LJK/Security Reference Manual


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VALID

Ensure that preservation of past user identification conform to policy.

Violation reports

Constraint Nature of the violation
UIC UIC found in audit logs is no longer valid
USERNAME Username found in audit logs is no longer valid

Description

The tests within this element determine whether UIC and Username values are retained (even if disabled) as long as needed to analyze audit logs and potentially to retain file ownership.
Default policy UICs and usernames must be retained when usernames are disabled. Customizing There is seldom a reason to modify the limits of this element. selector

Limits

Constraint Value Default
UIC FALSE or TRUE TRUE
USERNAME FALSE or TRUE TRUE

Exemptions

Constraint Value Parameters
UIC FALSE or TRUE <node>, <absolute-time> or <earliest-time>
USERNAME FALSE or TRUE <node>, <absolute-time> or <earliest-time>
Practical considerations Adding exemptions based on earliest-time may be appropriate for situations where use of product is introduced late in the game. The earliest-time specified cannot be later than the time at which the exemption is added.

Certain versions of VMS will fabricate UICs like [1,1], [1,3], [1,6] and Usernames like AUDIT$SERVER and DECNET, that have never existed in the Rights Database (RIGHTSLIST.DAT) or User Authorization File respectively. Since exemptions for the USAGE facility are based on time of incidents rather than on username, you may wish to have the system manager add UIC identifiers and (disabled) User Authorization File entries until you are running some future version of VMS that resolves this discrepancy.

6.10 VMS Tests

Tests in the VMS facility deal with system parameters and other system-wide security considerations which are not readily categorized otherwise.

Exemptions are based on node name.

More than in other facilities many VMS tests have to do with denial of service issues.


ACME

Ensure the set of enabled ACME Agents conforms to policy.

Violation reports

Constraint Nature of the violation
MATCH Ordered list of ACME Agents does not exactly match policy
MUSTHAVE Set of ACME Agents does not include one required by policy
MUSTLACK Set of ACME Agents includes one prohibited by policy
NOMORETHAN Set of ACME Agents includes more than those permitted by policy
NOTJUST Set of ACME Agents does not include any beyond set declared inadequate by by policy

Description

The tests within the ACME element determine whether the set of enabled ACME agents conforms to policy.
Default policy There are no restrictions. Customizing Since the test might be considerably longer than a typical DCL command line, these tests allow a command line user to progressively specify text, starting each subsequent value with the character "+". selector

Limits

Constraint Value Default
MATCH 0-511 characters none
MUSTHAVE 0-510 characters none
MUSTLACK 0-510 characters none
NOMORETHAN 0-510 characters none
NOTJUST 0-510 characters none

Exemptions

Constraint Value Parameters
MATCH 0-511 characters <node>
MUSTHAVE 0-510 characters <node>
MUSTLACK 0-510 characters <node>
NOMORETHAN 0-510 characters <node>
NOTJUST 0-510 characters <node>
Practical considerations The MATCH constraint is different than the others in that the order in which names appears is significant.

Typically a site policy will be implemented using only a few of the constraints within this element.


ACMEORLGI

Ensure the set of enabled ACME Agents and LGI callout providers conforms to policy.

Violation reports

Constraint Nature of the violation
MATCH Ordered list of ACME Agents and LGI-callout modules does not exactly match policy
MUSTHAVE Set of ACME Agents and LGI-callout modules does not include one required by policy
MUSTLACK Set of ACME Agents and LGI-callout modules includes one prohibited by policy
NOMORETHAN Set of ACME Agents and LGI-callout modules includes more than those permitted by policy
NOTJUST Set of ACME Agents and LGI-callout modules does not include any beyond set declared inadequate by by policy

Description

The tests within the ACMEORLGI element determine whether the set of enabled ACME agents and LGI callout providers conforms to policy.
Default policy There are no restrictions. Customizing Since the test might be considerably longer than a typical DCL command line, these tests allow a command line user to progressively specify text, starting each subsequent value with the character "+". selector

