C# 加密算法

时间:2023-12-18 20:30:38
 public static class Common
    {
        #region MD5加密
        /// <summary>   
        /// MD5加密   
        /// </summary>   
        /// <param name="strSource">需要加密的字符串</param>   
        /// <returns>MD5加密后的字符串</returns>   
        public static string Md5Encrypt(string strSource)
        {
            //把字符串放到byte数组中   
            byte[] bytIn = System.Text.Encoding.Default.GetBytes(strSource);
            //建立加密对象的密钥和偏移量           
            byte[] iv = { 102, 16, 93, 156, 78, 4, 218, 32 };//定义偏移量   
            byte[] key = { 55, 103, 246, 79, 36, 99, 167, 3 };//定义密钥   
            //实例DES加密类   
            DESCryptoServiceProvider mobjCryptoService = new DESCryptoServiceProvider();
            mobjCryptoService.Key = iv;
            mobjCryptoService.IV = key;
            ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor();
            //实例MemoryStream流加密密文件   
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);
            cs.Write(bytIn, 0, bytIn.Length);
            cs.FlushFinalBlock();
            return System.Convert.ToBase64String(ms.ToArray());
        }
        /// <summary>   
        /// MD5解密   
        /// </summary>   
        /// <param name="Source">需要解密的字符串</param>   
        /// <returns>MD5解密后的字符串</returns>   
        public static string Md5Decrypt(string Source)
        {
            //将解密字符串转换成字节数组   
            byte[] bytIn = System.Convert.FromBase64String(Source);
            //给出解密的密钥和偏移量,密钥和偏移量必须与加密时的密钥和偏移量相同   
            byte[] iv = { 102, 16, 93, 156, 78, 4, 218, 32 };//定义偏移量   
            byte[] key = { 55, 103, 246, 79, 36, 99, 167, 3 };//定义密钥   
            DESCryptoServiceProvider mobjCryptoService = new DESCryptoServiceProvider();
            mobjCryptoService.Key = iv;
            mobjCryptoService.IV = key;
            //实例流进行解密   
            System.IO.MemoryStream ms = new System.IO.MemoryStream(bytIn, 0, bytIn.Length);
            ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor();
            CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);
            StreamReader strd = new StreamReader(cs, Encoding.Default);
            return strd.ReadToEnd();
        }
        #endregion
        #region 动态加密
        private static byte[] s_bytKey;
        static Common()
        {
            s_bytKey = new byte[] { 0xa1, 0xb2, 0xc3, 0xd4, 0xe5, 0x16, 0x27, 0x38, 0x49, 80, 0x61, 0x72, 0x83, 0x94, 0xa5, 0xb6 };
        }
        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="text"></param>
        /// <param name="key"></param>
        /// <returns></returns>
        public static string PutBykey(string text, string key)
        {
            byte[] buffer = new byte[text.Length];
            byte[] bytes = Encoding.UTF8.GetBytes(Dscf.Global.Common.Common.DisposeId(key));
            RijndaelManaged managed = new RijndaelManaged();
            buffer = Convert.FromBase64String(text);
            MemoryStream stream = new MemoryStream();
            CryptoStream stream2 = new CryptoStream(stream, managed.CreateDecryptor(bytes, s_bytKey), CryptoStreamMode.Write);
            stream2.Write(buffer, 0, buffer.Length);
            stream2.FlushFinalBlock();
            Encoding encoding = new UTF8Encoding();
            return encoding.GetString(stream.ToArray());
        }
        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="text"></param>
        /// <param name="key"></param>
        /// <returns></returns>
        public static string GetByKey(string text, string key)
        {
            byte[] bytes = Encoding.UTF8.GetBytes(text);
            byte[] rgbKey = Encoding.UTF8.GetBytes(Dscf.Global.Common.Common.DisposeId(key));
            RijndaelManaged managed = new RijndaelManaged();
            MemoryStream stream = new MemoryStream();
            CryptoStream stream2 = new CryptoStream(stream, managed.CreateEncryptor(rgbKey, s_bytKey), CryptoStreamMode.Write);
            stream2.Write(bytes, 0, bytes.Length);
            stream2.FlushFinalBlock();
            return Convert.ToBase64String(stream.ToArray());
        }
        /// <summary>
        /// 处理Id,转变为加密key
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        public static string DisposeId(string id)
        {
            string strValue = "";
            for (int i = 0; i < 9 - id.Length; i++)
            {
                strValue += i;
            }
            return id.ToString() + strValue;
        }
        #endregion
    }