README

Slim 4 adapter for guard-core-php: wires the guard into Slim's middleware stack. It composes psr15-guard (the PSR-15 middleware adapter for the same engine) and adds the Slim-native integration layer: PSR-7 factory wiring from Slim's App, one-call attachment to the app or a route group, and the body-parsing ordering guidance. Works with Slim 4.

Docs: https://rennf93.github.io/slim-guard/

This package contains no security logic and no detection logic of its own. Every verdict comes from GuardEngine::execute(), and the fail-secure path (block translation, fail-closed 500) is inherited from psr15-guard, not reimplemented here.

Design: composition, not duplication

Slim 4 middleware IS PSR-15 middleware (psr/http-server-middleware), and psr15-guard already provides exactly that. slim-guard does not copy it. It requires psr15-guard and contributes only what is Slim-specific:

Factory wiring: SlimGuard::forApp($app, $engine) takes the ResponseFactoryInterface from Slim's App and resolves a matching StreamFactoryInterface (explicit argument, response factory that is also a stream factory, or the default slim/psr7 implementation when installed).
Attachment: addTo($app) calls Slim's App::add(); addToGroup($group) attaches to a route group with its documented semantics.
Ordering guidance for Slim's optional BodyParsingMiddleware, which consumes the request body stream.

The relationship is deliberate: slim-guard is the ecosystem's Slim flavor of the PSR-15 adapter, and psr15-guard remains the single place where guard verdicts become PSR-7 responses.

Install

composer require rennf93/slim-guard

Usage

Attach the guard where your Slim App is assembled:

use RenzoFranceschini\GuardCore\Config\SecurityConfig;
use RenzoFranceschini\GuardCore\Engine\GuardEngine;
use RenzoFranceschini\GuardCoreSlim\SlimGuard;
use Slim\Factory\AppFactory;

$app = AppFactory::create();

SlimGuard::forApp($app, new GuardEngine(new SecurityConfig(
    enableRedis: false,
    blacklist: ['192.0.2.0/24'],
    rateLimit: 100,
    rateLimitWindow: 60,
    enableRateLimiting: true,
)))->addTo($app);

Blocked requests get the engine's block verdict translated to a PSR-7 response by psr15-guard: 403 Forbidden for a blacklisted IP, 429 Too many requests with Retry-After for a rate limit hit. Passing requests continue into Slim's middleware stack untouched.

Lifecycle

PHP shared-nothing applies: construct GuardEngine per request in classic FPM, or per worker under long-running runtimes (FrankenPHP, RoadRunner, workerman). SlimGuard and the composed psr15-guard middleware hold no mutable state of their own. In-memory fallbacks are per-request safety nets; distributed rate limits, IP bans, and cloud-range caches require Redis (set enableRedis: true and point REDIS_HOST/REDIS_PORT at your instance).

Behavior notes

Fail-closed is inherited from psr15-guard: if the engine throws, the composed middleware returns the engine's fail-closed response (500 Security check failed, honorably overridden by customErrorResponses) instead of letting the request through.
Bounded body read is inherited from psr15-guard: the request body is scanned as a prefix of at most 256 KiB (matching the engine's full-scan window). Payloads beyond the prefix, or signatures split across its boundary, are not detected.
Middleware order matters: add the guard so it executes before any middleware that reads the request body stream (Slim's BodyParsingMiddleware casts the stream to a string, which leaves the read pointer at EOF). In Slim, the last middleware added executes first.
App-level attachment (addTo) screens everything that reaches the app, including unmatched routes that would 404. Group-level attachment (addToGroup) only screens requests that match a route inside the group; a blacklisted IP hitting an unmatched path under the group is answered by Slim's 404, not the guard's 403.
No security headers or CORS are added by this adapter or by psr15-guard; blocked responses are exact engine translations.

Testing

composer lint
composer test

composer test runs the plain-PHP suite in bin/test_slim.php (unit coverage always; set REDIS_HOST to a reachable Redis to include the shared-state integration cases).

Status

Released: v1.0.0 on Packagist. The engine, rennf93/guard-core-php, is at v4.0.4; the PSR-15 adapter it composes, rennf93/psr15-guard, is at v1.0.0.

License

MIT

rennf93 / slim-guard

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