diff options
author | Kamil TrzciĆski <ayufan@ayufan.eu> | 2019-01-02 22:01:11 +0300 |
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committer | Yorick Peterse <yorickpeterse@gmail.com> | 2019-01-31 18:52:48 +0300 |
commit | 66744469d4f2c444c0248b84096d252db749d01c (patch) | |
tree | 0b71d2c71a195d61dca9b814e7fff31abe59004e /spec/lib/safe_zip | |
parent | a1bf088201702ec4d36015c8f4cb635fa2ee2c5b (diff) |
Extract GitLab Pages using RubyZip
RubyZip allows us to perform strong validation of
expanded paths where we do extract file.
We introduce the following additional checks
to extract routines:
1. None of path components can be symlinked,
2. We drop privileges support for directories,
3. Symlink source needs to point within the target directory,
like `public/`,
4. The symlink source needs to exist ahead of time.
Diffstat (limited to 'spec/lib/safe_zip')
-rw-r--r-- | spec/lib/safe_zip/entry_spec.rb | 196 | ||||
-rw-r--r-- | spec/lib/safe_zip/extract_params_spec.rb | 54 | ||||
-rw-r--r-- | spec/lib/safe_zip/extract_spec.rb | 80 |
3 files changed, 330 insertions, 0 deletions
diff --git a/spec/lib/safe_zip/entry_spec.rb b/spec/lib/safe_zip/entry_spec.rb new file mode 100644 index 00000000000..115e28c5994 --- /dev/null +++ b/spec/lib/safe_zip/entry_spec.rb @@ -0,0 +1,196 @@ +require 'spec_helper' + +describe SafeZip::Entry do + let(:target_path) { Dir.mktmpdir('safe-zip') } + let(:directories) { %w(public folder/with/subfolder) } + let(:params) { SafeZip::ExtractParams.new(directories: directories, to: target_path) } + + let(:entry) { described_class.new(zip_archive, zip_entry, params) } + let(:entry_name) { 'public/folder/index.html' } + let(:entry_path_dir) { File.join(target_path, File.dirname(entry_name)) } + let(:entry_path) { File.join(target_path, entry_name) } + let(:zip_archive) { double } + + let(:zip_entry) do + double( + name: entry_name, + file?: false, + directory?: false, + symlink?: false) + end + + after do + FileUtils.remove_entry_secure(target_path) + end + + context '#path_dir' do + subject { entry.path_dir } + + it { is_expected.to eq(target_path + '/public/folder') } + end + + context '#exist?' do + subject { entry.exist? } + + context 'when entry does not exist' do + it { is_expected.not_to be_truthy } + end + + context 'when entry does exist' do + before do + create_entry + end + + it { is_expected.to be_truthy } + end + end + + describe '#extract' do + subject { entry.extract } + + context 'when entry does not match the filtered directories' do + using RSpec::Parameterized::TableSyntax + + where(:entry_name) do + [ + 'assets/folder/index.html', + 'public/../folder/index.html', + 'public/../../../../../index.html', + '../../../../../public/index.html', + '/etc/passwd' + ] + end + + with_them do + it 'does not extract file' do + is_expected.to be_falsey + end + end + end + + context 'when entry does exist' do + before do + create_entry + end + + it 'raises an exception' do + expect { subject }.to raise_error(SafeZip::Extract::AlreadyExistsError) + end + end + + context 'when entry type is unknown' do + it 'raises an exception' do + expect { subject }.to raise_error(SafeZip::Extract::UnsupportedEntryError) + end + end + + context 'when entry is valid' do + shared_examples 'secured symlinks' do + context 'when we try to extract entry into symlinked folder' do + before do + FileUtils.mkdir_p(File.join(target_path, "source")) + File.symlink("source", File.join(target_path, "public")) + end + + it 'raises an exception' do + expect { subject }.to raise_error(SafeZip::Extract::PermissionDeniedError) + end + end + end + + context 'and is file' do + before do + allow(zip_entry).to receive(:file?) { true } + end + + it 'does extract file' do + expect(zip_archive).to receive(:extract) + .with(zip_entry, entry_path) + .and_return(true) + + is_expected.to be_truthy + end + + it_behaves_like 'secured symlinks' + end + + context 'and is directory' do + let(:entry_name) { 'public/folder/assets' } + + before do + allow(zip_entry).to receive(:directory?) { true } + end + + it 'does create directory' do + is_expected.to be_truthy + + expect(File.exist?(entry_path)).to eq(true) + end + + it_behaves_like 'secured symlinks' + end + + context 'and is symlink' do + let(:entry_name) { 'public/folder/assets' } + + before do + allow(zip_entry).to receive(:symlink?) { true } + allow(zip_archive).to receive(:read).with(zip_entry) { entry_symlink } + end + + shared_examples 'a valid symlink' do + it 'does create symlink' do + is_expected.to be_truthy + + expect(File.exist?