c#设计程序，保存时加密，读取时解密

Question

设计一个程序，把连接字符串保存在硬盘里，每次启动程序的时候可以读取该字符串，用来连接数据库。由于连接字符串里有用户名和密码等信息，必须加密保存，读取时解密。麻烦带代码，详细一点，感激

Answer 1

可以用DES加密解密，新建一个Crypt.cs文件，贴入下面的代码

using System;
using System.Security.Cryptography;
using System.Text;
using System.IO;
/// <summary>
/// 加密解密类
/// </summary>
public class Crypt
{
    private static string deskey = "12344321";//密钥，长度为8个字符
    /// <summary>
    /// DEC 加密过程
    /// </summary>
    /// <param name="pToDecrypt">被解密的字符串</param>
    /// <returns>返回被解密的字符串</returns>
    public static string Encrypt(string pToEncrypt)
    {
        //访问数据加密标准(DES)算法的加密服务提供程序 (CSP) 版本的包装对象
        DESCryptoServiceProvider des = new DESCryptoServiceProvider();
        des.Key = ASCIIEncoding.ASCII.GetBytes(deskey);　//建立加密对象的密钥和偏移量
        des.IV = ASCIIEncoding.ASCII.GetBytes(deskey);　 //原文使用ASCIIEncoding.ASCII方法的GetBytes方法

        byte[] inputByteArray = Encoding.UTF8.GetBytes(pToEncrypt);//把字符串放到byte数组中

        MemoryStream ms = new MemoryStream();//创建其支持存储区为内存的流　
        //定义将数据流链接到加密转换的流
        CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
        cs.Write(inputByteArray, 0, inputByteArray.Length);
        cs.FlushFinalBlock();
        //上面已经完成了把加密后的结果放到内存中去

        StringBuilder ret = new StringBuilder();
        foreach (byte b in ms.ToArray())
        {
            ret.AppendFormat("{0:X2}", b);
        }
        ret.ToString();
        return ret.ToString();
    }
    /// <summary>
    /// DEC 解密过程
    /// </summary>
    /// <param name="pToDecrypt">被解密的字符串</param>
    /// <returns>返回被解密的字符串</returns>
    public static string Decrypt(string pToDecrypt)
    {
        DESCryptoServiceProvider des = new DESCryptoServiceProvider();

        byte[] inputByteArray = new byte[pToDecrypt.Length / 2];
        for (int x = 0; x < pToDecrypt.Length / 2; x++)
        {
            int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));
            inputByteArray[x] = (byte)i;
        }

        des.Key = ASCIIEncoding.ASCII.GetBytes(deskey);　//建立加密对象的密钥和偏移量，此值重要，不能修改
        des.IV = ASCIIEncoding.ASCII.GetBytes(deskey);
        MemoryStream ms = new MemoryStream();
        CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);

        cs.Write(inputByteArray, 0, inputByteArray.Length);
        cs.FlushFinalBlock();

        //建立StringBuild对象，createDecrypt使用的是流对象，必须把解密后的文本变成流对象
        StringBuilder ret = new StringBuilder();

        return System.Text.Encoding.UTF8.GetString(ms.ToArray());
    }
}

使用示例

        private void button1_Click(object sender, EventArgs e)
        {
            if (textBox1.Text == "") { MessageBox.Show("待加密字符串不能为空！");textBox1.Focus();return; }
            textBox2.Text = Crypt.Encrypt(textBox1.Text);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (textBox2.Text == "") { MessageBox.Show("待解密字符串不能为空！"); textBox1.Focus(); return; }
            textBox1.Text = Crypt.Decrypt(textBox2.Text);
        }

有帮助麻烦点下【采纳该答案】，谢谢~~有其他问题可以继续交流~