INTERNET-DRAFT Kurt D. Zeilenga Intended Category: Experimental Isode Limited Expires in six months 14 February 2007 The LDAP Relax Rules Control <draft-zeilenga-ldap-relax-01.txt> Status of this Memo This document is intended to be, after appropriate review and revision, submitted to the RFC Editor for publication as an Experimental document. Distribution of this memo is unlimited. Technical discussion of this document will take place on the IETF LDAP Extensions mailing list <ldapext@ietf.org>. Please send editorial comments directly to the author <Kurt.Zeilenga@Isode.COM>. This document replaces draft-zeilenga-ldap-managedit-xx.txt. By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. 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Zeilenga LDAP Relax Rules Control [Page 1]  INTERNET-DRAFT draft-zeilenga-ldap-relax-01 14 February 2007 Abstract This document defines the Lightweight Directory Access Protocol (LDAP) Relax Rules Control which allows a directory user agent (a client) to request the directory service temporarily relax enforcement of various data and service model rules. 1. Background and Intended Use Directory servers accessible via Lightweight Directory Access Protocol (LDAP) [RFC4510] are expected to act in accordance with the X.500 [X.500] series of ITU-T Recommendations. In particular, servers are expected to ensure the X.500 data and service models are not violated. An LDAP server is expected to prevent modification of the structural object class of an object [RFC4512]. That is, the X.500 models do not allow a 'person' object to be transformed into an 'organizationalPerson' object through modification of the object. Instead, the 'person' object must be deleted and then a new 'organizationalPerson' object created in its place. This approach, aside from being inconvient, is problematic for a number reasons. First, as LDAP does not have a standardized method for performing the two operations in a single transaction, the intermediate directory state (after the delete, before the add) is visible to other clients, which may lead to undesirable client behavior. Second, attributes such as 'entryUUID' [RFC4530] will reflect the object was replaced, not transformed. An LDAP server is expected to prevent clients from modifying values of NO-USER-MODIFICATION attributes [RFC4512]. For instance, an entry is not allowed to assign or modify the value of the 'entryUUID' attribute. However, where an administrator is restoring a previously existing object, for instance when repartitioning data between directory servers or when migrating from one vendor server product to another, it may be desirable to allow the client to assign or modify the value of the 'entryUUID' attribute. This document defines the LDAP Relax Rules control. This control may be attached to LDAP requests to update the Directory Information Tree (DIT) to request various data and service rules be temporarily relaxed during the performance of the requested DIT update. The server is however to ensure the resulting directory state is valid. Use of this control is expected that use of this extension will be restricted by administrative and/or access controls. It is intended to be used primarily by directory administrators. Zeilenga LDAP Relax Rules Control [Page 2]  INTERNET-DRAFT draft-zeilenga-ldap-relax-01 14 February 2007 This extension is considered experimental as it is not yet clear whether it adequately addresses directory administrators' needs for flexible mechanisms for managing directory objects. It is hoped that after suitable amount of time, either this extension or a suitable replacement will be standardization. 1.1. Terminology Protocol elements are described using ASN.1 [X.680] with implicit tags. The term "BER-encoded" means the element is to be encoded using the Basic Encoding Rules [X.690] under the restrictions detailed in Section 5.1 of [RFC4511]. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119]. DSA stands for Directory System Agent, a server. DSE stands for DSA-specific Entry. 