From b19597f602e70121a1762476873377c782549817 Mon Sep 17 00:00:00 2001
From: href <href@random.sh>
Date: Fri, 23 Nov 2018 17:40:45 +0100
Subject: [PATCH] reverse proxy / uploads

---
 .gitignore                                    |   5 +-
 config/config.exs                             |  19 +-
 config/test.exs                               |   2 +-
 lib/mix/tasks/migrate_local_uploads.ex        |  80 +++++
 lib/pleroma/application.ex                    |   5 +
 lib/pleroma/plugs/uploaded_media.ex           |  78 ++++
 lib/pleroma/reverse_proxy.ex                  | 338 ++++++++++++++++++
 lib/pleroma/upload.ex                         | 200 ++++++-----
 lib/pleroma/uploaders/local.ex                |  26 +-
 lib/pleroma/uploaders/mdii.ex                 |  12 +-
 lib/pleroma/uploaders/s3.ex                   |  50 +--
 lib/pleroma/uploaders/swift/swift.ex          |   2 +-
 lib/pleroma/uploaders/swift/uploader.ex       |   6 +-
 lib/pleroma/uploaders/uploader.ex             |  27 +-
 lib/pleroma/web/activity_pub/activity_pub.ex  |   6 +-
 lib/pleroma/web/endpoint.ex                   |   2 +-
 .../mastodon_api/mastodon_api_controller.ex   |   4 +-
 lib/pleroma/web/media_proxy/controller.ex     | 135 +------
 lib/pleroma/web/media_proxy/media_proxy.ex    |  20 +-
 lib/pleroma/web/twitter_api/twitter_api.ex    |   2 +-
 .../web/twitter_api/twitter_api_controller.ex |   7 +-
 test/support/httpoison_mock.ex                |   2 +
 test/upload_test.exs                          |  42 ++-
 23 files changed, 790 insertions(+), 280 deletions(-)
 create mode 100644 lib/mix/tasks/migrate_local_uploads.ex
 create mode 100644 lib/pleroma/plugs/uploaded_media.ex
 create mode 100644 lib/pleroma/reverse_proxy.ex

diff --git a/.gitignore b/.gitignore
index 9aad700ee..b71dfa9fa 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,9 @@
 /uploads
 /test/uploads
 /.elixir_ls
+/test/fixtures/test_tmp.txt
+/test/fixtures/image_tmp.jpg
+/doc
 
 # Prevent committing custom emojis
 /priv/static/emoji/custom/*
@@ -28,4 +31,4 @@ erl_crash.dump
 .env
 
 # Editor config
-/.vscode
\ No newline at end of file
+/.vscode
diff --git a/config/config.exs b/config/config.exs
index 848c9d6cf..ee43071ea 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -12,16 +12,15 @@
 
 config :pleroma, Pleroma.Upload,
   uploader: Pleroma.Uploaders.Local,
-  strip_exif: false
+  strip_exif: false,
+  proxy_remote: false,
+  proxy_opts: [inline_content_types: true, keep_user_agent: true]
 
-config :pleroma, Pleroma.Uploaders.Local,
-  uploads: "uploads",
-  uploads_url: "{{base_url}}/media/{{file}}"
+config :pleroma, Pleroma.Uploaders.Local, uploads: "uploads"
 
 config :pleroma, Pleroma.Uploaders.S3,
   bucket: nil,
-  public_endpoint: "https://s3.amazonaws.com",
-  force_media_proxy: false
+  public_endpoint: "https://s3.amazonaws.com"
 
 config :pleroma, Pleroma.Uploaders.MDII,
   cgi: "https://mdii.sakura.ne.jp/mdii-post.cgi",
@@ -150,9 +149,11 @@
 
 config :pleroma, :media_proxy,
   enabled: false,
-  redirect_on_failure: true
-
-# base_url: "https://cache.pleroma.social"
+  # base_url: "https://cache.pleroma.social",
+  proxy_opts: [
+    # inline_content_types: [] | false | true,
+    # http: [:insecure]
+  ]
 
 config :pleroma, :chat, enabled: true
 
diff --git a/config/test.exs b/config/test.exs
index 1bd11dee4..3aaed1b2c 100644
--- a/config/test.exs
+++ b/config/test.exs
@@ -9,7 +9,7 @@
 # Print only warnings and errors during test
 config :logger, level: :warn
 
-config :pleroma, Pleroma.Upload, uploads: "test/uploads"
+config :pleroma, Pleroma.Uploaders.Local, uploads: "test/uploads"
 
 # Configure your database
 config :pleroma, Pleroma.Repo,
diff --git a/lib/mix/tasks/migrate_local_uploads.ex b/lib/mix/tasks/migrate_local_uploads.ex
new file mode 100644
index 000000000..40117350c
--- /dev/null
+++ b/lib/mix/tasks/migrate_local_uploads.ex
@@ -0,0 +1,80 @@
+defmodule Mix.Tasks.MigrateLocalUploads do
+  use Mix.Task
+  import Mix.Ecto
+  alias Pleroma.{Upload, Uploaders.Local, Uploaders.S3}
+  require Logger
+
+  @log_every 50
+  @shortdoc "Migrate uploads from local to remote storage"
+
+  def run([target_uploader | args]) do
+    delete? = Enum.member?(args, "--delete")
+    Application.ensure_all_started(:pleroma)
+
+    local_path = Pleroma.Config.get!([Local, :uploads])
+    uploader = Module.concat(Pleroma.Uploaders, target_uploader)
+
+    unless Code.ensure_loaded?(uploader) do
+      raise("The uploader #{inspect(uploader)} is not an existing/loaded module.")
+    end
+
+    target_enabled? = Pleroma.Config.get([Upload, :uploader]) == uploader
+
+    unless target_enabled? do
+      Pleroma.Config.put([Upload, :uploader], uploader)
+    end
+
+    Logger.info("Migrating files from local #{local_path} to #{to_string(uploader)}")
+
+    if delete? do
+      Logger.warn(
+        "Attention: uploaded files will be deleted, hope you have backups! (--delete ; cancel with ^C)"
+      )
+
+      :timer.sleep(:timer.seconds(5))
+    end
+
+    uploads = File.ls!(local_path)
+    total_count = length(uploads)
+
+    uploads
+    |> Task.async_stream(
+      fn uuid ->
+        u_path = Path.join(local_path, uuid)
+
+        {name, path} =
+          cond do
+            File.dir?(u_path) ->
+              files = for file <- File.ls!(u_path), do: {{file, uuid}, Path.join([u_path, file])}
+              List.first(files)
+
+            File.exists?(u_path) ->
+              # {uuid, u_path}
+              raise "should_dedupe local storage not supported yet sorry"
+          end
+
+        {:ok, _} =
+          Upload.store({:from_local, name, path}, should_dedupe: false, uploader: uploader)
+
+        if delete? do
+          File.rm_rf!(u_path)
+        end
+
+        Logger.debug("uploaded: #{inspect(name)}")
+      end,
+      timeout: 150_000
+    )
+    |> Stream.chunk_every(@log_every)
+    |> Enum.reduce(0, fn done, count ->
+      count = count + length(done)
+      Logger.info("Uploaded #{count}/#{total_count} files")
+      count
+    end)
+
+    Logger.info("Done!")
+  end
+
+  def run(_) do
+    Logger.error("Usage: migrate_local_uploads UploaderName [--delete]")
+  end
+end
diff --git a/lib/pleroma/application.ex b/lib/pleroma/application.ex
index 2d86efae5..ca5b9fe65 100644
--- a/lib/pleroma/application.ex
+++ b/lib/pleroma/application.ex
@@ -7,6 +7,11 @@ def name, do: @name
   def version, do: @version
   def named_version(), do: @name <> " " <> @version
 
