Merge branch '24570-use-re2-for-user-supplied-regexp-9-3' into 'security-9-3'

24570 use re2 for user supplied regexp 9 3

See merge request !2129

4 files changed, 108 insertions, 0 deletions

diff --git a/spec/lib/gitlab/ci/trace/stream_spec.rb b/spec/lib/gitlab/ci/trace/stream_spec.rb
index bbb3f9912a3..13f0338b6aa 100644
--- a/spec/lib/gitlab/ci/trace/stream_spec.rb
+++ b/spec/lib/gitlab/ci/trace/stream_spec.rb
@@ -293,5 +293,12 @@ describe Gitlab::Ci::Trace::Stream do
 
       it { is_expected.to eq("65") }
     end
+
+    context 'malicious regexp' do
+      let(:data) { malicious_text }  
+      let(:regex) { malicious_regexp }
+
+      include_examples 'malicious regexp'
+    end
   end
 end
diff --git a/spec/lib/gitlab/route_map_spec.rb b/spec/lib/gitlab/route_map_spec.rb
index 21c00c6e5b8..e8feb21e4d7 100644
--- a/spec/lib/gitlab/route_map_spec.rb
+++ b/spec/lib/gitlab/route_map_spec.rb
@@ -55,6 +55,19 @@ describe Gitlab::RouteMap, lib: true do
   end
 
   describe '#public_path_for_source_path' do
+    context 'malicious regexp' do
+      include_examples 'malicious regexp'
+
+      subject do
+        map = described_class.new(<<-"MAP".strip_heredoc)
+        - source: '#{malicious_regexp}'
+          public: '/'
+        MAP
+
+        map.public_path_for_source_path(malicious_text)
+      end
+    end
+
     subject do
       described_class.new(<<-'MAP'.strip_heredoc)
         # Team data
diff --git a/spec/lib/gitlab/untrusted_regexp_spec.rb b/spec/lib/gitlab/untrusted_regexp_spec.rb
new file mode 100644
index 00000000000..66045917cb3
--- /dev/null
+++ b/spec/lib/gitlab/untrusted_regexp_spec.rb
@@ -0,0 +1,80 @@
+require 'spec_helper'
+
+describe Gitlab::UntrustedRegexp do
+  describe '#initialize' do
+    subject { described_class.new(pattern) }
+
+    context 'invalid regexp' do
+      let(:pattern) { '[' }
+
+      it { expect { subject }.to raise_error(RegexpError) }
+    end
+  end
+
+  describe '#replace_all' do
+    it 'replaces all instances of the match in a string' do
+      result = described_class.new('foo').replace_all('foo bar foo', 'oof')
+
+      expect(result).to eq('oof bar oof')
+    end
+  end
+
+  describe '#replace' do
+    it 'replaces the first instance of the match in a string' do
+      result = described_class.new('foo').replace('foo bar foo', 'oof')
+
+      expect(result).to eq('oof bar foo')
+    end
+  end
+
+  describe '#===' do
+    it 'returns true for a match' do
+      result = described_class.new('foo') === 'a foo here'
+
+      expect(result).to be_truthy
+    end
+
+    it 'returns false for no match' do
+      result = described_class.new('foo') === 'a bar here'
+
+      expect(result).to be_falsy
+    end
+  end
+
+  describe '#scan' do
+    subject { described_class.new(regexp).scan(text) }
+    context 'malicious regexp' do
+      let(:text) { malicious_text }
+      let(:regexp) { malicious_regexp }
+ 
+      include_examples 'malicious regexp'
+    end
+
+    context 'no capture group' do
+      let(:regexp) { '.+' }
+      let(:text) { 'foo' }
+
+      it 'returns the whole match' do
+        is_expected.to eq(['foo'])
+      end
+    end
+
+    context 'one capture group' do
+      let(:regexp) { '(f).+' }
+      let(:text) { 'foo' }
+
+      it 'returns the captured part' do
+        is_expected.to eq([%w[f]])
+      end
+    end
+
+    context 'two capture groups' do
+      let(:regexp) { '(f).(o)' }
+      let(:text) { 'foo' }
+
+      it 'returns the captured parts' do
+        is_expected.to eq([%w[f o]])
+      end
+    end
+  end
+end
diff --git a/spec/support/malicious_regexp_shared_examples.rb b/spec/support/malicious_regexp_shared_examples.rb
new file mode 100644
index 00000000000..ac5d22298bb
--- /dev/null
+++ b/spec/support/malicious_regexp_shared_examples.rb
@@ -0,0 +1,8 @@
+shared_examples 'malicious regexp' do
+  let(:malicious_text)  { 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa!' }
+  let(:malicious_regexp) { '(?i)^(([a-z])+.)+[A-Z]([a-z])+$' }
+
+  it 'takes under a second' do
+    expect { Timeout.timeout(1) { subject } }.not_to raise_error
+  end
+end