Verify link ownership with rel="me"

Signed-off-by: marcin mikołajczak <git@mkljczk.pl>

changelog.d/link-verification.add

@@ -0,0 +1 @@
+Verify profile link ownership with rel="me"

lib/pleroma/user.ex

@@ -8,6 +8,7 @@ defmodule Pleroma.User do
   import Ecto.Changeset
   import Ecto.Query
   import Ecto, only: [assoc: 2]
+  import Pleroma.Web.Utils.Guards, only: [not_empty_string: 1]
 
   alias Ecto.Multi
   alias Pleroma.Activity
@@ -595,9 +596,23 @@ def update_changeset(struct, params \\ %{}) do
 
   defp put_fields(changeset) do
     if raw_fields = get_change(changeset, :raw_fields) do
+      old_fields = changeset.data.raw_fields
+
       raw_fields =
         raw_fields
         |> Enum.filter(fn %{"name" => n} -> n != "" end)
+        |> Enum.map(fn field ->
+          previous =
+            old_fields
+            |> Enum.find(fn %{"value" => value} -> field["value"] == value end)
+
+          if previous && Map.has_key?(previous, "verified_at") do
+            field
+            |> Map.put("verified_at", previous["verified_at"])
+          else
+            field
+          end
+        end)
 
       fields =
         raw_fields
@@ -1198,6 +1213,10 @@ def update_and_set_cache(struct, params) do
 
   def update_and_set_cache(changeset) do
     with {:ok, user} <- Repo.update(changeset, stale_error_field: :id) do
+      if get_change(changeset, :raw_fields) do
+        BackgroundWorker.enqueue("verify_fields_links", %{"user_id" => user.id})
+      end
+
       set_cache(user)
     end
   end
@@ -1970,8 +1989,47 @@ def perform(:delete, %User{} = user) do
     maybe_delete_from_db(user)
   end
 
+  def perform(:verify_fields_links, user) do
+    profile_urls = [user.ap_id]
+
+    fields =
+      user.raw_fields
+      |> Enum.map(&verify_field_link(&1, profile_urls))
+
+    changeset =
+      user
+      |> update_changeset(%{raw_fields: fields})
+
+    with {:ok, user} <- Repo.update(changeset, stale_error_field: :id) do
+      set_cache(user)
+    end
+  end
+
   def perform(:set_activation_async, user, status), do: set_activation(user, status)
 
+  defp verify_field_link(field, profile_urls) do
+    verified_at =
+      with %{"value" => value} <- field,
+           {:verified_at, nil} <- {:verified_at, Map.get(field, "verified_at")},
+           %{scheme: scheme, userinfo: nil, host: host}
+           when not_empty_string(host) and scheme in ["http", "https"] <-
+             URI.parse(value),
+           {:not_idn, true} <- {:not_idn, to_string(:idna.encode(host)) == host},
+           attr <- Pleroma.Web.RelMe.maybe_put_rel_me(value, profile_urls) do
+        if attr == "me" do
+          CommonUtils.to_masto_date(NaiveDateTime.utc_now())
+        end
+      else
+        {:verified_at, value} when not_empty_string(value) ->
+          value
+
+        _ ->
+          nil
+      end
+
+    Map.put(field, "verified_at", verified_at)
+  end
+
   @spec external_users_query() :: Ecto.Query.t()
   def external_users_query do
     User.Query.build(%{
@@ -2659,10 +2717,11 @@ def sanitize_html(%User{} = user) do
   # - display name
   def sanitize_html(%User{} = user, filter) do
     fields =
-      Enum.map(user.fields, fn %{"name" => name, "value" => value} ->
+      Enum.map(user.fields, fn %{"name" => name, "value" => value} = fields ->
         %{
           "name" => name,
-          "value" => HTML.filter_tags(value, Pleroma.HTML.Scrubber.LinksOnly)
+          "value" => HTML.filter_tags(value, Pleroma.HTML.Scrubber.LinksOnly),
+          "verified_at" => Map.get(fields, "verified_at")
         }
       end)
 

lib/pleroma/workers/background_worker.ex

@@ -40,6 +40,11 @@ def perform(%Job{
     Pleroma.FollowingRelationship.move_following(origin, target)
   end
 
