akkoma/lib/pleroma/web/websub/websub.ex
2017-04-29 20:08:45 +02:00

185 lines
6.1 KiB
Elixir

defmodule Pleroma.Web.Websub do
alias Pleroma.Repo
alias Pleroma.Web.Websub.{WebsubServerSubscription, WebsubClientSubscription}
alias Pleroma.Web.OStatus.FeedRepresenter
alias Pleroma.Web.{XML, Endpoint, OStatus}
alias Pleroma.Web.Router.Helpers
require Logger
import Ecto.Query
def verify(subscription, getter \\ &HTTPoison.get/3 ) do
challenge = Base.encode16(:crypto.strong_rand_bytes(8))
lease_seconds = NaiveDateTime.diff(subscription.valid_until, subscription.updated_at) |> to_string
params = %{
"hub.challenge": challenge,
"hub.lease_seconds": lease_seconds,
"hub.topic": subscription.topic,
"hub.mode": "subscribe"
}
url = hd(String.split(subscription.callback, "?"))
query = URI.parse(subscription.callback).query || ""
params = Map.merge(params, URI.decode_query(query))
with {:ok, response} <- getter.(url, [], [params: params]),
^challenge <- response.body
do
changeset = Ecto.Changeset.change(subscription, %{state: "active"})
Repo.update(changeset)
else _e ->
changeset = Ecto.Changeset.change(subscription, %{state: "rejected"})
{:ok, subscription } = Repo.update(changeset)
{:error, subscription}
end
end
def publish(topic, user, activity) do
query = from sub in WebsubServerSubscription,
where: sub.topic == ^topic and sub.state == "active"
subscriptions = Repo.all(query)
Enum.each(subscriptions, fn(sub) ->
response = FeedRepresenter.to_simple_form(user, [activity], [user])
|> :xmerl.export_simple(:xmerl_xml)
signature = sign(sub.secret, response)
HTTPoison.post(sub.callback, response, [
{"Content-Type", "application/atom+xml"},
{"X-Hub-Signature", "sha1=#{signature}"}
])
end)
end
def sign(secret, doc) do
:crypto.hmac(:sha, secret, doc) |> Base.encode16
end
def incoming_subscription_request(user, %{"hub.mode" => "subscribe"} = params) do
with {:ok, topic} <- valid_topic(params, user),
{:ok, lease_time} <- lease_time(params),
secret <- params["hub.secret"],
callback <- params["hub.callback"]
do
subscription = get_subscription(topic, callback)
data = %{
state: subscription.state || "requested",
topic: topic,
secret: secret,
callback: callback
}
change = Ecto.Changeset.change(subscription, data)
websub = Repo.insert_or_update!(change)
change = Ecto.Changeset.change(websub, %{valid_until: NaiveDateTime.add(websub.updated_at, lease_time)})
websub = Repo.update!(change)
Pleroma.Web.Federator.enqueue(:verify_websub, websub)
{:ok, websub}
else {:error, reason} ->
{:error, reason}
end
end
defp get_subscription(topic, callback) do
Repo.get_by(WebsubServerSubscription, topic: topic, callback: callback) || %WebsubServerSubscription{}
end
defp lease_time(%{"hub.lease_seconds" => lease_seconds}) do
{:ok, String.to_integer(lease_seconds)}
end
defp lease_time(_) do
{:ok, 60 * 60 * 24 * 3} # three days
end
defp valid_topic(%{"hub.topic" => topic}, user) do
if topic == OStatus.feed_path(user) do
{:ok, topic}
else
{:error, "Wrong topic requested, expected #{OStatus.feed_path(user)}, got #{topic}"}
end
end
def subscribe(subscriber, subscribed, requester \\ &request_subscription/1) do
topic = subscribed.info["topic"]
# FIXME: Race condition, use transactions
{:ok, subscription} = with subscription when not is_nil(subscription) <- Repo.get_by(WebsubClientSubscription, topic: topic) do
subscribers = [subscriber.ap_id, subscription.subscribers] |> Enum.uniq
change = Ecto.Changeset.change(subscription, %{subscribers: subscribers})
Repo.update(change)
else _e ->
subscription = %WebsubClientSubscription{
topic: topic,
hub: subscribed.info["hub"],
subscribers: [subscriber.ap_id],
state: "requested",
secret: :crypto.strong_rand_bytes(8) |> Base.url_encode64,
user: subscribed
}
Repo.insert(subscription)
end
requester.(subscription)
end
def gather_feed_data(topic, getter \\ &HTTPoison.get/1) do
with {:ok, response} <- getter.(topic),
status_code when status_code in 200..299 <- response.status_code,
body <- response.body,
doc <- XML.parse_document(body),
uri when not is_nil(uri) <- XML.string_from_xpath("/feed/author[1]/uri", doc),
hub when not is_nil(hub) <- XML.string_from_xpath(~S{/feed/link[@rel="hub"]/@href}, doc) do
name = XML.string_from_xpath("/feed/author[1]/name", doc)
preferredUsername = XML.string_from_xpath("/feed/author[1]/poco:preferredUsername", doc)
displayName = XML.string_from_xpath("/feed/author[1]/poco:displayName", doc)
{:ok, %{
uri: uri,
hub: hub,
nickname: preferredUsername || name,
name: displayName || name,
host: URI.parse(uri).host
}}
else e ->
{:error, e}
end
end
def request_subscription(websub, poster \\ &HTTPoison.post/3, timeout \\ 10_000) do
data = [
"hub.mode": "subscribe",
"hub.topic": websub.topic,
"hub.secret": websub.secret,
"hub.callback": Helpers.websub_url(Endpoint, :websub_subscription_confirmation, websub.id)
]
# This checks once a second if we are confirmed yet
websub_checker = fn ->
helper = fn (helper) ->
:timer.sleep(1000)
websub = Repo.get_by(WebsubClientSubscription, id: websub.id, state: "accepted")
if websub, do: websub, else: helper.(helper)
end
helper.(helper)
end
task = Task.async(websub_checker)
with {:ok, %{status_code: 202}} <- poster.(websub.hub, {:form, data}, ["Content-type": "application/x-www-form-urlencoded"]),
{:ok, websub} <- Task.yield(task, timeout) do
{:ok, websub}
else e ->
Task.shutdown(task)
change = Ecto.Changeset.change(websub, %{state: "rejected"})
{:ok, websub} = Repo.update(change)
Logger.debug("Couldn't confirm subscription: #{inspect(websub)}")
Logger.debug("error: #{inspect(e)}")
{:error, websub}
end
end
end