Generating SSL Certificate for Nginx in XC_VM

This guide explains how to create a self-signed SSL certificate to enable secure HTTPS connections for the built-in Nginx server in the XC_VM project.

Note: A fresh install already generates a unique self-signed certificate automatically (the installer runs openssl and writes server.key/server.crt into bin/nginx/conf/ before Nginx starts), and CertbotCronJob later replaces it with a real Let's Encrypt certificate. Follow this guide only to regenerate or replace the certificate manually.

---

Overview

SSL (Secure Sockets Layer) encrypts the connection between client and server, ensuring data confidentiality and user trust.
This tutorial shows how to create a self-signed SSL certificate for the embedded Nginx server in the XC_VM project.

---

Configuration Location

All SSL-related files (key, certificate, and config) are stored in:

/home/xc_vm/bin/nginx/conf

Navigate to this directory before proceeding:

cd /home/xc_vm/bin/nginx/conf

---

Step 1. Generate Private Key

Generate a 2048-bit RSA private key:

openssl genrsa -out server.key 2048

After execution, the file server.key will appear — this is your private key.
Keep it strictly confidential — it is used to sign the SSL certificate.

---

Step 2. Create server.cnf Configuration File

Create a configuration file containing certificate parameters:

cat > server.cnf << EOF
[req]
distinguished_name = req_distinguished_name
x509_extensions = v3_req
prompt = no

[req_distinguished_name]
C = RU
ST = Moscow
L = Moscow
O = XC_VM
OU = XC_VM
CN = XC_VM

[v3_req]
keyUsage = keyEncipherment, dataEncipherment
extendedKeyUsage = serverAuth
subjectAltName = @alt_names

[alt_names]
DNS.1 = XC_VM
EOF

Parameter explanation:

Field	Value	Purpose
C	RU	Country
ST	Moscow	State/Province
L	Moscow	City/Locality
O	XC_VM	Organization
OU	XC_VM	Organizational Unit
CN	XC_VM	Common Name (primary hostname)
DNS.1	XC_VM	Subject Alternative Name (SAN)

Tip: For real domain names, replace DNS.1 = XC_VM with your actual domain (e.g., DNS.1 = panel.example.com) to avoid browser warnings.

---

Step 3. Generate Self-Signed SSL Certificate

Generate the certificate using the private key and configuration file:

openssl req -new -x509 -key server.key -out server.crt -days 3650 -config server.cnf

Explanation:

• -new -x509 — creates a new self-signed certificate
• -days 3650 — certificate validity period (10 years)
• -config server.cnf — uses the custom configuration
• Result: server.crt file containing the public certificate

---

Final Files

After completing all steps, the following files should be present in /home/xc_vm/bin/nginx/conf:

File	Purpose
server.key	Private key
server.crt	Self-signed SSL certificate
server.cnf	Certificate configuration file

---

Result

Your XC_VM Nginx server is now accessible via HTTPS using the newly created self-signed certificate.
Browsers will display a “not trusted” warning — this is expected behavior for self-signed certificates.

---

Notes

• Self-signed certificates are suitable for internal use or testing only.
• For public-facing domains, use certificates from trusted CAs (e.g., Let's Encrypt).
• If you change the Domain/hostname (CN or DNS.1), you must regenerate the certificate.
• To inspect the generated certificate:

openssl x509 -in server.crt -text -noout

---