Wildcard Certificates

A Wildcard SSL Certificates helps in achieving SSL encryption on multiple sub-domains with the help of a single certificate as long as the sub domains are on one same physical server, share the same second-level domain name and are under the control of a single organization.

For example, one wildcard certificate *.yourdomain.com would be able to secure the following websites :

  • www.yourdomain.com
  • secure.yourdomain.com
  • product.yourdomain.com
  • info.yourdomain.com
  • download.yourdomain.com
  • anything.yourdomain.com

However, the following will not work:

  • foo.info.yourdomain.com
  • bar.secure.yourdomain.com

These sites would require a separate certificate for each sub-domain:

  • *.info.yourdomain.com
  • *.secure.yourdomain.com

Older Browsers#

'Older' browsers don't recognize wildcard certificates and report a name conflict between the domain and the certificate.
  • IE5.5 is ok,
  • and I think IE5.0sp2 is ok.
  • Prior versions of IE will have problems and I'm not sure
  • Netscape - 7 onwards is definitely ok, and I think 6 is as well.
  • Not sure about 4.7.

More Information#

There might be more information for this subject on one of the following: ...nobody