DotNet隱藏敏感信息操作方法

    在項目中，有時候一些信息不便完全顯示，只需要顯示部分信息。現在提供一些隱藏敏感信息的操作方法，主要為對信息的截取操作：

     1.指定左右字符數量,中間的*的個數和實際長度有關：

        /// <summary>
        /// 隱藏敏感信息
        /// </summary>
        /// <param name="info">信息實體</param>
        /// <param name="left">左邊保留的字符數</param>
        /// <param name="right">右邊保留的字符數</param>
        /// <param name="basedOnLeft">當長度異常時，是否顯示左邊 
        /// <code>true</code>顯示左邊，<code>false</code>顯示右邊
        /// </param>
        /// <returns></returns>
        public static string HideSensitiveInfo(string info, int left, int right, bool basedOnLeft = true)
        {
            if (string.IsNullOrEmpty(info))
            {
                throw new ArgumentNullException(info);
            }
            var sbText = new StringBuilder();
            var hiddenCharCount = info.Length - left - right;
            if (hiddenCharCount > 0)
            {
                string prefix = info.Substring(0, left), suffix = info.Substring(info.Length - right);
                sbText.Append(prefix);
                for (var i = 0; i < hiddenCharCount; i++)
                {
                    sbText.Append("*");
                }
                sbText.Append(suffix);
            }
            else
            {
                if (basedOnLeft)
                {
                    if (info.Length > left && left > 0)
                    {
                        sbText.Append(info.Substring(0, left) + "****");
                    }
                    else
                    {
                        sbText.Append(info.Substring(0, 1) + "****");
                    }
                }
                else
                {
                    if (info.Length > right && right > 0)
                    {
                        sbText.Append("****" + info.Substring(info.Length - right));
                    }
                    else
                    {
                        sbText.Append("****" + info.Substring(info.Length - 1));
                    }
                }
            }
            return sbText.ToString();
        }

 2.指定左右字符數量,中間的*的個數固定：

        /// <summary>
        /// 隱藏敏感信息
        /// </summary>
        /// <param name="info">信息實體</param>
        /// <param name="left">左邊保留的字符數</param>
        /// <param name="right">右邊保留的字符數</param>
        /// <param name="basedOnLeft">當長度異常時，是否顯示左邊 
        /// <code>true</code>顯示左邊，<code>false</code>顯示右邊
        /// <returns></returns>
        public static string HideSensitiveInfo1(string info, int left, int right, bool basedOnLeft = true)
        {
            if (string.IsNullOrEmpty(info))
            {
                throw new ArgumentNullException(info);
            }
            var sbText = new StringBuilder();
            var hiddenCharCount = info.Length - left - right;
            if (hiddenCharCount > 0)
            {
                string prefix = info.Substring(0, left), suffix = info.Substring(info.Length - right);
                sbText.Append(prefix);
                sbText.Append("****");
                sbText.Append(suffix);
            }
            else
            {
                if (basedOnLeft)
                {
                    if (info.Length > left && left > 0)
                    {
                        sbText.Append(info.Substring(0, left) + "****");
                    }
                    else
                    {
                        sbText.Append(info.Substring(0, 1) + "****");
                    }
                }
                else
                {
                    if (info.Length > right && right > 0)
                    {
                        sbText.Append("****" + info.Substring(info.Length - right));
                    }
                    else
                    {
                        sbText.Append("****" + info.Substring(info.Length - 1));
                    }
                }
            }
            return sbText.ToString();
        }

3.“*”數量一定，設置為4個，按信息總長度的比例來取，默認左右各取1/3：

        /// <summary>
        /// 隱藏敏感信息
        /// </summary>
        /// <param name="info">信息</param>
        /// <param name="sublen">信息總長與左子串（或右子串）的比例</param>
        /// <param name="basedOnLeft"/>當長度異常時，是否顯示左邊，默認true，默認顯示左邊
        /// <code>true</code>顯示左邊，<code>false</code>顯示右邊
        /// <returns></returns>
        public static string HideSensitiveInfo(string info, int sublen = 3, bool basedOnLeft = true)
        {
            if (string.IsNullOrEmpty(info))
            {
                throw new ArgumentNullException(info);
            }
            if (sublen <= 1)
            {
                sublen = 3;
            }
            var subLength = info.Length / sublen;
            if (subLength > 0 && info.Length > (subLength * 2))
            {
                string prefix = info.Substring(0, subLength), suffix = info.Substring(info.Length - subLength);
                return prefix + "****" + suffix;
            }
            if (basedOnLeft)
            {
                var prefix = subLength > 0 ? info.Substring(0, subLength) : info.Substring(0, 1);
                return prefix + "****";
            }
            var suffixs = subLength > 0 ? info.Substring(info.Length - subLength) : info.Substring(info.Length - 1);
            return "****" + suffixs;
        }

 4.隱藏右鍵詳情

        /// <summary>
        /// 隱藏右鍵詳情
        /// </summary>
        /// <param name="email">郵件地址</param>
        /// <param name="left">郵件頭保留字符個數，默認值設置為3</param>
        /// <returns></returns>
        public static string HideEmailDetails(string email, int left = 3)
        {
            if (string.IsNullOrEmpty(email))
            {
                throw new ArgumentNullException(email);
            }
            if (!System.Text.RegularExpressions.Regex.IsMatch(email, @"\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"))
                return HideSensitiveInfo(email);
            var suffixLen = email.Length - email.LastIndexOf('@');
            return HideSensitiveInfo(email, left, suffixLen, false);
        }

  在一些信息的隱藏操作，可以采用js實現，也可以采用jquery插件完成操作，但是在前臺進行這樣的操作，存在一些風險，在后臺完成對字符的信息截取，可以很好的對信息進行保護。