Merge branch 'develop' into issue/2099

46 files changed, 2487 insertions, 181 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5abafdf69..e61b1d144 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## Unreleased
 
+### Added
+- Experimental websocket-based federation between Pleroma instances.
+
 ### Changed
 
 - Renamed `:await_up_timeout` in `:connections_pool` namespace to `:connect_timeout`, old name is deprecated.
@@ -13,6 +16,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Users with the `discoverable` field set to false will not show up in searches.
 - Minimum lifetime for ephmeral activities changed to 10 minutes and made configurable (`:min_lifetime` option).
 
+### Added
+- Media preview proxy (requires media proxy be enabled; see `:media_preview_proxy` config for more details).
+- Pleroma API: Importing the mutes users from CSV files.
+
 ### Removed
 
 - **Breaking:** `Pleroma.Workers.Cron.StatsWorker` setting from Oban `:crontab` (moved to a simpler implementation).
@@ -21,8 +28,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Removed `:managed_config` option. In practice, it was accidentally removed with 2.0.0 release when frontends were
 switched to a new configuration mechanism, however it was not officially removed until now.
 
-### Added
-- Pleroma API: Importing the mutes users from CSV files.
 
 ## [2.1.2] - 2020-09-17
 
diff --git a/config/config.exs b/config/config.exs
index c204814d0..00624bf00 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -130,6 +130,7 @@ config :pleroma, Pleroma.Web.Endpoint,
     dispatch: [
       {:_,
        [
+         {"/api/fedsocket/v1", Pleroma.Web.FedSockets.IncomingHandler, []},
          {"/api/v1/streaming", Pleroma.Web.MastodonAPI.WebsocketHandler, []},
          {"/websocket", Phoenix.Endpoint.CowboyWebSocket,
           {Phoenix.Transports.WebSocket,
@@ -148,6 +149,16 @@ config :pleroma, Pleroma.Web.Endpoint,
     "SameSite=Lax"
   ]
 
+config :pleroma, :fed_sockets,
+  enabled: false,
+  connection_duration: :timer.hours(8),
+  rejection_duration: :timer.minutes(15),
+  fed_socket_fetches: [
+    default: 12_000,
+    interval: 3_000,
+    lazy: false
+  ]
+
 # Configures Elixir's Logger
 config :logger, :console,
   level: :debug,
@@ -423,6 +434,8 @@ config :pleroma, :media_proxy,
   proxy_opts: [
     redirect_on_failure: false,
     max_body_length: 25 * 1_048_576,
+    # Note: max_read_duration defaults to Pleroma.ReverseProxy.max_read_duration_default/1
+    max_read_duration: 30_000,
     http: [
       follow_redirect: true,
       pool: :media
@@ -437,6 +450,14 @@ config :pleroma, Pleroma.Web.MediaProxy.Invalidation.Http,
 
 config :pleroma, Pleroma.Web.MediaProxy.Invalidation.Script, script_path: nil
 
+# Note: media preview proxy depends on media proxy to be enabled
+config :pleroma, :media_preview_proxy,
+  enabled: false,
+  thumbnail_max_width: 600,
+  thumbnail_max_height: 600,
+  image_quality: 85,
+  min_content_length: 100 * 1024
+
 config :pleroma, :chat, enabled: true
 
 config :phoenix, :format_encoders, json: Jason
@@ -532,6 +553,7 @@ config :pleroma, Oban,
     token_expiration: 5,
     federator_incoming: 50,
     federator_outgoing: 50,
+    ingestion_queue: 50,
     web_push: 50,
     mailer: 10,
     transmogrifier: 20,
@@ -741,8 +763,8 @@ config :pleroma, :pools,
   ],
   media: [
     size: 50,
-    max_waiting: 10,
-    recv_timeout: 10_000
+    max_waiting: 20,
+    recv_timeout: 15_000
   ],
   upload: [
     size: 25,
@@ -787,6 +809,8 @@ config :tzdata, :http_client, Pleroma.HTTP.Tzdata
 
 config :ex_aws, http_client: Pleroma.HTTP.ExAws
 
+config :web_push_encryption, http_client: Pleroma.HTTP
+
 config :pleroma, :instances_favicons, enabled: false
 
 config :floki, :html_parser, Floki.HTMLParser.FastHtml
diff --git a/config/description.exs b/config/description.exs
index 2b30f8148..097e98633 100644
--- a/config/description.exs
+++ b/config/description.exs
@@ -272,6 +272,19 @@ config :pleroma, :config_description, [
   },
   %{
     group: :pleroma,
+    key: :fed_sockets,
+    type: :group,
+    description: "Websocket based federation",
+    children: [
+      %{
+        key: :enabled,
+        type: :boolean,
+        description: "Enable FedSockets"
+      }
+    ]
+  },
+  %{
+    group: :pleroma,
     key: Pleroma.Emails.Mailer,
     type: :group,
     description: "Mailer-related settings",
@@ -1874,6 +1887,7 @@ config :pleroma, :config_description, [
         suggestions: [
           redirect_on_failure: false,
           max_body_length: 25 * 1_048_576,
+          max_read_duration: 30_000,
           http: [
             follow_redirect: true,
             pool: :media
@@ -1895,6 +1909,11 @@ config :pleroma, :config_description, [
                 "specified length. It is validated with the `content-length` header and also verified when proxying."
           },
           %{
+            key: :max_read_duration,
+            type: :integer,
+            description: "Timeout (in milliseconds) of GET request to remote URI."
+          },
+          %{
             key: :http,
             label: "HTTP",
             type: :keyword,
@@ -1942,6 +1961,43 @@ config :pleroma, :config_description, [
   },
   %{
     group: :pleroma,
+    key: :media_preview_proxy,
+    type: :group,
+    description: "Media preview proxy",
+    children: [
+      %{
+        key: :enabled,
+        type: :boolean,
+        description:
+          "Enables proxying of remote media preview to the instance's proxy. Requires enabled media proxy."
+      },
+      %{
+        key: :thumbnail_max_width,
+        type: :integer,
+        description:
+          "Max width of preview thumbnail for images (video preview always has original dimensions)."
+      },
+      %{
+        key: :thumbnail_max_height,
+        type: :integer,
+        description:
+          "Max height of preview thumbnail for images (video preview always has original dimensions)."
+      },
+      %{
+        key: :image_quality,
+        type: :integer,
+        description: "Quality of the output. Ranges from 0 (min quality) to 100 (max quality)."
+      },
+      %{
+        key: :min_content_length,
+        type: :integer,
+        description:
+          "Min content length to perform preview, in bytes. If greater than 0, media smaller in size will be served as is, without thumbnailing."
+      }
+    ]
+  },
+  %{
+    group: :pleroma,
     key: Pleroma.Web.MediaProxy.Invalidation.Http,
     type: :group,
     description: "HTTP invalidate settings",
diff --git a/config/test.exs b/config/test.exs
index 0ee6f1b7f..93a0e2a61 100644
--- a/config/test.exs
+++ b/config/test.exs
@@ -19,6 +19,11 @@ config :logger, :console,
   level: :warn,
   format: "\n[$level] $message\n"
 
+config :pleroma, :fed_sockets,
+  enabled: false,
+  connection_duration: 5,
+  rejection_duration: 5
+
 config :pleroma, :auth, oauth_consumer_strategies: []
 
 config :pleroma, Pleroma.Upload,
diff --git a/docs/configuration/cheatsheet.md b/docs/configuration/cheatsheet.md
index 054b8fe43..42e5fe808 100644
--- a/docs/configuration/cheatsheet.md
+++ b/docs/configuration/cheatsheet.md
@@ -225,6 +225,16 @@ Enables the worker which processes posts scheduled for deletion. Pinned posts ar
 
 * `enabled`: whether expired activities will be sent to the job queue to be deleted
 
+## FedSockets
+FedSockets is an experimental feature allowing for Pleroma backends to federate using a persistant websocket connection as opposed to making each federation a seperate http connection. This feature is currently off by default. It is configurable throught he following options.
+
+### :fedsockets
+* `enabled`: Enables FedSockets for this instance. `false` by default.
+* `connection_duration`: Time an idle websocket is kept open.
+* `rejection_duration`: Failures to connect via FedSockets will not be retried for this period of time.
+* `fed_socket_fetches` and `fed_socket_rejections`: Settings passed to `cachex` for the fetch registry, and rejection stacks. See `Pleroma.Web.FedSockets` for more details.
+
+
 ## Frontends
 
 ### :frontend_configurations
@@ -314,6 +324,14 @@ This section describe PWA manifest instance-specific values. Currently this opti
   * `enabled`: Enables purge cache
   * `provider`: Which one of  the [purge cache strategy](#purge-cache-strategy) to use.
 
+## :media_preview_proxy
+
+* `enabled`: Enables proxying of remote media preview to the instance’s proxy. Requires enabled media proxy (`media_proxy/enabled`).
+* `thumbnail_max_width`: Max width of preview thumbnail for images (video preview always has original dimensions).
+* `thumbnail_max_height`: Max height of preview thumbnail for images (video preview always has original dimensions).
+* `image_quality`: Quality of the output. Ranges from 0 (min quality) to 100 (max quality).
+* `min_content_length`: Min content length to perform preview, in bytes. If greater than 0, media smaller in size will be served as is, without thumbnailing.
+
 ### Purge cache strategy
 
 #### Pleroma.Web.MediaProxy.Invalidation.Script
diff --git a/lib/pleroma/application.ex b/lib/pleroma/application.ex
index c39e24919..00ec79a2a 100644
--- a/lib/pleroma/application.ex
+++ b/lib/pleroma/application.ex
@@ -99,7 +99,7 @@ defmodule Pleroma.Application do
           {Oban, Config.get(Oban)}
         ] ++
         task_children(@env) ++
-        streamer_child(@env) ++
+        dont_run_in_test(@env) ++
         chat_child(@env, chat_enabled?()) ++
         [
           Pleroma.Web.Endpoint,
@@ -188,16 +188,17 @@ defmodule Pleroma.Application do
 
   defp chat_enabled?, do: Config.get([:chat, :enabled])
 
-  defp streamer_child(env) when env in [:test, :benchmark], do: []
+  defp dont_run_in_test(env) when env in [:test, :benchmark], do: []
 
-  defp streamer_child(_) do
+  defp dont_run_in_test(_) do
     [
       {Registry,
        [
          name: Pleroma.Web.Streamer.registry(),
          keys: :duplicate,
          partitions: System.schedulers_online()
-       ]}
+       ]},
+      Pleroma.Web.FedSockets.Supervisor
     ]
   end
 
diff --git a/lib/pleroma/helpers/media_helper.ex b/lib/pleroma/helpers/media_helper.ex
new file mode 100644
index 000000000..b6f35a24b
--- /dev/null
+++ b/lib/pleroma/helpers/media_helper.ex
@@ -0,0 +1,150 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Helpers.MediaHelper do
+  @moduledoc """
+  Handles common media-related operations.
+  """
+
+  alias Pleroma.HTTP
+
+  def image_resize(url, options) do
+    with executable when is_binary(executable) <- System.find_executable("convert"),
+         {:ok, args} <- prepare_image_resize_args(options),
+         {:ok, env} <- HTTP.get(url, [], pool: :media),
+         {:ok, fifo_path} <- mkfifo() do
+      args = List.flatten([fifo_path, args])
+      run_fifo(fifo_path, env, executable, args)
+    else
+      nil -> {:error, {:convert, :command_not_found}}
+      {:error, _} = error -> error
+    end
+  end
+
+  defp prepare_image_resize_args(
+         %{max_width: max_width, max_height: max_height, format: "png"} = options
+       ) do
+    quality = options[:quality] || 85
+    resize = Enum.join([max_width, "x", max_height, ">"])
+
+    args = [
+      "-resize",
+      resize,
+      "-quality",
+      to_string(quality),
+      "png:-"
+    ]
+
+    {:ok, args}
+  end
+
+  defp prepare_image_resize_args(%{max_width: max_width, max_height: max_height} = options) do
+    quality = options[:quality] || 85
+    resize = Enum.join([max_width, "x", max_height, ">"])
+
+    args = [
+      "-interlace",
+      "Plane",
+      "-resize",
+      resize,
+      "-quality",
+      to_string(quality),
+      "jpg:-"
+    ]
+
+    {:ok, args}
+  end
+
+  defp prepare_image_resize_args(_), do: {:error, :missing_options}
+
+  # Note: video thumbnail is intentionally not resized (always has original dimensions)
+  def video_framegrab(url) do
+    with executable when is_binary(executable) <- System.find_executable("ffmpeg"),
+         {:ok, env} <- HTTP.get(url, [], pool: :media),
+         {:ok, fifo_path} <- mkfifo(),
+         args = [
+           "-y",
+           "-i",
+           fifo_path,
+           "-vframes",
+           "1",
+           "-f",
+           "mjpeg",
+           "-loglevel",
+           "error",
+           "-"
+         ] do
+      run_fifo(fifo_path, env, executable, args)
+    else
+      nil -> {:error, {:ffmpeg, :command_not_found}}
+      {:error, _} = error -> error
+    end
+  end
+
+  defp run_fifo(fifo_path, env, executable, args) do
+    pid =
+      Port.open({:spawn_executable, executable}, [
+        :use_stdio,
+        :stream,
+        :exit_status,
+        :binary,
+        args: args
+      ])
+
+    fifo = Port.open(to_charlist(fifo_path), [:eof, :binary, :stream, :out])
+    fix = Pleroma.Helpers.QtFastStart.fix(env.body)
+    true = Port.command(fifo, fix)
+    :erlang.port_close(fifo)
+    loop_recv(pid)
+  after
+    File.rm(fifo_path)
+  end
+
+  defp mkfifo do
+    path = Path.join(System.tmp_dir!(), "pleroma-media-preview-pipe-#{Ecto.UUID.generate()}")
+
+    case System.cmd("mkfifo", [path]) do
+      {_, 0} ->
+        spawn(fifo_guard(path))
+        {:ok, path}
+
+      {_, err} ->
+        {:error, {:fifo_failed, err}}
+    end
+  end
+
+  defp fifo_guard(path) do
+    pid = self()
+
+    fn ->
+      ref = Process.monitor(pid)
+
+      receive do
+        {:DOWN, ^ref, :process, ^pid, _} ->
+          File.rm(path)
+      end
+    end
+  end
+
+  defp loop_recv(pid) do
+    loop_recv(pid, <<>>)
+  end
+
+  defp loop_recv(pid, acc) do
+    receive do
+      {^pid, {:data, data}} ->
+        loop_recv(pid, acc <> data)
+
+      {^pid, {:exit_status, 0}} ->
+        {:ok, acc}
+
+      {^pid, {:exit_status, status}} ->
+        {:error, status}
+    after
+      5000 ->
+        :erlang.port_close(pid)
+        {:error, :timeout}
+    end
+  end
+end
diff --git a/lib/pleroma/helpers/qt_fast_start.ex b/lib/pleroma/helpers/qt_fast_start.ex
new file mode 100644
index 000000000..bb93224b5
--- /dev/null
+++ b/lib/pleroma/helpers/qt_fast_start.ex
@@ -0,0 +1,131 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Helpers.QtFastStart do
+  @moduledoc """
+  (WIP) Converts a "slow start" (data before metadatas) mov/mp4 file to a "fast start" one (metadatas before data).
+  """
+
+  # TODO: Cleanup and optimizations
+  # Inspirations: https://www.ffmpeg.org/doxygen/3.4/qt-faststart_8c_source.html
+  #               https://github.com/danielgtaylor/qtfaststart/blob/master/qtfaststart/processor.py
+  #               ISO/IEC 14496-12:2015, ISO/IEC 15444-12:2015
+  #               Paracetamol
+
+  def fix(<<0x00, 0x00, 0x00, _, 0x66, 0x74, 0x79, 0x70, _::bits>> = binary) do
+    index = fix(binary, 0, nil, nil, [])
+
+    case index do
+      :abort -> binary
+      [{"ftyp", _, _, _, _}, {"mdat", _, _, _, _} | _] -> faststart(index)
+      [{"ftyp", _, _, _, _}, {"free", _, _, _, _}, {"mdat", _, _, _, _} | _] -> faststart(index)
+      _ -> binary
+    end
+  end
+
+  def fix(binary) do
+    binary
+  end
+
+  # MOOV have been seen before MDAT- abort
+  defp fix(<<_::bits>>, _, true, false, _) do
+    :abort
+  end
+
+  defp fix(
+         <<size::integer-big-size(32), fourcc::bits-size(32), rest::bits>>,
+         pos,
+         got_moov,
+         got_mdat,
+         acc
+       ) do
+    full_size = (size - 8) * 8
+    <<data::bits-size(full_size), rest::bits>> = rest
+
+    acc = [
+      {fourcc, pos, pos + size, size,
+       <<size::integer-big-size(32), fourcc::bits-size(32), data::bits>>}
+      | acc
+    ]
+
+    fix(rest, pos + size, got_moov || fourcc == "moov", got_mdat || fourcc == "mdat", acc)
+  end
+
+  defp fix(<<>>, _pos, _, _, acc) do
+    :lists.reverse(acc)
+  end
+
+  defp faststart(index) do
+    {{_ftyp, _, _, _, ftyp}, index} = List.keytake(index, "ftyp", 0)
+
+    # Skip re-writing the free fourcc as it's kind of useless.
+    # Why stream useless bytes when you can do without?
+    {free_size, index} =
+      case List.keytake(index, "free", 0) do
+        {{_, _, _, size, _}, index} -> {size, index}
+        _ -> {0, index}
+      end
+
+    {{_moov, _, _, moov_size, moov}, index} = List.keytake(index, "moov", 0)
+    offset = -free_size + moov_size
+    rest = for {_, _, _, _, data} <- index, do: data, into: []
+    <<moov_head::bits-size(64), moov_data::bits>> = moov
+    [ftyp, moov_head, fix_moov(moov_data, offset, []), rest]
+  end
+
+  defp fix_moov(
+         <<size::integer-big-size(32), fourcc::bits-size(32), rest::bits>>,
+         offset,
+         acc
+       ) do
+    full_size = (size - 8) * 8
+    <<data::bits-size(full_size), rest::bits>> = rest
+
+    data =
+      cond do
+        fourcc in ["trak", "mdia", "minf", "stbl"] ->
+          # Theses contains sto or co64 part
+          [<<size::integer-big-size(32), fourcc::bits-size(32)>>, fix_moov(data, offset, [])]
+
+        fourcc in ["stco", "co64"] ->
+          # fix the damn thing
+          <<version::integer-big-size(32), count::integer-big-size(32), rest::bits>> = data
+
+          entry_size =
+            case fourcc do
+              "stco" -> 32
+              "co64" -> 64
+            end
+
+          [
+            <<size::integer-big-size(32), fourcc::bits-size(32), version::integer-big-size(32),
+              count::integer-big-size(32)>>,
+            rewrite_entries(entry_size, offset, rest, [])
+          ]
+
+        true ->
+          [<<size::integer-big-size(32), fourcc::bits-size(32)>>, data]
+      end
+
+    acc = [acc | data]
+    fix_moov(rest, offset, acc)
+  end
+
+  defp fix_moov(<<>>, _, acc), do: acc
+
+  for size <- [32, 64] do
+    defp rewrite_entries(
+           unquote(size),
+           offset,
+           <<pos::integer-big-size(unquote(size)), rest::bits>>,
+           acc
+         ) do
+      rewrite_entries(unquote(size), offset, rest, [
+        acc | <<pos + offset::integer-big-size(unquote(size))>>
+      ])
+    end
+  end
+
+  defp rewrite_entries(_, _, <<>>, acc), do: acc
+end
diff --git a/lib/pleroma/helpers/uri_helper.ex b/lib/pleroma/helpers/uri_helper.ex
index 6d205a636..f1301f055 100644
--- a/lib/pleroma/helpers/uri_helper.ex
+++ b/lib/pleroma/helpers/uri_helper.ex
@@ -3,18 +3,22 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Helpers.UriHelper do
-  def append_uri_params(uri, appended_params) do
+  def modify_uri_params(uri, overridden_params, deleted_params \\ []) do
     uri = URI.parse(uri)
-    appended_params = for {k, v} <- appended_params, into: %{}, do: {to_string(k), v}
-    existing_params = URI.query_decoder(uri.query || "") |> Enum.into(%{})
-    updated_params_keys = Enum.uniq(Map.keys(existing_params) ++ Map.keys(appended_params))
+
+    existing_params = URI.query_decoder(uri.query || "") |> Map.new()
+    overridden_params = Map.new(overridden_params, fn {k, v} -> {to_string(k), v} end)
+    deleted_params = Enum.map(deleted_params, &to_string/1)
 
