C# 基于密钥的64位加密与解密方法(原创)

本程序适用于产品的价格加密生成图片格式的价格，防止价格被抓去

using System;

/// <summary>
///TTBase64Encode 的摘要说明
/// </summary>
public class TTBase64Encode
{
 public TTBase64Encode()
 {
 //
 //TODO: 在此处添加构造函数逻辑
 //
 }

 const string imgurlhost = "http://img.cblogs.com";
 const string ttBASE_64_MAP_INIT = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 //ReadKeyFromFile(g_KeyLocation)
 const string g_Key = "WERTYUIOFVGBNM663285716";

 string ttnewline;

 string[] ttBase64EncMap = new string[63];
 string[] Base64DecMap = new string[127];

 //初始化函数
 public void ttinitCodecs()
 {
 // 初始化变量
 ttnewline = "<P>" + Convert.ToChar(13) + Convert.ToChar(10);
 dynamic ttmax = null;
 dynamic ttidx = null;
 ttmax = ttBASE_64_MAP_INIT.Length;

 for (ttidx = 0; ttidx <= ttmax - 1; ttidx++)
 {
 ttBase64EncMap[ttidx] = ttBASE_64_MAP_INIT.Substring(ttidx + 1, 1);
 }
 for (ttidx = 0; ttidx <= ttmax - 1; ttidx++)
 {

 Base64DecMap[Asc(ttBase64EncMap[ttidx])] = ttidx;
 }
 }

 /// <summary>
 /// 转化为ascii
 /// </summary>
 /// <param name="s"></param>
 /// <returns></returns>
 protected int stringtoascii(string s)
 {
 string ascii = "";
 foreach (char c in s)
 {
 int str = (int)c;
 ascii += str + ",";
 } if (ascii.Length > 0)
 {
 ascii = ascii.Substring(0, ascii.Length - 1);
 }
 return Convert.ToInt32(ascii);
 }
 /// <summary>
 /// 转化为Ascii
 /// </summary>
 /// <param name="character"></param>
 /// <returns></returns>
 public static int Asc(string character)
 {
 if (character.Length == 1)
 {
 System.Text.ASCIIEncoding asciiEncoding = new System.Text.ASCIIEncoding();
 int intAsciiCode = (int)asciiEncoding.GetBytes(character)[0];
 return (intAsciiCode);
 }
 else
 {
 throw new Exception("Character is not valid.");
 }
 }

 ///Base64加密函数
 public object ttbase64Encode(string price)
 {
 string ttret = string.Empty;
 if (price.Length == 0)
 {
 return "";
 }

 string ttplain = EnCrypt(price).ToString();

 
 dynamic ttndx = null;
 dynamic ttby3 = null;
 dynamic ttfirst = null;
 dynamic ttsecond = null;
 dynamic ttthird = null;
 ttby3 = (ttplain.Length / 3) * 3;
 ttndx = 1;
 while (ttndx <= ttby3)
 {

 ttfirst = Asc(ttplain.Substring(ttndx + 0, 1));
 ttsecond = Asc(ttplain.Substring(ttndx + 1, 1));
 ttthird = Asc(ttplain.Substring(ttndx + 2, 1));
 ttret = ttret + ttBase64EncMap[(ttfirst / 4) & 63];
 ttret = ttret + ttBase64EncMap[((ttfirst * 16) & 48) + ((ttsecond / 16) & 15)];
 ttret = ttret + ttBase64EncMap[((ttsecond * 4) & 60) + ((ttthird / 64) & 3)];
 ttret = ttret + ttBase64EncMap[ttthird & 63];
 ttndx = ttndx + 3;
 }

 if (ttby3 < ttplain.Length)
 {

 ttfirst = Asc(ttplain.Substring(ttndx + 0, 1));
 ttret = ttret + ttBase64EncMap[(ttfirst / 4) & 63];
 if ((ttplain.Length % 3) == 2)
 {

 ttsecond = Asc(ttplain.Substring(ttndx + 1, 1));
 ttret = ttret + ttBase64EncMap[((ttfirst * 16) & 48) + ((ttsecond / 16) & 15)];
 ttret = ttret + ttBase64EncMap[((ttsecond * 4) & 60)];
 }
 else
 {
 ttret = ttret + ttBase64EncMap[(ttfirst * 16) & 48];
 }
 }

 return ttret;
 }
 ////Base64解密函数
 public object ttbase64Decode(string ttscrambled)
 {
 string ttret = string.Empty;
 if (ttscrambled.Length == 0)
 {
 return ttret;
 }
 dynamic ttrealLen = null;
 ttrealLen = ttscrambled.Length;
 while (ttscrambled.Substring(ttrealLen, 1) == "=")
 {
 ttrealLen = ttrealLen - 1;
 }
 
 dynamic ttndx = null;
 dynamic ttby4 = null;
 dynamic ttfirst = null;
 dynamic ttsecond = null;
 dynamic ttthird = null;
 dynamic ttfourth = null;
 ttret = "";
 ttby4 = (ttrealLen / 4) * 4;
 ttndx = 1;

 while (ttndx <= ttby4)
 {
 ttfirst = Base64DecMap[Asc(ttscrambled.Substring(ttndx + 0, 1))];
 ttsecond = Base64DecMap[Asc(ttscrambled.Substring(ttndx + 1, 1))];
 ttthird = Base64DecMap[Asc(ttscrambled.Substring(ttndx + 2, 1))];
 ttfourth = Base64DecMap[Asc(ttscrambled.Substring(ttndx + 3, 1))];

 ttret = ttret + Convert.ToChar(((ttfirst * 4) & 255) + ((ttsecond / 16) & 3));
 ttret = ttret + Convert.ToChar(((ttsecond * 16) & 255) + ((ttthird / 4) & 15));
 ttret = ttret + Convert.ToChar(((ttthird * 64) & 255) + (ttfourth & 63));
 ttndx = ttndx + 4;
 }
 if (ttndx < ttrealLen)
 {
 ttfirst = Base64DecMap[Asc(ttscrambled.Substring(ttndx + 0, 1))];
 ttsecond = Base64DecMap[Asc(ttscrambled.Substring(ttndx + 1, 1))];
 ttret = ttret + Convert.ToChar(((ttfirst * 4) & 255) + ((ttsecond / 16) & 3));
 if (ttrealLen % 4 == 3)
 {
 ttthird = Base64DecMap[Asc(ttscrambled.Substring(ttndx + 2, 1))];
 ttret = ttret + Convert.ToChar(((ttsecond * 16) & 255) + ((ttthird / 4) & 15));
 }
 }

 return ttret;
 }

 /// <summary>
 /// 加密调用方法入口
 /// </summary>
 /// <param name="strCryptThis"></param>
 /// <returns></returns>
 public object EnCrypt(string strCryptThis)
 {
 dynamic strChar = null;
 dynamic iKeyChar = null;
 dynamic iStringChar = null;
 dynamic strEncrypted = null;
 dynamic I = null;
 dynamic leng = null;
 leng = strCryptThis.Length;

 for (I = 0; I < leng; I++)
 {
 iKeyChar = Asc(g_Key.Substring(I, 1));
 iStringChar = Asc(strCryptThis.Substring(I, 1));
 dynamic iCryptChar = iKeyChar ^ iStringChar;
 strEncrypted += Convert.ToChar(iCryptChar).ToString();
 }
 return strEncrypted;

 }

}