Validate File after Upload completed

[Kristian Kretschmer]

Hello,

i search for a method to validate the file, aber upload ist completed. Is a solution available to create something like a hashkey, before upload started and compare these hashkey with the uploaded file?

Thank you.

[Kristian Kretschmer]

Okay, here is my solution:

i added a FileHashKey Parameter on the FileUploadStarting Event

 

 

 

void RadUpload1_FileUploadStarting(object sender, Telerik.Windows.Controls.FileUploadStartingEventArgs e)
{

if (e.FileParameters.ContainsKey("FileHashKey"))
{
e.FileParameters["FileHashKey"] = MD5FileHash(e.SelectedFile.File);
}
else
{
e.FileParameters.Add("FileHashKey", MD5FileHash(e.SelectedFile.File));
}
}

a function to create the hashkey
i found a MD5CryptoServiceProvider implementation for silverlight here:
http://www.markharris.net.au/blog/2008/10/23/md5cryptoserviceprovider-for-silverlight/

 

private string MD5FileHash(FileInfo fiFile)
{
        try
        {
            FileStream FileCheck = fiFile.OpenRead();
            MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
            byte[] md5Hash = md5.ComputeHash(FileCheck);
            FileCheck.Close();
            FileCheck = null;
            string Berechnet = BitConverter.ToString(md5Hash).Replace("-", "").ToLower();
            md5Hash = null;
            return Berechnet;
        }
        catch (Exception)
        {
            return String.Empty;
        }
}

on serverside i compare the hashkeys in the 

GetAssociatedData() method

 

 

 

 

 

   

string HashKey = this.Request.Form["0_FileHashKey"];
string localHashKey = String.Empty;
if (HashKey != String.Empty)
{
    localHashKey = MD5FileHash(MYSERVERFILEPATHHERE);
}

 

 

if (HashKey != localHashKey)
{
//FILE IS CORRUPT
}

i think, that's a good way to validate the file is complete.

 

[Alex Fidanov]

Hi Kristian Kretschmer,

Thank you for sharing your solution with us. Please let us know if we can assist you with anything else on the matter.

Best wishes,
Alex Fidanov
the Telerik team