方法一: 02 //须添加对System.Web的引用 03 using System.Web.Security; 04 05 ... 06 07 /// <summary> 08 /// SHA1加密字符串 09 /// </summary> 10 /// <param name="source">源字符串</param> 11 /// <returns>加密后的字符串</returns> 12 public string SHA1(string source) 13 { 14 return FormsAuthentication.HashPasswordForStoringInConfigFile(source, "SHA1"); 15 } 16 17 18 /// <summary> 19 /// MD5加密字符串 20 /// </summary> 21 /// <param name="source">源字符串</param> 22 /// <returns>加密后的字符串</returns> 23 public string MD5(string source) 24 { 25 return FormsAuthentication.HashPasswordForStoringInConfigFile(source, "MD5");; 26 } view sourceprint?01 方法二(可逆加密解密): 02 using System.Security.Cryptography; 03 04 ... 05 06 public string Encode(string data) 07 { 08 byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64); 09 byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64); 10 11 DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider(); 12 int i = cryptoProvider.KeySize; 13 MemoryStream ms = new MemoryStream(); 14 CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateEncryptor(byKey, byIV), CryptoStreamMode.Write); 15 16 StreamWriter sw = new StreamWriter(cst); 17 sw.Write(data); 18 sw.Flush(); 19 cst.FlushFinalBlock(); 20 sw.Flush(); 21 return Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length); 22 23 } 24 25 public string Decode(string data) 26 { 27 byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64); 28 byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64); 29 30 byte[] byEnc; 31 try 32 { 33 byEnc = Convert.FromBase64String(data); 34 } 35 catch 36 { 37 return null; 38 } 39 40 DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider(); 41 MemoryStream ms = new MemoryStream(byEnc); 42 CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateDecryptor(byKey, byIV), CryptoStreamMode.Read); 43 StreamReader sr = new StreamReader(cst); 44 return sr.ReadToEnd(); 45 } view sourceprint?01 方法三(MD5不可逆): 02 using System.Security.Cryptography; 03 04 ... 05 06 //MD5不可逆加密 07 08 //32位加密 09 10 public string GetMD5_32(string s, string _input_charset) 11 { 12 MD5 md5 = new MD5CryptoServiceProvider(); 13 byte[] t = md5.ComputeHash(Encoding.GetEncoding(_input_charset).GetBytes(s)); 14 StringBuilder sb = new StringBuilder(32); 15 for (int i = 0; i < t.Length; i++) 16 { 17 sb.Append(t[i].ToString("x").PadLeft(2, '0')); 18 } 19 return sb.ToString(); 20 } 21 22 //16位加密 23 public static string GetMd5_16(string ConvertString) 24 { 25 MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider(); 26 string t2 = BitConverter.ToString(md5.ComputeHash(UTF8Encoding.Default.GetBytes(ConvertString)), 4, 8); 27 t2 = t2.Replace("-", ""); 28 return t2; 29 } view sourceprint?01 方法四(对称加密): 02 using System.IO; 03 using System.Security.Cryptography; 04 05 ... 06 07 private SymmetricAlgorithm mobjCryptoService; 08 private string Key; 09 /// <summary> 10 /// 对称加密类的构造函数 11 /// </summary> 12 public SymmetricMethod() 13 { 14 mobjCryptoService = new RijndaelManaged(); 15 Key = "Guz(%&hj7x89H$yuBI0456FtmaT5&fvHUFCy76*h%(HilJ$lhj!y6&(*jkP87jH7"; 16 } 17 /// <summary> 18 /// 获得密钥 19 /// </summary> 20 /// <returns>密钥</returns> 21 private byte[] GetLegalKey() 22 { 23 string sTemp = Key; 24 mobjCryptoService.GenerateKey(); 25 byte[] bytTemp = mobjCryptoService.Key; 26 int KeyLength = bytTemp.Length; 27 if (sTemp.Length > KeyLength) 28 sTemp = sTemp.Substring(0, KeyLength); 29 else if (sTemp.Length < KeyLength) 30 sTemp = sTemp.PadRight(KeyLength, ' '); 31 return ASCIIEncoding.ASCII.GetBytes(sTemp); 32 } 33 /// <summary> 34 /// 获得初始向量IV 35 /// </summary> 36 /// <returns>初试向量IV</returns> 37 private byte[] GetLegalIV() 38 { 39 string sTemp = "E4ghj*Ghg7!rNIfb&95GUY86GfghUb#er57HBh(u%g6HJ($jhWk7&!hg4ui%$hjk"; 40 mobjCryptoService.GenerateIV(); 41 byte[] bytTemp = mobjCryptoService.IV; 42 int IVLength = bytTemp.Length; 43 if (sTemp.Length > IVLength) 44 sTemp = sTemp.Substring(0, IVLength); 45 else if (sTemp.Length < IVLength) 46 sTemp = sTemp.PadRight(IVLength, ' '); 47 