+  def user_agent() do
+    info = "#{Pleroma.Web.base_url()} <#{Pleroma.Config.get([:instance, :email], "")}>"
+    named_version() <> "; " <> info
+  end
+
   # See http://elixir-lang.org/docs/stable/elixir/Application.html
   # for more information on OTP Applications
   @env Mix.env()
diff --git a/lib/pleroma/plugs/uploaded_media.ex b/lib/pleroma/plugs/uploaded_media.ex
new file mode 100644
index 000000000..994cc8bf6
--- /dev/null
+++ b/lib/pleroma/plugs/uploaded_media.ex
@@ -0,0 +1,78 @@
+defmodule Pleroma.Plugs.UploadedMedia do
+  @moduledoc """
+  """
+
+  import Plug.Conn
+  require Logger
+
+  @behaviour Plug
+  # no slashes
+  @path "media"
+  @cache_control %{
+    default: "public, max-age=1209600",
+    error: "public, must-revalidate, max-age=160"
+  }
+
+  def init(_opts) do
+    static_plug_opts =
+      []
+      |> Keyword.put(:from, "__unconfigured_media_plug")
+      |> Keyword.put(:at, "/__unconfigured_media_plug")
+      |> Plug.Static.init()
+
+    %{static_plug_opts: static_plug_opts}
+  end
+
+  def call(conn = %{request_path: <<"/", @path, "/", file::binary>>}, opts) do
+    config = Pleroma.Config.get([Pleroma.Upload])
+
+    with uploader <- Keyword.fetch!(config, :uploader),
+         proxy_remote = Keyword.get(config, :proxy_remote, false),
+         {:ok, get_method} <- uploader.get_file(file) do
+      get_media(conn, get_method, proxy_remote, opts)
+    else
+      _ ->
+        conn
+        |> send_resp(500, "Failed")
+        |> halt()
+    end
+  end
+
+  def call(conn, _opts), do: conn
+
+  defp get_media(conn, {:static_dir, directory}, _, opts) do
+    static_opts =
+      Map.get(opts, :static_plug_opts)
+      |> Map.put(:at, [@path])
+      |> Map.put(:from, directory)
+
+    conn = Plug.Static.call(conn, static_opts)
+
+    if conn.halted do
+      conn
+    else
+      conn
+      |> send_resp(404, "Not found")
+      |> halt()
+    end
+  end
+
+  defp get_media(conn, {:url, url}, true, _) do
+    conn
+    |> Pleroma.ReverseProxy.call(url, Pleroma.Config.get([Pleroma.Upload, :proxy_opts], []))
+  end
+
+  defp get_media(conn, {:url, url}, _, _) do
+    conn
+    |> Phoenix.Controller.redirect(external: url)
+    |> halt()
+  end
+
+  defp get_media(conn, unknown, _, _) do
+    Logger.error("#{__MODULE__}: Unknown get startegy: #{inspect(unknown)}")
+
+    conn
+    |> send_resp(500, "Internal Error")
+    |> halt()
+  end
+end
diff --git a/lib/pleroma/reverse_proxy.ex b/lib/pleroma/reverse_proxy.ex
new file mode 100644
index 000000000..64c3c3a19
--- /dev/null
+++ b/lib/pleroma/reverse_proxy.ex
@@ -0,0 +1,338 @@
+defmodule Pleroma.ReverseProxy do
+  @keep_req_headers ~w(accept user-agent accept-encoding cache-control if-modified-since if-none-match range)
+  @resp_cache_headers ~w(etag date last-modified cache-control)
+  @keep_resp_headers @resp_cache_headers ++
+                       ~w(content-type content-disposition content-length accept-ranges vary)
+  @default_cache_control_header "public, max-age=1209600"
+  @valid_resp_codes [200, 206, 304]
+  @max_read_duration :timer.minutes(2)
+  @max_body_length :infinity
+  @methods ~w(GET HEAD)
+
+  @moduledoc """
+  A reverse proxy.
+
+      Pleroma.ReverseProxy.call(conn, url, options)
+
+  It is not meant to be added into a plug pipeline, but to be called from another plug or controller.
+
+  Supports `#{inspect(@methods)}` HTTP methods, and only allows `#{inspect(@valid_resp_codes)}` status codes.
+
+  Responses are chunked to the client while downloading from the upstream.
+
+  Some request / responses headers are preserved:
+
+  * request: `#{inspect(@keep_req_headers)}`
+  * response: `#{inspect(@keep_resp_headers)}`
+
+  If no caching headers (`#{inspect(@resp_cache_headers)}`) are returned by upstream, `cache-control` will be
+  set to `#{inspect(@default_cache_control_header)}`.
+
+  Options:
+
+  * `redirect_on_failure` (default `false`). Redirects the client to the real remote URL if there's any HTTP
+  errors. Any error during body processing will not be redirected as the response is chunked. This may expose
+  remote URL, clients IPs, ….
+
+  * `max_body_length` (default `#{inspect(@max_body_length)}`): limits the content length to be approximately the
+  specified length. It is validated with the `content-length` header and also verified when proxying.
+
+  * `max_read_duration` (default `#{inspect(@max_read_duration)}` ms): the total time the connection is allowed to
+  read from the remote upstream.
+
+  * `inline_content_types`:
+    * `true` will not alter `content-disposition` (up to the upstream),
+    * `false` will add `content-disposition: attachment` to any request,
+    * a list of whitelisted content types
+
+    * `keep_user_agent` will forward the client's user-agent to the upstream. This may be useful if the upstream is
+    doing content transformation (encoding, …) depending on the request.
+
+  * `req_headers`, `resp_headers` additional headers.
+
+  * `http`: options for [hackney](https://github.com/benoitc/hackney).
+
+  """
+  @hackney Application.get_env(:pleroma, :hackney, :hackney)
+  @httpoison Application.get_env(:pleroma, :httpoison, HTTPoison)
+
+  @default_hackney_options [{:follow_redirect, true}]
+
+  @inline_content_types [
+    "image/gif",
+    "image/jpeg",
+    "image/jpg",
+    "image/png",
+    "image/svg+xml",
+    "audio/mpeg",
+    "audio/mp3",
+    "video/webm",
+    "video/mp4",
+    "video/quicktime"
+  ]
+
+  require Logger
+  import Plug.Conn
+
+  @type option() ::
+          {:keep_user_agent, boolean}
+          | {:max_read_duration, :timer.time() | :infinity}
+          | {:max_body_length, non_neg_integer() | :infinity}
+          | {:http, []}
+          | {:req_headers, [{String.t(), String.t()}]}
+          | {:resp_headers, [{String.t(), String.t()}]}
+          | {:inline_content_types, boolean() | [String.t()]}
+          | {:redirect_on_failure, boolean()}
+
+  @spec call(Plug.Conn.t(), url :: String.t(), [option()]) :: Plug.Conn.t()
+  def call(conn = %{method: method}, url, opts \\ []) when method in @methods do
+    hackney_opts =
+      @default_hackney_options
+      |> Keyword.merge(Keyword.get(opts, :http, []))
+      |> @httpoison.process_request_options()
+
+    req_headers = build_req_headers(conn.req_headers, opts)
+
+    opts =
+      if filename = Pleroma.Web.MediaProxy.filename(url) do
+        Keyword.put_new(opts, :attachment_name, filename)
+      else
+        opts
+      end
+
+    with {:ok, code, headers, client} <- request(method, url, req_headers, hackney_opts),
+         :ok <- header_lenght_constraint(headers, Keyword.get(opts, :max_body_length)) do
+      response(conn, client, url, code, headers, opts)
+    else
+      {:ok, code, headers} ->
+        head_response(conn, url, code, headers, opts)
+        |> halt()
+
+      {:error, {:invalid_http_response, code}} ->
