# Pleroma: A lightweight social networking server # 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, views and so on. This can be used in your application as: use Pleroma.Web, :controller use Pleroma.Web, :view The definitions below will be executed for every view, controller, etc, so keep them short and clean, focused on imports, uses and aliases. Do NOT define functions inside the quoted expressions 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 plug(:set_put_layout) 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 def view do quote do use Phoenix.View, root: "lib/pleroma/web/templates", namespace: Pleroma.Web # Import convenience functions from controllers import Phoenix.Controller, only: [get_csrf_token: 0, get_flash: 2, view_module: 1] import Pleroma.Web.ErrorHelpers import Pleroma.Web.Gettext import Pleroma.Web.Router.Helpers require Logger @doc "Same as `render/3` but wrapped in a rescue block" def safe_render(view, template, assigns \\ %{}) do Phoenix.View.render(view, template, assigns) rescue error -> Logger.error( "#{__MODULE__} failed to render #{inspect({view, template})}\n" <> Exception.format(:error, error, __STACKTRACE__) ) nil end @doc """ Same as `render_many/4` but wrapped in rescue block. """ def safe_render_many(collection, view, template, assigns \\ %{}) do Enum.map(collection, fn resource -> as = Map.get(assigns, :as) || view.__resource__ assigns = Map.put(assigns, as, resource) safe_render(view, template, assigns) end) |> Enum.filter(& &1) end end end def router do quote do use Phoenix.Router # credo:disable-for-next-line Credo.Check.Consistency.MultiAliasImportRequireUse import Plug.Conn import Phoenix.Controller end end def channel do quote do # credo:disable-for-next-line Credo.Check.Consistency.MultiAliasImportRequireUse use Phoenix.Channel import Pleroma.Web.Gettext 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 """ Before-plug hook that * ensures the plug is not skipped * processes `:if_func` / `:unless_func` functional pre-run conditions * adds plug to the list of called plugs and calls `perform/2` if checks are passed 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__) || (options[:if_func] && !options[:if_func].(conn)) || (options[:unless_func] && options[:unless_func].(conn)) 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. """ defmacro __using__(which) when is_atom(which) do apply(__MODULE__, which, []) end def base_url do Pleroma.Web.Endpoint.url() end end