Files
bDS2/test/bds/csm026_toctou_file_system_test.exs

107 lines
3.4 KiB
Elixir

defmodule BDS.TOCTOU.FileSystemTest do
use ExUnit.Case, async: true
alias BDS.Rendering.FileSystem, as: TemplateFileSystem
describe "try_read/2 eliminates TOCTOU race" do
@tag :tmp_dir
test "reads file atomically without separate existence check", %{tmp_dir: tmp_dir} do
File.write!(Path.join(tmp_dir, "header.liquid"), "HEADER CONTENT")
fs = TemplateFileSystem.new(tmp_dir)
assert {:ok, "HEADER CONTENT"} = TemplateFileSystem.try_read(fs, "header")
end
@tag :tmp_dir
test "returns {:error, :enoent} for missing templates", %{tmp_dir: tmp_dir} do
fs = TemplateFileSystem.new(tmp_dir)
assert {:error, :enoent} = TemplateFileSystem.try_read(fs, "nonexistent")
end
@tag :tmp_dir
test "falls through to next root path when first is missing", %{tmp_dir: tmp_dir} do
root_a = Path.join(tmp_dir, "a")
root_b = Path.join(tmp_dir, "b")
File.mkdir_p!(root_a)
File.mkdir_p!(root_b)
File.write!(Path.join(root_b, "partial.liquid"), "FROM B")
fs = TemplateFileSystem.new([root_a, root_b])
assert {:ok, "FROM B"} = TemplateFileSystem.try_read(fs, "partial")
end
@tag :tmp_dir
test "first root path wins when both have the template", %{tmp_dir: tmp_dir} do
root_a = Path.join(tmp_dir, "a")
root_b = Path.join(tmp_dir, "b")
File.mkdir_p!(root_a)
File.mkdir_p!(root_b)
File.write!(Path.join(root_a, "shared.liquid"), "FROM A")
File.write!(Path.join(root_b, "shared.liquid"), "FROM B")
fs = TemplateFileSystem.new([root_a, root_b])
assert {:ok, "FROM A"} = TemplateFileSystem.try_read(fs, "shared")
end
@tag :tmp_dir
test "file deleted between candidate_paths and try_read does not crash", %{tmp_dir: tmp_dir} do
path = Path.join(tmp_dir, "ephemeral.liquid")
File.write!(path, "TEMPORARY")
fs = TemplateFileSystem.new(tmp_dir)
_candidates = TemplateFileSystem.candidate_paths(fs, "ephemeral")
File.rm!(path)
assert {:error, :enoent} = TemplateFileSystem.try_read(fs, "ephemeral")
end
end
describe "read_template_file/2 protocol uses atomic read" do
@tag :tmp_dir
test "reads existing template", %{tmp_dir: tmp_dir} do
File.write!(Path.join(tmp_dir, "footer.liquid"), "FOOTER")
fs = TemplateFileSystem.new(tmp_dir)
assert "FOOTER" = Liquex.FileSystem.read_template_file(fs, "footer")
end
@tag :tmp_dir
test "raises on missing template", %{tmp_dir: tmp_dir} do
fs = TemplateFileSystem.new(tmp_dir)
assert_raise Liquex.Error, ~r/No such template/, fn ->
Liquex.FileSystem.read_template_file(fs, "missing")
end
end
end
describe "candidate_paths/2 validation" do
test "raises on empty path" do
fs = TemplateFileSystem.new("/tmp")
assert_raise Liquex.Error, ~r/Illegal template path/, fn ->
TemplateFileSystem.candidate_paths(fs, "")
end
end
test "raises on absolute path" do
fs = TemplateFileSystem.new("/tmp")
assert_raise Liquex.Error, ~r/Illegal template path/, fn ->
TemplateFileSystem.candidate_paths(fs, "/etc/passwd")
end
end
test "raises on path traversal" do
fs = TemplateFileSystem.new("/tmp")
assert_raise Liquex.Error, ~r/Illegal template path/, fn ->
TemplateFileSystem.candidate_paths(fs, "../secret")
end
end
end
end