Merge pull request #2 from mrklintscher/master

Fix decipher

Author: LinPolly

YoutubeExtractor/ExampleApplication/Program.cs

@@ -89,7 +89,9 @@ private static void DownloadVideo(IEnumerable<VideoInfo> videoInfos)
         private static void Main()
         {
             // Our test youtube link
-            const string link = "https://www.youtube.com/watch?v=YQHsXMglC9A";
+            //const string link = "https://www.youtube.com/watch?v=D92-DmVmB8Y"; // -> needs deciphering
+
+            const string link = "https://www.youtube.com/watch?v=2a4Uxdy9TQY"; // -> needs no deciphering
 
             /*
              * Get the available video formats.

YoutubeExtractor/YoutubeExtractor/Decipherer.cs

@@ -13,7 +13,7 @@ public static string DecipherWithVersion(string cipher, string cipherVersion)
             string js = HttpHelper.DownloadString(jsUrl);
 
             //Find "yv" in this: c&&a.set(b,encodeURIComponent(yv(
-            string functNamePattern = @"\b[cs]\s*&&\s*[adf]\.set\([^,]+\s*,\s*encodeURIComponent\s*\(\s*([\w$]+)\("; //Regex Formed To Find Word or DollarSign
+            string functNamePattern = @"(\w+)=function\(\w+\){(\w+)=\2\.split\(\x22{2}\);.*?return\s+\2\.join\(\x22{2}\)}"; //Regex Formed To Find Word or DollarSign
 
             var funcName = Regex.Match(js, functNamePattern).Groups[1].Value;
 
@@ -22,7 +22,7 @@ public static string DecipherWithVersion(string cipher, string cipherVersion)
                 funcName = "\\" + funcName; //Due To Dollar Sign Introduction, Need To Escape
             }
 
-            string funcPattern = @"(?!h\.)" + @funcName + @"=function\(\w+\)\{.*?\}"; //Escape funcName string
+            string funcPattern = @"(?!h\.)" + @funcName + @"=function\(\w+\)\{(.*?)\}"; //Escape funcName string
             var funcBody = Regex.Match(js, funcPattern, RegexOptions.Singleline).Value; //Entire sig function
             var lines = funcBody.Split(';'); //Each line in sig function
 

YoutubeExtractor/YoutubeExtractor/DownloadUrlResolver.cs

@@ -187,13 +187,21 @@ private static IEnumerable<ExtractionInfo> ExtractDownloadUrls(JObject json)
                 if (queries.ContainsKey("s") || queries.ContainsKey("sig"))
                 {
                     requiresDecryption = queries.ContainsKey("s");
-                    string signature = queries.ContainsKey("s") ? queries["s"] : queries["sig"];
 
-                    url = string.Format("{0}&{1}={2}", queries["url"], SignatureQuery, signature);
+                    if (requiresDecryption)
+                    {
+                        string signature = queries.ContainsKey("s") ? queries["s"] : queries["sig"];
+
+                        url = string.Format("{0}&{1}={2}", queries["url"], SignatureQuery, signature);
 
-                    string fallbackHost = queries.ContainsKey("fallback_host") ? "&fallback_host=" + queries["fallback_host"] : String.Empty;
+                        string fallbackHost = queries.ContainsKey("fallback_host") ? "&fallback_host=" + queries["fallback_host"] : String.Empty;
 
-                    url += fallbackHost;
+                        url += fallbackHost;
+                    }
+                    else
+                    {
+                        url = NormalizeUrl(s);
+                    }
                 }
 
                 else
@@ -347,5 +355,10 @@ private class ExtractionInfo
 
             public Uri Uri { get; set; }
         }
+        
+        private static string NormalizeUrl(string url)
+        {
+            return url.Replace("\"", "").Replace("url=", "");
+        }
     }
 }