Secure Your Synology NAS with Let‘s Encrypt Certificates

Let‘s Encrypt is a free, automated certificate authority that allows you to generate trusted SSL/TLS certificates to encrypt communication between your Synology NAS and users. By enabling HTTPS with Let’s Encrypt certificates, you can securely access DSM and host websites on your Synology NAS.

In this comprehensive guide, I‘ll walk you through the entire process of setting up Let‘s Encrypt on Synology step-by-step.

Prerequisites for Using Let‘s Encrypt

Before starting, your Synology NAS must meet these requirements to use Let’s Encrypt:

• Synology DSM 6.0 or later
• A registered domain name pointing to your Synology NAS public IP address
• Ports 80 and 443 open on your router for external access to your Synology NAS

Port 80 is required for the HTTP challenge to verify domain ownership. And port 443 handles secure HTTPS traffic.

If you don‘t have a registered domain, you can use Synology‘s free DDNS service to create a domain for your NAS. However, I recommend purchasing a custom domain for increased security and professionalism.

Okay, with that out of the way, let‘s start securing your NAS!

Obtaining Let‘s Encrypt Certificate for DDNS Hostname

Here‘s how to create a free SSL certificate from Let‘s Encrypt for a Synology DDNS hostname:

1. Login to your Synology NAS DSM

2. Go to Control Panel > External Access > DDNS

3. Click Add to register a new DDNS hostname

   • Select Synology DDNS from Provider dropdown
   • Enter your desired Hostname
   • Choose a Domain name from available list

4. Check Get certificate from Let‘s Encrypt and set as default

5. Click OK and login with your Synology account credentials

6. Wait several minutes for Synology to automatically obtain, install, and apply the SSL certificate for your DDNS hostname.

That‘s it! Let‘s Encrypt has issued a free certificate securing your DDNS hostname hosted on your Synology NAS.

To confirm, you can browse to https://yourddnshostname:5001 and will see Padlock icon indicating active HTTPS with a valid certificate.

Obtaining Certificate for Custom Domain

Follow this method to add a Let‘s Encrypt SSL certificate to your regular custom domain pointing to your Synology NAS:

1. Login to DSM, go to Control Panel > Security > Certificate
2. Click Add > Get Certificate from Let‘s Encrypt
3. Check Set as default certificate (optional)
4. Enter your registered Domain name and admin Email address
5. Click Next and wait several minutes for certificate generation process
6. Your custom domain now has an automatically generated and installed trusted SSL certificate from Let‘s Encrypt!

Repeat above steps to add Let’s Encrypt certificates for any other additional domains hosted on your Synology NAS.

Setting Default Certificate for NAS

Your Synology NAS uses a default SSL certificate to encrypt DSM admin access at https://NAS_IP:5001 and several internal services.

Here is how to configure any installed certificate as the nas-wide default certificate:

1. Go to Control Panel > Security > Certificate
2. Select your desired certificate you want to make default
3. Click Edit and check Set as default certificate
4. Click OK to save changes

Now navigate to your NAS IP on HTTPS port 5001 to see the updated default certificate in action securing DSM admin console access.

Assigning Certificates to Specific Services

Additionally, you can assign unique Let‘s Encrypt certificates to individual services hosted on your Synology NAS:

1. Go to Control Panel > Security > Certificate
2. Click Settings button
3. Scroll down and edit Certificate dropdown for each service as desired
4. Click OK to apply unique SLL certificate assignments per service

For example, you could add distinct certificates from Let‘s Encrypt to secure your Photo Station, Mail Server, Website, Chat services etc. individually.

Automating Certificate Renewals

Let‘s Encrypt certificates are only valid for 90 days. But don‘t worry, Synology conveniently auto-renews your certificates automatically well before expiration, allowing you to enjoy seamless HTTPS without interruptions.

However, you must have ports 80 and 443 remaining externally accessible for the renewal process to successfully complete every 90 days.

If auto-renewal ever fails, DSM will display warnings to prompt you to manually renew your Let‘s Encrypt certificates.

Conclusion

I hope this detailed, easy-to-follow guide was helpful setting up free trusted SSL certificates from Let‘s Encrypt on your Synology NAS.

Here‘s a quick recap of what we covered:

• Prerequisites for using Let’s Encrypt on Synology
• Obtaining certs for DDNS hostnames and custom domains
• Setting default certificate protecting core NAS services
• Assigning unique certificates to individual apps and services
• Automating cert renewals

Using Let‘s Encrypt SSL certificates is crucial to securely access and manage your Synology NAS, websites, and services from anywhere. Implementing encryption best practices with HTTPS should be an essential part of your NAS security strategy.

Let me know if you have any other questions down in comments!