Merge branch 'fix/ap-hide-follows' into 'develop'

ActivityPub Controller: Change how hiding follows/followers is represented

See merge request pleroma/pleroma!1406

6 files changed, 160 insertions, 32 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 942733ab6..405b7680c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - **Breaking:** Configuration: A setting to explicitly disable the mailer was added, defaulting to true, if you are using a mailer add `config :pleroma, Pleroma.Emails.Mailer, enabled: true` to your config
 - Configuration: OpenGraph and TwitterCard providers enabled by default
 - Configuration: Filter.AnonymizeFilename added ability to retain file extension with custom text
+- Federation: Return 403 errors when trying to request pages from a user's follower/following collections if they have `hide_followers`/`hide_follows` set
 - NodeInfo: Return `skipThreadContainment` in `metadata` for the `skip_thread_containment` option
 
 ### Fixed
@@ -16,6 +17,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Mastodon API: Handling of search timeouts (`/api/v1/search` and `/api/v2/search`)
 - Mastodon API: Embedded relationships not being properly rendered in the Account entity of Status entity
 - Mastodon API: Add `account_id`, `type`, `offset`, and `limit` to search API (`/api/v1/search` and `/api/v2/search`)
+- ActivityPub C2S: follower/following collection pages being inaccessible even when authentifucated if `hide_followers`/ `hide_follows` was set
 
 ### Added
 - MRF: Support for priming the mediaproxy cache (`Pleroma.Web.ActivityPub.MRF.MediaProxyWarmingPolicy`)
diff --git a/lib/pleroma/web/activity_pub/activity_pub_controller.ex b/lib/pleroma/web/activity_pub/activity_pub_controller.ex
index cf5176201..e2af4ad1a 100644
--- a/lib/pleroma/web/activity_pub/activity_pub_controller.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub_controller.ex
@@ -103,43 +103,57 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubController do
     end
   end
 
-  def following(conn, %{"nickname" => nickname, "page" => page}) do
+  def following(%{assigns: %{user: for_user}} = conn, %{"nickname" => nickname, "page" => page}) do
     with %User{} = user <- User.get_cached_by_nickname(nickname),
-         {:ok, user} <- User.ensure_keys_present(user) do
+         {user, for_user} <- ensure_user_keys_present_and_maybe_refresh_for_user(user, for_user),
+         {:show_follows, true} <-
+           {:show_follows, (for_user && for_user == user) || !user.info.hide_follows} do
       {page, _} = Integer.parse(page)
 
       conn
       |> put_resp_header("content-type", "application/activity+json")
-      |> json(UserView.render("following.json", %{user: user, page: page}))
+      |> json(UserView.render("following.json", %{user: user, page: page, for: for_user}))
+    else
+      {:show_follows, _} ->
+        conn
+        |> put_resp_header("content-type", "application/activity+json")
+        |> send_resp(403, "")
     end
   end
 
-  def following(conn, %{"nickname" => nickname}) do
+  def following(%{assigns: %{user: for_user}} = conn, %{"nickname" => nickname}) do
     with %User{} = user <- User.get_cached_by_nickname(nickname),
-         {:ok, user} <- User.ensure_keys_present(user) do
+         {user, for_user} <- ensure_user_keys_present_and_maybe_refresh_for_user(user, for_user) do
       conn
       |> put_resp_header("content-type", "application/activity+json")
-      |> json(UserView.render("following.json", %{user: user}))
+      |> json(UserView.render("following.json", %{user: user, for: for_user}))
     end
   end
 
-  def followers(conn, %{"nickname" => nickname, "page" => page}) do
+  def followers(%{assigns: %{user: for_user}} = conn, %{"nickname" => nickname, "page" => page}) do
     with %User{} = user <- User.get_cached_by_nickname(nickname),
-         {:ok, user} <- User.ensure_keys_present(user) do
+         {user, for_user} <- ensure_user_keys_present_and_maybe_refresh_for_user(user, for_user),
+         {:show_followers, true} <-
+           {:show_followers, (for_user && for_user == user) || !user.info.hide_followers} do
       {page, _} = Integer.parse(page)
 
       conn
       |> put_resp_header("content-type", "application/activity+json")
-      |> json(UserView.render("followers.json", %{user: user, page: page}))
+      |> json(UserView.render("followers.json", %{user: user, page: page, for: for_user}))
+    else
+      {:show_followers, _} ->
+        conn
+        |> put_resp_header("content-type", "application/activity+json")
+        |> send_resp(403, "")
     end
   end
 