+        Logger.error("#{__MODULE__}: request to #{inspect(url)} failed with HTTP status #{code}")
+
+        conn
+        |> error_or_redirect(
+          url,
+          code,
+          "Request failed: " <> Plug.Conn.Status.reason_phrase(code),
+          opts
+        )
+        |> halt()
+
+      {:error, error} ->
+        Logger.error("#{__MODULE__}: request to #{inspect(url)} failed: #{inspect(error)}")
+
+        conn
+        |> error_or_redirect(url, 500, "Request failed", opts)
+        |> halt()
+    end
+  end
+
+  def call(conn, _, _) do
+    conn
+    |> send_resp(400, Plug.Conn.Status.reason_phrase(400))
+    |> halt()
+  end
+
+  defp request(method, url, headers, hackney_opts) do
+    Logger.debug("#{__MODULE__} #{method} #{url} #{inspect(headers)}")
+    method = method |> String.downcase() |> String.to_existing_atom()
+
+    case @hackney.request(method, url, headers, "", hackney_opts) do
+      {:ok, code, headers, client} when code in @valid_resp_codes ->
+        {:ok, code, downcase_headers(headers), client}
+
+      {:ok, code, headers} when code in @valid_resp_codes ->
+        {:ok, code, downcase_headers(headers)}
+
+      {:ok, code, _, _} ->
+        {:error, {:invalid_http_response, code}}
+
+      {:error, error} ->
+        {:error, error}
+    end
+  end
+
+  defp response(conn, client, url, status, headers, opts) do
+    result =
+      conn
+      |> put_resp_headers(build_resp_headers(headers, opts))
+      |> send_chunked(status)
+      |> chunk_reply(client, opts)
+
+    case result do
+      {:ok, conn} ->
+        halt(conn)
+
+      {:error, :closed, conn} ->
+        :hackney.close(client)
+        halt(conn)
+
+      {:error, error, conn} ->
+        Logger.warn(
+          "#{__MODULE__} request to #{url} failed while reading/chunking: #{inspect(error)}"
+        )
+
+        :hackney.close(client)
+        halt(conn)
+    end
+  end
+
+  defp chunk_reply(conn, client, opts) do
+    chunk_reply(conn, client, opts, 0, 0)
+  end
+
+  defp chunk_reply(conn, client, opts, sent_so_far, duration) do
+    with {:ok, duration} <-
+           check_read_duration(
+             duration,
+             Keyword.get(opts, :max_read_duration, @max_read_duration)
+           ),
+         {:ok, data} <- @hackney.stream_body(client),
+         {:ok, duration} <- increase_read_duration(duration),
+         sent_so_far = sent_so_far + byte_size(data),
+         :ok <- body_size_constraint(sent_so_far, Keyword.get(opts, :max_body_size)),
+         {:ok, conn} <- chunk(conn, data) do
+      chunk_reply(conn, client, opts, sent_so_far, duration)
+    else
+      :done -> {:ok, conn}
+      {:error, error} -> {:error, error, conn}
+    end
+  end
+
+  defp head_response(conn, _url, code, headers, opts) do
+    conn
+    |> put_resp_headers(build_resp_headers(headers, opts))
+    |> send_resp(code, "")
+  end
+
+  defp error_or_redirect(conn, url, code, body, opts) do
+    if Keyword.get(opts, :redirect_on_failure, false) do
+      conn
+      |> Phoenix.Controller.redirect(external: url)
+      |> halt()
+    else
+      conn
+      |> send_resp(code, body)
+      |> halt
+    end
+  end
+
+  defp downcase_headers(headers) do
+    Enum.map(headers, fn {k, v} ->
+      {String.downcase(k), v}
+    end)
+  end
+
+  defp put_resp_headers(conn, headers) do
+    Enum.reduce(headers, conn, fn {k, v}, conn ->
+      put_resp_header(conn, k, v)
+    end)
+  end
+
+  defp build_req_headers(headers, opts) do
+    headers =
+      headers
+      |> downcase_headers()
+      |> Enum.filter(fn {k, _} -> k in @keep_req_headers end)
+      |> (fn headers ->
+            headers = headers ++ Keyword.get(opts, :req_headers, [])
+
+            if Keyword.get(opts, :keep_user_agent, false) do
+              List.keystore(
+                headers,
+                "user-agent",
+                0,
+                {"user-agent", Pleroma.Application.user_agent()}
+              )
+            else
+              headers
+            end
+          end).()
+  end
+
+  defp build_resp_headers(headers, opts) do
+    headers =
+      headers
+      |> Enum.filter(fn {k, _} -> k in @keep_resp_headers end)
+      |> build_resp_cache_headers(opts)
+      |> build_resp_content_disposition_header(opts)
+      |> (fn headers -> headers ++ Keyword.get(opts, :resp_headers, []) end).()
+  end
+
+  defp build_resp_cache_headers(headers, opts) do
+    has_cache? = Enum.any?(headers, fn {k, _} -> k in @resp_cache_headers end)
+
+    if has_cache? do
+      headers
+    else
+      List.keystore(headers, "cache-control", 0, {"cache-control", @default_cache_control_header})
+    end
+  end
+
+  defp build_resp_content_disposition_header(headers, opts) do
+    opt = Keyword.get(opts, :inline_content_types, @inline_content_types)
+
+    {_, content_type} =
+      List.keyfind(headers, "content-type", 0, {"content-type", "application/octect-stream"})
+
+    attachment? =
+      cond do
+        is_list(opt) && !Enum.member?(opt, content_type) -> true
+        opt == false -> true
+        true -> false
+      end
+
+    if attachment? do
+      disposition = "attachment; filename=" <> Keyword.get(opts, :attachment_name, "attachment")
+      List.keystore(headers, "content-disposition", 0, {"content-disposition", disposition})
+    else
+      headers
+    end
+  end
+
+  defp header_lenght_constraint(headers, limit) when is_integer(limit) and limit > 0 do
+    with {_, size} <- List.keyfind(headers, "content-length", 0),
+         {size, _} <- Integer.parse(size),
+         true <- size <= limit do
+      :ok
+    else
+      false ->
+        {:error, :body_too_large}
+
+      _ ->
+        :ok
+    end
+  end
+
+  defp header_lenght_constraint(_, _), do: :ok
+
+  defp body_size_constraint(size, limit) when is_integer(limit) and limit > 0 and size >= limit do
+    {:error, :body_too_large}
+  end
+
+  defp body_size_constraint(_, _), do: :ok
+
+  defp check_read_duration(duration, max)
+       when is_integer(duration) and is_integer(max) and max > 0 do
+    if duration > max do
+      {:error, :read_duration_exceeded}
+    else
+      Logger.debug("Duration #{inspect(duration)}")
+      {:ok, {duration, :erlang.system_time(:millisecond)}}
+    end
+  end
+
+  defp check_read_duration(_, _), do: {:ok, :no_duration_limit, :no_duration_limit}
+
+  defp increase_read_duration({previous_duration, started})
+       when is_integer(previous_duration) and is_integer(started) do
+    duration = :erlang.system_time(:millisecond) - started
+    {:ok, previous_duration + duration}
+  end
+
+  defp increase_read_duration(_) do
+    {:ok, :no_duration_limit, :no_duration_limit}
+  end
+end
diff --git a/lib/pleroma/upload.ex b/lib/pleroma/upload.ex
index 238630bf3..16043a264 100644
--- a/lib/pleroma/upload.ex
+++ b/lib/pleroma/upload.ex
@@ -1,81 +1,102 @@
 defmodule Pleroma.Upload do
   alias Ecto.UUID
+  require Logger
 
