Emoji, Pack, Backup, Frontend: Use SafeZip

lib/mix/tasks/pleroma/emoji.ex

@@ -93,6 +93,7 @@ defmodule Mix.Tasks.Pleroma.Emoji do
         )
 
         files = fetch_and_decode!(files_loc)
+        files_to_unzip = for({_, f} <- files, do: f)
 
         IO.puts(IO.ANSI.format(["Unpacking ", :bright, pack_name]))
 
@@ -103,17 +104,7 @@ defmodule Mix.Tasks.Pleroma.Emoji do
             pack_name
           ])
 
-        files_to_unzip =
-          Enum.map(
-            files,
-            fn {_, f} -> to_charlist(f) end
-          )
-
-        {:ok, _} =
-          :zip.unzip(binary_archive,
-            cwd: String.to_charlist(pack_path),
-            file_list: files_to_unzip
-          )
+        {:ok, _} = Pleroma.SafeZip.unzip_data(binary_archive, pack_path, files_to_unzip)
 
         IO.puts(IO.ANSI.format(["Writing pack.json for ", :bright, pack_name]))
 
@@ -201,7 +192,7 @@ defmodule Mix.Tasks.Pleroma.Emoji do
 
     tmp_pack_dir = Path.join(System.tmp_dir!(), "emoji-pack-#{name}")
 
-    {:ok, _} = :zip.unzip(binary_archive, cwd: String.to_charlist(tmp_pack_dir))
+    {:ok, _} = Pleroma.SafeZip.unzip_data(binary_archive, tmp_pack_dir)
 
     emoji_map = Pleroma.Emoji.Loader.make_shortcode_to_file_map(tmp_pack_dir, exts)
 

lib/pleroma/emoji/pack.ex

@@ -25,11 +25,12 @@ defmodule Pleroma.Emoji.Pack do
   alias Pleroma.Emoji
   alias Pleroma.Emoji.Pack
   alias Pleroma.Utils
+  alias Pleroma.SafeZip
 
   @spec create(String.t()) :: {:ok, t()} | {:error, File.posix()} | {:error, :empty_values}
   def create(name) do
     with :ok <- validate_not_empty([name]),
-         dir <- Path.join(emoji_path(), name),
+         dir <- path_join_name_safe(emoji_path(), name),
          :ok <- File.mkdir(dir) do
       save_pack(%__MODULE__{pack_file: Path.join(dir, "pack.json")})
     end
@@ -65,43 +66,21 @@ defmodule Pleroma.Emoji.Pack do
           {:ok, [binary()]} | {:error, File.posix(), binary()} | {:error, :empty_values}
   def delete(name) do
     with :ok <- validate_not_empty([name]),
-         pack_path <- Path.join(emoji_path(), name) do
+         pack_path <- path_join_name_safe(emoji_path(), name) do
       File.rm_rf(pack_path)
     end
   end
 
-  @spec unpack_zip_emojies(list(tuple())) :: list(map())
-  defp unpack_zip_emojies(zip_files) do
-    Enum.reduce(zip_files, [], fn
-      {_, path, s, _, _, _}, acc when elem(s, 2) == :regular ->
-        with(
-          filename <- Path.basename(path),
-          shortcode <- Path.basename(filename, Path.extname(filename)),
-          false <- Emoji.exist?(shortcode)
-        ) do
-          [%{path: path, filename: path, shortcode: shortcode} | acc]
-        else
-          _ -> acc
-        end
-
-      _, acc ->
-        acc
-    end)
-  end
-
   @spec add_file(t(), String.t(), Path.t(), Plug.Upload.t()) ::
           {:ok, t()}
           | {:error, File.posix() | atom()}
   def add_file(%Pack{} = pack, _, _, %Plug.Upload{content_type: "application/zip"} = file) do
-    with {:ok, zip_files} <- :zip.table(to_charlist(file.path)),
-         [_ | _] = emojies <- unpack_zip_emojies(zip_files),
+    with {:ok, zip_files} <- SafeZip.list_dir_file(file.path),
+         [_ | _] = emojies <- map_zip_emojies(zip_files),
          {:ok, tmp_dir} <- Utils.tmp_dir("emoji") do
       try do
         {:ok, _emoji_files} =
-          :zip.unzip(
-            to_charlist(file.path),
-            [{:file_list, Enum.map(emojies, & &1[:path])}, {:cwd, String.to_charlist(tmp_dir)}]
-          )
+          SafeZip.unzip_file(file.path, tmp_dir, Enum.map(emojies, & &1[:path]))
 