-  def followers(conn, %{"nickname" => nickname}) do
+  def followers(%{assigns: %{user: for_user}} = conn, %{"nickname" => nickname}) do
     with %User{} = user <- User.get_cached_by_nickname(nickname),
-         {:ok, user} <- User.ensure_keys_present(user) do
+         {user, for_user} <- ensure_user_keys_present_and_maybe_refresh_for_user(user, for_user) do
       conn
       |> put_resp_header("content-type", "application/activity+json")
-      |> json(UserView.render("followers.json", %{user: user}))
+      |> json(UserView.render("followers.json", %{user: user, for: for_user}))
     end
   end
 
@@ -325,4 +339,17 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubController do
 
     conn
   end
+
+  defp ensure_user_keys_present_and_maybe_refresh_for_user(user, for_user) do
+    {:ok, new_user} = User.ensure_keys_present(user)
+
+    for_user =
+      if new_user != user and match?(%User{}, for_user) do
+        User.get_cached_by_nickname(for_user.nickname)
+      else
+        for_user
+      end
+
+    {new_user, for_user}
+  end
 end
diff --git a/lib/pleroma/web/activity_pub/views/user_view.ex b/lib/pleroma/web/activity_pub/views/user_view.ex
index 327e0e05b..d9c1bcb2c 100644
--- a/lib/pleroma/web/activity_pub/views/user_view.ex
+++ b/lib/pleroma/web/activity_pub/views/user_view.ex
@@ -98,29 +98,31 @@ defmodule Pleroma.Web.ActivityPub.UserView do
     |> Map.merge(Utils.make_json_ld_header())
   end
 
-  def render("following.json", %{user: user, page: page}) do
+  def render("following.json", %{user: user, page: page} = opts) do
+    showing = (opts[:for] && opts[:for] == user) || !user.info.hide_follows
     query = User.get_friends_query(user)
     query = from(user in query, select: [:ap_id])
     following = Repo.all(query)
 
     total =
-      if !user.info.hide_follows do
+      if showing do
         length(following)
       else
         0
       end
 
-    collection(following, "#{user.ap_id}/following", page, !user.info.hide_follows, total)
+    collection(following, "#{user.ap_id}/following", page, showing, total)
     |> Map.merge(Utils.make_json_ld_header())
   end
 
-  def render("following.json", %{user: user}) do
+  def render("following.json", %{user: user} = opts) do
+    showing = (opts[:for] && opts[:for] == user) || !user.info.hide_follows
     query = User.get_friends_query(user)
     query = from(user in query, select: [:ap_id])
     following = Repo.all(query)
 
     total =
-      if !user.info.hide_follows do
+      if showing do
         length(following)
       else
         0
@@ -130,34 +132,43 @@ defmodule Pleroma.Web.ActivityPub.UserView do
       "id" => "#{user.ap_id}/following",
       "type" => "OrderedCollection",
       "totalItems" => total,
-      "first" => collection(following, "#{user.ap_id}/following", 1, !user.info.hide_follows)
+      "first" =>
+        if showing do
+          collection(following, "#{user.ap_id}/following", 1, !user.info.hide_follows)
+        else
+          "#{user.ap_id}/following?page=1"
+        end
     }
     |> Map.merge(Utils.make_json_ld_header())
   end
 
-  def render("followers.json", %{user: user, page: page}) do
+  def render("followers.json", %{user: user, page: page} = opts) do
+    showing = (opts[:for] && opts[:for] == user) || !user.info.hide_followers
+
     query = User.get_followers_query(user)
     query = from(user in query, select: [:ap_id])
     followers = Repo.all(query)
 
     total =
-      if !user.info.hide_followers do
+      if showing do
         length(followers)
       else
         0
       end
 