     updated_params =
-      for k <- updated_params_keys, do: {k, appended_params[k] || existing_params[k]}
+      existing_params
+      |> Map.merge(overridden_params)
+      |> Map.drop(deleted_params)
 
     uri
     |> Map.put(:query, URI.encode_query(updated_params))
     |> URI.to_string()
+    |> String.replace_suffix("?", "")
   end
 
   def maybe_add_base("/" <> uri, base), do: Path.join([base, uri])
diff --git a/lib/pleroma/instances/instance.ex b/lib/pleroma/instances/instance.ex
index 6948651c7..f0f601469 100644
--- a/lib/pleroma/instances/instance.ex
+++ b/lib/pleroma/instances/instance.ex
@@ -156,9 +156,7 @@ defmodule Pleroma.Instances.Instance do
   defp scrape_favicon(%URI{} = instance_uri) do
     try do
       with {:ok, %Tesla.Env{body: html}} <-
-             Pleroma.HTTP.get(to_string(instance_uri), [{"accept", "text/html"}],
-               adapter: [pool: :media]
-             ),
+             Pleroma.HTTP.get(to_string(instance_uri), [{"accept", "text/html"}], pool: :media),
            {_, [favicon_rel | _]} when is_binary(favicon_rel) <-
              {:parse,
               html |> Floki.parse_document!() |> Floki.attribute("link[rel=icon]", "href")},
diff --git a/lib/pleroma/object/fetcher.ex b/lib/pleroma/object/fetcher.ex
index 24dc7cb95..169298b34 100644
--- a/lib/pleroma/object/fetcher.ex
+++ b/lib/pleroma/object/fetcher.ex
@@ -12,6 +12,7 @@ defmodule Pleroma.Object.Fetcher do
   alias Pleroma.Web.ActivityPub.ObjectValidator
   alias Pleroma.Web.ActivityPub.Transmogrifier
   alias Pleroma.Web.Federator
+  alias Pleroma.Web.FedSockets
 
   require Logger
   require Pleroma.Constants
@@ -182,9 +183,47 @@ defmodule Pleroma.Object.Fetcher do
     end
   end
 
-  def fetch_and_contain_remote_object_from_id(id) when is_binary(id) do
+  def fetch_and_contain_remote_object_from_id(prm, opts \\ [])
+
+  def fetch_and_contain_remote_object_from_id(%{"id" => id}, opts),
+    do: fetch_and_contain_remote_object_from_id(id, opts)
+
+  def fetch_and_contain_remote_object_from_id(id, opts) when is_binary(id) do
     Logger.debug("Fetching object #{id} via AP")
 
+    with {:scheme, true} <- {:scheme, String.starts_with?(id, "http")},
+         {:ok, body} <- get_object(id, opts),
+         {:ok, data} <- safe_json_decode(body),
+         :ok <- Containment.contain_origin_from_id(id, data) do
+      {:ok, data}
+    else
+      {:scheme, _} ->
+        {:error, "Unsupported URI scheme"}
+
+      {:error, e} ->
+        {:error, e}
+
+      e ->
+        {:error, e}
+    end
+  end
+
+  def fetch_and_contain_remote_object_from_id(_id, _opts),
+    do: {:error, "id must be a string"}
+
+  defp get_object(id, opts) do
+    with false <- Keyword.get(opts, :force_http, false),
+         {:ok, fedsocket} <- FedSockets.get_or_create_fed_socket(id) do
+      Logger.debug("fetching via fedsocket - #{inspect(id)}")
+      FedSockets.fetch(fedsocket, id)
+    else
+      _other ->
+        Logger.debug("fetching via http - #{inspect(id)}")
+        get_object_http(id)
+    end
+  end
+
+  defp get_object_http(id) do
     date = Pleroma.Signature.signed_date()
 
     headers =
@@ -192,20 +231,13 @@ defmodule Pleroma.Object.Fetcher do
       |> maybe_date_fetch(date)
       |> sign_fetch(id, date)
 
-    Logger.debug("Fetch headers: #{inspect(headers)}")
+    case HTTP.get(id, headers) do
+      {:ok, %{body: body, status: code}} when code in 200..299 ->
+        {:ok, body}
 
-    with {:scheme, true} <- {:scheme, String.starts_with?(id, "http")},
-         {:ok, %{body: body, status: code}} when code in 200..299 <- HTTP.get(id, headers),
-         {:ok, data} <- Jason.decode(body),
-         :ok <- Containment.contain_origin_from_id(id, data) do
-      {:ok, data}
-    else
       {:ok, %{status: code}} when code in [404, 410] ->
         {:error, "Object has been deleted"}
 
-      {:scheme, _} ->
-        {:error, "Unsupported URI scheme"}
-
       {:error, e} ->
         {:error, e}
 
@@ -214,8 +246,6 @@ defmodule Pleroma.Object.Fetcher do
     end
   end
 
-  def fetch_and_contain_remote_object_from_id(%{"id" => id}),
-    do: fetch_and_contain_remote_object_from_id(id)
-
-  def fetch_and_contain_remote_object_from_id(_id), do: {:error, "id must be a string"}
+  defp safe_json_decode(nil), do: {:ok, nil}
+  defp safe_json_decode(json), do: Jason.decode(json)
 end
diff --git a/lib/pleroma/reverse_proxy/reverse_proxy.ex b/lib/pleroma/reverse_proxy/reverse_proxy.ex
index 0de4e2309..8ae1157df 100644
--- a/lib/pleroma/reverse_proxy/reverse_proxy.ex
+++ b/lib/pleroma/reverse_proxy/reverse_proxy.ex
@@ -17,6 +17,9 @@ defmodule Pleroma.ReverseProxy do
   @failed_request_ttl :timer.seconds(60)
   @methods ~w(GET HEAD)
 
+  def max_read_duration_default, do: @max_read_duration
+  def default_cache_control_header, do: @default_cache_control_header
+
   @moduledoc """
   A reverse proxy.
 
@@ -391,6 +394,8 @@ defmodule Pleroma.ReverseProxy do
 
   defp body_size_constraint(_, _), do: :ok
 
+  defp check_read_duration(nil = _duration, max), do: check_read_duration(@max_read_duration, max)
+
   defp check_read_duration(duration, max)
        when is_integer(duration) and is_integer(max) and max > 0 do
     if duration > max do
diff --git a/lib/pleroma/signature.ex b/lib/pleroma/signature.ex
index 3aa6909d2..e388993b7 100644
--- a/lib/pleroma/signature.ex
+++ b/lib/pleroma/signature.ex
@@ -39,7 +39,7 @@ defmodule Pleroma.Signature do
   def fetch_public_key(conn) do
     with %{"keyId" => kid} <- HTTPSignatures.signature_for_conn(conn),
          {:ok, actor_id} <- key_id_to_actor_id(kid),
-         {:ok, public_key} <- User.get_public_key_for_ap_id(actor_id) do
+         {:ok, public_key} <- User.get_public_key_for_ap_id(actor_id, force_http: true) do
       {:ok, public_key}
     else
       e ->
@@ -50,8 +50,8 @@ defmodule Pleroma.Signature do
   def refetch_public_key(conn) do
     with %{"keyId" => kid} <- HTTPSignatures.signature_for_conn(conn),
          {:ok, actor_id} <- key_id_to_actor_id(kid),
-         {:ok, _user} <- ActivityPub.make_user_from_ap_id(actor_id),
-         {:ok, public_key} <- User.get_public_key_for_ap_id(actor_id) do
+         {:ok, _user} <- ActivityPub.make_user_from_ap_id(actor_id, force_http: true),
+         {:ok, public_key} <- User.get_public_key_for_ap_id(actor_id, force_http: true) do
       {:ok, public_key}
     else
       e ->
diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index cf72985fe..410c9cbac 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -1769,12 +1769,12 @@ defmodule Pleroma.User do
 
   def html_filter_policy(_), do: Config.get([:markup, :scrub_policy])
 
-  def fetch_by_ap_id(ap_id), do: ActivityPub.make_user_from_ap_id(ap_id)
+  def fetch_by_ap_id(ap_id, opts \\ []), do: ActivityPub.make_user_from_ap_id(ap_id, opts)
 
-  def get_or_fetch_by_ap_id(ap_id) do
+  def get_or_fetch_by_ap_id(ap_id, opts \\ []) do
     cached_user = get_cached_by_ap_id(ap_id)
 
-    maybe_fetched_user = needs_update?(cached_user) && fetch_by_ap_id(ap_id)
+    maybe_fetched_user = needs_update?(cached_user) && fetch_by_ap_id(ap_id, opts)
 
     case {cached_user, maybe_fetched_user} do
       {_, {:ok, %User{} = user}} ->
@@ -1847,8 +1847,8 @@ defmodule Pleroma.User do
 
   def public_key(_), do: {:error, "key not found"}
 
-  def get_public_key_for_ap_id(ap_id) do
-    with {:ok, %User{} = user} <- get_or_fetch_by_ap_id(ap_id),
+  def get_public_key_for_ap_id(ap_id, opts \\ []) do
+    with {:ok, %User{} = user} <- get_or_fetch_by_ap_id(ap_id, opts),
          {:ok, public_key} <- public_key(user) do
       {:ok, public_key}
     else
diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 92fc1e422..06e8e1a7c 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -1270,10 +1270,12 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
 
   def fetch_follow_information_for_user(user) do
     with {:ok, following_data} <-
-           Fetcher.fetch_and_contain_remote_object_from_id(user.following_address),
+           Fetcher.fetch_and_contain_remote_object_from_id(user.following_address,
+             force_http: true
+           ),
          {:ok, hide_follows} <- collection_private(following_data),
          {:ok, followers_data} <-
-           Fetcher.fetch_and_contain_remote_object_from_id(user.follower_address),
+           Fetcher.fetch_and_contain_remote_object_from_id(user.follower_address, force_http: true),
          {:ok, hide_followers} <- collection_private(followers_data) do
       {:ok,
        %{
@@ -1347,8 +1349,8 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     end
   end
 
-  def fetch_and_prepare_user_from_ap_id(ap_id) do
-    with {:ok, data} <- Fetcher.fetch_and_contain_remote_object_from_id(ap_id),
+  def fetch_and_prepare_user_from_ap_id(ap_id, opts \\ []) do
+    with {:ok, data} <- Fetcher.fetch_and_contain_remote_object_from_id(ap_id, opts),
          {:ok, data} <- user_data_from_user_object(data) do
       {:ok, maybe_update_follow_information(data)}
     else
@@ -1390,13 +1392,13 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     end
   end
 
-  def make_user_from_ap_id(ap_id) do
+  def make_user_from_ap_id(ap_id, opts \\ []) do
     user = User.get_cached_by_ap_id(ap_id)
 
     if user && !User.ap_enabled?(user) do
       Transmogrifier.upgrade_user_from_ap_id(ap_id)
     else
-      with {:ok, data} <- fetch_and_prepare_user_from_ap_id(ap_id) do
+      with {:ok, data} <- fetch_and_prepare_user_from_ap_id(ap_id, opts) do
         if user do
           user
           |> User.remote_user_changeset(data)
diff --git a/lib/pleroma/web/activity_pub/mrf/media_proxy_warming_policy.ex b/lib/pleroma/web/activity_pub/mrf/media_proxy_warming_policy.ex
index 98d595469..0fb05d3c4 100644
--- a/lib/pleroma/web/activity_pub/mrf/media_proxy_warming_policy.ex
+++ b/lib/pleroma/web/activity_pub/mrf/media_proxy_warming_policy.ex
@@ -12,17 +12,21 @@ defmodule Pleroma.Web.ActivityPub.MRF.MediaProxyWarmingPolicy do
 
   require Logger
 
-  @options [
+  @adapter_options [
     pool: :media,
     recv_timeout: 10_000
   ]
 
   def perform(:prefetch, url) do
-    Logger.debug("Prefetching #{inspect(url)}")
+    # Fetching only proxiable resources
+    if MediaProxy.enabled?() and MediaProxy.url_proxiable?(url) do
+      # If preview proxy is enabled, it'll also hit media proxy (so we're caching both requests)
+      prefetch_url = MediaProxy.preview_url(url)
 
