HP System Management Homepage-Software - Manual (Page 52)

Timestamps are used in Kerberos to avoid replication attacks. The clock skew among machines cannot
exceed a specific limit.
2. The TGS decrypts the authenticator and sends two new messages back to the client:
•
The client-to-server ticket received from the TGS
•
Another authenticator, made up of the client’s ID and the current timestamp, encrypted with the
client/server session key
3. The service decrypts the client-to-server ticket with its own secret key and sends the client a message
with the received timestamp plus one, confirming its true identity. This message is encrypted with the
client/server session key.
4. The client decrypts the message and checks the timestamp. If it is correct, requests may be issued to the
service and it sends responses back as expected.
HP SMH Kerberos Authentication
HP SMH provides Kerberos Single Sign-On (SSO) , allowing users in a Kerberos realm to log in without
entering a user name and password in the Sign In page. If an allowed user accesses HP SMH and has valid
Kerberos credentials, the Home page appears inside HP SMH.
Kerberos authentication is done using the special URL /proxy/Kerberos in HP SMH. By accessing the
URL, SMH looks for Kerberos credentials in the request and perform user authentication.
If the user does not have valid Kerberos credentials or if an error occurs during the authentication process,
the Sign In page appears, showing an error message. For example, if the clock skew among the machines
involved in authentication is too large, you receive an error message and are taken to the Sign In page.
Kerberos authentication does not work on the following local access situations:
•
Accessing HP SMH from the machine where the KDC (AD) is installed
•
Accessing HP SMH from the machine where HP SMH is installed
When an authentication error occurs, the system administrator should check the SMH HTTP server error log
to obtain more information about the error.
For example, when the clock skew among the machines is too large, the following log message is written:
Thu Jun 25 16:55:09 2009] [error] client 2001:db8:c18:1:b8ca:fcdf:d49d:b5c6]
mod_spnego: Kerberos SSO (QueryContextAttributes) failed; SSPI: The function
requested is not supported\r\n(-2146893054) .
The following levels of user authorizations are available:
•
Administrator Users with Administrator access can view all information provided through HP SMH.
The appropriate default user group, Administrators for Windows operating systems and root for HP-UX
and Linux, always has administrative access.
•
Operator Users with Operator access can view and set most information provided through HP SMH.
Some web applications limit access to the most critical information to administrators only.
•
User Users with User access can view most information provided through HP SMH. Some web
applications restrict viewing of critical information from individuals with User access.
To enable or disable Kerberos and add groups to the allowed Kerberos group list, complete the following
steps for each level of access.
Kerberos support is provided on a per-user basis.
Kerberos Administrator
To add a Kerberos Administrator:
1. Select Settings from the menu.
2. In the System Management Homepage box, click the Security link.
3. Click the Kerberos Authorization link.
4. In the Kerberos Configuration area, select the box beside Enable Kerberos Support.
52 The Settings Page