Public Member Functions
	ImageUploadHelper (Config c)

string	GetExtension (string path)
	Parses the file extension from the path and returns it. If it contains a multi-segment extension like .txt.zip, only "zip" will be returned. More...

string	NormalizeExtension (string extension)
	Lowercases and normalizes some common extension aliases (jpeg->jpg, tiff-tif). Does not filter out non-image extensions! More...

bool	IsExtensionWhitelisted (string ext, string[] whitelistedFormats=null)
	Returns true if the given extension is whitelisted. More...

string	GetWhitelistedExtension (Stream image=null, string originalPath=null, string[] whitelistedFormats=null)
	Uses stream signatures first, then the original path, to detect the appropriate normalized image extension. Returns null if extension (or no whitelisted extension) is found. More...

bool	IsUploadedFileAnImage (object uploadFile, string[] whitelistedFormats=null)
	Returns true if the uploaded file is identified as an image (looks for the image signature, falling back to the user-provided filename). More...

int[]	GetImageSize (object s)
	Returns the [width,height] of the first frame/page of the image. May return null or throw exceptions. More...

string	SaveUploadedFileSafely (string baseDir, object uploadFile, string unrecognizedImageExtension=".unknown", string[] whitelistedFormats=null)
	Returns the name used for the file, without any path information. Name will be in "guid.ext" form. Will create any intermediate directories required. More...

string	GenerateSafeImageName (Stream image=null, string originalPath=null, string unrecognizedImageExtension=".unknown", string[] whitelistedFormats=null)
	Generates a safe name for your image in the form "guid.ext". Uses stream signatures first, then the path to determine the appropriate image extension. You can provide your own whitelist of extensions if desired; this defaults to the extensions supported by the currently installed set of plugins. More...

FileSignature	GuessFileTypeBySignature (Stream s)
	Tries to guess the file type of the given stream by the byte signature. Typically more reliable than file extensions - users constantly rename file extensions expecting it to change the actual encoding. Throws Argument exception if stream isn't seekable and readable. Returns null if there were no matches. Make sure the current position of the stream is at the beginning of the file, or you will get no results. Returns the stream to its original position More...

Properties
static ImageUploadHelper	Current `[get]`

Detailed Description

Definition at line 13 of file ImageUploadHelper.cs.

Member Function Documentation

string ImageResizer.ImageUploadHelper.GenerateSafeImageName	(	Stream	image = `null`,
		string	originalPath = `null`,
		string	unrecognizedImageExtension = `".unknown"`,
		string[]	whitelistedFormats = `null`
	)

inline

Generates a safe name for your image in the form "guid.ext". Uses stream signatures first, then the path to determine the appropriate image extension. You can provide your own whitelist of extensions if desired; this defaults to the extensions supported by the currently installed set of plugins.

Parameters

unrecognizedImageExtension Pass null to have an ArgumentException thrown if the image type is not recognized as a whitelisted format

Returns

Definition at line 188 of file ImageUploadHelper.cs.

Referenced by ImageResizer.ImageUploadHelper.SaveUploadedFileSafely().

         {   
             var ext = GetWhitelistedExtension(image,originalPath,whitelistedFormats) ?? unrecognizedImageExtension;
             if (ext == null) throw new ArgumentException("The provided image type is not recognized as a whitelisted format");
             return Guid.NewGuid().ToString("N", NumberFormatInfo.InvariantInfo) + ext;
         }

string ImageResizer.ImageUploadHelper.GetExtension ( string path )

inline

Parses the file extension from the path and returns it. If it contains a multi-segment extension like .txt.zip, only "zip" will be returned.

Parameters

path

Returns

Definition at line 30 of file ImageUploadHelper.cs.

Referenced by ImageResizer.ImageUploadHelper.GetWhitelistedExtension().

         {
             int lastDot = path.LastIndexOfAny(new char[] { '.', '/', ' ', '\\', '?', '&', ':' });
             if (lastDot > -1 && path[lastDot] == '.') return path.Substring(lastDot + 1);
             else return null;
         }

int [] ImageResizer.ImageUploadHelper.GetImageSize ( object s )

inline

Returns the [width,height] of the first frame/page of the image. May return null or throw exceptions.

Parameters

s	May be an UploadFile, a seekable Stream, a physical path, or a virtual path to the image.

