added proper application-signing

- we now check whether the request was sent from contentnation and approve the request with contentnations pub key
- fix issue where inbox wasn't gotten as it also got a username
- rough initial draft of parsing of connector-specific data (plugins/federator/contentnation::jsonToActivity)
- added key paths and headername to config

config.ini

@@ -13,10 +13,15 @@ compiledir = '../cache'
 
 [plugins]
 rediscache = 'rediscache.php'
-dummy = 'dummyconnector.php'
+# dummy = 'dummyconnector.php'
 contentnation = 'contentnation.php'
-mastodon = 'mastodon.php'
 
 [maintenance]
 username = 'federatoradmin'
 password = '*change*me*as*well'
+
+[keys]
+headerSenderName = 'contentnation'
+contentnationPublicKeyPath = '../contentnation.pub'
+federatorPrivateKeyPath = '../federator.key'
+federatorPublicKeyPath = '../federator.pub'

contentnation.pub

@@ -0,0 +1,14 @@
+-----BEGIN PUBLIC KEY-----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+-----END PUBLIC KEY-----

federator.pub

@@ -0,0 +1,14 @@
+-----BEGIN PUBLIC KEY-----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+-----END PUBLIC KEY-----

php/federator/api.php

@@ -195,12 +195,11 @@ class Api extends Main
     /**
      * check if the headers include a valid signature
      *
-     * @param string[] $headers
+     * @param string[] $headers the headers
-     *          permission(s) to check for
      * @throws Exceptions\PermissionDenied
      * @return string|Exceptions\PermissionDenied
      */
-    public static function checkSignature($headers)
+    public function checkSignature($headers)
     {
         $signatureHeader = $headers['Signature'] ?? null;
 
@@ -209,13 +208,19 @@ class Api extends Main
             throw new Exceptions\PermissionDenied("Missing Signature header");
         }
 
+        $config = $this->getConfig();
+
         // Parse Signature header
         preg_match_all('/(\w+)=["\']?([^"\',]+)["\']?/', $signatureHeader, $matches);
         $signatureParts = array_combine($matches[1], $matches[2]);
 
         $signature = base64_decode($signatureParts['signature']);
-        $keyId = $signatureParts['keyId'];
         $signedHeaders = explode(' ', $signatureParts['headers']);
+        if (isset($headers['X-Sender']) && $headers['X-Sender'] === $config['keys']['headerSenderName']) {
+            $pKeyPath = $_SERVER['DOCUMENT_ROOT'] . $config['keys']['contentnationPublicKeyPath'];
+            $publicKeyPem = file_get_contents($pKeyPath);
+        } else {
+            $keyId = $signatureParts['keyId'];
 
             // Fetch public key from `keyId` (usually actor URL + #main-key)
             [$publicKeyData, $info] = \Federator\Main::getFromRemote($keyId, ['Accept: application/activity+json']);
@@ -232,10 +237,11 @@ class Api extends Main
             }
 
             $publicKeyPem = $actor['publicKey']['publicKeyPem'] ?? null;
+        }
 
-        if (!isset($publicKeyPem)) {
+        if (!isset($publicKeyPem) || $publicKeyPem === false) {
             http_response_code(500);
-            throw new Exceptions\PermissionDenied("Invalid public key format from actor with keyId: $keyId");
+            throw new Exceptions\PermissionDenied("Public key couldn't be determined");
         }
 
         // Reconstruct the signed string
@@ -251,6 +257,7 @@ class Api extends Main
 
             $signedString .= strtolower($header) . ": " . $headerValue . "\n";
         }
+
         $signedString = rtrim($signedString);
 
         // Verify the signature
@@ -261,12 +268,11 @@ class Api extends Main
         }
         if ($verified != 1) {
             http_response_code(500);
-            throw new Exceptions\PermissionDenied("Signature verification failed for publicKey with keyId: $keyId");
+            throw new Exceptions\PermissionDenied("Signature verification failed for publicKey");
         }
 
-        $actorId = $actor['id'];
         // Signature is valid!
-        return "Signature verified from actor: " . $actorId;
+        return "Signature verified.";
     }
 
     /**

php/federator/api/fedusers.php

@@ -69,6 +69,7 @@ class FedUsers implements APIInterface
                 } else {
                     switch ($paths[1]) {
                         case 'inbox':
+                            $_username = NULL;
                             $handler = new FedUsers\Inbox($this->main);
                             break;
                         default:

php/federator/api/fedusers/outbox.php

@@ -106,14 +106,18 @@ class Outbox implements \Federator\Api\FedUsers\FedUsersInterface
             return false;
         }
 
