# Pleroma: A lightweight social networking server
-# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
+defmodule Pleroma.Web.Plug do
+ # Substitute for `call/2` which is defined with `use Pleroma.Web, :plug`
+ @callback perform(Plug.Conn.t(), Plug.opts()) :: Plug.Conn.t()
+end
+
defmodule Pleroma.Web do
@moduledoc """
A module that keeps using definitions for controllers,
below.
"""
+ alias Pleroma.Plugs.EnsureAuthenticatedPlug
+ alias Pleroma.Plugs.EnsurePublicOrAuthenticatedPlug
+ alias Pleroma.Plugs.ExpectAuthenticatedCheckPlug
+ alias Pleroma.Plugs.ExpectPublicOrAuthenticatedCheckPlug
+ alias Pleroma.Plugs.OAuthScopesPlug
+ alias Pleroma.Plugs.PlugHelper
+
def controller do
quote do
use Phoenix.Controller, namespace: Pleroma.Web
import Plug.Conn
+
import Pleroma.Web.Gettext
import Pleroma.Web.Router.Helpers
import Pleroma.Web.TranslationHelpers
defp set_put_layout(conn, _) do
put_layout(conn, Pleroma.Config.get(:app_layout, "app.html"))
end
+
+ # Marks plugs intentionally skipped and blocks their execution if present in plugs chain
+ defp skip_plug(conn, plug_modules) do
+ plug_modules
+ |> List.wrap()
+ |> Enum.reduce(
+ conn,
+ fn plug_module, conn ->
+ try do
+ plug_module.skip_plug(conn)
+ rescue
+ UndefinedFunctionError ->
+ raise "`#{plug_module}` is not skippable. Append `use Pleroma.Web, :plug` to its code."
+ end
+ end
+ )
+ end
+
+ # Executed just before actual controller action, invokes before-action hooks (callbacks)
+ defp action(conn, params) do
+ with %{halted: false} = conn <- maybe_drop_authentication_if_oauth_check_ignored(conn),
+ %{halted: false} = conn <- maybe_perform_public_or_authenticated_check(conn),
+ %{halted: false} = conn <- maybe_perform_authenticated_check(conn),
+ %{halted: false} = conn <- maybe_halt_on_missing_oauth_scopes_check(conn) do
+ super(conn, params)
+ end
+ end
+
+ # For non-authenticated API actions, drops auth info if OAuth scopes check was ignored
+ # (neither performed nor explicitly skipped)
+ defp maybe_drop_authentication_if_oauth_check_ignored(conn) do
+ if PlugHelper.plug_called?(conn, ExpectPublicOrAuthenticatedCheckPlug) and
+ not PlugHelper.plug_called_or_skipped?(conn, OAuthScopesPlug) do
+ OAuthScopesPlug.drop_auth_info(conn)
+ else
+ conn
+ end
+ end
+
+ # Ensures instance is public -or- user is authenticated if such check was scheduled
+ defp maybe_perform_public_or_authenticated_check(conn) do
+ if PlugHelper.plug_called?(conn, ExpectPublicOrAuthenticatedCheckPlug) do
+ EnsurePublicOrAuthenticatedPlug.call(conn, %{})
+ else
+ conn
+ end
+ end
+
+ # Ensures user is authenticated if such check was scheduled
+ # Note: runs prior to action even if it was already executed earlier in plug chain
+ # (since OAuthScopesPlug has option of proceeding unauthenticated)
+ defp maybe_perform_authenticated_check(conn) do
+ if PlugHelper.plug_called?(conn, ExpectAuthenticatedCheckPlug) do
+ EnsureAuthenticatedPlug.call(conn, %{})
+ else
+ conn
+ end
+ end
+
+ # Halts if authenticated API action neither performs nor explicitly skips OAuth scopes check
+ defp maybe_halt_on_missing_oauth_scopes_check(conn) do
+ if PlugHelper.plug_called?(conn, ExpectAuthenticatedCheckPlug) and
+ not PlugHelper.plug_called_or_skipped?(conn, OAuthScopesPlug) do
+ conn
+ |> render_error(
+ :forbidden,
+ "Security violation: OAuth scopes check was neither handled nor explicitly skipped."
+ )
+ |> halt()
+ else
+ conn
+ end
+ end
end
end
end
end
+ def plug do
+ quote do
+ @behaviour Pleroma.Web.Plug
+ @behaviour Plug
+
+ @doc """
+ Marks a plug intentionally skipped and blocks its execution if it's present in plugs chain.
+ """
+ def skip_plug(conn) do
+ PlugHelper.append_to_private_list(
+ conn,
+ PlugHelper.skipped_plugs_list_id(),
+ __MODULE__
+ )
+ end
+
+ @impl Plug
+ @doc """
+ If marked as skipped, returns `conn`, otherwise calls `perform/2`.
+ Note: multiple invocations of the same plug (with different or same options) are allowed.
+ """
+ def call(%Plug.Conn{} = conn, options) do
+ if PlugHelper.plug_skipped?(conn, __MODULE__) do
+ conn
+ else
+ conn =
+ PlugHelper.append_to_private_list(
+ conn,
+ PlugHelper.called_plugs_list_id(),
+ __MODULE__
+ )
+
+ apply(__MODULE__, :perform, [conn, options])
+ end
+ end
+ end
+ end
+
@doc """
When used, dispatch to the appropriate controller/view/etc.
"""