2 files changed, 74 insertions, 68 deletions

diff --git a/lib/pleroma/web/mastodon_api/websocket_handler.ex b/lib/pleroma/web/mastodon_api/websocket_handler.ex
index 393d093e5..94e4595d8 100644
--- a/lib/pleroma/web/mastodon_api/websocket_handler.ex
+++ b/lib/pleroma/web/mastodon_api/websocket_handler.ex
@@ -19,26 +19,12 @@ defmodule Pleroma.Web.MastodonAPI.WebsocketHandler do
   # Hibernate every X messages
   @hibernate_every 100
 
-  @streams [
-    "public",
-    "public:local",
-    "public:media",
-    "public:local:media",
-    "user",
-    "user:notification",
-    "direct",
-    "list",
-    "hashtag"
-  ]
-  @anonymous_streams ["public", "public:local", "hashtag"]
-
   def init(%{qs: qs} = req, state) do
-    with params <- :cow_qs.parse_qs(qs),
+    with params <- Enum.into(:cow_qs.parse_qs(qs), %{}),
          sec_websocket <- :cowboy_req.header("sec-websocket-protocol", req, nil),
-         access_token <- List.keyfind(params, "access_token", 0),
-         {_, stream} <- List.keyfind(params, "stream", 0),
-         {:ok, user} <- allow_request(stream, [access_token, sec_websocket]),
-         topic when is_binary(topic) <- expand_topic(stream, params) do
+         access_token <- Map.get(params, "access_token"),
+         {:ok, user} <- authenticate_request(access_token, sec_websocket),
+         {:ok, topic} <- Streamer.get_topic(Map.get(params, "stream"), user, params) do
       req =
         if sec_websocket do
           :cowboy_req.set_resp_header("sec-websocket-protocol", sec_websocket, req)
@@ -49,14 +35,14 @@ defmodule Pleroma.Web.MastodonAPI.WebsocketHandler do
       {:cowboy_websocket, req, %{user: user, topic: topic, count: 0, timer: nil},
        %{idle_timeout: @timeout}}
     else
-      {:error, code} ->
-        Logger.debug("#{__MODULE__} denied connection: #{inspect(code)} - #{inspect(req)}")
-        {:ok, req} = :cowboy_req.reply(code, req)
+      {:error, :bad_topic} ->
+        Logger.debug("#{__MODULE__} bad topic #{inspect(req)}")
+        {:ok, req} = :cowboy_req.reply(404, req)
         {:ok, req, state}
 
-      error ->
-        Logger.debug("#{__MODULE__} denied connection: #{inspect(error)} - #{inspect(req)}")
-        {:ok, req} = :cowboy_req.reply(400, req)
+      {:error, :unauthorized} ->
+        Logger.debug("#{__MODULE__} authentication error: #{inspect(req)}")
+        {:ok, req} = :cowboy_req.reply(401, req)
         {:ok, req, state}
     end
   end
@@ -124,50 +110,23 @@ defmodule Pleroma.Web.MastodonAPI.WebsocketHandler do
   end
 
   # Public streams without authentication.
-  defp allow_request(stream, [nil, nil]) when stream in @anonymous_streams do
+  defp authenticate_request(nil, nil) do
     {:ok, nil}
   end
 
   # Authenticated streams.
-  defp allow_request(stream, [access_token, sec_websocket]) when stream in @streams do
-    token =
-      with {"access_token", token} <- access_token do
-        token
-      else
-        _ -> sec_websocket
-      end
+  defp authenticate_request(access_token, sec_websocket) do
+    token = access_token || sec_websocket
 
     with true <- is_bitstring(token),
          %Token{user_id: user_id} <- Repo.get_by(Token, token: token),
          user = %User{} <- User.get_cached_by_id(user_id) do
       {:ok, user}
     else
-      _ -> {:error, 403}
-    end
-  end
-
-  # Not authenticated.
-  defp allow_request(stream, _) when stream in @streams, do: {:error, 403}
-
-  # No matching stream.
-  defp allow_request(_, _), do: {:error, 404}
-
-  defp expand_topic("hashtag", params) do
-    case List.keyfind(params, "tag", 0) do
-      {_, tag} -> "hashtag:#{tag}"
-      _ -> nil
+      _ -> {:error, :unauthorized}
     end
   end
 
