Question

I’ve built a website with a HTML form/ PHP upload for image files, it works well when its running on XAMPP on my local computer but when i’ve uploaded it to 000webhost most of the time it says invalid file and only sometimes will the images successfully upload. I’ve tried turning up the max execution time in the php configuration but that doesn’t seem to have fixed it. The files i’ve tried to upload are smaller than the max file size in the php config and have worked on my test machine perfectly.

I find it odd that it works sometimes and doesn’t other times and don’t really know what to try.

EDIT:

Here is the form

Filename:

if ((($_FILES["file"]["type"] == "image/gif")
|| ($_FILES["file"]["type"] == "image/jpeg")
|| ($_FILES["file"]["type"] == "image/pjpeg")
|| ($_FILES["file"]["type"] == "image/png")))
   {
       if ($_FILES["file"]["error"] > 0)
          {
          echo "Return Code: " . $_FILES["file"]["error"] . "<br />";
          }
       else
          {
          echo "Upload: " . $_FILES["file"]["name"] . "<br />";
          echo "Type: " . $_FILES["file"]["type"] . "<br />";
          echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb<br />";
          echo "Temp file: " . $_FILES["file"]["tmp_name"] . "<br />";


          move_uploaded_file($_FILES["file"]["tmp_name"],
          "churchimages/pauls.jpeg");
          echo "Stored in: " . "churchimages/pauls.jpeg";

          }
  }

 else

 {
 echo "Invalid file";//This is the section I am seeing
 }

Answer 1

Your file type detection is relying on $_FILES["file"]["type"], which is sent by the browser and highly unreliable.

A much better way to detect whether an uploaded file is an image is getimagesize().

$info = getimagesize($_FILES["file"]["tmp_name"]);

$allowed_types = array(IMG_GIF, IMG_JPEG, IMG_PNG);

if (in_array($info[2], $allowed_types))
 { .... do stuff ... }