git.squeep.com Git - akkoma/blob - lib/pleroma/web/websub/websub.ex

   1 defmodule Pleroma.Web.Websub do
   2   alias Pleroma.Repo
   3   alias Pleroma.Web.Websub.{WebsubServerSubscription, WebsubClientSubscription}
   4   alias Pleroma.Web.OStatus.FeedRepresenter
   5   alias Pleroma.Web.{XML, Endpoint, OStatus}
   6   alias Pleroma.Web.Router.Helpers
   7   require Logger
   8
   9   import Ecto.Query
  10
  11   def verify(subscription, getter \\ &HTTPoison.get/3 ) do
  12     challenge = Base.encode16(:crypto.strong_rand_bytes(8))
  13     lease_seconds = NaiveDateTime.diff(subscription.valid_until, subscription.updated_at) |> to_string
  14
  15     params = %{
  16       "hub.challenge": challenge,
  17       "hub.lease_seconds": lease_seconds,
  18       "hub.topic": subscription.topic,
  19       "hub.mode": "subscribe"
  20     }
  21
  22     url = hd(String.split(subscription.callback, "?"))
  23     query = URI.parse(subscription.callback).query || ""
  24     params = Map.merge(params, URI.decode_query(query))
  25     with {:ok, response} <- getter.(url, [], [params: params]),
  26          ^challenge <- response.body
  27     do
  28       changeset = Ecto.Changeset.change(subscription, %{state: "active"})
  29       Repo.update(changeset)
  30     else _e ->
  31       changeset = Ecto.Changeset.change(subscription, %{state: "rejected"})
  32       {:ok, subscription } = Repo.update(changeset)
  33       {:error, subscription}
  34     end
  35   end
  36
  37   def publish(topic, user, activity) do
  38     query = from sub in WebsubServerSubscription,
  39     where: sub.topic == ^topic and sub.state == "active"
  40     subscriptions = Repo.all(query)
  41     Enum.each(subscriptions, fn(sub) ->
  42       response = FeedRepresenter.to_simple_form(user, [activity], [user])
  43       |> :xmerl.export_simple(:xmerl_xml)
  44
  45       signature = sign(sub.secret, response)
  46       HTTPoison.post(sub.callback, response, [
  47             {"Content-Type", "application/atom+xml"},
  48             {"X-Hub-Signature", "sha1=#{signature}"}
  49           ])
  50     end)
  51   end
  52
  53   def sign(secret, doc) do
  54     :crypto.hmac(:sha, secret, doc) |> Base.encode16
  55   end
  56
  57   def incoming_subscription_request(user, %{"hub.mode" => "subscribe"} = params) do
  58     with {:ok, topic} <- valid_topic(params, user),
  59          {:ok, lease_time} <- lease_time(params),
  60          secret <- params["hub.secret"],
  61          callback <- params["hub.callback"]
  62     do
  63       subscription = get_subscription(topic, callback)
  64       data = %{
  65         state: subscription.state || "requested",
  66         topic: topic,
  67         secret: secret,
  68         callback: callback
  69       }
  70
  71       change = Ecto.Changeset.change(subscription, data)
  72       websub = Repo.insert_or_update!(change)
  73
  74       change = Ecto.Changeset.change(websub, %{valid_until: NaiveDateTime.add(websub.updated_at, lease_time)})
  75       websub = Repo.update!(change)
  76
  77       Pleroma.Web.Federator.enqueue(:verify_websub, websub)
  78
  79       {:ok, websub}
  80     else {:error, reason} ->
  81       {:error, reason}
  82     end
  83   end
  84
  85   defp get_subscription(topic, callback) do
  86     Repo.get_by(WebsubServerSubscription, topic: topic, callback: callback) || %WebsubServerSubscription{}
  87   end
  88
  89   defp lease_time(%{"hub.lease_seconds" => lease_seconds}) do
  90     {:ok, String.to_integer(lease_seconds)}