2. The Relax Rules Control The Relax Rules control is an LDAP Control [RFC4511] whose controlType is IANA-ASSIGNED-OID, controlValue is empty, and the criticality of TRUE. There is no corresponding response control. The control is appropriate for all LDAP update requests, including add, delete, modify, and modifyDN (rename) [RFC4511]. The presence of the Rules Rules control in an LDAP update request indicates the server temporarily relax X.500 model contraints during performance of the directory update. The server may restrict use of this control and/or limit the extent of the relaxation provided based upon local policy or factors. The server is obligated to ensure the resulting directory state is consistent with the X.500 models. For instance, the server ensure that values of attributes conform to the value syntax. It is noted that while this extension may be used to add or modify objects in a manner which violate the controlling subschema, the presence of objects in the DIT is not inconsistent with the X.500 models. For instance, an object created prior to establshment of a Zeilenga LDAP Relax Rules Control [Page 3]  INTERNET-DRAFT draft-zeilenga-ldap-relax-01 14 February 2007 DIT content rule may contain an attribute now precluded by the current controlling DIT Content Rule. Servers implementing this technical specification SHOULD publish the object identifier IANA-ASSIGNED-OID as a value of the 'supportedControl' attribute [RFC4512] in their root DSE. A server MAY choose to advertise this extension only when the client is authorized to use it. 3. Use Cases 3.1. Object metamorphism In absence of this control, an attempt to modify an object's 'objectClass' in a manner which cause a change in the structural object class of the object would normally lead to an objectClassModsProhibited error [RFC4511]. The presence of the Relax Rules control in the modify request requests the change be allowed. If the server is willing and able to allow the change in the structural object class of the object. For instance, to change an 'organization' object into an 'organizationalUnit' object, a client could issue the following LDAP request: dn: o=Unit,dc=example,dc=net control: IANA-ASSIGNED-OID changetype: modify delete: objectClass objectClass: organization - add: objectClass objectClass: organizationalUnit - In this case, the server is expected to either effect the requested change in the structural object class, including updating of the value of the structural object class, or fail the operation. 3.2. Inactive Attribute Types In absence of the Relax Rules control, an attempt to add or modify values to an attribute whose type has been marked inactive in the controlling subschema (its attribute type description contains the OBSOLETE field) [RFC4512] normally results in a failure. Zeilenga LDAP Relax Rules Control [Page 4]  INTERNET-DRAFT draft-zeilenga-ldap-relax-01 14 February 2007 In the presence of the Relax Rules control, the server performs the update operation as if the attribute's type is marked active in the controlling subschema (its attribute type description does not contain the OBSOLETE field). 3.3. DIT Content Rules In absence of the Relax Rules control, an attempt to include the name (or OID) of an auxiliary class to an object's 'objectClass' which is not allowed by the controlling DIT Content Rule would be disallowed [RFC4512]. Additionally, an attempt to add values of an attribute not allowed (or explicitly precluded) by the DIT Content Rule would fail. In presence of the Relax Rules control, the server performs the update operation as if the controlling DIT Content Rule allowed any and all known auxiliary classses to be present and allowed any and all known attributes to be present (and precluded no attributes). 3.4. DIT Structure Rules and Name Forms In absence of the Relax Rules control, the service enforces DIT structure rules and name form requirements of the controlling subschema [RFC4512]. In the presence of the Relax Rules control, the server performs the update operation ignoring all DIT structure rules and name forms in the controlling subschema. 3.5. Modification of Nonconformant Objects It is also noted that in absense of this control, modification of an object which presently violates the controlling subschema will fail unless the modification would result in the object conforming to the controlling subschema. That is, modifications of an non-conformant object should result in a conformant object. In the presence of this control, modifications of a non-conformant object need not result in a conformant object. 