-    url
-    |> MediaProxy.url()
-    |> HTTP.get([], @options)
+      Logger.debug("Prefetching #{inspect(url)} as #{inspect(prefetch_url)}")
+
+      HTTP.get(prefetch_url, [], @adapter_options)
+    end
   end
 
   def perform(:preload, %{"object" => %{"attachment" => attachments}} = _message) do
diff --git a/lib/pleroma/web/activity_pub/publisher.ex b/lib/pleroma/web/activity_pub/publisher.ex
index d88f7f3ee..9c3956683 100644
--- a/lib/pleroma/web/activity_pub/publisher.ex
+++ b/lib/pleroma/web/activity_pub/publisher.ex
@@ -13,6 +13,7 @@ defmodule Pleroma.Web.ActivityPub.Publisher do
   alias Pleroma.User
   alias Pleroma.Web.ActivityPub.Relay
   alias Pleroma.Web.ActivityPub.Transmogrifier
+  alias Pleroma.Web.FedSockets
 
   require Pleroma.Constants
 
@@ -50,15 +51,35 @@ defmodule Pleroma.Web.ActivityPub.Publisher do
   def publish_one(%{inbox: inbox, json: json, actor: %User{} = actor, id: id} = params) do
     Logger.debug("Federating #{id} to #{inbox}")
 
-    uri = URI.parse(inbox)
+    case FedSockets.get_or_create_fed_socket(inbox) do
+      {:ok, fedsocket} ->
+        Logger.debug("publishing via fedsockets - #{inspect(inbox)}")
+        FedSockets.publish(fedsocket, json)
 
+      _ ->
+        Logger.debug("publishing via http - #{inspect(inbox)}")
+        http_publish(inbox, actor, json, params)
+    end
+  end
+
+  def publish_one(%{actor_id: actor_id} = params) do
+    actor = User.get_cached_by_id(actor_id)
+
+    params
+    |> Map.delete(:actor_id)
+    |> Map.put(:actor, actor)
+    |> publish_one()
+  end
+
+  defp http_publish(inbox, actor, json, params) do
+    uri = %{path: path} = URI.parse(inbox)
     digest = "SHA-256=" <> (:crypto.hash(:sha256, json) |> Base.encode64())
 
     date = Pleroma.Signature.signed_date()
 
     signature =
       Pleroma.Signature.sign(actor, %{
-        "(request-target)": "post #{uri.path}",
+        "(request-target)": "post #{path}",
         host: signature_host(uri),
         "content-length": byte_size(json),
         digest: digest,
@@ -89,15 +110,6 @@ defmodule Pleroma.Web.ActivityPub.Publisher do
     end
   end
 
-  def publish_one(%{actor_id: actor_id} = params) do
-    actor = User.get_cached_by_id(actor_id)
-
-    params
-    |> Map.delete(:actor_id)
-    |> Map.put(:actor, actor)
-    |> publish_one()
-  end
-
   defp signature_host(%URI{port: port, scheme: scheme, host: host}) do
     if port == URI.default_port(scheme) do
       host
diff --git a/lib/pleroma/web/activity_pub/transmogrifier.ex b/lib/pleroma/web/activity_pub/transmogrifier.ex
index fcca014f0..aa6a69463 100644
--- a/lib/pleroma/web/activity_pub/transmogrifier.ex
+++ b/lib/pleroma/web/activity_pub/transmogrifier.ex
@@ -1000,7 +1000,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
 
