.net 签名加密实现的一种简单方法

加密方法有很多，以下是其中一种简单的签名模式

1、首先客户端通过webapi按照IP地址，时间戳，随机数生成签名，并传递序列号

private Result_Sign Valid()
        {
            string ServerIP = "192.168.1.6";// HttpContext.Request.ServerVariables.Get("Local_Addr").ToString(); //地址
            string timestamp = DateTimeToStamp(DateTime.Now); //时间戳

            string nonce = ST.WEB.App_Start.Common.CreateValidateCode(6);//随机数
            string SignStr = SignatureString(ServerIP, timestamp, nonce);//生成签名
            string appseq = ConfigurationManager.AppSettings["DPSeq"]; //产品序列号
            string Url = string.Format("http://www.abc.com:89/api/Valid?signature={0}&timestamp={1}&nonce={2}&appseq={3}", SignStr, timestamp, nonce, appseq);//POST发送URL
           
            string resStr = ST.WEB.App_Start.Common.Get_Http(Url, 12000);
            Result_Sign resJson = new Result_Sign()
                {
                    code = "-1",
                    message = ""
                };
            if (resStr.Substring(0, 2) != "错误")
            {
                resJson = JsonConvert.DeserializeObject<Result_Sign>(resStr);
            }
            return resJson;
 }

 // DateTime时间格式转换为Unix时间戳格式
 private string DateTimeToStamp(DateTime time)
 {
      System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1));
       return ((int)(time - startTime).TotalSeconds).ToString();
 }

//生成签名串

 private string SignatureString(string appIP, string timestamp, string nonce)
 {
            string[] ArrTmp = { appIP, timestamp, nonce };

            Array.Sort(ArrTmp);
            string tmpStr = string.Join("", ArrTmp);

            tmpStr = FormsAuthentication.HashPasswordForStoringInConfigFile(tmpStr, "SHA1");
            return tmpStr.ToLower();
 }

//生成随机数

 public static string CreateValidateCode(int length)
{
            int[] randMembers = new int[length];
            int[] validateNums = new int[length];
            string validateNumberStr = "";
            //生成起始序列值
            int seekSeek = unchecked((int)DateTime.Now.Ticks);
            Random seekRand = new Random(seekSeek);
            int beginSeek = (int)seekRand.Next(0, Int32.MaxValue - length * 10000);
            int[] seeks = new int[length];
            for (int i = 0; i < length; i++)
            {
                beginSeek += 10000;
                seeks[i] = beginSeek;
            }
            //生成随机数字
            for (int i = 0; i < length; i++)
            {
                Random rand = new Random(seeks[i]);
                int pownum = 1 * (int)Math.Pow(10, length);
                randMembers[i] = rand.Next(pownum, Int32.MaxValue);
            }
            //抽取随机数字
            for (int i = 0; i < length; i++)
            {
                string numStr = randMembers[i].ToString();
                int numLength = numStr.Length;
                Random rand = new Random();
                int numPosition = rand.Next(0, numLength - 1);
                validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1));
            }
            for (int i = 0; i < length; i++)
            {
                validateNumberStr += validateNums[i].ToString();
            }
            return validateNumberStr;
 }

        /// <summary>
        /// 获取远程服务器ATN结果
        /// </summary>
        /// <param name="strUrl">指定URL路径地址</param>
        /// <param name="timeout">超时时间设置</param>
        /// <returns>服务器ATN结果</returns>
        public static string Get_Http(string strUrl, int timeout)
        {
            string strResult;
            try
            {
                HttpWebRequest myReq = (HttpWebRequest)HttpWebRequest.Create(strUrl);
                myReq.Timeout = timeout;
                HttpWebResponse HttpWResp = (HttpWebResponse)myReq.GetResponse();
                Stream myStream = HttpWResp.GetResponseStream();
                StreamReader sr = new StreamReader(myStream, Encoding.Default);
                StringBuilder strBuilder = new StringBuilder();
                while (-1 != sr.Peek())
                {
                    strBuilder.Append(sr.ReadLine());
                }
                strResult = strBuilder.ToString();
            }
            catch (Exception exp)
            {
                strResult = "错误：" + exp.Message;
            }
            return strResult;
        }
2、服务器端获取数据并验证返回结果

[HttpGet]
 public Result_Sign Sign(string signature, string timestamp, string nonce, string appseq)
 {
            Result_Sign sign = new Result_Sign()
            {
                  code="0",
                  message="fault"
            };
            if (Tool.ValidateSignature(signature, timestamp, nonce, appseq))
            {
                sign.code = "1";
                sign.message = "success";
            }
            return sign;

 }

        /// <summary>
        /// 检查应用接入的数据完整性
        /// </summary>
        /// <param name="signature">加密签名内容</param>
        /// <param name="timestamp">时间戳</param>
        /// <param name="nonce">随机字符串</param>
        /// <param name="appseq">序列号</param>
        /// <returns></returns>
        public static  bool ValidateSignature(string signature, string timestamp, string nonce, string appseq)
        {
            bool result = false;
            Register item = Cache.GetBySeq(appseq);//获取序列号相关信息
            if (item != null)
            {
                if (DateTime.Parse(item.ExpireDT) < DateTime.Now.Date) //是否过期
                {
                    return result;
                }
                #region 校验签名参数的来源是否正确
                string[] ArrTmp = { item.IP, timestamp, nonce };
                Array.Sort(ArrTmp);
                string tmpStr = string.Join("", ArrTmp);
                tmpStr = FormsAuthentication.HashPasswordForStoringInConfigFile(tmpStr, "SHA1");
                tmpStr = tmpStr.ToLower();
                if (tmpStr == signature && isNumberic(timestamp))
                { //验证成功
                    DateTime dtTime =  StampToDateTime(timestamp);
                    double minutes = DateTime.Now.Subtract(dtTime).TotalMinutes;
                    if (minutes < 5) //时间不能大于5分钟
                    {
                        result = true;
                    }
                }
                #endregion
            }
            return result;
}

 /// <summary>
 ///  时间戳转时间
 /// </summary>
/// <param name="timeStamp"></param>
/// <returns></returns>
 private static DateTime StampToDateTime(string timeStamp)
 {
            DateTime dateTimeStart = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1));
            long lTime = long.Parse(timeStamp + "0000000");
            TimeSpan toNow = new TimeSpan(lTime);
            return dateTimeStart.Add(toNow);
 }

/// <summary>
/// 是否为数字
 /// </summary>
 /// <param name="message"></param>
 /// <returns></returns>
 protected static bool isNumberic(string message)
 {
            System.Text.RegularExpressions.Regex rex =
            new System.Text.RegularExpressions.Regex(@"^\d+$");

            if (rex.IsMatch(message))
            {

                return true;
            }
            else
                return false;
 }

public class Result_Sign
{
        public string code { set; get; }
        public string message { set; get; }

}