-  def check_file_size(path, nil), do: true
+  @type upload_option ::
+          {:dedupe, boolean()} | {:size_limit, non_neg_integer()} | {:uploader, module()}
+  @type upload_source ::
+          Plug.Upload.t() | data_uri_string() ::
+          String.t() | {:from_local, name :: String.t(), uuid :: String.t(), path :: String.t()}
 
-  def check_file_size(path, size_limit) do
-    {:ok, %{size: size}} = File.stat(path)
-    size <= size_limit
-  end
+  @spec store(upload_source, options :: [upload_option()]) :: {:ok, Map.t()} | {:error, any()}
+  def store(upload, opts \\ []) do
+    opts = get_opts(opts)
 
-  def store(file, should_dedupe, size_limit \\ nil)
-
-  def store(%Plug.Upload{} = file, should_dedupe, size_limit) do
-    content_type = get_content_type(file.path)
-
-    with uuid <- get_uuid(file, should_dedupe),
-         name <- get_name(file, uuid, content_type, should_dedupe),
-         true <- check_file_size(file.path, size_limit) do
-      strip_exif_data(content_type, file.path)
-
-      {:ok, url_path} = uploader().put_file(name, uuid, file.path, content_type, should_dedupe)
-
-      %{
-        "type" => "Document",
-        "url" => [
-          %{
-            "type" => "Link",
-            "mediaType" => content_type,
-            "href" => url_path
-          }
-        ],
-        "name" => name
-      }
+    with {:ok, name, uuid, path, content_type} <- process_upload(upload, opts),
+         _ <- strip_exif_data(content_type, path),
+         {:ok, url_spec} <- opts.uploader.put_file(name, uuid, path, content_type, opts) do
+      {:ok,
+       %{
+         "type" => "Image",
+         "url" => [
+           %{
+             "type" => "Link",
+             "mediaType" => content_type,
+             "href" => url_from_spec(url_spec)
+           }
+         ],
+         "name" => name
+       }}
     else
-      _e -> nil
-    end
-  end
-
-  def store(%{"img" => "data:image/" <> image_data}, should_dedupe, size_limit) do
-    parsed = Regex.named_captures(~r/(?<filetype>jpeg|png|gif);base64,(?<data>.*)/, image_data)
-    data = Base.decode64!(parsed["data"], ignore: :whitespace)
-
-    with tmp_path <- tempfile_for_image(data),
-         uuid <- UUID.generate(),
-         true <- check_file_size(tmp_path, size_limit) do
-      content_type = get_content_type(tmp_path)
-      strip_exif_data(content_type, tmp_path)
-
-      name =
-        create_name(
-          String.downcase(Base.encode16(:crypto.hash(:sha256, data))),
-          parsed["filetype"],
-          content_type
+      {:error, error} ->
+        Logger.error(
+          "#{__MODULE__} store (using #{inspect(opts.uploader)}) failed: #{inspect(error)}"
         )
 
-      {:ok, url_path} = uploader().put_file(name, uuid, tmp_path, content_type, should_dedupe)
-
-      %{
-        "type" => "Image",
-        "url" => [
-          %{
-            "type" => "Link",
-            "mediaType" => content_type,
-            "href" => url_path
-          }
-        ],
-        "name" => name
-      }
-    else
-      _e -> nil
+        {:error, error}
     end
   end
 
-  @doc """
-  Creates a tempfile using the Plug.Upload Genserver which cleans them up 
-  automatically.
-  """
-  def tempfile_for_image(data) do
+  defp get_opts(opts) do
+    %{
+      dedupe: Keyword.get(opts, :dedupe, Pleroma.Config.get([:instance, :dedupe_media])),
+      size_limit: Keyword.get(opts, :size_limit, Pleroma.Config.get([:instance, :upload_limit])),
+      uploader: Keyword.get(opts, :uploader, Pleroma.Config.get([__MODULE__, :uploader]))
+    }
+  end
+
+  defp process_upload(%Plug.Upload{} = file, opts) do
+    with :ok <- check_file_size(file.path, opts.size_limit),
+         uuid <- get_uuid(file, opts.dedupe),
+         content_type <- get_content_type(file.path),
+         name <- get_name(file, uuid, content_type, opts.dedupe) do
+      {:ok, name, uuid, file.path, content_type}
+    end
+  end
+
+  defp process_upload(%{"img" => "data:image/" <> image_data}, opts) do
+    parsed = Regex.named_captures(~r/(?<filetype>jpeg|png|gif);base64,(?<data>.*)/, image_data)
+    data = Base.decode64!(parsed["data"], ignore: :whitespace)
+    hash = String.downcase(Base.encode16(:crypto.hash(:sha256, data)))
+
+    with :ok <- check_binary_size(data, opts.size_limit),
+         tmp_path <- tempfile_for_image(data),
+         content_type <- get_content_type(tmp_path),
+         uuid <- UUID.generate(),
+         name <- create_name(hash, parsed["filetype"], content_type) do
+      {:ok, name, uuid, tmp_path, content_type}
+    end
+  end
+
+  # For Mix.Tasks.MigrateLocalUploads
+  defp process_upload({:from_local, name, uuid, path}, _opts) do
+    with content_type <- get_content_type(path) do
+      {:ok, name, uuid, path, content_type}
+    end
+  end
+
+  defp check_binary_size(binary, size_limit)
+       when is_integer(size_limit) and size_limit > 0 and byte_size(binary) >= size_limit do
+    {:error, :file_too_large}
+  end
+
+  defp check_binary_size(_, _), do: :ok
+
+  defp check_file_size(path, size_limit) when is_integer(size_limit) and size_limit > 0 do
+    with {:ok, %{size: size}} <- File.stat(path),
+         true <- size <= size_limit do
+      :ok
+    else
+      false -> {:error, :file_too_large}
+      error -> error
+    end
+  end
+
+  defp check_file_size(_, _), do: :ok
+
+  # Creates a tempfile using the Plug.Upload Genserver which cleans them up
+  # automatically.
+  defp tempfile_for_image(data) do
     {:ok, tmp_path} = Plug.Upload.random_file("profile_pics")
     {:ok, tmp_file} = File.open(tmp_path, [:write, :raw, :binary])
     IO.binwrite(tmp_file, data)
@@ -83,7 +104,7 @@ def tempfile_for_image(data) do
     tmp_path
   end
 