   def upgrade_user_from_ap_id(ap_id) do
     with %User{local: false} = user <- User.get_cached_by_ap_id(ap_id),
-         {:ok, data} <- ActivityPub.fetch_and_prepare_user_from_ap_id(ap_id),
+         {:ok, data} <- ActivityPub.fetch_and_prepare_user_from_ap_id(ap_id, force_http: true),
          {:ok, user} <- update_user(user, data) do
       TransmogrifierWorker.enqueue("user_upgrade", %{"user_id" => user.id})
       {:ok, user}
diff --git a/lib/pleroma/web/fed_sockets/fed_registry.ex b/lib/pleroma/web/fed_sockets/fed_registry.ex
new file mode 100644
index 000000000..e00ea69c0
--- /dev/null
+++ b/lib/pleroma/web/fed_sockets/fed_registry.ex
@@ -0,0 +1,185 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.FedSockets.FedRegistry do
+  @moduledoc """
+  The FedRegistry stores the active FedSockets for quick retrieval.
+
+  The storage and retrieval portion of the FedRegistry is done in process through
+  elixir's `Registry` module for speed and its ability to monitor for terminated processes.
+
+  Dropped connections will be caught by `Registry` and deleted. Since the next
+  message will initiate a new connection there is no reason to try and reconnect at that point.
+
+  Normally outside modules should have no need to call or use the FedRegistry themselves.
+  """
+
+  alias Pleroma.Web.FedSockets.FedSocket
+  alias Pleroma.Web.FedSockets.SocketInfo
+
+  require Logger
+
+  @default_rejection_duration 15 * 60 * 1000
+  @rejections :fed_socket_rejections
+
+  @doc """
+  Retrieves a FedSocket from the Registry given it's origin.
+
+  The origin is expected to be a string identifying the endpoint "example.com" or "example2.com:8080"
+
+  Will return:
+    * {:ok, fed_socket} for working FedSockets
+    * {:error, :rejected} for origins that have been tried and refused within the rejection duration interval
+    * {:error, some_reason} usually :missing for unknown origins
+  """
+  def get_fed_socket(origin) do
+    case get_registry_data(origin) do
+      {:error, reason} ->
+        {:error, reason}
+
+      {:ok, %{state: :connected} = socket_info} ->
+        {:ok, socket_info}
+    end
+  end
+
+  @doc """
+  Adds a connected FedSocket to the Registry.
+
+  Always returns {:ok, fed_socket}
+  """
+  def add_fed_socket(origin, pid \\ nil) do
+    origin
+    |> SocketInfo.build(pid)
+    |> SocketInfo.connect()
+    |> add_socket_info
+  end
+
+  defp add_socket_info(%{origin: origin, state: :connected} = socket_info) do
+    case Registry.register(FedSockets.Registry, origin, socket_info) do
+      {:ok, _owner} ->
+        clear_prior_rejection(origin)
+        Logger.debug("fedsocket added: #{inspect(origin)}")
+
+        {:ok, socket_info}
+
+      {:error, {:already_registered, _pid}} ->
+        FedSocket.close(socket_info)
+        existing_socket_info = Registry.lookup(FedSockets.Registry, origin)
+
+        {:ok, existing_socket_info}
+
+      _ ->
+        {:error, :error_adding_socket}
+    end
+  end
+
+  @doc """
+  Mark this origin as having rejected a connection attempt.
+  This will keep it from getting additional connection attempts
+  for a period of time specified in the config.
+
+  Always returns {:ok, new_reg_data}
+  """
+  def set_host_rejected(uri) do
+    new_reg_data =
+      uri
+      |> SocketInfo.origin()
+      |> get_or_create_registry_data()
+      |> set_to_rejected()
+      |> save_registry_data()
+
+    {:ok, new_reg_data}
+  end
+
+  @doc """
+  Retrieves the FedRegistryData from the Registry given it's origin.
+
+  The origin is expected to be a string identifying the endpoint "example.com" or "example2.com:8080"
+
+  Will return:
+    * {:ok, fed_registry_data} for known origins
+    * {:error, :missing} for uniknown origins
+    * {:error, :cache_error} indicating some low level runtime issues
+  """
+  def get_registry_data(origin) do
+    case Registry.lookup(FedSockets.Registry, origin) do
+      [] ->
+        if is_rejected?(origin) do
+          Logger.debug("previously rejected fedsocket requested")
+          {:error, :rejected}
+        else
+          {:error, :missing}
+        end
+
+      [{_pid, %{state: :connected} = socket_info}] ->
+        {:ok, socket_info}
+
+      _ ->
+        {:error, :cache_error}
+    end
+  end
+
+  @doc """
+  Retrieves a map of all sockets from the Registry. The keys are the origins and the values are the corresponding SocketInfo
+  """
+  def list_all do
+    (list_all_connected() ++ list_all_rejected())
+    |> Enum.into(%{})
+  end
+
+  defp list_all_connected do
+    FedSockets.Registry
+    |> Registry.select([{{:"$1", :_, :"$3"}, [], [{{:"$1", :"$3"}}]}])
+  end
+
+  defp list_all_rejected do
+    {:ok, keys} = Cachex.keys(@rejections)
+
+    {:ok, registry_data} =
+      Cachex.execute(@rejections, fn worker ->
+        Enum.map(keys, fn k -> {k, Cachex.get!(worker, k)} end)
+      end)
+
+    registry_data
+  end
+
+  defp clear_prior_rejection(origin),
+    do: Cachex.del(@rejections, origin)
+
+  defp is_rejected?(origin) do
+    case Cachex.get(@rejections, origin) do
+      {:ok, nil} ->
+        false
+
+      {:ok, _} ->
+        true
+    end
+  end
+
+  defp get_or_create_registry_data(origin) do
+    case get_registry_data(origin) do
+      {:error, :missing} ->
+        %SocketInfo{origin: origin}
+
+      {:ok, socket_info} ->
+        socket_info
+    end
+  end
+
+  defp save_registry_data(%SocketInfo{origin: origin, state: :connected} = socket_info) do
+    {:ok, true} = Registry.update_value(FedSockets.Registry, origin, fn _ -> socket_info end)
+    socket_info
+  end
+
+  defp save_registry_data(%SocketInfo{origin: origin, state: :rejected} = socket_info) do
+    rejection_expiration =
+      Pleroma.Config.get([:fed_sockets, :rejection_duration], @default_rejection_duration)
+
+    {:ok, true} = Cachex.put(@rejections, origin, socket_info, ttl: rejection_expiration)
+    socket_info
+  end
+
+  defp set_to_rejected(%SocketInfo{} = socket_info),
+    do: %SocketInfo{socket_info | state: :rejected}
+end
diff --git a/lib/pleroma/web/fed_sockets/fed_socket.ex b/lib/pleroma/web/fed_sockets/fed_socket.ex
new file mode 100644
index 000000000..98d64e65a
--- /dev/null
+++ b/lib/pleroma/web/fed_sockets/fed_socket.ex
@@ -0,0 +1,137 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.FedSockets.FedSocket do
+  @moduledoc """
+  The FedSocket module abstracts the actions to be taken taken on connections regardless of
+  whether the connection started as inbound or outbound.
+
+
+  Normally outside modules will have no need to call the FedSocket module directly.
+  """
+
+  alias Pleroma.Object
+  alias Pleroma.Object.Containment
+  alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.ObjectView
+  alias Pleroma.Web.ActivityPub.UserView
+  alias Pleroma.Web.ActivityPub.Visibility
+  alias Pleroma.Web.FedSockets.FetchRegistry
+  alias Pleroma.Web.FedSockets.IngesterWorker
+  alias Pleroma.Web.FedSockets.OutgoingHandler
+  alias Pleroma.Web.FedSockets.SocketInfo
+
+  require Logger
+
+  @shake "61dd18f7-f1e6-49a4-939a-a749fcdc1103"
+
+  def connect_to_host(uri) do
+    case OutgoingHandler.start_link(uri) do
+      {:ok, pid} ->
+        {:ok, pid}
+
+      error ->
+        {:error, error}
+    end
+  end
+
+  def close(%SocketInfo{pid: socket_pid}),
+    do: Process.send(socket_pid, :close, [])
+
+  def publish(%SocketInfo{pid: socket_pid}, json) do
+    %{action: :publish, data: json}
+    |> Jason.encode!()
+    |> send_packet(socket_pid)
+  end
+
+  def fetch(%SocketInfo{pid: socket_pid}, id) do
+    fetch_uuid = FetchRegistry.register_fetch(id)
+
+    %{action: :fetch, data: id, uuid: fetch_uuid}
+    |> Jason.encode!()
+    |> send_packet(socket_pid)
+
+    wait_for_fetch_to_return(fetch_uuid, 0)
+  end
+
+  def receive_package(%SocketInfo{} = fed_socket, json) do
+    json
+    |> Jason.decode!()
+    |> process_package(fed_socket)
+  end
+
+  defp wait_for_fetch_to_return(uuid, cntr) do
+    case FetchRegistry.check_fetch(uuid) do
+      {:error, :waiting} ->
+        Process.sleep(:math.pow(cntr, 3) |> Kernel.trunc())
+        wait_for_fetch_to_return(uuid, cntr + 1)
+
+      {:error, :missing} ->
+        Logger.error("FedSocket fetch timed out - #{inspect(uuid)}")
+        {:error, :timeout}
+
+      {:ok, _fr} ->
+        FetchRegistry.pop_fetch(uuid)
+    end
+  end
+
+  defp process_package(%{"action" => "publish", "data" => data}, %{origin: origin} = _fed_socket) do
+    if Containment.contain_origin(origin, data) do
+      IngesterWorker.enqueue("ingest", %{"object" => data})
+    end
+
+    {:reply, %{"action" => "publish_reply", "status" => "processed"}}
+  end
+
+  defp process_package(%{"action" => "fetch_reply", "uuid" => uuid, "data" => data}, _fed_socket) do
+    FetchRegistry.register_fetch_received(uuid, data)
+    {:noreply, nil}
+  end
+
+  defp process_package(%{"action" => "fetch", "uuid" => uuid, "data" => ap_id}, _fed_socket) do
+    {:ok, data} = render_fetched_data(ap_id, uuid)
+    {:reply, data}
+  end
+
+  defp process_package(%{"action" => "publish_reply"}, _fed_socket) do
+    {:noreply, nil}
+  end
+
+  defp process_package(other, _fed_socket) do
+    Logger.warn("unknown json packages received #{inspect(other)}")
+    {:noreply, nil}
+  end
+
+  defp render_fetched_data(ap_id, uuid) do
+    {:ok,
+     %{
+       "action" => "fetch_reply",
+       "status" => "processed",
+       "uuid" => uuid,
+       "data" => represent_item(ap_id)
+     }}
+  end
+
+  defp represent_item(ap_id) do
+    case User.get_by_ap_id(ap_id) do
+      nil ->
+        object = Object.get_cached_by_ap_id(ap_id)
+
+        if Visibility.is_public?(object) do
+          Phoenix.View.render_to_string(ObjectView, "object.json", object: object)
+        else
+          nil
+        end
+
+      user ->
+        Phoenix.View.render_to_string(UserView, "user.json", user: user)
+    end
+  end
+
+  defp send_packet(data, socket_pid) do
+    Process.send(socket_pid, {:send, data}, [])
+  end
+
+  def shake, do: @shake
+end
diff --git a/lib/pleroma/web/fed_sockets/fed_sockets.ex b/lib/pleroma/web/fed_sockets/fed_sockets.ex
new file mode 100644
index 000000000..1fd5899c8
--- /dev/null
+++ b/lib/pleroma/web/fed_sockets/fed_sockets.ex
@@ -0,0 +1,185 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.FedSockets do
+  @moduledoc """
+  This documents the FedSockets framework. A framework for federating
+  ActivityPub objects between servers via persistant WebSocket connections.
+
+  FedSockets allow servers to authenticate on first contact and maintain that
+  connection, eliminating the need to authenticate every time data needs to be shared.
+
+  ## Protocol
+  FedSockets currently support 2 types of data transfer:
+    * `publish` method which doesn't require a response
+    * `fetch` method requires a response be sent
+
+    ### Publish
+    The publish operation sends a json encoded map of the shape:
+      %{action: :publish, data: json}
+    and accepts (but does not require) a reply of form:
+      %{"action" => "publish_reply"}
+
+    The outgoing params represent
+      * data: ActivityPub object encoded into json
+
+
+    ### Fetch
+    The fetch operation sends a json encoded map of the shape:
+      %{action: :fetch, data: id, uuid: fetch_uuid}
+    and requires a reply of form:
+      %{"action" => "fetch_reply", "uuid" => uuid, "data" => data}
+
+    The outgoing params represent
+      * id: an ActivityPub object URI
+      * uuid: a unique uuid generated by the sender
+
+    The reply params represent
+      * data: an ActivityPub object encoded into json
+      * uuid: the uuid sent along with the fetch request
+
+  ## Examples
+  Clients of FedSocket transfers shouldn't need to use any of the functions outside of this module.
+
+  A typical publish operation can be performed through the following code, and a fetch operation in a similar manner.
+
+    case FedSockets.get_or_create_fed_socket(inbox) do
+      {:ok, fedsocket} ->
+        FedSockets.publish(fedsocket, json)
+
+      _ ->
+        alternative_publish(inbox, actor, json, params)
+    end
+
+  ## Configuration
+  FedSockets have the following config settings
+
+  config :pleroma, :fed_sockets,
+  enabled: true,
+  ping_interval: :timer.seconds(15),
+  connection_duration: :timer.hours(1),
+  rejection_duration: :timer.hours(1),
+  fed_socket_fetches: [
+    default: 12_000,
+    interval: 3_000,
+    lazy: false
+  ]
+    * enabled - turn FedSockets on or off with this flag. Can be toggled at runtime.
+    * connection_duration - How long a FedSocket can sit idle before it's culled.
+    * rejection_duration - After failing to make a FedSocket connection a host will be excluded
+    from further connections for this amount of time
+    * fed_socket_fetches - Use these parameters to pass options to the Cachex queue backing the FetchRegistry
+    * fed_socket_rejections - Use these parameters to pass options to the Cachex queue backing the FedRegistry
+
+    Cachex options are
+      * default: the minimum amount of time a fetch can wait before it times out.
+      * interval: the interval between checks for timed out entries. This plus the default represent the maximum time allowed
+      * lazy: leave at false for consistant and fast lookups, set to true for stricter timeout enforcement
+
+  """
+  require Logger
+
+  alias Pleroma.Web.FedSockets.FedRegistry
+  alias Pleroma.Web.FedSockets.FedSocket
+  alias Pleroma.Web.FedSockets.SocketInfo
+
+  @doc """
+  returns a FedSocket for the given origin. Will reuse an existing one or create a new one.
+
+  address is expected to be a fully formed URL such as:
+  "http://www.example.com" or "http://www.example.com:8080"
+
+  It can and usually does include additional path parameters,
+  but these are ignored as the FedSockets are organized by host and port info alone.
+  """
+  def get_or_create_fed_socket(address) do
+    with {:cache, {:error, :missing}} <- {:cache, get_fed_socket(address)},
+         {:connect, {:ok, _pid}} <- {:connect, FedSocket.connect_to_host(address)},
+         {:cache, {:ok, fed_socket}} <- {:cache, get_fed_socket(address)} do
+      Logger.debug("fedsocket created for - #{inspect(address)}")
+      {:ok, fed_socket}
+    else
+      {:cache, {:ok, socket}} ->
+        Logger.debug("fedsocket found in cache - #{inspect(address)}")
+        {:ok, socket}
+
+      {:cache, {:error, :rejected} = e} ->
+        e
+
+      {:connect, {:error, _host}} ->
+        Logger.debug("set host rejected for - #{inspect(address)}")
+        FedRegistry.set_host_rejected(address)
+        {:error, :rejected}
+
+      {_, {:error, :disabled}} ->
+        {:error, :disabled}
+
+      {_, {:error, reason}} ->
+        Logger.warn("get_or_create_fed_socket error - #{inspect(reason)}")
+        {:error, reason}
+    end
+  end
+
+  @doc """
+  returns a FedSocket for the given origin. Will not create a new FedSocket if one does not exist.
+
+  address is expected to be a fully formed URL such as:
+    "http://www.example.com" or "http://www.example.com:8080"
+  """
+  def get_fed_socket(address) do
+    origin = SocketInfo.origin(address)
+
+    with {:config, true} <- {:config, Pleroma.Config.get([:fed_sockets, :enabled], false)},
+         {:ok, socket} <- FedRegistry.get_fed_socket(origin) do
+      {:ok, socket}
+    else
+      {:config, _} ->
+        {:error, :disabled}
+
+      {:error, :rejected} ->
+        Logger.debug("FedSocket previously rejected - #{inspect(origin)}")
+        {:error, :rejected}
+
+      {:error, reason} ->
+        {:error, reason}
+    end
+  end
+
+  @doc """
+  Sends the supplied data via the publish protocol.
+  It will not block waiting for a reply.
+  Returns :ok but this is not an indication of a successful transfer.
+
+  the data is expected to be JSON encoded binary data.
+  """
+  def publish(%SocketInfo{} = fed_socket, json) do
+    FedSocket.publish(fed_socket, json)
+  end
+
+  @doc """
+  Sends the supplied data via the fetch protocol.
+  It will block waiting for a reply or timeout.
+
+  Returns {:ok, object} where object is the requested object (or nil)
+          {:error, :timeout} in the event the message was not responded to
+
+  the id is expected to be the URI of an ActivityPub object.
+  """
+  def fetch(%SocketInfo{} = fed_socket, id) do
+    FedSocket.fetch(fed_socket, id)
+  end
+
+  @doc """
+  Disconnect all and restart FedSockets.
+  This is mainly used in development and testing but could be useful in production.
+  """
+  def reset do
+    FedRegistry
+    |> Process.whereis()
+    |> Process.exit(:testing)
+  end
+
+  def uri_for_origin(origin),
+    do: "ws://#{origin}/api/fedsocket/v1"
+end
diff --git a/lib/pleroma/web/fed_sockets/fetch_registry.ex b/lib/pleroma/web/fed_sockets/fetch_registry.ex
new file mode 100644
index 000000000..7897f0fc6
--- /dev/null
+++ b/lib/pleroma/web/fed_sockets/fetch_registry.ex
@@ -0,0 +1,151 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.FedSockets.FetchRegistry do
+  @moduledoc """
+  The FetchRegistry acts as a broker for fetch requests and return values.
+  This allows calling processes to block while waiting for a reply.
+  It doesn't impose it's own process instead using `Cachex` to handle fetches in process, allowing
+  multi threaded processes to avoid bottlenecking.
+
+  Normally outside modules will have no need to call or use the FetchRegistry themselves.
+
+  The `Cachex` parameters can be controlled from the config. Since exact timeout intervals
+  aren't necessary the following settings are used by default:
+
+  config :pleroma, :fed_sockets,
+    fed_socket_fetches: [
+      default: 12_000,
+      interval: 3_000,
+      lazy: false
+    ]
+
+  """
+
+  defmodule FetchRegistryData do
+    defstruct uuid: nil,
+              sent_json: nil,
+              received_json: nil,
+              sent_at: nil,
+              received_at: nil
+  end
+
+  alias Ecto.UUID
+
+  require Logger
+
+  @fetches :fed_socket_fetches
+
+  @doc """
+  Registers a json request wth the FetchRegistry and returns the identifying UUID.
+  """
+  def register_fetch(json) do
+    %FetchRegistryData{uuid: uuid} =
+      json
+      |> new_registry_data
+      |> save_registry_data
+
+    uuid
+  end
+
+  @doc """
+  Reports on the status of a Fetch given the identifying UUID.
+
+  Will return
+    * {:ok, fetched_object} if a fetch has completed
+    * {:error, :waiting} if a fetch is still pending
+    * {:error, other_error} usually :missing to indicate a fetch that has timed out
+  """
+  def check_fetch(uuid) do
+    case get_registry_data(uuid) do
+      {:ok, %FetchRegistryData{received_at: nil}} ->
+        {:error, :waiting}
+
+      {:ok, %FetchRegistryData{} = reg_data} ->
+        {:ok, reg_data}
+
+      e ->
+        e
+    end
+  end
+
+  @doc """
+  Retrieves the response to a fetch given the identifying UUID.
+  The completed fetch will be deleted from the FetchRegistry
+
+  Will return
+    * {:ok, fetched_object} if a fetch has completed
+    * {:error, :waiting} if a fetch is still pending
+    * {:error, other_error} usually :missing to indicate a fetch that has timed out
+  """
+  def pop_fetch(uuid) do
+    case check_fetch(uuid) do
+      {:ok, %FetchRegistryData{received_json: received_json}} ->
+        delete_registry_data(uuid)
+        {:ok, received_json}
+
+      e ->
+        e
+    end
+  end
+
+  @doc """
+  This is called to register a fetch has returned.
+  It expects the result data along with the UUID that was sent in the request
+
+  Will return the fetched object or :error
+  """
+  def register_fetch_received(uuid, data) do
+    case get_registry_data(uuid) do
+      {:ok, %FetchRegistryData{received_at: nil} = reg_data} ->
+        reg_data
+        |> set_fetch_received(data)
+        |> save_registry_data()
+
+      {:ok, %FetchRegistryData{} = reg_data} ->
+        Logger.warn("tried to add fetched data twice - #{uuid}")
+        reg_data
+
+      {:error, _} ->
+        Logger.warn("Error adding fetch to registry - #{uuid}")
+        :error
+    end
+  end
+
+  defp new_registry_data(json) do
+    %FetchRegistryData{
+      uuid: UUID.generate(),
+      sent_json: json,
+      sent_at: :erlang.monotonic_time(:millisecond)
+    }
+  end
+
+  defp get_registry_data(origin) do
+    case Cachex.get(@fetches, origin) do
+      {:ok, nil} ->
+        {:error, :missing}
+
+      {:ok, reg_data} ->
+        {:ok, reg_data}
+
+      _ ->
+        {:error, :cache_error}
+    end
+  end
+
+  defp set_fetch_received(%FetchRegistryData{} = reg_data, data),
+    do: %FetchRegistryData{
+      reg_data
+      | received_at: :erlang.monotonic_time(:millisecond),
+        received_json: data
+    }
+
+  defp save_registry_data(%FetchRegistryData{uuid: uuid} = reg_data) do
+    {:ok, true} = Cachex.put(@fetches, uuid, reg_data)
+    reg_data
+  end
+
+  defp delete_registry_data(origin),
+    do: {:ok, true} = Cachex.del(@fetches, origin)
+end
diff --git a/lib/pleroma/web/fed_sockets/incoming_handler.ex b/lib/pleroma/web/fed_sockets/incoming_handler.ex
new file mode 100644
index 000000000..49d0d9d84
--- /dev/null
+++ b/lib/pleroma/web/fed_sockets/incoming_handler.ex
@@ -0,0 +1,88 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.FedSockets.IncomingHandler do
+  require Logger
+
+  alias Pleroma.Web.FedSockets.FedRegistry
+  alias Pleroma.Web.FedSockets.FedSocket
+  alias Pleroma.Web.FedSockets.SocketInfo
+
+  import HTTPSignatures, only: [validate_conn: 1, split_signature: 1]
+
+  @behaviour :cowboy_websocket
+
+  def init(req, state) do
+    shake = FedSocket.shake()
+
+    with true <- Pleroma.Config.get([:fed_sockets, :enabled]),
+         sec_protocol <- :cowboy_req.header("sec-websocket-protocol", req, nil),
+         headers = %{"(request-target)" => ^shake} <- :cowboy_req.headers(req),
+         true <- validate_conn(%{req_headers: headers}),
+         %{"keyId" => origin} <- split_signature(headers["signature"]) do
+      req =
+        if is_nil(sec_protocol) do
+          req
+        else
+          :cowboy_req.set_resp_header("sec-websocket-protocol", sec_protocol, req)
+        end
+
+      {:cowboy_websocket, req, %{origin: origin}, %{}}
+    else
+      _ ->
+        {:ok, req, state}
+    end
+  end
+
+  def websocket_init(%{origin: origin}) do
+    case FedRegistry.add_fed_socket(origin) do
+      {:ok, socket_info} ->
+        {:ok, socket_info}
+
+      e ->
+        Logger.error("FedSocket websocket_init failed - #{inspect(e)}")
+        {:error, inspect(e)}
+    end
+  end
+
+  # Use the ping to  check if the connection should be expired
+  def websocket_handle(:ping, socket_info) do
+    if SocketInfo.expired?(socket_info) do
+      {:stop, socket_info}
+    else
+      {:ok, socket_info, :hibernate}
+    end
+  end
+
+  def websocket_handle({:text, data}, socket_info) do
+    socket_info = SocketInfo.touch(socket_info)
+
+    case FedSocket.receive_package(socket_info, data) do
+      {:noreply, _} ->
+        {:ok, socket_info}
+
+      {:reply, reply} ->
+        {:reply, {:text, Jason.encode!(reply)}, socket_info}
+
+      {:error, reason} ->
+        Logger.error("incoming error - receive_package: #{inspect(reason)}")
+        {:ok, socket_info}
+    end
+  end
+
+  def websocket_info({:send, message}, socket_info) do
+    socket_info = SocketInfo.touch(socket_info)
+
+    {:reply, {:text, message}, socket_info}
+  end
+
+  def websocket_info(:close, state) do
+    {:stop, state}
+  end
+
+  def websocket_info(message, state) do
+    Logger.debug("#{__MODULE__} unknown message #{inspect(message)}")
+    {:ok, state}
+  end
+end
diff --git a/lib/pleroma/web/fed_sockets/ingester_worker.ex b/lib/pleroma/web/fed_sockets/ingester_worker.ex
new file mode 100644
index 000000000..325f2a4ab
--- /dev/null
+++ b/lib/pleroma/web/fed_sockets/ingester_worker.ex
@@ -0,0 +1,33 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.FedSockets.IngesterWorker do
+  use Pleroma.Workers.WorkerHelper, queue: "ingestion_queue"
+  require Logger
+
+  alias Pleroma.Web.Federator
+
+  @impl Oban.Worker
+  def perform(%Job{args: %{"op" => "ingest", "object" => ingestee}}) do
+    try do
+      ingestee
+      |> Jason.decode!()
+      |> do_ingestion()
+    rescue
+      e ->
+        Logger.error("IngesterWorker error - #{inspect(e)}")
+        e
+    end
+  end
+
+  defp do_ingestion(params) do
+    case Federator.incoming_ap_doc(params) do
+      {:error, reason} ->
+        {:error, reason}
+
+      {:ok, object} ->
+        {:ok, object}
+    end
+  end
+end
diff --git a/lib/pleroma/web/fed_sockets/outgoing_handler.ex b/lib/pleroma/web/fed_sockets/outgoing_handler.ex
new file mode 100644
index 000000000..6ddef17fe
--- /dev/null
+++ b/lib/pleroma/web/fed_sockets/outgoing_handler.ex
@@ -0,0 +1,146 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.FedSockets.OutgoingHandler do
+  use GenServer
+
+  require Logger
+
+  alias Pleroma.Web.ActivityPub.InternalFetchActor
+  alias Pleroma.Web.FedSockets
+  alias Pleroma.Web.FedSockets.FedRegistry
+  alias Pleroma.Web.FedSockets.FedSocket
+  alias Pleroma.Web.FedSockets.SocketInfo
+
+  def start_link(uri) do
+    GenServer.start_link(__MODULE__, %{uri: uri})
+  end
+
+  def init(%{uri: uri}) do
+    case initiate_connection(uri) do
+      {:ok, ws_origin, conn_pid} ->
+        FedRegistry.add_fed_socket(ws_origin, conn_pid)
+
+      {:error, reason} ->
+        Logger.debug("Outgoing connection failed - #{inspect(reason)}")
+        :ignore
+    end
+  end
+
+  def handle_info({:gun_ws, conn_pid, _ref, {:text, data}}, socket_info) do
+    socket_info = SocketInfo.touch(socket_info)
+
+    case FedSocket.receive_package(socket_info, data) do
+      {:noreply, _} ->
+        {:noreply, socket_info}
+
+      {:reply, reply} ->
+        :gun.ws_send(conn_pid, {:text, Jason.encode!(reply)})
+        {:noreply, socket_info}
+
+      {:error, reason} ->
+        Logger.error("incoming error - receive_package: #{inspect(reason)}")
+        {:noreply, socket_info}
+    end
+  end
+
+  def handle_info(:close, state) do
+    Logger.debug("Sending close frame !!!!!!!")
+    {:close, state}
+  end
+
+  def handle_info({:gun_down, _pid, _prot, :closed, _}, state) do
+    {:stop, :normal, state}
+  end
+
+  def handle_info({:send, data}, %{conn_pid: conn_pid} = socket_info) do
+    socket_info = SocketInfo.touch(socket_info)
+    :gun.ws_send(conn_pid, {:text, data})
+    {:noreply, socket_info}
+  end
+
+  def handle_info({:gun_ws, _, _, :pong}, state) do
+    {:noreply, state, :hibernate}
+  end
+
+  def handle_info(msg, state) do
+    Logger.debug("#{__MODULE__} unhandled event #{inspect(msg)}")
+    {:noreply, state}
+  end
+
+  def terminate(reason, state) do
+    Logger.debug(
+      "#{__MODULE__} terminating outgoing connection for #{inspect(state)} for #{inspect(reason)}"
+    )
+
+    {:ok, state}
+  end
+
+  def initiate_connection(uri) do
+    ws_uri =
+      uri
+      |> SocketInfo.origin()
+      |> FedSockets.uri_for_origin()
+
+    %{host: host, port: port, path: path} = URI.parse(ws_uri)
+
+    with {:ok, conn_pid} <- :gun.open(to_charlist(host), port),
+         {:ok, _} <- :gun.await_up(conn_pid),
+         reference <- :gun.get(conn_pid, to_charlist(path)),
+         {:response, :fin, 204, _} <- :gun.await(conn_pid, reference),
+         headers <- build_headers(uri),
+         ref <- :gun.ws_upgrade(conn_pid, to_charlist(path), headers, %{silence_pings: false}) do
+      receive do
+        {:gun_upgrade, ^conn_pid, ^ref, [<<"websocket">>], _} ->
+          {:ok, ws_uri, conn_pid}
+      after
+        15_000 ->
+          Logger.debug("Fedsocket timeout connecting to #{inspect(uri)}")
+          {:error, :timeout}
+      end
+    else
+      {:response, :nofin, 404, _} ->
+        {:error, :fedsockets_not_supported}
+
+      e ->
+        Logger.debug("Fedsocket error connecting to #{inspect(uri)}")
+        {:error, e}
+    end
+  end
+
+  defp build_headers(uri) do
+    host_for_sig = uri |> URI.parse() |> host_signature()
+
+    shake = FedSocket.shake()
+    digest = "SHA-256=" <> (:crypto.hash(:sha256, shake) |> Base.encode64())
+    date = Pleroma.Signature.signed_date()
+    shake_size = byte_size(shake)
+
+    signature_opts = %{
+      "(request-target)": shake,
+      "content-length": to_charlist("#{shake_size}"),
+      date: date,
+      digest: digest,
+      host: host_for_sig
+    }
+
+    signature = Pleroma.Signature.sign(InternalFetchActor.get_actor(), signature_opts)
+
+    [
+      {'signature', to_charlist(signature)},
+      {'date', date},
+      {'digest', to_charlist(digest)},
+      {'content-length', to_charlist("#{shake_size}")},
+      {to_charlist("(request-target)"), to_charlist(shake)}
+    ]
+  end
+
+  defp host_signature(%{host: host, scheme: scheme, port: port}) do
+    if port == URI.default_port(scheme) do
+      host
+    else
+      "#{host}:#{port}"
+    end
+  end
+end
diff --git a/lib/pleroma/web/fed_sockets/socket_info.ex b/lib/pleroma/web/fed_sockets/socket_info.ex
new file mode 100644
index 000000000..d6fdffe1a
--- /dev/null
+++ b/lib/pleroma/web/fed_sockets/socket_info.ex
@@ -0,0 +1,52 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.FedSockets.SocketInfo do
+  defstruct origin: nil,
+            pid: nil,
+            conn_pid: nil,
+            state: :default,
+            connected_until: nil
+
+  alias Pleroma.Web.FedSockets.SocketInfo
+  @default_connection_duration 15 * 60 * 1000
+
+  def build(uri, conn_pid \\ nil) do
+    uri
+    |> build_origin()
+    |> build_pids(conn_pid)
+    |> touch()
+  end
+
+  def touch(%SocketInfo{} = socket_info),
+    do: %{socket_info | connected_until: new_ttl()}
+
+  def connect(%SocketInfo{} = socket_info),
+    do: %{socket_info | state: :connected}
+
+  def expired?(%{connected_until: connected_until}),
+    do: connected_until < :erlang.monotonic_time(:millisecond)
+
+  def origin(uri),
+    do: build_origin(uri).origin
+
+  defp build_pids(socket_info, conn_pid),
+    do: struct(socket_info, pid: self(), conn_pid: conn_pid)
+
+  defp build_origin(uri) when is_binary(uri),
+    do: uri |> URI.parse() |> build_origin
+
+  defp build_origin(%{host: host, port: nil, scheme: scheme}),
+    do: build_origin(%{host: host, port: URI.default_port(scheme)})
+
+  defp build_origin(%{host: host, port: port}),
+    do: %SocketInfo{origin: "#{host}:#{port}"}
+
+  defp new_ttl do
+    connection_duration =
+      Pleroma.Config.get([:fed_sockets, :connection_duration], @default_connection_duration)
+
+    :erlang.monotonic_time(:millisecond) + connection_duration
+  end
+end
diff --git a/lib/pleroma/web/fed_sockets/supervisor.ex b/lib/pleroma/web/fed_sockets/supervisor.ex
new file mode 100644
index 000000000..a5f4bebfb
--- /dev/null
+++ b/lib/pleroma/web/fed_sockets/supervisor.ex
@@ -0,0 +1,59 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.FedSockets.Supervisor do
+  use Supervisor
+  import Cachex.Spec
+
+  def start_link(opts) do
+    Supervisor.start_link(__MODULE__, opts, name: __MODULE__)
+  end
+
+  def init(args) do
+    children = [
+      build_cache(:fed_socket_fetches, args),
+      build_cache(:fed_socket_rejections, args),
+      {Registry, keys: :unique, name: FedSockets.Registry, meta: [rejected: %{}]}
+    ]
+
+    opts = [strategy: :one_for_all, name: Pleroma.Web.Streamer.Supervisor]
+    Supervisor.init(children, opts)
+  end
+
+  defp build_cache(name, args) do
+    opts = get_opts(name, args)
+
+    %{
+      id: String.to_atom("#{name}_cache"),
+      start: {Cachex, :start_link, [name, opts]},
+      type: :worker
+    }
+  end
+
+  defp get_opts(cache_name, args)
+       when cache_name in [:fed_socket_fetches, :fed_socket_rejections] do
+    default = get_opts_or_config(args, cache_name, :default, 15_000)
+    interval = get_opts_or_config(args, cache_name, :interval, 3_000)
+    lazy = get_opts_or_config(args, cache_name, :lazy, false)
+
+    [expiration: expiration(default: default, interval: interval, lazy: lazy)]
+  end
+
+  defp get_opts(name, args) do
+    Keyword.get(args, name, [])
+  end
+
+  defp get_opts_or_config(args, name, key, default) do
+    args
+    |> Keyword.get(name, [])
+    |> Keyword.get(key)
+    |> case do
+      nil ->
+        Pleroma.Config.get([:fed_sockets, name, key], default)
+
+      value ->
+        value
+    end
+  end
+end
diff --git a/lib/pleroma/web/mastodon_api/views/account_view.ex b/lib/pleroma/web/mastodon_api/views/account_view.ex
index d2a30a548..121ba1693 100644
--- a/lib/pleroma/web/mastodon_api/views/account_view.ex
+++ b/lib/pleroma/web/mastodon_api/views/account_view.ex
@@ -181,8 +181,10 @@ defmodule Pleroma.Web.MastodonAPI.AccountView do
     user = User.sanitize_html(user, User.html_filter_policy(opts[:for]))
     display_name = user.name || user.nickname
 