-    collection(followers, "#{user.ap_id}/followers", page, !user.info.hide_followers, total)
+    collection(followers, "#{user.ap_id}/followers", page, showing, total)
     |> Map.merge(Utils.make_json_ld_header())
   end
 
-  def render("followers.json", %{user: user}) do
+  def render("followers.json", %{user: user} = opts) do
+    showing = (opts[:for] && opts[:for] == user) || !user.info.hide_followers
+
     query = User.get_followers_query(user)
     query = from(user in query, select: [:ap_id])
     followers = Repo.all(query)
 
     total =
-      if !user.info.hide_followers do
+      if showing do
         length(followers)
       else
         0
@@ -168,7 +179,11 @@ defmodule Pleroma.Web.ActivityPub.UserView do
       "type" => "OrderedCollection",
       "totalItems" => total,
       "first" =>
-        collection(followers, "#{user.ap_id}/followers", 1, !user.info.hide_followers, total)
+        if showing do
+          collection(followers, "#{user.ap_id}/followers", 1, showing, total)
+        else
+          "#{user.ap_id}/followers?page=1"
+        end
     }
     |> Map.merge(Utils.make_json_ld_header())
   end
diff --git a/lib/pleroma/web/router.ex b/lib/pleroma/web/router.ex
index a3b6ea366..3e5142e8a 100644
--- a/lib/pleroma/web/router.ex
+++ b/lib/pleroma/web/router.ex
@@ -623,8 +623,6 @@ defmodule Pleroma.Web.Router do
     # XXX: not really ostatus
     pipe_through(:ostatus)
 
-    get("/users/:nickname/followers", ActivityPubController, :followers)
-    get("/users/:nickname/following", ActivityPubController, :following)
     get("/users/:nickname/outbox", ActivityPubController, :outbox)
     get("/objects/:uuid/likes", ActivityPubController, :object_likes)
   end
@@ -656,6 +654,12 @@ defmodule Pleroma.Web.Router do
       pipe_through(:oauth_write)
       post("/users/:nickname/outbox", ActivityPubController, :update_outbox)
     end
+
+    scope [] do
+      pipe_through(:oauth_read_or_public)
+      get("/users/:nickname/followers", ActivityPubController, :followers)
+      get("/users/:nickname/following", ActivityPubController, :following)
+    end
   end
 
   scope "/relay", Pleroma.Web.ActivityPub do
diff --git a/test/web/activity_pub/activity_pub_controller_test.exs b/test/web/activity_pub/activity_pub_controller_test.exs
index 1f8eb9d71..452172bb4 100644
--- a/test/web/activity_pub/activity_pub_controller_test.exs
+++ b/test/web/activity_pub/activity_pub_controller_test.exs
@@ -12,6 +12,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubControllerTest do
   alias Pleroma.Web.ActivityPub.ObjectView
   alias Pleroma.Web.ActivityPub.UserView
   alias Pleroma.Web.ActivityPub.Utils
+  alias Pleroma.Web.CommonAPI
 
   setup_all do
     Tesla.Mock.mock_global(fn env -> apply(HttpRequestMock, :request, [env]) end)
@@ -551,7 +552,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubControllerTest do
       assert result["first"]["orderedItems"] == [user.ap_id]
     end
 
-    test "it returns returns empty if the user has 'hide_followers' set", %{conn: conn} do
+    test "it returns returns a uri if the user has 'hide_followers' set", %{conn: conn} do
       user = insert(:user)
       user_two = insert(:user, %{info: %{hide_followers: true}})
       User.follow(user, user_two)
@@ -561,8 +562,35 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubControllerTest do
         |> get("/users/#{user_two.nickname}/followers")
         |> json_response(200)
 
