added support for activitypub follows

app/Http/Controllers/AP/APInboxController.php

@@ -4,6 +4,10 @@ namespace App\Http\Controllers\AP;
 
 use App\Models\User;
 use App\Models\Actor;
+use App\Models\Activity;
+
+use App\Types\TypeActor;
+use App\Types\TypeActivity;
 
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Log;
@@ -13,7 +17,86 @@ class APInboxController extends Controller
 {
     public function inbox (User $user)
     {
+        $request = request ();
+        $type = $request->get ("type");
+
+        switch ($type) {
+            case "Follow":
+                $this->handle_follow ($user, $request->all ());
+                break;
+
+            case "Undo":
+                $this->handle_undo ($user, $request->all ());
+                break;
+        }
+
         Log::info ("APInboxController@index");
-        Log::info (json_encode (request ()->all ()));
+        Log::info (json_encode ($request->all ()));
+    }
+
+    private function handle_follow (User $user, $activity)
+    {
+        if (TypeActivity::activity_exists ($activity ["id"]))
+            return response ()->json (["error" => "Activity already exists",], 409);
+
+        $actor = TypeActor::actor_exists_or_obtain ($activity ["actor"]);
+
+        $target = TypeActor::actor_get_local ($activity ["object"]);
+        if (!$target || !$target->user)
+            return response ()->json (["error" => "Target not found",], 404);
+
+        $activity ["activity_id"] = $activity ["id"];
+
+        // there's no follows model, it'll be handled with the activity model
+        $act = Activity::create ($activity);
+
+        // TODO: Users should be able to manually check this
+        $accept_activity = TypeActivity::craft_accept ($act);
+        $response = TypeActivity::post_activity ($accept_activity, $target, $actor);
+        if (!$response)
+        {
+            return response ()->json ([
+                "error" => "Error posting activity",
+            ], 500);
+        }
+
+        $target->user->friends += 1;
+        $target->user->save ();
+    }
+
+    public function handle_undo (User $user, $activity)
+    {
+        if (TypeActivity::activity_exists ($activity ["id"]))
+            return response ()->json (["error" => "Activity already exists",], 409);
+
+        $actor = TypeActor::actor_exists_or_obtain ($activity ["actor"]);
+
+        $child_activity = $activity ["object"];
+        if (!TypeActivity::activity_exists ($child_activity ["id"]))
+            return response ()->json (["error" => "Child activity not found",], 404);
+
+        $child_activity = Activity::where ("activity_id", $child_activity ["id"])->first ();
+        switch ($child_activity->type)
+        {
+            case "Follow":
+                // TODO: Move this to its own function
+                // TODO: Should the accept activity be deleted?
+                $followed_user = TypeActor::actor_get_local ($child_activity ["object"]);
+                if (!$followed_user || !$followed_user->user)
+                    return response ()->json (["error" => "Target not found",], 404);
+
+                $followed_user->user->friends -= 1;
+                $followed_user->user->save ();
+
+                $child_activity->delete ();
+                break;
+
+            default:
+                Log::info ("Unknown activity type to Undo: " . $child_activity ["type"]);
+                break;
+        }
+
+        // TODO: Should Undo create a new activity model?
+        return response ()->json (["error" => "Not implemented",], 501);
     }
 }

app/Models/Activity.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+
+class Activity extends Model
+{
+    protected $fillable = [
+        "activity_id",
+        "actor",
+        "type",
+        "object",
+        "target",
+        "summary"
+    ];
+
+    protected $casts = [
+        "object" => "array",
+        "target" => "array"
+    ];
+
+    public function actor ()
+    {
+        return $this->belongsTo (Actor::class);
+    }
+}

app/Models/Actor.php

@@ -3,6 +3,7 @@
 namespace App\Models;
 
 use App\Models\User;
+use App\Types\TypeActor;
 
 use Illuminate\Database\Eloquent\Model;
 
