add support for magnet file download links

src/Jackett.Common/Indexers/BaseIndexer.cs

@@ -286,6 +286,10 @@ namespace Jackett.Indexers
 
         protected async Task<byte[]> Download(Uri link, RequestType method)
         {
+            // return magnet link
+            if (link.Scheme == "magnet")
+                return Encoding.UTF8.GetBytes(link.OriginalString);
+
             // do some extra escaping, needed for HD-Torrents
             var requestLink = link.ToString()
                 .Replace("(", "%28")

src/Jackett.Common/Services/Interfaces/IServerService.cs

@@ -10,7 +10,7 @@ namespace Jackett.Services.Interfaces
         void Start();
         void Stop();
         void ReserveUrls(bool doInstall = true);
-        Uri ConvertToProxyLink(Uri link, string serverUrl, string indexerId, string action = "dl", string file = "t.torrent");
+        Uri ConvertToProxyLink(Uri link, string serverUrl, string indexerId, string action = "dl", string file = "t");
         string BasePath();
         string GetServerUrl(HttpRequestMessage Request);
         List<string> notices { get; } 

src/Jackett/Controllers/BlackholeController.cs

@@ -50,8 +50,23 @@ namespace Jackett.Controllers
                 path = Encoding.UTF8.GetString(HttpServerUtility.UrlTokenDecode(path));
                 path = protectionService.UnProtect(path);
                 var remoteFile = new Uri(path, UriKind.RelativeOrAbsolute);
+                var fileExtension = ".torrent";
                 var downloadBytes = await indexer.Download(remoteFile);
 
+                // handle magnet URLs
+                if (downloadBytes.Length >= 7
+                    && downloadBytes[0] == 0x6d // m
+                    && downloadBytes[1] == 0x61 // a
+                    && downloadBytes[2] == 0x67 // g
+                    && downloadBytes[3] == 0x6e // n
+                    && downloadBytes[4] == 0x65 // e
+                    && downloadBytes[5] == 0x74 // t
+                    && downloadBytes[6] == 0x3a // :
+                    )
+                {
+                    fileExtension = ".magnet";
+                }
+
                 if (string.IsNullOrWhiteSpace(serverConfig.BlackholeDir))
                 {
                     throw new Exception("Blackhole directory not set!");
@@ -64,9 +79,9 @@ namespace Jackett.Controllers
 
                 var fileName = DateTime.Now.Ticks.ToString() + "-" + StringUtil.MakeValidFileName(indexer.DisplayName, '_', false);
                 if (string.IsNullOrWhiteSpace(file))
-                    fileName += ".torrent";
+                    fileName += fileExtension;
                 else
-                    fileName += "-"+StringUtil.MakeValidFileName(file, '_', false); // call MakeValidFileName() again to avoid any possibility of path traversal attacks 
+                    fileName += "-"+StringUtil.MakeValidFileName(file + fileExtension, '_', false); // call MakeValidFileName() again to avoid any possibility of path traversal attacks 
 
                 File.WriteAllBytes(Path.Combine(serverConfig.BlackholeDir, fileName), downloadBytes);
                 jsonReply["result"] = "success";

src/Jackett/Controllers/DownloadController.cs

@@ -53,6 +53,23 @@ namespace Jackett.Controllers
                 var target = new Uri(path, UriKind.RelativeOrAbsolute);
                 var downloadBytes = await indexer.Download(target);
 
+                // handle magnet URLs
+                if (downloadBytes.Length >= 7
+                    && downloadBytes[0] == 0x6d // m
+                    && downloadBytes[1] == 0x61 // a
+                    && downloadBytes[2] == 0x67 // g
+                    && downloadBytes[3] == 0x6e // n
+                    && downloadBytes[4] == 0x65 // e
+                    && downloadBytes[5] == 0x74 // t
+                    && downloadBytes[6] == 0x3a // :
+                    )
+                {
+                    var magneturi = Encoding.UTF8.GetString(downloadBytes);
+                    var response = Request.CreateResponse(HttpStatusCode.Moved);
+                    response.Headers.Location = new Uri(magneturi);
+                    return response;
+                }
+
                 // This will fix torrents where the keys are not sorted, and thereby not supported by Sonarr.
                 var parser = new BencodeParser();
                 var torrentDictionary = parser.Parse(downloadBytes);
@@ -63,7 +80,7 @@ namespace Jackett.Controllers
                 result.Content.Headers.ContentType = new MediaTypeHeaderValue("application/x-bittorrent");
                 result.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
                 {
-                    FileName = StringUtil.MakeValidFileName(file, '_', false) // call MakeValidFileName again to avoid any kind of injection attack
+                    FileName = StringUtil.MakeValidFileName(file, '_', false) + ".torrent" // call MakeValidFileName again to avoid any kind of injection attack
                 };
                 return result;
             }