3.6. NO-USER-MODIFICATION attribute modification In absence of this control, an attempt to modify values of a NO-USER-MODIFICATION attribute [RFC4512] would normally lead to a Zeilenga LDAP Relax Rules Control [Page 5]  INTERNET-DRAFT draft-zeilenga-ldap-relax-01 14 February 2007 constraintViolation or other appropriate error [RFC4511]. In the presence of the Relax Rules control in the update request requests the modification be allowed. Relaxation of the NO-USER-MODIFICATION constraint is not appropriate for some operational attribute types. For instance, as the value of the 'structuralObjectClass' is derived by the values of the 'objectClass' attribute, the 'structuralObjectClass' attribute type's NO-USER-MODIFICATION contraint MUST NOT be relaxed. To effect a change in the structuralObjectClass class, values of objectClass should be changed as discussed in Section 3.1. Other attributes for which the NO-USER-MODIFICATION constraint should not be relaxed include 'subschemaSubentry' [RFC4512] and 'collectiveAttributeSubentries' [RFC3671]. The subsections of this section discuss modification of various operational attributes where their NO-USER-MODIFICATION constraint may be relaxed. Future documents may specify where NO-USER-MODIFICATION constraints on other operational attribute may be relaxed. In absence of a document detailing that the NO-USER-MODIFICATION constraint on a particular operational attribute may be relaxed, implementors SHOULD assume relaxation of the constraint is not appropriate for that attribute. 3.1.1. 'entryUUID' attribute To provide a value for the 'entryUUID' [RFC4530] attribute on entry creation, the client should issue an LDAP Add request with a Relax Rules control providing the desired value. For instance: dn: ou=Unit,dc=example,dc=net control: IANA-ASSIGNED-OID changetype: add objectClass: organizationalUnit ou: Unit entryUUID: 597ae2f6-16a6-1027-98f4-d28b5365dc14 In this case, the server is either to add the entry using the provided 'entryUUID' value or fail the request. To provide a replacement value for the 'entryUUID' after entry creation, the client should issue an LDAP Modify request with a Relax Rules control including an approrpiate change. For instance: dn: ou=Unit,dc=example,dc=net control: IANA-ASSIGNED-OID changetype: modify Zeilenga LDAP Relax Rules Control [Page 6]  INTERNET-DRAFT draft-zeilenga-ldap-relax-01 14 February 2007 replace: entryUUID entryUUID: 597ae2f6-16a6-1027-98f4-d28b5365dc14 - In this case, the server is either to replace the 'entryUUID' value as requested or fail the request. 3.2.2. createTimestamp To provide a value for the 'createTimestamp' [RFC4512] attribute on entry creation, the client should issue an LDAP Add request with a Relax Rules control providing the desired 'createTimestamp' value. For instance: dn: ou=Unit,dc=example,dc=net control: IANA-ASSIGNED-OID changetype: add objectClass: organizationalUnit ou: Unit createTimestamp: 20060101000000Z In this case, the server is either to add the entry using the provided 'createTimestamp' value or fail the request. To provide a replacement value for the 'createTimestamp' after entry creation, the client should issue an LDAP Modify request with a Relax Rules control including an approrpiate change. For instance: dn: ou=Unit,dc=example,dc=net control: IANA-ASSIGNED-OID changetype: modify replace: createTimestamp createTimestamp: 20060101000000Z - In this case, the server is either to replace the 'createTimestamp' value as requested or fail the request. The server should ensure the requested 'createTimestamp' value is appropriate. In particular, it should fail the request if the requested 'createTimestamp' value is in the future or is greater than the value of the 'modifyTimestamp' attribute. 3.2.3. modifyTimestamp To provide a value for the 'modifyTimestamp' [RFC4512] attribute Zeilenga LDAP Relax Rules Control [Page 7]  INTERNET-DRAFT draft-zeilenga-ldap-relax-01 14 February 2007 on entry creation, the client should issue an LDAP Add request with a Relax Rules control providing the desired 'modifyTimestamp' value. For instance: dn: ou=Unit,dc=example,dc=net control: IANA-ASSIGNED-OID changetype: add objectClass: organizationalUnit ou: Unit modifyTimestamp: 20060101000000Z In this case, the server is either to add the entry using the provided 'modifyTimestamp' value or fail the request. To provide a replacement value for the 'modifyTimestamp' after entry creation, the client should issue an LDAP Modify request with a Relax Rules control including an approrpiate change. For instance: dn: ou=Unit,dc=example,dc=net control: IANA-ASSIGNED-OID changetype: modify replace: modifyTimestamp modifyTimestamp: 20060101000000Z - In this case, the server is either to replace the 'modifyTimestamp' value as requested or fail the request. The server should ensure the requested 'modifyTimestamp' value is appropriate. In particular, it should fail the request if the requested 'modifyTimestamp' value is in the future or is less than the value of the 'createTimestamp' attribute. 