--- 1/draft-ietf-ldapbis-protocol-17.txt 2006-02-05 00:12:10.000000000 +0100 +++ 2/draft-ietf-ldapbis-protocol-18.txt 2006-02-05 00:12:10.000000000 +0100 @@ -1,14 +1,14 @@ Internet-Draft Editor: J. Sermersheim Intended Category: Standard Track Novell, Inc -Document: draft-ietf-ldapbis-protocol-17.txt Sep 2003 +Document: draft-ietf-ldapbis-protocol-18.txt Oct 2003 Obsoletes: RFC 2251 LDAP: The Protocol Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering @@ -26,130 +26,133 @@ http://www.ietf.org/shadow.html. Distribution of this memo is unlimited. Technical discussion of this document will take place on the IETF LDAP Revision Working Group (LDAPbis) mailing list . Please send editorial comments directly to the editor . Abstract This document describes the protocol elements, along with their - semantics and encodings, for the Lightweight Directory Access - Protocol (LDAP). LDAP provides access to distributed directory - services that act in accordance with X.500 data and service models. - These protocol elements are based on those described in the X.500 - Directory Access Protocol (DAP). + semantics and encodings, of the Lightweight Directory Access Protocol + (LDAP). LDAP provides access to distributed directory services that + act in accordance with X.500 data and service models. These protocol + elements are based on those described in the X.500 Directory Access + Protocol (DAP). Table of Contents 1. Introduction....................................................3 2. Conventions.....................................................3 3. Protocol Model..................................................3 4. Elements of Protocol............................................4 4.1. Common Elements...............................................4 4.1.1. Message Envelope............................................4 4.1.2. String Types................................................6 4.1.3. Distinguished Name and Relative Distinguished Name..........6 -Sermersheim Internet-Draft - Expires Mar 2004 Page 1 +Sermersheim Internet-Draft - Expires Apr 2004 Page 1 Lightweight Directory Access Protocol Version 3 4.1.4. Attribute Descriptions......................................7 4.1.5. Attribute Value.............................................7 4.1.6. Attribute Value Assertion...................................7 4.1.7. Attribute...................................................8 4.1.8. Matching Rule Identifier....................................8 4.1.9. Result Message..............................................8 4.1.10. Referral..................................................10 4.1.11. Controls..................................................11 4.2. Bind Operation...............................................12 4.3. Unbind Operation.............................................15 4.4. Unsolicited Notification.....................................15 4.5. Search Operation.............................................16 4.6. Modify Operation.............................................24 - 4.7. Add Operation................................................25 + 4.7. Add Operation................................................26 4.8. Delete Operation.............................................26 4.9. Modify DN Operation..........................................27 4.10. Compare Operation...........................................28 4.11. Abandon Operation...........................................29 - 4.12. Extended Operation..........................................30 + 4.12. Extended Operation..........................................29 4.13. Start TLS Operation.........................................31 5. Protocol Element Encodings and Transfer........................33 5.1. Protocol Encoding............................................33 5.2. Transfer Protocols...........................................33 6. Implementation Guidelines......................................33 - 6.1. Server Implementations.......................................34 + 6.1. Server Implementations.......................................33 6.2. Client Implementations.......................................34 7. Security Considerations........................................34 8. Acknowledgements...............................................35 9. Normative References...........................................35 10. Informative References........................................37 11. IANA Considerations...........................................37 12. Editor's Address..............................................37 Appendix A - LDAP Result Codes....................................38 A.1 Non-Error Result Codes........................................38 A.2 Result Codes..................................................38 - Appendix C - Change History.......................................49 - C.1 Changes made to RFC 2251:.....................................49 - C.2 Changes made to draft-ietf-ldapbis-protocol-00.txt:...........49 - C.3 Changes made to draft-ietf-ldapbis-protocol-01.txt:...........50 - C.4 Changes made to draft-ietf-ldapbis-protocol-02.txt:...........50 - C.5 