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       |> to_string
  45
  46       signature = sign(sub.secret, response)
  47       HTTPoison.post(sub.callback, response, [
  48             {"Content-Type", "application/atom+xml"},
  49             {"X-Hub-Signature", "sha1=#{signature}"}
  50           ])
  51     end)
  52   end
  53
  54   def sign(secret, doc) do
  55     :crypto.hmac(:sha, secret, to_string(doc)) |> Base.encode16
  56   end
  57
  58   def incoming_subscription_request(user, %{"hub.mode" => "subscribe"} = params) do
  59     with {:ok, topic} <- valid_topic(params, user),
  60          {:ok, lease_time} <- lease_time(params),
  61          secret <- params["hub.secret"],
  62          callback <- params["hub.callback"]
  63     do
  64       subscription = get_subscription(topic, callback)
  65       data = %{
  66         state: subscription.state || "requested",
  67         topic: topic,
  68         secret: secret,
  69         callback: callback
  70       }
  71
  72       change = Ecto.Changeset.change(subscription, data)
  73       websub = Repo.insert_or_update!(change)
  74
  75       change = Ecto.Changeset.change(websub, %{valid_until: NaiveDateTime.add(websub.updated_at, lease_time)})
  76       websub = Repo.update!(change)
  77
  78       Pleroma.Web.Federator.enqueue(:verify_websub, websub)
  79
  80       {:ok, websub}
  81     else {:error, reason} ->
  82       Logger.debug("Couldn't create subscription.")
  83       Logger.debug(inspect(reason))
  84
  85       {:error, reason}
  86     end
  87   end
  88
  89   defp get_subscription(topic, callback) do
  90     Repo.get_by(WebsubServerSubscription, topic: topic, callback: callback) || %WebsubServerSubscription{}
  91   end
  92
  93   # Temp hack for mastodon.
  94   defp lease_time(%{"hub.lease_seconds" => ""}) do
  95     {:ok, 60 * 60 * 24 * 3} # three days
  96   end
  97
  98   defp lease_time(%{"hub.lease_seconds" => lease_seconds}) do
  99     {:ok, String.to_integer(lease_seconds)}
 100   end
 101
 102   defp lease_time(_) do
 103     {:ok, 60 * 60 * 24 * 3} # three days
 104   end
 105
 106   defp valid_topic(%{"hub.topic" => topic}, user) do
 107     if topic == OStatus.feed_path(user) do
 108       {:ok, OStatus.feed_path(user)}
 109     else
 110       {:error, "Wrong topic requested, expected #{OStatus.feed_path(user)}, got #{topic}"}
 111     end
 112   end
 113
 114   def subscribe(subscriber, subscribed, requester \\ &request_subscription/1) do
 115     topic = subscribed.info["topic"]
 116     # FIXME: Race condition, use transactions
 117     {:ok, subscription} = with subscription when not is_nil(subscription) <- Repo.get_by(WebsubClientSubscription, topic: topic) do
 118       subscribers = [subscriber.ap_id, subscription.subscribers] |> Enum.uniq
 119       change = Ecto.Changeset.change(subscription, %{subscribers: subscribers})
 120       Repo.update(change)
 121     else _e ->
 122       subscription = %WebsubClientSubscription{
 123         topic: topic,
 124         hub: subscribed.info["hub"],
 125         subscribers: [subscriber.ap_id],
 126         state: "requested",
 127         secret: :crypto.strong_rand_bytes(8) |> Base.url_encode64,
 128         user: subscribed
 129       }
 130       Repo.insert(subscription)
 131     end
 132     requester.(subscription)
 133   end
 134
 135   def gather_feed_data(topic, getter \\ &HTTPoison.get/1) do
 136     with {:ok, response} <- getter.(topic),
 137          status_code when status_code in 200..299 <- response.status_code,
 138          body <- response.body,
 139          doc <- XML.parse_document(body),
 140          uri when not is_nil(uri) <- XML.string_from_xpath("/feed/author[1]/uri", doc),
 141          hub when not is_nil(hub) <- XML.string_from_xpath(~S{/feed/link[@rel="hub"]/@href}, doc) do
 142
 143       name = XML.string_from_xpath("/feed/author[1]/name", doc)
 144       preferredUsername = XML.string_from_xpath("/feed/author[1]/poco:preferredUsername", doc)
 145       displayName = XML.string_from_xpath("/feed/author[1]/poco:displayName", doc)
 146       avatar = OStatus.make_avatar_object(doc)
 147
 148       {:ok, %{
 149         uri: uri,
 150         hub: hub,
 151         nickname: preferredUsername || name,
 152         name: displayName || name,
 153         host: URI.parse(uri).host,
 154         avatar: avatar
 155       }}
 156     else e ->
 157       {:error, e}
 158     end
 159   end
 160
 161   def request_subscription(websub, poster \\ &HTTPoison.post/3, timeout \\ 10_000) do
 162     data = [
 163       "hub.mode": "subscribe",
 164       "hub.topic": websub.topic,
 165       "hub.secret": websub.secret,
 166       "hub.callback": Helpers.websub_url(Endpoint, :websub_subscription_confirmation, websub.id)
 167     ]
 168
 169     # This checks once a second if we are confirmed yet
 170     websub_checker = fn ->
 171       helper = fn (helper) ->
 172         :timer.sleep(1000)
 173         websub = Repo.get_by(WebsubClientSubscription, id: websub.id, state: "accepted")
 174         if websub, do: websub, else: helper.(helper)
 175       end
 176       helper.(helper)
 177     end
 178
 179     task = Task.async(websub_checker)
 180
 181     with {:ok, %{status_code: 202}} <- poster.(websub.hub, {:form, data}, ["Content-type": "application/x-www-form-urlencoded"]),
 182          {:ok, websub} <- Task.yield(task, timeout) do
 183       {:ok, websub}
 184     else e ->
 185       Task.shutdown(task)
 186
 187       change = Ecto.Changeset.change(websub, %{state: "rejected"})
 188       {:ok, websub} = Repo.update(change)
 189
 190       Logger.debug("Couldn't confirm subscription: #{inspect(websub)}")
 191       Logger.debug("error: #{inspect(e)}")
 192
 193       {:error, websub}
 194     end
 195   end
 196 end