Returns

Definition at line 139 of file ImageUploadHelper.cs.

                                            {
             var j = new ImageJob(s,null);
             j.ResetSourceStream = true;
             j.DisposeSourceObject = false;
             c.CurrentImageBuilder.Build(j);
             return new int[]{j.SourceWidth.Value,j.SourceHeight.Value};
         }

string ImageResizer.ImageUploadHelper.GetWhitelistedExtension	(	Stream	image = `null`,
		string	originalPath = `null`,
		string[]	whitelistedFormats = `null`
	)

inline

Uses stream signatures first, then the original path, to detect the appropriate normalized image extension. Returns null if extension (or no whitelisted extension) is found.

Parameters

image
originalPath
whitelistedFormats	You can provide your own whitelist of extensions if desired (new string[]{"jpg","png"}). This defaults to the extensions supported by the currently installed set of plugins.

Returns

Definition at line 90 of file ImageUploadHelper.cs.

Referenced by ImageResizer.ImageUploadHelper.GenerateSafeImageName(), and ImageResizer.ImageUploadHelper.IsUploadedFileAnImage().

         {   
             FileSignature sig = null;
             if (image != null && image.CanSeek && image.CanRead)
                 sig = GuessFileTypeBySignature(image);
 
             var sigExt = sig != null ? NormalizeExtension(sig.PrimaryFileExtension) : null;
 
             if (sigExt != null && IsExtensionWhitelisted(sigExt,whitelistedFormats)) return sigExt;
 
             //Falback to untrusted ppath
             if (originalPath != null){
                 string ext = NormalizeExtension(GetExtension(originalPath));
 
                 if (ext != null & IsExtensionWhitelisted(ext,whitelistedFormats)) return ext;
             }
             return null;
 
         }

FileSignature ImageResizer.ImageUploadHelper.GuessFileTypeBySignature ( Stream s )

inline

Tries to guess the file type of the given stream by the byte signature. Typically more reliable than file extensions - users constantly rename file extensions expecting it to change the actual encoding. Throws Argument exception if stream isn't seekable and readable. Returns null if there were no matches. Make sure the current position of the stream is at the beginning of the file, or you will get no results. Returns the stream to its original position

Parameters

s

Returns

Definition at line 203 of file ImageUploadHelper.cs.

Referenced by ImageResizer.ImageUploadHelper.GetWhitelistedExtension().

         {
             if (!(s.CanRead && s.CanSeek)) throw new ArgumentException("Stream must be seekable in order to guess the file type");
 
             List<FileSignature> signatures = new List<FileSignature>();
             foreach (var p in c.Plugins.GetAll<IFileSignatureProvider>())
                 signatures.AddRange(p.GetSignatures());
             
             if (signatures.Count == 0) return null; //No signatures to compare!!
 
             //Sort by length, longest first
             signatures.Sort(delegate(FileSignature a, FileSignature b){
                 return b.Signature.Length.CompareTo(a.Signature.Length);
             });
             //Copy the longest signature we may need to compare
             byte[] buffer = new byte[signatures[0].Signature.Length];
             int bytesRead = s.Read(buffer,0,buffer.Length);
             s.Seek(bytesRead, SeekOrigin.Current);
 
             foreach (var sig in signatures)
             {
                 if (bytesRead < sig.Signature.Length) continue; //Signature longer than file
                 if (sig.Signature.Length < 1) continue; //Empty signature
                 bool matches = true;
                 for (int i = 0; i < sig.Signature.Length; i++){
                     if (sig.Signature[i] != buffer[i])
                     {
                         matches = false;
                         break;
                     }
                 }
                 if (matches)
                 {
                     return sig;
                 }
             }
             return null;
         }

bool ImageResizer.ImageUploadHelper.IsExtensionWhitelisted	(	string	ext,
		string[]	whitelistedFormats = `null`
	)

inline

Returns true if the given extension is whitelisted.

Parameters

ext
whitelistedFormats	You can provide your own whitelist of extensions if desired (new string[]{"jpg","png"}). This defaults to the extensions supported by the currently installed set of plugins.

Returns

Definition at line 68 of file ImageUploadHelper.cs.

Referenced by ImageResizer.ImageUploadHelper.GetWhitelistedExtension().