-  def strip_exif_data(content_type, file) do
+  defp strip_exif_data(content_type, file) do
     settings = Application.get_env(:pleroma, Pleroma.Upload)
     do_strip = Keyword.fetch!(settings, :strip_exif)
     [filetype, _ext] = String.split(content_type, "/")
@@ -94,16 +115,20 @@ def strip_exif_data(content_type, file) do
   end
 
   defp create_name(uuid, ext, type) do
-    case type do
-      "application/octet-stream" ->
-        String.downcase(Enum.join([uuid, ext], "."))
+    extension =
+      cond do
+        type == "application/octect-stream" -> ext
+        ext = mime_extension(ext) -> ext
+        true -> String.split(type, "/") |> List.last()
+      end
 
-      "audio/mpeg" ->
-        String.downcase(Enum.join([uuid, "mp3"], "."))
+    [uuid, extension]
+    |> Enum.join(".")
+    |> String.downcase()
+  end
 
-      _ ->
-        String.downcase(Enum.join([uuid, List.last(String.split(type, "/"))], "."))
-    end
+  defp mime_extension(type) do
+    List.first(MIME.extensions(type))
   end
 
   defp get_uuid(file, should_dedupe) do
@@ -127,11 +152,15 @@ defp get_name(file, uuid, type, should_dedupe) do
           Enum.join(parts)
         end
 
-      case type do
-        "application/octet-stream" -> file.filename
-        "audio/mpeg" -> new_filename <> ".mp3"
-        "image/jpeg" -> new_filename <> ".jpg"
-        _ -> Enum.join([new_filename, String.split(type, "/") |> List.last()], ".")
+      cond do
+        type == "application/octet-stream" ->
+          file.filename
+
+        ext = mime_extension(type) ->
+          new_filename <> "." <> ext
+
+        true ->
+          Enum.join([new_filename, String.split(type, "/") |> List.last()], ".")
       end
     end
   end
@@ -187,4 +216,13 @@ def get_content_type(file) do
   defp uploader() do
     Pleroma.Config.get!([Pleroma.Upload, :uploader])
   end
+
+  defp url_from_spec({:file, path}) do
+    [Pleroma.Web.base_url(), "media", path]
+    |> Path.join()
+  end
+
+  defp url_from_spec({:url, url}) do
+    url
+  end
 end
diff --git a/lib/pleroma/uploaders/local.ex b/lib/pleroma/uploaders/local.ex
index d96481c8d..7ca1ba07d 100644
--- a/lib/pleroma/uploaders/local.ex
+++ b/lib/pleroma/uploaders/local.ex
@@ -3,9 +3,12 @@ defmodule Pleroma.Uploaders.Local do
 
   alias Pleroma.Web
 
-  def put_file(name, uuid, tmpfile, _content_type, should_dedupe) do
-    upload_folder = get_upload_path(uuid, should_dedupe)
-    url_path = get_url(name, uuid, should_dedupe)
+  def get_file(_) do
+    {:ok, {:static_dir, upload_path()}}
+  end
+
+  def put_file(name, uuid, tmpfile, _content_type, opts) do
+    upload_folder = get_upload_path(uuid, opts.dedupe)
 
     File.mkdir_p!(upload_folder)
 
@@ -17,12 +20,11 @@ def put_file(name, uuid, tmpfile, _content_type, should_dedupe) do
       File.cp!(tmpfile, result_file)
     end
 
-    {:ok, url_path}
+    {:ok, {:file, get_url(name, uuid, opts.dedupe)}}
   end
 
   def upload_path do
-    settings = Application.get_env(:pleroma, Pleroma.Uploaders.Local)
-    Keyword.fetch!(settings, :uploads)
+    Pleroma.Config.get!([__MODULE__, :uploads])
   end
 
   defp get_upload_path(uuid, should_dedupe) do
@@ -35,17 +37,9 @@ defp get_upload_path(uuid, should_dedupe) do
 
   defp get_url(name, uuid, should_dedupe) do
     if should_dedupe do
-      url_for(:cow_uri.urlencode(name))
+      :cow_uri.urlencode(name)
     else
-      url_for(Path.join(uuid, :cow_uri.urlencode(name)))
+      Path.join(uuid, :cow_uri.urlencode(name))
     end
   end
-
-  defp url_for(file) do
-    settings = Application.get_env(:pleroma, Pleroma.Uploaders.Local)
-
-    Keyword.get(settings, :uploads_url)
-    |> String.replace("{{file}}", file)
-    |> String.replace("{{base_url}}", Web.base_url())
-  end
 end
diff --git a/lib/pleroma/uploaders/mdii.ex b/lib/pleroma/uploaders/mdii.ex
index a9d52b0dc..1d93c8154 100644
--- a/lib/pleroma/uploaders/mdii.ex
+++ b/lib/pleroma/uploaders/mdii.ex
@@ -5,7 +5,13 @@ defmodule Pleroma.Uploaders.MDII do
 
   @httpoison Application.get_env(:pleroma, :httpoison)
 
-  def put_file(name, uuid, path, content_type, should_dedupe) do
+  # MDII-hosted images are never passed through the MediaPlug; only local media.
+  # Delegate to Pleroma.Uploaders.Local
+  def get_file(file) do
+    Pleroma.Uploaders.Local.get_file(file)
+  end
+
+  def put_file(name, uuid, path, content_type, opts) do
     cgi = Pleroma.Config.get([Pleroma.Uploaders.MDII, :cgi])
     files = Pleroma.Config.get([Pleroma.Uploaders.MDII, :files])
 
@@ -18,9 +24,9 @@ def put_file(name, uuid, path, content_type, should_dedupe) do
       File.rm!(path)
       remote_file_name = String.split(body) |> List.first()
       public_url = "#{files}/#{remote_file_name}.#{extension}"
-      {:ok, public_url}
+      {:ok, {:url, public_url}}
     else
-      _ -> Pleroma.Uploaders.Local.put_file(name, uuid, path, content_type, should_dedupe)
+      _ -> Pleroma.Uploaders.Local.put_file(name, uuid, path, content_type, opts)
     end
   end
 end
diff --git a/lib/pleroma/uploaders/s3.ex b/lib/pleroma/uploaders/s3.ex
index 40a836460..2d1ddef75 100644
--- a/lib/pleroma/uploaders/s3.ex
+++ b/lib/pleroma/uploaders/s3.ex
@@ -1,40 +1,48 @@
 defmodule Pleroma.Uploaders.S3 do
-  alias Pleroma.Web.MediaProxy
-
   @behaviour Pleroma.Uploaders.Uploader
+  require Logger
 
-  def put_file(name, uuid, path, content_type, _should_dedupe) do
-    settings = Application.get_env(:pleroma, Pleroma.Uploaders.S3)
-    bucket = Keyword.fetch!(settings, :bucket)
-    public_endpoint = Keyword.fetch!(settings, :public_endpoint)
-    force_media_proxy = Keyword.fetch!(settings, :force_media_proxy)
+  # The file name is re-encoded with S3's constraints here to comply with previous links with less strict filenames
+  def get_file(file) do
+    config = Pleroma.Config.get([__MODULE__])
+
+    {:ok,
+     {:url,
+      Path.join([
+        Keyword.fetch!(config, :public_endpoint),
+        Keyword.fetch!(config, :bucket),
+        strict_encode(URI.decode(file))
+      ])}}
+  end
+
+  def put_file(name, uuid, path, content_type, _opts) do
+    config = Pleroma.Config.get([__MODULE__])
+    bucket = Keyword.get(config, :bucket)
 