return ASCIIEncoding.ASCII.GetBytes(sTemp); 48 } 49 /// <summary> 50 /// 加密方法 51 /// </summary> 52 /// <param name="Source">待加密的串</param> 53 /// <returns>经过加密的串</returns> 54 public string Encrypto(string Source) 55 { 56 byte[] bytIn = UTF8Encoding.UTF8.GetBytes(Source); 57 MemoryStream ms = new MemoryStream(); 58 mobjCryptoService.Key = GetLegalKey(); 59 mobjCryptoService.IV = GetLegalIV(); 60 ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor(); 61 CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write); 62 cs.Write(bytIn, 0, bytIn.Length); 63 cs.FlushFinalBlock(); 64 ms.Close(); 65 byte[] bytOut = ms.ToArray(); 66 return Convert.ToBase64String(bytOut); 67 } 68 /// <summary> 69 /// 解密方法 70 /// </summary> 71 /// <param name="Source">待解密的串</param> 72 /// <returns>经过解密的串</returns> 73 public string Decrypto(string Source) 74 { 75 byte[] bytIn = Convert.FromBase64String(Source); 76 MemoryStream ms = new MemoryStream(bytIn, 0, bytIn.Length); 77 mobjCryptoService.Key = GetLegalKey(); 78 mobjCryptoService.IV = GetLegalIV(); 79 ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor(); 80 CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read); 81 StreamReader sr = new StreamReader(cs); 82 return sr.ReadToEnd(); 83 } view sourceprint?01 方法五: 02 using System.IO; 03 using System.Security.Cryptography; 04 using System.Text; 05 06 ... 07 08 //默认密钥向量 09 private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF }; 10 /// <summary> 11 /// DES加密字符串 12 /// </summary> 13 /// <param name="encryptString">待加密的字符串</param> 14 /// <param name="encryptKey">加密密钥,要求为8位</param> 15 /// <returns>加密成功返回加密后的字符串,失败返回源串</returns> 16 public static string EncryptDES(string encryptString, string encryptKey) 17 { 18 try 19 { 20 byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8)); 21 byte[] rgbIV = Keys; 22 byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString); 23 DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider(); 24 MemoryStream mStream = new MemoryStream(); 25 CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write); 26 cStream.Write(inputByteArray, 0, inputByteArray.Length); 27 cStream.FlushFinalBlock(); 28 return Convert.ToBase64String(mStream.ToArray()); 29 } 30 catch 31 { 32 return encryptString; 33 } 34 } 35 36 /// <summary> 37 /// DES解密字符串 38 /// </summary> 39 /// <param name="decryptString">待解密的字符串</param> 40 /// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同</param> 41 /// <returns>解密成功返回解密后的字符串,失败返源串</returns> 42 public static string DecryptDES(string decryptString, string decryptKey) 43 { 44 try 45 { 46 byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey); 47 byte[] rgbIV = Keys; 48 byte[] inputByteArray = Convert.FromBase64String(decryptString); 49 DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider(); 50 MemoryStream mStream = new MemoryStream(); 51 CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write); 52 cStream.Write(inputByteArray, 0, inputByteArray.Length); 53 cStream.FlushFinalBlock(); 54 return Encoding.UTF8.GetString(mStream.ToArray()); 55 } 56 catch 57 { 58 return decryptString; 59 } 60 } view sourceprint?01 方法六(文件加密): 02 using System.IO; 03 using System.Security.Cryptography; 04 using System.Text; 05 06 ... 07 08 //加密文件 09 private static void EncryptData(String inName, String outName, byte[] desKey, byte[] desIV) 10 { 11 //Create the file streams to handle the input and output files. 12 FileStream fin = new FileStream(inName, FileMode.Open, FileAccess.Read); 13 FileStream fout = new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write); 14 fout.SetLength(0); 15 16 //Create variables to help with read and write. 17 byte[] bin = new byte[100]; //This is intermediate storage for the encryption. 18 long rdlen = 0; //This is the total number of bytes written. 