Merge pull request #7373 from dhensby/pulls/4/rate-limit-security

NEW RateLimiter for Security controller

_config/cache.yml

@@ -18,3 +18,7 @@ SilverStripe\Core\Injector\Injector:
       factory: SilverStripe\Core\Cache\CacheFactory
       constructor:
         namespace: "VersionProvider_composerlock"
+  Psr\SimpleCache\CacheInterface.RateLimiter:
+      factory: SilverStripe\Core\Cache\CacheFactory
+      constructor:
+        namespace: 'ratelimiter'

_config/modules.yml

@@ -21,7 +21,8 @@ SilverStripe\Core\Manifest\ModuleManifest:
     - $project
 ---
 Name: modules-framework
-After: modules-other
+After:
+  - '#modules-other'
 ---
 SilverStripe\Core\Manifest\ModuleManifest:
   module_priority:

_config/requestprocessors.yml

@@ -17,10 +17,22 @@ SilverStripe\Core\Injector\Injector:
   SilverStripe\Control\Middleware\TrustedProxyMiddleware:
     properties:
       TrustedProxyIPs: '`SS_TRUSTED_PROXY_IPS`'
+  SecurityRateLimitMiddleware:
+    class: SilverStripe\Control\Middleware\RateLimitMiddleware
+    properties:
+      ExtraKey: 'Security'
+      MaxAttempts: 10
+      Decay: 1
+  RateLimitedSecurityController:
+    class: SilverStripe\Control\Middleware\RequestHandlerMiddlewareAdapter
+    properties:
+      RequestHandler: '%$SilverStripe\Security\Security'
+      Middlewares:
+        - '%$SecurityRateLimitMiddleware'
 ---
 Name: errorrequestprocessors
 After:
-  - requestprocessors
+  - '#requestprocessors'
 ---
 SilverStripe\Core\Injector\Injector:
   # Note: If Director config changes, take note it will affect this config too

_config/routes.yml

@@ -18,3 +18,13 @@ SilverStripe\Control\Director:
     'InstallerTest//$Action/$ID/$OtherID': SilverStripe\Dev\InstallerTest
     'SapphireInfo//$Action/$ID/$OtherID': SilverStripe\Dev\SapphireInfo
     'SapphireREPL//$Action/$ID/$OtherID': SilverStripe\Dev\SapphireREPL
+---
+Name: security-limited
+After:
+  - '#rootroutes'
+Except:
+  environment: dev
+---
+SilverStripe\Control\Director:
+  rules:
+    'Security//$Action/$ID/$OtherID': '%$RateLimitedSecurityController'

_config/security.yml

@@ -19,7 +19,7 @@ SilverStripe\Core\Injector\Injector:
 ---
 Name: coresecurity
 After:
-  - requestprocessors
+  - '#requestprocessors'
 ---
 SilverStripe\Core\Injector\Injector:
   SilverStripe\Control\Director:

docs/en/02_Developer_Guides/09_Security/05_Rate_Limiting.md

@@ -0,0 +1,72 @@
+title: Rate Limiting
+summary: SilverStripe's in built rate limiting features
+
+# Rate Limiting
+
+SilverStripe Framework comes with a [Middleware](developer_guides/controllers/middlewares/) that provides rate limiting
+for the Security controller. This provides added protection to a potentially vulnerable part of a SilverStripe application
+where an attacker is free to bombard your login forms or other Security endpoints.
+
+## Applying rate limiting to controllers
+
+You can apply rate limiting to other specific controllers or your entire SilverStripe application. When applying rate
+limiting to other controllers you can define custom limits for each controller.
+
+First, you need to define your rate limit middleware with the required settings:
+
+```yml
+SilverStripe\Core\Injector\Injector:
+  MyRateLimitMiddleware:
+    class: SilverStripe\Control\Middleware\RateLimitMiddleware
+    properties:
+      ExtraKey: 'mylimiter' # this isolates your rate limiter from others
+      MaxAttempts: 10 # how many attempts are allowed in a decay period
+      Decay: 1 # how long the decay period is in minutes
+```
+
+Next, you need to define your request handler which will apply the middleware to the controller:
+
+```yml
+SilverStripe\Core\Injector\Injector:
+  MyRateLimitedController:
+    class: SilverStripe\Control\Middleware\RequestHandlerMiddlewareAdapter
+    properties:
+      RequestHandler: '%$MyController' # the fully qualified class name of your controller
+      Middlewares:
+        - '%$MyRateLimitMiddleware' # the rate limiter we just defined in the last step
+```
+
+Finally, you need to define the custom routing:
+
+```yml
+Director:
+  rules:
+    'MyController//$Action/$ID/$OtherID': '%$MyRateLimitedController'
+```
+
+## Applying rate limiting across an entire application
+
+If you'd like to add rate limiting to an entire application (ie: across all routes) then you'll need to define your rate
+limit middleware much like the first step outlined in the previous section and then you'll have to apply it to the entire
+site as you would with any other middleware:
+
+```yml
+SilverStripe\Core\Injector\Injector:
+  SilverStripe\Control\Director:
+    properties:
+      Middlewares:
+        SiteWideRateLimitMiddleware: '%$SiteWideRateLimitMiddleware'
+```
+
+## Disabling the Rate Limiter
+
+You may already solve the rate limiting problem on a server level and the built in rate limiting may well be redundant.
+If this is the case you can turn off the rate limiting middleware by redefining the URL rules for the Security controller.
+
+Add the following to your config.yml:
+
+```yml
+SilverStripe\Control\Director:
+  rules:
+    'Security//$Action/$ID/$OtherID': SilverStripe\Security\Security
+```

src/Control/HTTPRequest.php

@@ -774,6 +774,14 @@ class HTTPRequest implements ArrayAccess
         return sizeof($this->dirParts) <= $this->unshiftedButParsedParts;
     }
 
+    /**
+     * @return string Return the host from the request
+     */
+    public function getHost()
+    {
+        return $this->getHeader('host');
+    }
+
     /**
      * Returns the client IP address which originated this request.
      *