Limits

Constraint Value Default
MATCH 0-511 characters none
MUSTHAVE 0-510 characters none
MUSTLACK 0-510 characters none
NOMORETHAN 0-510 characters none
NOTJUST 0-510 characters none

Exemptions

Constraint Value Parameters
MATCH 0-511 characters <node>
MUSTHAVE 0-510 characters <node>
MUSTLACK 0-510 characters <node>
NOMORETHAN 0-510 characters <node>
NOTJUST 0-510 characters <node>
Practical considerations The MATCH constraint is different than the others in that the order in which names appears is significant.

Typically a site policy will be implemented using only a few of the constraints within this element.


ANNOUNCE

See if the contents of the SYS$ANNOUNCE message conform to policy.

Violation reports

Constraint Nature of the violation
CONTAINED SYS$ANNOUNCE message must be contained within the specified text
CONTAINS SYS$ANNOUNCE message must contain the specified text
MATCH SYS$ANNOUNCE message must match the specified text

Description

Compare the value of SYS$ANNOUNCE (or the file to which it points) to the specified policy text.
Default policy There is no required text. Customizing Since the message might be considerably longer than a typical DCL command line, these tests allow a command line user to progressively specify text, starting each subsequent value with the character "+". selector

Limits

Constraint Value Default
CONTAINED 0-511 characters none
CONTAINS 0-511 characters none
MATCH 0-511 characters none

Exemptions

Constraint Value Parameters
CONTAINED 0-511 characters <node>
CONTAINS 0-511 characters <node>
MATCH 0-511 characters <node>
Practical considerations The MATCH constraint is equivalent to including the same text in both the CONTAINED constraint and the MATCH constraint.

Comparison treats line-feed, carriage-return, line-feed and form-feed as equivalent to space. It also treats multiple spaces as equivalent to a single space and artifically inserts a space before and after any punctuation characters.

While the SYS$WELCOME logical name mechanism (measured by WELCOME) can be customized on a per-username basis, the SYS$ANNOUNCE logical name mechanism (measured by ANNOUNCE) lends itself better to requirements that the message stay on a screen until explicit action is taken by the user. (The explicit action being the entering of a username.)


BRKDISUSER

Determine whether the setting to disable usernames on attempted breakin conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED System parameter LGI_BRK_DISUSER is 1 in violation of policy
REQUIRED System parameter LGI_BRK_DISUSER is 0 in violation of policy

Description

System parameter LGI_BRK_DISUSER controls whether a breakin attempt causes a username to be disabled until manually reset.
Default policy By default LGI_BRK_DISUSER is prohibited. Customizing Allowing LGI_BRK_DISUSER should be done only with careful consideration of organizational politics. selector

Limits

Constraint Value Default
PROHIBITED FALSE or TRUE FALSE
REQUIRED FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>
REQUIRED FALSE or TRUE <node>
Practical considerations End users will be hostile to disabling accounts on breakin attempts unless there are adequate provisions for restoring an account to service promptly when the end user follows appropriate procedures. Therefore, before requiring that system parameter LGI_BRK_DISUSER be set to 1, be sure that you have established these procedures and that they are secure and widely published in your organization.

BUGCHKFATL

Determine whether decisions regarding crashing on Executive Mode bugchecks conform to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED System parameter BUGCHECKFATAL is enabled [1] in violation of policy
REQUIRED System parameter BUGCHECKFATAL is disabled [0] in violation of policy

Description

All Kernel Mode bugchecks crash the system, but the outcome of Executive Mode bugchecks is settable.
Default policy BUGCHECKFATAL is neither prohibited nor required. Customizing Prohibit BUGCHECKFATAL to avoid immediate denial of service in spite of bugchecks.