@@ -28,6 +29,9 @@ class Actor extends Model
         "name",
         "summary",
 
+        "icon",
+        "image",
+
         "public_key",
         "private_key"
     ];
@@ -39,86 +43,12 @@ class Actor extends Model
 
     public function create_from_user (User $user)
     {
-        $app_url = env ("APP_URL");
+        $data = TypeActor::create_from_user ($user);
-
+        return $this->create ($data);
-        $config = [
-            "private_key_bits" => 4096,
-            "private_key_type" => OPENSSL_KEYTYPE_RSA
-        ];
-
-        $res = openssl_pkey_new ($config);
-        openssl_pkey_export ($res, $private_key);
-
-        $public_key = openssl_pkey_get_details ($res);
-
-        return $this->create ([
-            "user_id" => $user->id,
-
-            "type" => "Person",
-            "actor_id" => $app_url . "/ap/v1/user/" . $user->name,
-
-            "following" => $app_url . "/ap/v1/user/" . $user->name . "/following",
-            "followers" => $app_url . "/ap/v1/user/" . $user->name . "/followers",
-
-            "liked" => $app_url . "/ap/v1/user/" . $user->name . "/liked",
-
-            "inbox" => $app_url . "/ap/v1/user/" . $user->name . "/inbox",
-            "outbox" => $app_url . "/ap/v1/user/" . $user->name . "/outbox",
-
-            "sharedInbox" => $app_url . "/ap/v1/inbox",
-
-            "preferredUsername" => $user->name,
-            "name" => $user->name,
-            "summary" => "",
-
-            "public_key" => $public_key["key"],
-            "private_key" => $private_key
-        ]);
     }
 
     public static function build_response (Actor $actor)
     {
-        $response = [
+        return TypeActor::build_response ($actor);
-            "@context" => [
-                "https://www.w3.org/ns/activitystreams",
-                "https://w3id.org/security/v1"
-            ],
-            "id" => $actor->actor_id,
-            "type" => $actor->type,
-
-            "following" => $actor->following,
-            "followers" => $actor->followers,
-
-            "liked" => $actor->liked,
-
-            "inbox" => $actor->inbox,
-            "outbox" => $actor->outbox,
-
-            "sharedInbox" => $actor->sharedInbox,
-
-            "preferredUsername" => $actor->preferredUsername,
-            "name" => $actor->name,
-            "summary" => $actor->summary,
-
-            "icon" => [
-                "type" => "Image",
-                "mediaType" => "image/jpeg",
-                "url" => $actor->icon
-            ],
-
-            "image" => [
-                "type" => "Image",
-                "mediaType" => "image/jpeg",
-                "url" => $actor->icon
-            ],
-
-            "publicKey" => [
-                "id" => $actor->actor_id . "#main-key",
-                "owner" => $actor->actor_id,
-                "publicKeyPem" => $actor->public_key
-            ]
-        ];
-
-        return $response;
     }
 }

app/Types/TypeActivity.php

@@ -0,0 +1,114 @@
+<?php
+
+namespace App\Types;
+
+use App\Models\Actor;
+use App\Models\Activity;
+
+use GuzzleHttp\Client;
+
+use Illuminate\Support\Facades\Log;
+
+class TypeActivity {
+    public static function craft_response (Activity $activity)
+    {
+        $crafted_activity = [
+            "@context" => "https://www.w3.org/ns/activitystreams",
+            "id" => $activity->activity_id,
+            "type" => $activity->type,
+            "actor" => $activity->actor,
+            "object" => $activity->object,
+        ];
+
+        if ($activity->target)
+        {
+            $crafted_activity["target"] = $activity->target;
+        }
+
+        if ($activity->summary)
+        {
+            $crafted_activity["summary"] = $activity->summary;
+        }
+
+        return $crafted_activity;
+    }
+
+    public static function craft_accept (Activity $activity)
+    {
+        $accept_activity = new Activity ();
+        $accept_activity->activity_id = env ("APP_URL") . "/activity/" . uniqid ();
+        $accept_activity->type = "Accept";
+        $accept_activity->actor = $activity->object;
+        $accept_activity->object = TypeActivity::craft_response ($activity);
+        $accept_activity->save ();
+
+        return $accept_activity;
+    }
+
+    public static function craft_signed_headers ($activity, Actor $source, Actor $target)
+    {
+        if (!$source->user)
+        {
+            Log::error ("Source not found");
+            return null;
+        }
+
+        $key_id = $source->actor_id . "#main-key";
+
+        $signer = openssl_get_privatekey ($source->private_key);
+
+        $date = gmdate ("D, d M Y H:i:s \G\M\T");
+
+        // we suppose that the activity is already json encoded
+        $hash = hash ("sha256", $activity, true);
+        $digest = base64_encode ($hash);
+
+        $url = parse_url ($target->inbox);
+        $string_to_sign = "(request-target): post ". $url["path"] . "\nhost: " . $url["host"] . "\ndate: " . $date . "\ndigest: SHA-256=" . $digest;
+
+        openssl_sign ($string_to_sign, $signature, $signer, OPENSSL_ALGO_SHA256);
+        $signature_b64 = base64_encode ($signature);
+
+        $signature_header = 'keyId="' . $key_id . '",algorithm="rsa-sha256",headers="(request-target) host date digest",signature="' . $signature_b64 . '"';
+
+        return [
+            "Host" => $url["host"],
+            "Date" => $date,
+            "Digest" => "SHA-256=" . $digest,
+            "Signature" => $signature_header,
+            "Content-Type" => "application/activity+json",
+            "Accept" => "application/activity+json",
+        ];
+    }
+
+    public static function post_activity (Activity $activity, Actor $source, Actor $target)
+    {
+        $crafted_activity = TypeActivity::craft_response ($activity);
+        $activity_json = json_encode ($crafted_activity, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_PRESERVE_ZERO_FRACTION);
+        $activity_json = mb_convert_encoding ($activity_json, "UTF-8");
+
+        $headers = TypeActivity::craft_signed_headers ($activity_json, $source, $target);
+
+        try {
+            $client = new Client ();
+            $response = $client->post ($target->inbox, [
+                "headers" => $headers,
+                "body" => $activity_json,
+                "debug" => true
+            ]);
+        }
+        catch (RequestException $e)
+        {
+            Log::error ($e->getMessage ());
+            return null;
+        }
+
+        return $response;
+    }
+
+    // some little functions
+    public static function activity_exists ($activity_id)
+    {
+        return Activity::where ("activity_id", $activity_id)->first ();
+    }
+}