-    image = User.avatar_url(user) |> MediaProxy.url()
+    avatar = User.avatar_url(user) |> MediaProxy.url()
+    avatar_static = User.avatar_url(user) |> MediaProxy.preview_url(static: true)
     header = User.banner_url(user) |> MediaProxy.url()
+    header_static = User.banner_url(user) |> MediaProxy.preview_url(static: true)
 
     following_count =
       if !user.hide_follows_count or !user.hide_follows or opts[:for] == user do
@@ -247,10 +249,10 @@ defmodule Pleroma.Web.MastodonAPI.AccountView do
       statuses_count: user.note_count,
       note: user.bio,
       url: user.uri || user.ap_id,
-      avatar: image,
-      avatar_static: image,
+      avatar: avatar,
+      avatar_static: avatar_static,
       header: header,
-      header_static: header,
+      header_static: header_static,
       emojis: emojis,
       fields: user.fields,
       bot: bot,
diff --git a/lib/pleroma/web/mastodon_api/views/status_view.ex b/lib/pleroma/web/mastodon_api/views/status_view.ex
index 94b8dc8c6..435bcde15 100644
--- a/lib/pleroma/web/mastodon_api/views/status_view.ex
+++ b/lib/pleroma/web/mastodon_api/views/status_view.ex
@@ -415,6 +415,7 @@ defmodule Pleroma.Web.MastodonAPI.StatusView do
     [attachment_url | _] = attachment["url"]
     media_type = attachment_url["mediaType"] || attachment_url["mimeType"] || "image"
     href = attachment_url["href"] |> MediaProxy.url()
+    href_preview = attachment_url["href"] |> MediaProxy.preview_url()
 
     type =
       cond do
@@ -430,7 +431,7 @@ defmodule Pleroma.Web.MastodonAPI.StatusView do
       id: to_string(attachment["id"] || hash_id),
       url: href,
       remote_url: href,
-      preview_url: href,
+      preview_url: href_preview,
       text_url: href,
       type: type,
       description: attachment["name"],
diff --git a/lib/pleroma/web/media_proxy/invalidation.ex b/lib/pleroma/web/media_proxy/invalidation.ex
index 5808861e6..4f4340478 100644
--- a/lib/pleroma/web/media_proxy/invalidation.ex
+++ b/lib/pleroma/web/media_proxy/invalidation.ex
@@ -33,6 +33,8 @@ defmodule Pleroma.Web.MediaProxy.Invalidation do
   def prepare_urls(urls) do
     urls
     |> List.wrap()
-    |> Enum.map(&MediaProxy.url/1)
+    |> Enum.map(fn url -> [MediaProxy.url(url), MediaProxy.preview_url(url)] end)
+    |> List.flatten()
+    |> Enum.uniq()
   end
 end
diff --git a/lib/pleroma/web/media_proxy/media_proxy.ex b/lib/pleroma/web/media_proxy/media_proxy.ex
index e18dd8224..8656b8cad 100644
--- a/lib/pleroma/web/media_proxy/media_proxy.ex
+++ b/lib/pleroma/web/media_proxy/media_proxy.ex
@@ -4,6 +4,7 @@
 
 defmodule Pleroma.Web.MediaProxy do
   alias Pleroma.Config
+  alias Pleroma.Helpers.UriHelper
   alias Pleroma.Upload
   alias Pleroma.Web
   alias Pleroma.Web.MediaProxy.Invalidation
@@ -40,27 +41,35 @@ defmodule Pleroma.Web.MediaProxy do
   def url("/" <> _ = url), do: url
 
   def url(url) do
-    if disabled?() or not url_proxiable?(url) do
-      url
-    else
+    if enabled?() and url_proxiable?(url) do
       encode_url(url)
+    else
+      url
     end
   end
 
   @spec url_proxiable?(String.t()) :: boolean()
   def url_proxiable?(url) do
-    if local?(url) or whitelisted?(url) do
-      false
+    not local?(url) and not whitelisted?(url)
+  end
+
+  def preview_url(url, preview_params \\ []) do
+    if preview_enabled?() do
+      encode_preview_url(url, preview_params)
     else
-      true
+      url(url)
     end
   end
 
-  defp disabled?, do: !Config.get([:media_proxy, :enabled], false)
+  def enabled?, do: Config.get([:media_proxy, :enabled], false)
+
+  # Note: media proxy must be enabled for media preview proxy in order to load all
+  #   non-local non-whitelisted URLs through it and be sure that body size constraint is preserved.
+  def preview_enabled?, do: enabled?() and !!Config.get([:media_preview_proxy, :enabled])
 
-  defp local?(url), do: String.starts_with?(url, Pleroma.Web.base_url())
+  def local?(url), do: String.starts_with?(url, Pleroma.Web.base_url())
 
-  defp whitelisted?(url) do
+  def whitelisted?(url) do
     %{host: domain} = URI.parse(url)
 
     mediaproxy_whitelist_domains =
@@ -85,17 +94,29 @@ defmodule Pleroma.Web.MediaProxy do
 
   defp maybe_get_domain_from_url(domain), do: domain
 
-  def encode_url(url) do
+  defp base64_sig64(url) do
     base64 = Base.url_encode64(url, @base64_opts)
 
     sig64 =
       base64
-      |> signed_url
+      |> signed_url()
       |> Base.url_encode64(@base64_opts)
 
+    {base64, sig64}
+  end
+
+  def encode_url(url) do
+    {base64, sig64} = base64_sig64(url)
+
     build_url(sig64, base64, filename(url))
   end
 
+  def encode_preview_url(url, preview_params \\ []) do
+    {base64, sig64} = base64_sig64(url)
+
+    build_preview_url(sig64, base64, filename(url), preview_params)
+  end
+
   def decode_url(sig, url) do
     with {:ok, sig} <- Base.url_decode64(sig, @base64_opts),
          signature when signature == sig <- signed_url(url) do
@@ -113,10 +134,14 @@ defmodule Pleroma.Web.MediaProxy do
     if path = URI.parse(url_or_path).path, do: Path.basename(path)
   end
 
-  def build_url(sig_base64, url_base64, filename \\ nil) do
+  def base_url do
+    Config.get([:media_proxy, :base_url], Web.base_url())
+  end
+
+  defp proxy_url(path, sig_base64, url_base64, filename) do
     [
-      Config.get([:media_proxy, :base_url], Web.base_url()),
-      "proxy",
+      base_url(),
+      path,
       sig_base64,
       url_base64,
       filename
@@ -124,4 +149,38 @@ defmodule Pleroma.Web.MediaProxy do
     |> Enum.filter(& &1)
     |> Path.join()
   end
+
+  def build_url(sig_base64, url_base64, filename \\ nil) do
+    proxy_url("proxy", sig_base64, url_base64, filename)
+  end
+
+  def build_preview_url(sig_base64, url_base64, filename \\ nil, preview_params \\ []) do
+    uri = proxy_url("proxy/preview", sig_base64, url_base64, filename)
+
+    UriHelper.modify_uri_params(uri, preview_params)
+  end
+
+  def verify_request_path_and_url(
+        %Plug.Conn{params: %{"filename" => _}, request_path: request_path},
+        url
+      ) do
+    verify_request_path_and_url(request_path, url)
+  end
+
+  def verify_request_path_and_url(request_path, url) when is_binary(request_path) do
+    filename = filename(url)
+
+    if filename && not basename_matches?(request_path, filename) do
+      {:wrong_filename, filename}
+    else
+      :ok
+    end
+  end
+
+  def verify_request_path_and_url(_, _), do: :ok
+
+  defp basename_matches?(path, filename) do
+    basename = Path.basename(path)
+    basename == filename or URI.decode(basename) == filename or URI.encode(basename) == filename
+  end
 end
diff --git a/lib/pleroma/web/media_proxy/media_proxy_controller.ex b/lib/pleroma/web/media_proxy/media_proxy_controller.ex
index 9a64b0ef3..90651ed9b 100644
--- a/lib/pleroma/web/media_proxy/media_proxy_controller.ex
+++ b/lib/pleroma/web/media_proxy/media_proxy_controller.ex
@@ -5,44 +5,201 @@
 defmodule Pleroma.Web.MediaProxy.MediaProxyController do
   use Pleroma.Web, :controller
 
+  alias Pleroma.Config
+  alias Pleroma.Helpers.MediaHelper
+  alias Pleroma.Helpers.UriHelper
   alias Pleroma.ReverseProxy
   alias Pleroma.Web.MediaProxy
+  alias Plug.Conn
 
-  @default_proxy_opts [max_body_length: 25 * 1_048_576, http: [follow_redirect: true]]
-
-  def remote(conn, %{"sig" => sig64, "url" => url64} = params) do
-    with config <- Pleroma.Config.get([:media_proxy], []),
-         true <- Keyword.get(config, :enabled, false),
+  def remote(conn, %{"sig" => sig64, "url" => url64}) do
+    with {_, true} <- {:enabled, MediaProxy.enabled?()},
          {:ok, url} <- MediaProxy.decode_url(sig64, url64),
          {_, false} <- {:in_banned_urls, MediaProxy.in_banned_urls(url)},
-         :ok <- filename_matches(params, conn.request_path, url) do
-      ReverseProxy.call(conn, url, Keyword.get(config, :proxy_opts, @default_proxy_opts))
+         :ok <- MediaProxy.verify_request_path_and_url(conn, url) do
+      ReverseProxy.call(conn, url, media_proxy_opts())
     else
-      error when error in [false, {:in_banned_urls, true}] ->
-        send_resp(conn, 404, Plug.Conn.Status.reason_phrase(404))
+      {:enabled, false} ->
+        send_resp(conn, 404, Conn.Status.reason_phrase(404))
+
+      {:in_banned_urls, true} ->
+        send_resp(conn, 404, Conn.Status.reason_phrase(404))
 
       {:error, :invalid_signature} ->
-        send_resp(conn, 403, Plug.Conn.Status.reason_phrase(403))
+        send_resp(conn, 403, Conn.Status.reason_phrase(403))
 
       {:wrong_filename, filename} ->
         redirect(conn, external: MediaProxy.build_url(sig64, url64, filename))
     end
   end
 
