Sikkerhedsretningslinjer

Oversigt

Dette dokument beskriver bedste praksis for sikkerhed for udvikling af XOOPS, der dækker inputvalidering, outputkodning, godkendelse, autorisation og beskyttelse mod almindelige websårbarheder.

Sikkerhedsprincipper

flowchart TB
    subgraph "Defense in Depth"
        A[Input Validation] --> B[Authentication]
        B --> C[Authorization]
        C --> D[Data Sanitization]
        D --> E[Output Encoding]
        E --> F[Audit Logging]
    end

Inputvalidering

Anmod om rensning

use Xoops\Core\Request;

// Always use typed getters
$id = Request::getInt('id', 0, 'GET');
$name = Request::getString('name', '', 'POST');
$email = Request::getEmail('email', '', 'POST');
$url = Request::getUrl('website', '', 'POST');

// Never use raw $_GET/$_POST/$_REQUEST
// Bad: $id = $_GET['id'];
// Good: $id = Request::getInt('id', 0, 'GET');

Valideringsregler

// Validate before use
if ($id <= 0) {
    throw new InvalidArgumentException('Invalid ID');
}

if (!preg_match('/^[a-zA-Z0-9_]{3,50}$/', $username)) {
    throw new InvalidArgumentException('Invalid username format');
}

// Use whitelist validation for enums
$allowedStatuses = ['draft', 'published', 'archived'];
if (!in_array($status, $allowedStatuses, true)) {
    throw new InvalidArgumentException('Invalid status');
}

SQL Forebyggelse af injektion

Brug parametrerede forespørgsler

// GOOD: Parameterized query
$sql = "SELECT * FROM {$xoopsDB->prefix('users')} WHERE uid = ?";
$result = $xoopsDB->query($sql, [$userId]);

// BAD: String concatenation (vulnerable!)
// $sql = "SELECT * FROM users WHERE uid = " . $userId;

Brug af kriterieobjekter

use Criteria;
use CriteriaCompo;

$criteria = new CriteriaCompo();
$criteria->add(new Criteria('status', 'published'));
$criteria->add(new Criteria('uid', $userId, '='));
$criteria->add(new Criteria('created', time() - 86400, '>'));

$articles = $articleHandler->getObjects($criteria);

XSS Forebyggelse

Udgangskodning

use Xoops\Core\Text\Sanitizer;

// HTML context
$safeName = htmlspecialchars($userName, ENT_QUOTES, 'UTF-8');

// In templates (auto-escaped)
{$userName|escape}

// For rich content
$sanitizer = Sanitizer::getInstance();
$safeContent = $sanitizer->sanitizeForDisplay($content);

Indholdssikkerhedspolitik

// Set CSP headers
header("Content-Security-Policy: default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'");

CSRF Beskyttelse

Token-implementering

// Generate token
use Xoops\Core\Security;

$token = Security::createToken();

// In form
echo '<input type="hidden" name="XOOPS_TOKEN_REQUEST" value="' . $token . '">';

// Verify on submission
if (!Security::checkToken()) {
    die('Security token mismatch');
}

Brug af XoopsForm

// Automatically adds CSRF token
$form = new XoopsThemeForm('Edit Article', 'articleform', 'save.php');
$form->addElement(new XoopsFormHiddenToken());

Godkendelse

Håndtering af adgangskode

// Hash passwords (PHP 5.5+)
$hashedPassword = password_hash($plainPassword, PASSWORD_ARGON2ID);

// Verify passwords
if (password_verify($plainPassword, $storedHash)) {
    // Password correct
}

// Check if rehash needed
if (password_needs_rehash($storedHash, PASSWORD_ARGON2ID)) {
    $newHash = password_hash($plainPassword, PASSWORD_ARGON2ID);
    // Update stored hash
}

Sessionssikkerhed

// Regenerate session ID after login
session_regenerate_id(true);

// Set secure session cookie options
ini_set('session.cookie_httponly', 1);
ini_set('session.cookie_secure', 1);
ini_set('session.cookie_samesite', 'Lax');

