HP Traffic Director sa7220 - Manual (Page 34)

C H A P T E R 2 HP Traffic Director Server Appliances User Guide
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HTTP Header Option Fields
Both the SA7220 and the SA8200/SA8220 can make the IP address
of a requesting client available to a fulfillment server by constructing
a custom HTTP header option, with the client’s IP as the value:
HP_SOURCE_IP:
SSL-related HTTP header option fields are only used by the SA8200/
SA8220 with any SSL service. The HP_CIPHER_USED header
option is used whenever HP_SOURCE_IP is used, to provide the
name of the SSL-cipher negotiated between the SA8200/SA8220 and
the client:
HP_CIPHER_USED:
These two header fields are used only by the SA8200/SA8220 when
client authentication is in use:
HP_CLIENT_CERTIFICATE:
HP_SESSION_ID:
Because a client certificate contains information useful for client/user
authorization, the SA8200/SA8220 inserts the client certificate in the
request header before sending the request to the server. The server
can then extract the certificate from the request header and use it for
authorization or other purposes.
The client certificate is inserted in the request header only once per
session. Requests following the initial request will be sent to the
server with only the SSL-session-id in the header. The SSL-session-
id is unique for each session and allows the server to work with
multiple sessions. The client certificate is inserted in the request
header with a new SSL-session-id only when the client certificate has
been re-negotiated between theSA8200/SA8220 and the client:
• New Session/Initial Request:SA8200/SA8220 sends both the
HP_CLIENT_CERTIFICATE and HP_SESSION_ID header
options.
• Existing Session/Subsequent Requests: SA8200/SA8220 sends
only the HP_SESSION_ID header option.
The use of header option fields is an efficient way of supplying
information to the server about the client. To ease the use of this
important feature, SA7220/SA8200/SA8220 allows customization of
all the above header option field names. For more information, see
Chapter 5.