传递参数安全验证代码示例

在开发内部系统当中，我们经常使用参数进行传递，但由于明文传递会涉及到安全问题。所以我们一般都是加密明文再和明文一起传递，接受方再检测是否被明文是否中途被篡改。

表达不好，还是看代码吧！

上图是我对字符串加密和解密后的对照图。

下面是才是我调用的类：

/// <summary>
/// 对称加密处理类
/// </summary>
public class SymmCrypt
{
    private SymmetricAlgorithm mobjCryptoService;

    public enum SymmProvEnum
    {
        DES, RC2, Rijndael
    }

    public SymmCrypt()
    {
        this.mobjCryptoService = new DESCryptoServiceProvider();
    }

    /// <summary>
    /// 构造函数，选择加密方式
    /// </summary>
    /// <param name="encryptType"></param>
    public SymmCrypt(SymmProvEnum encryptType)
    {
        switch (encryptType)
        {
            case SymmProvEnum.DES:
                mobjCryptoService = new DESCryptoServiceProvider();
                break;
            case SymmProvEnum.RC2:
                mobjCryptoService = new RC2CryptoServiceProvider();
                break;
            case SymmProvEnum.Rijndael:
                mobjCryptoService = new RijndaelManaged();
                break;

        }
    }

    /// <summary>
    /// 利用MD5加密算法加密
    /// </summary>
    /// <param name="strIN">需要加密的字符串</param>
    /// <returns>返回加密过的字符串</returns>
    public static string MD5Encrypt(string strIN)
    {
        byte[] tmpByte;
        MD5 md5 = new MD5CryptoServiceProvider();
        tmpByte = md5.ComputeHash(GetBytesBySting(strIN));
        md5.Clear();
        return GetStringByBytes(tmpByte);

    }

    /// <summary>
    /// 利用SHA1加密算法加密
    /// </summary>
    /// <param name="strIN">需要加密的字符串</param>
    /// <returns>返回加密过的字符串</returns>
    public static string SHA1Encrypt(string strIN)
    {
        byte[] tmpByte;
        SHA1 sha1 = new SHA1CryptoServiceProvider();
        tmpByte = sha1.ComputeHash(GetBytesBySting(strIN));
        sha1.Clear();
        return GetStringByBytes(tmpByte);

    }

    /// <summary>
    /// 利用SHA256加密算法加密
    /// </summary>
    /// <param name="strIN">需要加密的字符串</param>
    /// <returns>返回加密过的字符串</returns>
    public static string SHA256Encrypt(string strIN)
    {
        byte[] tmpByte;
        SHA256 sha256 = new SHA256Managed();
        tmpByte = sha256.ComputeHash(GetBytesBySting(strIN));
        sha256.Clear();
        return GetStringByBytes(tmpByte);
    }

    /// <summary>
    /// 利用SHA512加密算法加密
    /// </summary>
    /// <param name="strIN">需要加密的字符串</param>
    /// <returns>返回加密过的字符串</returns>
    public static string SHA512Encrypt(string strIN)
    {
        byte[] tmpByte;
        SHA512 sha512 = new SHA512Managed();
        tmpByte = sha512.ComputeHash(GetBytesBySting(strIN));
        sha512.Clear();
        return GetStringByBytes(tmpByte);

    }

    #region Base64加密
    /// <summary>
    /// Base64加密
    /// </summary>
    /// <param name="text">要加密的字符串</param>
    /// <returns></returns>
    public static string EncodeBase64(string text)
    {
        //如果字符串为空，则返回
        if (string.IsNullOrEmpty(text))
        {
            return "";
        }