     {:ok, file_data} = File.read(path)
 
     File.rm!(path)
 
-    s3_name = "#{uuid}/#{encode(name)}"
+    s3_name = "#{uuid}/#{strict_encode(name)}"
 
-    {:ok, _} =
+    op =
       ExAws.S3.put_object(bucket, s3_name, file_data, [
         {:acl, :public_read},
         {:content_type, content_type}
       ])
-      |> ExAws.request()
 
-    url_base = "#{public_endpoint}/#{bucket}/#{s3_name}"
+    case ExAws.request(op) do
+      {:ok, _} ->
+        {:ok, {:file, s3_name}}
 
-    public_url =
-      if force_media_proxy do
-        MediaProxy.url(url_base)
-      else
-        url_base
-      end
-
-    {:ok, public_url}
+      error ->
+        Logger.error("#{__MODULE__}: #{inspect(error)}")
+        {:error, "S3 Upload failed"}
+    end
   end
 
-  defp encode(name) do
-    String.replace(name, ~r/[^0-9a-zA-Z!.*'()_-]/, "-")
+  @regex Regex.compile!("[^0-9a-zA-Z!.*/'()_-]")
+  def strict_encode(name) do
+    String.replace(name, @regex, "-")
   end
 end
diff --git a/lib/pleroma/uploaders/swift/swift.ex b/lib/pleroma/uploaders/swift/swift.ex
index fa08ca966..1e865f101 100644
--- a/lib/pleroma/uploaders/swift/swift.ex
+++ b/lib/pleroma/uploaders/swift/swift.ex
@@ -14,7 +14,7 @@ def upload_file(filename, body, content_type) do
 
     case put("#{filename}", body, "X-Auth-Token": token, "Content-Type": content_type) do
       {:ok, %HTTPoison.Response{status_code: 201}} ->
-        {:ok, "#{object_url}/#{filename}"}
+        {:ok, {:file, filename}}
 
       {:ok, %HTTPoison.Response{status_code: 401}} ->
         {:error, "Unauthorized, Bad Token"}
diff --git a/lib/pleroma/uploaders/swift/uploader.ex b/lib/pleroma/uploaders/swift/uploader.ex
index 794f76cb0..5db35fe50 100644
--- a/lib/pleroma/uploaders/swift/uploader.ex
+++ b/lib/pleroma/uploaders/swift/uploader.ex
@@ -1,7 +1,11 @@
 defmodule Pleroma.Uploaders.Swift do
   @behaviour Pleroma.Uploaders.Uploader
 
-  def put_file(name, uuid, tmp_path, content_type, _should_dedupe) do
+  def get_file(name) do
+    {:ok, {:url, Path.join([Pleroma.Config.get!([__MODULE__, :object_url]), name])}}
+  end
+
+  def put_file(name, uuid, tmp_path, content_type, _opts) do
     {:ok, file_data} = File.read(tmp_path)
     remote_name = "#{uuid}/#{name}"
 
diff --git a/lib/pleroma/uploaders/uploader.ex b/lib/pleroma/uploaders/uploader.ex
index b58fc6d71..8ef82b4ef 100644
--- a/lib/pleroma/uploaders/uploader.ex
+++ b/lib/pleroma/uploaders/uploader.ex
@@ -1,20 +1,35 @@
 defmodule Pleroma.Uploaders.Uploader do
   @moduledoc """
-  Defines the contract to put an uploaded file to any backend.
+  Defines the contract to put and get an uploaded file to any backend.
   """
 
+  @doc """
+  Instructs how to get the file from the backend.
+
+  Used by `Pleroma.Plugs.UploadedMedia`.
+  """
+  @type get_method :: {:static_dir, directory :: String.t()} | {:url, url :: String.t()}
+  @callback get_file(file :: String.t()) :: {:ok, get_method()}
+
   @doc """
   Put a file to the backend.
 
-  Returns `{:ok, String.t } | {:error, String.t} containing the path of the 
-  uploaded file, or error information if the file failed to be saved to the 
-  respective backend.
+  Returns:
+
+  * `{:ok, spec}` where spec is:
+    * `{:file, filename :: String.t}` to handle reads with `get_file/1` (recommended)
+
+      This allows to correctly proxy or redirect requests to the backend, while allowing to migrate backends without breaking any URL.
+
+    * `{url, url :: String.t}` to bypass `get_file/2` and use the `url` directly in the activity.
+  * `{:error, String.t}` error information if the file failed to be saved to the backend.
+
   """
   @callback put_file(
               name :: String.t(),
               uuid :: String.t(),
               file :: File.t(),
               content_type :: String.t(),
-              should_dedupe :: Boolean.t()
-            ) :: {:ok, String.t()} | {:error, String.t()}
+              options :: Map.t()
+            ) :: {:ok, {:file, String.t()} | {:url, String.t()}} | {:error, String.t()}
 end
diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index ed579e336..76c15cf21 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -572,10 +572,8 @@ def fetch_activities_bounded(recipients_to, recipients_cc, opts \\ %{}) do
     |> Enum.reverse()
   end
 
-  def upload(file, size_limit \\ nil) do
-    with data <-
-           Upload.store(file, Application.get_env(:pleroma, :instance)[:dedupe_media], size_limit),
-         false <- is_nil(data) do
+  def upload(file, opts \\ []) do
+    with {:ok, data} <- Upload.store(file, opts) do
       Repo.insert(%Object{data: data})
     end
   end
diff --git a/lib/pleroma/web/endpoint.ex b/lib/pleroma/web/endpoint.ex
index 8728c908b..c5f9d51d9 100644
--- a/lib/pleroma/web/endpoint.ex
+++ b/lib/pleroma/web/endpoint.ex
@@ -12,7 +12,7 @@ defmodule Pleroma.Web.Endpoint do
   plug(CORSPlug)
   plug(Pleroma.Plugs.HTTPSecurityPlug)
 
-  plug(Plug.Static, at: "/media", from: Pleroma.Uploaders.Local.upload_path(), gzip: false)
+  plug(Pleroma.Plugs.UploadedMedia)
 
   plug(
     Plug.Static,
diff --git a/lib/pleroma/web/mastodon_api/mastodon_api_controller.ex b/lib/pleroma/web/mastodon_api/mastodon_api_controller.ex
index aa7e9418e..9d50d906d 100644
--- a/lib/pleroma/web/mastodon_api/mastodon_api_controller.ex
+++ b/lib/pleroma/web/mastodon_api/mastodon_api_controller.ex
@@ -60,7 +60,7 @@ def update_credentials(%{assigns: %{user: user}} = conn, params) do
     user =
       if avatar = params["avatar"] do
         with %Plug.Upload{} <- avatar,
-             {:ok, object} <- ActivityPub.upload(avatar, avatar_upload_limit),
+             {:ok, object} <- ActivityPub.upload(avatar, size_limit: avatar_upload_limit),
              change = Ecto.Changeset.change(user, %{avatar: object.data}),
              {:ok, user} = User.update_and_set_cache(change) do
           user
@@ -74,7 +74,7 @@ def update_credentials(%{assigns: %{user: user}} = conn, params) do
     user =
       if banner = params["header"] do
         with %Plug.Upload{} <- banner,
-             {:ok, object} <- ActivityPub.upload(banner, banner_upload_limit),
+             {:ok, object} <- ActivityPub.upload(banner, size_limit: banner_upload_limit),
              new_info <- Map.put(user.info, "banner", object.data),
              change <- User.info_changeset(user, %{info: new_info}),
              {:ok, user} <- User.update_and_set_cache(change) do
diff --git a/lib/pleroma/web/media_proxy/controller.ex b/lib/pleroma/web/media_proxy/controller.ex
index bb257c262..324f75263 100644
--- a/lib/pleroma/web/media_proxy/controller.ex
+++ b/lib/pleroma/web/media_proxy/controller.ex
@@ -1,135 +1,32 @@
 defmodule Pleroma.Web.MediaProxy.MediaProxyController do
   use Pleroma.Web, :controller
-  require Logger
+  alias Pleroma.{Web.MediaProxy, ReverseProxy}
 