Autorisation

Tilladelsestjek

// Check module admin
if (!$xoopsUser || !$xoopsUser->isAdmin($xoopsModule->mid())) {
    redirect_header('index.php', 3, 'Access denied');
}

// Check group permissions
$grouppermHandler = xoops_getHandler('groupperm');
$groups = $xoopsUser ? $xoopsUser->getGroups() : [XOOPS_GROUP_ANONYMOUS];

if (!$grouppermHandler->checkRight('view_item', $itemId, $groups, $moduleId)) {
    throw new AccessDeniedException('Permission denied');
}

Rollebaseret adgang

class PermissionChecker
{
    public function canEdit(Article $article, ?XoopsUser $user): bool
    {
        if (!$user) {
            return false;
        }

        // Admin can edit anything
        if ($user->isAdmin()) {
            return true;
        }

        // Author can edit their own
        if ($article->getAuthorId() === $user->uid()) {
            return true;
        }

        // Check editor permission
        return $this->hasPermission($user, 'article_edit');
    }
}

Filoverførselssikkerhed

class SecureUploader
{
    private array $allowedMimeTypes = [
        'image/jpeg',
        'image/png',
        'image/gif'
    ];

    private array $allowedExtensions = ['jpg', 'jpeg', 'png', 'gif'];

    public function validate(array $file): bool
    {
        // Check file size
        if ($file['size'] > 2 * 1024 * 1024) {
            throw new FileTooLargeException();
        }

        // Verify MIME type
        $finfo = new finfo(FILEINFO_MIME_TYPE);
        $mimeType = $finfo->file($file['tmp_name']);

        if (!in_array($mimeType, $this->allowedMimeTypes, true)) {
            throw new InvalidFileTypeException();
        }

        // Check extension
        $extension = strtolower(pathinfo($file['name'], PATHINFO_EXTENSION));
        if (!in_array($extension, $this->allowedExtensions, true)) {
            throw new InvalidFileTypeException();
        }

        // Generate safe filename
        return true;
    }

    public function generateSafeFilename(string $original): string
    {
        $extension = strtolower(pathinfo($original, PATHINFO_EXTENSION));
        return bin2hex(random_bytes(16)) . '.' . $extension;
    }
}

Revisionslogning

class SecurityLogger
{
    public function logAuthAttempt(string $username, bool $success, string $ip): void
    {
        $data = [
            'username' => $username,
            'success' => $success,
            'ip' => $ip,
            'user_agent' => $_SERVER['HTTP_USER_AGENT'] ?? '',
            'timestamp' => time()
        ];

        // Log to database or file
        $this->log('auth', $data);
    }

    public function logSensitiveAction(int $userId, string $action, array $context): void
    {
        $data = [
            'user_id' => $userId,
            'action' => $action,
            'context' => json_encode($context),
            'ip' => $_SERVER['REMOTE_ADDR'],
            'timestamp' => time()
        ];

        $this->log('audit', $data);
    }
}

Sikkerhedsoverskrifter

// Recommended security headers
header('X-Content-Type-Options: nosniff');
header('X-Frame-Options: SAMEORIGIN');
header('X-XSS-Protection: 1; mode=block');
header('Referrer-Policy: strict-origin-when-cross-origin');
header('Permissions-Policy: geolocation=(), microphone=(), camera=()');

// HSTS (only for HTTPS sites)
if (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on') {
    header('Strict-Transport-Security: max-age=31536000; includeSubDomains');
}

Satsbegrænsende

class RateLimiter
{
    public function check(string $key, int $maxAttempts, int $windowSeconds): bool
    {
        $cacheKey = 'rate_limit:' . $key;
        $attempts = (int) $this->cache->get($cacheKey, 0);

        if ($attempts >= $maxAttempts) {
            return false; // Rate limited
        }

        $this->cache->increment($cacheKey, 1, $windowSeconds);
        return true;
    }
}

// Usage
$limiter = new RateLimiter();
if (!$limiter->check('login:' . $ip, 5, 300)) {
    throw new TooManyRequestsException('Too many login attempts');
}

Sikkerhedstjekliste

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