strange issue when uploading file via asp.net, vs manually via FTP

Question

I have a form in ASP.Net MVC, which allows you to upload a file. The file is saved to a location on the server. For example, if the domain is www.test-domain.com, and the local path is c:\websites\test-domain.com\, the image is stored in /uploads/File/image.jpg.

When I try to access this url http://www.test-domain.com/uploads/File/image.jpg, I get redirected to the forms loginUrl="XXXX" path in web.config. To test, I removed the web.config entirely, and accessed the file. This time round, I get a 401 - Unauthorized: Access is denied due to invalid credentials.

I then uploaded another file via FTP this time, to http://www.test-domain.com/uploads/File/image2.jpg. This one can be accessed without any problem. I even tried download image.jpg as saved via Asp.Net, delete the file on server and re-upload the same exact file by FTP and it worked again!

It seems by FTP is working, while via Asp.Net somehow there are some access / authorisation requirement. I do have authentication set in Asp.Net, but I removed the entire web.config file, and I still got an error.

Any ideas?

Answer 1

I've found out why this was happening, though it is totally unrelated to what I thought it was in the beginning. I am uploading an image and resizing it. I've looked further in the code, and for some reason I was creating an image in the temporary windows folder, and then moving it to the actual location using File.Move.

It seems that the security permissions created are different, than if I had to create the file directly in the final folder. I've updated the code to create the image directly in the actual folder, and this is working fine.

Reference: http://blogs.msdn.com/b/oldnewthing/archive/2006/08/24/717181.aspx