  91   end
  92
  93   defp lease_time(_) do
  94     {:ok, 60 * 60 * 24 * 3} # three days
  95   end
  96
  97   defp valid_topic(%{"hub.topic" => topic}, user) do
  98     if topic == OStatus.feed_path(user) do
  99       {:ok, topic}
 100     else
 101       {:error, "Wrong topic requested, expected #{OStatus.feed_path(user)}, got #{topic}"}
 102     end
 103   end
 104
 105   def subscribe(user, topic, requester \\ &request_subscription/1) do
 106     # FIXME: Race condition, use transactions
 107     {:ok, subscription} = with subscription when not is_nil(subscription) <- Repo.get_by(WebsubClientSubscription, topic: topic) do
 108       subscribers = [user.ap_id, subscription.subcribers] |> Enum.uniq
 109       change = Ecto.Changeset.change(subscription, %{subscribers: subscribers})
 110       Repo.update(change)
 111     else _e ->
 112       subscription = %WebsubClientSubscription{
 113         topic: topic,
 114         subscribers: [user.ap_id],
 115         state: "requested",
 116         secret: :crypto.strong_rand_bytes(8) |> Base.url_encode64,
 117         user: user
 118       }
 119       Repo.insert(subscription)
 120     end
 121     requester.(subscription)
 122   end
 123
 124   def gather_feed_data(topic, getter \\ &HTTPoison.get/1) do
 125     with {:ok, response} <- getter.(topic),
 126          status_code when status_code in 200..299 <- response.status_code,
 127          body <- response.body,
 128          doc <- XML.parse_document(body),
 129          uri when not is_nil(uri) <- XML.string_from_xpath("/feed/author[1]/uri", doc),
 130          hub when not is_nil(hub) <- XML.string_from_xpath(~S{/feed/link[@rel="hub"]/@href}, doc) do
 131
 132       name = XML.string_from_xpath("/feed/author[1]/name", doc)
 133       preferredUsername = XML.string_from_xpath("/feed/author[1]/poco:preferredUsername", doc)
 134       displayName = XML.string_from_xpath("/feed/author[1]/poco:displayName", doc)
 135
 136       {:ok, %{
 137         uri: uri,
 138         hub: hub,
 139         nickname: preferredUsername || name,
 140         name: displayName || name
 141       }}
 142     else e ->
 143       {:error, e}
 144     end
 145   end
 146
 147   def request_subscription(websub, poster \\ &HTTPoison.post/3, timeout \\ 10_000) do
 148     data = [
 149       "hub.mode": "subscribe",
 150       "hub.topic": websub.topic,
 151       "hub.secret": websub.secret,
 152       "hub.callback": Helpers.websub_url(Endpoint, :websub_subscription_confirmation, websub.id)
 153     ]
 154
 155     # This checks once a second if we are confirmed yet
 156     websub_checker = fn ->
 157       helper = fn (helper) ->
 158         :timer.sleep(1000)
 159         websub = Repo.get_by(WebsubClientSubscription, id: websub.id, state: "accepted")
 160         if websub, do: websub, else: helper.(helper)
 161       end
 162       helper.(helper)
 163     end
 164
 165     task = Task.async(websub_checker)
 166
 167     with {:ok, %{status_code: 202}} <- poster.(websub.hub, {:form, data}, ["Content-type": "application/x-www-form-urlencoded"]),
 168          {:ok, websub} <- Task.yield(task, timeout) do
 169       {:ok, websub}
 170     else e ->
 171       Task.shutdown(task)
 172
 173       change = Ecto.Changeset.change(websub, %{state: "rejected"})
 174       {:ok, websub} = Repo.update(change)
 175
 176       Logger.debug("Couldn't confirm subscription: #{inspect(websub)}")
 177       Logger.debug("error: #{inspect(e)}")
 178
 179       {:error, websub}
 180     end
 181   end
 182 end