        }

        private void DoPasswordNeeded(object sender, CryptoKeyManagerPasswordNeededEventArgs e)
        {
            e.Password = tbPassphrase.Text;
            e.Cancel = false;
        }

        private void LoadKeyFromFile(PublicKeyCrypto crypto)
        {
            CryptoKeyManager keymanager = new CryptoKeyManager();

            keymanager.OnPasswordNeeded += new CryptoKeyManager.OnPasswordNeededHandler(DoPasswordNeeded);

            if (comboKeyContainerType.SelectedIndex == 1)
            {
                CertificateManager certmanager = new CertificateManager();

                certmanager.ImportFromFile(tbKeyFile.Text, tbPassphrase.Text);

                keymanager.Certificate = certmanager.Certificate;
                keymanager.ImportFromCert();

                crypto.Key = keymanager.Key;
            }
            else
            {
                keymanager.ImportFromFile(tbKeyFile.Text,  1, comboKeyAlg.Text, comboCurve.Text, "", 0, tbPassphrase.Text); // Format = kffAuto, KeyType = ktAuto

                crypto.Key = keymanager.Key;
            }
        }


        private void DoSignDetached()
		{
            PublicKeyCrypto crypto = new PublicKeyCrypto();
            try 
			{
                switch (comboEncoding.SelectedIndex)
                {
                    case 1: crypto.OutputEncoding = PublicKeyCryptoOutputEncodings.cetBase64; break;
                    case 2: crypto.OutputEncoding = PublicKeyCryptoOutputEncodings.cetCompact; break;
                    case 3: crypto.OutputEncoding = PublicKeyCryptoOutputEncodings.cetJSON; break;
                    default: crypto.OutputEncoding = PublicKeyCryptoOutputEncodings.cetBinary; break;
                }

                // loading key
                LoadKeyFromFile(crypto);

                // signing input data
                crypto.SignFile(tbInputFile.Text, tbSignatureFile.Text, true);

				MessageBox.Show("The file was signed successfully", "Succes", MessageBoxButtons.OK, MessageBoxIcon.Information);
			} 
			catch(Exception e) 
			{
                MessageBox.Show(e.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
			}
        }


        private void DoVerifyDetached()
        {
            PublicKeyCrypto crypto = new PublicKeyCrypto();
            try
            {
                switch (comboEncoding.SelectedIndex)
                {
                    case 1: crypto.InputEncoding = PublicKeyCryptoInputEncodings.cetBase64; break;
                    case 2: crypto.InputEncoding = PublicKeyCryptoInputEncodings.cetCompact; break;
                    case 3: crypto.InputEncoding = PublicKeyCryptoInputEncodings.cetJSON; break;
                    default: crypto.InputEncoding = PublicKeyCryptoInputEncodings.cetBinary; break;
                }

                // loading key
                LoadKeyFromFile(crypto);

                // verifying input data
                crypto.VerifyDetachedFile(tbInputFile.Text, tbSignatureFile.Text);

                switch (crypto.SignatureValidationResult)
                {
                    case PublicKeyCryptoSignatureValidationResults.svtValid: MessageBox.Show("Verification succeeded", "Succes", MessageBoxButtons.OK, MessageBoxIcon.Information); break;
                    case PublicKeyCryptoSignatureValidationResults.svtCorrupted: MessageBox.Show("Verification corrupted", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); break;
                    case PublicKeyCryptoSignatureValidationResults.svtFailure: MessageBox.Show("Verification failed", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); break;
                    default: MessageBox.Show("Verification unknown", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); break;
                }
            }
            catch (Exception e)
            {
                MessageBox.Show(e.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }

		private void btnBrowseInputFile_Click(object sender, System.EventArgs e)
		{
			if (dlgOpenFile.ShowDialog() == DialogResult.OK)
			{
				tbInputFile.Text = dlgOpenFile.FileName;
			}
		}

		private void btnBrowseOutputFile_Click(object sender, System.EventArgs e)
		{
            if (rbSign.Checked)
            {
                if (dlgSaveFile.ShowDialog() == DialogResult.OK)
                {
                    tbSignatureFile.Text = dlgSaveFile.FileName;
                }
            }
            else
            {
                if (dlgOpenFile.ShowDialog() == DialogResult.OK)
                {
                    tbSignatureFile.Text = dlgOpenFile.FileName;
                }
            }
		}

		private void btnBrowseKeyFile_Click(object sender, System.EventArgs e)
		{
			if (dlgOpenKeyFile.ShowDialog() == DialogResult.OK)
			{
				tbKeyFile.Text = dlgOpenKeyFile.FileName;
			}
		}

		private void frmMainForm_Load(object sender, System.EventArgs e)
		{
			comboEncoding.SelectedIndex = 0;
			comboKeyContainerType.SelectedIndex = 0;
            comboKeyAlg.SelectedIndex = 0;
        }

        private void rbSign_CheckedChanged(object sender, EventArgs e)
        {
            if (rbSign.Checked)
            {
                lblSignatureFilename.Text = "Output filename:";
                btnGo.Text = "Sign";
            }
            else
            {
                lblSignatureFilename.Text = "Signature filename:";
                btnGo.Text = "Verify";
            }
        }

        private void comboKeyContainerType_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (comboKeyContainerType.SelectedIndex == 0)
            {
                lblKeyAlg.Enabled = true;
                comboKeyAlg.Enabled = true;
                comboKeyAlg.SelectedIndex = 0;
            }
            else
            {
                lblKeyAlg.Enabled = false;
                comboKeyAlg.Enabled = false;
                comboKeyAlg.SelectedIndex = 0;
            }
        }

        private void comboKeyAlg_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (comboKeyAlg.Text == "EC")
            {
                lblCurve.Enabled = comboKeyAlg.Enabled;
                comboCurve.Enabled = comboKeyAlg.Enabled;
                comboCurve.SelectedIndex = 0;
            }
            else
            {
                lblCurve.Enabled = false;
                comboCurve.Enabled = false;
                comboCurve.SelectedIndex = 0;
            }
        }

        private void btnGo_Click(object sender, EventArgs e)
        {
            if (!System.IO.File.Exists(tbInputFile.Text))
                MessageBox.Show("Source file not found");
            else if (tbSignatureFile.Text == "")
                MessageBox.Show("Please, select output file");
            else if (!System.IO.File.Exists(tbKeyFile.Text))
                MessageBox.Show("Key or certificate file not found");
            else
            {
                if (rbSign.Checked)
                {
                    DoSignDetached();
                }
                else
                {
                    if (!System.IO.File.Exists(tbSignatureFile.Text))
                    {
                        MessageBox.Show("Signature file not found");
                    }
                    else
                    {
                        DoVerifyDetached();
                    }
                }
            }
        }
    }
}