git.squeep.com Git - akkoma/blob - lib/pleroma/web/twitter_api/controllers/remote_follow_controller.ex

   1 # Pleroma: A lightweight social networking server
   2 # Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
   3 # SPDX-License-Identifier: AGPL-3.0-only
   4
   5 defmodule Pleroma.Web.TwitterAPI.RemoteFollowController do
   6   use Pleroma.Web, :controller
   7
   8   require Logger
   9
  10   alias Pleroma.Activity
  11   alias Pleroma.MFA
  12   alias Pleroma.Object.Fetcher
  13   alias Pleroma.User
  14   alias Pleroma.Web.Auth.Authenticator
  15   alias Pleroma.Web.Auth.TOTPAuthenticator
  16   alias Pleroma.Web.CommonAPI
  17
  18   @status_types ["Article", "Event", "Note", "Video", "Page", "Question"]
  19
  20   plug(Pleroma.Web.Plugs.FederatingPlug)
  21
  22   # Note: follower can submit the form (with password auth) not being signed in (having no token)
  23   plug(
  24     Pleroma.Web.Plugs.OAuthScopesPlug,
  25     %{fallback: :proceed_unauthenticated, scopes: ["follow", "write:follows"]}
  26     when action in [:do_follow]
  27   )
  28
  29   # GET /ostatus_subscribe
  30   #
  31   def follow(%{assigns: %{user: user}} = conn, %{"acct" => acct}) do
  32     case is_status?(acct) do
  33       true -> follow_status(conn, user, acct)
  34       _ -> follow_account(conn, user, acct)
  35     end
  36   end
  37
  38   defp follow_status(conn, _user, acct) do
  39     with {:ok, object} <- Fetcher.fetch_object_from_id(acct),
  40          %Activity{id: activity_id} <- Activity.get_create_by_object_ap_id(object.data["id"]) do
  41       redirect(conn, to: Routes.o_status_path(conn, :notice, activity_id))
  42     else
  43       error ->
  44         handle_follow_error(conn, error)
  45     end
  46   end
  47
  48   defp follow_account(conn, user, acct) do
  49     with {:ok, followee} <- User.get_or_fetch(acct) do
  50       render(conn, follow_template(user), %{error: false, followee: followee, acct: acct})
  51     else
  52       {:error, _reason} ->
  53         render(conn, follow_template(user), %{error: :error})
  54     end
  55   end
  56
  57   defp follow_template(%User{} = _user), do: "follow.html"
  58   defp follow_template(_), do: "follow_login.html"
  59
  60   defp is_status?(acct) do
  61     case Fetcher.fetch_and_contain_remote_object_from_id(acct) do
  62       {:ok, %{"type" => type}} when type in @status_types ->
  63         true
  64
  65       _ ->
  66         false
  67     end
  68   end
  69
  70   # POST  /ostatus_subscribe
  71   #
  72   # adds a remote account in followers if user already is signed in.
  73   #
  74   def do_follow(%{assigns: %{user: %User{} = user}} = conn, %{"user" => %{"id" => id}}) do
  75     with {:fetch_user, %User{} = followee} <- {:fetch_user, User.get_cached_by_id(id)},
  76          {:ok, _, _, _} <- CommonAPI.follow(user, followee) do
  77       redirect(conn, to: "/users/#{followee.id}")
  78     else
  79       error ->
  80         handle_follow_error(conn, error)
  81     end
  82   end
  83
  84   # POST  /ostatus_subscribe
  85   #
  86   # step 1.
  87   # checks login\password and displays step 2 form of MFA if need.
  88   #
  89   def do_follow(conn, %{"authorization" => %{"name" => _, "password" => _, "id" => id}}) do
  90     with {_, %User{} = followee} <- {:fetch_user, User.get_cached_by_id(id)},
  91          {_, {:ok, user}, _} <- {:auth, Authenticator.get_user(conn), followee},
  92          {_, _, _, false} <- {:mfa_required, followee, user, MFA.require?(user)},
  93          {:ok, _, _, _} <- CommonAPI.follow(user, followee) do
  94       redirect(conn, to: "/users/#{followee.id}")
  95     else
  96       error ->
  97         handle_follow_error(conn, error)
  98     end
  99   end
 100
 101   # POST  /ostatus_subscribe
 102   #
 103   # step 2
 104   # checks TOTP code. otherwise displays form with errors
 105   #
 106   def do_follow(conn, %{"mfa" => %{"code" => code, "token" => token, "id" => id}}) do
 107     with {_, %User{} = followee} <- {:fetch_user, User.get_cached_by_id(id)},
 108          {_, _, {:ok, %{user: user}}} <- {:mfa_token, followee, MFA.Token.validate(token)},
 109          {_, _, _, {:ok, _}} <-
 110            {:verify_mfa_code, followee, token, TOTPAuthenticator.verify(code, user)},
 111          {:ok, _, _, _} <- CommonAPI.follow(user, followee) do
 112       redirect(conn, to: "/users/#{followee.id}")
 113     else
 114       error ->
 115         handle_follow_error(conn, error)
 116     end
 117   end
 118
 119   def do_follow(%{assigns: %{user: nil}} = conn, _) do
 120     Logger.debug("Insufficient permissions: follow | write:follows.")
 121     render(conn, "followed.html", %{error: "Insufficient permissions: follow | write:follows."})
 122   end
 123
 124   defp handle_follow_error(conn, {:mfa_token, followee, _} = _) do
 125     render(conn, "follow_login.html", %{error: "Wrong username or password", followee: followee})
 126   end
 127
 128   defp handle_follow_error(conn, {:verify_mfa_code, followee, token, _} = _) do
 129     render(conn, "follow_mfa.html", %{
 130       error: "Wrong authentication code",
 131       followee: followee,
 132       mfa_token: token
 133     })
 134   end
 135
 136   defp handle_follow_error(conn, {:mfa_required, followee, user, _} = _) do
 137     {:ok, %{token: token}} = MFA.Token.create(user)
 138     render(conn, "follow_mfa.html", %{followee: followee, mfa_token: token, error: false})
 139   end
 140
 141   defp handle_follow_error(conn, {:auth, _, followee} = _) do
 142     render(conn, "follow_login.html", %{error: "Wrong username or password", followee: followee})
 143   end
 144
 145   defp handle_follow_error(conn, {:fetch_user, error} = _) do
 146     Logger.debug("Remote follow failed with error #{inspect(error)}")
 147     render(conn, "followed.html", %{error: "Could not find user"})
 148   end
 149
 150   defp handle_follow_error(conn, {:error, "Could not follow user:" <> _} = _) do
 151     render(conn, "followed.html", %{error: "Error following account"})
 152   end
 153
 154   defp handle_follow_error(conn, error) do
 155     Logger.debug("Remote follow failed with error #{inspect(error)}")
 156     render(conn, "followed.html", %{error: "Something went wrong."})
 157   end
 158 end