         {_, updated_pack} =
           Enum.map_reduce(emojies, pack, fn item, emoji_pack ->
@@ -292,7 +271,7 @@ defmodule Pleroma.Emoji.Pack do
   @spec load_pack(String.t()) :: {:ok, t()} | {:error, :file.posix()}
   def load_pack(name) do
     name = Path.basename(name)
-    pack_file = Path.join([emoji_path(), name, "pack.json"])
+    pack_file = path_join_name_safe(emoji_path(), name) |> Path.join("pack.json")
 
     with {:ok, _} <- File.stat(pack_file),
          {:ok, pack_data} <- File.read(pack_file) do
@@ -416,10 +395,9 @@ defmodule Pleroma.Emoji.Pack do
   end
 
   defp create_archive_and_cache(pack, hash) do
-    files = [~c"pack.json" | Enum.map(pack.files, fn {_, file} -> to_charlist(file) end)]
-
-    {:ok, {_, result}} =
-      :zip.zip(~c"#{pack.name}.zip", files, [:memory, cwd: to_charlist(pack.path)])
+    pack_file_list = Enum.into(pack.files, [], fn {_, f} -> f end)
+    files = ["pack.json" | pack_file_list]
+    {:ok, {_, result}} = SafeZip.zip("#{pack.name}.zip", files, pack.path, true)
 
     ttl_per_file = Pleroma.Config.get!([:emoji, :shared_pack_cache_seconds_per_file])
     overall_ttl = :timer.seconds(ttl_per_file * Enum.count(files))
@@ -478,7 +456,7 @@ defmodule Pleroma.Emoji.Pack do
   end
 
   defp save_file(%Plug.Upload{path: upload_path}, pack, filename) do
-    file_path = Path.join(pack.path, filename)
+    file_path = path_join_safe(pack.path, filename)
     create_subdirs(file_path)
 
     with {:ok, _} <- File.copy(upload_path, file_path) do
@@ -497,8 +475,8 @@ defmodule Pleroma.Emoji.Pack do
   end
 
   defp rename_file(pack, filename, new_filename) do
-    old_path = Path.join(pack.path, filename)
-    new_path = Path.join(pack.path, new_filename)
+    old_path = path_join_safe(pack.path, filename)
+    new_path = path_join_safe(pack.path, new_filename)
     create_subdirs(new_path)
 
     with :ok <- File.rename(old_path, new_path) do
@@ -516,7 +494,7 @@ defmodule Pleroma.Emoji.Pack do
 
   defp remove_file(pack, shortcode) do
     with {:ok, filename} <- get_filename(pack, shortcode),
-         emoji <- Path.join(pack.path, filename),
+         emoji <- path_join_safe(pack.path, filename),
          :ok <- File.rm(emoji) do
       remove_dir_if_empty(emoji, filename)
     end
@@ -534,7 +512,7 @@ defmodule Pleroma.Emoji.Pack do
 
   defp get_filename(pack, shortcode) do
     with %{^shortcode => filename} when is_binary(filename) <- pack.files,
-         file_path <- Path.join(pack.path, filename),
+         file_path <- path_join_safe(pack.path, filename),
          {:ok, _} <- File.stat(file_path) do
       {:ok, filename}
     else
@@ -584,11 +562,10 @@ defmodule Pleroma.Emoji.Pack do
 
   defp unzip(archive, pack_info, remote_pack, local_pack) do
     with :ok <- File.mkdir_p!(local_pack.path) do
-      files = Enum.map(remote_pack["files"], fn {_, path} -> to_charlist(path) end)
+      files = Enum.map(remote_pack["files"], fn {_, path} -> path end)
       # Fallback cannot contain a pack.json file
-      files = if pack_info[:fallback], do: files, else: [~c"pack.json" | files]
-
-      :zip.unzip(archive, cwd: to_charlist(local_pack.path), file_list: files)
+      files = if pack_info[:fallback], do: files, else: ["pack.json" | files]
+      SafeZip.unzip_data(archive, local_pack.path, files)
     end
   end
 
