【转载：http://www.cnblogs.com/Continue/archive/2009/11/20/1606862.html】
在日常的项目开发中，很多时候都会用到加密/解密的功能，以下是我整理出来的一些常见加密/解密的算法：包括MD5加密、SHA256加密、移位加密/解密、DES加密/解密、AES加密/解密，给大家分享一下。
using System;
using System.Collections.Generic;
using System.Text;
using System.Security.Cryptography;
using System.IO;
public class Encrypt
{
MD5加密#region MD5加密
/**//// <summary>
/// MD5加密算法
/// </summary>
/// <param name="PassWord">待加密的字符串</param>
/// <returns>加密后的字符串</returns>
public static string MD5Encrypt(string Input)
{
byte[] b = Encoding.Default.GetBytes(Input);
b = new MD5CryptoServiceProvider().ComputeHash(b);
string ret = "";
for (int i = 0; i < b.Length; i++)
ret += b[i].ToString("x").PadLeft(2, '0');
return ret;
}
/**//// <summary>
/// MD5加密
/// </summary>
/// <param name="Half">加密是16位还是32位；如果为true为16位</param>
/// <param name="Input">待加密码字符串</param>
/// <returns>加密后的字符串</returns>
public static string MD5Encrypt(string Input, bool Half)
{
string output = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(Input, "MD5").ToLower();
if (Half)//16位MD5加密（取32位加密的9~25字符）
output = output.Substring(8, 16);
return output;
}
#endregion
SHA256加密#region SHA256加密
/**//// <summary>
/// SHA256加密
/// </summary>
/// /// <param name="str">待加密的字符串</param>
/// <returns>加密后的字符串</returns>
public static string SHAEncrypt(string str)
{
byte[] SHA256Data = Encoding.UTF8.GetBytes(str);
SHA256Managed Sha256 = new SHA256Managed();
byte[] Result = Sha256.ComputeHash(SHA256Data);
return Convert.ToBase64String(Result); //返回长度为44字节的字符串
}
#endregion
移位加密/解密#region 移位加密/解密
/**//// <summary>
/// 字符串移位加密
/// </summary>
/// <param name="str">待加密数据</param>
/// <returns>加密后的数据</returns>
public static string ShiftEncrypt(string Input)
{
try
{
string _temp = "";
int _inttemp;
char[] _chartemp = Input.ToCharArray();
for (int i = 0; i < _chartemp.Length; i++)
{
_inttemp = _chartemp[i] + 1;
_chartemp[i] = (char)_inttemp;
_temp += _chartemp[i];
}
return _temp;
}
catch
{
return Input.ToString();
}
}
/**//// <summary>
/// 字符串移位解密
/// </summary>
/// <param name="str">待解密数据</param>
/// <returns>解密成功后的数据</returns>
public static string ShiftDecrypt(string Input)
{
try
{
string _temp = "";
int _inttemp;
char[] _chartemp = Input.ToCharArray();
for (int i = 0; i < _chartemp.Length; i++)
{
_inttemp = _chartemp[i] - 1;
_chartemp[i] = (char)_inttemp;
_temp += _chartemp[i];
}
return _temp;
}
catch
{
return Input.ToString();
}
}
#endregion
DES加密/解密#region DES加密/解密
/**//// <summary>
/// DES加密
/// </summary>
/// <param name="Text">待加密的字符串</param>
/// <returns>加密后的字符串</returns>
public static string DESEncrypt(string Text)
{
return DESEncrypt(Text, "Continue");
}
/**//// <summary>
/// DES加密
/// </summary>
/// <param name="Text">待加密的字符串</param>
/// <param name="sKey">加密密钥</param>
/// <returns>加密后的字符串</returns>
public static string DESEncrypt(string Text, string sKey)
{
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
byte[] inputByteArray;
inputByteArray = Encoding.Default.GetBytes(Text);
des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
System.IO.MemoryStream ms = new System.IO.MemoryStream();
CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();
StringBuilder ret = new StringBuilder();
foreach (byte b in ms.ToArray())
{
ret.AppendFormat("{0:X2}", b);
}
return ret.ToString();
}
/**//// <summary>
/// DES解密
/// </summary>
/// <param name="Text">待解密的字符串</param>
/// <returns>解密后的字符串</returns>
public static string DESDecrypt(string Text)
{
return DESDecrypt(Text, "Continue");
}
/**//// <summary>
/// DES解密
/// </summary>
/// <param name="Text">待解密的字符串</param>
/// <param name="sKey">解密密钥</param>
/// <returns>解密后的字符串</returns>
public static string DESDecrypt(string Text, string sKey)
{
try
{
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
int len;
len = Text.Length / 2;
byte[] inputByteArray = new byte[len];
int x, i;
for (x = 0; x < len; x++)
{
i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);
inputByteArray[x] = (byte)i;
}
des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
System.IO.MemoryStream ms = new System.IO.MemoryStream();
CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();
return Encoding.Default.GetString(ms.ToArray());
}
catch
{
return "";
}
}
#endregion
AES加密/解密#region AES加密/解密
//默认密钥向量
