加密和解密算法的兩個實現

     最近一段時間,集團加強了資安方面的管理,所有敏感的配置字節都必須經過加密處理,把最近用到的幾個加解密類整理了一下,以做備忘.

    其實這兩個類實現的方法差不多,只是有些細微區別:

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

/// <summary>
/// 對稱加密演算法類
/// </summary>
public class SymmetricMethodHelper
{
    private SymmetricAlgorithm mobjCryptoService;
    private string Key;
    /// <summary>
    /// 對稱加密類的構造函數
    /// </summary>
    public SymmetricMethodHelper()
    {
        mobjCryptoService = new RijndaelManaged();
        Key = "Guz(%&hj7x89H$yuBI0456FtmaT5&fvHUFCy76*h%(HilJ$lhj!y6&(*jkP87jH7";
    }

    /// <summary>
    /// 對稱加密類的構造函數
    /// </summary>
    public SymmetricMethodHelper(string key)
    {
        mobjCryptoService = new RijndaelManaged();
        Key = key + "Guz(%&hj7x89H$yuBI0456FtmaT5&fvHUFCy76*h%(HilJ$lhj!y6&(*jkP87jH7";
    }

    /// <summary>
    /// 獲得密鑰
    /// </summary>
    /// <returns>密鑰</returns>
    private byte[] GetLegalKey()
    {
        string sTemp = Key;
        mobjCryptoService.GenerateKey();
        byte[] bytTemp = mobjCryptoService.Key;
        int KeyLength = bytTemp.Length;
        if (sTemp.Length > KeyLength)
            sTemp = sTemp.Substring(0, KeyLength);
        else if (sTemp.Length < KeyLength)
            sTemp = sTemp.PadRight(KeyLength, ' ');
        return ASCIIEncoding.ASCII.GetBytes(sTemp);
    }
    /// <summary>
    /// 獲得初始向量IV
    /// </summary>
    /// <returns>初試向量IV</returns>
    private byte[] GetLegalIV()
    {
        string sTemp = "E4ghj*Ghg7!rNIfb&95GUY86GfghUb#er57HBh(u%g6HJ($jhWk7&!hg4ui%$hjk";
        mobjCryptoService.GenerateIV();
        byte[] bytTemp = mobjCryptoService.IV;
        int IVLength = bytTemp.Length;
        if (sTemp.Length > IVLength)
            sTemp = sTemp.Substring(0, IVLength);
        else if (sTemp.Length < IVLength)
            sTemp = sTemp.PadRight(IVLength, ' ');
        return ASCIIEncoding.ASCII.GetBytes(sTemp);
    }
    /// <summary>
    /// 加密方法
    /// </summary>
    /// <param name="Source">待加密的串</param>
    /// <returns>經過加密的串</returns>
    public string Encrypto(string Source)
    {
        byte[] bytIn = UTF8Encoding.UTF8.GetBytes(Source);
        MemoryStream ms = new MemoryStream();
        mobjCryptoService.Key = GetLegalKey();
        mobjCryptoService.IV = GetLegalIV();
        ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor();
        CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);
        cs.Write(bytIn, 0, bytIn.Length);
        cs.FlushFinalBlock();
        ms.Close();
        byte[] bytOut = ms.ToArray();
        return Convert.ToBase64String(bytOut);
    }
    /// <summary>
    /// 解密方法
    /// </summary>
    /// <param name="Source">待解密的串</param>
    /// <returns>經過解密的串</returns>
    public string Decrypto(string Source)
    {
        byte[] bytIn = Convert.FromBase64String(Source);
        MemoryStream ms = new MemoryStream(bytIn, 0, bytIn.Length);
        mobjCryptoService.Key = GetLegalKey();
        mobjCryptoService.IV = GetLegalIV();
        ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor();
        CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);
        StreamReader sr = new StreamReader(cs);
        return sr.ReadToEnd();
    }
}

 

