SafeZip: Add tests.

test/pleroma/safe_zip_test.exs

@@ -0,0 +1,496 @@
+defmodule Pleroma.SafeZipTest do
+  # Not making this async because it creates and deletes files
+  use ExUnit.Case
+
+  alias Pleroma.SafeZip
+
+  @fixtures_dir "test/fixtures"
+  @tmp_dir "test/zip_tmp"
+
+  setup do
+    # Ensure tmp directory exists
+    File.mkdir_p!(@tmp_dir)
+
+    on_exit(fn ->
+      # Clean up any files created during tests
+      File.rm_rf!(@tmp_dir)
+      File.mkdir_p!(@tmp_dir)
+    end)
+
+    :ok
+  end
+
+  describe "list_dir_file/1" do
+    test "lists files in a valid zip" do
+      {:ok, files} = SafeZip.list_dir_file(Path.join(@fixtures_dir, "emojis.zip"))
+      assert is_list(files)
+      assert length(files) > 0
+    end
+
+    test "returns an empty list for empty zip" do
+      {:ok, files} = SafeZip.list_dir_file(Path.join(@fixtures_dir, "empty.zip"))
+      assert files == []
+    end
+
+    test "returns error for non-existent file" do
+      assert {:error, _} = SafeZip.list_dir_file(Path.join(@fixtures_dir, "nonexistent.zip"))
+    end
+
+    test "only lists regular files, not directories" do
+      # Create a zip with both files and directories
+      zip_path = create_zip_with_directory()
+
+      # List files with SafeZip
+      {:ok, files} = SafeZip.list_dir_file(zip_path)
+
+      # Verify only regular files are listed, not directories
+      assert "file_in_dir/test_file.txt" in files
+      assert "root_file.txt" in files
+
+      # Directory entries should not be included in the list
+      refute "file_in_dir/" in files
+    end
+  end
+
+  describe "contains_all_data?/2" do
+    test "returns true when all files are in the archive" do
+      # For this test, we'll create our own zip file with known content
+      # to ensure we can test the contains_all_data? function properly
+      zip_path = create_zip_with_directory()
+      archive_data = File.read!(zip_path)
+
+      # Check if the archive contains the root file
+      # Note: The function expects charlists (Erlang strings) in the MapSet
+      assert SafeZip.contains_all_data?(archive_data, MapSet.new([~c"root_file.txt"]))
+    end
+
+    test "returns false when files are missing" do
+      archive_path = Path.join(@fixtures_dir, "emojis.zip")
+      archive_data = File.read!(archive_path)
+
+      # Create a MapSet with non-existent files
+      fset = MapSet.new([~c"nonexistent.txt"])
+
+      refute SafeZip.contains_all_data?(archive_data, fset)
+    end
+
+    test "returns false for invalid archive data" do
+      refute SafeZip.contains_all_data?("invalid data", MapSet.new([~c"file.txt"]))
+    end
+
+    test "only checks for regular files, not directories" do
+      # Create a zip with both files and directories
+      zip_path = create_zip_with_directory()
+      archive_data = File.read!(zip_path)
+
+      # Check if the archive contains a directory (should return false)
+      refute SafeZip.contains_all_data?(archive_data, MapSet.new([~c"file_in_dir/"]))
+
+      # For this test, we'll manually check if the file exists in the archive
+      # by extracting it and verifying it exists
+      extract_dir = Path.join(@tmp_dir, "extract_check")
+      File.mkdir_p!(extract_dir)
+      {:ok, files} = SafeZip.unzip_file(zip_path, extract_dir)
+
+      # Verify the root file was extracted
+      assert Enum.any?(files, fn file ->
+               Path.basename(file) == "root_file.txt"
+             end)
+
+      # Verify the file exists on disk
+      assert File.exists?(Path.join(extract_dir, "root_file.txt"))
+    end
+  end
+
+  describe "zip/4" do
+    test "creates a zip file on disk" do
+      # Create a test file
+      test_file_path = Path.join(@tmp_dir, "test_file.txt")
+      File.write!(test_file_path, "test content")
+
+      # Create a zip file
+      zip_path = Path.join(@tmp_dir, "test.zip")
+      assert {:ok, ^zip_path} = SafeZip.zip(zip_path, ["test_file.txt"], @tmp_dir, false)
+
+      # Verify the zip file exists
+      assert File.exists?(zip_path)
+    end
+
+    test "creates a zip file in memory" do
+      # Create a test file
+      test_file_path = Path.join(@tmp_dir, "test_file.txt")
+      File.write!(test_file_path, "test content")
+
+      # Create a zip file in memory
