RFC 2109 (rfc2109) - Page 2 of 21
HTTP State Management Mechanism
Alternative Format: Original Text Document
RFC 2109 HTTP State Management Mechanism February 1997
Hosts names can be specified either as an IP address or a FQHN
string. Sometimes we compare one host name with another. Host A's
name domain-matches host B's if
* both host names are IP addresses and their host name strings match
exactly; or
* both host names are FQDN strings and their host name strings match
exactly; or
* A is a FQDN string and has the form NB, where N is a non-empty name
string, B has the form .B', and B' is a FQDN string. (So, x.y.com
domain-matches .y.com but not y.com.)
Note that domain-match is not a commutative operation: a.b.c.com
domain-matches .c.com, but not the reverse.
Because it was used in Netscape's original implementation of state
management, we will use the term cookie to refer to the state
information that passes between an origin server and user agent, and
that gets stored by the user agent.
3. STATE AND SESSIONS
This document describes a way to create stateful sessions with HTTP
requests and responses. Currently, HTTP servers respond to each
client request without relating that request to previous or
subsequent requests; the technique allows clients and servers that
wish to exchange state information to place HTTP requests and
responses within a larger context, which we term a "session". This
context might be used to create, for example, a "shopping cart", in
which user selections can be aggregated before purchase, or a
magazine browsing system, in which a user's previous reading affects
which offerings are presented.
There are, of course, many different potential contexts and thus many
different potential types of session. The designers' paradigm for
sessions created by the exchange of cookies has these key attributes:
1. Each session has a beginning and an end.
2. Each session is relatively short-lived.
3. Either the user agent or the origin server may terminate a
session.
4. The session is implicit in the exchange of state information.
Kristol & Montulli Standards Track