Complete Secure Image Upload Script
Introduction
Ensuring secure image uploads is crucial for protecting your server and data. This script outlines a comprehensive approach to achieve maximum image upload security.
Step 1: File Type Validation
HTML Form:
<form action="upload.php" method="post" enctype="multipart/form-data">
<input type="file" name="image">
<input type="submit" name="upload" value="Upload">
</form>
PHP:
$allowedTypes = ['image/jpeg', 'image/png', 'image/gif'];
if (!in_array($_FILES['image']['type'], $allowedTypes)) {
echo "Invalid file type";
exit;
}
Step 2: Image Content Validation Using GD Library
$verifyimg = getimagesize($_FILES['image']['tmp_name']);
if ($verifyimg['mime'] != $_FILES['image']['type']) {
echo "Invalid image content";
exit;
}
Step 3: Restricted Upload Directory
Store uploaded images outside the accessible document root or in a protected directory:
/uploads
Step 4: Hiding File Information from Visitors
Rename and change the extension of uploaded images, and store the original information in a database:
PHP:
$uploadfile = tempnam_sfx($uploaddir, ".tmp");
if (move_uploaded_file($_FILES['image']['tmp_name'], $uploadfile)) {
// Database logic to store original name and MIME type
}
Step 5: Secure Image Retrieval
PHP:
$id = 1; // For example $sql = "SELECT name, original_name, mime_type FROM uploads WHERE>
Step 6: Additional Features
Maximum File Size Validation:
if ($_FILES['image']['size'] > 1000000) {
echo "File size too large";
exit;
}
ImageUpload Class:
I have created an ImageUpload class to simplify the upload process. Download the package and follow the README for instructions.
Open Source Availability:
The ImageUpload class is now available on GitHub for community contributions and improvements.
The above is the detailed content of How Can I Create a Secure Image Upload Script?. For more information, please follow other related articles on the PHP Chinese website!
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