feat: Add basic actor and webfinger setup

lib/postland.ex

@@ -13,11 +13,30 @@ defmodule Postland do
     :crypto.strong_rand_bytes(12) |> Base.encode64()
   end
 
+  def generate_keys(bits \\ 4096) do
+    {:RSAPrivateKey, _, modulus, publicExponent, _, _, _, _exponent1, _, _, _otherPrimeInfos} =
+      rsa_private_key = :public_key.generate_key({:rsa, bits, 65537})
+
+    rsa_public_key = {:RSAPublicKey, modulus, publicExponent}
+
+    pem_entry = :public_key.pem_entry_encode(:RSAPrivateKey, rsa_private_key)
+    private_key = :public_key.pem_encode([pem_entry])
+
+    pem_entry = :public_key.pem_entry_encode(:SubjectPublicKeyInfo, rsa_public_key)
+    public_key = :public_key.pem_encode([pem_entry])
+
+    %{public: public_key, private: private_key}
+  end
+
   def on_boot_setup() do
     if !setup?() do
+      %{public: public_key, private: private_key} = generate_keys()
+
       attrs = %{
         username: "welcome",
-        password: temporary_password()
+        password: temporary_password(),
+        private_key: private_key,
+        public_key: public_key
       }
 
       {:ok, _user} = Accounts.register_user(attrs)

lib/postland/accounts/user.ex

@@ -8,6 +8,8 @@ defmodule Postland.Accounts.User do
     field :hashed_password, :string, redact: true
     field :current_password, :string, virtual: true, redact: true
     field :confirmed_at, :utc_datetime
+    field :private_key, :string
+    field :public_key, :string
 
     timestamps(type: :utc_datetime)
   end
@@ -31,7 +33,7 @@ defmodule Postland.Accounts.User do
   """
   def registration_changeset(user, attrs, opts \\ []) do
     user
-    |> cast(attrs, [:username, :password])
+    |> cast(attrs, [:username, :password, :public_key, :private_key])
     |> validate_username()
     |> validate_password(opts)
   end

lib/postland_web/controllers/actor_controller.ex

@@ -0,0 +1,7 @@
+defmodule PostlandWeb.ActorController do
+  use PostlandWeb, :controller
+
+  def get(conn, _params) do
+    render(conn, :actor, %{})
+  end
+end

lib/postland_web/controllers/actor_json.ex

@@ -0,0 +1,25 @@
+defmodule PostlandWeb.ActorJSON do
+  use Phoenix.VerifiedRoutes, endpoint: PostlandWeb.Endpoint, router: PostlandWeb.Router
+
+  alias Postland.Accounts
+
+  def render("actor.json", _assigns) do
+    user = Accounts.solo_user()
+
+    %{
+      "@context" => [
+        "https://www.w3.org/ns/activitystreams",
+        "https://w3id.org/security/v1"
+      ],
+      "id" => url(~p"/actor"),
+      "type" => "Person",
+      "preferredUsername" => user.username,
+      "inbox" => url(~p"/inbox"),
+      "publicKey" => %{
+        "id" => url(~p"/actor#main-key"),
+        "owner" => url(~p"/actor"),
+        "publicKeyPem" => user.public_key
+      }
+    }
+  end
+end

lib/postland_web/controllers/webfinger_controller.ex

@@ -0,0 +1,9 @@
+defmodule PostlandWeb.WebfingerController do
+  use PostlandWeb, :controller
+
+  alias Postland.Accounts
+
+  def get(conn, _params) do
+    render(conn, :webfinger, %{})
+  end
+end

lib/postland_web/controllers/webfinger_json.ex

@@ -0,0 +1,21 @@
+defmodule PostlandWeb.WebfingerJSON do
+  use Phoenix.VerifiedRoutes, endpoint: PostlandWeb.Endpoint, router: PostlandWeb.Router
+
+  alias Postland.Accounts
+
+  def render("webfinger.json", _assigns) do
+    user = Accounts.solo_user()
+
+    # TODO: Check that the host here is correct after deploy
+    %{
+      subject: "acct:#{user.username}@#{PostlandWeb.Endpoint.host()}",
+      links: [
+        %{
+          "rel" => "self",
+          "type" => "application/activity+json",
+          "href" => url(~p"/actor")
+        }
+      ]
+    }
+  end
+end

lib/postland_web/router.ex

@@ -21,6 +21,14 @@ defmodule PostlandWeb.Router do
     plug PostlandWeb.Plugs.RedirectIfNotSetup
   end
 
+  scope "/", PostlandWeb do
+    pipe_through [:api]
+
+    get "/.well-known/webfinger", WebfingerController, :get
+
+    get "/actor", ActorController, :get
+  end
+
   scope "/", PostlandWeb do
     pipe_through [:browser, :redirect_if_not_set_up]
 
@@ -55,9 +63,7 @@ defmodule PostlandWeb.Router do
 
     live_session :redirect_if_user_is_authenticated,
       on_mount: [{PostlandWeb.UserAuth, :redirect_if_user_is_authenticated}] do
-      live "/users/register", UserRegistrationLive, :new
       live "/users/log_in", UserLoginLive, :new
-      live "/users/reset_password/:token", UserResetPasswordLive, :edit
     end
 
     post "/users/log_in", UserSessionController, :create

priv/repo/migrations/20240921235213_add_keys_to_user.exs

@@ -0,0 +1,10 @@
+defmodule Postland.Repo.Migrations.AddKeysToUser do
+  use Ecto.Migration
+
+  def change do
+    alter table("users") do
+      add :private_key, :text, null: false
+      add :public_key, :text, null: false
+    end
+  end
+end