         {
             if (whitelistedFormats == null)
                 return c.Pipeline.IsAcceptedImageType("." + ext);
             else
             {
                 foreach (var f in whitelistedFormats)
                 {
                     if (ext.Equals(f, StringComparison.OrdinalIgnoreCase)) return true;
                 }
                 return false;
             }
         }

bool ImageResizer.ImageUploadHelper.IsUploadedFileAnImage	(	object	uploadFile,
		string[]	whitelistedFormats = `null`
	)

inline

Returns true if the uploaded file is identified as an image (looks for the image signature, falling back to the user-provided filename).

Parameters

uploadFile	Must be an HttpPostedFile or another class with both FileName and InputStream members
whitelistedFormats	You can provide your own whitelist of extensions if desired (new string[]{"jpg","png"}). This defaults to the extensions supported by the currently installed set of plugins.

Returns

Definition at line 116 of file ImageUploadHelper.cs.

         {
             if (uploadFile == null) return false;
 
             PropertyInfo pname = uploadFile.GetType().GetProperty("FileName", typeof(string));
             PropertyInfo pstream = uploadFile.GetType().GetProperty("InputStream");
 
             if (pname != null && pstream != null)
             {
                 var path = pname.GetValue(uploadFile, null) as string;
                 var s = pstream.GetValue(uploadFile, null) as Stream;
                 if (s == null && path == null) throw new ArgumentException("The given upload file has a null .InputStream and .FileName");
 
                 return GetWhitelistedExtension(s, path, whitelistedFormats) != null;
             }
             return false;
         }

string ImageResizer.ImageUploadHelper.NormalizeExtension ( string extension )

inline

Lowercases and normalizes some common extension aliases (jpeg->jpg, tiff-tif). Does not filter out non-image extensions!

Parameters

path

Returns

Definition at line 42 of file ImageUploadHelper.cs.

Referenced by ImageResizer.ImageUploadHelper.GetWhitelistedExtension().

         {
             if (extension == null) return null;
             extension = extension.ToLowerInvariant();
   
             var mapping = new Dictionary<string,string>{
                 {"jpeg","jpg"},
                 {"jpe","jpg"},
                 {"jif","jpg"},
                 {"jfif","jpg"},
                 {"jfi","jpg"},
                 {"exif","jpg"},
                 {"tiff","tif"},
                 {"tff","tif"},
             };
 
             return mapping.ContainsKey(extension) ? mapping[extension] : extension;
         }

string ImageResizer.ImageUploadHelper.SaveUploadedFileSafely	(	string	baseDir,
		object	uploadFile,
		string	unrecognizedImageExtension = `".unknown"`,
		string[]	whitelistedFormats = `null`
	)

inline

Returns the name used for the file, without any path information. Name will be in "guid.ext" form. Will create any intermediate directories required.

Parameters

baseDir
uploadFile
unrecognizedImageExtension
whitelistedFormats

Returns

Definition at line 155 of file ImageUploadHelper.cs.

         {
             PropertyInfo pname = uploadFile.GetType().GetProperty("FileName", typeof(string));
             PropertyInfo pstream = uploadFile.GetType().GetProperty("InputStream");
 
             if (pname == null || pstream == null) throw new ArgumentException("uploadFile.InputStream and uploadFile.fileName are required. Ensure you are passing in an HttpPostedFile instance or similar");
             
             var uploadPath = pname.GetValue(uploadFile, null) as string;
             var uploadStream = pstream.GetValue(uploadFile, null) as Stream;
 
             var name = GenerateSafeImageName(uploadStream, uploadPath, unrecognizedImageExtension, whitelistedFormats);
 
             var dir = PathUtils.MapPathIfAppRelative(baseDir);
 
             var finalpath = Path.Combine(dir, name);
 
             string dirName = Path.GetDirectoryName(finalpath);
             if (!Directory.Exists(dirName)) Directory.CreateDirectory(dirName);
 
             using (var fileStream = new FileStream(finalpath, FileMode.Create))
             {
                 ImageResizer.ExtensionMethods.StreamExtensions.CopyToStream(uploadStream, fileStream);
                 fileStream.Flush();
             }
             return name;
         }

The documentation for this class was generated from the following file:

C:/Users/nathanael/Documents/resizer/Plugins/UploadHelper/ImageUploadHelper.cs

Public Member Functions

Properties

Detailed Description

Member Function Documentation