1 files changed, 102 insertions, 0 deletions
diff --git a/lib/pleroma/web/websub/websub.ex b/lib/pleroma/web/websub/websub.ex
new file mode 100644
index 000000000..cc66b52dd
--- /dev/null
+++ b/lib/pleroma/web/websub/websub.ex
@@ -0,0 +1,102 @@
+defmodule Pleroma.Web.Websub do
+  alias Pleroma.Repo
+  alias Pleroma.Web.Websub.WebsubServerSubscription
+  alias Pleroma.Web.OStatus.FeedRepresenter
+  alias Pleroma.Web.OStatus
+
+  import Ecto.Query
+
+  @websub_verifier Application.get_env(:pleroma, :websub_verifier)
+
+  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 = :crypto.hmac(:sha, sub.secret, response) |> Base.encode16
+
+      HTTPoison.post(sub.callback, response, [
+            {"Content-Type", "application/atom+xml"},
+            {"X-Hub-Signature", "sha1=#{signature}"}
+          ])
+    end)
+  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)
+
+      # Just spawn that for now, maybe pool later.
+      spawn(fn -> @websub_verifier.verify(websub) end)
+
+      {: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
+end