Update

config/dev.exs

@@ -16,10 +16,14 @@ config :nulla, Nulla.Repo,
 # The watchers configuration can be used to run external
 # watchers to your application. For example, we can use it
 # to bundle .js and .css sources.
+host = System.get_env("PHX_HOST") || "example.com"
+port = String.to_integer(System.get_env("PORT") || "4000")
+
 config :nulla, NullaWeb.Endpoint,
   # Binding to loopback ipv4 address prevents access from other machines.
   # Change to `ip: {0, 0, 0, 0}` to allow access from other machines.
-  http: [ip: {127, 0, 0, 1}, port: 4000],
+  url: [host: host, port: port],
+  http: [ip: {127, 0, 0, 1}, port: port],
   check_origin: false,
   code_reloader: true,
   debug_errors: true,

lib/nulla/activitypub.ex

@@ -51,7 +51,12 @@ defmodule Nulla.ActivityPub do
       indexable: actor.indexable,
       published: DateTime.to_iso8601(actor.published),
       memorial: actor.memorial,
-      publicKey: actor.publicKey,
+      publicKey:
+        Jason.OrderedObject.new(
+          id: actor.publicKey["id"],
+          owner: actor.publicKey["owner"],
+          publicKeyPem: actor.publicKey["publicKeyPem"]
+        ),
       tag: actor.tag,
       attachment: actor.attachment,
       endpoints: actor.endpoints,

lib/nulla/keygen.ex

@@ -1,18 +1,23 @@
 defmodule Nulla.KeyGen do
   def gen do
-    rsa_key = :public_key.generate_key({:rsa, 2048, 65537})
+    key = :public_key.generate_key({:rsa, 2048, 65_537})
+    entry = :public_key.pem_entry_encode(:RSAPrivateKey, key)
 
-    {:RSAPrivateKey, :"two-prime", n, e, _d, _p, _q, _dp, _dq, _qi, _other} = rsa_key
-    public_key = {:RSAPublicKey, n, e}
+    private_pem =
+      :public_key.pem_encode([entry])
+      |> String.trim_trailing()
+      |> Kernel.<>("\n")
 
-    private_entry =
-      {:PrivateKeyInfo, :public_key.der_encode(:RSAPrivateKey, rsa_key), :not_encrypted}
+    [private_key_code] = :public_key.pem_decode(private_pem)
+    private_key = :public_key.pem_entry_decode(private_key_code)
+    {:RSAPrivateKey, _, modulus, exponent, _, _, _, _, _, _, _} = private_key
+    public_key = {:RSAPublicKey, modulus, exponent}
+    public_key = :public_key.pem_entry_encode(:SubjectPublicKeyInfo, public_key)
 
-    public_entry =
-      {:SubjectPublicKeyInfo, :public_key.der_encode(:RSAPublicKey, public_key), :not_encrypted}
-
-    private_pem = :public_key.pem_encode([private_entry])
-    public_pem = :public_key.pem_encode([public_entry])
+    public_pem =
+      :public_key.pem_encode([public_key])
+      |> String.trim_trailing()
+      |> Kernel.<>("\n")
 
     {public_pem, private_pem}
   end

lib/nulla/models/activity.ex

@@ -4,13 +4,13 @@ defmodule Nulla.Models.Activity do
   alias Nulla.Repo
   alias Nulla.Snowflake
 
+  @derive {Jason.Encoder, only: [:ap_id, :type, :actor, :object]}
   @primary_key {:id, :integer, autogenerate: false}
   schema "activities" do
     field :ap_id, :string
     field :type, :string
     field :actor, :string
-    field :object, :map
-    field :cc, {:array, :string}, default: []
+    field :object, :string
 
     timestamps()
   end
@@ -18,7 +18,7 @@ defmodule Nulla.Models.Activity do
   @doc false
   def changeset(activity, attrs) do
     activity
-    |> cast(attrs, [:ap_id, :type, :actor, :object, :to])
+    |> cast(attrs, [:ap_id, :type, :actor, :object])
     |> validate_required([:ap_id, :type, :actor, :object])
     |> validate_inclusion(:type, ~w(Create Update Delete Undo Like Announce Follow Accept Reject))
   end

