APNS tokens

lib/tusker_push/apns.ex

@@ -0,0 +1,37 @@
+defmodule TuskerPush.Apns do
+  alias TuskerPush.Registration
+
+  @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
+      nil
+    else
+      {:error, reason} ->
+        {:error, reason}
+    end
+  end
+
+  def host(:development) do
+    "api.sandbox.push.apple.com"
+  end
+
+  def host(:production) do
+    "api.push.apple.com"
+  end
+end

lib/tusker_push/apns/token.ex

@@ -0,0 +1,67 @@
+defmodule TuskerPush.Apns.Token do
+  use GenServer
+
+  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
+    Process.send_after(self(), :refresh, 1000 * 60 * 45)
+    {:ok, generate_token()}
+  end
+
+  @impl true
+  def handle_info(:refresh, _old_token) do
+    {:noreply, generate_token()}
+  end
+
+  @impl true
+  def handle_call(:current, _from, 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
+
+    config = Application.fetch_env!(:tusker_push, :apns)
+
+    jwk = JOSE.JWK.from_pem(config[:key_pem])
+
+    jws =
+      JOSE.JWS.from_map(%{
+        "kid" => config[:key_id],
+        "alg" => "ES256"
+      })
+
+    claims = %{
+      "iss" => config[:team_id],
+      "iat" => DateTime.utc_now() |> DateTime.to_unix()
+    }
+
+    {_, result} =
+      JOSE.JWT.sign(jwk, jws, claims)
+      |> JOSE.JWS.compact()
+
+    result
+  end
+end

lib/tusker_push/application.ex

@@ -14,6 +14,13 @@ defmodule TuskerPush.Application do
       {Phoenix.PubSub, name: TuskerPush.PubSub},
       # Start a worker by calling: TuskerPush.Worker.start_link(arg)
       # {TuskerPush.Worker, arg},
+      {Finch,
+       name: TuskerPush.Finch,
+       pools: %{
+         ("https://" <> TuskerPush.Apns.host(:development)) => [protocols: [:http2], count: 1],
+         ("https://" <> TuskerPush.Apns.host(:production)) => [protocols: [:http2], count: 1]
+       }},
+      TuskerPush.Apns.Token,
       # Start to serve requests, typically the last entry
       TuskerPushWeb.Endpoint
     ]

lib/tusker_push/forwarder.ex

@@ -0,0 +1,22 @@
+defmodule TuskerPush.Forwarder do
+  alias TuskerPush.Apns
+  alias TuskerPush.Registration
+
+  @spec forward(Registration.t(), binary(), String.t(), String.t()) :: :ok | {:error, term()}
+  def forward(registration, body, salt, key) do
+    payload = %{
+      "aps" => %{
+        "alert" => %{
+          "loc-key" => "apns_enc"
+        },
+        "mutable-content" => 1
+      },
+      "reg_id" => registration.id,
+      "data" => Base.encode64(body),
+      "salt" => salt,
+      "key" => key
+    }
+
+    Apns.send(registration, payload)
+  end
+end

lib/tusker_push/registration.ex

@@ -18,6 +18,7 @@ defmodule TuskerPush.Registration do
     field :storekit_original_transaction_id, :string
 
     field :apns_environment, Ecto.Enum, values: [:production, :development]
+    # hex-encoded
     field :apns_device_token, :string
 
     timestamps()

mix.exs

@@ -41,7 +41,9 @@ defmodule TuskerPush.MixProject do
       {:jason, "~> 1.2"},
       {:dns_cluster, "~> 0.1.1"},
       {:bandit, "~> 1.2"},
-      {:dialyxir, "~> 1.4", only: [:dev, :test], runtime: false}
+      {:dialyxir, "~> 1.4", only: [:dev, :test], runtime: false},
+      {:finch, "~> 0.18"},
+      {:jose, "~> 1.11"}
     ]
   end
 

