1 files changed, 33 insertions, 0 deletions
diff --git a/app/models/concerns/redactable.rb b/app/models/concerns/redactable.rb
new file mode 100644
index 00000000000..5ad96d6cc46
--- /dev/null
+++ b/app/models/concerns/redactable.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+# This module searches and redacts sensitive information in
+# redactable fields. Currently only unsubscribe link is redacted.
+# Add following lines into your model:
+#
+#     include Redactable
+#     redact_field :foo
+#
+module Redactable
+  extend ActiveSupport::Concern
+
+  UNSUBSCRIBE_PATTERN = %r{/sent_notifications/\h{32}/unsubscribe}
+
+  class_methods do
+    def redact_field(field)
+      before_validation do
+        redact_field!(field) if attribute_changed?(field)
+      end
+    end
+  end
+
+  private
+
+  def redact_field!(field)
+    text = public_send(field) # rubocop:disable GitlabSecurity/PublicSend
+    return unless text.present?
+
+    redacted = text.gsub(UNSUBSCRIBE_PATTERN, '/sent_notifications/REDACTED/unsubscribe')
+
+    public_send("#{field}=", redacted) # rubocop:disable GitlabSecurity/PublicSend
+  end
+end