+  def perform(%Job{args: %{"op" => "verify_fields_links", "user_id" => user_id}}) do
+    user = User.get_by_id(user_id)
+    User.perform(:verify_fields_links, user)
+  end
+
   def perform(%Job{args: %{"op" => "delete_instance", "host" => host}}) do
     Instance.perform(:delete_instance, host)
   end

test/pleroma/user_test.exs

@@ -2913,4 +2913,29 @@ test "it doesn't pin users you do not follow" do
       refute User.endorses?(user, pinned_user)
     end
   end
+
+  test "it checks fields links for a backlink" do
+    user = insert(:user, ap_id: "https://social.example.org/users/lain")
+
+    fields = [
+      %{"name" => "Link", "value" => "http://example.com/rel_me/null"},
+      %{"name" => "Verified link", "value" => "http://example.com/rel_me/link"},
+      %{"name" => "Not a link", "value" => "i'm not a link"}
+    ]
+
+    user
+    |> User.update_and_set_cache(%{raw_fields: fields})
+
+    ObanHelpers.perform_all()
+
+    user = User.get_cached_by_id(user.id)
+
+    assert [
+             %{"verified_at" => nil},
+             %{"verified_at" => verified_at},
+             %{"verified_at" => nil}
+           ] = user.fields
+
+    assert is_binary(verified_at)
+  end
 end

test/pleroma/web/mastodon_api/update_credentials_test.exs

@@ -502,10 +502,15 @@ test "update fields", %{conn: conn} do
         |> json_response_and_validate_schema(200)
 
       assert account_data["fields"] == [
-               %{"name" => "<a href=\"http://google.com\">foo</a>", "value" => "bar"},
+               %{
+                 "name" => "<a href=\"http://google.com\">foo</a>",
+                 "value" => "bar",
+                 "verified_at" => nil
+               },
                %{
                  "name" => "link.io",
-                 "value" => ~S(<a href="http://cofe.io" rel="ugc">cofe.io</a>)
+                 "value" => ~S(<a href="http://cofe.io" rel="ugc">cofe.io</a>),
+                 "verified_at" => nil
                }
              ]
 
@@ -564,8 +569,8 @@ test "emojis in fields labels", %{conn: conn} do
         |> json_response_and_validate_schema(200)
 
       assert account_data["fields"] == [
-               %{"name" => ":firefox:", "value" => "is best 2hu"},
-               %{"name" => "they wins", "value" => ":blank:"}
+               %{"name" => ":firefox:", "value" => "is best 2hu", "verified_at" => nil},
+               %{"name" => "they wins", "value" => ":blank:", "verified_at" => nil}
              ]
 
       assert account_data["source"]["fields"] == [
@@ -593,10 +598,11 @@ test "update fields via x-www-form-urlencoded", %{conn: conn} do
         |> json_response_and_validate_schema(200)
 
       assert account["fields"] == [
-               %{"name" => "foo", "value" => "bar"},
+               %{"name" => "foo", "value" => "bar", "verified_at" => nil},
                %{
                  "name" => "link",
-                 "value" => ~S(<a href="http://cofe.io" rel="ugc">http://cofe.io</a>)
+                 "value" => ~S(<a href="http://cofe.io" rel="ugc">http://cofe.io</a>),
+                 "verified_at" => nil
                }
              ]
 
@@ -618,7 +624,7 @@ test "update fields with empty name", %{conn: conn} do
         |> json_response_and_validate_schema(200)
 
       assert account["fields"] == [
-               %{"name" => "foo", "value" => ""}
+               %{"name" => "foo", "value" => "", "verified_at" => nil}
              ]
     end