+      zip_name = Path.join(@tmp_dir, "test.zip")
+
+      assert {:ok, {^zip_name, zip_data}} =
+               SafeZip.zip(zip_name, ["test_file.txt"], @tmp_dir, true)
+
+      # Verify the zip data is binary
+      assert is_binary(zip_data)
+    end
+
+    test "returns error for unsafe paths" do
+      # Try to zip a file with path traversal
+      assert {:error, _} =
+               SafeZip.zip(
+                 Path.join(@tmp_dir, "test.zip"),
+                 ["../fixtures/test.txt"],
+                 @tmp_dir,
+                 false
+               )
+    end
+
+    test "can create zip with directories" do
+      # Create a directory structure
+      dir_path = Path.join(@tmp_dir, "test_dir")
+      File.mkdir_p!(dir_path)
+
+      file_in_dir_path = Path.join(dir_path, "file_in_dir.txt")
+      File.write!(file_in_dir_path, "file in directory")
+
+      # Create a zip file
+      zip_path = Path.join(@tmp_dir, "dir_test.zip")
+
+      assert {:ok, ^zip_path} =
+               SafeZip.zip(
+                 zip_path,
+                 ["test_dir/file_in_dir.txt"],
+                 @tmp_dir,
+                 false
+               )
+
+      # Verify the zip file exists
+      assert File.exists?(zip_path)
+
+      # Extract and verify the directory structure is preserved
+      extract_dir = Path.join(@tmp_dir, "extract")
+      {:ok, files} = SafeZip.unzip_file(zip_path, extract_dir)
+
+      # Check if the file path is in the list, accounting for possible full paths
+      assert Enum.any?(files, fn file ->
+               String.ends_with?(file, "file_in_dir.txt")
+             end)
+
+      # Verify the file exists in the expected location
+      assert File.exists?(Path.join([extract_dir, "test_dir", "file_in_dir.txt"]))
+    end
+  end
+
+  describe "unzip_file/3" do
+    test "extracts files from a zip archive" do
+      archive_path = Path.join(@fixtures_dir, "emojis.zip")
+
+      # Extract the archive
+      assert {:ok, files} = SafeZip.unzip_file(archive_path, @tmp_dir)
+
+      # Verify files were extracted
+      assert is_list(files)
+      assert length(files) > 0
+
+      # Verify at least one file exists
+      first_file = List.first(files)
+
+      # Simply check that the file exists in the tmp directory
+      assert File.exists?(Path.join(@tmp_dir, Path.basename(first_file)))
+    end
+
+    test "extracts specific files from a zip archive" do
+      archive_path = Path.join(@fixtures_dir, "emojis.zip")
+
+      # Get list of files in the archive
+      {:ok, all_files} = SafeZip.list_dir_file(archive_path)
+      file_to_extract = List.first(all_files)
+
+      # Extract only one file
+      assert {:ok, [extracted_file]} =
+               SafeZip.unzip_file(archive_path, @tmp_dir, [file_to_extract])
+
+      # Verify only the specified file was extracted
+      assert Path.basename(extracted_file) == Path.basename(file_to_extract)
+
+      # Check that the file exists in the tmp directory
+      assert File.exists?(Path.join(@tmp_dir, Path.basename(file_to_extract)))
+    end
+
+    test "returns error for invalid zip file" do
+      invalid_path = Path.join(@tmp_dir, "invalid.zip")
+      File.write!(invalid_path, "not a zip file")
+
+      assert {:error, _} = SafeZip.unzip_file(invalid_path, @tmp_dir)
+    end
+
+    test "creates directories when extracting files in subdirectories" do
+      # Create a zip with files in subdirectories
+      zip_path = create_zip_with_directory()
+
+      # Extract the archive
+      assert {:ok, files} = SafeZip.unzip_file(zip_path, @tmp_dir)
+
+      # Verify files were extracted - handle both relative and absolute paths
+      assert Enum.any?(files, fn file ->
+               Path.basename(file) == "test_file.txt" &&
+                 String.contains?(file, "file_in_dir")
+             end)
+
+      assert Enum.any?(files, fn file ->
+               Path.basename(file) == "root_file.txt"
+             end)
+
+      # Verify directory was created
+      dir_path = Path.join(@tmp_dir, "file_in_dir")
+      assert File.exists?(dir_path)
+      assert File.dir?(dir_path)
+
+      # Verify file in directory was extracted
+      file_path = Path.join(dir_path, "test_file.txt")
+      assert File.exists?(file_path)
+    end
+  end
+
+  describe "unzip_data/3" do