@@ -649,13 +626,43 @@ defmodule Pleroma.Emoji.Pack do
   end
 
   defp validate_has_all_files(pack, zip) do
-    with {:ok, f_list} <- :zip.unzip(zip, [:memory]) do
-      # Check if all files from the pack.json are in the archive
-      pack.files
-      |> Enum.all?(fn {_, from_manifest} ->
-        List.keyfind(f_list, to_charlist(from_manifest), 0)
+    # Check if all files from the pack.json are in the archive
+    eset =
+      Enum.reduce(pack.files, MapSet.new(), fn
+        {_, file}, s -> MapSet.put(s, to_charlist(file))
       end)
-      |> if(do: :ok, else: {:error, :incomplete})
+
+    if SafeZip.contains_all_data?(zip, eset),
+      do: :ok,
+      else: {:error, :incomplete}
+  end
+
+  defp path_join_name_safe(dir, name) do
+    if to_string(name) != Path.basename(name) or name in ["..", ".", ""] do
+      raise "Invalid or malicious pack name: #{name}"
+    else
+      Path.join(dir, name)
     end
   end
+
+  defp path_join_safe(dir, path) do
+    {:ok, safe_path} = Path.safe_relative(path)
+    Path.join(dir, safe_path)
+  end
+
+  defp map_zip_emojies(zip_files) do
+    Enum.reduce(zip_files, [], fn path, acc ->
+      with(
+        filename <- Path.basename(path),
+        shortcode <- Path.basename(filename, Path.extname(filename)),
+        # note: this only checks the shortcode, if an emoji already exists on the same path, but
+        #       with a different shortcode, the existing one will be degraded to an alias of the new
+        false <- Emoji.exist?(shortcode)
+      ) do
+        [%{path: path, filename: path, shortcode: shortcode} | acc]
+      else
+        _ -> acc
+      end
+    end)
+  end
 end

lib/pleroma/frontend.ex

@@ -65,24 +65,12 @@ defmodule Pleroma.Frontend do
   end
 
   def unzip(zip, dest) do
-    with {:ok, unzipped} <- :zip.unzip(zip, [:memory]) do
-      File.rm_rf!(dest)
-      File.mkdir_p!(dest)
+    File.rm_rf!(dest)
+    File.mkdir_p!(dest)
 
-      Enum.each(unzipped, fn {filename, data} ->
-        path = filename
-
-        new_file_path = Path.join(dest, path)
-
-        path
-        |> Path.dirname()
-        |> then(&Path.join(dest, &1))
-        |> File.mkdir_p!()
-
-        if not File.dir?(new_file_path) do
-          File.write!(new_file_path, data)
-        end
-      end)
+    case Pleroma.SafeZip.unzip_data(zip, dest) do
+      {:ok, _} -> :ok
+      error -> error
     end
   end
 

lib/pleroma/user/backup.ex

@@ -22,6 +22,8 @@ defmodule Pleroma.User.Backup do
   alias Pleroma.Web.ActivityPub.Transmogrifier
   alias Pleroma.Web.ActivityPub.UserView
   alias Pleroma.Workers.BackupWorker
+  alias Pleroma.SafeZip
+  alias Pleroma.Upload
 
   @type t :: %__MODULE__{}
 
@@ -179,12 +181,12 @@ defmodule Pleroma.User.Backup do
   end
 
   @files [
-    ~c"actor.json",
-    ~c"outbox.json",
-    ~c"likes.json",
-    ~c"bookmarks.json",
-    ~c"followers.json",
-    ~c"following.json"
+    "actor.json",
+    "outbox.json",
+    "likes.json",
+    "bookmarks.json",
+    "followers.json",
+    "following.json"
   ]
 
   @spec run(t()) :: {:ok, t()} | {:error, :failed}
@@ -200,7 +202,7 @@ defmodule Pleroma.User.Backup do
          {_, :ok} <- {:followers, followers(backup.tempdir, backup.user)},
          {_, :ok} <- {:following, following(backup.tempdir, backup.user)},
          {_, {:ok, _zip_path}} <-
-           {:zip, :zip.create(to_charlist(tempfile), @files, cwd: to_charlist(backup.tempdir))},
+           {:zip, SafeZip.zip(tempfile, @files, backup.tempdir)},
          {_, {:ok, %File.Stat{size: zip_size}}} <- {:filestat, File.stat(tempfile)},
          {:ok, updated_backup} <- update_record(backup, %{file_size: zip_size}) do
       {:ok, updated_backup}