src/Control/Middleware/RateLimitMiddleware.php

@@ -0,0 +1,168 @@
+<?php
+
+namespace SilverStripe\Control\Middleware;
+
+use SilverStripe\Control\HTTPRequest;
+use SilverStripe\Control\HTTPResponse;
+use SilverStripe\Core\Cache\RateLimiter;
+use SilverStripe\ORM\FieldType\DBDatetime;
+use SilverStripe\Security\Security;
+
+class RateLimitMiddleware implements HTTPMiddleware
+{
+
+    /**
+     * @var string Optional extra data to add to request key generation
+     */
+    private $extraKey;
+
+    /**
+     * @var int Maximum number of attempts within the decay period
+     */
+    private $maxAttempts = 10;
+
+    /**
+     * @var int The decay period (in minutes)
+     */
+    private $decay = 1;
+
+    /**
+     * @var RateLimiter|null
+     */
+    private $rateLimiter;
+
+    /**
+     * @param HTTPRequest $request
+     * @param callable $delegate
+     * @return HTTPResponse
+     */
+    public function process(HTTPRequest $request, callable $delegate)
+    {
+        if (!$limiter = $this->getRateLimiter()) {
+            $limiter = RateLimiter::create(
+                $this->getKeyFromRequest($request),
+                $this->getMaxAttempts(),
+                $this->getDecay()
+            );
+        }
+        if ($limiter->canAccess()) {
+            $limiter->hit();
+            $response = $delegate($request);
+        } else {
+            $response = $this->getErrorHTTPResponse();
+        }
+        $this->addHeadersToResponse($response, $limiter);
+        return $response;
+    }
+
+    /**
+     * @param HTTPRequest $request
+     * @return string
+     */
+    protected function getKeyFromRequest($request)
+    {
+        $key = $this->getExtraKey() ? $this->getExtraKey() . '-' : '';
+        $key .= $request->getHost() . '-';
+        if ($currentUser = Security::getCurrentUser()) {
+            $key .= $currentUser->ID;
+        } else {
+            $key .= $request->getIP();
+        }
+        return md5($key);
+    }
+
+    /**
+     * @return HTTPResponse
+     */
+    protected function getErrorHTTPResponse()
+    {
+        return HTTPResponse::create('<h1>429 - Too many requests</h1>', 429);
+    }
+
+    /**
+     * @param HTTPResponse $response
+     * @param RateLimiter $limiter
+     */
+    protected function addHeadersToResponse($response, $limiter)
+    {
+        $response->addHeader('X-RateLimit-Limit', $limiter->getMaxAttempts());
+        $response->addHeader('X-RateLimit-Remaining', $remaining = $limiter->getNumAttemptsRemaining());
+        $ttl = $limiter->getTimeToReset();
+        $response->addHeader('X-RateLimit-Reset', DBDatetime::now()->getTimestamp() + $ttl);
+        if ($remaining <= 0) {
+            $response->addHeader('Retry-After', $ttl);
+        }
+    }
+
+    /**
+     * @param string $key
+     * @return $this
+     */
+    public function setExtraKey($key)
+    {
+        $this->extraKey = $key;
+        return $this;
+    }
+
+    /**
+     * @return string
+     */
+    public function getExtraKey()
+    {
+        return $this->extraKey;
+    }
+
+    /**
+     * @param int $maxAttempts
+     * @return $this
+     */
+    public function setMaxAttempts($maxAttempts)
+    {
+        $this->maxAttempts = $maxAttempts;
+        return $this;
+    }
+
+    /**
+     * @return int
+     */
+    public function getMaxAttempts()
+    {
+        return $this->maxAttempts;
+    }
+
+    /**
+     * @param int $decay Time in minutes
+     * @return $this
+     */
+    public function setDecay($decay)
+    {
+        $this->decay = $decay;
+        return $this;
+    }
+
+    /**
+     * @return int
+     */
+    public function getDecay()
+    {
+        return $this->decay;
+    }
+
+    /**
+     * @param RateLimiter $rateLimiter
+     * @return $this
+     */
+    public function setRateLimiter($rateLimiter)
+    {
+        $this->rateLimiter = $rateLimiter;
+        return $this;
+    }
+
+    /**
+     * @return RateLimiter|null
+     */
+    public function getRateLimiter()
+    {
+        return $this->rateLimiter;
+    }
+}

