How to Generate the Certificate Signing Request (CSR) for Wildcard SSL

Generating a Certificate Signing Request (CSR) for Wildcard SSL Certificates requires specific formatting that differs from standard SSL Certificates.

The key difference lies in how you specify the domain name - understanding this distinction ensures your Wildcard SSL Certificate will properly secure all your subdomains.

What Makes Wildcard SSL Certificates Different

Wildcard SSL Certificates secure your main domain and unlimited first-level subdomains with a single SSL Certificate.

Instead of purchasing separate SSL Certificates for each subdomain like shop.example.com, mail.example.com, and blog.example.com, one Wildcard SSL Certificate covers them all. This makes them particularly cost-effective for businesses running multiple subdomains.

Trustico® offers Wildcard SSL Certificates in both Domain Validation (DV) and Organization Validation (OV) options.

These SSL Certificates provide the same encryption strength as standard SSL Certificates while simplifying management across your entire subdomain infrastructure.

The Critical Difference : Using the Wildcard Asterisk

When generating a CSR for a Wildcard SSL Certificate, the Common Name field must include an asterisk (*) followed by a period before your domain name.

For example, if your domain is example.com, you would enter *.example.com as the Common Name. This asterisk tells the Certificate Authority (CA) to issue an SSL Certificate that covers all subdomains at that level.

This formatting is essential - without the asterisk, you'll receive a standard SSL Certificate that only covers the specific domain you entered.

Common mistakes include forgetting the period after the asterisk or placing the asterisk in the wrong position. The correct format is always *.yourdomain.com, never *yourdomain.com or www.*.yourdomain.com.

Information Required for Your Wildcard CSR

Apart from the wildcard-formatted Common Name, the rest of the CSR generation process remains standard.

You'll need your organization's legal name, address, and contact information. For Organization Validation (OV) SSL Certificates, this information must match your official business records exactly.

The organizational information becomes part of your SSL Certificate and cannot be changed.

Double-check all details before submitting your Certificate Signing Request (CSR) to avoid validation delays. Trustico® validates this information during the issuance process to ensure SSL Certificate authenticity.

Where to Generate Your Wildcard CSR

Most web servers and hosting control panels include CSR generation tools that support wildcard formatting. Trustico® also offers online tools that are able to be utilized for generating a new Certificate Signing Request (CSR). Our SSL Certificate Tools are available at tools.trustico.com.

Whether you're using Apache, Nginx, Microsoft IIS, or control panels like cPanel or Plesk, the process typically involves entering your organizational information and ensuring the Common Name includes the wildcard prefix.

For those comfortable with command-line tools, OpenSSL remains the most universal option for CSR generation.

The key point is ensuring that whatever method you use, you specify *.yourdomain.com in the Common Name field to generate a proper Wildcard CSR.

Validation Options for Wildcard SSL Certificates

Trustico® provides Wildcard SSL Certificates with two validation levels, each suited to different business needs.

Domain Validation (DV) Wildcard SSL Certificates offer the fastest issuance, typically within minutes.

These verify domain ownership through e-mail, DNS record, or file validation. They're ideal for internal applications, development environments, or situations where quick deployment matters more than displaying organizational credentials.

Organization Validation (OV) Wildcard SSL Certificates include business verification, displaying your company name in the SSL Certificate details.

This additional validation provides greater trust for customer-facing websites and e-commerce platforms. The validation process typically takes 1-3 business days and includes verification of your business registration and contact details.

Note that Extended Validation (EV) is not available for Wildcard SSL Certificates due to industry security standards. If you need EV validation for your main domain, consider combining an EV Single Site SSL Certificate with a DV or OV Wildcard SSL Certificate for your subdomains.

Benefits of Choosing Wildcard SSL Certificates

Wildcard SSL Certificates simplify SSL Certificate management significantly, especially for growing businesses.

Instead of tracking multiple SSL Certificates with different expiration dates, you manage just one. When you add new subdomains, they're automatically covered without purchasing additional SSL Certificates.

Cost savings become substantial when securing multiple subdomains. Rather than purchasing individual SSL Certificates for each subdomain, one Wildcard SSL Certificate from Trustico® covers them all. This typically becomes cost-effective with as few as three subdomains.

The same Wildcard SSL Certificate can be installed on multiple servers if your subdomains are distributed across different machines.

This flexibility makes Wildcard SSL Certificates particularly valuable for load-balanced environments or when subdomains are hosted on separate servers.

Important Considerations for Wildcard SSL Certificates

While Wildcard SSL Certificates offer many advantages, understanding their limitations helps in making the right choice.

They only secure one level of subdomains. An SSL Certificate for *.example.com secures shop.example.com but not checkout.shop.example.com. For multi-level subdomains, you'd need additional Wildcard SSL Certificates or a Multi Domain SSL Certificate.

Some Certificate Authorities (CAs) automatically include the base domain (example.com) with a Wildcard SSL Certificate for *.example.com, while others require you to specify it separately. Trustico® offers this inclusion free of charge and will add this throughout the ordering process automatically.

All subdomains share the same Private Key, which means if the key is compromised, all subdomains are affected. This makes proper key security especially important. However, the convenience and cost savings typically outweigh this consideration for most organizations.

Making the Right Choice for Your Business

Wildcard SSL Certificates from Trustico® provide an efficient solution for securing multiple subdomains under a single domain.

The key to successful implementation is understanding the wildcard formatting requirement during CSR generation - ensuring you use *.yourdomain.com as the Common Name.

Whether you choose Domain Validation (DV) for quick deployment or Organization Validation (OV) for enhanced trust indicators, Trustico® offers Wildcard SSL Certificates to match your security requirements and budget.

Our support team can assist with validation questions and help ensure your CSR is properly formatted for wildcard coverage.

Consider your current and future subdomain needs when deciding between Wildcard SSL Certificates and individual SSL Certificates. If you're running or planning to run multiple subdomains, the management simplicity and cost savings of a Wildcard SSL Certificate make it the practical choice for most businesses.