+    test "extracts files from zip data" do
+      archive_path = Path.join(@fixtures_dir, "emojis.zip")
+      archive_data = File.read!(archive_path)
+
+      # Extract the archive from data
+      assert {:ok, files} = SafeZip.unzip_data(archive_data, @tmp_dir)
+
+      # Verify files were extracted
+      assert is_list(files)
+      assert length(files) > 0
+
+      # Verify at least one file exists
+      first_file = List.first(files)
+
+      # Simply check that the file exists in the tmp directory
+      assert File.exists?(Path.join(@tmp_dir, Path.basename(first_file)))
+    end
+
+    test "extracts specific files from zip data" do
+      archive_path = Path.join(@fixtures_dir, "emojis.zip")
+      archive_data = File.read!(archive_path)
+
+      # Get list of files in the archive
+      {:ok, all_files} = SafeZip.list_dir_file(archive_path)
+      file_to_extract = List.first(all_files)
+
+      # Extract only one file
+      assert {:ok, extracted_files} =
+               SafeZip.unzip_data(archive_data, @tmp_dir, [file_to_extract])
+
+      # Verify only the specified file was extracted
+      assert Enum.any?(extracted_files, fn path ->
+               Path.basename(path) == Path.basename(file_to_extract)
+             end)
+
+      # Simply check that the file exists in the tmp directory
+      assert File.exists?(Path.join(@tmp_dir, Path.basename(file_to_extract)))
+    end
+
+    test "returns error for invalid zip data" do
+      assert {:error, _} = SafeZip.unzip_data("not a zip file", @tmp_dir)
+    end
+
+    test "creates directories when extracting files in subdirectories from data" do
+      # Create a zip with files in subdirectories
+      zip_path = create_zip_with_directory()
+      archive_data = File.read!(zip_path)
+
+      # Extract the archive from data
+      assert {:ok, files} = SafeZip.unzip_data(archive_data, @tmp_dir)
+
+      # Verify files were extracted - handle both relative and absolute paths
+      assert Enum.any?(files, fn file ->
+               Path.basename(file) == "test_file.txt" &&
+                 String.contains?(file, "file_in_dir")
+             end)
+
+      assert Enum.any?(files, fn file ->
+               Path.basename(file) == "root_file.txt"
+             end)
+
+      # Verify directory was created
+      dir_path = Path.join(@tmp_dir, "file_in_dir")
+      assert File.exists?(dir_path)
+      assert File.dir?(dir_path)
+
+      # Verify file in directory was extracted
+      file_path = Path.join(dir_path, "test_file.txt")
+      assert File.exists?(file_path)
+    end
+  end
+
+  # Security tests
+  describe "security checks" do
+    test "prevents path traversal in zip extraction" do
+      # Create a malicious zip file with path traversal
+      malicious_zip_path = create_malicious_zip_with_path_traversal()
+
+      # Try to extract it with SafeZip
+      assert {:error, _} = SafeZip.unzip_file(malicious_zip_path, @tmp_dir)
+
+      # Verify the file was not extracted outside the target directory
+      refute File.exists?(Path.join(Path.dirname(@tmp_dir), "traversal_attempt.txt"))
+    end
+
+    test "prevents directory traversal in zip listing" do
+      # Create a malicious zip file with path traversal
+      malicious_zip_path = create_malicious_zip_with_path_traversal()
+
+      # Try to list files with SafeZip
+      assert {:error, _} = SafeZip.list_dir_file(malicious_zip_path)
+    end
+
+    test "prevents path traversal in zip data extraction" do
+      # Create a malicious zip file with path traversal
+      malicious_zip_path = create_malicious_zip_with_path_traversal()
+      malicious_data = File.read!(malicious_zip_path)
+
+      # Try to extract it with SafeZip
+      assert {:error, _} = SafeZip.unzip_data(malicious_data, @tmp_dir)
+
+      # Verify the file was not extracted outside the target directory
+      refute File.exists?(Path.join(Path.dirname(@tmp_dir), "traversal_attempt.txt"))
+    end
+
+    test "handles zip bomb attempts" do
+      # Create a zip bomb (a zip with many files or large files)
+      zip_bomb_path = create_zip_bomb()
+
+      # The SafeZip module should handle this gracefully
+      # Either by successfully extracting it (if it's not too large)
+      # or by returning an error (if it detects a potential zip bomb)
