diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/pleroma/constants.ex | 5 | ||||
| -rw-r--r-- | lib/pleroma/web/activity_pub/mrf/remote_report_policy.ex | 118 | ||||
| -rw-r--r-- | lib/pleroma/web/activity_pub/object_validator.ex | 12 |
3 files changed, 135 insertions, 0 deletions
diff --git a/lib/pleroma/constants.ex b/lib/pleroma/constants.ex index 5268ebe7a..2828c79a9 100644 --- a/lib/pleroma/constants.ex +++ b/lib/pleroma/constants.ex @@ -87,6 +87,7 @@ defmodule Pleroma.Constants do const(activity_types, do: [ + "Block", "Create", "Update", "Delete", @@ -115,6 +116,10 @@ defmodule Pleroma.Constants do ] ) + const(object_types, + do: ~w[Event Question Answer Audio Video Image Article Note Page ChatMessage] + ) + # basic regex, just there to weed out potential mistakes # https://datatracker.ietf.org/doc/html/rfc2045#section-5.1 const(mime_regex, diff --git a/lib/pleroma/web/activity_pub/mrf/remote_report_policy.ex b/lib/pleroma/web/activity_pub/mrf/remote_report_policy.ex new file mode 100644 index 000000000..fa0610bf1 --- /dev/null +++ b/lib/pleroma/web/activity_pub/mrf/remote_report_policy.ex @@ -0,0 +1,118 @@ +defmodule Pleroma.Web.ActivityPub.MRF.RemoteReportPolicy do + @moduledoc "Drop remote reports if they don't contain enough information." + @behaviour Pleroma.Web.ActivityPub.MRF.Policy + + alias Pleroma.Config + + @impl true + def filter(%{"type" => "Flag"} = object) do + with {_, false} <- {:local, local?(object)}, + {:ok, _} <- maybe_reject_all(object), + {:ok, _} <- maybe_reject_anonymous(object), + {:ok, _} <- maybe_reject_third_party(object), + {:ok, _} <- maybe_reject_empty_message(object) do + {:ok, object} + else + {:local, true} -> {:ok, object} + {:reject, message} -> {:reject, message} + error -> {:reject, error} + end + end + + def filter(object), do: {:ok, object} + + defp maybe_reject_all(object) do + if Config.get([:mrf_remote_report, :reject_all]) do + {:reject, "[RemoteReportPolicy] Remote report"} + else + {:ok, object} + end + end + + defp maybe_reject_anonymous(%{"actor" => actor} = object) do + with true <- Config.get([:mrf_remote_report, :reject_anonymous]), + %URI{path: "/actor"} <- URI.parse(actor) do + {:reject, "[RemoteReportPolicy] Anonymous: #{actor}"} + else + _ -> {:ok, object} + end + end + + defp maybe_reject_third_party(%{"object" => objects} = object) do + {_, to} = + case objects do + [head | tail] when is_binary(head) -> {tail, head} + s when is_binary(s) -> {[], s} + _ -> {[], ""} + end + + with true <- Config.get([:mrf_remote_report, :reject_third_party]), + false <- String.starts_with?(to, Pleroma.Web.Endpoint.url()) do + {:reject, "[RemoteReportPolicy] Third-party: #{to}"} + else + _ -> {:ok, object} + end + end + + defp maybe_reject_empty_message(%{"content" => content} = object) + when is_binary(content) and content != "" do + {:ok, object} + end + + defp maybe_reject_empty_message(object) do + if Config.get([:mrf_remote_report, :reject_empty_message]) do + {:reject, ["RemoteReportPolicy] No content"]} + else + {:ok, object} + end + end + + defp local?(%{"actor" => actor}) do + String.starts_with?(actor, Pleroma.Web.Endpoint.url()) + end + + @impl true + def describe do + mrf_remote_report = + Config.get(:mrf_remote_report) + |> Enum.into(%{}) + + {:ok, %{mrf_remote_report: mrf_remote_report}} + end + + @impl true + def config_description do + %{ + key: :mrf_remote_report, + related_policy: "Pleroma.Web.ActivityPub.MRF.RemoteReportPolicy", + label: "MRF Remote Report", + description: "Drop remote reports if they don't contain enough information.", + children: [ + %{ + key: :reject_all, + type: :boolean, + description: "Reject all remote reports? (this option takes precedence)", + suggestions: [false] + }, + %{ + key: :reject_anonymous, + type: :boolean, + description: "Reject anonymous remote reports?", + suggestions: [true] + }, + %{ + key: :reject_third_party, + type: :boolean, + description: "Reject reports on users from third-party instances?", + suggestions: [true] + }, + %{ + key: :reject_empty_message, + type: :boolean, + description: "Reject remote reports with no message?", + suggestions: [true] + } + ] + } + end +end diff --git a/lib/pleroma/web/activity_pub/object_validator.ex b/lib/pleroma/web/activity_pub/object_validator.ex index b3043b93a..35774d410 100644 --- a/lib/pleroma/web/activity_pub/object_validator.ex +++ b/lib/pleroma/web/activity_pub/object_validator.ex @@ -11,6 +11,8 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidator do @behaviour Pleroma.Web.ActivityPub.ObjectValidator.Validating + import Pleroma.Constants, only: [activity_types: 0, object_types: 0] + alias Pleroma.Activity alias Pleroma.EctoType.ActivityPub.ObjectValidators alias Pleroma.Object @@ -38,6 +40,16 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidator do @impl true def validate(object, meta) + # This overload works together with the InboxGuardPlug + # and ensures that we are not accepting any activity type + # that cannot pass InboxGuardPlug. + # If we want to support any more activity types, make sure to + # add it in Pleroma.Constants's activity_types or object_types, + # and, if applicable, allowed_activity_types_from_strangers. + def validate(%{"type" => type}, _meta) + when type not in activity_types() and type not in object_types(), + do: {:error, :not_allowed_object_type} + def validate(%{"type" => "Block"} = block_activity, meta) do with {:ok, block_activity} <- block_activity |