Asp.Net 加密解密

    #endregion


    #region 一个用hash实现的加密解密方法
    /// <summary>
    /// 加密
    /// </summary>
    /// <param name="src"></param>
    /// <returns></returns>
    public static string EncryptStrByHash(string src)
    {
        if (src.Length == 0)
        {
            return "";
        }
        byte[] HaKey = System.Text.Encoding.ASCII.GetBytes((src + "Test").ToCharArray());
        byte[] HaData = new byte[20];
        HMACSHA1 Hmac = new HMACSHA1(HaKey);
        CryptoStream cs = new CryptoStream(Stream.Null, Hmac, CryptoStreamMode.Write);
        try
        {
            cs.Write(HaData, 0, HaData.Length);
        }
        finally
        {
            cs.Close();
        }
        string HaResult = System.Convert.ToBase64String(Hmac.Hash).Substring(0, 16);
        byte[] RiKey = System.Text.Encoding.ASCII.GetBytes(HaResult.ToCharArray());
        byte[] RiDataBuf = System.Text.Encoding.ASCII.GetBytes(src.ToCharArray());
        byte[] EncodedBytes =   { };
        MemoryStream ms = new MemoryStream();
        RijndaelManaged rv = new RijndaelManaged();
        cs = new CryptoStream(ms, rv.CreateEncryptor(RiKey, RiKey), CryptoStreamMode.Write);
        try
        {
            cs.Write(RiDataBuf, 0, RiDataBuf.Length);
            cs.FlushFinalBlock();
            EncodedBytes = ms.ToArray();
        }
        finally
        {
            ms.Close();
            cs.Close();
        }
        return HaResult + System.Convert.ToBase64String(EncodedBytes);
    }


    /// <summary>
    /// 解密
    /// </summary>
    /// <param name="src"></param>
    /// <returns></returns>
    public static string DecrypStrByHash(string src)
    {
        if (src.Length < 40) return "";
        byte[] SrcBytes = System.Convert.FromBase64String(src.Substring(16));
        byte[] RiKey = System.Text.Encoding.ASCII.GetBytes(src.Substring(0, 16).ToCharArray());
        byte[] InitialText = new byte[SrcBytes.Length];
        RijndaelManaged rv = new RijndaelManaged();
        MemoryStream ms = new MemoryStream(SrcBytes);
        CryptoStream cs = new CryptoStream(ms, rv.CreateDecryptor(RiKey, RiKey), CryptoStreamMode.Read);
        try
        {
            cs.Read(InitialText, 0, InitialText.Length);
        }
        finally
        {
            ms.Close();
            cs.Close();
        }
        System.Text.StringBuilder Result = new System.Text.StringBuilder();
        for (int i = 0; i < InitialText.Length; ++i) if (InitialText[i] > 0) Result.Append((char)InitialText[i]);
        return Result.ToString();
    }


    /// <summary>
    /// 对加密后的密文重新编码,如果密文长>16,则去掉前16个字符,如果长度小于16,返回空字符串
    /// </summary>
    /// <param name="s"></param>
    /// <returns></returns>
    public string ReEncryptStrByHash(string s)
    {
        string e = Encrypt.EncryptStrByHash(s);
        return ((e.Length > 16) ? e.Substring(16) : "");
    }
    #endregion


    #region Md5加密,生成16位或32位,生成的密文都是大写
    public static string Md5To16(string str)
    {
        MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
        string t2 = BitConverter.ToString(md5.ComputeHash(UTF8Encoding.Default.GetBytes(str)), 4, 8);
        t2 = t2.Replace("-", "");
        return t2;
    }


    //// <summary>
    /// MD5　32位加密
    /// </summary>
    /// <param name="str"></param>
    /// <returns></returns>
    public static string Md5To32(string str)
    {
        string pwd = "";
        MD5 md5 = MD5.Create();
        byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(str));
        for (int i = 0; i < s.Length; i++)
        {
            pwd = pwd + s[i].ToString("X");
        }
        return pwd;
    }
    #endregion


    #region 3DES加密解密
    public string Encrypt3DES(string str)
    {
        //密钥
        string sKey = "wyw308";
        //    //矢量,可为空
        string sIV = "scf521";
        //    //构造对称算法
        SymmetricAlgorithm mCSP = new TripleDESCryptoServiceProvider();


        ICryptoTransform ct;
        MemoryStream ms;
        CryptoStream cs;
        byte[] byt;
        mCSP.Key = Convert.FromBase64String(sKey);
        mCSP.IV = Convert.FromBase64String(sIV);
        mCSP.Mode = System.Security.Cryptography.CipherMode.ECB;
        mCSP.Padding = System.Security.Cryptography.PaddingMode.PKCS7;
        ct = mCSP.CreateEncryptor(mCSP.Key, mCSP.IV);
        byt = Encoding.UTF8.GetBytes(str);
        ms = new MemoryStream();
        cs = new CryptoStream(ms, ct, CryptoStreamMode.Write);
        cs.Write(byt, 0, byt.Length);
        cs.FlushFinalBlock();
        cs.Close();
        return Convert.ToBase64String(ms.ToArray());
    }
    /// <summary>
    /// 带指定密钥和矢量的3DES加密
    /// </summary>
    /// <param name="str"></param>
    /// <param name="sKey"></param>
    /// <param name="sIV"></param>
    /// <returns></returns>
    public string Encrypt3DES(string str, string sKey, string sIV)
    {
        SymmetricAlgorithm mCSP = new TripleDESCryptoServiceProvider();
        ICryptoTransform ct;
        MemoryStream ms;
        CryptoStream cs;
        byte[] byt;
        mCSP.Key = Convert.FromBase64String(sKey);
        mCSP.IV = Convert.FromBase64String(sIV);
        mCSP.Mode = System.Security.Cryptography.CipherMode.ECB;
        mCSP.Padding = System.Security.Cryptography.PaddingMode.PKCS7;
        ct = mCSP.CreateEncryptor(mCSP.Key, mCSP.IV);
        byt = Encoding.UTF8.GetBytes(str);
        ms = new MemoryStream();
        cs = new CryptoStream(ms, ct, CryptoStreamMode.Write);
        cs.Write(byt, 0, byt.Length);
        cs.FlushFinalBlock();
        cs.Close();
        return Convert.ToBase64String(ms.ToArray());
    }