Require BUGCHECKFATAL to ensure that the conditions that caused each crash are recorded (in a crash dump), allowing the problem to be thoroughly analyzed. Providing that each bugcheck is analyzed this way, you should be able to resolve problems before they build to a crescendo that results in a substantial denial of service. selector

Limits

Constraint Value Default
PROHIBITED FALSE or TRUE FALSE
REQUIRED FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>
REQUIRED FALSE or TRUE <node>
Practical considerations Allowing the system to run through a bugcheck without crashing means that there will be no crash dump recorded. Without the crash dump, the problem cannot be analyzed and will probably recur.

On the other hand, even when the system is allowed to continue running through an RMS bugcheck, it will leave an error code in R2 of the BUGCHK error log entry for the failure.


BUGREBOOT

Determine whether rebooting after a crash conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED System parameter BUGREBOOT is 1 in violation of policy
REQUIRED System parameter BUGREBOOT is 0 in violation of policy

Description

System parameter BUGREBOOT determines whether VMS reboots automatically after a software crash.
Default policy Rebooting after a crash is neither prohibited nor required. Customizing If the system does not reboot automatically after a crash, there will be a denial of service until the system is manually rebooted. This denial of service might still be better than continuing operation with an uncorrected problem. selector

Limits

Constraint Value Default
PROHIBITED FALSE or TRUE FALSE
REQUIRED FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>
REQUIRED FALSE or TRUE <node>
Practical considerations Whether VMS reboots after a power failure is controlled by console hardware settings in a fashion which depends on the processor model AND NOT ON BUGREBOOT.

CHECKSUM

See if choice of checksum algorithm conforms to policy.

Violation reports

Constraint Nature of the violation
NOSHA1 SHA1 checksum algorithm is used in violation of policy
NOSIMPLE SIMPLE checksum algorithm is used in violation of policy
NOSITE SITE checksum algorithm is used in violation of policy

Description

The tests within this element determine whether an unapproved checksum algorithm is in use.
Default policy all checksum algorithms are acceptable. Customizing Change these constraints to match external standards imposed on your organization. selector

Limits

Constraint Value Default
NOSHA1 FALSE or TRUE FALSE
NOSIMPLE FALSE or TRUE FALSE
NOSITE FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
NOSHA1 FALSE or TRUE <node>
NOSIMPLE FALSE or TRUE <node>
NOSITE FALSE or TRUE <node>
Practical considerations For information on how to provide a site-specific checksum algorithm, refer to Section 9.2.3,LJK$SECURITY_SITE_CHECKSUM callback.

CLASSPROT

Determine whether mandatory access control enabling conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED System parameter CLASS_PROT is 1 in violation of policy
REQUIRED System parameter CLASS_PROT is 0 in violation of policy

Description

System parameter CLASS_PROT enables the optional SEVMS software (if it has been installed).
Default policy CLASS_PROT is neither prohibited nor required. Customizing If only some of your nodes use SEVMS, set both limits to TRUE and use exemptions as appropriate. selector

Limits

Constraint Value Default
PROHIBITED FALSE or TRUE FALSE
REQUIRED FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>
REQUIRED FALSE or TRUE <node>
Practical considerations If SEVMS is installed on certain nodes, use of DECnet by LJK/Security might be impractical, depending on the exact manner in which classifications are established.

CLUSTER

See if cluster membership conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED Cluster membership is enabled in violation of policy
REQUIRED Cluster membership is disabled in violation of policy

Description

The tests within this element determine whther cluster membership conforms to policy.
Default policy Cluster membership is neither required nor prohibited. Customizing Manipulate limits and constraints to match your organization's plan. selector

Limits

Constraint Value Default
PROHIBITED FALSE or TRUE FALSE
REQUIRED FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>
REQUIRED FALSE or TRUE <node>
Practical considerations There are many other reliability measures required to get the benefit of VMS Clusters. Constraint REQUIRED might just validate the presence of a single node cluster !


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