一小女生求我用C#写个加密解密的小程序，可我不会C#,200分求大侠给我一个这样的程序。

using System;
using System.IO;
using System.Text;
using System.Collections;
using System.Security.Cryptography;namespace Encryption
{
/// <summary>
/// Summary description for Crptography.
/// Uses TripleDES Symmetric alogorithm to encrypt and decyrpt streams.
/// This algorithm uses a 24 byte key and a 8 byte initialization vector.
/// </summary>
public class Cryptography
{
//DES instance with random key
private TripleDESCryptoServiceProvider des ;
private ICryptoTransform encrypt; //Encryptor
private ICryptoTransform decrypt; // Decryptor public Cryptography()
{
des = new  TripleDESCryptoServiceProvider();
string strKey = "this is a key for doing encryption"; // This is made a constant here. it can be mentioned in a config file also.
byte[] key = Get24ByteKey(strKey);
byte[] ivector = Get8ByteInitializationVector(strKey);

//create DES Encryptor from this instance
encrypt = des.CreateEncryptor(key,ivector); //create DES Decryptor from our des instance
decrypt = des.CreateDecryptor(key,ivector); }
public Stream Encrypt(Stream StreamtoEncrypt)
{
int len = (int) StreamtoEncrypt.Length;
byte[] bytearrayinput = new byte[len]; // Intermediate storage for Encryption
int i = StreamtoEncrypt.Read(bytearrayinput,0,bytearrayinput.Length); //The encryptor takes bytearray as the input.So read the data from stream into bytearray

byte[] bytearrayoutput = encrypt.TransformFinalBlock(bytearrayinput,0,bytearrayinput.Length);

MemoryStream EncryptedStream = new MemoryStream();
EncryptedStream.Write(bytearrayoutput,0,bytearrayoutput.Length); // Write the output into  a Stream to return a Stream
EncryptedStream.Position = 0; // Set position to zero.

return EncryptedStream; // Return the encryptedstream
} public Stream Decrypt(Stream StreamtoDecrypt)
{
string StrtoDecrypt= new StreamReader(StreamtoDecrypt,new UnicodeEncoding()).ReadToEnd(); // The input stream here doesnot have length defined. So convert it to a StreamReader.
byte[] bytearrayinput = new byte[4096];
bytearrayinput =new UnicodeEncoding().GetBytes(StrtoDecrypt);  //The decryptor takes bytearray as the input.

byte[] bytearrayoutput = decrypt.TransformFinalBlock(bytearrayinput,0,bytearrayinput.Length);

MemoryStream DecryptedStream = new MemoryStream();
DecryptedStream.Write(bytearrayoutput,0,bytearrayoutput.Length); // Write the output into  a Stream to return a Stream
DecryptedStream.Position= 0; // Set position to zero.

return DecryptedStream; // Return the decryptedstream
} private static byte[] Get24ByteKey(string phrase)
{
// Takes any string and returns a 24 byte array
SHA256 sh = new SHA256Managed();
byte[] hash = sh.ComputeHash(new UnicodeEncoding().GetBytes(phrase));
byte[] retVal = new byte[24];
for (int j=0; j < retVal.Length; j++)
{
retVal.SetValue(hash.GetValue(j),j); }
return retVal;
} private static byte[] Get8ByteInitializationVector(string phrase)
{
// Takes any string and returns a 8 byte array
SHA256 sh = new SHA256Managed();
byte[] hash = sh.ComputeHash(new UnicodeEncoding().GetBytes(phrase));
byte[] retVal = new byte[8];
for (int j=0; j < retVal.Length; j++)
{
retVal.SetValue(hash.GetValue(j),j);
}
return retVal;
}
}
}