    //解密
    public string Decrypt3DES(string Value)
    {
        string sKey = "wyw308";
        string sIV = "scf521";
        SymmetricAlgorithm mCSP = new TripleDESCryptoServiceProvider();
        ICryptoTransform ct;
        MemoryStream ms;
        CryptoStream cs;
        byte[] byt;
        mCSP.Key = Convert.FromBase64String(sKey);
        mCSP.IV = Convert.FromBase64String(sIV);
        mCSP.Mode = System.Security.Cryptography.CipherMode.ECB;
        mCSP.Padding = System.Security.Cryptography.PaddingMode.PKCS7;
        ct = mCSP.CreateDecryptor(mCSP.Key, mCSP.IV);
        byt = Convert.FromBase64String(Value);
        ms = new MemoryStream();
        cs = new CryptoStream(ms, ct, CryptoStreamMode.Write);
        cs.Write(byt, 0, byt.Length);
        cs.FlushFinalBlock();
        cs.Close();
        return Encoding.UTF8.GetString(ms.ToArray());
    }
    /// <summary>
    /// 带指定密钥和矢量的3DES解密
    /// </summary>
    /// <param name="Value"></param>
    /// <param name="sKey"></param>
    /// <param name="sIV"></param>
    /// <returns></returns>
    public string Decrypt3DES(string str, string sKey, string sIV)
    {
        SymmetricAlgorithm mCSP = new TripleDESCryptoServiceProvider();
        ICryptoTransform ct;
        MemoryStream ms;
        CryptoStream cs;
        byte[] byt;
        mCSP.Key = Convert.FromBase64String(sKey);
        mCSP.IV = Convert.FromBase64String(sIV);
        mCSP.Mode = System.Security.Cryptography.CipherMode.ECB;
        mCSP.Padding = System.Security.Cryptography.PaddingMode.PKCS7;
        ct = mCSP.CreateDecryptor(mCSP.Key, mCSP.IV);
        byt = Convert.FromBase64String(str);
        ms = new MemoryStream();
        cs = new CryptoStream(ms, ct, CryptoStreamMode.Write);
        cs.Write(byt, 0, byt.Length);
        cs.FlushFinalBlock();
        cs.Close();
        return Encoding.UTF8.GetString(ms.ToArray());
    }
    #endregion


    #region 一个简单的加密解密方法,只支持英文
    public static string EnCryptEnStr(string str) //倒序加1加密
    {
        byte[] by = new byte[str.Length];
        for (int i = 0;
         i <= str.Length - 1;
         i++)
        {
            by[i] = (byte)((byte)str[i] + 1);
        }
        str = "";
        for (int i = by.Length - 1;
         i >= 0;
         i--)
        {
            str += ((char)by[i]).ToString();
        }
        return str;
    }
    public static string DeCryptEnStr(string str) //顺序减1解码
    {
        byte[] by = new byte[str.Length];
        for (int i = 0;
         i <= str.Length - 1;
         i++)
        {
            by[i] = (byte)((byte)str[i] - 1);
        }
        str = "";
        for (int i = by.Length - 1;
         i >= 0;
         i--)
        {
            str += ((char)by[i]).ToString();
        }
        return str;
    }
    #endregion


    #region 一个简单的加密解密方法,在上一个的基础上支持中文
    public static string EnCryptCnStr(string str)
    {
        string htext = ""; // blank text


        for (int i = 0; i < str.Length; i++)
        {
            htext = htext + (char)(str[i] + 10 - 1 * 2);
        }
        return htext;
    }


    public static string DeCryptCnStr(string str)
    {
        string dtext = "";


        for (int i = 0; i < str.Length; i++)
        {
            dtext = dtext + (char)(str[i] - 10 + 1 * 2);
        }
        return dtext;
    }
    #endregion


    #region Url地址编码解码


    /// <summary>
    /// 编码Url地址
    /// </summary>
    /// <param name="url"></param>
    /// <returns></returns>
    public static string UrlEncode(string url)
    {
        byte[] mByte = null;
        mByte = System.Text.Encoding.GetEncoding("GB2312").GetBytes(url);


        return System.Web.HttpUtility.UrlEncode(mByte);
    }


    /// <summary>
    /// 解码Url地址
    /// </summary>
    /// <param name="url"></param>
    /// <returns></returns>
    public static string UrlDecode(string url)
    {
        return HttpUtility.UrlDecode(url, System.Text.Encoding.GetEncoding("GB2312"));
    }
    #endregion </pre>