-  defp expand_topic("list", params) do
-    case List.keyfind(params, "list", 0) do
-      {_, list} -> "list:#{list}"
-      _ -> nil
-    end
-  end
-
-  defp expand_topic(topic, _), do: topic
-
   defp timer do
     Process.send_after(self(), :tick, @tick)
   end
diff --git a/lib/pleroma/web/streamer/streamer.ex b/lib/pleroma/web/streamer/streamer.ex
index 5ad4aa936..49a400df7 100644
--- a/lib/pleroma/web/streamer/streamer.ex
+++ b/lib/pleroma/web/streamer/streamer.ex
@@ -21,12 +21,68 @@ defmodule Pleroma.Web.Streamer do
 
   def registry, do: @registry
 
-  def add_socket(topic, %User{} = user) do
-    if should_env_send?(), do: Registry.register(@registry, user_topic(topic, user), true)
+  @public_streams ["public", "public:local", "public:media", "public:local:media"]
+  @user_streams ["user", "user:notification", "direct"]
+
+  @doc "Expands and authorizes a stream, and registers the process for streaming."
+  @spec get_topic_and_add_socket(stream :: String.t(), User.t() | nil, Map.t() | nil) ::
+          {:ok, topic :: String.t()} | {:error, :bad_topic} | {:error, :unauthorized}
+  def get_topic_and_add_socket(stream, user, params \\ %{}) do
+    case get_topic(stream, user, params) do
+      {:ok, topic} -> add_socket(topic, user)
+      error -> error
+    end
+  end
+
+  @doc "Expand and authorizes a stream"
+  @spec get_topic(stream :: String.t(), User.t() | nil, Map.t()) ::
+          {:ok, topic :: String.t()} | {:error, :bad_topic}
+  def get_topic(stream, user, params \\ %{})
+
+  # Allow all public steams.
+  def get_topic(stream, _, _) when stream in @public_streams do
+    {:ok, stream}
   end
 
-  def add_socket(topic, _) do
-    if should_env_send?(), do: Registry.register(@registry, topic, false)
+  # Allow all hashtags streams.
+  def get_topic("hashtag", _, %{"tag" => tag}) do
+    {:ok, "hashtag:" <> tag}
+  end
+
+  # Expand user streams.
+  def get_topic(stream, %User{} = user, _) when stream in @user_streams do
+    {:ok, stream <> ":" <> to_string(user.id)}
+  end
+
+  def get_topic(stream, _, _) when stream in @user_streams do
+    {:error, :unauthorized}
+  end
+
+  # List streams.
+  def get_topic("list", %User{} = user, %{"list" => id}) do
+    if Pleroma.List.get(id, user) do
+      {:ok, "list:" <> to_string(id)}
+    else
+      {:error, :bad_topic}
+    end
+  end
+
+  def get_topic("list", _, _) do
+    {:error, :unauthorized}
+  end
+
+  def get_topic(_, _, _) do
+    {:error, :bad_topic}
+  end
+
+  @doc "Registers the process for streaming. Use `get_topic/3` to get the full authorized topic."
+  def add_socket(topic, user) do
+    if should_env_send?() do
+      auth? = if user, do: true
+      Registry.register(@registry, topic, auth?)
+    end
+
+    {:ok, topic}
   end
 
   def remove_socket(topic) do
@@ -231,13 +287,4 @@ defmodule Pleroma.Web.Streamer do
     true ->
       def should_env_send?, do: true
   end
-
-  defp user_topic(topic, user)
-       when topic in ~w[user user:notification direct] do
-    "#{topic}:#{user.id}"
-  end
-
-  defp user_topic(topic, _) do
-    topic
-  end
 end