HP-UX AAA Server A.08.01 administrator's guide (T1428-90072, May 2010)

Table Of Contents
# Enabled or Disabled
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Fast Re-Authentication
Fast re-authentication is a an optional EAP-SIM and EAP-AKA feature. This feature is
used to refresh the previous authentication periodically. A fast re-authentication, if
applicable, occurs shortly after a full authentication or an earlier fast re-authentication.
The Fast-Reauth-Id-Lifetime parameter specifies a lifetime for a fast
re-authentication identity, in seconds. If a fast re-authentication identity is assigned,
but is not used within this period of time, the fast re-authentication identity and the
associated full authentication context expire.
The HP-UX AAA Server generates a fast re-authentication identity, which is 10
characters long, consisting of the fast re-authentication identity prefix 3, followed by
nine random characters from the 31 character set consisting of the upper-case characters,
without vowels, and ending with 10 digits: 0-9, that is
{BCDFGHJKLMNPQRSTVWXYZ0123456789}.
As there are 31 choices for each of the nine random characters, there are then 31
9
different identities, or, more than 26 trillion fast re-authentication identities of all
permanent identities.
Selecting only uppercase characters for the server-generated re-authentication identities
allows case-insensitive database lookups.
The server sends a fast re-authentication identity to the client, which includes a realm.
Before generating a fast re-authentication identity, the server checks whether the total
length of the name@realm string exceeds 253 characters, which is the maximum length
of a User-Name attribute value. If it exceeds the maximum length, the server does not
generate a reauth identity. As the name portion of the fast re-authentication identity
is 10 characters, this problem occurs only if the realm is greater than 242 characters.
The realm is either the configured fast reauth realm or the realm from the permanent
identity. A fast reauth realm can be configured for targeting a fast reauth authentication
request to the specific server that generated the fast re-authentication identity.
Configuring for Fast Re-Authentication
This section addresses the following topics:
“Configuring for Fast Re-Authentication in EAP.authfile” (page 248)
“Configuring for Fast Re-Authentication in aaa.config File” (page 251)
Configuring for Fast Re-Authentication in EAP.authfile
To use fast re-authentications, the realm configuration in the EAP-Type SIM{} or
EAP-Type AKA{} block in EAP.authfile must specify the parameters described in
Table 17-7.
248 Configuring EAP-SIM and EAP-AKA Authentication Methods