19 long totlen = fin.Length; //This is the total length of the input file. 20 int len; //This is the number of bytes to be written at a time. 21 22 DES des = new DESCryptoServiceProvider(); 23 CryptoStream encStream = new CryptoStream(fout, des.CreateEncryptor(desKey, desIV), CryptoStreamMode.Write); 24 25 //Read from the input file, then encrypt and write to the output file. 26 while (rdlen < totlen) 27 { 28 len = fin.Read(bin, 0, 100); 29 encStream.Write(bin, 0, len); 30 rdlen = rdlen + len; 31 } 32 33 encStream.Close(); 34 fout.Close(); 35 fin.Close(); 36 } 37 38 //解密文件 39 private static void DecryptData(String inName, String outName, byte[] desKey, byte[] desIV) 40 { 41 //Create the file streams to handle the input and output files. 42 FileStream fin = new FileStream(inName, FileMode.Open, FileAccess.Read); 43 FileStream fout = new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write); 44 fout.SetLength(0); 45 46 //Create variables to help with read and write. 47 byte[] bin = new byte[100]; //This is intermediate storage for the encryption. 48 long rdlen = 0; //This is the total number of bytes written. 49 long totlen = fin.Length; //This is the total length of the input file. 50 int len; //This is the number of bytes to be written at a time. 51 52 DES des = new DESCryptoServiceProvider(); 53 CryptoStream encStream = new CryptoStream(fout, des.CreateDecryptor(desKey, desIV), CryptoStreamMode.Write); 54 55 //Read from the input file, then encrypt and write to the output file. 56 while (rdlen < totlen) 57 { 58 len = fin.Read(bin, 0, 100); 59 encStream.Write(bin, 0, len); 60 rdlen = rdlen + len; 61 } 62 63 encStream.Close(); 64 fout.Close(); 65 fin.Close(); 66 67 } view sourceprint?01 using System; 02 using System.Security.Cryptography;//这个是处理文字编码的前提 03 using System.Text; 04 using System.IO; 05 /// <summary> 06 /// DES加密方法 07 /// </summary> 08 /// <param name="strPlain">明文</param> 09 /// <param name="strDESKey">密钥</param> 10 /// <param name="strDESIV">向量</param> 11 /// <returns>密文</returns> 12 public string DESEncrypt(string strPlain,string strDESKey,string strDESIV) 13 { 14 //把密钥转换成字节数组 15 byte[] bytesDESKey=ASCIIEncoding.ASCII.GetBytes(strDESKey); 16 //把向量转换成字节数组 17 byte[] bytesDESIV=ASCIIEncoding.ASCII.GetBytes(strDESIV); 18 //声明1个新的DES对象 19 DESCryptoServiceProvider desEncrypt=new DESCryptoServiceProvider(); 20 //开辟一块内存流 21 MemoryStream msEncrypt=new MemoryStream(); 22 //把内存流对象包装成加密流对象 23 CryptoStream csEncrypt=new CryptoStream(msEncrypt,desEncrypt.CreateEncryptor(bytesDESKey,bytesDESIV),CryptoStreamMode.Write); 24 //把加密流对象包装成写入流对象 25 StreamWriter swEncrypt=new StreamWriter(csEncrypt); 26 //写入流对象写入明文 27 swEncrypt.WriteLine(strPlain); 28 //写入流关闭 29 swEncrypt.Close(); 30 //加密流关闭 31 csEncrypt.Close(); 32 //把内存流转换成字节数组,内存流现在已经是密文了 33 byte[] bytesCipher=msEncrypt.ToArray(); 34 //内存流关闭 35 msEncrypt.Close(); 36 //把密文字节数组转换为字符串,并返回 37 return UnicodeEncoding.Unicode.GetString(bytesCipher); 38 } 39 40 41 42 43 /// <summary> 44 /// DES解密方法 45 /// </summary> 46 /// <param name="strCipher">密文</param> 47 /// <param name="strDESKey">密钥</param> 48 /// <param name="strDESIV">向量</param> 49 /// <returns>明文</returns> 50 public string DESDecrypt(string strCipher,string strDESKey,string strDESIV) 51 { 52 //把密钥转换成字节数组 53 byte[] bytesDESKey=ASCIIEncoding.ASCII.GetBytes(strDESKey); 54 //把向量转换成字节数组 55 byte[] bytesDESIV=ASCIIEncoding.ASCII.GetBytes(strDESIV); 56 //把密文转换成字节数组 57 byte[] bytesCipher=UnicodeEncoding.Unicode.GetBytes(strCipher); 58 //声明1个新的DES对象 59 DESCryptoServiceProvider desDecrypt=new DESCryptoServiceProvider(); 60 //开辟一块内存流,并存放密文字节数组 61 MemoryStream msDecrypt=new MemoryStream(bytesCipher); 62 //把内存流对象包装成解密流对象 63 CryptoStream csDecrypt=new CryptoStream(msDecrypt,desDecrypt.CreateDecryptor(bytesDESKey,bytesDESIV),CryptoStreamMode.Read); 64 //把解密流对象包装成读出流对象 65 StreamReader srDecrypt=new StreamReader(csDecrypt); 66 //明文=读出流的读出内容 67 string strPlainText=srDecrypt.ReadLine(); 68 //读出流关闭 69 srDecrypt.Close(); 70 //解密流关闭 71 csDecrypt.Close(); 72 //内存流关闭 73 msDecrypt.Close(); 74 //返回明文 75 return strPlainText; 76 } 本文来自:http://www.cnblogs.com/zengxiangzhan/archive/2010/01/30/1659687.html