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Restrict file extensions?


luigimia

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Hi. I'm making a file-sharing website but how do I stop users from uploading certain extensions?

Here is my script so far:

 

<?php

session_start();

$file_name = $HTTP_POST_FILES['ufile']['name'];

$random_digit=rand(0000,9999);

$new_file_name=$random_digit.$file_name;

$path= "upload/".$new_file_name;

if($ufile !=none)

{

if(copy($HTTP_POST_FILES['ufile']['tmp_name'], $path))

{

echo "Successful<BR/>";

}

else

{

echo "Error";

}

}

?>

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you will want to the compare the mime of the file to the $_FILES[filename][type] value.

I like to store the valid extensions in an array and compare the array of values to the mime type of the given file using a conditional statement.

May you explain how to do that?

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I can't get this to work?

<?php 
$target = "upload/"; 
$target = $target . basename( $_FILES['uploaded']['name']) ; 
$ok=1; 

if ($uploaded_size > 350000) 
{ 
echo "Your file is too large.<br>"; 
$ok=0; 
} 
if (isset($uploaded_type) && $uploaded_type ==”text/php”)
{
echo “No PHP files”;
$ok=0;
}
if (isset($uploaded_type) && $uploaded_type ==”text/cgi”)
{
echo “Not an approved file type.”;
$ok=0;
}
if (isset($uploaded_type) && $uploaded_type ==”text/html”)
{
echo “Not an approved file type.”;
$ok=0;
}
if (isset($uploaded_type) && $uploaded_type ==”text/asp”)
{
echo “Not an approved file type.”;
$ok=0;
}
if (isset($uploaded_type) && $uploaded_type ==”text/pl”)
{
echo “Not an approved file type.”;
$ok=0;
}
if (isset($uploaded_type) && $uploaded_type ==”text/gif”)
{
echo “Not an approved file type.”;
$ok=0;
}
if (isset($uploaded_type) && $uploaded_type ==”text/jpg”)
{
echo “Not an approved file type.”;
$ok=0;
}
if (isset($uploaded_type) && $uploaded_type ==”text/png”)
{
echo “Not an approved file type.”;
$ok=0;
}
if (isset($uploaded_type) && $uploaded_type ==”text/tif”)
{
echo “Not an approved file type.”;
$ok=0;
}
if ($ok==0)
{
Echo “Sorry your file was not uploaded”;
}
else
{
if(move_uploaded_file($_FILES['uploaded']['tmp_name'], $target))
{
echo “The file “. basename( $_FILES['uploaded']['name']). ” has been uploaded”;
}
else
{
echo “Sorry, there was a problem uploading your file.”;
}
}
?>

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Try something like this, add any allowed mime types in the allowed array.

I also see the wrong type quotes in your code, try using an editor that does not convert quotes, notepad2 works great.

 

The proper double quote is ", not “ or ”

 

<html>
<body>

<form action="" method="post" enctype="multipart/form-data">
<label for="file">Filename:</label>
<input type="file" name="file" id="file" />
<br />
<input type="submit" name="submit" value="Submit" />
</form>

</body>
</html> 


<?php
if(isset($_POST['submit']) && !empty($_POST['submit'])) {
$allowed_array = array("image/gif","image/jpeg","image/pjpeg","image/png","image/bmp");
if ($_FILES["file"]["error"] > 0) {
  echo "Error: " . $_FILES["file"]["error"] . "<br />";
  } else {
  
if(in_array($_FILES["file"]["type"],$allowed_array)){  
  echo "Upload: " . $_FILES["file"]["name"] . "<br />";
  echo "Type: " . $_FILES["file"]["type"] . "<br />";
  echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb<br />";
  echo "Stored in: " . $_FILES["file"]["tmp_name"];
  } else {
  echo $_FILES["file"]["type"] . " not allowed";
  }
}

} else {
echo "Select your file to upload.";
}

?>

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Some changes to the previous code, also added checking for extensions within the allowed mime types.

