typo3-security-php84

name	typo3-security-php84
description	PHP 8.4 security considerations for TYPO3. New security features and potential vulnerabilities.
version	1.0.0
php_compatibility	8.4+
typo3_compatibility	13.0 - 14.x
related_skills	["typo3-security","php-modernization"]
triggers	["security php 8.4","php84 security"]

TYPO3 Security with PHP 8.4

Compatibility: PHP 8.4+, TYPO3 v13.x and v14.x

Related Skills:

• typo3-security - Main security guide
• php-modernization/SKILL-PHP84 - PHP 8.4 features

---

1. PHP 8.4 Security Benefits

Asymmetric Visibility for Encapsulation

<?php

declare(strict_types=1);

// Prevent external modification of sensitive data
final class UserSession
{
    public private(set) string $sessionId;
    public private(set) \DateTimeImmutable $createdAt;
    public private(set) bool $authenticated = false;

    public function authenticate(string $token): void
    {
        if ($this->validateToken($token)) {
            $this->authenticated = true;
        }
    }
}

// External code cannot bypass authentication
$session = new UserSession();
$session->authenticated = true; // ❌ Error!

Property Hooks for Input Validation

<?php

declare(strict_types=1);

final class ApiRequest
{
    public string $endpoint {
        set (string $value) {
            // Validate and sanitize on assignment
            if (!str_starts_with($value, '/api/')) {
                throw new \InvalidArgumentException('Invalid API endpoint');
            }
            $this->endpoint = $value;
        }
    }

    public array $parameters {
        set (array $value) {
            // Sanitize all parameters
            $this->parameters = array_map(
                fn($v) => is_string($v) ? htmlspecialchars($v, ENT_QUOTES) : $v,
                $value
            );
        }
    }
}

---

2. Security Patterns with New Features

Readonly for Immutable Security Objects

<?php

declare(strict_types=1);

final readonly class SecurityContext
{
    public function __construct(
        public string $userId,
        public array $permissions,
        public \DateTimeImmutable $validUntil,
    ) {}

    public function hasPermission(string $permission): bool
    {
        return in_array($permission, $this->permissions, true);
    }
}

Using array_all() for Permission Checks

<?php

declare(strict_types=1);

final class PermissionChecker
{
    /**
     * @param string[] $requiredPermissions
     * @param string[] $userPermissions
     */
    public function hasAllPermissions(
        array $requiredPermissions,
        array $userPermissions
    ): bool {
        // PHP 8.4: Check all required permissions exist
        return array_all(
            $requiredPermissions,
            fn(string $perm) => in_array($perm, $userPermissions, true)
        );
    }

    /**
     * @param string[] $dangerousFlags
     */
    public function hasAnyDangerousFlag(array $userFlags, array $dangerousFlags): bool
    {
        return array_any(
            $userFlags,
            fn(string $flag) => in_array($flag, $dangerousFlags, )
        );
    }
}

---

3. Deprecation Awareness

Mark Insecure Methods

<?php

declare(strict_types=1);

final class AuthService
{
    #[\Deprecated(
        message: 'Use authenticateWithMFA() for secure authentication',
        since: '2.0.0'
    )]
    public function authenticateBasic(string $user, string $pass): bool
    {
        trigger_error(
            'authenticateBasic() is deprecated. Use MFA.',
            E_USER_DEPRECATED
        );
        return $this->authenticateWithMFA($user, $pass, '');
    }

    public function authenticateWithMFA(
        string $user,
        string $pass,
        string $mfaToken
    ): bool {
        // Secure implementation
    }
}

---

4. Security Checklist for PHP 8.4

• Use asymmetric visibility for sensitive properties
• Implement validation in property hooks
• Use readonly for immutable security contexts
• Mark legacy auth methods with #[\Deprecated]
• Update password hashing if needed
• Review session handling for PHP 8.4 changes

---

References

• typo3-security SKILL.md
• php-modernization SKILL-PHP84
• PHP 8.4 Release Notes

---

Credits & Attribution

This skill is part of the webconsulting.at TYPO3 skills collection.