//须添加对System.Web的引用  using System.Web.Security;  ...  /// <summary>  /// SHA1加密字符串  /// </summary>  /// <param name="source">源字符串</param>  /// <returns>加密后的字符串</returns>  public string SHA1(string source)  {  return FormsAuthentication.HashPasswordForStoringInConfigFile(source, "SHA1");  }  /// <summary>  /// MD5加密字符串  /// </summary>  /// <param name="source">源字符串</param>  /// <returns>加密后的字符串</returns>  public string MD5(string source)  {  return FormsAuthentication.HashPasswordForStoringInConfigFile(source, "MD5");;  }

using System.Security.Cryptography;  ...  public string Encode(string data)  {  byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);  byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);  DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();  int i = cryptoProvider.KeySize;  MemoryStream ms = new MemoryStream();  CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateEncryptor(byKey, byIV), CryptoStreamMode.Write);  StreamWriter sw = new StreamWriter(cst);  sw.Write(data);  sw.Flush();  cst.FlushFinalBlock();  sw.Flush();  return Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length);  }  public string Decode(string data)  {  byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);  byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);  byte[] byEnc;  try  {  byEnc = Convert.FromBase64String(data);  }  catch  {  return null;  }  DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();  MemoryStream ms = new MemoryStream(byEnc);  CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateDecryptor(byKey, byIV), CryptoStreamMode.Read);  StreamReader sr = new StreamReader(cst);  return sr.ReadToEnd();  }

using System.Security.Cryptography;  ...  //MD5不可逆加密  //32位加密  public string GetMD5_32(string s, string _input_charset)  {  MD5 md5 = new MD5CryptoServiceProvider();  byte[] t = md5.ComputeHash(Encoding.GetEncoding(_input_charset).GetBytes(s));  StringBuilder sb = new StringBuilder(32);  for (int i = 0; i < t.Length; i++)  {  sb.Append(t[i].ToString("x").PadLeft(2, '0'));  }  return sb.ToString();  }  //16位加密  public static string GetMd5_16(string ConvertString)  {  MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();  string t2 = BitConverter.ToString(md5.ComputeHash(UTF8Encoding.Default.GetBytes(ConvertString)), 4, 8);  t2 = t2.Replace("-", "");  return t2;  }

using System.IO;  using System.Security.Cryptography;  ...  private SymmetricAlgorithm mobjCryptoService;  private string Key;  /// <summary>  /// 对称加密类的构造函数  /// </summary>  public SymmetricMethod()  {  mobjCryptoService = new RijndaelManaged();  Key = "Guz(%&hj7x89H$yuBI0456FtmaT5&fvHUFCy76*h%(HilJ$lhj!y6&(*jkP87jH7";  }  /// <summary>  /// 获得密钥  /// </summary>  /// <returns>密钥</returns>  private byte[] GetLegalKey()  {  string sTemp = Key;  mobjCryptoService.GenerateKey();  byte[] bytTemp = mobjCryptoService.Key;  int KeyLength = bytTemp.Length;  if (sTemp.Length > KeyLength)  sTemp = sTemp.Substring(0, KeyLength);  else if (sTemp.Length < KeyLength)  sTemp = sTemp.PadRight(KeyLength, ' ');  return ASCIIEncoding.ASCII.GetBytes(sTemp);  }  /// <summary>  /// 获得初始向量IV  /// </summary>  /// <returns>初试向量IV</returns>  private byte[] GetLegalIV()  {  string sTemp = "E4ghj*Ghg7!rNIfb&95GUY86GfghUb#er57HBh(u%g6HJ($jhWk7&!hg4ui%$hjk";  mobjCryptoService.GenerateIV();  byte[] bytTemp = mobjCryptoService.IV;  int IVLength = bytTemp.Length;  if (sTemp.Length > IVLength)  sTemp = sTemp.Substring(0, IVLength);  else if (sTemp.Length < IVLength)  sTemp = sTemp.PadRight(IVLength, ' ');  return ASCIIEncoding.ASCII.GetBytes(sTemp);  }  /// <summary>  /// 加密方法  /// </summary>  /// <param name="Source">待加密的串</param>  /// <returns>经过加密的串</returns>  public string Encrypto(string Source)  {  byte[] bytIn = UTF8Encoding.UTF8.GetBytes(Source);  MemoryStream ms = new MemoryStream();  mobjCryptoService.Key = GetLegalKey();  mobjCryptoService.IV = GetLegalIV();  ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor();  CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);  cs.Write(bytIn, 0, bytIn.Length);  cs.FlushFinalBlock();  ms.Close();  byte[] bytOut = ms.ToArray();  return Convert.ToBase64String(bytOut);  }  /// <summary>  /// 解密方法  /// </summary>  /// <param name="Source">待解密的串</param>  /// <returns>经过解密的串</returns>  public string Decrypto(string Source)  {  byte[] bytIn = Convert.FromBase64String(Source);  MemoryStream ms = new MemoryStream(bytIn, 0, bytIn.Length);  mobjCryptoService.Key = GetLegalKey();  mobjCryptoService.IV = GetLegalIV();  ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor();  CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);  StreamReader sr = new StreamReader(cs);  return sr.ReadToEnd();  }

