Subject Alternative Name (SAN) in SSL certificatesEdit

Redirected from SAN

  • Clients check the Common Name (CN), but also the Subject Alternative Names (SAN)
  • The CN should be included in among the SANs
  • This can be used to allow a single IP to support multiple domain aliases (unlike a wildcard certificate, the alternate names need not just be subdomains of the same parent domain); normally you need a separate IP per certificate because at the time the certificate is used the only unencrypted information the server has is the requested IP address
  • As you’d expect given the CA racket, getting a cert with SANs is much more expensive — an order of magnitude more — than getting a simple cert (for example, SAN-capable Thawte certs start at around $199/year); a comparison list can be found here with prices starting at just under $100/year and this page has prices starting at $60/year; overall the cheapest I’ve seen is
  • For an example of a SAN certificate in the wild, inspect the certificate from, or this website


See also