---
title: "Do I need a client certificate?"
source_url: https://dev.digicert.com/trustcore-sdk/nanossl/faqs/do-i-need-a-client-certificate.html
---

**Question:** My client device returns a certificate with a length of 0 when the server asks for a certificate. Will this be a problem for my NanoSSL server?

**Answer:** Zero length certificates are not a problem because the client certificate is optional. This is the case even with mutual authentication enabled, although it is possible to make the client certificate mandatory.