正如楼上所言，就用System.Security.Cryptography;命名空间的类，看看MSDN就知道了不是很难的，呵呵

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
//使用System.IO命名空间中的FileStream类进行文件io操作。
using System.IO ;
//使用System.Security.Cryptography命名空间中的DESCryptoServiceProvider类进行加密解密。
using System.Security.Cryptography;
namespace test
{
/// <summary>
/// Form1 的摘要说明。
/// </summary>
public class Form1 : System.Windows.Forms.Form
{
    private System.Windows.Forms.Button button1;
/// <summary>
/// 必需的设计器变量。
/// </summary>
private System.ComponentModel.Container components = null; public Form1()
{
//
// Windows 窗体设计器支持所必需的
//
InitializeComponent(); //
// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
//
} /// <summary>
/// 清理所有正在使用的资源。
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
} #region Windows Form Designer generated code
/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
      this.button1 = new System.Windows.Forms.Button();
      this.SuspendLayout();
      //
      // button1
      //
      this.button1.Location = new System.Drawing.Point(64, 56);
      this.button1.Name = "button1";
      this.button1.TabIndex = 0;
      this.button1.Text = "button1";
      this.button1.Click += new System.EventHandler(this.button1_Click);
      //
      // Form1
      //
      this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
      this.ClientSize = new System.Drawing.Size(224, 166);
      this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                                                  this.button1});
      this.Name = "Form1";
      this.Text = "Form1";
      this.ResumeLayout(false);    }
#endregion /// <summary>
/// 应用程序的主入口点。
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Form1());
}    //加密函数myEndata，inName为输入文件，outName为输出文件，desKey为des加密算法的密钥，desIV为des算法的加密向量。密钥和向量要求是8位byte数组。因为私钥算法是对称算法，所以把CryptoStream类实例化语句中的des.CreateEncryptor改为des.CreateDecryptor即成为解密函数。
    private static void myEndata(String inName, String outName, byte[] desKey, byte[] desIV)
    {
      //Create the file streams to handle the input and output files.
      FileStream fin = new FileStream(inName, FileMode.Open, FileAccess.Read);
      FileStream fout = new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write);
      fout.SetLength(0);

      //Create variables to help with read and write.
      byte[] bin = new byte[100]; //This is intermediate storage for the encryption.
      long rdlen = 0;              //This is the total number of bytes written.
      long totlen = fin.Length;    //This is the total length of the input file.
      int len;                     //This is the number of bytes to be written at a time.

      DES des = new DESCryptoServiceProvider();
      CryptoStream encStream = new CryptoStream(fout, des.CreateEncryptor(desKey, desIV), CryptoStreamMode.Write);

      //Read from the input file, then encrypt and write to the output file.
      while(rdlen < totlen)
      {
        len = fin.Read(bin, 0, 100);
        encStream.Write(bin, 0, len);
        rdlen = rdlen + len;
        Console.WriteLine("{0} bytes processed", rdlen);
      }

      encStream.Close();
      fout.Close();
      fin.Close();
    }    //解密函数myDedata，inName为输入文件，outName为输出文件，desKey为des加密算法的密钥，desIV为des算法的加密向量。密钥和向量要求是8位byte数组，必须和加密时一样。其实这个函数和加密函数只有CreateDecryptor和CreateEncryptor这一处不同。
    private static void myDedata(String inName, String outName, byte[] desKey, byte[] desIV)
    {
      //Create the file streams to handle the input and output files.
      FileStream fin = new FileStream(inName, FileMode.Open, FileAccess.Read);
      FileStream fout = new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write);
      fout.SetLength(0);

      //Create variables to help with read and write.
      byte[] bin = new byte[100]; //This is intermediate storage for the encryption.
      long rdlen = 0;              //This is the total number of bytes written.
      long totlen = fin.Length;    //This is the total length of the input file.
      int len;                     //This is the number of bytes to be written at a time.