-  @httpoison Application.get_env(:pleroma, :httpoison)
-
-  @max_body_length 25 * 1_048_576
-
-  @cache_control %{
-    default: "public, max-age=1209600",
-    error: "public, must-revalidate, max-age=160"
-  }
-
-  # Content-types that will not be returned as content-disposition attachments
-  # Override with :media_proxy, :safe_content_types in the configuration
-  @safe_content_types [
-    "image/gif",
-    "image/jpeg",
-    "image/jpg",
-    "image/png",
-    "image/svg+xml",
-    "audio/mpeg",
-    "audio/mp3",
-    "video/webm",
-    "video/mp4"
-  ]
-
-  def remote(conn, params = %{"sig" => sig, "url" => url}) do
-    config = Application.get_env(:pleroma, :media_proxy, [])
-
-    with true <- Keyword.get(config, :enabled, false),
-         {:ok, url} <- Pleroma.Web.MediaProxy.decode_url(sig, url),
+  def remote(conn, params = %{"sig" => sig64, "url" => url64}) do
+    with config <- Pleroma.Config.get([:media_proxy]),
+         true <- Keyword.get(config, :enabled, false),
+         {:ok, url} <- MediaProxy.decode_url(sig64, url64),
          filename <- Path.basename(URI.parse(url).path),
-         true <-
-           if(Map.get(params, "filename"),
-             do: filename == Path.basename(conn.request_path),
-             else: true
-           ),
-         {:ok, content_type, body} <- proxy_request(url),
-         safe_content_type <-
-           Enum.member?(
-             Keyword.get(config, :safe_content_types, @safe_content_types),
-             content_type
-           ) do
-      conn
-      |> put_resp_content_type(content_type)
-      |> set_cache_header(:default)
-      |> put_resp_header(
-        "content-security-policy",
-        "default-src 'none'; style-src 'unsafe-inline'; media-src data:; img-src 'self' data:"
-      )
-      |> put_resp_header("x-xss-protection", "1; mode=block")
-      |> put_resp_header("x-content-type-options", "nosniff")
-      |> put_attachement_header(safe_content_type, filename)
-      |> send_resp(200, body)
+         :ok <- filename_matches(Map.has_key?(params, "filename"), conn.request_path, url) do
+      ReverseProxy.call(conn, url, Keyword.get(config, :proxy_opts, []))
     else
       false ->
-        send_error(conn, 404)
+        send_resp(conn, 404, Plug.Conn.Status.reason_phrase(404))
 
       {:error, :invalid_signature} ->
-        send_error(conn, 403)
+        send_resp(conn, 403, Plug.Conn.Status.reason_phrase(403))
 
-      {:error, {:http, _, url}} ->
-        redirect_or_error(conn, url, Keyword.get(config, :redirect_on_failure, true))
+      {:wrong_filename, filename} ->
+        redirect(conn, external: MediaProxy.build_url(sig64, url64, filename))
     end
   end
 
-  defp proxy_request(link) do
-    headers = [
-      {"user-agent",
-       "Pleroma/MediaProxy; #{Pleroma.Web.base_url()} <#{
-         Application.get_env(:pleroma, :instance)[:email]
-       }>"}
-    ]
+  def filename_matches(has_filename, path, url) do
+    filename = MediaProxy.filename(url)
 
-    options =
-      @httpoison.process_request_options([:insecure, {:follow_redirect, true}]) ++
-        [{:pool, :default}]
-
-    with {:ok, 200, headers, client} <- :hackney.request(:get, link, headers, "", options),
-         headers = Enum.into(headers, Map.new()),
-         {:ok, body} <- proxy_request_body(client),
-         content_type <- proxy_request_content_type(headers, body) do
-      {:ok, content_type, body}
-    else
-      {:ok, status, _, _} ->
-        Logger.warn("MediaProxy: request failed, status #{status}, link: #{link}")
-        {:error, {:http, :bad_status, link}}
-
-      {:error, error} ->
-        Logger.warn("MediaProxy: request failed, error #{inspect(error)}, link: #{link}")
-        {:error, {:http, error, link}}
+    cond do
+      has_filename && filename && Path.basename(path) != filename -> {:wrong_filename, filename}
+      true -> :ok
     end
   end
-
-  defp set_cache_header(conn, key) do
-    Plug.Conn.put_resp_header(conn, "cache-control", @cache_control[key])
-  end
-
-  defp redirect_or_error(conn, url, true), do: redirect(conn, external: url)
-  defp redirect_or_error(conn, url, _), do: send_error(conn, 502, "Media proxy error: " <> url)
-
-  defp send_error(conn, code, body \\ "") do
-    conn
-    |> set_cache_header(:error)
-    |> send_resp(code, body)
-  end
-
-  defp proxy_request_body(client), do: proxy_request_body(client, <<>>)
-
-  defp proxy_request_body(client, body) when byte_size(body) < @max_body_length do
-    case :hackney.stream_body(client) do
-      {:ok, data} -> proxy_request_body(client, <<body::binary, data::binary>>)
-      :done -> {:ok, body}
-      {:error, reason} -> {:error, reason}
-    end
-  end
-
-  defp proxy_request_body(client, _) do
-    :hackney.close(client)
-    {:error, :body_too_large}
-  end
-
-  # TODO: the body is passed here as well because some hosts do not provide a content-type.
-  # At some point we may want to use magic numbers to discover the content-type and reply a proper one.
-  defp proxy_request_content_type(headers, _body) do
-    headers["Content-Type"] || headers["content-type"] || "application/octet-stream"
-  end
-
-  defp put_attachement_header(conn, true, _), do: conn
-
-  defp put_attachement_header(conn, false, filename) do
-    put_resp_header(conn, "content-disposition", "attachment; filename='#{filename}'")
-  end
 end
diff --git a/lib/pleroma/web/media_proxy/media_proxy.ex b/lib/pleroma/web/media_proxy/media_proxy.ex
index 0fc0a07b2..28aacb0b1 100644
--- a/lib/pleroma/web/media_proxy/media_proxy.ex
+++ b/lib/pleroma/web/media_proxy/media_proxy.ex
@@ -17,10 +17,8 @@ def url(url) do
       base64 = Base.url_encode64(url, @base64_opts)
       sig = :crypto.hmac(:sha, secret, base64)
       sig64 = sig |> Base.url_encode64(@base64_opts)
-      filename = if path = URI.parse(url).path, do: "/" <> Path.basename(path), else: ""
 
