【强烈推荐】开源C#工具类MSCL系列（八）Encrypt加密解密帮助类

using System;using System.IO;using System.Security;using System.Security.Cryptography;using System.Text;using System.Web;namespace MSCL{    /// <summary>    /// 加密解密辅助类    /// </summary>    public class EncryptHelper    {        /// <summary>        /// MD5加密不区分大小写的        /// </summary>        /// <param name="pwd">源字符串</param>        /// <param name="type">16位还是32位，16位就是取32位的第8到16位</param>        /// <returns></returns>        public static string Md5Encode(string pwd, int type)        {            byte[] result = Encoding.Default.GetBytes(pwd);            MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();            byte[] output = md5.ComputeHash(result);            if (type == 16)                return BitConverter.ToString(output).Replace("-", "").ToLower().Substring(8, 16);            else                return BitConverter.ToString(output).Replace("-", "").ToLower();        }        /// <summary>        /// 对字符串进行SHA1加密        /// </summary>        /// <param name="Source_String">需要加密的字符串</param>        /// <returns>密文</returns>        public static string SHA1Encrypt(string Source_String)        {            byte[] StrRes = Encoding.Default.GetBytes(Source_String);            HashAlgorithm iSHA = new SHA1CryptoServiceProvider();            StrRes = iSHA.ComputeHash(StrRes);            StringBuilder EnText = new StringBuilder();            foreach (byte iByte in StrRes)            {                EnText.AppendFormat("{0:x2}", iByte);            }            return EnText.ToString();        }        /// <summary>        /// SHA256加密，不可逆转        /// </summary>        /// <param name="str">string str:被加密的字符串</param>        /// <returns>返回加密后的字符串</returns>        public static string SHA256Encrypt(string str)        {            System.Security.Cryptography.SHA256 s256 = new System.Security.Cryptography.SHA256Managed();            byte[] byte1;            byte1 = s256.ComputeHash(Encoding.Default.GetBytes(str));            s256.Clear();            return Convert.ToBase64String(byte1);        }        /// <summary>        /// SHA384加密，不可逆转        /// </summary>        /// <param name="str">string str:被加密的字符串</param>        /// <returns>返回加密后的字符串</returns>        public static string SHA384Encrypt(string str)        {            System.Security.Cryptography.SHA384 s384 = new System.Security.Cryptography.SHA384Managed();            byte[] byte1;            byte1 = s384.ComputeHash(Encoding.Default.GetBytes(str));            s384.Clear();            return Convert.ToBase64String(byte1);        }        /// <summary>        /// SHA512加密，不可逆转        /// </summary>        /// <param name="str">string str:被加密的字符串</param>        /// <returns>返回加密后的字符串</returns>        public static string SHA512Encrypt(string str)        {            System.Security.Cryptography.SHA512 s512 = new System.Security.Cryptography.SHA512Managed();            byte[] byte1;            byte1 = s512.ComputeHash(Encoding.Default.GetBytes(str));            s512.Clear();            return Convert.ToBase64String(byte1);        }        /// <summary>        /// DES加密        /// </summary>        /// <param name="encryptString">待加密的字符串</param>        /// <param name="encryptKey">加密密匙，要求为8位</param>        /// <returns></returns>        public static string EncryptDES(string encryptString, string encryptKey)        {            using (DESCryptoServiceProvider des = new DESCryptoServiceProvider())            {                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);                des.Key = UTF8Encoding.UTF8.GetBytes(encryptKey);// ASCIIEncoding.ASCII.GetBytes(encryptKey);                des.IV = UTF8Encoding.UTF8.GetBytes(encryptKey);                System.IO.MemoryStream ms = new System.IO.MemoryStream();                using (CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write))                {                    cs.Write(inputByteArray, 0, inputByteArray.Length);                    cs.FlushFinalBlock();                    cs.Close();                }                StringBuilder ret = new StringBuilder();                foreach (byte b in ms.ToArray())                {                    ret.AppendFormat("{0:x2}", b);                }                ret.ToString();                return ret.ToString();            }        }        /// <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></returns>        public static string DecryptDES(string decryptString, string decryptKey)        {            DESCryptoServiceProvider des = new DESCryptoServiceProvider();            //put  the  input  string  into  the  byte  array              byte[] inputbytearray = new byte[decryptString.Length / 2];            for (int x = 0; x < decryptString.Length / 2; x++)            {                int i = (Convert.ToInt32(decryptString.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 = UTF8Encoding.UTF8.GetBytes(decryptKey);            des.IV = UTF8Encoding.UTF8.GetBytes(decryptKey);            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 Encoding.UTF8.GetString(ms.ToArray(), 0, ms.ToArray().Length);        }        /// <summary>        /// BASE64加密字符串        /// </summary>        /// <param name="str">源字符串</param>        /// <returns></returns>         public static string Base64Encode(string str)        {            return Convert.ToBase64String(Encoding.UTF8.GetBytes(str));        }        /// <summary>        /// BASE64解密字符串        /// </summary>        /// <param name="base64Str">Base64字串</param>        /// <returns></returns>         public static string Base64Decode(string base64Str)        {            return Encoding.UTF8.GetString(Convert.FromBase64String(base64Str));        }    }}