-  def filename_matches(%{"filename" => _} = _, path, url) do
-    filename = MediaProxy.filename(url)
+  def preview(%Conn{} = conn, %{"sig" => sig64, "url" => url64}) do
+    with {_, true} <- {:enabled, MediaProxy.preview_enabled?()},
+         {:ok, url} <- MediaProxy.decode_url(sig64, url64),
+         :ok <- MediaProxy.verify_request_path_and_url(conn, url) do
+      handle_preview(conn, url)
+    else
+      {:enabled, false} ->
+        send_resp(conn, 404, Conn.Status.reason_phrase(404))
+
+      {:error, :invalid_signature} ->
+        send_resp(conn, 403, Conn.Status.reason_phrase(403))
+
+      {:wrong_filename, filename} ->
+        redirect(conn, external: MediaProxy.build_preview_url(sig64, url64, filename))
+    end
+  end
+
+  defp handle_preview(conn, url) do
+    media_proxy_url = MediaProxy.url(url)
+
+    with {:ok, %{status: status} = head_response} when status in 200..299 <-
+           Pleroma.HTTP.request("head", media_proxy_url, [], [], pool: :media) do
+      content_type = Tesla.get_header(head_response, "content-type")
+      content_length = Tesla.get_header(head_response, "content-length")
+      content_length = content_length && String.to_integer(content_length)
+      static = conn.params["static"] in ["true", true]
+
+      cond do
+        static and content_type == "image/gif" ->
+          handle_jpeg_preview(conn, media_proxy_url)
+
+        static ->
+          drop_static_param_and_redirect(conn)
+
+        content_type == "image/gif" ->
+          redirect(conn, external: media_proxy_url)
+
+        min_content_length_for_preview() > 0 and content_length > 0 and
+            content_length < min_content_length_for_preview() ->
+          redirect(conn, external: media_proxy_url)
+
+        true ->
+          handle_preview(content_type, conn, media_proxy_url)
+      end
+    else
+      # If HEAD failed, redirecting to media proxy URI doesn't make much sense; returning an error
+      {_, %{status: status}} ->
+        send_resp(conn, :failed_dependency, "Can't fetch HTTP headers (HTTP #{status}).")
+
+      {:error, :recv_response_timeout} ->
+        send_resp(conn, :failed_dependency, "HEAD request timeout.")
+
+      _ ->
+        send_resp(conn, :failed_dependency, "Can't fetch HTTP headers.")
+    end
+  end
+
+  defp handle_preview("image/png" <> _ = _content_type, conn, media_proxy_url) do
+    handle_png_preview(conn, media_proxy_url)
+  end
+
+  defp handle_preview("image/" <> _ = _content_type, conn, media_proxy_url) do
+    handle_jpeg_preview(conn, media_proxy_url)
+  end
+
+  defp handle_preview("video/" <> _ = _content_type, conn, media_proxy_url) do
+    handle_video_preview(conn, media_proxy_url)
+  end
+
+  defp handle_preview(_unsupported_content_type, conn, media_proxy_url) do
+    fallback_on_preview_error(conn, media_proxy_url)
+  end
+
+  defp handle_png_preview(conn, media_proxy_url) do
+    quality = Config.get!([:media_preview_proxy, :image_quality])
+    {thumbnail_max_width, thumbnail_max_height} = thumbnail_max_dimensions()
+
+    with {:ok, thumbnail_binary} <-
+           MediaHelper.image_resize(
+             media_proxy_url,
+             %{
+               max_width: thumbnail_max_width,
+               max_height: thumbnail_max_height,
+               quality: quality,
+               format: "png"
+             }
+           ) do
+      conn
+      |> put_preview_response_headers(["image/png", "preview.png"])
+      |> send_resp(200, thumbnail_binary)
+    else
+      _ ->
+        fallback_on_preview_error(conn, media_proxy_url)
+    end
+  end
+
+  defp handle_jpeg_preview(conn, media_proxy_url) do
+    quality = Config.get!([:media_preview_proxy, :image_quality])
+    {thumbnail_max_width, thumbnail_max_height} = thumbnail_max_dimensions()
 
-    if filename && does_not_match(path, filename) do
-      {:wrong_filename, filename}
+    with {:ok, thumbnail_binary} <-
+           MediaHelper.image_resize(
+             media_proxy_url,
+             %{max_width: thumbnail_max_width, max_height: thumbnail_max_height, quality: quality}
+           ) do
+      conn
+      |> put_preview_response_headers()
+      |> send_resp(200, thumbnail_binary)
     else
-      :ok
+      _ ->
+        fallback_on_preview_error(conn, media_proxy_url)
     end
   end
 
-  def filename_matches(_, _, _), do: :ok
+  defp handle_video_preview(conn, media_proxy_url) do
+    with {:ok, thumbnail_binary} <-
+           MediaHelper.video_framegrab(media_proxy_url) do
+      conn
+      |> put_preview_response_headers()
+      |> send_resp(200, thumbnail_binary)
+    else
+      _ ->
+        fallback_on_preview_error(conn, media_proxy_url)
+    end
+  end
+
+  defp drop_static_param_and_redirect(conn) do
+    uri_without_static_param =
+      conn
+      |> current_url()
+      |> UriHelper.modify_uri_params(%{}, ["static"])
+
+    redirect(conn, external: uri_without_static_param)
+  end
+
+  defp fallback_on_preview_error(conn, media_proxy_url) do
+    redirect(conn, external: media_proxy_url)
+  end
+
+  defp put_preview_response_headers(
+         conn,
+         [content_type, filename] = _content_info \\ ["image/jpeg", "preview.jpg"]
+       ) do
+    conn
+    |> put_resp_header("content-type", content_type)
+    |> put_resp_header("content-disposition", "inline; filename=\"#{filename}\"")
+    |> put_resp_header("cache-control", ReverseProxy.default_cache_control_header())
+  end
+
+  defp thumbnail_max_dimensions do
+    config = media_preview_proxy_config()
+
+    thumbnail_max_width = Keyword.fetch!(config, :thumbnail_max_width)
+    thumbnail_max_height = Keyword.fetch!(config, :thumbnail_max_height)
+
+    {thumbnail_max_width, thumbnail_max_height}
+  end
+
+  defp min_content_length_for_preview do
+    Keyword.get(media_preview_proxy_config(), :min_content_length, 0)
+  end
+
+  defp media_preview_proxy_config do
+    Config.get!([:media_preview_proxy])
+  end
 
-  defp does_not_match(path, filename) do
-    basename = Path.basename(path)
-    basename != filename and URI.decode(basename) != filename and URI.encode(basename) != filename
+  defp media_proxy_opts do
+    Config.get([:media_proxy, :proxy_opts], [])
   end
 end
diff --git a/lib/pleroma/web/metadata/utils.ex b/lib/pleroma/web/metadata/utils.ex
index 2f0dfb474..8a206e019 100644
--- a/lib/pleroma/web/metadata/utils.ex
+++ b/lib/pleroma/web/metadata/utils.ex
@@ -38,7 +38,7 @@ defmodule Pleroma.Web.Metadata.Utils do
   def scrub_html(content), do: content
 
   def attachment_url(url) do
-    MediaProxy.url(url)
+    MediaProxy.preview_url(url)
   end
 
   def user_name_string(user) do
diff --git a/lib/pleroma/web/oauth/oauth_controller.ex b/lib/pleroma/web/oauth/oauth_controller.ex
index 26e68be42..a4152e840 100644
--- a/lib/pleroma/web/oauth/oauth_controller.ex
+++ b/lib/pleroma/web/oauth/oauth_controller.ex
@@ -119,7 +119,7 @@ defmodule Pleroma.Web.OAuth.OAuthController do
       redirect_uri = redirect_uri(conn, redirect_uri)
       url_params = %{access_token: token.token}
       url_params = Maps.put_if_present(url_params, :state, params["state"])
-      url = UriHelper.append_uri_params(redirect_uri, url_params)
+      url = UriHelper.modify_uri_params(redirect_uri, url_params)
       redirect(conn, external: url)
     else
       conn
@@ -161,7 +161,7 @@ defmodule Pleroma.Web.OAuth.OAuthController do
       redirect_uri = redirect_uri(conn, redirect_uri)
       url_params = %{code: auth.token}
       url_params = Maps.put_if_present(url_params, :state, auth_attrs["state"])
-      url = UriHelper.append_uri_params(redirect_uri, url_params)
+      url = UriHelper.modify_uri_params(redirect_uri, url_params)
       redirect(conn, external: url)
     else
       conn
diff --git a/lib/pleroma/web/router.ex b/lib/pleroma/web/router.ex
index cd336b932..f924e1e91 100644
--- a/lib/pleroma/web/router.ex
+++ b/lib/pleroma/web/router.ex
@@ -680,6 +680,8 @@ defmodule Pleroma.Web.Router do
   end
 
   scope "/proxy/", Pleroma.Web.MediaProxy do
+    get("/preview/:sig/:url", MediaProxyController, :preview)
+    get("/preview/:sig/:url/:filename", MediaProxyController, :preview)
     get("/:sig/:url", MediaProxyController, :remote)
     get("/:sig/:url/:filename", MediaProxyController, :remote)
   end
diff --git a/mix.lock b/mix.lock
index a28c47017..adb3f024a 100644
--- a/mix.lock
+++ b/mix.lock
@@ -31,6 +31,7 @@
   "ecto": {:hex, :ecto, "3.4.5", "2bcd262f57b2c888b0bd7f7a28c8a48aa11dc1a2c6a858e45dd8f8426d504265", [:mix], [{:decimal, "~> 1.6 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "8c6d1d4d524559e9b7a062f0498e2c206122552d63eacff0a6567ffe7a8e8691"},
   "ecto_enum": {:hex, :ecto_enum, "1.4.0", "d14b00e04b974afc69c251632d1e49594d899067ee2b376277efd8233027aec8", [:mix], [{:ecto, ">= 3.0.0", [hex: :ecto, repo: "hexpm", optional: false]}, {:ecto_sql, "> 3.0.0", [hex: :ecto_sql, repo: "hexpm", optional: false]}, {:mariaex, ">= 0.0.0", [hex: :mariaex, repo: "hexpm", optional: true]}, {:postgrex, ">= 0.0.0", [hex: :postgrex, repo: "hexpm", optional: true]}], "hexpm", "8fb55c087181c2b15eee406519dc22578fa60dd82c088be376d0010172764ee4"},
   "ecto_sql": {:hex, :ecto_sql, "3.4.5", "30161f81b167d561a9a2df4329c10ae05ff36eca7ccc84628f2c8b9fa1e43323", [:mix], [{:db_connection, "~> 2.2", [hex: :db_connection, repo: "hexpm", optional: false]}, {:ecto, "~> 3.4.3", [hex: :ecto, repo: "hexpm", optional: false]}, {:myxql, "~> 0.3.0 or ~> 0.4.0", [hex: :myxql, repo: "hexpm", optional: true]}, {:postgrex, "~> 0.15.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:tds, "~> 2.1.0", [hex: :tds, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "31990c6a3579b36a3c0841d34a94c275e727de8b84f58509da5f1b2032c98ac2"},
+  "eimp": {:hex, :eimp, "1.0.14", "fc297f0c7e2700457a95a60c7010a5f1dcb768a083b6d53f49cd94ab95a28f22", [:rebar3], [{:p1_utils, "1.0.18", [hex: :p1_utils, repo: "hexpm", optional: false]}], "hexpm", "501133f3112079b92d9e22da8b88bf4f0e13d4d67ae9c15c42c30bd25ceb83b6"},
   "elixir_make": {:hex, :elixir_make, "0.6.0", "38349f3e29aff4864352084fc736fa7fa0f2995a819a737554f7ebd28b85aaab", [:mix], [], "hexpm", "d522695b93b7f0b4c0fcb2dfe73a6b905b1c301226a5a55cb42e5b14d509e050"},
   "esshd": {:hex, :esshd, "0.1.1", "d4dd4c46698093a40a56afecce8a46e246eb35463c457c246dacba2e056f31b5", [:mix], [], "hexpm", "d73e341e3009d390aa36387dc8862860bf9f874c94d9fd92ade2926376f49981"},
   "eternal": {:hex, :eternal, "1.2.1", "d5b6b2499ba876c57be2581b5b999ee9bdf861c647401066d3eeed111d096bc4", [:mix], [], "hexpm", "b14f1dc204321429479c569cfbe8fb287541184ed040956c8862cb7a677b8406"},
@@ -80,6 +81,7 @@
   "nodex": {:git, "https://git.pleroma.social/pleroma/nodex", "cb6730f943cfc6aad674c92161be23a8411f15d1", [ref: "cb6730f943cfc6aad674c92161be23a8411f15d1"]},
   "oban": {:hex, :oban, "2.0.0", "e6ce70d94dd46815ec0882a1ffb7356df9a9d5b8a40a64ce5c2536617a447379", [:mix], [{:ecto_sql, ">= 3.4.3", [hex: :ecto_sql, repo: "hexpm", optional: false]}, {:jason, "~> 1.1", [hex: :jason, repo: "hexpm", optional: false]}, {:postgrex, "~> 0.14", [hex: :postgrex, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "cf574813bd048b98a698aa587c21367d2e06842d4e1b1993dcd6a696e9e633bd"},
   "open_api_spex": {:git, "https://git.pleroma.social/pleroma/elixir-libraries/open_api_spex.git", "f296ac0924ba3cf79c7a588c4c252889df4c2edd", [ref: "f296ac0924ba3cf79c7a588c4c252889df4c2edd"]},
+  "p1_utils": {:hex, :p1_utils, "1.0.18", "3fe224de5b2e190d730a3c5da9d6e8540c96484cf4b4692921d1e28f0c32b01c", [:rebar3], [], "hexpm", "1fc8773a71a15553b179c986b22fbeead19b28fe486c332d4929700ffeb71f88"},
   "parse_trans": {:hex, :parse_trans, "3.3.0", "09765507a3c7590a784615cfd421d101aec25098d50b89d7aa1d66646bc571c1", [:rebar3], [], "hexpm", "17ef63abde837ad30680ea7f857dd9e7ced9476cdd7b0394432af4bfc241b960"},
   "pbkdf2_elixir": {:hex, :pbkdf2_elixir, "1.2.1", "9cbe354b58121075bd20eb83076900a3832324b7dd171a6895fab57b6bb2752c", [:mix], [{:comeonin, "~> 5.3", [hex: :comeonin, repo: "hexpm", optional: false]}], "hexpm", "d3b40a4a4630f0b442f19eca891fcfeeee4c40871936fed2f68e1c4faa30481f"},
   "phoenix": {:hex, :phoenix, "1.4.17", "1b1bd4cff7cfc87c94deaa7d60dd8c22e04368ab95499483c50640ef3bd838d8", [:mix], [{:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 1.1", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}, {:plug, "~> 1.8.1 or ~> 1.9", [hex: :plug, repo: "hexpm", optional: false]}, {:plug_cowboy, "~> 1.0 or ~> 2.0", [hex: :plug_cowboy, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "3a8e5d7a3d76d452bb5fb86e8b7bd115f737e4f8efe202a463d4aeb4a5809611"},
@@ -118,5 +120,5 @@
   "unicode_util_compat": {:hex, :unicode_util_compat, "0.4.1", "d869e4c68901dd9531385bb0c8c40444ebf624e60b6962d95952775cac5e90cd", [:rebar3], [], "hexpm", "1d1848c40487cdb0b30e8ed975e34e025860c02e419cb615d255849f3427439d"},
   "unsafe": {:hex, :unsafe, "1.0.1", "a27e1874f72ee49312e0a9ec2e0b27924214a05e3ddac90e91727bc76f8613d8", [:mix], [], "hexpm", "6c7729a2d214806450d29766abc2afaa7a2cbecf415be64f36a6691afebb50e5"},
   "web_push_encryption": {:hex, :web_push_encryption, "0.3.0", "598b5135e696fd1404dc8d0d7c0fa2c027244a4e5d5e5a98ba267f14fdeaabc8", [:mix], [{:httpoison, "~> 1.0", [hex: :httpoison, repo: "hexpm", optional: false]}, {:jose, "~> 1.8", [hex: :jose, repo: "hexpm", optional: false]}], "hexpm", "f10bdd1afe527ede694749fb77a2f22f146a51b054c7fa541c9fd920fba7c875"},
-  "websocket_client": {:git, "https://github.com/jeremyong/websocket_client.git", "9a6f65d05ebf2725d62fb19262b21f1805a59fbf", []},
+  "websocket_client": {:git, "https://github.com/jeremyong/websocket_client.git", "9a6f65d05ebf2725d62fb19262b21f1805a59fbf", []}
 }
diff --git a/test/fixtures/image.gif b/test/fixtures/image.gif
new file mode 100755
index 000000000..9df64778b
--- /dev/null
+++ b/test/fixtures/image.gif
diff --git a/test/fixtures/image.png b/test/fixtures/image.png
new file mode 100755
index 000000000..e999e8800
--- /dev/null
+++ b/test/fixtures/image.png
diff --git a/test/web/activity_pub/mrf/mediaproxy_warming_policy_test.exs b/test/web/activity_pub/mrf/mediaproxy_warming_policy_test.exs
index 313d59a66..1710c4d2a 100644
--- a/test/web/activity_pub/mrf/mediaproxy_warming_policy_test.exs
+++ b/test/web/activity_pub/mrf/mediaproxy_warming_policy_test.exs
@@ -22,6 +22,8 @@ defmodule Pleroma.Web.ActivityPub.MRF.MediaProxyWarmingPolicyTest do
     }
   }
 