lib/nulla/models/actor.ex

@@ -78,15 +78,8 @@ defmodule Nulla.Models.Actor do
       :followers,
       :inbox,
       :outbox,
-      :featured,
-      :featuredTags,
       :preferredUsername,
       :url,
-      :manuallyApprovesFollowers,
-      :discoverable,
-      :indexable,
-      :published,
-      :memorial,
       :publicKey,
       :endpoints
     ])

lib/nulla/models/relation.ex

@@ -48,7 +48,7 @@ defmodule Nulla.Models.Relation do
       :local_actor_id,
       :remote_actor_id
     ])
-    |> validate_required([:id, :local_actor_id, :remote_actor_id])
+    |> validate_required([:local_actor_id, :remote_actor_id])
     |> unique_constraint([:local_actor_id, :remote_actor_id])
   end
 
@@ -61,6 +61,10 @@ defmodule Nulla.Models.Relation do
     |> Repo.insert()
   end
 
+  def get_relation(by) when is_map(by) or is_list(by) do
+    Repo.get_by(__MODULE__, by)
+  end
+
   def count_following(local_actor_id) do
     __MODULE__
     |> where([r], r.local_actor_id == ^local_actor_id and r.following == true)

lib/nulla/utils.ex

@@ -1,4 +1,6 @@
 defmodule Nulla.Utils do
+  alias Finch
+
   def fetch_remote_actor(uri) do
     headers = [
       {"Accept", "application/activity+json"},
@@ -8,7 +10,7 @@ defmodule Nulla.Utils do
 
     request = Finch.build(:get, uri, headers)
 
-    case Finch.request(request, Finch) do
+    case Finch.request(request, Nulla.Finch) do
       {:ok, %Finch.Response{status: 200, body: body}} ->
         case Jason.decode(body) do
           {:ok, data} -> {:ok, data}

lib/nulla_web/controllers/actor_controller.ex

@@ -17,7 +17,7 @@ defmodule NullaWeb.ActorController do
         |> json(%{error: "Not Found"})
 
       %Actor{} = actor ->
-        if accept in ["application/activity+json", "application/ld+json"] do
+        if accept =~ "json" do
           conn
           |> put_resp_content_type("application/activity+json")
           |> send_resp(200, Jason.encode!(ActivityPub.actor(actor)))

lib/nulla_web/controllers/follow_controller.ex

@@ -18,7 +18,7 @@ defmodule NullaWeb.FollowController do
         _ -> 1
       end
 
-    following_list = Relation.get_following(actor.id, page, limit)
+    following_list = Enum.map(Relation.get_following(actor.id, page, limit), & &1.ap_id)
 
     conn
     |> put_resp_content_type("application/activity+json")
@@ -49,7 +49,7 @@ defmodule NullaWeb.FollowController do
         _ -> 1
       end
 
-    followers_list = Relation.get_followers(actor.id, page, limit)
+    followers_list = Enum.map(Relation.get_followers(actor.id, page, limit), & &1.ap_id)
 
     conn
     |> put_resp_content_type("application/activity+json")

lib/nulla_web/controllers/inbox_controller.ex

@@ -1,51 +1,97 @@
 defmodule NullaWeb.InboxController do
   use NullaWeb, :controller
-  alias Nulla.HTTPSignature
   alias Nulla.ActivityPub
   alias Nulla.Snowflake
+  alias Nulla.HTTPSignature
   alias Nulla.Utils
   alias Nulla.Models.User
   alias Nulla.Models.Actor
   alias Nulla.Models.Relation
   alias Nulla.Models.Activity
 