using System.IO;  using System.Security.Cryptography;  using System.Text;  ...  //默认密钥向量  private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };  /// <summary>  /// DES加密字符串  /// </summary>  /// <param name="encryptString">待加密的字符串</param>  /// <param name="encryptKey">加密密钥,要求为8位</param>  /// <returns>加密成功返回加密后的字符串，失败返回源串</returns>  public static string EncryptDES(string encryptString, string encryptKey)  {  try  {  byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));  byte[] rgbIV = Keys;  byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);  DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();  MemoryStream mStream = new MemoryStream();  CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);  cStream.Write(inputByteArray, 0, inputByteArray.Length);  cStream.FlushFinalBlock();  return Convert.ToBase64String(mStream.ToArray());  }  catch  {  return encryptString;  }  }  /// <summary>  /// DES解密字符串  /// </summary>  /// <param name="decryptString">待解密的字符串</param>  /// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同</param>  /// <returns>解密成功返回解密后的字符串，失败返源串</returns>  public static string DecryptDES(string decryptString, string decryptKey)  {  try  {  byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);  byte[] rgbIV = Keys;  byte[] inputByteArray = Convert.FromBase64String(decryptString);  DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();  MemoryStream mStream = new MemoryStream();  CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);  cStream.Write(inputByteArray, 0, inputByteArray.Length);  cStream.FlushFinalBlock();  return Encoding.UTF8.GetString(mStream.ToArray());  }  catch  {  return decryptString;  }  }

using System.IO;  using System.Security.Cryptography;  using System.Text;  ...  //加密文件  private static void EncryptData(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;  }  encStream.Close();  fout.Close();  fin.Close();  }  //解密文件  private static void DecryptData(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;  }  encStream.Close();  fout.Close();  fin.Close();  }

using System; using System.Security.Cryptography;//这个是处理文字编码的前提 using System.Text; using System.IO; /// <summary> /// DES加密方法 /// </summary> /// <param name="strPlain">明文</param> /// <param name="strDESKey">密钥</param> /// <param name="strDESIV">向量</param> /// <returns>密文</returns> public string DESEncrypt(string strPlain,string strDESKey,string strDESIV) { //把密钥转换成字节数组 byte[] bytesDESKey=ASCIIEncoding.ASCII.GetBytes(strDESKey); //把向量转换成字节数组 byte[] bytesDESIV=ASCIIEncoding.ASCII.GetBytes(strDESIV); //声明1个新的DES对象 DESCryptoServiceProvider desEncrypt=new DESCryptoServiceProvider(); //开辟一块内存流 MemoryStream msEncrypt=new MemoryStream(); //把内存流对象包装成加密流对象 CryptoStream csEncrypt=new CryptoStream(msEncrypt,desEncrypt.CreateEncryptor(bytesDESKey,bytesDESIV),CryptoStreamMode.Write); //把加密流对象包装成写入流对象 StreamWriter swEncrypt=new StreamWriter(csEncrypt); //写入流对象写入明文 swEncrypt.WriteLine(strPlain); //写入流关闭 swEncrypt.Close(); //加密流关闭 csEncrypt.Close(); //把内存流转换成字节数组，内存流现在已经是密文了 byte[] bytesCipher=msEncrypt.ToArray(); //内存流关闭 msEncrypt.Close(); //把密文字节数组转换为字符串，并返回 return UnicodeEncoding.Unicode.GetString(bytesCipher); } /// <summary> /// DES解密方法 /// </summary> /// <param name="strCipher">密文</param> /// <param name="strDESKey">密钥</param> /// <param name="strDESIV">向量</param> /// <returns>明文</returns> public string DESDecrypt(string strCipher,string strDESKey,string strDESIV) { //把密钥转换成字节数组 byte[] bytesDESKey=ASCIIEncoding.ASCII.GetBytes(strDESKey); //把向量转换成字节数组 byte[] bytesDESIV=ASCIIEncoding.ASCII.GetBytes(strDESIV); //把密文转换成字节数组 byte[] bytesCipher=UnicodeEncoding.Unicode.GetBytes(strCipher); //声明1个新的DES对象 DESCryptoServiceProvider desDecrypt=new DESCryptoServiceProvider(); //开辟一块内存流，并存放密文字节数组 MemoryStream msDecrypt=new MemoryStream(bytesCipher); //把内存流对象包装成解密流对象 CryptoStream csDecrypt=new CryptoStream(msDecrypt,desDecrypt.CreateDecryptor(bytesDESKey,bytesDESIV),CryptoStreamMode.Read); //把解密流对象包装成读出流对象 StreamReader srDecrypt=new StreamReader(csDecrypt); //明文=读出流的读出内容 string strPlainText=srDecrypt.ReadLine(); //读出流关闭 srDecrypt.Close(); //解密流关闭 csDecrypt.Close(); //内存流关闭 msDecrypt.Close(); //返回明文 return strPlainText; }