+  setup do: clear_config([:media_proxy, :enabled], true)
+
   test "it prefetches media proxy URIs" do
     with_mock HTTP, get: fn _, _, _ -> {:ok, []} end do
       MediaProxyWarmingPolicy.filter(@message)
diff --git a/test/web/fed_sockets/fed_registry_test.exs b/test/web/fed_sockets/fed_registry_test.exs
new file mode 100644
index 000000000..19ac874d6
--- /dev/null
+++ b/test/web/fed_sockets/fed_registry_test.exs
@@ -0,0 +1,124 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.FedSockets.FedRegistryTest do
+  use ExUnit.Case
+
+  alias Pleroma.Web.FedSockets
+  alias Pleroma.Web.FedSockets.FedRegistry
+  alias Pleroma.Web.FedSockets.SocketInfo
+
+  @good_domain "http://good.domain"
+  @good_domain_origin "good.domain:80"
+
+  setup do
+    start_supervised({Pleroma.Web.FedSockets.Supervisor, []})
+    build_test_socket(@good_domain)
+    Process.sleep(10)
+
+    :ok
+  end
+
+  describe "add_fed_socket/1 without conflicting sockets" do
+    test "can be added" do
+      Process.sleep(10)
+      assert {:ok, %SocketInfo{origin: origin}} = FedRegistry.get_fed_socket(@good_domain_origin)
+      assert origin == "good.domain:80"
+    end
+
+    test "multiple origins can be added" do
+      build_test_socket("http://anothergood.domain")
+      Process.sleep(10)
+
+      assert {:ok, %SocketInfo{origin: origin_1}} =
+               FedRegistry.get_fed_socket(@good_domain_origin)
+
+      assert {:ok, %SocketInfo{origin: origin_2}} =
+               FedRegistry.get_fed_socket("anothergood.domain:80")
+
+      assert origin_1 == "good.domain:80"
+      assert origin_2 == "anothergood.domain:80"
+      assert FedRegistry.list_all() |> Enum.count() == 2
+    end
+  end
+
+  describe "add_fed_socket/1 when duplicate sockets conflict" do
+    setup do
+      build_test_socket(@good_domain)
+      build_test_socket(@good_domain)
+      Process.sleep(10)
+      :ok
+    end
+
+    test "will be ignored" do
+      assert {:ok, %SocketInfo{origin: origin, pid: pid_one}} =
+               FedRegistry.get_fed_socket(@good_domain_origin)
+
+      assert origin == "good.domain:80"
+
+      assert FedRegistry.list_all() |> Enum.count() == 1
+    end
+
+    test "the newer process will be closed" do
+      pid_two = build_test_socket(@good_domain)
+
+      assert {:ok, %SocketInfo{origin: origin, pid: pid_one}} =
+               FedRegistry.get_fed_socket(@good_domain_origin)
+
+      assert origin == "good.domain:80"
+      Process.sleep(10)
+
+      refute Process.alive?(pid_two)
+
+      assert FedRegistry.list_all() |> Enum.count() == 1
+    end
+  end
+
+  describe "get_fed_socket/1" do
+    test "returns missing for unknown hosts" do
+      assert {:error, :missing} = FedRegistry.get_fed_socket("not_a_dmoain")
+    end
+
+    test "returns rejected for hosts previously rejected" do
+      "rejected.domain:80"
+      |> FedSockets.uri_for_origin()
+      |> FedRegistry.set_host_rejected()
+
+      assert {:error, :rejected} = FedRegistry.get_fed_socket("rejected.domain:80")
+    end
+
+    test "can retrieve a previously added SocketInfo" do
+      build_test_socket(@good_domain)
+      Process.sleep(10)
+      assert {:ok, %SocketInfo{origin: origin}} = FedRegistry.get_fed_socket(@good_domain_origin)
+      assert origin == "good.domain:80"
+    end
+
+    test "removes references to SocketInfos when the process crashes" do
+      assert {:ok, %SocketInfo{origin: origin, pid: pid}} =
+               FedRegistry.get_fed_socket(@good_domain_origin)
+
+      assert origin == "good.domain:80"
+
+      Process.exit(pid, :testing)
+      Process.sleep(100)
+      assert {:error, :missing} = FedRegistry.get_fed_socket(@good_domain_origin)
+    end
+  end
+
+  def build_test_socket(uri) do
+    Kernel.spawn(fn -> fed_socket_almost(uri) end)
+  end
+
+  def fed_socket_almost(origin) do
+    FedRegistry.add_fed_socket(origin)
+
+    receive do
+      :close ->
+        :ok
+    after
+      5_000 -> :timeout
+    end
+  end
+end
diff --git a/test/web/fed_sockets/fetch_registry_test.exs b/test/web/fed_sockets/fetch_registry_test.exs
new file mode 100644
index 000000000..7bd2d995a
--- /dev/null
+++ b/test/web/fed_sockets/fetch_registry_test.exs
@@ -0,0 +1,67 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.FedSockets.FetchRegistryTest do
+  use ExUnit.Case
+
+  alias Pleroma.Web.FedSockets.FetchRegistry
+  alias Pleroma.Web.FedSockets.FetchRegistry.FetchRegistryData
+
+  @json_message "hello"
+  @json_reply "hello back"
+
+  setup do
+    start_supervised(
+      {Pleroma.Web.FedSockets.Supervisor,
+       [
+         ping_interval: 8,
+         connection_duration: 15,
+         rejection_duration: 5,
+         fed_socket_fetches: [default: 10, interval: 10]
+       ]}
+    )
+
+    :ok
+  end
+
+  test "fetches can be stored" do
+    uuid = FetchRegistry.register_fetch(@json_message)
+
+    assert {:error, :waiting} = FetchRegistry.check_fetch(uuid)
+  end
+
+  test "fetches can return" do
+    uuid = FetchRegistry.register_fetch(@json_message)
+    task = Task.async(fn -> FetchRegistry.register_fetch_received(uuid, @json_reply) end)
+
+    assert {:error, :waiting} = FetchRegistry.check_fetch(uuid)
+    Task.await(task)
+
+    assert {:ok, %FetchRegistryData{received_json: received_json}} =
+             FetchRegistry.check_fetch(uuid)
+
+    assert received_json == @json_reply
+  end
+
+  test "fetches are deleted once popped from stack" do
+    uuid = FetchRegistry.register_fetch(@json_message)
+    task = Task.async(fn -> FetchRegistry.register_fetch_received(uuid, @json_reply) end)
+    Task.await(task)
+
+    assert {:ok, %FetchRegistryData{received_json: received_json}} =
+             FetchRegistry.check_fetch(uuid)
+
+    assert received_json == @json_reply
+    assert {:ok, @json_reply} = FetchRegistry.pop_fetch(uuid)
+
+    assert {:error, :missing} = FetchRegistry.check_fetch(uuid)
+  end
+
+  test "fetches can time out" do
+    uuid = FetchRegistry.register_fetch(@json_message)
+    assert {:error, :waiting} = FetchRegistry.check_fetch(uuid)
+    Process.sleep(500)
+    assert {:error, :missing} = FetchRegistry.check_fetch(uuid)
+  end
+end
diff --git a/test/web/fed_sockets/socket_info_test.exs b/test/web/fed_sockets/socket_info_test.exs
new file mode 100644
index 000000000..db3d6edcd
--- /dev/null
+++ b/test/web/fed_sockets/socket_info_test.exs
@@ -0,0 +1,118 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.FedSockets.SocketInfoTest do
+  use ExUnit.Case
+
+  alias Pleroma.Web.FedSockets
+  alias Pleroma.Web.FedSockets.SocketInfo
+
+  describe "uri_for_origin" do
+    test "provides the fed_socket URL given the origin information" do
+      endpoint = "example.com:4000"
+      assert FedSockets.uri_for_origin(endpoint) =~ "ws://"
+      assert FedSockets.uri_for_origin(endpoint) =~ endpoint
+    end
+  end
+
+  describe "origin" do
+    test "will provide the origin field given a url" do
+      endpoint = "example.com:4000"
+      assert SocketInfo.origin("ws://#{endpoint}") == endpoint
+      assert SocketInfo.origin("http://#{endpoint}") == endpoint
+      assert SocketInfo.origin("https://#{endpoint}") == endpoint
+    end
+
+    test "will proide the origin field given a uri" do
+      endpoint = "example.com:4000"
+      uri = URI.parse("http://#{endpoint}")
+
+      assert SocketInfo.origin(uri) == endpoint
+    end
+  end
+
+  describe "touch" do
+    test "will update the TTL" do
+      endpoint = "example.com:4000"
+      socket = SocketInfo.build("ws://#{endpoint}")
+      Process.sleep(2)
+      touched_socket = SocketInfo.touch(socket)
+
+      assert socket.connected_until < touched_socket.connected_until
+    end
+  end
+
+  describe "expired?" do
+    setup do
+      start_supervised(
+        {Pleroma.Web.FedSockets.Supervisor,
+         [
+           ping_interval: 8,
+           connection_duration: 5,
+           rejection_duration: 5,
+           fed_socket_rejections: [lazy: true]
+         ]}
+      )
+
+      :ok
+    end
+
+    test "tests if the TTL is exceeded" do
+      endpoint = "example.com:4000"
+      socket = SocketInfo.build("ws://#{endpoint}")
+      refute SocketInfo.expired?(socket)
+      Process.sleep(10)
+
+      assert SocketInfo.expired?(socket)
+    end
+  end
+
+  describe "creating outgoing connection records" do
+    test "can be passed a string" do
+      assert %{conn_pid: :pid, origin: _origin} = SocketInfo.build("example.com:4000", :pid)
+    end
+
+    test "can be passed a URI" do
+      uri = URI.parse("http://example.com:4000")
+      assert %{conn_pid: :pid, origin: origin} = SocketInfo.build(uri, :pid)
+      assert origin =~ "example.com:4000"
+    end
+
+    test "will include the port number" do
+      assert %{conn_pid: :pid, origin: origin} = SocketInfo.build("http://example.com:4000", :pid)
+
+      assert origin =~ ":4000"
+    end
+
+    test "will provide the port if missing" do
+      assert %{conn_pid: :pid, origin: "example.com:80"} =
+               SocketInfo.build("http://example.com", :pid)
+
+      assert %{conn_pid: :pid, origin: "example.com:443"} =
+               SocketInfo.build("https://example.com", :pid)
+    end
+  end
+
+  describe "creating incoming connection records" do
+    test "can be passed a string" do
+      assert %{pid: _, origin: _origin} = SocketInfo.build("example.com:4000")
+    end
+
+    test "can be passed a URI" do
+      uri = URI.parse("example.com:4000")
+      assert %{pid: _, origin: _origin} = SocketInfo.build(uri)
+    end
+
+    test "will include the port number" do
+      assert %{pid: _, origin: origin} = SocketInfo.build("http://example.com:4000")
+
+      assert origin =~ ":4000"
+    end
+
+    test "will provide the port if missing" do
+      assert %{pid: _, origin: "example.com:80"} = SocketInfo.build("http://example.com")
+      assert %{pid: _, origin: "example.com:443"} = SocketInfo.build("https://example.com")
+    end
+  end
+end
diff --git a/test/web/mastodon_api/views/account_view_test.exs b/test/web/mastodon_api/views/account_view_test.exs
index a54b765ef..a5f39b215 100644
--- a/test/web/mastodon_api/views/account_view_test.exs
+++ b/test/web/mastodon_api/views/account_view_test.exs
@@ -5,6 +5,7 @@
 defmodule Pleroma.Web.MastodonAPI.AccountViewTest do
   use Pleroma.DataCase
 
+  alias Pleroma.Config
   alias Pleroma.User
   alias Pleroma.UserRelationship
   alias Pleroma.Web.CommonAPI
@@ -540,8 +541,9 @@ defmodule Pleroma.Web.MastodonAPI.AccountViewTest do
     end
   end
 
-  test "uses mediaproxy urls when it's enabled" do
+  test "uses mediaproxy urls when it's enabled (regardless of media preview proxy state)" do
     clear_config([:media_proxy, :enabled], true)
+    clear_config([:media_preview_proxy, :enabled])
 
     user =
       insert(:user,
@@ -550,20 +552,24 @@ defmodule Pleroma.Web.MastodonAPI.AccountViewTest do
         emoji: %{"joker_smile" => "https://evil.website/society.png"}
       )
 
-    AccountView.render("show.json", %{user: user, skip_visibility_check: true})
-    |> Enum.all?(fn
-      {key, url} when key in [:avatar, :avatar_static, :header, :header_static] ->
-        String.starts_with?(url, Pleroma.Web.base_url())
-
-      {:emojis, emojis} ->
-        Enum.all?(emojis, fn %{url: url, static_url: static_url} ->
-          String.starts_with?(url, Pleroma.Web.base_url()) &&
-            String.starts_with?(static_url, Pleroma.Web.base_url())
-        end)
-
-      _ ->
-        true
-    end)
-    |> assert()
+    with media_preview_enabled <- [false, true] do
+      Config.put([:media_preview_proxy, :enabled], media_preview_enabled)
+
+      AccountView.render("show.json", %{user: user, skip_visibility_check: true})
+      |> Enum.all?(fn
+        {key, url} when key in [:avatar, :avatar_static, :header, :header_static] ->
+          String.starts_with?(url, Pleroma.Web.base_url())
+
+        {:emojis, emojis} ->
+          Enum.all?(emojis, fn %{url: url, static_url: static_url} ->
+            String.starts_with?(url, Pleroma.Web.base_url()) &&
+              String.starts_with?(static_url, Pleroma.Web.base_url())
+          end)
+
+        _ ->
+          true
+      end)
+      |> assert()
+    end
   end
 end
diff --git a/test/web/media_proxy/media_proxy_controller_test.exs b/test/web/media_proxy/media_proxy_controller_test.exs
index d4db44c63..33e6873f7 100644
--- a/test/web/media_proxy/media_proxy_controller_test.exs
+++ b/test/web/media_proxy/media_proxy_controller_test.exs
@@ -8,34 +8,34 @@ defmodule Pleroma.Web.MediaProxy.MediaProxyControllerTest do
   import Mock
 
   alias Pleroma.Web.MediaProxy
-  alias Pleroma.Web.MediaProxy.MediaProxyController
   alias Plug.Conn
 
   setup do
     on_exit(fn -> Cachex.clear(:banned_urls_cache) end)
   end
 
-  test "it returns 404 when MediaProxy disabled", %{conn: conn} do
-    clear_config([:media_proxy, :enabled], false)
-
-    assert %Conn{
-             status: 404,
-             resp_body: "Not Found"
-           } = get(conn, "/proxy/hhgfh/eeeee")
-
-    assert %Conn{
-             status: 404,
-             resp_body: "Not Found"
-           } = get(conn, "/proxy/hhgfh/eeee/fff")
-  end
-
-  describe "" do
+  describe "Media Proxy" do
     setup do
       clear_config([:media_proxy, :enabled], true)
       clear_config([Pleroma.Web.Endpoint, :secret_key_base], "00000000000")
+
       [url: MediaProxy.encode_url("https://google.fn/test.png")]
     end
 
+    test "it returns 404 when disabled", %{conn: conn} do
+      clear_config([:media_proxy, :enabled], false)
+
+      assert %Conn{
+               status: 404,
+               resp_body: "Not Found"
+             } = get(conn, "/proxy/hhgfh/eeeee")
+
+      assert %Conn{
+               status: 404,
+               resp_body: "Not Found"
+             } = get(conn, "/proxy/hhgfh/eeee/fff")
+    end
+
     test "it returns 403 for invalid signature", %{conn: conn, url: url} do
       Pleroma.Config.put([Pleroma.Web.Endpoint, :secret_key_base], "000")
       %{path: path} = URI.parse(url)
@@ -56,7 +56,7 @@ defmodule Pleroma.Web.MediaProxy.MediaProxyControllerTest do
              } = get(conn, "/proxy/hhgfh/eeee/fff")
     end
 