src/Jackett/Controllers/IndexerApiController.cs

@@ -156,7 +156,7 @@ namespace Jackett.Controllers.V20
             foreach (var result in results)
             {
                 var link = result.Link;
-                var file = StringUtil.MakeValidFileName(result.Title, '_', false) + ".torrent";
+                var file = StringUtil.MakeValidFileName(result.Title, '_', false);
                 result.Link = serverService.ConvertToProxyLink(link, serverUrl, result.TrackerId, "dl", file);
                 if (result.Link != null && result.Link.Scheme != "magnet" && !string.IsNullOrWhiteSpace(Engine.ServerConfig.BlackholeDir))
                     result.BlackholeLink = serverService.ConvertToProxyLink(link, serverUrl, result.TrackerId, "bh", file);

src/Jackett/Controllers/ResultsController.cs

@@ -319,7 +319,7 @@ namespace Jackett.Controllers.V20
 
             var proxiedReleases = result.Releases.Select(r => AutoMapper.Mapper.Map<ReleaseInfo>(r)).Select(r =>
             {
-                r.Link = serverService.ConvertToProxyLink(r.Link, serverUrl, r.Origin.ID, "dl", r.Title + ".torrent");
+                r.Link = serverService.ConvertToProxyLink(r.Link, serverUrl, r.Origin.ID, "dl", r.Title);
                 return r;
             });
 
@@ -371,7 +371,7 @@ namespace Jackett.Controllers.V20
             var potatoReleases = result.Releases.Where(r => r.Link != null || r.MagnetUri != null).Select(r =>
             {
                 var release = AutoMapper.Mapper.Map<ReleaseInfo>(r);
-                release.Link = serverService.ConvertToProxyLink(release.Link, serverUrl, CurrentIndexer.ID, "dl", release.Title + ".torrent");
+                release.Link = serverService.ConvertToProxyLink(release.Link, serverUrl, CurrentIndexer.ID, "dl", release.Title);
                 var item = new Models.DTO.TorrentPotatoResponseItem()
                 {
                     release_name = release.Title + "[" + CurrentIndexer.DisplayName + "]", // Suffix the indexer so we can see which tracker we are using in CPS as it just says torrentpotato >.>
@@ -403,7 +403,7 @@ namespace Jackett.Controllers.V20
             foreach (var result in results)
             {
                 var link = result.Link;
-                var file = StringUtil.MakeValidFileName(result.Title, '_', false) + ".torrent";
+                var file = StringUtil.MakeValidFileName(result.Title, '_', false);
                 result.Link = serverService.ConvertToProxyLink(link, serverUrl, result.TrackerId, "dl", file);
                 if (result.Link != null && result.Link.Scheme != "magnet" && !string.IsNullOrWhiteSpace(Engine.ServerConfig.BlackholeDir))
                     result.BlackholeLink = serverService.ConvertToProxyLink(link, serverUrl, result.TrackerId, "bh", file);

src/Jackett/Services/ServerService.cs

@@ -59,7 +59,7 @@ namespace Jackett.Services
             }
         }
 
-        public Uri ConvertToProxyLink(Uri link, string serverUrl, string indexerId, string action = "dl", string file = "t.torrent")
+        public Uri ConvertToProxyLink(Uri link, string serverUrl, string indexerId, string action = "dl", string file = "t")
         {
             if (link == null || (link.IsAbsoluteUri && link.Scheme == "magnet"))
                 return link;