Disable MD5 usage in rubygems package when in fips mode

app/services/packages/rubygems/create_gemspec_service.rb

@@ -24,12 +24,14 @@ def write_gemspec_to_file
           file.write(content)
           file.flush
+          md5 = Gitlab::FIPS.enabled? ? nil : Digest::MD5.hexdigest(content)
+
           package.package_files.create!(
             file: file,
             size: file.size,
             file_name: "#{gemspec.name}.gemspec",
             file_sha1: Digest::SHA1.hexdigest(content),
-            file_md5: Digest::MD5.hexdigest(content),
+            file_md5: md5,
             file_sha256: Digest::SHA256.hexdigest(content)
           )
         ensure

spec/services/packages/rubygems/create_gemspec_service_spec.rb

@@ -24,5 +24,18 @@
       expect(gemspec_file.file_sha1).not_to be_nil
       expect(gemspec_file.file_sha256).not_to be_nil
     end
+
+    context 'with FIPS mode', :fips_mode do
+      it 'does not generate file_md5' do
+        expect { subject }.to change { package.package_files.count }.by(1)
+
+        gemspec_file = package.package_files.find_by(file_name: "#{gemspec.name}.gemspec")
+        expect(gemspec_file.file).not_to be_nil
+        expect(gemspec_file.size).not_to be_nil
+        expect(gemspec_file.file_md5).to be_nil
+        expect(gemspec_file.file_sha1).not_to be_nil
+        expect(gemspec_file.file_sha256).not_to be_nil
+      end
+    end
   end
 end