Understanding DIT Content Rules

DIT content rules provide a mechanism for defining the content that can appear in an entry. At most one DIT content rule can be associated with an entry based on its structural object class. If such a rule exists for an entry, then it works in conjunction with the object classes contained in that entry to define which attribute types must, may, and must not be present in the entry, as well as which auxiliary classes that it may include.

The following sections describe DIT content rules:

• DIT Content Rule Description Format

• DIT Content Rule Implementation

DIT Content Rule Description Format

The DIT content rule description format is described in RFC 4512, section 4.1.6, as shown here:

DITContentRuleDescription = LPAREN WSP
numericoid                 ; object identifier
[ SP "NAME" SP qdescrs ]   ; short names (descriptors)
[ SP "DESC" SP qdstring ]  ; description
[ SP "OBSOLETE" ]          ; not active
[ SP "AUX" SP oids ]       ; auxiliary object classes
[ SP "MUST" SP oids ]      ; attribute types
[ SP "MAY" SP oids ]       ; attribute types
[ SP "NOT" SP oids ]       ; attribute types
extensions WSP RPAREN      ; extensions

The DIT content rule description includes these elements:

numericoid

The numeric OID of the structural object class with which the DIT content rule is associated. Although the specification requires a numeric OID, this numericoid should match the OID specified for the associated object class, so if the object class OID was non-numeric, then this OID should be as well.

NAME

An optional set of human-readable names used to refer to the DIT content rule. If there is a single name, then it should be enclosed in single quotes. If there are multiple names, then they should each be enclosed in single quotes separated by spaces, and the entire set of names should be enclosed in parentheses.

DESC

An optional human-readable description. If a description is provided, then it should be enclosed in single quotation marks.

OBSOLETE

An optional OBSOLETE flag that can be used to indicate whether the DIT content rule is active. If a DIT content rule is marked as OBSOLETE, then it should not be in effect within Oracle Unified Directory.

AUX

An optional list of auxiliary object classes that can be present in entries with the associated structural class. If no values are provided, then such entries are not allowed to have any auxiliary object classes. Values should be specified as one or more of the names or OIDs of the allowed auxiliary classes. If multiple auxiliary classes are allowed, then separate them by spaces and dollar signs, and enclose the entire set of names in parentheses.

MUST

An optional list of attribute types that are required to be present in entries with the associated structural class. This is in addition to the attribute types required by the object classes included in the entry, and these additional attribute types do not need to be allowed by any of those object classes. Values should be specified as one or more of the names or OIDs of the required attribute types. If multiple attribute types are required, then separate them by spaces and dollar signs, and enclose the entire set of required attribute types in parentheses.

MAY

An optional list of attribute types that can optionally be present in entries with the associated structural class. This is in addition to the attribute types allowed by the object classes included in the entry. Values should be specified as one or more of the names or OIDs of the optional attribute types. If there are multiple optional attribute types, separate them by spaces and dollar signs and enclose the entire set of optional attribute types in parentheses.

NOT

An optional list of attribute types that are prohibited from being present in entries with the associated structural class. This list cannot include any attribute types that are required by the structural class or any of the allowed auxiliary classes, but it can be used to prevent the inclusion of attribute types that would otherwise be allowed by one of those object classes. Values should be specified as one or more of the names or OIDs of the prohibited attribute types. If multiple types are prohibited , then separate them by spaces and dollar signs, and enclose the entire set of prohibited attribute types in parentheses.

extensions

An optional set of extensions for the DIT content rule. Oracle Unified Directory currently uses the following extensions for DIT content rules:

X-ORIGIN

Provides information about where the DIT content rule is defined (for example, whether it came from a particular RFC or Internet Draft, or whether it is defined within the project)

X-SCHEMA-FILE

Indicates which schema file contains the DIT content rule definition (This extension is generally used for internal purposes only and is exposed to clients.)

The following provides an example of a DIT content rule description:

( 2.16.840.1.113730.3.2.2 NAME 'inetOrgPersonContentRule'
AUX ( posixAccount $ shadowAccount $ authPasswordObject )
MUST uid )

In this case, the numeric OID is 2.16.840.1.113730.3.2.2, which is the OID for the inetOrgPerson structural object class. It has a human-readable name of inetOrgPersonContentRule and no description. It allows entries containing the inetOrgPerson object class to also contain the posixAccount, shadowAccount, and authPasswordObject auxiliary classes, and those entries must contain the uid attribute type. It is not marked OBSOLETE, and it does not define any additional optional or prohibited attribute types, nor does it include any extensions.

DIT Content Rule Implementation

At the present time, the mechanism used to handle DIT content rules varies from the LDAPv3 specification. The LDAPv3 specification states that if the structural object class used in an entry does not have a corresponding DIT content rule, then that entry is not allowed to contain any auxiliary object classes. Because Oracle Directory Server Enterprise Edition does not support DIT content rules, Oracle Unified Directory does not prevent the use of auxiliary object classes in entries for which there is no corresponding DIT content rule. If it is desirable to prevent the inclusion of auxiliary classes in a given type of entry, then a DIT content rule should be created with no allowed auxiliary classes to cover entries with the appropriate structural object class.