app/Types/TypeActor.php

@@ -0,0 +1,200 @@
+<?php
+
+namespace App\Types;
+
+use App\Models\User;
+use App\Models\Actor;
+
+use GuzzleHttp\Client;
+use Illuminate\Support\Facades\Log;
+
+class TypeActor {
+    public static function gen_keys ()
+    {
+        $config = [
+            "private_key_bits" => 4096,
+            "private_key_type" => OPENSSL_KEYTYPE_RSA
+        ];
+
+        $res = openssl_pkey_new ($config);
+        openssl_pkey_export ($res, $private_key);
+
+        $public_key = openssl_pkey_get_details ($res);
+
+        return [
+            "public_key" => $public_key,
+            "private_key" => $private_key
+        ];
+    }
+
+    public static function create_from_user (User $user)
+    {
+        $keys = TypeActor::gen_keys ();
+        $app_url = env ("APP_URL");
+
+        return [
+            "user_id" => $user->id,
+
+            "type" => "Person",
+            "actor_id" => $app_url . "/ap/v1/user/" . $user->name,
+
+            "following" => $app_url . "/ap/v1/user/" . $user->name . "/following",
+            "followers" => $app_url . "/ap/v1/user/" . $user->name . "/followers",
+
+            "liked" => $app_url . "/ap/v1/user/" . $user->name . "/liked",
+
+            "inbox" => $app_url . "/ap/v1/user/" . $user->name . "/inbox",
+            "outbox" => $app_url . "/ap/v1/user/" . $user->name . "/outbox",
+
+            "sharedInbox" => $app_url . "/ap/v1/inbox",
+
+            "preferredUsername" => $user->name,
+            "name" => $user->name,
+            "summary" => "",
+
+            "public_key" => $keys["public_key"]["key"],
+            "private_key" => $keys["private_key"]
+        ];
+    }
+
+    public static function build_response (Actor $actor)
+    {
+        $response = [
+            "@context" => [
+                "https://www.w3.org/ns/activitystreams",
+                "https://w3id.org/security/v1"
+            ],
+            "id" => $actor->actor_id,
+            "type" => $actor->type,
+
+            "following" => $actor->following,
+            "followers" => $actor->followers,
+
+            "liked" => $actor->liked,
+
+            "inbox" => $actor->inbox,
+            "outbox" => $actor->outbox,
+
+            "endpoints" => [
+                "sharedInbox" => $actor->sharedInbox,
+            ],
+
+            "preferredUsername" => $actor->preferredUsername,
+            "name" => $actor->name,
+            "summary" => $actor->summary,
+
+            "icon" => [
+                "type" => "Image",
+                "mediaType" => "image/png",
+                "url" => $actor->icon
+            ],
+
+            "image" => [
+                "type" => "Image",
+                "mediaType" => "image/png",
+                "url" => $actor->image
+            ],
+
+            "publicKey" => [
+                "id" => $actor->actor_id . "#main-key",
+                "owner" => $actor->actor_id,
+                "publicKeyPem" => $actor->public_key
+            ]
+        ];
+
+        return $response;
+    }
+
+    public static function create_from_request ($request)
+    {
+        $actor = new Actor ();
+
+        // Use null coalescing operator `??` for safety
+        $actor->actor_id = $request['id'] ?? '';
+        $actor->type = $request['type'] ?? '';
+
+        $actor->following = $request['following'] ?? '';
+        $actor->followers = $request['followers'] ?? '';
+
+        $actor->liked = $request['liked'] ?? '';
+
+        $actor->inbox = $request['inbox'] ?? '';
+        $actor->outbox = $request['outbox'] ?? '';
+
+        $actor->sharedInbox = $request['endpoints']['sharedInbox'] ?? '';
+
+        $actor->preferredUsername = $request['preferredUsername'] ?? '';