-      Keyword.get(config, :base_url, Pleroma.Web.base_url()) <>
-        "/proxy/#{sig64}/#{base64}#{filename}"
+      build_url(sig64, base64, filename(url))
     end
   end
 
@@ -35,4 +33,20 @@ def decode_url(sig, url) do
       {:error, :invalid_signature}
     end
   end
+
+  def filename(url_or_path) do
+    if path = URI.parse(url_or_path).path, do: Path.basename(path)
+  end
+
+  def build_url(sig_base64, url_base64, filename \\ nil) do
+    [
+      Pleroma.Config.get([:media_proxy, :base_url], Pleroma.Web.base_url()),
+      "proxy",
+      sig_base64,
+      url_base64,
+      filename
+    ]
+    |> Enum.filter(fn value -> value end)
+    |> Path.join()
+  end
 end
diff --git a/lib/pleroma/web/twitter_api/twitter_api.ex b/lib/pleroma/web/twitter_api/twitter_api.ex
index 5bfb83b1e..6223580e1 100644
--- a/lib/pleroma/web/twitter_api/twitter_api.ex
+++ b/lib/pleroma/web/twitter_api/twitter_api.ex
@@ -97,7 +97,7 @@ def upload(%Plug.Upload{} = file, format \\ "xml") do
     {:ok, object} = ActivityPub.upload(file)
 
     url = List.first(object.data["url"])
-    href = url["href"] |> MediaProxy.url()
+    href = url["href"]
     type = url["mediaType"]
 
     case format do
diff --git a/lib/pleroma/web/twitter_api/twitter_api_controller.ex b/lib/pleroma/web/twitter_api/twitter_api_controller.ex
index cd0e2121c..fa9ee9f99 100644
--- a/lib/pleroma/web/twitter_api/twitter_api_controller.ex
+++ b/lib/pleroma/web/twitter_api/twitter_api_controller.ex
@@ -294,7 +294,7 @@ def update_avatar(%{assigns: %{user: user}} = conn, params) do
       Application.get_env(:pleroma, :instance)
       |> Keyword.fetch(:avatar_upload_limit)
 
-    {:ok, object} = ActivityPub.upload(params, upload_limit)
+    {:ok, object} = ActivityPub.upload(params, size_limit: upload_limit)
     change = Changeset.change(user, %{avatar: object.data})
     {:ok, user} = User.update_and_set_cache(change)
     CommonAPI.update(user)
@@ -307,7 +307,8 @@ def update_banner(%{assigns: %{user: user}} = conn, params) do
       Application.get_env(:pleroma, :instance)
       |> Keyword.fetch(:banner_upload_limit)
 
-    with {:ok, object} <- ActivityPub.upload(%{"img" => params["banner"]}, upload_limit),
+    with {:ok, object} <-
+           ActivityPub.upload(%{"img" => params["banner"]}, size_limit: upload_limit),
          new_info <- Map.put(user.info, "banner", object.data),
          change <- User.info_changeset(user, %{info: new_info}),
          {:ok, user} <- User.update_and_set_cache(change) do
@@ -325,7 +326,7 @@ def update_background(%{assigns: %{user: user}} = conn, params) do
       Application.get_env(:pleroma, :instance)
       |> Keyword.fetch(:background_upload_limit)
 
-    with {:ok, object} <- ActivityPub.upload(params, upload_limit),
+    with {:ok, object} <- ActivityPub.upload(params, size_limit: upload_limit),
          new_info <- Map.put(user.info, "background", object.data),
          change <- User.info_changeset(user, %{info: new_info}),
          {:ok, _user} <- User.update_and_set_cache(change) do
diff --git a/test/support/httpoison_mock.ex b/test/support/httpoison_mock.ex
index 0be09b6ce..e7344500f 100644
--- a/test/support/httpoison_mock.ex
+++ b/test/support/httpoison_mock.ex
@@ -1,6 +1,8 @@
 defmodule HTTPoisonMock do
   alias HTTPoison.Response
 
+  def process_request_options(options), do: options
+
   def get(url, body \\ [], headers \\ [])
 
   def get("https://prismo.news/@mxb", _, _) do
diff --git a/test/upload_test.exs b/test/upload_test.exs
index d273ea5f6..998245b29 100644
--- a/test/upload_test.exs
+++ b/test/upload_test.exs
@@ -2,7 +2,35 @@ defmodule Pleroma.UploadTest do
   alias Pleroma.Upload
   use Pleroma.DataCase
 
-  describe "Storing a file" do
+  describe "Storing a file with the Local uploader" do
+    setup do
+      uploader = Pleroma.Config.get([Pleroma.Upload, :uploader])
+
+      unless uploader == Pleroma.Uploaders.Local do
+        on_exit(fn ->
+          Pleroma.Config.put([Pleroma.Upload, :uploader], uploader)
+        end)
+      end
+
+      :ok
+    end
+
+    test "returns a media url" do
+      File.cp!("test/fixtures/image.jpg", "test/fixtures/image_tmp.jpg")
+
+      file = %Plug.Upload{
+        content_type: "image/jpg",
+        path: Path.absname("test/fixtures/image_tmp.jpg"),
+        filename: "image.jpg"
+      }
+
+      {:ok, data} = Upload.store(file)
+
+      assert %{"url" => [%{"href" => url}]} = data
+
+      assert String.starts_with?(url, Pleroma.Web.base_url() <> "/media/")
+    end
+
     test "copies the file to the configured folder with deduping" do
       File.cp!("test/fixtures/image.jpg", "test/fixtures/image_tmp.jpg")
 
@@ -12,7 +40,7 @@ test "copies the file to the configured folder with deduping" do
         filename: "an [image.jpg"
       }
 
-      data = Upload.store(file, true)
+      {:ok, data} = Upload.store(file, dedupe: true)
 
       assert data["name"] ==
                "e7a6d0cf595bff76f14c9a98b6c199539559e8b844e02e51e5efcfd1f614a2df.jpeg"
@@ -27,7 +55,7 @@ test "copies the file to the configured folder without deduping" do
         filename: "an [image.jpg"
       }
 
-      data = Upload.store(file, false)
+      {:ok, data} = Upload.store(file, dedupe: false)
       assert data["name"] == "an [image.jpg"
     end
 
@@ -40,7 +68,7 @@ test "fixes incorrect content type" do
         filename: "an [image.jpg"
       }
 
-      data = Upload.store(file, true)
+      {:ok, data} = Upload.store(file, dedupe: true)
       assert hd(data["url"])["mediaType"] == "image/jpeg"
     end
 
@@ -53,7 +81,7 @@ test "adds missing extension" do
         filename: "an [image"
       }
 
-      data = Upload.store(file, false)
+      {:ok, data} = Upload.store(file, dedupe: false)
       assert data["name"] == "an [image.jpg"
     end
 
@@ -66,7 +94,7 @@ test "fixes incorrect file extension" do
         filename: "an [image.blah"
       }
 
-      data = Upload.store(file, false)
+      {:ok, data} = Upload.store(file, dedupe: false)
       assert data["name"] == "an [image.jpg"
     end
 
@@ -79,7 +107,7 @@ test "don't modify filename of an unknown type" do
         filename: "test.txt"
       }
 
-      data = Upload.store(file, false)
+      {:ok, data} = Upload.store(file, dedupe: false)
       assert data["name"] == "test.txt"
     end
   end