HP-UX RBAC Audsys Setup

1. HP-UX 11iv3 Preliminary RBAC and Auditing Setup
2012
HP-UX 11i Preliminary RBAC and Auditing
Setup
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2. HP-UX 11iv3 Preliminary RBAC and Auditing Setup
2012
Document Information
Document Name:
HP-UX 11i Preliminary RBAC Auditing Assessment and Setup
October 2012
Document Version No:
Dusan Baljevic
Prepared By:
1.1
Preparation Date:
8 October 2012
Distribution List
From
Date
Phone/Fax
Dusan Baljevic
8 October 2012
0412 041 715
To
Action*
Due Date
Phone/Fax
Inform
Action Types: Approve, Review, Inform, File, Action Required, Attend Meeting, Other (please
specify)
Modification History
Version
Owner
Date
Description
1.0
Dusan Baljevic
8 October 2012
New document
1.1
Dusan Baljevic
22 October 2012
Updates
1. Introduction.....................................................................................................................................4
2. SSH with RBAC and Keystroke Logging............................................................................................5
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3. HP-UX 11iv3 Preliminary RBAC and Auditing Setup
2012
3. RBAC Setup with Privileged Shell.....................................................................................................6
4. Basic Security Recommendations....................................................................................................7
5. HP-UX Auditing Setup......................................................................................................................8
6. Disable HP-UX Auditing..................................................................................................................10
7. View Audit Logs.............................................................................................................................11
8. Web-Based Audit Reporting..........................................................................................................13
9. General Guidelines for HP-UX Auditing.........................................................................................15
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4. HP-UX 11iv3 Preliminary RBAC and Auditing Setup
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Introduction
This document serves as a template for setting up basic Role Based Access
Control (RBAC), keystroke logging, and auditing, as per brief requirements
provided by XYZ.
The scope of the project can be extended in the future.
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5. HP-UX 11iv3 Preliminary RBAC and Auditing Setup
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SSH with RBAC and Keystroke Logging
Starting with the HP-UX RBAC B.11.31.05.01 and HP-UX SSH A.05.90 releases,
keystroke logging when enabled now will successfully create a keystroke
log file for a SSH login session. The HP-UX RBAC Keystroke logging feature
is only supported on HP-UX 11iv3.
Installation of RBAC release B.11.31.05.01 installs RBACExt and RBAC
patch:
# swlist -l product |grep -i rbac
PHCO_41859
1.0
rbac cumulative patch
RBAC
B.11.31
HP-UX Role-based Access Control
RBACExt
B.11.31.05.01 HP-UX Role-based Access Control Extensions
The steps to configure RBAC keystroke logging for SSH sessions:
•
Add libpam_keystroke.so.1 library to 'sshd' service. Note: it can be
added to other services as needed:
# vi /etc/pam.conf
...
# Session management
#
sshd
session required
sshd
session required
sshd
session optional
•
libpam_hpsec.so.1
libpam_unix.so.1
libpam_keystroke.so.1
Modify RBAC configuration file rbac.conf to support keystroke logging
and define logging location:
# vi /etc/rbac/rbac.conf
...
# Keystroke Logging enabled: If this flag is set to 1, then keystroke
# logging is enabled on the system, otherwise it is disabled.
KEY_STROKE_LOGGING = 1
# Location of keystroke log file: An administrator may specify the
# directory location in where the keystroke logs should reside.
# If this location is not specified, the default is "/var/adm/rbac".
KEY_STROKE_LOCATION = /var/adm/rbac
# Banner page logging: The banner page will be logged if the below
# flag set to 1; otherwise, it will not be captured in the log file.
# The default is to omit the banner.
KEY_STROKE_BANNERPAGE_LOG_ENABLE = 1
•
Set key filter. An example:
# vi /etc/rbac/key_filter
newadm:*:dflt:dflt:ks_all
•
Ssh into the server as user newadm and run some commands.
