Ensure Uploaded File Contents Cannot Be Recovered After Use?
Jan 18, 2011
I would like to make the contents of a file uploaded to a web server unrecoverable after it has been used. My concerns are:
When the file is uploaded, is it stored in a temporary directory (e.g. Windows Temp directory) and how do I clear all traces from there? Can the contents of the file be written to virtual memory and how do I ensure it is not or remove the contents once written? If I encrypt the file, would I still have to worry about the contents being saved to the Temp directory, virtual memory or elsewhere before the file was encrypted? Can I perform a secure delete in all the concerned about locations (temp, virtual memory, any others) and how do I do this? Are there any concerns I have missed or an alternate way to achieve the stated goal?
or some javascript code directly on the ascx page. everything works if i place this control somewhere in aspx markup. but if i add this control to the page dynamically to some UpdatePanel place holder on postback (this is logic i can not alter), control renders itself and then i get js error message, which says that functions which are placed in somefile.js are not defined/are null. Why is this happening ? Is there anyway to force js including in this case.
the code amount is huge and i was not able to provide a simplified example with the same error,.
The script is included but somehow the functions are not defined. I'm novice to js, so is it possible that just the script is included but not executed, so the functions are not declared ???
The interesting is that if on some page my custom control is declared in aspx.
I would like to use HTML input file type in my aspx page to allow user to browse for a excel file and then read the content of the excel sheet programmatically.If I want to read the excel sheet I need the full path of the file to connect to the excel sheet using asp.net.I do not understand how can I get the full path of the file.I know I can get the filename using postedFile.FileName property.But I need the full path of the file.
i am uploading a file through file upload control , file size has greater then 4 MB, I have to give the proper alert msg to the user that file size exceeding the limit.how to do it , because at server side it is crashed on the IIS and not return to the server to check the file size validation.that how it is possible to validate the file size and give the proper alert messege
I want to keep the uploaded file name to make it possible to users to download the file under the same name. But how can I implement it? The one option I see is to store each file to folder with unique name (GUID, for example).
I have a web form that uploads files by <asp:FileUpload> control. It uploads files to any folder on the disk (path to uploads can change in web.config, for example "c:UploadedFiles"). After file has been uploaded I need to show a link on the WebPage to download this file.
How it's possible create a link to this file (or what is another solution) on the web page if my website is in completely different place!?
I need to create a custom web control which will be a part of a class library. This custom web control implements the upload functionality. I have implemented this with a web user control where I have a fixed path to a page in the web project where the upload of files take place and it works just fine.
The created control in this class library is used in the web project. How do I post the uploaded file to a page, say SomeClass.cs, in the class library.
Actually i am trying to storing the uploaded file into database but when i run this codes:
[Code]....
I got this error: " Incorrect syntax near the keyword 'File'.Incorrect syntax near the keyword 'File'. " can anybody tell me why this error came out?I tried toi change my connection string in web config,but it still showing the same error each time i run it in my local.
how to prevent exe file from being uploaded in a website , even if exe file is inside zip file( exe file in a new folder and new folder is then zipped and uploaded)?
i'me developing an ASP.NET application and it includes a FileUpload control, an object to show content of a format and a button to do functions. I want that when I upload the file, it will be shown in the object and for this reason i want to know the method to get the URL of the uploaded file.
is there any method on showing the image for the uploaded video files which are in flv format? i saw all the video in youtube got show the image of the video. how to do it?
I was trying to copy file to ftp via in my asp.net application... I did it successfully, however; when I open the copied file it is empty, I checked the properties aswell and its showing 0kb.
I want to upload csv file and import the data into sql. but I cant do the import thing. The file is uploaded but it cannot be imported into sql. This is my code. Hope that someone can tell me what is the problem.
I wanted to customize/Restrict the File Uploader control as follows:
1. To restrict Users to not to upload some type of file like.exe
2. To restrict the user to a specific size limit.
I also wanted to be able to display appropriate messages to the user if the abover restrictions are violated.
Can I use the validations control to achieve the above goals. As I am already using these controls to display appropriate messages to the user in case of wrong/invalid data.
I have made a document uploading page, In which use can upload their document. I am saving three fields in the database,
Document Name [NVarchar] File [Image] DocumentType [NVarchar]
Now, I am able to add records in the database, successfully. Now I want to show it in the gridview, like DocumentName, DocumentType and a link to download the file.
I have tried by retrieving the records and assigning them to the gridview but I am getting only two columns.
I have an ASP.NET FileUpload control, which allows only image type. I used RegularExpressionValidator like below.
<asp:FileUpload ID="fuPhoto" runat="server" TabIndex="40" /> <asp:RegularExpressionValidator ID="RegularExpressionValidator3" runat="server" ControlToValidate="fuPhoto" Display="Dynamic" ErrorMessage="* You can only upload .jpg, .gif or .png image types." ValidationExpression="^.*.(jpg|JPG|jpeg|JPEG|gif|GIF|png|PNG)$">* You can only upload .jpg, .gif or .png image types.</asp:RegularExpressionValidator>
This method will only verify the file's extension, not its actual type. Once I receive the file, I want to examine its contents to determine what it really is, in this case image only.
I have a page set up that allows users to upload files to the server, and then uses a database entry to attach the file to a project. When the project opens, I load a gridview with the list of files, and create a hyperlink to the file like this:
Code: Protected Sub gvFiles_RowDataBound(sender As Object, e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles gvFiles.RowDataBound If e.Row.RowType = DataControlRowType.DataRow Then ' Dim oLinkButton As LinkButton = e.Row.FindControl("lbDescription") Dim oSQL As New clsSQL
[Code] .....
When I try to click on the link, and select Open file, I get the following error:
I notice the type is right here, but on the open screen it isn't:
It says Type compressed Zip Folder for some reason. What I am doing incorrectly?
I am writing a simple web page that users can upload an image file. After the file is uploaded, Users can fill up other question in the web page. then users click the submit button to register them and the file is uploaded previously is move to special folder and is saved there. Know i want to delete the uploaded file if the user upload the file but dont click the submit button and close the web page. because i dont need the file uploaded until the user is not registered.I use Session_End event but i dont know why it dont work.