 

<html>
<body>

<form action="" method="post" enctype="multipart/form-data">
<label for="file">Filename:</label>
<input type="file" name="file" id="file" />
<br />
<input type="submit" name="submit" value="Submit" />
</form>

</body>
</html> 


<?php
if(isset($_POST['submit']) && !empty($_FILES["file"]["name"])) {

$allowed_types = array("image/gif","image/jpeg","image/pjpeg","image/png","image/bmp");
$allowed_extensions = array("gif","png","jpg","bmp");

if ($_FILES["file"]["error"] > 0) {
  echo "Error: " . $_FILES["file"]["error"] . "<br />";
  } else {
  
$path_parts = pathinfo(strtolower($_FILES["file"]["name"]));
  
if(in_array($_FILES["file"]["type"],$allowed_types) && in_array($path_parts["extension"],$allowed_extensions)){  
  echo "Upload: " . $_FILES["file"]["name"] . "<br />";
  echo "Type: " . $_FILES["file"]["type"] . "<br />";
  $path_parts = pathinfo($_FILES["file"]["name"]);
  echo "Extension: " . $path_parts["extension"] . "<br />";
  echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb<br />";
  echo "Stored in: " . $_FILES["file"]["tmp_name"];
  } else {
  echo "Type " . $_FILES["file"]["type"] . "  with extension " . $path_parts["extension"] . " not allowed";
  }
}

} else {
echo "Select your file to upload.";
}

?>

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Some changes to the previous code, also added checking for extensions within the allowed mime types.

 

<html>
<body>

<form action="" method="post" enctype="multipart/form-data">
<label for="file">Filename:</label>
<input type="file" name="file" id="file" />
<br />
<input type="submit" name="submit" value="Submit" />
</form>

</body>
</html> 


<?php
if(isset($_POST['submit']) && !empty($_FILES["file"]["name"])) {

$allowed_types = array("image/gif","image/jpeg","image/pjpeg","image/png","image/bmp");
$allowed_extensions = array("gif","png","jpg","bmp");

if ($_FILES["file"]["error"] > 0) {
  echo "Error: " . $_FILES["file"]["error"] . "<br />";
  } else {
  
$path_parts = pathinfo(strtolower($_FILES["file"]["name"]));
  
if(in_array($_FILES["file"]["type"],$allowed_types) && in_array($path_parts["extension"],$allowed_extensions)){  
  echo "Upload: " . $_FILES["file"]["name"] . "<br />";
  echo "Type: " . $_FILES["file"]["type"] . "<br />";
  $path_parts = pathinfo($_FILES["file"]["name"]);
  echo "Extension: " . $path_parts["extension"] . "<br />";
  echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb<br />";
  echo "Stored in: " . $_FILES["file"]["tmp_name"];
  } else {
  echo "Type " . $_FILES["file"]["type"] . "  with extension " . $path_parts["extension"] . " not allowed";
  }
}

} else {
echo "Select your file to upload.";
}

?>

Thanks! Quick question though, where do I put your script in proportion to the original? I tried mingling it in but must have put it in the wrong place because some times I got it being treated as two different scripts and sometimes being presented with an error?

Where do I put the original?

 

Thanks!

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There seems to be items missing from that tutorial.

 

Don't foget to have a folder named upload in the same directory as this script is, or change your target path.

pretty sure I added the essentials to this, also included a timestamp to the front of the file name so you don't have duplicate named files.

 

<html>
<body>

<form action="" method="post" enctype="multipart/form-data">
<label for="file">Filename:</label>
<input type="file" name="file" id="file" />
<br />
<input type="submit" name="submit" value="Submit" />
</form>

</body>
</html> 


<?php
if(isset($_POST['submit']) && !empty($_FILES["file"]["name"])) {
$timestamp = time();
$target = "upload/"; 
$target = $target . basename($_FILES['uploaded']['name']) ; 
$ok=1;

$allowed_types = array("image/gif","image/jpeg","image/pjpeg","image/png","image/bmp");
$allowed_extensions = array("gif","png","jpg","bmp");

if ($_FILES['file']['size'] > 350000) {
$max_size =  round(350000 / 1024);
echo "Your file is too large. Maximum $max_size Kb is allowed. <br>"; 
$ok=0;
} 

if ($_FILES["file"]["error"] > 0) {
echo "Error: " . $_FILES["file"]["error"] . "<br />";
$ok=0;
} else {
  