-  def inbox(
-        conn,
-        %{"id" => follow_id, "type" => "Follow", "actor" => actor_uri, "object" => target_uri}
-      ) do
+  def inbox(conn, %{
+        "id" => follow_id,
+        "type" => "Follow",
+        "actor" => actor_uri,
+        "object" => target_uri
+      }) do
     accept_id = Snowflake.next_id()
 
     with local_actor <- Actor.get_actor(ap_id: target_uri),
          {:ok, remote_actor_json} <- Utils.fetch_remote_actor(actor_uri),
          :ok <- HTTPSignature.verify(conn, remote_actor_json),
-         remote_actor <-
-           Actor.create_actor(
+         {:ok, remote_actor} <- get_or_create_actor(remote_actor_json),
+         {:ok, follow_activity} <-
+           create_follow_activity(follow_id, remote_actor.ap_id, target_uri),
+         {:ok, accept_activity} <-
+           create_accept_activity(accept_id, local_actor, follow_activity),
+         {:ok, _relation} <- get_or_create_relation(local_actor.id, remote_actor.id),
+         :ok <- deliver_accept(accept_activity, remote_actor_json, local_actor) do
+      send_resp(conn, 200, "")
+    else
+      error ->
+        IO.inspect(error, label: "Follow error")
+        json(conn, %{"error" => "Failed to process Follow"})
+    end
+  end
+
+  defp get_or_create_actor(remote_actor_json) do
+    ap_id = remote_actor_json["id"]
+
+    case Actor.get_actor(ap_id: ap_id) do
+      nil ->
+        params =
           remote_actor_json
-             |> Map.put("ap_id", remote_actor_json["id"])
+          |> Map.put("ap_id", ap_id)
           |> Map.delete("id")
-             |> Map.put("domain", URI.parse(remote_actor_json["id"]).host)
-           ),
-         follow_activity <-
+          |> Map.put("domain", URI.parse(ap_id).host)
+
+        case Actor.create_actor(params) do
+          {:ok, actor} -> {:ok, actor}
+          {:error, changeset} -> {:error, {:actor_creation_failed, changeset}}
+        end
+
+      actor ->
+        {:ok, actor}
+    end
+  end
+
+  defp create_follow_activity(follow_id, actor_id, target_uri) do
     Activity.create_activity(%{
       ap_id: follow_id,
       type: "Follow",
-             actor: remote_actor.id,
+      actor: actor_id,
       object: target_uri
-           }),
-         accept_activity <-
+    })
+  end
+
+  defp create_accept_activity(accept_id, local_actor, follow_activity) do
     Activity.create_activity(%{
       id: accept_id,
       ap_id: "https://#{local_actor.domain}/activities/accept/#{accept_id}",
       type: "Accept",
       actor: local_actor.ap_id,
-             object: follow_activity
-           }),
-         _ <-
+      object: Jason.encode!(follow_activity)
+    })
+  end
+
+  defp get_or_create_relation(local_actor_id, remote_actor_id) do
+    case Relation.get_relation(local_actor_id: local_actor_id, remote_actor_id: remote_actor_id) do
+      nil ->
         Relation.create_relation(%{
           followed_by: true,
-             local_actor_id: local_actor.id,
-             remote_actor_id: remote_actor.id
-           }) do
+          local_actor_id: local_actor_id,
+          remote_actor_id: remote_actor_id
+        })
+
+      relation ->
+        {:ok, relation}
+    end
+  end
+
+  defp deliver_accept(accept_activity, remote_actor_json, local_actor) do
+    inbox_url = remote_actor_json["inbox"]
+    accept_activity = %Activity{accept_activity | object: Jason.decode!(accept_activity.object)}
     body = Jason.encode!(ActivityPub.activity(accept_activity))
 
     digest =
@@ -57,24 +103,26 @@ defmodule NullaWeb.InboxController do
       DateTime.utc_now()
       |> Calendar.strftime("%a, %d %b %Y %H:%M:%S GMT")
 
-      host = URI.parse(actor_uri).host
-      request_target = "post /inbox"
+    uri = URI.parse(inbox_url)
+    request_target = "post #{uri.path}"
 