-      assert result["first"]["orderedItems"] == []
-      assert result["totalItems"] == 0
+      assert is_binary(result["first"])
+    end
+
+    test "it returns a 403 error on pages, if the user has 'hide_followers' set and the request is not authenticated",
+         %{conn: conn} do
+      user = insert(:user, %{info: %{hide_followers: true}})
+
+      result =
+        conn
+        |> get("/users/#{user.nickname}/followers?page=1")
+
+      assert result.status == 403
+      assert result.resp_body == ""
+    end
+
+    test "it renders the page, if the user has 'hide_followers' set and the request is authenticated with the same user",
+         %{conn: conn} do
+      user = insert(:user, %{info: %{hide_followers: true}})
+      other_user = insert(:user)
+      {:ok, _other_user, user, _activity} = CommonAPI.follow(other_user, user)
+
+      result =
+        conn
+        |> assign(:user, user)
+        |> get("/users/#{user.nickname}/followers?page=1")
+        |> json_response(200)
+
+      assert result["totalItems"] == 1
+      assert result["orderedItems"] == [other_user.ap_id]
     end
 
     test "it works for more than 10 users", %{conn: conn} do
@@ -606,7 +634,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubControllerTest do
       assert result["first"]["orderedItems"] == [user_two.ap_id]
     end
 
-    test "it returns returns empty if the user has 'hide_follows' set", %{conn: conn} do
+    test "it returns a uri if the user has 'hide_follows' set", %{conn: conn} do
       user = insert(:user, %{info: %{hide_follows: true}})
       user_two = insert(:user)
       User.follow(user, user_two)
@@ -616,8 +644,35 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubControllerTest do
         |> get("/users/#{user.nickname}/following")
         |> json_response(200)
 
-      assert result["first"]["orderedItems"] == []
-      assert result["totalItems"] == 0
+      assert is_binary(result["first"])
+    end
+
+    test "it returns a 403 error on pages, if the user has 'hide_follows' set and the request is not authenticated",
+         %{conn: conn} do
+      user = insert(:user, %{info: %{hide_follows: true}})
+
+      result =
+        conn
+        |> get("/users/#{user.nickname}/following?page=1")
+
+      assert result.status == 403
+      assert result.resp_body == ""
+    end
+
+    test "it renders the page, if the user has 'hide_follows' set and the request is authenticated with the same user",
+         %{conn: conn} do
+      user = insert(:user, %{info: %{hide_follows: true}})
+      other_user = insert(:user)
+      {:ok, user, _other_user, _activity} = CommonAPI.follow(user, other_user)
+
+      result =
+        conn
+        |> assign(:user, user)
+        |> get("/users/#{user.nickname}/following?page=1")
+        |> json_response(200)
+
+      assert result["totalItems"] == 1
+      assert result["orderedItems"] == [other_user.ap_id]
     end
 
     test "it works for more than 10 users", %{conn: conn} do
diff --git a/test/web/activity_pub/views/user_view_test.exs b/test/web/activity_pub/views/user_view_test.exs
index 969860c4c..86254117f 100644
--- a/test/web/activity_pub/views/user_view_test.exs
+++ b/test/web/activity_pub/views/user_view_test.exs
@@ -8,6 +8,7 @@ defmodule Pleroma.Web.ActivityPub.UserViewTest do
 
   alias Pleroma.User
   alias Pleroma.Web.ActivityPub.UserView
+  alias Pleroma.Web.CommonAPI
 
   test "Renders a user, including the public key" do
     user = insert(:user)
@@ -82,4 +83,28 @@ defmodule Pleroma.Web.ActivityPub.UserViewTest do
       refute result["endpoints"]["oauthTokenEndpoint"]
     end
   end
+
+  describe "followers" do
+    test "sets totalItems to zero when followers are hidden" do
+      user = insert(:user)
+      other_user = insert(:user)
+      {:ok, _other_user, user, _activity} = CommonAPI.follow(other_user, user)
+      assert %{"totalItems" => 1} = UserView.render("followers.json", %{user: user})
+      info = Map.put(user.info, :hide_followers, true)
+      user = Map.put(user, :info, info)
+      assert %{"totalItems" => 0} = UserView.render("followers.json", %{user: user})
+    end
+  end
+
+  describe "following" do
+    test "sets totalItems to zero when follows are hidden" do
+      user = insert(:user)
+      other_user = insert(:user)
+      {:ok, user, _other_user, _activity} = CommonAPI.follow(user, other_user)
+      assert %{"totalItems" => 1} = UserView.render("following.json", %{user: user})
+      info = Map.put(user.info, :hide_follows, true)
+      user = Map.put(user, :info, info)
+      assert %{"totalItems" => 0} = UserView.render("following.json", %{user: user})
+    end
+  end
 end