Changes made to draft-ietf-ldapbis-protocol-03.txt:...........52 - C.6 Changes made to draft-ietf-ldapbis-protocol-04.txt:...........54 - C.7 Changes made to draft-ietf-ldapbis-protocol-05.txt:...........54 - C.8 Changes made to draft-ietf-ldapbis-protocol-06.txt:...........55 - C.9 Changes made to draft-ietf-ldapbis-protocol-07.txt:...........58 - C.10 Changes made to draft-ietf-ldapbis-protocol-08.txt:..........58 - C.11 Changes made to draft-ietf-ldapbis-protocol-09.txt:..........58 - C.12 Changes made to draft-ietf-ldapbis-protocol-10.txt:..........58 - C.13 Changes made to draft-ietf-ldapbis-protocol-11.txt:..........59 - C.14 Changes made to draft-ietf-ldapbis-protocol-12.txt:..........59 - C.15 Changes made to draft-ietf-ldapbis-protocol-13.txt...........59 - C.16 Changes made to draft-ietf-ldapbis-protocol-14.txt...........60 - C.17 Changes made to draft-ietf-ldapbis-protocol-15.txt...........62 - C.18 Changes made to draft-ietf-ldapbis-protocol-16.txt...........62 + Appendix C - Change History.......................................47 + C.1 Changes made to RFC 2251:.....................................47 + C.2 Changes made to draft-ietf-ldapbis-protocol-00.txt:...........47 + C.3 Changes made to draft-ietf-ldapbis-protocol-01.txt:...........48 + C.4 Changes made to draft-ietf-ldapbis-protocol-02.txt:...........48 + C.5 Changes made to draft-ietf-ldapbis-protocol-03.txt:...........50 + C.6 Changes made to draft-ietf-ldapbis-protocol-04.txt:...........52 + C.7 Changes made to draft-ietf-ldapbis-protocol-05.txt:...........52 + C.8 Changes made to draft-ietf-ldapbis-protocol-06.txt:...........53 + C.9 Changes made to draft-ietf-ldapbis-protocol-07.txt:...........56 + C.10 Changes made to draft-ietf-ldapbis-protocol-08.txt:..........56 + C.11 Changes made to draft-ietf-ldapbis-protocol-09.txt:..........56 + C.12 Changes made to draft-ietf-ldapbis-protocol-10.txt:..........56 + C.13 Changes made to draft-ietf-ldapbis-protocol-11.txt:..........57 + C.14 Changes made to draft-ietf-ldapbis-protocol-12.txt:..........57 + C.15 Changes made to draft-ietf-ldapbis-protocol-13.txt...........57 + C.16 Changes made to draft-ietf-ldapbis-protocol-14.txt...........58 + C.17 Changes made to draft-ietf-ldapbis-protocol-15.txt...........60 + C.18 Changes made to draft-ietf-ldapbis-protocol-16.txt...........60 -Sermersheim Internet-Draft - Expires Mar 2004 Page 2 +Sermersheim Internet-Draft - Expires Apr 2004 Page 2 Lightweight Directory Access Protocol Version 3 - Appendix D - Outstanding Work Items...............................63 + C.19 Changes made to draft-ietf-ldapbis-protocol-17.txt...........61 1. Introduction The Directory is "a collection of open systems cooperating to provide - directory services" [X.500]. A Directory user, which may be a human + directory services" [X.500]. A directory user, which may be a human or other entity, accesses the Directory through a client (or Directory User Agent (DUA)). The client, on behalf of the directory user, interacts with one or more servers (or Directory System Agents (DSA)). Clients interact with servers using a directory access protocol. - This document details the protocol elements of Lightweight Directory - Access Protocol, along with their semantics. Following the - description of protocol elements, it describes the way in which the - protocol is encoded and transferred. + This document details the protocol elements of the Lightweight + Directory Access Protocol (LDAP), along with their semantics. + Following the description of protocol elements, it describes the way + in which the protocol elements are encoded and transferred. This document is an integral part of the LDAP Technical Specification [Roadmap]. This document replaces RFC 2251. Appendix C holds a detailed log of - changes to RFC 2251. Prior to Working Group Last Call, this appendix + changes to RFC 2251. After Working Group Last Call, this appendix will be distilled to a summary of changes to RFC 2251. 2. Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", and "MAY" in this document are - to be interpreted as described in [RFC2119]. + to be interpreted as described in [Keyword]. + The terms "connection" and "LDAP connection" both refer to the underlying transport protocol connection between two protocol peers. + The term "TLS connection" refers to a TLS-protected LDAP connection. + The terms "association" and "LDAP association" both refer to the association of the LDAP connection and its current authentication and authorization state. 3. Protocol Model The general model adopted by this protocol is one of clients performing protocol operations against servers. In this model, a client transmits a protocol request describing the operation to be performed to a server. The server is then responsible for performing @@ -146,87 +149,86 @@ The terms "association" and "LDAP association" both refer to the association of the LDAP connection and its current authentication and authorization state. 