135 lines
		
	
	
	
		
			4.4 KiB
		
	
	
	
		
			Elixir
		
	
	
	
	
	
			
		
		
	
	
			135 lines
		
	
	
	
		
			4.4 KiB
		
	
	
	
		
			Elixir
		
	
	
	
	
	
| defmodule Pleroma.Web.MediaProxy.MediaProxyController do
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|   use Pleroma.Web, :controller
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|   require Logger
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| 
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|   @httpoison Application.get_env(:pleroma, :httpoison)
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| 
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|   @max_body_length 25 * 1_048_576
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| 
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|   @cache_control %{
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|     default: "public, max-age=1209600",
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|     error: "public, must-revalidate, max-age=160"
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|   }
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| 
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|   # Content-types that will not be returned as content-disposition attachments
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|   # Override with :media_proxy, :safe_content_types in the configuration
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|   @safe_content_types [
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|     "image/gif",
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|     "image/jpeg",
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|     "image/jpg",
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|     "image/png",
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|     "image/svg+xml",
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|     "audio/mpeg",
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|     "audio/mp3",
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|     "video/webm",
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|     "video/mp4"
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|   ]
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| 
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|   def remote(conn, params = %{"sig" => sig, "url" => url}) do
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|     config = Application.get_env(:pleroma, :media_proxy, [])
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| 
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|     with true <- Keyword.get(config, :enabled, false),
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|          {:ok, url} <- Pleroma.Web.MediaProxy.decode_url(sig, url),
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|          filename <- Path.basename(URI.parse(url).path),
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|          true <-
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|            if(Map.get(params, "filename"),
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|              do: filename == Path.basename(conn.request_path),
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|              else: true
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|            ),
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|          {:ok, content_type, body} <- proxy_request(url),
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|          safe_content_type <-
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|            Enum.member?(
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|              Keyword.get(config, :safe_content_types, @safe_content_types),
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|              content_type
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|            ) do
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|       conn
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|       |> put_resp_content_type(content_type)
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|       |> set_cache_header(:default)
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|       |> put_resp_header(
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|         "content-security-policy",
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|         "default-src 'none'; style-src 'unsafe-inline'; media-src data:; img-src 'self' data:"
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|       )
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|       |> put_resp_header("x-xss-protection", "1; mode=block")
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|       |> put_resp_header("x-content-type-options", "nosniff")
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|       |> put_attachement_header(safe_content_type, filename)
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|       |> send_resp(200, body)
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|     else
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|       false ->
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|         send_error(conn, 404)
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| 
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|       {:error, :invalid_signature} ->
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|         send_error(conn, 403)
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| 
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|       {:error, {:http, _, url}} ->
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|         redirect_or_error(conn, url, Keyword.get(config, :redirect_on_failure, true))
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|     end
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|   end
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| 
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|   defp proxy_request(link) do
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|     headers = [
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|       {"user-agent",
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|        "Pleroma/MediaProxy; #{Pleroma.Web.base_url()} <#{
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|          Application.get_env(:pleroma, :instance)[:email]
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|        }>"}
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|     ]
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| 
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|     options =
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|       @httpoison.process_request_options([:insecure, {:follow_redirect, true}]) ++
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|         [{:pool, :default}]
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| 
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|     with {:ok, 200, headers, client} <- :hackney.request(:get, link, headers, "", options),
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|          headers = Enum.into(headers, Map.new()),
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|          {:ok, body} <- proxy_request_body(client),
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|          content_type <- proxy_request_content_type(headers, body) do
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|       {:ok, content_type, body}
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|     else
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|       {:ok, status, _, _} ->
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|         Logger.warn("MediaProxy: request failed, status #{status}, link: #{link}")
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|         {:error, {:http, :bad_status, link}}
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| 
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|       {:error, error} ->
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|         Logger.warn("MediaProxy: request failed, error #{inspect(error)}, link: #{link}")
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|         {:error, {:http, error, link}}
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|     end
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|   end
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| 
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|   defp set_cache_header(conn, key) do
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|     Plug.Conn.put_resp_header(conn, "cache-control", @cache_control[key])
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|   end
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| 
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|   defp redirect_or_error(conn, url, true), do: redirect(conn, external: url)
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|   defp redirect_or_error(conn, url, _), do: send_error(conn, 502, "Media proxy error: " <> url)
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| 
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|   defp send_error(conn, code, body \\ "") do
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|     conn
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|     |> set_cache_header(:error)
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|     |> send_resp(code, body)
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|   end
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| 
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|   defp proxy_request_body(client), do: proxy_request_body(client, <<>>)
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| 
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|   defp proxy_request_body(client, body) when byte_size(body) < @max_body_length do
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|     case :hackney.stream_body(client) do
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|       {:ok, data} -> proxy_request_body(client, <<body::binary, data::binary>>)
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|       :done -> {:ok, body}
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|       {:error, reason} -> {:error, reason}
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|     end
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|   end
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| 
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|   defp proxy_request_body(client, _) do
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|     :hackney.close(client)
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|     {:error, :body_too_large}
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|   end
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| 
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|   # TODO: the body is passed here as well because some hosts do not provide a content-type.
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|   # At some point we may want to use magic numbers to discover the content-type and reply a proper one.
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|   defp proxy_request_content_type(headers, _body) do
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|     headers["Content-Type"] || headers["content-type"] || "application/octet-stream"
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|   end
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| 
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|   defp put_attachement_header(conn, true, _), do: conn
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| 
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|   defp put_attachement_header(conn, false, filename) do
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|     put_resp_header(conn, "content-disposition", "attachment; filename='#{filename}'")
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|   end
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| end
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