Push forwarding

lib/tusker_push/apns.ex

@@ -1,32 +1,87 @@
 defmodule TuskerPush.Apns do
   alias TuskerPush.Registration
 
+  require Logger
+
   @spec send(Registration.t(), Map.t()) :: :ok | {:error, term()}
   def send(registration, payload) do
-    req =
-      Finch.build(:post, %URI{
-        scheme: "https",
-        authority: host(registration.apns_environment),
-        host: host(registration.apns_environment),
-        port: 443,
-        path: "/3/device/#{registration.apns_device_token}"
-      })
-
-    headers = [
-      {"authorization", "bearer #{TuskerPush.Apns.Token.current()}"},
-      {"apns-push-type", "alert"},
-      {"apns-bundle-id", Application.fetch_env!(:tusker_push, :apns)[:bundle_id]}
-    ]
-
     with {:ok, body} <- Jason.encode(payload, pretty_print: false),
-         {:ok, resp} <- Finch.request(req, TuskerPush.Finch, headers, body) do
+         req <- make_request(registration, body),
-      nil
+         {:ok, resp} <- Finch.request(req, TuskerPush.Finch) do
+      handle_response(resp, registration.apns_environment)
     else
       {:error, reason} ->
         {:error, reason}
     end
   end
 
+  @spec make_request(Registration.t(), binary()) :: Finch.Request.t()
+  defp make_request(registration, body) do
+    bundle_id = Application.fetch_env!(:tusker_push, :apns)[:bundle_id]
+
+    headers = [
+      {"authorization", "bearer #{TuskerPush.Apns.Token.current()}"},
+      {"apns-push-type", "alert"},
+      {"apns-bundle-id", bundle_id},
+      {"apns-topic", bundle_id},
+      {"apns-expiration",
+       DateTime.utc_now() |> DateTime.add(1, :day) |> DateTime.to_unix() |> Integer.to_string()}
+    ]
+
+    Finch.build(
+      :post,
+      "https://#{host(registration.apns_environment)}/3/device/#{registration.apns_device_token}",
+      headers,
+      body
+    )
+  end
+
+  @spec handle_response(Finch.Response.t(), :development | :production) :: :ok | {:error, term()}
+
+  defp handle_response(resp, env) do
+    maybe_log_unique_id(resp, env)
+
+    if resp.status in 200..299 do
+      :ok
+    else
+      info =
+        case Jason.decode(resp.body) do
+          {:ok, data} ->
+            inspect(data)
+
+          {:error, _} ->
+            resp.body
+        end
+
+      Logger.error("Received #{resp.status} with #{info}")
+
+      {:error, "unexpected status #{resp.status}"}
+    end
+  end
+
+  @spec maybe_log_unique_id(Finch.Response.t(), :development | :production) :: :ok
+
+  defp maybe_log_unique_id(resp, :development) do
+    resp.headers
+    |> Enum.find(fn
+      {"apns-unique-id", _} -> true
+      _ -> false
+    end)
+    |> case do
+      {_, id} ->
+        Logger.debug("APNS unique id: #{id}")
+
+      _ ->
+        nil
+    end
+
+    :ok
+  end
+
+  defp maybe_log_unique_id(_resp, :production), do: :ok
+
+  @spec host(:development | :production) :: String.t()
+
   def host(:development) do
     "api.sandbox.push.apple.com"
   end

lib/tusker_push/apns/token.ex

@@ -1,26 +1,27 @@
 defmodule TuskerPush.Apns.Token do
   use GenServer
 
+  require Logger
+
   def start_link(_) do
     GenServer.start_link(__MODULE__, nil, name: __MODULE__)
   end
 
-  def refresh(expected_token) do
-    GenServer.call(__MODULE__, {:refresh, expected_token})
-  end
-
   def current do
     GenServer.call(__MODULE__, :current)
   end
 
   @impl true
   def init(_) do
+    Logger.debug("Apns.Token initialized, scheduling update")
     Process.send_after(self(), :refresh, 1000 * 60 * 45)
     {:ok, generate_token()}
   end
 
