1 # Pleroma: A lightweight social networking server
2 # Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
3 # SPDX-License-Identifier: AGPL-3.0-only
5 defmodule Pleroma.Web.ActivityPub.MRF.StealEmojiPolicy do
10 @moduledoc "Detect new emojis by their shortcode and steals them"
11 @behaviour Pleroma.Web.ActivityPub.MRF
13 defp remote_host?(host), do: host != Config.get([Pleroma.Web.Endpoint, :url, :host])
15 defp accept_host?(host), do: host in Config.get([:mrf_steal_emoji, :hosts], [])
17 defp steal_emoji({shortcode, url}) do
18 url = Pleroma.Web.MediaProxy.url(url)
19 {:ok, response} = Pleroma.HTTP.get(url)
20 size_limit = Config.get([:mrf_steal_emoji, :size_limit], 50_000)
22 if byte_size(response.body) <= size_limit do
25 [:mrf_steal_emoji, :path],
26 Path.join(Config.get([:instance, :static_dir]), "emoji/stolen")
36 file_path = Path.join([emoji_dir_path, shortcode <> (extension || ".png")])
39 :ok = File.write(file_path, response.body)
44 Logger.warn("MRF.StealEmojiPolicy: Failed to write to #{file_path}: #{inspect(e)}")
49 "MRF.StealEmojiPolicy: :#{shortcode}: at #{url} (#{byte_size(response.body)} B) over size limit (#{
58 Logger.warn("MRF.StealEmojiPolicy: Failed to fetch #{url}: #{inspect(e)}")
63 def filter(%{"object" => %{"emoji" => foreign_emojis, "actor" => actor}} = message) do
64 host = URI.parse(actor).host
66 if remote_host?(host) and accept_host?(host) do
67 installed_emoji = Pleroma.Emoji.get_all() |> Enum.map(fn {k, _} -> k end)
71 |> Enum.filter(fn {shortcode, _url} -> shortcode not in installed_emoji end)
72 |> Enum.filter(fn {shortcode, _url} ->
74 Config.get([:mrf_steal_emoji, :rejected_shortcodes], [])
75 |> Enum.find(false, fn regex -> String.match?(shortcode, regex) end)
79 |> Enum.map(&steal_emoji(&1))
82 if !Enum.empty?(new_emojis) do
83 Logger.info("Stole new emojis: #{inspect(new_emojis)}")
84 Pleroma.Emoji.reload()
91 def filter(message), do: {:ok, message}