?using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Security.Cryptography;
using System.Text;
using System.IO;

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

        RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
        private void btEncoding_Click(object sender, EventArgs e)
        {
            if (mbox.Text == "")
            {
                MessageBox.Show("加密文字信息不能為空！");
                return;
            }
            if (publicKey.Text =="")
            {
                MessageBox.Show("請(qǐng)生成公鑰！");
                return;
            }
            try
            {
                string pubKey = publicKey.Text;
                byte[] mw = ASCIIEncoding.ASCII.GetBytes(mbox.Text);
                RSACryptoServiceProvider crypt = new RSACryptoServiceProvider();
                crypt.FromXmlString(pubKey);
                
                mw = crypt.Encrypt(mw, false);
                string encryttext = Convert.ToBase64String(mw);//加密后的結(jié)果怎樣處理解決顯示亂碼問題
                cbox.Text = encryttext;
            }
            catch
            {
                MessageBox.Show("請(qǐng)檢查是否打開公匙或者公匙是否損壞！");

            } 

        }

        private void btDecoding_Click(object sender, EventArgs e)
        {
            if (cbox.Text =="")
            {
                MessageBox.Show("請(qǐng)生成密鑰！");
                return;
            }
            try
            {
                RSACryptoServiceProvider crypt = new RSACryptoServiceProvider();
                byte[] bytes = Convert.FromBase64String(cbox.Text);//從密文框中取出的字符串正確處理才能解密
                string prtKey = privateKey.Text;
                crypt.FromXmlString(prtKey);
                byte[] decryptbyte = crypt.Decrypt(bytes, false);
                string decrypttext = Encoding.Default.GetString(decryptbyte);
                    
                mbox.Text = decrypttext ;
            }
            catch(CryptographicException ex)
            {
                //MessageBox.Show("請(qǐng)檢查是否打開私匙或者私匙是否損壞！");
                MessageBox.Show(ex.ToString());
            }  

        }

        private void button1_Click(object sender, EventArgs e)
        {
            RSACryptoServiceProvider rs = new RSACryptoServiceProvider();
            publicKey.Text = rs.ToXmlString(false);
            privateKey.Text = rs.ToXmlString(true);
        }
    }
}