-        $activity = is_string($_rawInput) ? json_decode($_rawInput, true) : null;
+        $input = is_string($_rawInput) ? json_decode($_rawInput, true) : null;
         $host = $_SERVER['SERVER_NAME'];
-
+        if (!is_array($input)) {
-        if (!is_array($activity)) {
             error_log("Outbox::post Input wasn't of type array");
             return false;
         }
-        $outboxActivity = \Federator\Data\ActivityPub\Factory::newActivityFromJson($activity);
+
+        if (isset($allHeaders['X-Sender']) && $allHeaders['X-Sender'] === $this->main->getConfig()['keys']['headerSenderName']) {
+            $outboxActivity = $this->main->getConnector()->jsonToActivity($input);
+        } else {
+            $outboxActivity = \Federator\Data\ActivityPub\Factory::newActivityFromJson($input);
+        }
 
         if ($outboxActivity === false) {
             error_log("Outbox::post couldn't create outboxActivity");
@@ -142,9 +146,20 @@ class Outbox implements \Federator\Api\FedUsers\FedUsersInterface
                 }
             }
         }
+
+        if (empty($users)) { // todo remove, debugging for now
+            $rootDir = $_SERVER['DOCUMENT_ROOT'] . '../';
+            // Save the raw input and parsed JSON to a file for inspection
+            file_put_contents(
+                $rootDir . 'logs/outbox.log',
+                date('Y-m-d H:i:s') . ": ==== POST Outbox Activity ====\n" . json_encode($outboxActivity, JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT) . "\n\n",
+                FILE_APPEND
+            );
+        }
         if ($_user !== false && !in_array($_user, $users, true)) {
             $users[] = $_user;
         }
+
         foreach ($users as $user) {
             if (!isset($user)) {
                 continue;
@@ -152,6 +167,7 @@ class Outbox implements \Federator\Api\FedUsers\FedUsersInterface
 
             $this->postForUser($user, $outboxActivity);
         }
+
         return json_encode($outboxActivity, JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT);
     }
 

php/federator/connector/connector.php

@@ -56,4 +56,12 @@ interface Connector
      * @return \Federator\Data\Stats|false
      */
     public function getRemoteStats();
+
+    /**
+     * Convert jsonData to Activity format
+     *
+     * @param array<string, mixed> $jsonData the json data from our platfrom
+     * @return \Federator\Data\ActivityPub\Common\Activity|false
+     */
+    public function jsonToActivity(array $jsonData);
 }

plugins/federator/contentnation.php

@@ -329,6 +329,39 @@ class ContentNation implements Connector
         }
         return $user;
     }
+
+    /**
+     * Convert jsonData to Activity format
+     *
+     * @param array<string, mixed> $jsonData the json data from our platfrom
+     * @return \Federator\Data\ActivityPub\Common\Activity|false
+     */
+    public function jsonToActivity(array $jsonData)
+    {
+        $ap = [
+            '@context' => 'https://www.w3.org/ns/activitystreams',
+            'type' => 'Create',
+            'id' => $jsonData['id'] ?? null,
+            'actor' => $jsonData['actor']['id'] ?? null,
+            'published' => $jsonData['object']['published'] ?? null,
+            'to' => ['https://www.w3.org/ns/activitystreams#Public'],
+            'cc' => [$jsonData['related']['cc']['followers'] ?? null],
+            'object' => [
+                'type' => 'Note',
+                'id' => $jsonData['object']['id'] ?? null,
+                'summary' => $jsonData['object']['summary'] ?? '',
+                'content' => $jsonData['object']['content'] ?? '',
+                'published' => $jsonData['object']['published'] ?? null,
+                'attributedTo' => $jsonData['actor']['id'] ?? null,
+                'to' => ['https://www.w3.org/ns/activitystreams#Public'],
+                'cc' => [$jsonData['related']['cc']['followers'] ?? null],
+                'url' => $jsonData['object']['url'] ?? null,
+                'inReplyTo' => $jsonData['related']['article']['id'] ?? null,
+            ],
+        ];
+
+        return \Federator\Data\ActivityPub\Factory::newActivityFromJson($ap);
+    }
 }
 
 namespace Federator;

plugins/federator/dummyconnector.php

@@ -57,6 +57,16 @@ class DummyConnector implements Connector
         return $stats;
     }
 
+    /**
+     * Convert jsonData to Activity format
+     *
+     * @param array<string, mixed> $jsonData the json data from our platfrom @unused-param
+     * @return \Federator\Data\ActivityPub\Common\Activity|false
+     */
+    public function jsonToActivity(array $jsonData) {
+        return false;
+    }
+
     /**
      * get remote user by name
      * @param string $_name user or profile name

plugins/federator/rediscache.php

@@ -90,6 +90,17 @@ class RedisCache implements Cache
         return false;
     }
 
+    /**
+     * Convert jsonData to Activity format
+     *
+     * @param array<string, mixed> $jsonData the json data from our platfrom @unused-param
+     * @return \Federator\Data\ActivityPub\Common\Activity|false
+     */
+    public function jsonToActivity(array $jsonData) {
+        error_log("rediscache::jsonToActivity not implemented");
+        return false;
+    }
+
     /**
      * get posts by given user
      *