How Does a SAN Certificate Work?
How Does a SAN Certificate Work?
🛡️ Advanced Guide to SAN SSL Certificates
Protect multiple domains with one certificate. Discover what most people don’t know.
🌐 What is a SAN SSL Certificate?
SAN stands for Subject Alternative Name — a powerful SSL/TLS certificate extension that allows you to secure multiple domains and subdomains under one single certificate.
🔐 Example:
A single SAN certificate can cover:
🎯 What is it used for?
🔄 Unified security: Centralizes SSL management across many sites.
📉 Cost-effective: Cheaper than buying separate certificates for each domain.
🛠️ Simplifies infrastructure: Ideal for shared servers, SaaS, Exchange, IIS, NGINX, etc.
🚀 HTTP/2 and SNI friendly: Load multiple secure sites using only one public IP address.
🧠 Advanced Tricks You Won’t Find Elsewhere
🔄 1. Reuse SAN for Multi-Tenant Architectures
In SaaS environments, SAN allows you to secure custom subdomains for each client:
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client1.myapp.com client2.myapp.com
➡ No need to issue a new certificate per customer.
⚠️ Caution: All SANs are visible in the certificate. Don’t use this for sensitive subdomains.
🌐 2. Combine Global Domain Coverage
You can use SAN to secure international domains in one shot:
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mybrand.com mybrand.com.mx mybrand.co mybrand.cl mybrand.ar
Simplify global brand security with one certificate.
🧩 3. Secure Entire Brand Ecosystems
Perfect for enterprise groups with multiple brands:
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brandA.com brandB.org brandC.net
You get consolidated renewal dates and simplified compliance (PCI DSS, HIPAA, SOC2).
📈 4. Scale up to 100 domains
Most major CAs (including GlobalSign) allow up to 100 SANs per certificate.
💡 Tips to manage this:
Use automation to generate CSR and install certificates.
Set up alerts to monitor expirations and avoid downtime.
Renew early to avoid bulk reconfigurations.
🔐 5. Protect APIs, Mail Servers, and Internal Tools
Secure the following endpoints under one SAN cert:
You can mix internal and public services in the same cert.
❌ When Not to Use SAN
SituationBetter AlternativeYou need full domain privacyIndividual certificatesYou have over 100 subdomainsWildcard + automation (e.g., ACME)Each domain is owned by a different clientSeparate certs per customerYour domains change frequentlyACME-based dynamic issuance
🔬 How to View SANs in a Certificate
Terminal:
bash
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openssl x509 -in certificate.crt -text -noout | grep -A1 "Subject Alternative Name"
Browser:
Click 🔒 → Certificate → Details → Subject Alternative Name
🔒 Security and Compliance
SAN SSL certificates issued by GlobalSign, available through SSLFor.com, meet strict security standards:
🔐 SHA-2 (SHA-256) encryption
📜 CAB Forum compliance
⚙️ FIPS 140-2 compatibility
🕵️ WebTrust audit-ready
Available validation levels:
DV (Domain Validation)
OV (Organization Validation)
EV (Extended Validation)
⚙️ Tech Compatibility
SAN SSL certificates work seamlessly with:
Apache, NGINX, IIS, Exchange, Zimbra, Tomcat, etc.
Load balancers and cloud platforms (AWS, Azure, GCP)
HTTP/2 + SNI support
All major mobile, desktop, and server OS/browsers
🧠 Bonus: Use one SAN cert with many domains behind a load balancer (like AWS ELB) without IP duplication.
🛒 Where to Buy SAN SSL Certificates?
You can get them from:
🔗 SSLFor.com
Official GlobalSign Partner for North America and Latin America
✅ Spanish & English support
✅ Enterprise-level deployment options
✅ DV, OV & EV certificates available
✅ Tailored solutions for SaaS and web agencies
✅ Fast issuance and validation assistance
✅ Final Verdict: Should You Use SAN?
Yes, if you manage:
Multiple domains or subdomains
SaaS platforms with custom client URLs
International websites
Enterprise brands under a common umbrella
SAN SSL saves time, cuts cost, and boosts security.
💼 Recommended for:
Agencies & developers
SaaS platforms
Cloud architects
Managed service providers
Corporate IT departments