+        $actor->name = $request['name'] ?? '';
+        $actor->summary = $request['summary'] ?? '';
+
+        // Handle nested keys with checks
+        $actor->icon = $request['icon']['url'] ?? '';
+        $actor->image = $request['image']['url'] ?? '';
+
+        // Handle nested keys in `publicKey`
+        $actor->public_key = $request['publicKey']['publicKeyPem'] ?? '';
+
+        $actor->save ();
+
+        return $actor;
+    }
+
+    public static function obtain_actor_info ($actor_id)
+    {
+        $client = new Client ();
+
+        $parsed_url = parse_url ($actor_id);
+        $url_instance = $parsed_url["scheme"] . "://" . $parsed_url["host"];
+        $url_path = explode ("/", $parsed_url["path"]);
+        $actor_name = end ($url_path);
+
+        $well_known_url = $url_instance . "/.well-known/webfinger?resource=acct:" . $actor_name . "@" . $parsed_url["host"];
+        $res = $client->get ($well_known_url);
+
+        $response = json_decode ($res->getBody ()->getContents ());
+
+        foreach ($response->links as $link)
+        {
+            if ($link->rel == "self")
+            {
+                $res = $client->request ("GET", $link->href, [
+                    "headers" => [
+                        "Accept" => "application/activity+json"
+                    ]
+                ]);
+                $actor = json_decode ($res->getBody ()->getContents (), true);
+
+                $result = TypeActor::create_from_request ($actor);
+                return $result;
+            }
+        }
+
+        return null;
+    }
+
+    // some little functions
+    public static function actor_exists ($actor_id)
+    {
+        $actor = Actor::where ("actor_id", $actor_id)->first ();
+        return $actor;
+    }
+
+    public static function actor_exists_or_obtain ($actor_id)
+    {
+        $actor = TypeActor::actor_exists ($actor_id);
+        if (!$actor)
+        {
+            $actor = TypeActor::obtain_actor_info ($actor_id);
+        }
+
+        return $actor;
+    }
+
+    public static function actor_get_local ($actor_id)
+    {
+        $actor = Actor::where ("actor_id", $actor_id)->first ();
+        if (!$actor->user)
+            return null;
+        return $actor;
+    }
+}

composer.json

@@ -7,6 +7,7 @@
     "license": "MIT",
     "require": {
         "php": "^8.2",
+        "guzzlehttp/guzzle": "^7.9",
         "intervention/image": "^3.10",
         "laravel/framework": "^11.31",
         "laravel/tinker": "^2.9"

composer.lock

@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "64b78dd438697d218ce81a8ea6afcbb3",
+    "content-hash": "067a260457c754c554a61fce0e741b0f",
     "packages": [
         {
             "name": "brick/math",

database/migrations/2024_12_27_002726_create_actors_table.php

@@ -37,6 +37,7 @@ return new class extends Migration
             $table->string ("private_key")->nullable ();
 
             $table->string ("icon")->nullable ();
+            $table->string ("image")->nullable ();
 
             $table->timestamps();
         });

database/migrations/2024_12_28_014335_create_activities_table.php

@@ -0,0 +1,35 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('activities', function (Blueprint $table) {
+            $table->id();
+
+            $table->string ("activity_id")->unique ();
+            $table->string ("actor");
+            $table->string ("type");
+            $table->json ("object");
+            $table->json ("target")->nullable ();
+            $table->text ("summary")->nullable ();
+
+            $table->timestamps();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('activities');
+    }
+};