src/Core/Cache/RateLimiter.php

@@ -0,0 +1,193 @@
+<?php
+
+namespace SilverStripe\Core\Cache;
+
+use Psr\SimpleCache\CacheInterface;
+use SilverStripe\Core\Injector\Injectable;
+use SilverStripe\Core\Injector\Injector;
+use SilverStripe\ORM\FieldType\DBDatetime;
+
+class RateLimiter
+{
+    use Injectable;
+
+    /**
+     * @var CacheInterface
+     */
+    private $cache;
+
+    /**
+     * @var string
+     */
+    private $identifier;
+
+    /**
+     * @var int Maximum number of attempts allowed
+     */
+    private $maxAttempts;
+
+    /**
+     * @var int How long the rate limit lasts for in minutes
+     */
+    private $decay;
+
+    /**
+     * RateLimiter constructor.
+     * @param string $identifier
+     * @param int $maxAttempts
+     * @param int $decay
+     */
+    public function __construct($identifier, $maxAttempts, $decay)
+    {
+        $this->setIdentifier($identifier);
+        $this->setMaxAttempts($maxAttempts);
+        $this->setDecay($decay);
+    }
+
+    /**
+     * @return CacheInterface
+     */
+    public function getCache()
+    {
+        if (!$this->cache) {
+            $this->setCache(Injector::inst()->create(CacheInterface::class . '.RateLimiter'));
+        }
+        return $this->cache;
+    }
+
+    /**
+     * @param CacheInterface $cache
+     *
+     * @return $this
+     */
+    public function setCache($cache)
+    {
+        $this->cache = $cache;
+        return $this;
+    }
+
+    /**
+     * @return string
+     */
+    public function getIdentifier()
+    {
+        return $this->identifier;
+    }
+
+    /**
+     * @param string $identifier
+     * @return $this
+     */
+    public function setIdentifier($identifier)
+    {
+        $this->identifier = $identifier;
+        return $this;
+    }
+
+    /**
+     * @return int
+     */
+    public function getMaxAttempts()
+    {
+        return $this->maxAttempts;
+    }
+
+    /**
+     * @param int $maxAttempts
+     * @return $this
+     */
+    public function setMaxAttempts($maxAttempts)
+    {
+        $this->maxAttempts = $maxAttempts;
+        return $this;
+    }
+
+    /**
+     * @return int
+     */
+    public function getDecay()
+    {
+        return $this->decay;
+    }
+
+    /**
+     * @param int $decay
+     * @return $this
+     */
+    public function setDecay($decay)
+    {
+        $this->decay = $decay;
+        return $this;
+    }
+
+    /**
+     * @return int
+     */
+    public function getNumAttempts()
+    {
+        return $this->getCache()->get($this->getIdentifier(), 0);
+    }
+
+    /**
+     * @return int
+     */
+    public function getNumAttemptsRemaining()
+    {
+        return max(0, $this->getMaxAttempts() - $this->getNumAttempts());
+    }
+
+    /**
+     * @return int
+     */
+    public function getTimeToReset()
+    {
+        if ($expiry = $this->getCache()->get($this->getIdentifier() . '-timer')) {
+            return $expiry - DBDatetime::now()->getTimestamp();
+        }
+        return  0;
+    }
+
+    /**
+     * @return $this
+     */
+    public function clearAttempts()
+    {
+        $this->getCache()->delete($this->getIdentifier());
+        return $this;
+    }
+
+    /**
+     * Store a hit in the rate limit cache
+     *
+     * @return $this
+     */
+    public function hit()
+    {
+        if (!$this->getCache()->has($this->getIdentifier())) {
+            $ttl = $this->getDecay() * 60;
+            $expiry = DBDatetime::now()->getTimestamp() + $ttl;
+            $this->getCache()->set($this->getIdentifier() . '-timer', $expiry, $ttl);
+        } else {
+            $expiry = $this->getCache()->get($this->getIdentifier() . '-timer');
+            $ttl = $expiry - DBDatetime::now()->getTimestamp();
+        }
+        $this->getCache()->set($this->getIdentifier(), $this->getNumAttempts() + 1, $ttl);
+        return $this;
+    }
+
+    /**
+     * @return bool
+     */
+    public function canAccess()
+    {
+        if ($this->getNumAttempts() >= $this->getMaxAttempts()) {
+            // if the timer cache item still exists then they are locked out
+            if ($this->getCache()->has($this->getIdentifier() . '-timer')) {
+                return false;
+            }
+            // the timer key has expired so we can clear their attempts and start again
+            $this->clearAttempts();
+        }
+        return true;
+    }
+}

src/ORM/FieldType/DBDatetime.php

@@ -190,14 +190,15 @@ class DBDatetime extends DBDate implements TemplateGlobalProvider
      */
     public static function set_mock_now($datetime)
     {
-        if ($datetime instanceof DBDatetime) {
-            self::$mock_now = $datetime;
-        } elseif (is_string($datetime)) {
-            self::$mock_now = DBField::create_field('Datetime', $datetime);
-        } else {
-            throw new InvalidArgumentException('DBDatetime::set_mock_now(): Wrong format: ' . $datetime);
+        if (!$datetime instanceof DBDatetime) {
+            $value = $datetime;
+            $datetime = DBField::create_field('Datetime', $datetime);
+            if ($datetime === false) {
+                throw new InvalidArgumentException('DBDatetime::set_mock_now(): Wrong format: ' . $value);
             }
         }
+        self::$mock_now = $datetime;
+    }
 
