1 files changed, 52 insertions, 0 deletions
diff --git a/spec/lib/gitlab/email/hook/validate_addresses_interceptor_spec.rb b/spec/lib/gitlab/email/hook/validate_addresses_interceptor_spec.rb
new file mode 100644
index 00000000000..a3f0158db40
--- /dev/null
+++ b/spec/lib/gitlab/email/hook/validate_addresses_interceptor_spec.rb
@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Email::Hook::ValidateAddressesInterceptor do
+  describe 'UNSAFE_CHARACTERS' do
+    subject { described_class::UNSAFE_CHARACTERS }
+
+    it { is_expected.to match('\\') }
+    it { is_expected.to match("\x00") }
+    it { is_expected.to match("\x01") }
+    it { is_expected.not_to match('') }
+    it { is_expected.not_to match('user@example.com') }
+    it { is_expected.not_to match('foo-123+bar_456@example.com') }
+  end
+
+  describe '.delivering_email' do
+    let(:mail) do
+      ActionMailer::Base.mail(to: 'test@mail.com', from: 'info@mail.com', subject: 'title', body: 'hello')
+    end
+
+    let(:unsafe_email) { "evil+\x01$HOME@example.com" }
+
+    it 'sends emails to normal addresses' do
+      expect(Gitlab::AuthLogger).not_to receive(:info)
+      expect { mail.deliver_now }.to change(ActionMailer::Base.deliveries, :count)
+    end
+
+    [:from, :to, :cc, :bcc].each do |header|
+      it "does not send emails if the #{header.inspect} header contains unsafe characters" do
+        mail[header] = unsafe_email
+
+        expect(Gitlab::AuthLogger).to receive(:info).with(
+          message: 'Skipping email with unsafe characters in address',
+          address: unsafe_email,
+          subject: mail.subject
+        )
+
+        expect { mail.deliver_now }.not_to change(ActionMailer::Base.deliveries, :count)
+      end
+    end
+
+    [:reply_to].each do |header|
+      it "sends emails if the #{header.inspect} header contains unsafe characters" do
+        mail[header] = unsafe_email
+
+        expect(Gitlab::AuthLogger).not_to receive(:info)
+        expect { mail.deliver_now }.to change(ActionMailer::Base.deliveries, :count)
+      end
+    end
+  end
+end