The document discusses SSL certificates, particularly focusing on wildcard SSL certificates, which can secure multiple domains. It explains the functions and significance of SSL certificates for encrypting sensitive information and verifying server identity, while also highlighting the limitations of wildcard SSL, Subject Alternative Names (SAN), and Server Name Indication (SNI). Additionally, it provides references for further reading on SSL certification and its various types.

1. Three things for
Wildcard SSL certs
Satoshi Tashiro /HDE, Inc. SEG

2. Agenda
- Relearn SSL certificate
- Three things for SSL certs
- Wildcard SSL certificate
- Subject Alternative Name
- Server Name Indication

3. Relearn SSL certificate
What is an SSL certificate?
SSL Certificates bind a digitally cryptographic
key to an organization’s details.
SSL certificates are to encrypt
your sensitive information.
(e.g. credit card, login password)

4. Relearn SSL certificate
Why use SSL certificate?
SSL certificate provides authentication.
You are sending information to the right server
and not to a criminal’s server.

5. Wildcard SSL certificate
What is an Wildcard SSL cert ?
A normal SSL certify one domain.
A wildcard SSL certify multi domain.

6. Wildcard SSL certificate
Be careful wildcard level
a. *.example.com
b. w*.example.com
c. *.*.example.com
d. www.*.example.com
<- RFC definition. work major browser.
<- RFC definition. maybe work.
<- RFC not definition. work on some browser.
<- RFC not definition. maybe not work.

7. Subject Alternative Name
If you want certification
multiple domain by one certs,
use SAN certs.

8. Subject Alternative Name
Demerit of SAN
- SAN was not supported all browser.
- Very high cost
e.g.)
example.com
test.com
aaa.com
hoge.com
foo.bar
another.domain
$29.88
$12.88 x domains !!!

9. Server Name Indication
A client indicates which hostname it is
attempting to connect to at the start of the
handshaking process.

10. Server Name Indication
Demerit of SNI
- SNI was not supported all
Browser/Server/Library.
- Browser : around Vista (IE/Firefox/Chrome/Safari)
- Server : Apache 2.2.12 + mod_ssl
- Library : openssl 0.9.8j
-> Next generation technology ... ?

11. References
- GlobalSign: What is an ssl certificate
https://www.globalsign.com/en/ssl-information-center/what-is-an-ssl-certificate/
- SSL Shoper: Why SSL? The Purpose of using SSL Certificates
https://www.sslshopper.com/why-ssl-the-purpose-of-using-ssl-certificates.html
- namecheap: about postitivessl multi domain (SAN cert)
https://www.namecheap.com/security/ssl-certificates/comodo/positivessl-multi-domain.aspx
- Wikipedia: Wildcard certificate
http://en.wikipedia.org/wiki/Wildcard_certificate
- Wikipedia: SubjectAltName
http://en.wikipedia.org/wiki/SubjectAltName
- Wikipedia: Server Name Indication
http://en.wikipedia.org/wiki/Server_Name_Indication
Paul's Journal: TLS Server Name Indication.
https://journal.paul.querna.org/articles/2005/04/24/tls-server-name-indication/