INTERNET-DRAFT Kurt D. Zeilenga Intended Category: Standard Track OpenLDAP Foundation Expires in six months 18 July 2004 The LDAP Assertion Control Status of this Memo This document is intended to be, after appropriate review and revision, submitted to the IESG for consideration as a Standard Track document. Distribution of this memo is unlimited. Technical discussion of this document will take place on the IETF LDAP Extensions mailing list . Please send editorial comments directly to the author . By submitting this Internet-Draft, I accept the provisions of Section 4 of RFC 3667. By submitting this Internet-Draft, I certify that any applicable patent or other IPR claims of which I am aware have been disclosed, or will be disclosed, and any of which I become aware will be disclosed, in accordance with RFC 3668. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at . The list of Internet-Draft Shadow Directories can be accessed at . Copyright (C) The Internet Society (2004). All Rights Reserved. Please see the Full Copyright section near the end of this document for more information. Abstract This document defines the Lightweight Directory Access Protocol (LDAP) Assertion Control which allows a client to specify that a directory Zeilenga LDAP Assertion Control [Page 1] INTERNET-DRAFT draft-zeilenga-ldap-assert-03 18 July 2004 operation should only be processed if an assertion applied to the target entry of the operation is true. It can be used to construct "test and set" and "test and clear" and other conditional operations. 1. Overview This document defines the Lightweight Directory Access Protocol (LDAP) [RFC3377] assertion control. The assertion control allows the client to specify a condition which must be true for the operation to be processed normally. Otherwise the operation fails. The control can be used with the Modify operation [RFC2251] to perform atomic "test and set" and "test and clear" operations as the asserted condition is evaluated as an integral part the operation. The control may be attached to other update operations to support conditional addition, deletion, and renaming of objects. The control may also be used with the search operation. Here the assertion is applied to the base object of the search before searching for objects matching the search scope and filter. The control may also be used with the compare operation. Here it extends the compare operation to allow a more complex assertion. 2. 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 [RFC2251]. DSA stands for Directory System Agent (or server). DSE stands for DSA-specific Entry. 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]. 3. The Assertion Control The assertion control is an LDAP Control [RFC2251] whose controlType is IANA-ASSIGNED-OID and controlValue is a BER-encoded Filter [RFC2251, Section 4.5.1]. The criticality may be TRUE or FALSE. There is no corresponding response control. Zeilenga LDAP Assertion Control [Page 2] INTERNET-DRAFT draft-zeilenga-ldap-assert-03 18 July 2004 The control is appropriate for both LDAP interrogation and update operations [RFC2251] including Add, Compare, Delete, Modify, ModifyDN (rename), and Search. It is inappropriate for Abandon, Bind nor Unbind operations. It is also inappropriate for the Start TLS [RFC2830] operation. When the control is attached to an LDAP request, the processing of the request is conditional on the evaluation of the Filter as applied against the target of the operation. If the Filter evaluates to TRUE, then the request is processed normally. If the Filter evaluates to FALSE or Undefined, then assertionFailed (IANA-ASSIGNED-CODE) resultCode is returned and no further processing is performed. For Add, Compare, and ModifyDN the target is indicated by the entry field in the request. For Modify, the target is indicated by the object field. For Delete, the target is indicated by the DelRequest type. For the Compare operation and all update operations, the evaluation of the assertion MUST be performed as an integral part of the operation. That is, the evaluation of the assertion and the normal processing of the operation SHALL be done as one atomic action. For search operation, the target is indicated by the baseObject field and the evaluation is done after "finding" but before "searching" [RFC2251]. Hence, no entries or continuations references are returned if the assertion fails. Servers implementing this technical specification SHOULD publish the object identifier IANA-ASSIGNED-OID as a value of the 'supportedControl' attribute [RFC2252] in their root DSE. A server MAY choose to advertise this extension only when the client is authorized to use it. Other documents may specify how this control applies to other LDAP operations. In doing so, they must state how the target entry is determined. 4. Security Considerations The filter may, like other components of the request, contain sensitive information. When so, this information should be appropriately protected. As with any general assertion mechanism, the mechanism can be used to determine directory content. Hence, this mechanism SHOULD be subject to appropriate access controls. Some assertions may be very complex, requiring significant time and Zeilenga LDAP Assertion Control [Page 3] INTERNET-DRAFT draft-zeilenga-ldap-assert-03 18 July 2004 resources to evaluate. Hence, this mechanism SHOULD be subject to appropriate administrative controls. All security considerations for the base operations [RFC2251] to which this control is attached to apply, as do general LDAP security considerations [RFC3377]. 5. IANA Considerations 5.1. Object Identifier It is requested that IANA assign upon Standards Action an LDAP Object Identifier [RFC3383] to identify the LDAP Assertion Control defined in this document. Subject: Request for LDAP Object Identifier Registration Person & email address to contact for further information: Kurt Zeilenga Specification: RFC XXXX Author/Change Controller: IESG Comments: Identifies the LDAP Assertion Control 5.2 LDAP Protocol Mechanism Registration of this protocol mechanism [RFC3383] is requested. Subject: Request for LDAP Protocol Mechanism Registration Object Identifier: IANA-ASSIGNED-OID Description: Assertion Control Person & email address to contact for further information: Kurt Zeilenga Usage: Control Specification: RFC XXXX Author/Change Controller: IESG Comments: none 5.3 LDAP Result Code Assignment of an LDAP Result Code [RFC3383] called 'assertionFailed' is requested. Subject: LDAP Result Code Registration Person & email address to contact for further information: Kurt Zeilenga Result Code Name: assertionFailed Zeilenga LDAP Assertion Control [Page 4] INTERNET-DRAFT draft-zeilenga-ldap-assert-03 18 July 2004 Specification: RFC XXXX Author/Change Controller: IESG Comments: none 6. Acknowledgments The assertion control concept is attributed to Morteza Ansari. 7. Author's Address Kurt D. Zeilenga OpenLDAP Foundation Email: Kurt@OpenLDAP.org 8. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14 (also RFC 2119), March 1997. [RFC2251] Wahl, M., T. Howes and S. Kille, "Lightweight Directory Access Protocol (v3)", RFC 2251, December 1997. [RFC2252] Wahl, M., A. Coulbeck, T. Howes, and S. Kille, "Lightweight Directory Access Protocol (v3): Attribute Syntax Definitions", RFC 2252, December 1997. [RFC3377] Hodges, J. and R. Morgan, "Lightweight Directory Access Protocol (v3): Technical Specification", RFC 3377, September 2002. 9. Informative References [RFC3383] Zeilenga, K., "IANA Considerations for LDAP", BCP 64 (also RFC 3383), September 2002. Intellectual Property Rights 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 Zeilenga LDAP Assertion Control [Page 5] INTERNET-DRAFT draft-zeilenga-ldap-assert-03 18 July 2004 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 Copyright (C) The Internet Society (2004). 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 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 Assertion Control [Page 6]