add basic floof handling

lib/chat/application.ex

@@ -4,6 +4,7 @@ defmodule Chat.Application do
   @moduledoc false
 
   use Application
+  require Logger
 
   @impl true
   def start(_type, _args) do
@@ -13,9 +14,17 @@ defmodule Chat.Application do
       # Start the PubSub system
       {Phoenix.PubSub, name: Chat.PubSub},
       # Start the Endpoint (http/https)
-      ChatWeb.Endpoint
+      ChatWeb.Endpoint,
       # Start a worker by calling: Chat.Worker.start_link(arg)
       # {Chat.Worker, arg}
+      # Start the message handler
+      Chat.Floof,
+
+      # Start the relay
+      {Task, fn ->
+        Floof.Distributor.register(self())
+        relay_loop()
+      end}
     ]
 
     # See https://hexdocs.pm/elixir/Supervisor.html
@@ -31,4 +40,20 @@ defmodule Chat.Application do
     ChatWeb.Endpoint.config_change(changed, removed)
     :ok
   end
+
+  defp relay_loop do
+    receive do
+      {:fwdxfer, {_, {:XferBlob, source, _, _, _, xfinner}}} ->
+        {:ok, dcdi} = :FloofProtocol.decode(:XferInner, xfinner)
+        {:XferInner, topic, attrs, _, data} = dcdi
+        if topic == [{:RelativeDistinguishedName, {0, 9, 2342, 19200300, 100, 1, 14}, "Chat"}] do
+          [{:RelativeDistinguishedName, {0, 9, 2342, 19200300, 100, 1, 4}, name}] = attrs
+          {:ok, source_encd} = :FloofProtocol.encode(:RDNSequence, source)
+          source_encd = Base.url_encode64(source_encd)
+          ChatWeb.Endpoint.broadcast!("room:lobby", "shout", %{name: source_encd <> " :: " <> name, message: data})
+        end
+      x -> Logger.error("unable to handle message #{inspect(x)}")
+    end
+    relay_loop()
+  end
 end

lib/chat/floof.ex

@@ -0,0 +1,37 @@
+defmodule Chat.Floof do
+  use Agent
+  require Logger
+
+  defstruct secret: "", source: []
+
+  def start_link do
+    Agent.start_link(fn ->
+      secret_file = Application.fetch_env!(:chat, :secret_file)
+      source = Application.fetch_env!(:chat, :source)
+      {:ok, secret} = File.read(secret_file)
+      %Chat.Floof{secret: secret, source: source}
+    end, name: __MODULE__)
+  end
+
+  def setup do
+    # generate and save a keypair
+    kp = :enacl.sign_keypair()
+    secret_file = Application.fetch_env!(:chat, :secret_file)
+    source = Application.fetch_env!(:chat, :source)
+    :ok = File.write(secret_file, kp.secret)
+    {:ok, pkname} = :FloofProtocol.encode(:RDNSequence, source)
+    pubkey_config = Application.fetch_env!(:floof, :pubkey_config)
+    :ok = File.write(pubkey_config.keydb <> "/" <> Base.url_encode64(pkname), kp.public)
+  end
+
+  def send_message(name, data) do
+    msg_topic = [{:RelativeDistinguishedName, {0, 9, 2342, 19200300, 100, 1, 14}, "Chat"}]
+    msg_attrs = [{:RelativeDistinguishedName, {0, 9, 2342, 19200300, 100, 1, 4}, name}]
+    msg_inner = Floof.Message.pack_inner(msg_topic, msg_attrs, :info, data)
+    Agent.cast(__MODULE__, fn state ->
+      msg_outer = Floof.Message.build_outer(state.source, 255, [], state.secret, msg_inner)
+      Floof.Message.emit(msg_outer)
+      state
+    end)
+  end
+end

lib/chat_web/channels/room_channel.ex

@@ -21,6 +21,7 @@ defmodule ChatWeb.RoomChannel do
   # broadcast to everyone in the current topic (room:lobby).
   @impl true
   def handle_in("shout", payload, socket) do
+    Chat.Floof.send_message(payload.name, payload.message)
     broadcast(socket, "shout", payload)
     {:noreply, socket}
   end

mix.exs

@@ -46,7 +46,8 @@ defmodule Chat.MixProject do
       {:gettext, "~> 0.18"},
       {:jason, "~> 1.2"},
       {:plug_cowboy, "~> 2.5"},
-      {:floof, git: "https://git.exozy.me/zseri/floof.git"}
+      {:floof, git: "https://git.exozy.me/zseri/floof.git"},
+      {:enacl, "~> 1.0.0"}
     ]
   end