-      signature_string =
-        """
+    signature_string = """
     (request-target): #{request_target}
-        host: #{host}
+    host: #{uri.host}
     date: #{date}
     digest: #{digest}
     """
 
     user = User.get_user(id: local_actor.id)
-      privateKeyPem = user.privateKey["privateKeyPem"]
 
     private_key =
-        :public_key.pem_decode(privateKeyPem)
-        |> hd()
-        |> :public_key.pem_entry_decode()
+      case :public_key.pem_decode(user.privateKeyPem) do
+        [{_type, der, _rest}] ->
+          :public_key.der_decode(:RSAPrivateKey, der)
+
+        _ ->
+          raise "Invalid PEM format"
+      end
 
     signature =
       :public_key.sign(signature_string, :sha256, private_key)
@@ -90,17 +138,28 @@ defmodule NullaWeb.InboxController do
       |> String.replace("\n", "")
       |> String.trim()
 
-      conn
-      |> put_resp_content_type("application/activity+json")
-      |> put_resp_header("host", host)
-      |> put_resp_header("date", date)
-      |> put_resp_header("signature", signature_header)
-      |> put_resp_header("digest", digest)
-      |> send_resp(200, body)
-    else
-      error ->
-        IO.inspect(error, label: "Follow error")
-        json(conn, %{"error" => "Failed to process Follow"})
+    headers = [
+      {"host", uri.host},
+      {"date", date},
+      {"digest", digest},
+      {"signature", signature_header},
+      {"content-type", "application/activity+json"}
+    ]
+
+    request = Finch.build(:post, inbox_url, headers, body)
+
+    case Finch.request(request, Nulla.Finch) do
+      {:ok, %Finch.Response{status: code}} when code in 200..299 ->
+        IO.puts("Accept delivered successfully")
+        :ok
+
+      {:ok, %Finch.Response{status: code, body: resp}} ->
+        IO.inspect({:error, code, resp}, label: "Failed to deliver Accept")
+        {:error, {:http_error, code}}
+
+      {:error, reason} ->
+        IO.inspect(reason, label: "Finch delivery failed")
+        {:error, reason}
     end
   end
 end

lib/nulla_web/router.ex

@@ -2,12 +2,12 @@ defmodule NullaWeb.Router do
   use NullaWeb, :router
 
   pipeline :browser do
-    plug :accepts, ["html", "activity+json", "ld+json"]
+    plug :accepts, ["html", "json", "activity+json", "ld+json"]
     plug :fetch_session
     plug :fetch_live_flash
     plug :put_root_layout, html: {NullaWeb.Layouts, :root}
-    plug :protect_from_forgery
-    plug :put_secure_browser_headers
+    # plug :protect_from_forgery
+    # plug :put_secure_browser_headers
   end
 
   pipeline :api do

priv/repo/migrations/20250615130714_create_actors.exs

@@ -15,7 +15,7 @@ defmodule Nulla.Repo.Migrations.CreateActors do
       add :featuredTags, :string
       add :preferredUsername, :string, null: false
       add :name, :string
-      add :summary, :string
+      add :summary, :text
       add :url, :string
       add :manuallyApprovesFollowers, :boolean
       add :discoverable, :boolean, default: true

priv/repo/migrations/20250615131856_create_activities.exs

@@ -6,14 +6,14 @@ defmodule Nulla.Repo.Migrations.CreateActivities do
       add :id, :bigint, primary_key: true
       add :ap_id, :string, null: false
       add :type, :string, null: false
-      add :actor_id, references(:actors, type: :bigint, on_delete: :nothing), null: false
-      add :object, :map, null: false
-      add :to, {:array, :string}, default: []
+      add :actor, :string, null: false
+      add :object, :text, null: false
 
       timestamps()
     end
 
+    create index(:activities, [:ap_id])
     create index(:activities, [:type])
-    create index(:activities, [:actor_id])
+    create index(:activities, [:actor])
   end
 end