3.2.3. creatorsName and modifiersName To provide a value for the 'creatorsName' and/or 'modifiersName' [RFC4512] attribute on entry creation, the client should issue an LDAP Add request with a Relax Rules control providing the desired values. For instance: dn: ou=Unit,dc=example,dc=net control: IANA-ASSIGNED-OID changetype: add objectClass: organizationalUnit ou: Unit creatorsName: cn=Jane Doe,dc=example,net Zeilenga LDAP Relax Rules Control [Page 8]  INTERNET-DRAFT draft-zeilenga-ldap-relax-01 14 February 2007 modifiersName: cn=Jane Doe,dc=example,net In this case, the server is either to add the entry using the provided values or fail the request. To provide a replacement values after entry creation for either of the 'creatorsName' or 'modifiersName' attributes or both, the client should issue an LDAP Modify request with a Relax Rules control including the approrpiate changes. For instance: dn: ou=Unit,dc=example,dc=net control: IANA-ASSIGNED-OID changetype: modify replace: creatorsName creatorsName: cn=Jane Doe,dc=example,net - replace: modifiersName modifiersName: cn=Jane Doe,dc=example,net - In this case, the server is either to replace the provided values as requested or fail the request. 4. Security Considerations Use of this extension should be subject to appropriate administrative and access controls. Use of this mechanism is intended to be restricted to directory administrators. Security considerations for the base operations [RFC4511] extended by this control, as well as general LDAP security considerations [RFC4510], generally apply to implementation and use of this extension. 5. IANA Considerations 5.1. Object Identifier It is requested that the IANA assign a LDAP Object Identifier [RFC4520] to identify the LDAP Relax Rules Control defined in this document. Subject: Request for LDAP Object Identifier Registration Person & email address to contact for further information: Kurt Zeilenga <Kurt.Zeilenga@Isode.COM> Specification: RFC XXXX Zeilenga LDAP Relax Rules Control [Page 9]  INTERNET-DRAFT draft-zeilenga-ldap-relax-01 14 February 2007 Author/Change Controller: Kurt Zeilenga <Kurt.Zeilenga@Isode.COM> Comments: Identifies the LDAP Relax Rules Control 5.2 LDAP Protocol Mechanism Registration of this protocol mechanism [RFC4520] is requested. Subject: Request for LDAP Protocol Mechanism Registration Object Identifier: IANA-ASSIGNED-OID Description: Relax Rules Control Person & email address to contact for further information: Kurt Zeilenga <Kurt.Zeilenga@Isode.COM> Usage: Control Specification: RFC XXXX Author/Change Controller: Kurt Zeilenga <Kurt.Zeilenga@Isode.COM> Comments: none 6. Author's Address Kurt D. Zeilenga Isode Limited Email: Kurt.Zeilenga@Isode.COM 7. References [[Note to the RFC Editor: please replace the citation tags used in referencing Internet-Drafts with tags of the form RFCnnnn where possible.]] 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14 (also RFC 2119), March 1997. [RFC3671] Zeilenga, K., "Collective Attributes in LDAP", RFC 3671, December 2003. [RFC4510] Zeilenga, K. (editor), "LDAP: Technical Specification Road Map", RFC 4510, June 2006. [RFC4511] Sermersheim, J. (editor), "LDAP: The Protocol", RFC 4511, June 2006. [RFC4512] Zeilenga, K. (editor), "LDAP: Directory Information Zeilenga LDAP Relax Rules Control [Page 10]  INTERNET-DRAFT draft-zeilenga-ldap-relax-01 14 February 2007 Models", RFC 4512, June 2006. [RFC4530] Zeilenga, K., "Lightweight Directory Access Protocol (LDAP) entryUUID Operational Attribute", RFC 4530, June 2006. [X.500] International Telecommunication Union - Telecommunication Standardization Sector, "The Directory -- Overview of concepts, models and services," X.500(1993) (also ISO/IEC 9594-1:1994). 7.2. Informative References [RFC4520] Zeilenga, K., "Internet Assigned Numbers Authority (IANA) Considerations for the Lightweight Directory Access Protocol (LDAP)", RFC 4520, BCP 64, June 2006. Intellectual Property The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Full Copyright Zeilenga LDAP Relax Rules Control [Page 11]  INTERNET-DRAFT draft-zeilenga-ldap-relax-01 14 February 2007 Copyright (C) The IETF Trust (2007). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Zeilenga LDAP Relax Rules Control [Page 12]