What are the security considerations when using PHP scripts for file uploads and directory creation in a web application?

Issue: When allowing file uploads and directory creation in a web application using PHP scripts, it is important to consider security measures to prevent malicious files from being uploaded and executed on the server. One way to enhance security is to validate file types, limit file sizes, and restrict file permissions to prevent unauthorized access. 

// Validate file type before uploading
$allowedTypes = ['image/jpeg', 'image/png'];
if (!in_array($_FILES['file']['type'], $allowedTypes)) {
    die('Invalid file type. Only JPEG and PNG files are allowed.');
}

// Limit file size
$maxSize = 1048576; // 1MB
if ($_FILES['file']['size'] > $maxSize) {
    die('File size exceeds limit. Maximum size allowed is 1MB.');
}

// Set directory permissions
$uploadDir = 'uploads/';
if (!file_exists($uploadDir)) {
    mkdir($uploadDir, 0755, true);
}

// Move uploaded file to directory
$targetPath = $uploadDir . basename($_FILES['file']['name']);
if (move_uploaded_file($_FILES['file']['tmp_name'], $targetPath)) {
    echo 'File uploaded successfully.';
} else {
    echo 'Failed to upload file.';
}

Keywords

file uploads directory creation security considerations PHP scripts web application

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