+      result = SafeZip.unzip_file(zip_bomb_path, @tmp_dir)
+
+      case result do
+        {:ok, _} ->
+          # If it successfully extracts, make sure it didn't fill up the disk
+          # This is a simple check to ensure the extraction was controlled
+          assert File.exists?(@tmp_dir)
+
+        {:error, _} ->
+          # If it returns an error, that's also acceptable
+          # The important thing is that it doesn't crash or hang
+          assert true
+      end
+    end
+
+    test "handles deeply nested directory structures" do
+      # Create a zip with deeply nested directories
+      deep_nest_path = create_deeply_nested_zip()
+
+      # The SafeZip module should handle this gracefully
+      result = SafeZip.unzip_file(deep_nest_path, @tmp_dir)
+
+      case result do
+        {:ok, files} ->
+          # If it successfully extracts, verify the files were extracted
+          assert is_list(files)
+          assert length(files) > 0
+
+        {:error, _} ->
+          # If it returns an error, that's also acceptable
+          # The important thing is that it doesn't crash or hang
+          assert true
+      end
+    end
+  end
+
+  # Helper functions to create test fixtures
+
+  # Creates a zip file with a path traversal attempt
+  defp create_malicious_zip_with_path_traversal do
+    malicious_zip_path = Path.join(@tmp_dir, "path_traversal.zip")
+
+    # Create a file to include in the zip
+    test_file_path = Path.join(@tmp_dir, "test_file.txt")
+    File.write!(test_file_path, "malicious content")
+
+    # Use Erlang's zip module directly to create a zip with path traversal
+    {:ok, charlist_path} =
+      :zip.create(
+        String.to_charlist(malicious_zip_path),
+        [{String.to_charlist("../traversal_attempt.txt"), File.read!(test_file_path)}]
+      )
+
+    to_string(charlist_path)
+  end
+
+  # Creates a zip file with directory entries
+  defp create_zip_with_directory do
+    zip_path = Path.join(@tmp_dir, "with_directory.zip")
+
+    # Create files to include in the zip
+    root_file_path = Path.join(@tmp_dir, "root_file.txt")
+    File.write!(root_file_path, "root file content")
+
+    # Create a directory and a file in it
+    dir_path = Path.join(@tmp_dir, "file_in_dir")
+    File.mkdir_p!(dir_path)
+
+    file_in_dir_path = Path.join(dir_path, "test_file.txt")
+    File.write!(file_in_dir_path, "file in directory content")
+
+    # Use Erlang's zip module to create a zip with directory structure
+    {:ok, charlist_path} =
+      :zip.create(
+        String.to_charlist(zip_path),
+        [
+          {String.to_charlist("root_file.txt"), File.read!(root_file_path)},
+          {String.to_charlist("file_in_dir/test_file.txt"), File.read!(file_in_dir_path)}
+        ]
+      )
+
+    to_string(charlist_path)
+  end
+
+  # Creates a zip bomb (a zip with many small files)
+  defp create_zip_bomb do
+    zip_path = Path.join(@tmp_dir, "zip_bomb.zip")
+
+    # Create a small file to duplicate many times
+    small_file_path = Path.join(@tmp_dir, "small_file.txt")
+    File.write!(small_file_path, String.duplicate("A", 100))
+
+    # Create a list of many files to include in the zip
+    file_entries =
+      for i <- 1..100 do
+        {String.to_charlist("file_#{i}.txt"), File.read!(small_file_path)}
+      end
+
+    # Use Erlang's zip module to create a zip with many files
+    {:ok, charlist_path} =
+      :zip.create(
+        String.to_charlist(zip_path),
+        file_entries
+      )
+
+    to_string(charlist_path)
+  end
+
+  # Creates a zip with deeply nested directories
+  defp create_deeply_nested_zip do
+    zip_path = Path.join(@tmp_dir, "deep_nest.zip")
+
+    # Create a file to include in the zip
+    file_content = "test content"
+
+    # Create a list of deeply nested files
+    file_entries =
+      for i <- 1..10 do
+        nested_path = Enum.reduce(1..i, "nested", fn j, acc -> "#{acc}/level_#{j}" end)
+        {String.to_charlist("#{nested_path}/file.txt"), file_content}
+      end
+
+    # Use Erlang's zip module to create a zip with deeply nested directories
+    {:ok, charlist_path} =
+      :zip.create(
+        String.to_charlist(zip_path),
+        file_entries
+      )
+
+    to_string(charlist_path)
+  end
+end