 

using System;
using System.Text;
using System.IO;
using System.Security.Cryptography;

public class EncryptUtil {
        /// <summary>
        /// Des加密
        /// </summary>
        /// <param name="clearText"></param>
        /// <returns></returns>
        public static string DesEncrypt(string clearText) {
            byte[] byKey = System.Text.ASCIIEncoding.UTF8.GetBytes(KEY_64);
            byte[] byIV = System.Text.ASCIIEncoding.UTF8.GetBytes(IV_64);

            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();

            MemoryStream memStream = new MemoryStream();
            //以寫模式 把數據流和要加密的數據流建立連接
            CryptoStream cryStream = new CryptoStream(memStream, cryptoProvider.CreateEncryptor(byKey, byIV), CryptoStreamMode.Write);

            //將要加密的數據轉換為UTF8編碼的數組

            byte[] clearTextArray = Encoding.UTF8.GetBytes(clearText);

            //加密 並寫到 内存流memStream中

            cryStream.Write(clearTextArray, 0, clearTextArray.Length);
            //清空緩衝區
            cryStream.FlushFinalBlock();

            //將8位無符號整數數組 轉換為 等效的System.String 的形式.
            return Convert.ToBase64String(memStream.ToArray());
        }

        /// <summary>
        /// Des解密
        /// </summary>
        /// <param name="data"></param>
        /// <returns></returns>
        public static string DesDecrypt(string encryptedText) {
            byte[] byKey = System.Text.ASCIIEncoding.UTF8.GetBytes(KEY_64);
            byte[] byIV = System.Text.ASCIIEncoding.UTF8.GetBytes(IV_64);

            //
            byte[] byteArray = Convert.FromBase64String(encryptedText);

            MemoryStream memStream = new MemoryStream();

            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
            CryptoStream cryStream = new CryptoStream(memStream, cryptoProvider.CreateDecryptor(byKey, byIV), CryptoStreamMode.Write);

            cryStream.Write(byteArray, 0, byteArray.Length);
            //清空緩衝區
            cryStream.FlushFinalBlock();

            System.Text.Encoding encoding = new System.Text.UTF8Encoding();
            //把字節數組轉換為 等效的System.String 的形式.
            return encoding.GetString(memStream.ToArray());
        }


        /// <summary>
        /// Des加密,功能同DesEncrypt相同
        /// </summary>
        /// <param name="clearText"></param>
        /// <returns></returns>
        public static string DesEncode(string clearText) {
            byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
            byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);

            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();

            MemoryStream memStream = new MemoryStream();
            CryptoStream cryStream = new CryptoStream(memStream, cryptoProvider.CreateEncryptor(byKey, byIV), CryptoStreamMode.Write);

            StreamWriter sw = new StreamWriter(cryStream);
            sw.Write(clearText);
            sw.Flush();
            cryStream.FlushFinalBlock();
            sw.Flush();
            return Convert.ToBase64String(memStream.GetBuffer(), 0, (int)memStream.Length);

        }

        /// <summary>
        /// Des解密,功能同DesDecrypt相同
        /// </summary>
        /// <param name="encryptedText"></param>
        /// <returns></returns>
        public static string DesDecode(string encryptedText) {
            byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
            byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);

            byte[] byteArray;
            try {
                byteArray = Convert.FromBase64String(encryptedText);
            }
            catch {
                return null;
            }

            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
            MemoryStream memStream = new MemoryStream(byteArray);
            CryptoStream cryStream = new CryptoStream(memStream, cryptoProvider.CreateDecryptor(byKey, byIV), CryptoStreamMode.Read);
            StreamReader sr = new StreamReader(cryStream);
            
            return sr.ReadToEnd();
        }

        private const string KEY_64 = "MyPubKey";  //公鈅
        private const string IV_64 = "MyPriKey";   //私鈅,注意了:是8个字符，64位


    }

     注意這兩段代碼標注為紅色部分的差异,其中SymmetricMethodHelper類支持超過8位的私鑰,而EncryptUtil類不支持超過8位的私鑰.