asp.net中字符串加密,解密函数小结

using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Text;

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

    private static string De(string strCookie, int type)
    {
        string str;
        if ((type % 2) == 0)
        {
            str = DeTransform1(strCookie);
        }
        else
        {
            str = DeTransform3(strCookie);
        }
        return Transform2(strCookie);
    }

    //转换字符(Reverse)
    public static string Decode(string str)
    {
        str = str.Replace("<br>", "\n");
        str = str.Replace("&gt;", ">");
        str = str.Replace("&lt;", "<");
        str = str.Replace("&nbsp;", " ");
        str = str.Replace("&quot;", "\"");
        return str;
    }

    //解密
    public static string Decrypt(string Passowrd)
    {
        return FormsAuthentication.Decrypt(Passowrd).Name.ToString();
    }

    //解密方式一
    public static string DeTransform1(string str)
    {
        int i = 0;
        StringBuilder sb = new StringBuilder();
        foreach (char a in str)
        {
            switch ((i % 6))
            {
                case 0:
                    sb.Append((char)(a - '\x0001'));
                    break;

                case 1:
                    sb.Append((char)(a - '\x0005'));
                    break;

                case 2:
                    sb.Append((char)(a - '\a'));
                    break;

                case 3:
                    sb.Append((char)(a - '\x0002'));
                    break;

                case 4:
                    sb.Append((char)(a - '\x0004'));
                    break;

                case 5:
                    sb.Append((char)(a - '\t'));
                    break;
            }
            i++;
        }
        return sb.ToString();
    }

    //加密方式三
    public static string DeTransform3(string str)
    {
        int i = 0;
        StringBuilder sb = new StringBuilder();
        foreach (char a in str)
        {
            switch ((i % 6))
            {
                case 0:
                    sb.Append((char)(a - '\x0003'));
                    break;

                case 1:
                    sb.Append((char)(a - '\x0006'));
                    break;

                case 2:
                    sb.Append((char)(a - '\b'));
                    break;

                case 3:
                    sb.Append((char)(a - '\a'));
                    break;

                case 4:
                    sb.Append((char)(a - '\x0005'));
                    break;

                case 5:
                    sb.Append((char)(a - '\x0002'));
                    break;
            }
            i++;
        }
        return sb.ToString();
    }

    private static string En(string strCookie, int type)
    {
        string str;
        if ((type % 2) == 0)
        {
            str = Transform1(strCookie);
        }
        else
        {
            str = Transform3(strCookie);
        }
        return Transform2(strCookie);
    }

    //转换字符
    public static string Encode(string str)
    {
        str = str.Replace("&", "&amp;");
        str = str.Replace("'", "''");
        str = str.Replace("\"", "&quot;");
        str = str.Replace(" ", "&nbsp;");
        str = str.Replace("<", "&lt;");
        str = str.Replace(">", "&gt;");
        str = str.Replace("\n", "<br>");
        return str;
    }

    //加密
    public static string Encrypt(string Password)
    {
        FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(Password, true, 2);
        return FormsAuthentication.Encrypt(ticket).ToString();
    }

    //SHA1加密,MD5加密
    public static string Encrypt(string Password, int Format)
    {
        switch (Format)
        {
            case 0:
                return FormsAuthentication.HashPasswordForStoringInConfigFile(Password, "SHA1");

            case 1:
                return FormsAuthentication.HashPasswordForStoringInConfigFile(Password, "MD5");
        }
        return "";
    }

    public static string EncryptCookie(string strCookie, int type)
    {
        string str = En(strCookie, type);
        StringBuilder sb = new StringBuilder();
        foreach (char a in str)
        {
            sb.Append(Convert.ToString((int)a, 0x10).PadLeft(4, '0'));
        }
        return sb.ToString();
    }

    //反转字符
    public static string Reverse(string str)
    {
        StringBuilder sb = new StringBuilder();
        for (int i = str.Length - 1; i >= 0; i--)
        {
            sb.Append(str[i]);
        }
        return sb.ToString();
    }

    //解密方式一
    public static string Transform1(string str)
    {
        int i = 0;
        StringBuilder sb = new StringBuilder();
        foreach (char a in str)
        {
            switch ((i % 6))
            {
                case 0:
                    sb.Append((char)(a + '\x0001'));
                    break;

                case 1:
                    sb.Append((char)(a + '\x0005'));
                    break;

                case 2:
                    sb.Append((char)(a + '\a'));
                    break;

                case 3:
                    sb.Append((char)(a + '\x0002'));
                    break;

                case 4:
                    sb.Append((char)(a + '\x0004'));
                    break;

                case 5:
                    sb.Append((char)(a + '\t'));
                    break;
            }
            i++;
        }
        return sb.ToString();
    }

    public static string Transform2(string str)
    {
        uint j = 0;
        StringBuilder sb = new StringBuilder();
        str = Reverse(str);
        foreach (char a in str)
        {
            j = a;
            if (j > 0xff)
            {
                j = (uint)((a >> 8) + ((a & 0xff) << 8));
            }
            else
            {
                j = (uint)((a >> 4) + ((a & 15) << 4));
            }
            sb.Append((char)j);
        }
        return sb.ToString();
    }

    //解密方式三
    public static string Transform3(string str)
    {
        int i = 0;
        StringBuilder sb = new StringBuilder();
        foreach (char a in str)
        {
            switch ((i % 6))
            {
                case 0:
                    sb.Append((char)(a + '\x0003'));
                    break;

                case 1:
                    sb.Append((char)(a + '\x0006'));
                    break;

                case 2:
                    sb.Append((char)(a + '\b'));
                    break;

                case 3:
                    sb.Append((char)(a + '\a'));
                    break;

                case 4:
                    sb.Append((char)(a + '\x0005'));
                    break;

                case 5:
                    sb.Append((char)(a + '\x0002'));
                    break;
            }
            i++;
        }
        return sb.ToString();
    }

    public static string RandString()
    {
        string str = "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz~!@#$%^&*,.:;'";
        Random r = new Random();
        string result = string.Empty;

        for (int i = 0; i < 32; i++)
        {
            int m = r.Next(0, 76);
            string s = str.Substring(m, 1);
            result += s;
        }

        return result;
    }

    public static string DisGuise()
    {
        string str = "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
        Random r = new Random();
        string result = string.Empty;

        for (int i = 0; i < 32; i++)
        {
            int m = r.Next(0, 46);
            string s = str.Substring(m, 1);
            result += s;
        }

        return result;
    }
}