        try
        {
            char[] Base64Code = new char[]{'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T',
                                            'U','V','W','X','Y','Z','a','b','c','d','e','f','g','h','i','j','k','l','m','n',
                                            'o','p','q','r','s','t','u','v','w','x','y','z','0','1','2','3','4','5','6','7',
                                            '8','9','+','/','='};
            byte empty = (byte)0;
            ArrayList byteMessage = new ArrayList(Encoding.Default.GetBytes(text));
            StringBuilder outmessage;
            int messageLen = byteMessage.Count;
            int page = messageLen / 3;
            int use = 0;
            if ((use = messageLen % 3) > 0)
            {
                for (int i = 0; i < 3 - use; i++)
                    byteMessage.Add(empty);
                page++;
            }
            outmessage = new System.Text.StringBuilder(page * 4);
            for (int i = 0; i < page; i++)
            {
                byte[] instr = new byte[3];
                instr[0] = (byte)byteMessage[i * 3];
                instr[1] = (byte)byteMessage[i * 3 + 1];
                instr[2] = (byte)byteMessage[i * 3 + 2];
                int[] outstr = new int[4];
                outstr[0] = instr[0] >> 2;
                outstr[1] = ((instr[0] & 0x03) << 4) ^ (instr[1] >> 4);
                if (!instr[1].Equals(empty))
                    outstr[2] = ((instr[1] & 0x0f) << 2) ^ (instr[2] >> 6);
                else
                    outstr[2] = 64;
                if (!instr[2].Equals(empty))
                    outstr[3] = (instr[2] & 0x3f);
                else
                    outstr[3] = 64;
                outmessage.Append(Base64Code[outstr[0]]);
                outmessage.Append(Base64Code[outstr[1]]);
                outmessage.Append(Base64Code[outstr[2]]);
                outmessage.Append(Base64Code[outstr[3]]);
            }
            return outmessage.ToString();
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    #endregion

    #region Base64解密
    /// <summary>
    /// Base64解密
    /// </summary>
    /// <param name="text">要解密的字符串</param>
    public static string DecodeBase64(string text)
    {
        ////如果字符串为空，则返回
        //if (ValidationHelper.IsNullOrEmpty<string>(text))
        //{
        //    return "";
        //}

        //将空格替换为加号
        text = text.Replace(" ", "+");

        try
        {
            if ((text.Length % 4) != 0)
            {
                return "包含不正确的BASE64编码";
            }
            if (!Regex.IsMatch(text, "^[A-Z0-9/+=]*$", RegexOptions.IgnoreCase))
            {
                return "包含不正确的BASE64编码";
            }
            string Base64Code = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
            int page = text.Length / 4;
            ArrayList outMessage = new ArrayList(page * 3);
            char[] message = text.ToCharArray();
            for (int i = 0; i < page; i++)
            {
                byte[] instr = new byte[4];
                instr[0] = (byte)Base64Code.IndexOf(message[i * 4]);
                instr[1] = (byte)Base64Code.IndexOf(message[i * 4 + 1]);
                instr[2] = (byte)Base64Code.IndexOf(message[i * 4 + 2]);
                instr[3] = (byte)Base64Code.IndexOf(message[i * 4 + 3]);
                byte[] outstr = new byte[3];
                outstr[0] = (byte)((instr[0] << 2) ^ ((instr[1] & 0x30) >> 4));
                if (instr[2] != 64)
                {
                    outstr[1] = (byte)((instr[1] << 4) ^ ((instr[2] & 0x3c) >> 2));
                }
                else
                {
                    outstr[2] = 0;
                }
                if (instr[3] != 64)
                {
                    outstr[2] = (byte)((instr[2] << 6) ^ instr[3]);
                }
                else
                {
                    outstr[2] = 0;
                }
                outMessage.Add(outstr[0]);
                if (outstr[1] != 0)
                    outMessage.Add(outstr[1]);
                if (outstr[2] != 0)
                    outMessage.Add(outstr[2]);
            }
            byte[] outbyte = (byte[])outMessage.ToArray(Type.GetType("System.Byte"));
            return Encoding.Default.GetString(outbyte);
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    #endregion


    /// <summary>
    /// 把字节转换成字符串
    /// </summary>
    /// <param name="Byte">需要转换字节数组</param>
    /// <returns>转换后的字符串</returns>
    private static string GetStringByBytes(byte[] Byte)
    {
        string tmpString = "";
        //tmpString = UTF8Encoding.Default.GetString(Byte);
        tmpString = BitConverter.ToString(Byte);
        return tmpString;
    }