•
Check log file. For example, for user newadm:
# more /var/adm/rbac/klog-newadm-ssh-Mon_Oct_22_2012_12:41:16-8933
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6. HP-UX 11iv3 Preliminary RBAC and Auditing Setup
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•
2012
RBAC Setup with Privileged Shell
Create a new system administrator account and set the Shell as
/usr/bin/privsh or /usr/bin/privksh (depending on the company’s policy
of default Shells):
# groupadd wheel
# useradd -g wheel -s /usr/bin/privksh -m newadm
# passwd newadm
# roleadm assign newadm Administrator
# cat /etc/rbac/user_role
root:
Administrator
newadm: Administrator
•
Set up commands that newadm will be allowed through RBAC in command
file /etc/rbac/cmd_priv:
# vi /etc/rbac/cmd_priv
For example, enable these lines to add new users:
/usr/sbin/useradd
:0/0// :dflt :dflt :dflt :
•
:dflt
:(hpux.user.add,*)
The permissions of the RBAC command file must not be restrictive to
allow read access:
# ls -als /etc/rbac/cmd_priv
48 -r--r--r--
•
1 root
sys
18546 Feb 10
2011 /etc/rbac/cmd_priv
To test it, log in as user newadm and try to add a new user:
newadm$ useradd myfriend
privksh: useradd:
not found
newadm$ /usr/sbin/useradd myfriend
The last command is successful because full path to command is used.
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7. HP-UX 11iv3 Preliminary RBAC and Auditing Setup
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Basic Security Recommendations
Some very simple recommendations follow. More comprehensive report can be
provided as part of a separate engagement.
•
To disable direct root access unless logged via console. Set up file
/etc/securetty with one line in it:
console
•
Disable direct root access via ssh. Edit /etc/opt/ssh/sshd_config:
PermitRootLogin no
•
Disable all insecure protocols in /etc/inetd.conf.
The security can further be increased by editing /var/adm/inetd.sec.
•
To restrict who can su(1M) to root: edit /etc/default/security:
SU_ROOT_GROUP=wheel
Then, simply add all admin accounts to Unix group wheel. The name of
Unix group is arbitrary (historically set to wheel).
•
Root’s home directory should be /root, not / (which should be
restricted through permissions 700).
•
Daemon flags for inetd to set up correctly in
/etc/rc.config.d/netdaemons (flag "-p" to limit number of
processes).
•
Daemon flags for inetd to set up correctly in
/etc/rc.config.d/netdaemons (flag "-a" to enable user-level auditing
of processes).
•
Daemon flags for inetd to set up correctly in
/etc/rc.config.d/netdaemons (flag "-l" to enable logging).
•
Account root is set up with password expiration.
•
And many other possible improvements.
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HP-UX Auditing Setup
To enable auditing on the HP-UX 11i system, follow these steps:
1. To audit all users, set the following in /etc/default/security:
AUDIT_FLAG=1
Or, to enable auditing per user, the userdbset(1M) command can be
used:
# userdbset -u newadm AUDIT_FLAG=1
(enable auditing for newadm)
# userdbset –d -u newadm AUDIT_FLAG (disable auditing for newadm)
2. Create customized auditing configuration file
/etc/audit/audit_site.conf (it is one single line). The list of
events can be more comprehensive – it depends on business
requirements:
PROFILE XYZ = EVENT login, EVENT moddac, EVENT create, EVENT delete,
EVENT modaccess, EVENT open, EVENT close, EVENT admin
PROFILE Supplement = EVENT readdac, EVENT process, EVENT removable
3. To audit according to policy XYZ, enter the following command:
# audevent -P -F -r XYZ
4. Use the audevent(1M) command with no options to display a list of
events and system calls that are currently configured for auditing.
5. Set the audevent(1M) /etc/rc.config.d/auditing file:
AUDITING=1
PRI_AUDFILE=/var/.audit/audtrail
PRI_SWITCH=1000
SEC_AUDFILE=*
SEC_SWITCH=0
NTHREADS=1
AUDEVENT_ARGS1="-P -F -r XYZ"
AUDEVENT_ARGS2=""
AUDEVENT_ARGS3=""
AUDEVENT_ARGS4=""
AUDOMON_ARGS="-p 20 -t 1 -w 90 -o /var/adm/syslog/syslog.log -X
'/usr/bin/scp -R /var/.audit/audtrail* remsrv:/var/.audit/auditbackup'"
The last line above creates a specific syslog entry and then copies
audit logs to remsrv into /var/.audit/audit-backup directory
whenever a new audit trail file is created.
The maximum size of the primary audit trail (log file) is based on
observed monitoring of the activity on the server:
PRI_SWITCH=1000 (the size is in Kbytes)
6. Start the auditing system, or reboot the server:
# /sbin/init.d/auditing start
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9. HP-UX 11iv3 Preliminary RBAC and Auditing Setup
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7. The entries in /var/adm/syslog/syslog.log look like:
audit system approaching AuditFileSwitch point.
current audit trail size = 905 kilobytes.