mix.lock

@@ -8,9 +8,15 @@
   "ecto": {:hex, :ecto, "3.11.2", "e1d26be989db350a633667c5cda9c3d115ae779b66da567c68c80cfb26a8c9ee", [:mix], [{:decimal, "~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "3c38bca2c6f8d8023f2145326cc8a80100c3ffe4dcbd9842ff867f7fc6156c65"},
   "ecto_sql": {:hex, :ecto_sql, "3.11.1", "e9abf28ae27ef3916b43545f9578b4750956ccea444853606472089e7d169470", [:mix], [{:db_connection, "~> 2.4.1 or ~> 2.5", [hex: :db_connection, repo: "hexpm", optional: false]}, {:ecto, "~> 3.11.0", [hex: :ecto, repo: "hexpm", optional: false]}, {:myxql, "~> 0.6.0", [hex: :myxql, repo: "hexpm", optional: true]}, {:postgrex, "~> 0.16.0 or ~> 0.17.0 or ~> 1.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:tds, "~> 2.1.1 or ~> 2.2", [hex: :tds, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4.0 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "ce14063ab3514424276e7e360108ad6c2308f6d88164a076aac8a387e1fea634"},
   "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
+  "finch": {:hex, :finch, "0.18.0", "944ac7d34d0bd2ac8998f79f7a811b21d87d911e77a786bc5810adb75632ada4", [:mix], [{:castore, "~> 0.1 or ~> 1.0", [hex: :castore, repo: "hexpm", optional: false]}, {:mime, "~> 1.0 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}, {:mint, "~> 1.3", [hex: :mint, repo: "hexpm", optional: false]}, {:nimble_options, "~> 0.4 or ~> 1.0", [hex: :nimble_options, repo: "hexpm", optional: false]}, {:nimble_pool, "~> 0.2.6 or ~> 1.0", [hex: :nimble_pool, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "69f5045b042e531e53edc2574f15e25e735b522c37e2ddb766e15b979e03aa65"},
   "hpax": {:hex, :hpax, "0.1.2", "09a75600d9d8bbd064cdd741f21fc06fc1f4cf3d0fcc335e5aa19be1a7235c84", [:mix], [], "hexpm", "2c87843d5a23f5f16748ebe77969880e29809580efdaccd615cd3bed628a8c13"},
   "jason": {:hex, :jason, "1.4.1", "af1504e35f629ddcdd6addb3513c3853991f694921b1b9368b0bd32beb9f1b63", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "fbb01ecdfd565b56261302f7e1fcc27c4fb8f32d56eab74db621fc154604a7a1"},
+  "joken": {:hex, :joken, "2.6.0", "b9dd9b6d52e3e6fcb6c65e151ad38bf4bc286382b5b6f97079c47ade6b1bcc6a", [:mix], [{:jose, "~> 1.11.5", [hex: :jose, repo: "hexpm", optional: false]}], "hexpm", "5a95b05a71cd0b54abd35378aeb1d487a23a52c324fa7efdffc512b655b5aaa7"},
+  "jose": {:hex, :jose, "1.11.6", "613fda82552128aa6fb804682e3a616f4bc15565a048dabd05b1ebd5827ed965", [:mix, :rebar3], [], "hexpm", "6275cb75504f9c1e60eeacb771adfeee4905a9e182103aa59b53fed651ff9738"},
   "mime": {:hex, :mime, "2.0.5", "dc34c8efd439abe6ae0343edbb8556f4d63f178594894720607772a041b04b02", [:mix], [], "hexpm", "da0d64a365c45bc9935cc5c8a7fc5e49a0e0f9932a761c55d6c52b142780a05c"},
+  "mint": {:hex, :mint, "1.5.2", "4805e059f96028948870d23d7783613b7e6b0e2fb4e98d720383852a760067fd", [:mix], [{:castore, "~> 0.1.0 or ~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:hpax, "~> 0.1.1", [hex: :hpax, repo: "hexpm", optional: false]}], "hexpm", "d77d9e9ce4eb35941907f1d3df38d8f750c357865353e21d335bdcdf6d892a02"},
+  "nimble_options": {:hex, :nimble_options, "1.1.0", "3b31a57ede9cb1502071fade751ab0c7b8dbe75a9a4c2b5bbb0943a690b63172", [:mix], [], "hexpm", "8bbbb3941af3ca9acc7835f5655ea062111c9c27bcac53e004460dfd19008a99"},
+  "nimble_pool": {:hex, :nimble_pool, "1.1.0", "bf9c29fbdcba3564a8b800d1eeb5a3c58f36e1e11d7b7fb2e084a643f645f06b", [:mix], [], "hexpm", "af2e4e6b34197db81f7aad230c1118eac993acc0dae6bc83bac0126d4ae0813a"},
   "phoenix": {:hex, :phoenix, "1.7.11", "1d88fc6b05ab0c735b250932c4e6e33bfa1c186f76dcf623d8dd52f07d6379c7", [:mix], [{:castore, ">= 0.0.0", [hex: :castore, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 2.1", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}, {:phoenix_template, "~> 1.0", [hex: :phoenix_template, repo: "hexpm", optional: false]}, {:phoenix_view, "~> 2.0", [hex: :phoenix_view, repo: "hexpm", optional: true]}, {:plug, "~> 1.14", [hex: :plug, repo: "hexpm", optional: false]}, {:plug_cowboy, "~> 2.7", [hex: :plug_cowboy, repo: "hexpm", optional: true]}, {:plug_crypto, "~> 1.2 or ~> 2.0", [hex: :plug_crypto, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}, {:websock_adapter, "~> 0.5.3", [hex: :websock_adapter, repo: "hexpm", optional: false]}], "hexpm", "b1ec57f2e40316b306708fe59b92a16b9f6f4bf50ccfa41aa8c7feb79e0ec02a"},
   "phoenix_ecto": {:hex, :phoenix_ecto, "4.5.1", "6fdbc334ea53620e71655664df6f33f670747b3a7a6c4041cdda3e2c32df6257", [:mix], [{:ecto, "~> 3.5", [hex: :ecto, repo: "hexpm", optional: false]}, {:phoenix_html, "~> 2.14.2 or ~> 3.0 or ~> 4.1", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:plug, "~> 1.9", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm", "ebe43aa580db129e54408e719fb9659b7f9e0d52b965c5be26cdca416ecead28"},
   "phoenix_pubsub": {:hex, :phoenix_pubsub, "2.1.3", "3168d78ba41835aecad272d5e8cd51aa87a7ac9eb836eabc42f6e57538e3731d", [:mix], [], "hexpm", "bba06bc1dcfd8cb086759f0edc94a8ba2bc8896d5331a1e2c2902bf8e36ee502"},