     /**
      * Clear any mocked date, which causes

tests/php/Control/Middleware/Control/TestController.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace SilverStripe\Control\Tests\Middleware\Control;
+
+use SilverStripe\Control\Controller;
+
+class TestController extends Controller
+{
+    public function index($request)
+    {
+        return "Success";
+    }
+
+    public function Link($action = null)
+    {
+        return Controller::join_links('TestController', $action);
+    }
+}

tests/php/Control/Middleware/RateLimitMiddlewareTest.php

@@ -0,0 +1,67 @@
+<?php
+
+namespace SilverStripe\Control\Tests\Middleware;
+
+use SilverStripe\Control\Middleware\RateLimitMiddleware;
+use SilverStripe\Control\Middleware\RequestHandlerMiddlewareAdapter;
+use SilverStripe\Control\Tests\Middleware\Control\TestController;
+use SilverStripe\Core\Config\Config;
+use SilverStripe\Core\Injector\Injector;
+use SilverStripe\Dev\FunctionalTest;
+use SilverStripe\ORM\FieldType\DBDatetime;
+
+class RateLimitMiddlewareTest extends FunctionalTest
+{
+
+    protected static $extra_controllers = [
+        TestController::class,
+    ];
+
+    protected function setUp()
+    {
+        parent::setUp();
+        DBDatetime::set_mock_now('2017-09-27 00:00:00');
+        Config::modify()->set(Injector::class, 'TestRateLimitMiddleware', [
+            'class' => RateLimitMiddleware::class,
+            'properties' => [
+                'ExtraKey' => 'test',
+                'MaxAttempts' => 2,
+                'Decay' => 1,
+            ],
+        ]);
+        Config::modify()->set(Injector::class, 'RateLimitTestController', [
+            'class' => RequestHandlerMiddlewareAdapter::class,
+            'properties' => [
+                'RequestHandler' => '%$' . TestController::class,
+                'Middlewares' => [
+                    '%$TestRateLimitMiddleware'
+                ],
+            ],
+        ]);
+    }
+
+    protected function getExtraRoutes()
+    {
+        $rules = parent::getExtraRoutes();
+        $rules['TestController//$Action/$ID/$OtherID'] = '%$RateLimitTestController';
+        return $rules;
+    }
+
+    public function testRequest()
+    {
+        $response = $this->get('TestController');
+        $this->assertFalse($response->isError());
+        $this->assertEquals(2, $response->getHeader('X-RateLimit-Limit'));
+        $this->assertEquals(1, $response->getHeader('X-RateLimit-Remaining'));
+        $this->assertEquals(DBDatetime::now()->getTimestamp() + 60, $response->getHeader('X-RateLimit-Reset'));
+        $this->assertEquals('Success', $response->getBody());
+        $response = $this->get('TestController');
+        $this->assertFalse($response->isError());
+        $this->assertEquals(0, $response->getHeader('X-RateLimit-Remaining'));
+        $response = $this->get('TestController');
+        $this->assertTrue($response->isError());
+        $this->assertEquals(429, $response->getStatusCode());
+        $this->assertEquals(60, $response->getHeader('retry-after'));
+        $this->assertNotEquals('Success', $response->getBody());
+    }
+}