Use -X option to schedule a task at each switch point to archive and
backup current audit trail, and make sure file system not to become
full.
audomon: auto-switch to /var/.audit/audtrail.20121022_1220 was
successful.
audomon: auto-switch to /var/.audit/audtrail.20121022_1221 was
successful.
8. To check the current auditing status, after some activity on the
server, it might look like:
# audsys
auditing system is currently on
current trail: /var/.audit/audtrail.20121022_1221
next
trail: none
statisticsafs Kb used Kb avail %
fs Kb used Kb avail %
current trail:
1000
703
30 12288000 5643048
54
next
trail: none
auditing system is actively writing to 1 file(s)
# ps -ef | grep audomon
root 3151
1 0 12:04:08 ?
0:00 /usr/sbin/audomon -p
20 -t 1 -w 90 -o /var/adm/syslog/syslog.log
# ll /var/.audit
total 0
drwx-----drwx-----drwx------
2 root
2 root
2 root
sys
sys
sys
96 Oct 22 12:04 audtrail
96 Oct 22 12:20 audtrail.20121022_1220
96 Oct 22 12:21 audtrail.20121022_1221
The audit trails (binary log files) are automatically created once
the maximum size/threshold is reached. There is no need to run a
script or cron job for it.
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10. HP-UX 11iv3 Preliminary RBAC and Auditing Setup
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Disable HP-UX Auditing
To disable auditing on the system, follow these steps:
1. Stop system auditing using the following command:
# audsys -f
2. Set the AUDITING flag to 0 in the /etc/rc.config.d/auditing file to
prevent the auditing system from starting when the system is rebooted.
3. (Optional) Stop the audomon daemon. One method:
# kill `ps -e | awk '$NFS~ /audomon/ {print $1}'`
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11. HP-UX 11iv3 Preliminary RBAC and Auditing Setup
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View Audit Logs
The audisp(1M) command will be obsolete in a future release. Invoking
/usr/sbin/auditdp -r audit_trail produces the same output as
/usr/sbin/audisp audit_trail.
The following options are available with the audisp command:
-f
-p
-c system_call
-t
-s
-u user-name
-l terminal-name
-e event-name
> file-name
Displays failed events only
Displays successful events only.
Displays the selected system call
Display events that occurred after the given time
Displays events that occurred before the given time
Displays information for a specific user
Displays information for a specific terminal
Displays information for the given event
Writes output to specified file
It can take a few minutes to prepare the record for viewing when working
with large audit logs. When viewing the audit data, be aware of the
following anomalies:
• Audit data can appear inaccurate when programs that collect data for
auditable system calls supply incorrect parameters. The audit data shows
what the user program passed to the kernel. For example, calling the kill
system call with no parameters produces unpredictable values in the
parameter section of the audit record.
• System calls that take file name arguments may not have device and inode
information properly recorded. The values will be -1 if the call does not
complete successfully.
• Auditing the superuser while changing the event or system call audit
parameters will result in a long audit record. For example, when you add
an event type to be audited, a record will be produced for each event type
and system call that has been enabled for audit, not just for the new
event type being added.
Some examples of commands:
• Display the log output on the screen:
# /usr/sbin/audisp /var/.audit/audtrail/spu0.log
• Direct the log output to /tmp/mylogoutput:
# /usr/sbin/audisp /var/.audit/audtrail/spu0.log > /tmp/mylogoutput
• View successful events only:
# /usr/sbin/audisp -p /var/.audit/audtrail/spu0.log
• View activities owned by user newadm:
# /usr/sbin/audisp -u newadm /var/.audit/audtrail.20121022_1237
• View login events only:
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12. HP-UX 11iv3 Preliminary RBAC and Auditing Setup
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# /usr/sbin/audisp -e login /var/.audit/audtrail.20121022_1220
The better command is auditdp(1M) in the newer versions of auditing. An
example for login auditing:
# auditdp -r /var/.audit/audtrail.20121022_1220 -s "+event=login"
Example of exporting auditing trail to standard output and appending the
same data into syslog:
# auditdp -r /var/.audit/audtrail.20121022_1220 -P -o follow -O sync |
/opt/audit/AudReport/bin/audit_p2l | tee -a /var/adm/syslog/syslog.log
Example of exporting auditing trail to file /tmp/myfile:
# auditdp -r /var/.audit/audtrail.20121022_1220 -P -o follow -O sync |
/opt/audit/AudReport/bin/audit_p2l >/tmp/myfile
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13. HP-UX 11iv3 Preliminary RBAC and Auditing Setup
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Web-Based Audit Reporting
Note that these scripts in /opt/audit/AudReport directory, depending on
the version of the software installed on HP-UX servers, might need minor
modifications!