   @impl true
   def handle_info(:refresh, _old_token) do
+    Logger.debug("Apns.Token regenerated")
+    Process.send_after(self(), :refresh, 1000 * 60 * 45)
     {:noreply, generate_token()}
   end
 
@@ -29,17 +30,6 @@ defmodule TuskerPush.Apns.Token do
     {:reply, token, token}
   end
 
-  @impl true
-  def handle_call({:refresh, expected_token}, _from, token) when expected_token == token do
-    new_token = generate_token()
-    {:reply, new_token, new_token}
-  end
-
-  @impl true
-  def handle_call({:refresh, _expected_token}, _from, token) do
-    {:reply, token, token}
-  end
-
   defp generate_token do
     # can't use Joken because it always inserts "typ": "JWT" which APNS doesn't like
 

lib/tusker_push/forwarder.ex

@@ -14,7 +14,7 @@ defmodule TuskerPush.Forwarder do
       "reg_id" => registration.id,
       "data" => Base.encode64(body),
       "salt" => salt,
-      "key" => key
+      "pk" => key
     }
 
     Apns.send(registration, payload)

lib/tusker_push_web/controllers/push_controller.ex

@@ -1,4 +1,5 @@
 defmodule TuskerPushWeb.PushController do
+  alias TuskerPush.Forwarder
   use TuskerPushWeb, :controller
 
   require Logger
@@ -7,8 +8,11 @@ defmodule TuskerPushWeb.PushController do
     with {:registration, registration} when not is_nil(registration) <-
            {:registration, TuskerPush.get_registration(id)},
          :ok <- TuskerPush.check_registration_expired(registration),
-         {:ok, body, conn} <- read_body(conn) do
+         {:encoding, ["aesgcm"]} <- {:encoding, get_req_header(conn, "content-encoding")},
-      IO.inspect(body |> byte_size())
+         {:body, {:ok, body, conn}} <- {:body, read_body(conn)},
+         {:salt, salt} when not is_nil(salt) <- get_salt(conn),
+         {:key, key} when not is_nil(key) <- get_key(conn),
+         {:forward, :ok} <- {:forward, Forwarder.forward(registration, body, salt, key)} do
       send_resp(conn, 200, "ok")
     else
       {:registration, nil} ->
@@ -16,18 +20,63 @@ defmodule TuskerPushWeb.PushController do
 
       {:expired, registration} ->
         TuskerPush.unregister(registration)
-
         send_resp(conn, 400, "unregistered")
 
-      {:more, _, conn} ->
+      {:encoding, encoding} ->
+        Logger.warning("Unexpected encoding: #{inspect(encoding)}")
+        send_resp(conn, 400, "bad encoding")
+
+      {:body, {:more, _, conn}} ->
         Logger.error("Didn't finish reading")
-
         send_resp(conn, 500, "failed to read body")
 
-      {:error, reason} ->
+      {:body, {:error, reason}} ->
         Logger.error("Reading body: #{inspect(reason)}")
-
         send_resp(conn, 500, "failed to read body")
+
+      {:salt, nil} ->
+        Logger.warning("Missing salt")
+        send_resp(conn, 400, "missing salt")
+
+      {:key, nil} ->
+        Logger.warning("Missing key")
+        send_resp(conn, 400, "missing key")
+
+      {:forward, {:error, reason}} ->
+        Logger.error("Sending notification: #{inspect(reason)}")
+        send_resp(conn, 500, "failed to send")
+    end
+  end
+
+  defp get_salt(conn) do
+    conn
+    |> get_req_header("encryption")
+    |> case do
+      ["salt=" <> salt] ->
+        {:salt, salt}
+
+      _ ->
+        {:salt, nil}
+    end
+  end
+
+  defp get_key(conn) do
+    conn
+    |> get_req_header("crypto-key")
+    |> case do
+      [value] ->
+        dh =
+          value
+          |> String.split(";")
+          |> Enum.find_value(fn
+            "dh=" <> val -> val
+            _ -> false
+          end)
+
+        {:key, dh}
+
+      _ ->
+        {:key, nil}
     end
   end
 end