tests/php/Core/Cache/RateLimiterTest.php

@@ -0,0 +1,127 @@
+<?php
+
+namespace SilverStripe\Core\Tests\Cache;
+
+use Psr\SimpleCache\CacheInterface;
+use SilverStripe\Core\Cache\RateLimiter;
+use SilverStripe\Dev\SapphireTest;
+use SilverStripe\ORM\FieldType\DBDatetime;
+use Symfony\Component\Cache\Simple\ArrayCache;
+
+class RateLimiterTest extends SapphireTest
+{
+
+    protected function setUp()
+    {
+        parent::setUp();
+        DBDatetime::set_mock_now('2017-09-27 00:00:00');
+    }
+
+    public function testConstruct()
+    {
+        $cache = new ArrayCache();
+        $rateLimiter = new RateLimiter(
+            'test',
+            5,
+            1
+        );
+        $rateLimiter->setCache($cache);
+        $this->assertEquals('test', $rateLimiter->getIdentifier());
+        $this->assertEquals(5, $rateLimiter->getMaxAttempts());
+        $this->assertEquals(1, $rateLimiter->getDecay());
+    }
+
+    public function testGetNumberOfAttempts()
+    {
+        $cache = new ArrayCache();
+        $rateLimiter = new RateLimiter(
+            'test',
+            5,
+            1
+        );
+        $rateLimiter->setCache($cache);
+        for ($i = 0; $i < 7; ++$i) {
+            $this->assertEquals($i, $rateLimiter->getNumAttempts());
+            $rateLimiter->hit();
+        }
+    }
+
+    public function testGetNumAttemptsRemaining()
+    {
+        $cache = new ArrayCache();
+        $rateLimiter = new RateLimiter(
+            'test',
+            1,
+            1
+        );
+        $rateLimiter->setCache($cache);
+        $this->assertEquals(1, $rateLimiter->getNumAttemptsRemaining());
+        $rateLimiter->hit();
+        $this->assertEquals(0, $rateLimiter->getNumAttemptsRemaining());
+        $rateLimiter->hit();
+        $this->assertEquals(0, $rateLimiter->getNumAttemptsRemaining());
+    }
+
+    public function testGetTimeToReset()
+    {
+        $cache = new ArrayCache();
+        $rateLimiter = new RateLimiter(
+            'test',
+            1,
+            1
+        );
+        $rateLimiter->setCache($cache);
+        $this->assertEquals(0, $rateLimiter->getTimeToReset());
+        $rateLimiter->hit();
+        $this->assertEquals(60, $rateLimiter->getTimeToReset());
+        DBDatetime::set_mock_now(DBDatetime::now()->getTimestamp() + 30);
+        $this->assertEquals(30, $rateLimiter->getTimeToReset());
+    }
+
+    public function testClearAttempts()
+    {
+        $cache = new ArrayCache();
+        $rateLimiter = new RateLimiter(
+            'test',
+            1,
+            1
+        );
+        $rateLimiter->setCache($cache);
+        for ($i = 0; $i < 5; ++$i) {
+            $rateLimiter->hit();
+        }
+        $this->assertEquals(5, $rateLimiter->getNumAttempts());
+        $rateLimiter->clearAttempts();
+        $this->assertEquals(0, $rateLimiter->getNumAttempts());
+    }
+
+    public function testHit()
+    {
+        $cache = new ArrayCache();
+        $rateLimiter = new RateLimiter(
+            'test',
+            1,
+            1
+        );
+        $rateLimiter->setCache($cache);
+        $this->assertFalse($cache->has('test'));
+        $this->assertFalse($cache->has('test-timer'));
+        $rateLimiter->hit();
+        $this->assertTrue($cache->has('test'));
+        $this->assertTrue($cache->has('test-timer'));
+    }
+
+    public function testCanAccess()
+    {
+        $cache = new ArrayCache();
+        $rateLimiter = new RateLimiter(
+            'test',
+            1,
+            1
+        );
+        $rateLimiter->setCache($cache);
+        $this->assertTrue($rateLimiter->canAccess());
+        $rateLimiter->hit();
+        $this->assertFalse($rateLimiter->canAccess());
+    }
+}