129 lines
		
	
	
	
		
			3.3 KiB
		
	
	
	
		
			Elixir
		
	
	
	
	
	
			
		
		
	
	
			129 lines
		
	
	
	
		
			3.3 KiB
		
	
	
	
		
			Elixir
		
	
	
	
	
	
| # Pleroma: A lightweight social networking server
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| # Copyright _ 2017-2020 Pleroma Authors <https://pleroma.social/>
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| # SPDX-License-Identifier: AGPL-3.0-only
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| 
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| defmodule Pleroma.Web.RichMedia.Helpers do
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|   alias Pleroma.Activity
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|   alias Pleroma.Config
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|   alias Pleroma.HTML
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|   alias Pleroma.Object
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|   alias Pleroma.Web.RichMedia.Parser
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| 
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|   @options [
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|     max_body: 2_000_000,
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|     receive_timeout: 2_000
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|   ]
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| 
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|   @spec validate_page_url(URI.t() | binary()) :: :ok | :error
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|   defp validate_page_url(page_url) when is_binary(page_url) do
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|     validate_tld = Config.get([Pleroma.Formatter, :validate_tld])
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| 
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|     page_url
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|     |> Linkify.Parser.url?(validate_tld: validate_tld)
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|     |> parse_uri(page_url)
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|   end
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| 
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|   defp validate_page_url(%URI{host: host, scheme: "https", authority: authority})
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|        when is_binary(authority) do
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|     cond do
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|       host in Config.get([:rich_media, :ignore_hosts], []) ->
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|         :error
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| 
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|       get_tld(host) in Config.get([:rich_media, :ignore_tld], []) ->
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|         :error
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| 
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|       true ->
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|         :ok
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|     end
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|   end
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| 
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|   defp validate_page_url(_), do: :error
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| 
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|   defp parse_uri(true, url) do
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|     url
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|     |> URI.parse()
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|     |> validate_page_url
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|   end
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| 
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|   defp parse_uri(_, _), do: :error
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| 
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|   defp get_tld(host) do
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|     host
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|     |> String.split(".")
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|     |> Enum.reverse()
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|     |> hd
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|   end
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| 
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|   def fetch_data_for_object(object) do
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|     with true <- Config.get([:rich_media, :enabled]),
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|          {:ok, page_url} <-
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|            HTML.extract_first_external_url_from_object(object),
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|          :ok <- validate_page_url(page_url),
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|          {:ok, rich_media} <- Parser.parse(page_url) do
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|       %{page_url: page_url, rich_media: rich_media}
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|     else
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|       _ -> %{}
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|     end
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|   end
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| 
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|   def fetch_data_for_activity(%Activity{data: %{"type" => "Create"}} = activity) do
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|     with true <- Config.get([:rich_media, :enabled]),
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|          %Object{} = object <- Object.normalize(activity, fetch: false) do
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|       fetch_data_for_object(object)
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|     else
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|       _ -> %{}
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|     end
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|   end
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| 
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|   def fetch_data_for_activity(_), do: %{}
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| 
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|   def rich_media_get(url) do
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|     headers = [{"user-agent", Pleroma.Application.user_agent() <> "; Bot"}]
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| 
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|     head_check =
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|       case Pleroma.HTTP.head(url, headers, @options) do
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|         # If the HEAD request didn't reach the server for whatever reason,
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|         # we assume the GET that comes right after won't either
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|         {:error, _} = e ->
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|           e
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| 
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|         {:ok, %Tesla.Env{status: 200, headers: headers}} ->
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|           with :ok <- check_content_type(headers),
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|                :ok <- check_content_length(headers),
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|                do: :ok
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| 
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|         _ ->
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|           :ok
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|       end
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| 
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|     with :ok <- head_check, do: Pleroma.HTTP.get(url, headers, @options)
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|   end
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| 
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|   defp check_content_type(headers) do
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|     case List.keyfind(headers, "content-type", 0) do
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|       {_, content_type} ->
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|         case Plug.Conn.Utils.media_type(content_type) do
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|           {:ok, "text", "html", _} -> :ok
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|           _ -> {:error, {:content_type, content_type}}
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|         end
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| 
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|       _ ->
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|         :ok
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|     end
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|   end
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| 
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|   @max_body @options[:max_body]
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|   defp check_content_length(headers) do
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|     case List.keyfind(headers, "content-length", 0) do
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|       {_, maybe_content_length} ->
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|         case Integer.parse(maybe_content_length) do
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|           {content_length, ""} when content_length <= @max_body -> :ok
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|           {_, ""} -> {:error, :body_too_large}
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|           _ -> :ok
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|         end
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| 
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|       _ ->
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|         :ok
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|     end
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|   end
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| end
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