server/AyaNova/util/StringUtil.cs

@@ -0,0 +1,96 @@
+using System;
+
+namespace AyaNova.Util
+{
+
+
+    internal static class StringUtil
+    {
+
+        /// <summary>
+        /// Extract string between tokens
+        /// </summary>
+        /// <param name="s"></param>
+        /// <param name="openTag"></param>
+        /// <param name="closeTag"></param>
+        /// <returns></returns>
+        public static string Extract(string s, string openTag, string closeTag)
+        {
+            int startIndex = s.IndexOf(openTag);
+            if (startIndex == -1)
+                throw new System.IndexOutOfRangeException("ExtractString->Error: open tag not found");
+            startIndex += openTag.Length;
+
+            int endIndex = s.IndexOf(closeTag, startIndex);
+            if (endIndex == -1)
+                throw new System.IndexOutOfRangeException("ExtractString->Error: closing tag not found");
+            return s.Substring(startIndex, endIndex - startIndex);
+        }
+
+
+
+        /// <summary>
+        /// Trim a string if necessary
+        /// </summary>
+        /// <param name="s"></param>
+        /// <param name="maxLength"></param>
+        /// <returns></returns>
+        public static string MaxLength(string s, int maxLength)
+        {
+            if (s.Length > maxLength)
+                s = s.Substring(0, maxLength);
+            return s;
+        }
+
+
+        /// <summary>
+        /// mask the exact ip address by substituting the last position of the address with XXX
+        /// Works with v6 or v4 addresses as strings
+        /// </summary>
+        /// <param name="sIP"></param>
+        /// <returns></returns>
+        public static string MaskIPAddress(string sIP)
+        { 
+            //My test station ip address!?
+            //"::ffff:127.0.0.1"
+            //weird dual format, new method that covers both v4 and v4 inside v6 format
+            if(sIP.Contains("."))
+            {
+                //new algorithm, replace anything after last period with an xxx
+                var ret=sIP.Substring(0,sIP.LastIndexOf("."))+".xxx";
+                return ret;
+
+            }
+
+
+            //8 groups IPV6 Address format
+            if (sIP.Contains(":"))
+            {               
+               
+                sIP=sIP.Replace("::",":0:");//rehydrate "compressed" addresses
+                var segs = sIP.Split(':');
+                if (segs.Length < 7)
+                    return "UNRECOGNIZED V6 IP ADDRESS FORMAT";
+                else
+                    return segs[0] + ":" + segs[1] + ":" + segs[2] + ":" + segs[3] + ":" + segs[4] + ":" + segs[5] + ":" + segs[6] + ":" + segs[7] + ":xxxx";
+            }
+
+            // //4 groups IPV4 Address format
+            // if (sIP.Contains("."))
+            // {
+            //     //8 groups IPV6 Address format
+            //     var segs = sIP.Split('.');
+            //     if (segs.Length < 3)
+            //         return "UNRECOGNIZED V4 IP ADDRESS FORMAT";
+            //     else
+            //         return segs[0] + "." + segs[1] + "." + segs[2] + ".xxx";
+            // }
+
+            return "UNRECOGNIZED IP ADDDRESS FORMAT";
+        }
+
+
+
+    }//eoc
+
+}//eons