      DES des = new DESCryptoServiceProvider();
      CryptoStream encStream = new CryptoStream(fout, des.CreateDecryptor(desKey, desIV), CryptoStreamMode.Write);

      //Read from the input file, then encrypt and write to the output file.
      while(rdlen < totlen)
      {
        len = fin.Read(bin, 0, 100);
        encStream.Write(bin, 0, len);
        rdlen = rdlen + len;
        Console.WriteLine("{0} bytes processed", rdlen);
      }

      encStream.Close();
      fout.Close();
      fin.Close();
    }
    //在button1的Click事件中调用加密函数，把in.txt加密，输出到out.txt，在把out.txt解密后输出到out2.txt.
    private void button1_Click(object sender, System.EventArgs e)
    {
      byte[] myDesKey={11,22,33,44,55,66,77,88};
      byte[] myDesIV={88,77,66,55,44,33,22,11};
      myEndata("c:\\in.txt","c:\\out.txt",myDesKey,myDesIV);
      myDedata("c:\\out.txt","c:\\out2.txt",myDesKey,myDesIV);
    }
}
}

//名称空间
using  System;
using  System.Security.Cryptography;
using  System.IO;
using  System.Text;

//方法
//加密方法
public    string  Encrypt(string  pToEncrypt,  string  sKey)
{
           DESCryptoServiceProvider  des  =  new  DESCryptoServiceProvider();
           //把字符串放到byte数组中
                 //原来使用的UTF8编码，我改成Unicode编码了，不行
           byte[]  inputByteArray  =  Encoding.Default.GetBytes(pToEncrypt);
           //byte[]  inputByteArray=Encoding.Unicode.GetBytes(pToEncrypt);

           //建立加密对象的密钥和偏移量
           //原文使用ASCIIEncoding.ASCII方法的GetBytes方法
           //使得输入密码必须输入英文文本
           des.Key  =  ASCIIEncoding.ASCII.GetBytes(sKey);
           des.IV  =  ASCIIEncoding.ASCII.GetBytes(sKey);
           MemoryStream  ms  =  new  MemoryStream();
           CryptoStream  cs  =  new  CryptoStream(ms,  des.CreateEncryptor(),CryptoStreamMode.Write);
           //Write  the  byte  array  into  the  crypto  stream
           //(It  will  end  up  in  the  memory  stream)
           cs.Write(inputByteArray,  0,  inputByteArray.Length);
           cs.FlushFinalBlock();
           //Get  the  data  back  from  the  memory  stream,  and  into  a  string
           StringBuilder  ret  =  new  StringBuilder();
           foreach(byte  b  in  ms.ToArray())
                       {
                       //Format  as  hex
                       ret.AppendFormat("{0:X2}",  b);
                       }
           ret.ToString();
           return  ret.ToString();
}

//解密方法
public    string  Decrypt(string  pToDecrypt,  string  sKey)
{
           DESCryptoServiceProvider  des  =  new  DESCryptoServiceProvider();

           //Put  the  input  string  into  the  byte  array
           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;
           }

           //建立加密对象的密钥和偏移量，此值重要，不能修改
           des.Key  =  ASCIIEncoding.ASCII.GetBytes(sKey);
           des.IV  =  ASCIIEncoding.ASCII.GetBytes(sKey);
           MemoryStream  ms  =  new  MemoryStream();
           CryptoStream  cs  =  new  CryptoStream(ms,  des.CreateDecryptor(),CryptoStreamMode.Write);
           //Flush  the  data  through  the  crypto  stream  into  the  memory  stream
           cs.Write(inputByteArray,  0,  inputByteArray.Length);
           cs.FlushFinalBlock();

           //Get  the  decrypted  data  back  from  the  memory  stream
           //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.Default.GetString(ms.ToArray());
}

//-------代码完毕--------------------

注意：sKey输入密码的时候，必须使用英文字符，区分大小写，且字符数量是8个，不能多也不能少，否则出错。

谢谢上面的各位大侠。谢谢！我还有个过分的问题，就是怎么把上面的代码放到项目里呀？我新创建了一个项目，把代码copy进去，有错。由于我一点也不会C# ，所以还请大侠指点。或者那位大哥大姐直接给我一个完整的项目文件吧。
我又开了一个新贴，上面的各位只要去了就给分。
http://expert.csdn.net/Expert/topic/1870/1870019.xml?temp=6.286258E-02

调试易

一小女生求我用C#写个加密解密的小程序，可我不会C#,200分求大侠给我一个这样的程序。

解决方案 »