-    test "redirects on valid url when filename is invalidated", %{conn: conn, url: url} do
+    test "redirects to valid url when filename is invalidated", %{conn: conn, url: url} do
       invalid_url = String.replace(url, "test.png", "test-file.png")
       response = get(conn, invalid_url)
       assert response.status == 302
@@ -80,42 +80,248 @@ defmodule Pleroma.Web.MediaProxy.MediaProxyControllerTest do
     end
   end
 
-  describe "filename_matches/3" do
-    test "preserves the encoded or decoded path" do
-      assert MediaProxyController.filename_matches(
-               %{"filename" => "/Hello world.jpg"},
-               "/Hello world.jpg",
-               "http://pleroma.social/Hello world.jpg"
-             ) == :ok
-
-      assert MediaProxyController.filename_matches(
-               %{"filename" => "/Hello%20world.jpg"},
-               "/Hello%20world.jpg",
-               "http://pleroma.social/Hello%20world.jpg"
-             ) == :ok
-
-      assert MediaProxyController.filename_matches(
-               %{"filename" => "/my%2Flong%2Furl%2F2019%2F07%2FS.jpg"},
-               "/my%2Flong%2Furl%2F2019%2F07%2FS.jpg",
-               "http://pleroma.social/my%2Flong%2Furl%2F2019%2F07%2FS.jpg"
-             ) == :ok
-
-      assert MediaProxyController.filename_matches(
-               %{"filename" => "/my%2Flong%2Furl%2F2019%2F07%2FS.jp"},
-               "/my%2Flong%2Furl%2F2019%2F07%2FS.jp",
-               "http://pleroma.social/my%2Flong%2Furl%2F2019%2F07%2FS.jpg"
-             ) == {:wrong_filename, "my%2Flong%2Furl%2F2019%2F07%2FS.jpg"}
-    end
-
-    test "encoded url are tried to match for proxy as `conn.request_path` encodes the url" do
-      # conn.request_path will return encoded url
-      request_path = "/ANALYSE-DAI-_-LE-STABLECOIN-100-D%C3%89CENTRALIS%C3%89-BQ.jpg"
-
-      assert MediaProxyController.filename_matches(
-               true,
-               request_path,
-               "https://mydomain.com/uploads/2019/07/ANALYSE-DAI-_-LE-STABLECOIN-100-DÉCENTRALISÉ-BQ.jpg"
-             ) == :ok
+  describe "Media Preview Proxy" do
+    setup do
+      clear_config([:media_proxy, :enabled], true)
+      clear_config([:media_preview_proxy, :enabled], true)
+      clear_config([Pleroma.Web.Endpoint, :secret_key_base], "00000000000")
+
+      original_url = "https://google.fn/test.png"
+
+      [
+        url: MediaProxy.encode_preview_url(original_url),
+        media_proxy_url: MediaProxy.encode_url(original_url)
+      ]
+    end
+
+    test "returns 404 when media proxy is disabled", %{conn: conn} do
+      clear_config([:media_proxy, :enabled], false)
+
+      assert %Conn{
+               status: 404,
+               resp_body: "Not Found"
+             } = get(conn, "/proxy/preview/hhgfh/eeeee")
+
+      assert %Conn{
+               status: 404,
+               resp_body: "Not Found"
+             } = get(conn, "/proxy/preview/hhgfh/fff")
+    end
+
+    test "returns 404 when disabled", %{conn: conn} do
+      clear_config([:media_preview_proxy, :enabled], false)
+
+      assert %Conn{
+               status: 404,
+               resp_body: "Not Found"
+             } = get(conn, "/proxy/preview/hhgfh/eeeee")
+
+      assert %Conn{
+               status: 404,
+               resp_body: "Not Found"
+             } = get(conn, "/proxy/preview/hhgfh/fff")
+    end
+
+    test "it returns 403 for invalid signature", %{conn: conn, url: url} do
+      Pleroma.Config.put([Pleroma.Web.Endpoint, :secret_key_base], "000")
+      %{path: path} = URI.parse(url)
+
+      assert %Conn{
+               status: 403,
+               resp_body: "Forbidden"
+             } = get(conn, path)
+
+      assert %Conn{
+               status: 403,
+               resp_body: "Forbidden"
+             } = get(conn, "/proxy/preview/hhgfh/eeee")
+
+      assert %Conn{
+               status: 403,
+               resp_body: "Forbidden"
+             } = get(conn, "/proxy/preview/hhgfh/eeee/fff")
+    end
+
+    test "redirects to valid url when filename is invalidated", %{conn: conn, url: url} do
+      invalid_url = String.replace(url, "test.png", "test-file.png")
+      response = get(conn, invalid_url)
+      assert response.status == 302
+      assert redirected_to(response) == url
+    end
+
+    test "responds with 424 Failed Dependency if HEAD request to media proxy fails", %{
+      conn: conn,
+      url: url,
+      media_proxy_url: media_proxy_url
+    } do
+      Tesla.Mock.mock(fn
+        %{method: "head", url: ^media_proxy_url} ->
+          %Tesla.Env{status: 500, body: ""}
+      end)
+
+      response = get(conn, url)
+      assert response.status == 424
+      assert response.resp_body == "Can't fetch HTTP headers (HTTP 500)."
+    end
+
+    test "redirects to media proxy URI on unsupported content type", %{
+      conn: conn,
+      url: url,
+      media_proxy_url: media_proxy_url
+    } do
+      Tesla.Mock.mock(fn
+        %{method: "head", url: ^media_proxy_url} ->
+          %Tesla.Env{status: 200, body: "", headers: [{"content-type", "application/pdf"}]}
+      end)
+
+      response = get(conn, url)
+      assert response.status == 302
+      assert redirected_to(response) == media_proxy_url
+    end
+
+    test "with `static=true` and GIF image preview requested, responds with JPEG image", %{
+      conn: conn,
+      url: url,
+      media_proxy_url: media_proxy_url
+    } do
+      # Setting a high :min_content_length to ensure this scenario is not affected by its logic
+      clear_config([:media_preview_proxy, :min_content_length], 1_000_000_000)
+
+      Tesla.Mock.mock(fn
+        %{method: "head", url: ^media_proxy_url} ->
+          %Tesla.Env{
+            status: 200,
+            body: "",
+            headers: [{"content-type", "image/gif"}, {"content-length", "1001718"}]
+          }
+
+        %{method: :get, url: ^media_proxy_url} ->
+          %Tesla.Env{status: 200, body: File.read!("test/fixtures/image.gif")}
+      end)
+
+      response = get(conn, url <> "?static=true")
+
+      assert response.status == 200
+      assert Conn.get_resp_header(response, "content-type") == ["image/jpeg"]
+      assert response.resp_body != ""
+    end
+
+    test "with GIF image preview requested and no `static` param, redirects to media proxy URI",
+         %{
+           conn: conn,
+           url: url,
+           media_proxy_url: media_proxy_url
+         } do
+      Tesla.Mock.mock(fn
+        %{method: "head", url: ^media_proxy_url} ->
+          %Tesla.Env{status: 200, body: "", headers: [{"content-type", "image/gif"}]}
+      end)
+
+      response = get(conn, url)
+
+      assert response.status == 302
+      assert redirected_to(response) == media_proxy_url
+    end
+
+    test "with `static` param and non-GIF image preview requested, " <>
+           "redirects to media preview proxy URI without `static` param",
+         %{
+           conn: conn,
+           url: url,
+           media_proxy_url: media_proxy_url
+         } do
+      Tesla.Mock.mock(fn
+        %{method: "head", url: ^media_proxy_url} ->
+          %Tesla.Env{status: 200, body: "", headers: [{"content-type", "image/jpeg"}]}
+      end)
+
+      response = get(conn, url <> "?static=true")
+
+      assert response.status == 302
+      assert redirected_to(response) == url
+    end
+
+    test "with :min_content_length setting not matched by Content-Length header, " <>
+           "redirects to media proxy URI",
+         %{
+           conn: conn,
+           url: url,
+           media_proxy_url: media_proxy_url
+         } do
+      clear_config([:media_preview_proxy, :min_content_length], 100_000)
+
+      Tesla.Mock.mock(fn
+        %{method: "head", url: ^media_proxy_url} ->
+          %Tesla.Env{
+            status: 200,
+            body: "",
+            headers: [{"content-type", "image/gif"}, {"content-length", "5000"}]
+          }
+      end)
+
+      response = get(conn, url)
+
+      assert response.status == 302
+      assert redirected_to(response) == media_proxy_url
+    end
+
+    test "thumbnails PNG images into PNG", %{
+      conn: conn,
+      url: url,
+      media_proxy_url: media_proxy_url
+    } do
+      Tesla.Mock.mock(fn
+        %{method: "head", url: ^media_proxy_url} ->
+          %Tesla.Env{status: 200, body: "", headers: [{"content-type", "image/png"}]}
+
+        %{method: :get, url: ^media_proxy_url} ->
+          %Tesla.Env{status: 200, body: File.read!("test/fixtures/image.png")}
+      end)
+
+      response = get(conn, url)
+
+      assert response.status == 200
+      assert Conn.get_resp_header(response, "content-type") == ["image/png"]
+      assert response.resp_body != ""
+    end
+
+    test "thumbnails JPEG images into JPEG", %{
+      conn: conn,
+      url: url,
+      media_proxy_url: media_proxy_url
+    } do
+      Tesla.Mock.mock(fn
+        %{method: "head", url: ^media_proxy_url} ->
+          %Tesla.Env{status: 200, body: "", headers: [{"content-type", "image/jpeg"}]}
+
+        %{method: :get, url: ^media_proxy_url} ->
+          %Tesla.Env{status: 200, body: File.read!("test/fixtures/image.jpg")}
+      end)
+
+      response = get(conn, url)
+
+      assert response.status == 200
+      assert Conn.get_resp_header(response, "content-type") == ["image/jpeg"]
+      assert response.resp_body != ""
+    end
+
+    test "redirects to media proxy URI in case of thumbnailing error", %{
+      conn: conn,
+      url: url,
+      media_proxy_url: media_proxy_url
+    } do
+      Tesla.Mock.mock(fn
+        %{method: "head", url: ^media_proxy_url} ->
+          %Tesla.Env{status: 200, body: "", headers: [{"content-type", "image/jpeg"}]}
+
+        %{method: :get, url: ^media_proxy_url} ->
+          %Tesla.Env{status: 200, body: "<html><body>error</body></html>"}
+      end)
+
+      response = get(conn, url)
+
+      assert response.status == 302
+      assert redirected_to(response) == media_proxy_url
     end
   end
 end
diff --git a/test/web/media_proxy/media_proxy_test.exs b/test/web/media_proxy/media_proxy_test.exs
index 72885cfdd..0e6df826c 100644
--- a/test/web/media_proxy/media_proxy_test.exs
+++ b/test/web/media_proxy/media_proxy_test.exs
@@ -6,9 +6,16 @@ defmodule Pleroma.Web.MediaProxyTest do
   use ExUnit.Case
   use Pleroma.Tests.Helpers
 
+  alias Pleroma.Config
   alias Pleroma.Web.Endpoint
   alias Pleroma.Web.MediaProxy
 
+  defp decode_result(encoded) do
+    [_, "proxy", sig, base64 | _] = URI.parse(encoded).path |> String.split("/")
+    {:ok, decoded} = MediaProxy.decode_url(sig, base64)
+    decoded
+  end
+
   describe "when enabled" do
     setup do: clear_config([:media_proxy, :enabled], true)
 
@@ -35,7 +42,7 @@ defmodule Pleroma.Web.MediaProxyTest do
 
       assert String.starts_with?(
                encoded,
-               Pleroma.Config.get([:media_proxy, :base_url], Pleroma.Web.base_url())
+               Config.get([:media_proxy, :base_url], Pleroma.Web.base_url())
              )
 
       assert String.ends_with?(encoded, "/logo.png")
@@ -75,6 +82,64 @@ defmodule Pleroma.Web.MediaProxyTest do
       assert MediaProxy.decode_url(sig, base64) == {:error, :invalid_signature}
     end
 
+    def test_verify_request_path_and_url(request_path, url, expected_result) do
+      assert MediaProxy.verify_request_path_and_url(request_path, url) == expected_result
+
+      assert MediaProxy.verify_request_path_and_url(
+               %Plug.Conn{
+                 params: %{"filename" => Path.basename(request_path)},
+                 request_path: request_path
+               },
+               url
+             ) == expected_result
+    end
+
+    test "if first arg of `verify_request_path_and_url/2` is a Plug.Conn without \"filename\" " <>
+           "parameter, `verify_request_path_and_url/2` returns :ok " do
+      assert MediaProxy.verify_request_path_and_url(
+               %Plug.Conn{params: %{}, request_path: "/some/path"},
+               "https://instance.com/file.jpg"
+             ) == :ok
+
+      assert MediaProxy.verify_request_path_and_url(
+               %Plug.Conn{params: %{}, request_path: "/path/to/file.jpg"},
+               "https://instance.com/file.jpg"
+             ) == :ok
+    end
+
+    test "`verify_request_path_and_url/2` preserves the encoded or decoded path" do
+      test_verify_request_path_and_url(
+        "/Hello world.jpg",
+        "http://pleroma.social/Hello world.jpg",
+        :ok
+      )
+
+      test_verify_request_path_and_url(
+        "/Hello%20world.jpg",
+        "http://pleroma.social/Hello%20world.jpg",
+        :ok
+      )
+
+      test_verify_request_path_and_url(
+        "/my%2Flong%2Furl%2F2019%2F07%2FS.jpg",
+        "http://pleroma.social/my%2Flong%2Furl%2F2019%2F07%2FS.jpg",
+        :ok
+      )
+
+      test_verify_request_path_and_url(
+        # Note: `conn.request_path` returns encoded url
+        "/ANALYSE-DAI-_-LE-STABLECOIN-100-D%C3%89CENTRALIS%C3%89-BQ.jpg",
+        "https://mydomain.com/uploads/2019/07/ANALYSE-DAI-_-LE-STABLECOIN-100-DÉCENTRALISÉ-BQ.jpg",
+        :ok
+      )
+
+      test_verify_request_path_and_url(
+        "/my%2Flong%2Furl%2F2019%2F07%2FS",
+        "http://pleroma.social/my%2Flong%2Furl%2F2019%2F07%2FS.jpg",
+        {:wrong_filename, "my%2Flong%2Furl%2F2019%2F07%2FS.jpg"}
+      )
+    end
+
     test "uses the configured base_url" do
       base_url = "https://cache.pleroma.social"
       clear_config([:media_proxy, :base_url], base_url)
@@ -124,12 +189,6 @@ defmodule Pleroma.Web.MediaProxyTest do
     end
   end
 
-  defp decode_result(encoded) do
-    [_, "proxy", sig, base64 | _] = URI.parse(encoded).path |> String.split("/")
-    {:ok, decoded} = MediaProxy.decode_url(sig, base64)
-    decoded
-  end
-
   describe "whitelist" do
     setup do: clear_config([:media_proxy, :enabled], true)
 
diff --git a/test/web/push/impl_test.exs b/test/web/push/impl_test.exs
index aeb5c1fbd..c7c17e156 100644
--- a/test/web/push/impl_test.exs
+++ b/test/web/push/impl_test.exs
@@ -12,7 +12,9 @@ defmodule Pleroma.Web.Push.ImplTest do
   alias Pleroma.Web.CommonAPI
   alias Pleroma.Web.Push.Impl
   alias Pleroma.Web.Push.Subscription
+  alias Pleroma.Web.WebPushHttpClientMock
 
+  import Mock
   import Pleroma.Factory
 
   setup do
@@ -78,6 +80,22 @@ defmodule Pleroma.Web.Push.ImplTest do
     assert Impl.push_message(@message, @sub, @api_key, %Subscription{}) == :ok
   end
 
+  test_with_mock "uses WebPushHttpClientMock as an HTTP client", WebPushHttpClientMock,
+    post: fn _, _, _ -> {:ok, %{status_code: 200}} end do
+    Impl.push_message(@message, @sub, @api_key, %Subscription{})
+    assert_called(WebPushHttpClientMock.post("https://example.com/example/1234", :_, :_))
+  end
+
+  test_with_mock "uses Pleroma.HTTP as an HTTP client", Pleroma.HTTP,
+    post: fn _, _, _ -> {:ok, %{status_code: 200}} end do
+    client = Application.get_env(:web_push_encryption, :http_client)
+    on_exit(fn -> Application.put_env(:web_push_encryption, :http_client, client) end)
+    Application.put_env(:web_push_encryption, :http_client, Pleroma.HTTP)
+
+    Impl.push_message(@message, @sub, @api_key, %Subscription{})
+    assert_called(Pleroma.HTTP.post("https://example.com/example/1234", :_, :_))
+  end
+
   @tag capture_log: true
   test "fail message sending" do
     assert Impl.push_message(