3 files changed, 46 insertions, 7 deletions
diff --git a/lib/pleroma/upload/filter/exiftool.ex b/lib/pleroma/upload/filter/exiftool.ex
new file mode 100644
index 000000000..ea8798fe3
--- /dev/null
+++ b/lib/pleroma/upload/filter/exiftool.ex
@@ -0,0 +1,26 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Upload.Filter.Exiftool do
+  @moduledoc """
+  Strips GPS related EXIF tags and overwrites the file in place.
+  Also strips or replaces filesystem metadata e.g., timestamps.
+  """
+  @behaviour Pleroma.Upload.Filter
+
+  @spec filter(Pleroma.Upload.t()) :: :ok | {:error, String.t()}
+  def filter(%Pleroma.Upload{tempfile: file, content_type: "image" <> _}) do
+    try do
+      case System.cmd("exiftool", ["-overwrite_original", "-gps:all=", file], parallelism: true) do
+        {_response, 0} -> :ok
+        {error, 1} -> {:error, error}
+      end
+    rescue
+      _e in ErlangError ->
+        {:error, "exiftool command not found"}
+    end
+  end
+
+  def filter(_), do: :ok
+end
diff --git a/lib/pleroma/upload/filter/mogrifun.ex b/lib/pleroma/upload/filter/mogrifun.ex
index 7d95577a4..c8fa7b190 100644
--- a/lib/pleroma/upload/filter/mogrifun.ex
+++ b/lib/pleroma/upload/filter/mogrifun.ex
@@ -6,6 +6,10 @@ defmodule Pleroma.Upload.Filter.Mogrifun do
   @behaviour Pleroma.Upload.Filter
   alias Pleroma.Upload.Filter
 
+  @moduledoc """
+  This module is just an example of an Upload filter. It's not supposed to be used in production.
+  """
+
   @filters [
     {"implode", "1"},
     {"-raise", "20"},
@@ -34,10 +38,15 @@ defmodule Pleroma.Upload.Filter.Mogrifun do
     [{"fill", "yellow"}, {"tint", "40"}]
   ]
 
+  @spec filter(Pleroma.Upload.t()) :: :ok | {:error, String.t()}
   def filter(%Pleroma.Upload{tempfile: file, content_type: "image" <> _}) do
-    Filter.Mogrify.do_filter(file, [Enum.random(@filters)])
-
-    :ok
+    try do
+      Filter.Mogrify.do_filter(file, [Enum.random(@filters)])
+      :ok
+    rescue
+      _e in ErlangError ->
+        {:error, "mogrify command not found"}
+    end
   end
 
   def filter(_), do: :ok
diff --git a/lib/pleroma/upload/filter/mogrify.ex b/lib/pleroma/upload/filter/mogrify.ex
index 2eb758006..7a45add5a 100644
--- a/lib/pleroma/upload/filter/mogrify.ex
+++ b/lib/pleroma/upload/filter/mogrify.ex
@@ -8,11 +8,15 @@ defmodule Pleroma.Upload.Filter.Mogrify do
   @type conversion :: action :: String.t() | {action :: String.t(), opts :: String.t()}
   @type conversions :: conversion() | [conversion()]
 
+  @spec filter(Pleroma.Upload.t()) :: :ok | {:error, String.t()}
   def filter(%Pleroma.Upload{tempfile: file, content_type: "image" <> _}) do
-    filters = Pleroma.Config.get!([__MODULE__, :args])
-
-    do_filter(file, filters)
-    :ok
+    try do
+      do_filter(file, Pleroma.Config.get!([__MODULE__, :args]))
+      :ok
+    rescue
+      _e in ErlangError ->
+        {:error, "mogrify command not found"}
+    end
   end
 
   def filter(_), do: :ok