(entry_path)).to eq(true) + end + end + + context 'when source is within target' do + let(:entry_symlink) { '../images' } + + context 'but does not exist' do + it 'raises an exception' do + expect { subject }.to raise_error(SafeZip::Extract::SymlinkSourceDoesNotExistError) + end + end + + context 'and does exist' do + before do + FileUtils.mkdir_p(File.join(target_path, 'public', 'images')) + end + + it_behaves_like 'a valid symlink' + end + end + + context 'when source points outside of target' do + let(:entry_symlink) { '../../images' } + + before do + FileUtils.mkdir(File.join(target_path, 'images')) + end + + it 'raises an exception' do + expect { subject }.to raise_error(SafeZip::Extract::PermissionDeniedError) + end + end + + context 'when source points to /etc/passwd' do + let(:entry_symlink) { '/etc/passwd' } + + it 'raises an exception' do + expect { subject }.to raise_error(SafeZip::Extract::PermissionDeniedError) + end + end + end + end + end + + private + + def create_entry + FileUtils.mkdir_p(entry_path_dir) + FileUtils.touch(entry_path) + end +end diff --git a/spec/lib/safe_zip/extract_params_spec.rb b/spec/lib/safe_zip/extract_params_spec.rb new file mode 100644 index 00000000000..85e22cfa495 --- /dev/null +++ b/spec/lib/safe_zip/extract_params_spec.rb @@ -0,0 +1,54 @@ +require 'spec_helper' + +describe SafeZip::ExtractParams do + let(:target_path) { Dir.mktmpdir("safe-zip") } + let(:params) { described_class.new(directories: directories, to: target_path) } + let(:directories) { %w(public folder/with/subfolder) } + + after do + FileUtils.remove_entry_secure(target_path) + end + + describe '#extract_path' do + subject { params.extract_path } + + it { is_expected.to eq(target_path) } + end + + describe '#matching_target_directory' do + using RSpec::Parameterized::TableSyntax + + subject { params.matching_target_directory(target_path + path) } + + where(:path, :result) do + '/public/index.html' | '/public/' + '/non/existing/path' | nil + '/public' | nil + '/folder/with/index.html' | nil + end + + with_them do + it { is_expected.to eq(result ? target_path + result : nil) } + end + end + + describe '#target_directories' do + subject { params.target_directories } + + it 'starts with target_path' do + is_expected.to all(start_with(target_path + '/')) + end + + it 'ends with / for all paths' do + is_expected.to all(end_with('/')) + end + end + + describe '#directories_wildcard' do + subject { params.directories_wildcard } + + it 'adds * for all paths' do + is_expected.to all(end_with('/*')) + end + end +end diff --git a/spec/lib/safe_zip/extract_spec.rb b/spec/lib/safe_zip/extract_spec.rb new file mode 100644 index 00000000000..dc7e25c0cf6 --- /dev/null +++ b/spec/lib/safe_zip/extract_spec.rb @@ -0,0 +1,80 @@ +require 'spec_helper' + +describe SafeZip::Extract do + let(:target_path) { Dir.mktmpdir('safe-zip') } + let(:directories) { %w(public) } + let(:object) { described_class.new(archive) } + let(:archive) { Rails.root.join('spec', 'fixtures', 'safe_zip', archive_name) } + + after do + FileUtils.remove_entry_secure(target_path) + end + + context '#extract' do + subject { object.extract(directories: directories, to: target_path) } + + shared_examples 'extracts archive' do |param| + before do + stub_feature_flags(safezip_use_rubyzip: param) + end + + it 'does extract archive' do + subject + + expect(File.exist?(File.join(target_path, 'public', 'index.html'))).to eq(true) + expect(File.exist?(File.join(target_path, 'source'))).to eq(false) + end + end + + shared_examples 'fails to extract archive' do |param| + before do + stub_feature_flags(safezip_use_rubyzip: param) + end + + it 'does not extract archive' do + expect { subject }.to raise_error(SafeZip::Extract::Error) + end + end + + %w(valid-simple.zip valid-symlinks-first.zip valid-non-writeable.zip).each do |name| + context "when using #{name} archive" do + let(:archive_name) { name } + + context 'for RubyZip' do + it_behaves_like 'extracts archive', true + end + + context 'for UnZip' do + it_behaves_like 'extracts archive', false + end + end + end + + %w(invalid-symlink-does-not-exist.zip invalid-symlinks-outside.zip).each do |name| + context "when using #{name} archive" do + let(:archive_name) { name } + + context 'for RubyZip' do + it_behaves_like 'fails to extract archive', true + end + + context 'for UnZip (UNSAFE)' do + it_behaves_like 'extracts archive', false + end + end + end + + context 'when no matching directories are found' do + let(:archive_name) { 'valid-simple.zip' } + let(:directories) { %w(non/existing) } + + context 'for RubyZip' do + it_behaves_like 'fails to extract archive', true + end + + context 'for UnZip' do + it_behaves_like 'fails to extract archive', false + end + end + end +end |