$path_parts = pathinfo(strtolower($_FILES["file"]["name"]));
  
if(in_array($_FILES["file"]["type"],$allowed_types) && in_array($path_parts["extension"],$allowed_extensions)){
$filename = $timestamp."-".$_FILES["file"]["name"]; 
  echo "Name: " . $filename . "<br />";
  echo "Type: " . $_FILES["file"]["type"] . "<br />";
  $path_parts = pathinfo($_FILES["file"]["name"]);
  echo "Extension: " . $path_parts["extension"] . "<br />";
  echo "Size: " . round($_FILES["file"]["size"] / 1024) . " Kb<br />";
  //echo "Stored in: " . $_FILES["file"]["tmp_name"]. " <br />";
  } else {
  echo "Type " . $_FILES["file"]["type"] . "  with extension " . $path_parts["extension"] . " not allowed <br />";
  $ok=0;
  }
}
if($ok == 1){
@move_uploaded_file($_FILES["file"]["tmp_name"], $target . $filename);
$file_location = $target . $filename;
if(file_exists($file_location)){
echo "Uploaded to <a href='$file_location'>$filename</a> <br />";
} else {
echo "There was a problem saving the file. <br />";
}

}
} else {
echo "Select your file to upload.";
}

?>

 

You can use the file types with if/else or a switch statement and display a resized image if was an image, a link if was a file, an embed if audio or video, etc....

I just made it a hyperlink for simplicity.

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There seems to be items missing from that tutorial.

 

Don't foget to have a folder named upload in the same directory as this script is, or change your target path.

pretty sure I added the essentials to this, also included a timestamp to the front of the file name so you don't have duplicate named files.

 

<html>
<body>

<form action="" method="post" enctype="multipart/form-data">
<label for="file">Filename:</label>
<input type="file" name="file" id="file" />
<br />
<input type="submit" name="submit" value="Submit" />
</form>

</body>
</html> 


<?php
if(isset($_POST['submit']) && !empty($_FILES["file"]["name"])) {
$timestamp = time();
$target = "upload/"; 
$target = $target . basename($_FILES['uploaded']['name']) ; 
$ok=1;

$allowed_types = array("image/gif","image/jpeg","image/pjpeg","image/png","image/bmp");
$allowed_extensions = array("gif","png","jpg","bmp");

if ($_FILES['file']['size'] > 350000) {
$max_size =  round(350000 / 1024);
echo "Your file is too large. Maximum $max_size Kb is allowed. <br>"; 
$ok=0;
} 

if ($_FILES["file"]["error"] > 0) {
echo "Error: " . $_FILES["file"]["error"] . "<br />";
$ok=0;
} else {
  
$path_parts = pathinfo(strtolower($_FILES["file"]["name"]));
  
if(in_array($_FILES["file"]["type"],$allowed_types) && in_array($path_parts["extension"],$allowed_extensions)){
$filename = $timestamp."-".$_FILES["file"]["name"]; 
  echo "Name: " . $filename . "<br />";
  echo "Type: " . $_FILES["file"]["type"] . "<br />";
  $path_parts = pathinfo($_FILES["file"]["name"]);
  echo "Extension: " . $path_parts["extension"] . "<br />";
  echo "Size: " . round($_FILES["file"]["size"] / 1024) . " Kb<br />";
  //echo "Stored in: " . $_FILES["file"]["tmp_name"]. " <br />";
  } else {
  echo "Type " . $_FILES["file"]["type"] . "  with extension " . $path_parts["extension"] . " not allowed <br />";
  $ok=0;
  }
}
if($ok == 1){
@move_uploaded_file($_FILES["file"]["tmp_name"], $target . $filename);
$file_location = $target . $filename;
if(file_exists($file_location)){
echo "Uploaded to <a href='$file_location'>$filename</a> <br />";
} else {
echo "There was a problem saving the file. <br />";
}

}
} else {
echo "Select your file to upload.";
}

?>

 

You can use the file types with if/else or a switch statement and display a resized image if was an image, a link if was a file, an embed if audio or video, etc....

I just made it a hyperlink for simplicity.

 

You are a life saver. Thank you very very very much.  :D

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