追加のHTTP固有のRFCなど、ApacheおよびSNIの最新情報については、Apache Wikiを参照してください。
FYsI：「1つのIP上の複数の（異なる）SSL証明書」は、TLSアップグレードの魔法によってもたらされます。新しいApacheサーバー（2.2.x）と比較的最近のブラウザで動作します（私の頭の上のバージョンを知りません）。
RFC 2817（HTTP / 1.1内のTLSへのアップグレード）には詳細がありますが、基本的には多くの人々（大多数ではないにしても）に有効です。ただし
、opensslのs_clientコマンド（または「古い」ブラウザー）を使用して、古いファンキーな動作を再現できます。
編集して追加：curlopensslよりもここで何が起こっているかをよりよく示すことができます：
SSLv3
mikeg@flexo% curl -v -v -v -3 https://www.yummyskin.com
* About to connect() to www.yummyskin.com port 443 (#0)
* Trying 69.164.214.79... connected
* Connected to www.yummyskin.com (69.164.214.79) port 443 (#0)
* successfully set certificate verify locations:
* CAfile: /usr/local/share/certs/ca-root-nss.crt
CApath: none
* SSLv3, TLS handshake, Client hello (1):
* SSLv3, TLS handshake, Server hello (2):
* SSLv3, TLS handshake, CERT (11):
* SSLv3, TLS handshake, Server key exchange (12):
* SSLv3, TLS handshake, Server finished (14):
* SSLv3, TLS handshake, Client key exchange (16):
* SSLv3, TLS change cipher, Client hello (1):
* SSLv3, TLS handshake, Finished (20):
* SSLv3, TLS change cipher, Client hello (1):
* SSLv3, TLS handshake, Finished (20):
* SSL connection using DHE-RSA-AES256-SHA
* Server certificate:
* subject: serialNumber=wq8O9mhOSp9fY9JcmaJUrFNWWrANURzJ; C=CA;
O=staging.bossystem.org; OU=GT07932874;
OU=See www.rapidssl.com/resources/cps (c)10;
OU=Domain Control Validated - RapidSSL(R);
CN=staging.bossystem.org
* start date: 2010-02-03 18:53:53 GMT
* expire date: 2011-02-06 13:21:08 GMT
* SSL: certificate subject name 'staging.bossystem.org'
does not match target host name 'www.yummyskin.com'
* Closing connection #0
* SSLv3, TLS alert, Client hello (1):
curl: (51) SSL: certificate subject name 'staging.bossystem.org'
does not match target host name 'www.yummyskin.com'
TLSv1
mikeg@flexo% curl -v -v -v -1 https://www.yummyskin.com
* About to connect() to www.yummyskin.com port 443 (#0)
* Trying 69.164.214.79... connected
* Connected to www.yummyskin.com (69.164.214.79) port 443 (#0)
* successfully set certificate verify locations:
* CAfile: /usr/local/share/certs/ca-root-nss.crt
CApath: none
* SSLv3, TLS handshake, Client hello (1):
* SSLv3, TLS handshake, Server hello (2):
* SSLv3, TLS handshake, CERT (11):
* SSLv3, TLS handshake, Server key exchange (12):
* SSLv3, TLS handshake, Server finished (14):
* SSLv3, TLS handshake, Client key exchange (16):
* SSLv3, TLS change cipher, Client hello (1):
* SSLv3, TLS handshake, Finished (20):
* SSLv3, TLS change cipher, Client hello (1):
* SSLv3, TLS handshake, Finished (20):
* SSL connection using DHE-RSA-AES256-SHA
* Server certificate:
* subject: C=CA; O=www.yummyskin.com; OU=GT13670640;
OU=See www.rapidssl.com/resources/cps (c)09;
OU=Domain Control Validated - RapidSSL(R);
CN=www.yummyskin.com
* start date: 2009-04-24 15:48:15 GMT
* expire date: 2010-04-25 15:48:15 GMT
* common name: www.yummyskin.com (matched)
* issuer: C=US; O=Equifax Secure Inc.; CN=Equifax Secure Global eBusiness CA-1
* SSL certificate verify ok.