Modify the Shell script /opt/audit/AudReport/bin/audreport_setup_web
# vi /opt/audit/AudReport/bin/audreport_setup_web
The following four lines had to be changed on my test server:
HTPASSWD_EXE=/opt/hpws22/apache/bin/htpasswd
APACHE_CTL=/opt/hpws22/apache/bin/apachectl
HTTPD_CONF=/opt/hpws22/apache/conf/httpd.conf
/sbin/init.d/hpws22_apache start
The original ones were:
HTPASSWD_EXE=/opt/hpws/apache/bin/htpasswd
APACHE_CTL=/opt/hpws/apache/bin/apachectl
HTTPD_CONF=/opt/hpws/apache/conf/httpd.conf
/sbin/init.d/hpws_apache start
Secondly, ensure that Apache web server is started:
# vi /etc/rc.config.d/hpws22_apacheconf
HPWS22_APACHE_START=1
Then, simply run:
# /opt/audit/AudReport/bin/audreport_setup_web
By default, the username to access the web reports is:
# cat /var/opt/audit/AudReport/.htpasswd
audreport_admin:Rd4heCHXvEWh2
# /opt/audit/AudReport/bin/audreport_generator
NOTE: HTTP_ALIAS is not specified. Assuming /audreport_web.
NOTE: REPORTS_FILENAME is not specified. Assuming index.html.
NOTE: REPORTS_LOCATION is not specified. Assuming
/var/opt/audit/AudReport.
NOTE: STYLESHEETS_LOCATION is not specified. Assuming
/opt/audit/AudReport/xslts.
NOTE: REPORT_STYLE is not specified for the report
"passwd_change_history". Assuming audreport_generic.xsl.
NOTE: REPORT_STYLE is not specified for the report "user_account_history".
Assuming audreport_generic.xsl.
NOTE: REPORT_STYLE is not specified for the report
"file_ownership_change_history". Assuming audreport_generic.xsl.
Generating reports ......
Generated reports are now available at:
http://<hostname>/audreport_web/index.html
Here is a screenshot of a web-based report:
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15. HP-UX 11iv3 Preliminary RBAC and Auditing Setup
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General Guidelines for HP-UX Auditing
• Check the audit logs according to the security policy. For example, a
security policy might state that an online audit file should be retained
for at least 24 hours and all audit records stored offline should be
retained for a minimum of 30 days.
• Review the audit log for unusual activities, such as: late hours login,
login failures, failed access to system files, and failed attempts to
perform security-relevant tasks.
• Prevent the overflow of the audit file by archiving on a regular basis.
• Ensure that when the required data retention period has ended, the logs
are retired by destroying them according to the organization's data
destruction policies.
• Revise current selectable events periodically, especially after
installing new releases of HP-UX, since new system calls are often
introduced in new releases.
• Revise audited users periodically.
• Do not follow any pattern or schedule for event or user selection.
• Audit trails (binary log files) must never be part of root file system
(/). Typically, they should be saved under /var.
• Set site guidelines. Involve users and management in determining these
guidelines.
• If the audit data volume is expected to be high, configure audit trails
on a logical volume consisting of multiple physical disks and multiple
physical I/O cards. Use the -N option with audsys command to split the
audit trail into multiple files.
• Frequently accessed data, such as production data, must be available online. Data not requiring as frequent or ready access such as back-up data
can be stored off-line. Use the auditdp command to filter on-line data to
remove unnecessary information. This enables you to keep the audit file at
a manageable size and keep the less interesting information in off-line,
backup storage. For example, use auditdp to filter only login and logout
events from one month’s audit trail. If you need to access other records,
you can recover them from off-line backup tapes.
• Ensuring the confidentiality, integrity, and availability of logs is
very important:
1
2
3
4
5
Logging mechanisms must neither be deactivated nor compromised to
provide business continuity of logging services in the event of an
incident.
Ensure that log files cannot be edited or deleted. Generally only
administrators and auditors must have access to log files for review
and management only. All privileged user (the administrator and
auditor) access must be logged and reviewed thoroughly and
frequently by others outside that user domain.
6
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Communications must be protected with mechanisms such as encryption
(for example, HP-UX IPSec and SSL).
Protect the confidentiality and integrity of log files using either
message digests or encryption or digital signatures.
Provide adequate physical protection for logging mechanisms and
stored logs by preventing unauthorized physical access.
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