logicmason · December 19, 2016 16:43 · Dec 19, 2016
diff --git a/auth_controller.ex b/auth_controller.ex
@@ -0,0 +1,12 @@
+# my_app/web/controllers/auth_controller.ex
+defmodule MyApp.AuthController do
+  use MyApp.Web, :controller
+  import Ecto.Query
+  alias MyApp.TwilioToken
+
+  # Connect this to a route for /token:identity
+  def token(conn, %{"identity" => identity}) do
+    token = TwilioToken.for_video(identity)
+    json conn, %{token: token, identity: identity}
+  end
+ end
diff --git a/twilio_token.ex b/twilio_token.ex
@@ -0,0 +1,42 @@
+# my_app/web/twilio_token.ex
+defmodule MyApp.TwilioToken do
+  # Generates token for Twilio Programmable video
+  # Assumes Joken is in Mix.exs deps and Twilio creds are in app config
+  def for_video(identity) do
+    sid = config[:TWILIO_ACCOUNT_SID]
+    api_key = config[:TWILIO_API_KEY]
+    api_secret = config[:TWILIO_API_SECRET]
+    rtc_profile_sid = config[:TWILIO_CONFIGURATION_SID]
+    now = epoch_ts()
+    exp = now + 3600
+
+    payload = %{
+      "jti" => "#{api_key}-#{now}",
+      "iss" => api_key,
+      "sub" => sid,
+      "exp" => exp,
+      "grants" => %{
+        "identity" => identity,
+        "rtc" => %{
+          "configuration_profile_sid" => rtc_profile_sid
+        }
+      }
+    }
+
+    payload
+    |> Joken.token()
+    |> Joken.with_header_arg("cty", "twilio-fpa;v=1")
+    |> Joken.with_signer(Joken.hs256(api_secret))
+    |> Joken.sign()
+    |> Joken.get_compact()
+  end
+
+  defp epoch_ts() do
+    epoch = {{1970, 1, 1}, {0, 0, 0}}
+    epoch_i = :calendar.datetime_to_gregorian_seconds(epoch)
+    now_i = :calendar.datetime_to_gregorian_seconds(:calendar.universal_time)
+    now_i - epoch_i
+  end
+
+  def config, do: Application.get_env(:my_app, __MODULE__)
+end