    /// <summary>
    /// 把字符串转换成字节数组
    /// </summary>
    /// <param name="strKey">需要转换的字符串</param>
    /// <returns>转换后的字节数组</returns>
    private static byte[] GetBytesBySting(string strKey)
    {
        int tmpStrLen = strKey.Length;
        byte[] tmpByte = new byte[tmpStrLen - 1];
        tmpByte = UTF8Encoding.Default.GetBytes(strKey);
        return tmpByte;
    }


    /// <summary>
    /// 获取Key的字节
    /// </summary>
    /// <param name="keyString">Key字符串</param>
    /// <returns>转换后的字节形式</returns>
    private byte[] GetKeyBytes(string keyString)
    {
        string sTemp = "";
        if (mobjCryptoService.LegalKeySizes.Length > 0)
        {
            int lessSize = 0;
            int moreSize = mobjCryptoService.LegalKeySizes[0].MinSize;
            while (keyString.Length * 8 > moreSize)
            {
                lessSize = moreSize;
                moreSize += mobjCryptoService.LegalKeySizes[0].SkipSize;
                System.Threading.Thread.Sleep(0);
            }
            sTemp = keyString.PadRight(moreSize / 8, '_');
        }
        else
            sTemp = keyString;
        return ASCIIEncoding.ASCII.GetBytes(sTemp);
    }

    /// <summary>
    /// 获取IV向量的字节
    /// </summary>
    /// <param name="ivString">IV向量字符串</param>
    /// <returns>转换后的字节形式</returns>
    private byte[] GetIvBytes(string ivString)
    {
        ivString += "diksk.sl";
        ivString = ivString.Substring(0, this.mobjCryptoService.IV.Length);
        return ASCIIEncoding.ASCII.GetBytes(ivString);
    }



    /// <summary>
    /// 对输入的字符串进行加密
    /// </summary>
    /// <param name="sourceString">需要加密的原始字符串</param>
    /// <param name="keyString">加密密钥</param>
    /// <param name="ivString">加密向量</param>
    /// <returns>加密后的字符串</returns>
    public string Encrypt(string sourceString, string keyString, string ivString)
    {
        byte[] data = Encoding.Default.GetBytes(sourceString);
        byte[] result;
        mobjCryptoService.Key = GetKeyBytes(keyString);
        mobjCryptoService.IV = GetIvBytes(ivString);
        ICryptoTransform desencrypt = mobjCryptoService.CreateEncryptor();
        result = desencrypt.TransformFinalBlock(data, 0, data.Length);
        string desString = "";
        for (int i = 0; i < result.Length; i++)
        {
            desString += result[i].ToString() + "-";
        }

        //return desString.TrimEnd('-');
        return BitConverter.ToString(result);
    }

    /// <summary>
    /// 对输入的密文字符串进行解密
    /// </summary>
    /// <param name="sourceString">需要解密的密文字符串</param>
    /// <param name="keyString">解密密钥</param>
    /// <param name="ivString">解密向量</param>
    /// <returns>解密后的原始字符串</returns>
    public string Decrypt(string sourceString, string keyString, string ivString)
    {
        try
        {
            string[] sInput = sourceString.Split("-".ToCharArray());
            byte[] data = new byte[sInput.Length];
            byte[] result;
            for (int i = 0; i < sInput.Length; i++)
                data[i] = byte.Parse(sInput[i], System.Globalization.NumberStyles.HexNumber);
            mobjCryptoService.Key = GetKeyBytes(keyString);
            mobjCryptoService.IV = GetIvBytes(ivString);
            ICryptoTransform desencrypt = mobjCryptoService.CreateDecryptor();
            result = desencrypt.TransformFinalBlock(data, 0, data.Length);
            return Encoding.Default.GetString(result);
        }
        catch
        {
            return "error";
        }
    }

    
}