private static byte[] Keys = { 0x41, 0x72, 0x65, 0x79, 0x6F, 0x75, 0x6D, 0x79, 0x53, 0x6E, 0x6F, 0x77, 0x6D, 0x61, 0x6E, 0x3F };
/**//// <summary>
/// AES加密
/// </summary>
/// <param name="encryptString">待加密的字符串</param>
/// <param name="encryptKey">加密密钥</param>
/// <returns>加密后的字符串</returns>
public static string AESEncrypt(string encryptString, string encryptKey)
{
encryptKey = GetSubString(encryptKey, 0, 32, "");
encryptKey = encryptKey.PadRight(32, ' ');
RijndaelManaged rijndaelProvider = new RijndaelManaged();
rijndaelProvider.Key = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 32));
rijndaelProvider.IV = Keys;
ICryptoTransform rijndaelEncrypt = rijndaelProvider.CreateEncryptor();
byte[] inputData = Encoding.UTF8.GetBytes(encryptString);
byte[] encryptedData = rijndaelEncrypt.TransformFinalBlock(inputData, 0, inputData.Length);
return Convert.ToBase64String(encryptedData);
}
/**//// <summary>
/// AES加密
/// </summary>
/// <param name="encryptString">待加密的字符串</param>
/// <returns>加密后的字符串</returns>
public static string AESEncrypt(string encryptString)
{
return AESEncrypt(encryptString, "Continue");
}
/**//// <summary>
/// AES解密
/// </summary>
/// <param name="decryptString">待解密的字符串</param>
/// <param name="decryptKey">解密密钥</param>
/// <returns>解密后的字符串</returns>
public static string AESDecrypt(string decryptString, string decryptKey)
{
try
{
decryptKey = GetSubString(decryptKey, 0, 32, "");
decryptKey = decryptKey.PadRight(32, ' ');
RijndaelManaged rijndaelProvider = new RijndaelManaged();
rijndaelProvider.Key = Encoding.UTF8.GetBytes(decryptKey);
rijndaelProvider.IV = Keys;
ICryptoTransform rijndaelDecrypt = rijndaelProvider.CreateDecryptor();
byte[] inputData = Convert.FromBase64String(decryptString);
byte[] decryptedData = rijndaelDecrypt.TransformFinalBlock(inputData, 0, inputData.Length);
return Encoding.UTF8.GetString(decryptedData);
}
catch
{
return "";
}
}
/**//// <summary>
/// AES解密
/// </summary>
/// <param name="decryptString">待解密的字符串</param>
/// <returns>解密后的字符串</returns>
public static string AESDecrypt(string decryptString)
{
return AESDecrypt(decryptString, "Continue");
}
/**//// <summary>
/// 取指定长度的字符串
/// </summary>
/// <param name="p_SrcString">要检查的字符串</param>
/// <param name="p_StartIndex">起始位置</param>
/// <param name="p_Length">指定长度</param>
/// <param name="p_TailString">用于替换的字符串</param>
/// <returns>截取后的字符串</returns>
private static string GetSubString(string p_SrcString, int p_StartIndex, int p_Length, string p_TailString)
{
string myResult = p_SrcString;
Byte[] bComments = Encoding.UTF8.GetBytes(p_SrcString);
foreach (char c in Encoding.UTF8.GetChars(bComments))
{ //当是日文或韩文时(注:中文的范围:\u4e00 - \u9fa5, 日文在\u0800 - \u4e00, 韩文为\xAC00-\xD7A3)
if ((c > '\u0800' && c < '\u4e00') || (c > '\xAC00' && c < '\xD7A3'))
{
//if (System.Text.RegularExpressions.Regex.IsMatch(p_SrcString, "[\u0800-\u4e00]+") || System.Text.RegularExpressions.Regex.IsMatch(p_SrcString, "[\xAC00-\xD7A3]+"))
//当截取的起始位置超出字段串长度时
if (p_StartIndex >= p_SrcString.Length)
return "";
else
return p_SrcString.Substring(p_StartIndex,
((p_Length + p_StartIndex) > p_SrcString.Length) ? (p_SrcString.Length - p_StartIndex) : p_Length);
}
}
if (p_Length >= 0)
{
byte[] bsSrcString = Encoding.Default.GetBytes(p_SrcString);
//当字符串长度大于起始位置
if (bsSrcString.Length > p_StartIndex)
{
int p_EndIndex = bsSrcString.Length;
//当要截取的长度在字符串的有效长度范围内
if (bsSrcString.Length > (p_StartIndex + p_Length))
{
p_EndIndex = p_Length + p_StartIndex;
}
else
{ //当不在有效范围内时,只取到字符串的结尾
p_Length = bsSrcString.Length - p_StartIndex;
p_TailString = "";
}
int nRealLength = p_Length;
int[] anResultFlag = new int[p_Length];
byte[] bsResult = null;
int nFlag = 0;
for (int i = p_StartIndex; i < p_EndIndex; i++)
{
if (bsSrcString[i] > 127)
{
nFlag++;
if (nFlag == 3)
nFlag = 1;
}
else
nFlag = 0;
anResultFlag[i] = nFlag;
}
if ((bsSrcString[p_EndIndex - 1] > 127) && (anResultFlag[p_Length - 1] == 1))
nRealLength = p_Length + 1;
bsResult = new byte[nRealLength];
Array.Copy(bsSrcString, p_StartIndex, bsResult, 0, nRealLength);
myResult = Encoding.Default.GetString(bsResult);
myResult = myResult + p_TailString;
}
}
return myResult;
}
#endregion
}
这里是上面的源代码：点击这里下载
注：
“b[i].ToString(“x”).PadLeft(2, ‘0’);”
byte转十六进制直接ToString(“X2”)就可以了。
