Extended remote file reader to handle extensionless image urls and querystring parameters for remote URLs

New properties for whitelist: <add url="http://maps.googleapis.com"
extensionLess="true" imageFormat="png" />
Sample URL for extensionless/paramter remote image:

http://localhost:49788/remote.axd?http://maps.googleapis.com/maps/api/staticmap?center=52.341055,7.125435&zoom=13&sensor=false&size=600x300&key=AIzaSyCMKi4DyRB2N-j-Sm3LpZkl6rSXWP_G5ZE?width=600
A 3rd querystring part (here: width=600) if the remote image url has url
parameters.

Former-commit-id: 894a5bf8053ff902b48ee23b35546e37e747f178

src/ImageProcessor.Web/NET45/Config/ImageProcessorConfig.cs

@@ -121,6 +121,17 @@ namespace ImageProcessor.Web.Config
             }
         }
 
+        /// <summary>
+        /// 
+        /// </summary>
+        public ImageSecuritySection.SafeUrl[] RemoteFileWhiteListExtensions
+        {
+            get
+            {
+                return GetImageSecuritySection().WhiteList.Cast<ImageSecuritySection.SafeUrl>().ToArray();
+            }
+        }
+
         /// <summary>
         /// Gets a value indicating whether the current application is allowed to download remote files.
         /// </summary>

src/ImageProcessor.Web/NET45/Config/ImageSecuritySection.cs

@@ -178,6 +178,22 @@ namespace ImageProcessor.Web.Config
 
                 set { this["url"] = value; }
             }
+
+            [ConfigurationProperty("extensionLess", DefaultValue = false, IsRequired = false)]
+            public bool ExtensionLess
+            {
+                get { return (bool)this["extensionLess"]; }
+
+                set { this["extensionLess"] = value; }
+            }
+
+            [ConfigurationProperty("imageFormat", DefaultValue = "", IsRequired = false)]
+            public string ImageFormat
+            {
+                get { return (string)this["imageFormat"]; }
+
+                set { this["imageFormat"] = value; }
+            }
         }
     }
 }

src/ImageProcessor.Web/NET45/Helpers/RemoteFile.cs

@@ -48,6 +48,11 @@ namespace ImageProcessor.Web.Helpers
         /// </summary>
         private static readonly Uri[] RemoteFileWhiteList = ImageProcessorConfig.Instance.RemoteFileWhiteList;
 
+        /// <summary>
+        /// The white-list of url[s] from which to download remote files.
+        /// </summary>
+        public static readonly ImageSecuritySection.SafeUrl[] RemoteFileWhiteListExtensions = ImageProcessorConfig.Instance.RemoteFileWhiteListExtensions;
+
         /// <summary>
         /// The length of time, in milliseconds, that a remote file download attempt can last before timing out.
         /// </summary>

src/ImageProcessor.Web/NET45/HttpModules/ImageProcessingModule.cs

@@ -5,6 +5,11 @@
 // </copyright>
 // -----------------------------------------------------------------------
 
+using System.Linq;
+using System.Security.Cryptography;
+using System.Security.Policy;
+using System.Text;
+
 namespace ImageProcessor.Web.HttpModules
 {
     #region Using
@@ -177,6 +182,10 @@ namespace ImageProcessor.Web.HttpModules
             string requestPath = string.Empty;
             string queryString = string.Empty;
 
+            bool validExtensionLessUrl = false;
+            string urlParameters = "";
+            string extensionLessExtension = "";
+
             if (isRemote)
             {
                 // We need to split the querystring to get the actual values we want.
@@ -194,10 +203,25 @@ namespace ImageProcessor.Web.HttpModules
 
                     requestPath = paths[0];
 
-                    if (paths.Length > 1)
+                    if (paths.Count() > 2)
+                    {
+                        queryString = paths[2];
+                        urlParameters = paths[1];
+                    }
+                    else if (paths.Length > 1)
                     {
                         queryString = paths[1];
                     }
+
+                    validExtensionLessUrl = RemoteFile.RemoteFileWhiteListExtensions.Any(
+                        x => x.ExtensionLess == true && requestPath.StartsWith(x.Url.AbsoluteUri));
+
+                    if (validExtensionLessUrl)
+                    {
+                        extensionLessExtension = RemoteFile.RemoteFileWhiteListExtensions.First(
+                        x => x.ExtensionLess == true && requestPath.StartsWith(x.Url.AbsoluteUri)).ImageFormat;
+
+                    }
                 }
             }
             else
@@ -207,11 +231,31 @@ namespace ImageProcessor.Web.HttpModules
             }
 
             // Only process requests that pass our sanitizing filter.
-            if (ImageUtils.IsValidImageExtension(requestPath) && !string.IsNullOrWhiteSpace(queryString))
+            if ((ImageUtils.IsValidImageExtension(requestPath) || validExtensionLessUrl ) && !string.IsNullOrWhiteSpace(queryString))
             {
                 string fullPath = string.Format("{0}?{1}", requestPath, queryString);
                 string imageName = Path.GetFileName(requestPath);
 
+                if (validExtensionLessUrl && !string.IsNullOrWhiteSpace(extensionLessExtension))
+                {
+                    fullPath = requestPath;
+
+                    if (!string.IsNullOrWhiteSpace(urlParameters))
+                    {
+                        //TODO: Add hash for querystring parameters    
+                        HashAlgorithm algorithm = MD5.Create();  // SHA1.Create()
+                        var hashCode = algorithm.ComputeHash(Encoding.UTF8.GetBytes(urlParameters));
+                        StringBuilder sb = new StringBuilder();
+                        foreach (byte b in hashCode)
+                            sb.Append(b.ToString("X2"));
+                        imageName += sb.ToString();
+                        fullPath += sb.ToString();
+                    }
+
+                    imageName += "." + extensionLessExtension;
+                    fullPath += extensionLessExtension + "?" + queryString;
+                }
+
                 // Create a new cache to help process and cache the request.
                 DiskCache cache = new DiskCache(request, requestPath, fullPath, imageName, isRemote);
 
@@ -251,7 +295,7 @@ namespace ImageProcessor.Web.HttpModules
                         {
                             if (isRemote)
                             {
-                                Uri uri = new Uri(requestPath);
+                                Uri uri = new Uri(requestPath + "?" + urlParameters);
 
                                 RemoteFile remoteFile = new RemoteFile(uri, false);