3. Protocol Model The general model adopted by this protocol is one of clients performing protocol operations against servers. In this model, a client transmits a protocol request describing the operation to be performed to a server. The server is then responsible for performing - the necessary operation(s) in the directory. Upon completion of the + the necessary operation(s) in the Directory. Upon completion of the operation(s), the server returns a response containing an appropriate result code to the requesting client. +Sermersheim Internet-Draft - Expires Apr 2004 Page 3 + Lightweight Directory Access Protocol Version 3 + Although servers are required to return responses whenever such responses are defined in the protocol, there is no requirement for synchronous behavior on the part of either clients or servers. Requests and responses for multiple operations may be exchanged - -Sermersheim Internet-Draft - Expires Mar 2004 Page 3 - Lightweight Directory Access Protocol Version 3 - between a client and server in any order, provided the client eventually receives a response for every request that requires one. The core protocol operations defined in this document can be mapped - to a subset of the X.500 (1997) directory abstract service. However + to a subset of the X.500 (1993) Directory Abstract Service. However there is not a one-to-one mapping between LDAP protocol operations - and DAP operations. Server implementations acting as a gateway to - X.500 directories may need to make multiple DAP requests. + and X.500 Directory Access Protocol (DAP) operations. Server + implementations acting as a gateway to X.500 directories may need to + make multiple DAP requests to service a single LDAP request. 4. Elements of Protocol - The LDAP protocol is described using Abstract Syntax Notation 1 - (ASN.1) [X.680], and is transferred using a subset of ASN.1 Basic - Encoding Rules [X.690]. Section 5.1 specifies how the protocol is + The LDAP protocol is described using Abstract Syntax Notation One + [ASN.1], and is transferred using a subset of ASN.1 Basic Encoding + Rules [BER]. Section 5.1 specifies how the protocol elements are encoded and transferred. In order to support future Standards Track extensions to this protocol, extensibility is implied where it is allowed (per ASN.1). In addition, ellipses (...) have been supplied in ASN.1 types that are explicitly extensible as discussed in [LDAPIANA]. Because of the implied extensibility, clients and servers MUST (unless otherwise - specified) ignore trailing SEQUENCE elements whose tags they do not + specified) ignore trailing SEQUENCE components whose tags they do not recognize. Changes to the LDAP protocol other than through the extension mechanisms described here require a different version number. A client indicates the version it is using as part of the bind request, described in section 4.2. If a client has not sent a bind, the server MUST assume the client is using version 3 or later. Clients may determine the protocol versions a server supports by - reading the supportedLDAPVersion attribute from the root DSE - [Models]. Servers which implement version 3 or later MUST provide - this attribute. + reading the supportedLDAPVersion attribute from the root DSE (DSA- + Specific Entry) [Models]. Servers which implement version 3 or later + MUST provide this attribute. 4.1. Common Elements This section describes the LDAPMessage envelope PDU (Protocol Data Unit) format, as well as data type definitions, which are used in the protocol operations. 4.1.1. Message Envelope For the purposes of protocol exchanges, all protocol operations are encapsulated in a common envelope, the LDAPMessage, which is defined as follows: +Sermersheim Internet-Draft - Expires Apr 2004 Page 4 + Lightweight Directory Access Protocol Version 3 + LDAPMessage ::= SEQUENCE { messageID MessageID, protocolOp CHOICE { bindRequest BindRequest, - -Sermersheim Internet-Draft - Expires Mar 2004 Page 4 - Lightweight Directory Access Protocol Version 3 - bindResponse BindResponse, unbindRequest UnbindRequest, searchRequest SearchRequest, searchResEntry SearchResultEntry, searchResDone SearchResultDone, searchResRef SearchResultReference, modifyRequest ModifyRequest, modifyResponse ModifyResponse, addRequest AddRequest, addResponse AddResponse, @@ -247,176 +249,174 @@ maxInt INTEGER ::= 2147483647 -- (2^^31 - 1) -- The function of the LDAPMessage is to provide an envelope containing common fields required in all protocol exchanges. At this time the only common fields are the message ID and the controls. If the server receives a PDU from the client in which the LDAPMessage SEQUENCE tag cannot be recognized, the messageID cannot be parsed, the tag of the protocolOp is not recognized as a request, or the encoding structures or lengths of data fields are found to be - incorrect, then the server MAY return the Notice of Disconnection + incorrect, then the server SHOULD return the Notice of Disconnection described in section 4.4.1, with the resultCode set to protocolError, and MUST immediately close the connection. In other cases where the client or server cannot parse a PDU, it SHOULD abruptly close the connection where further communication (including providing notice) would be pernicious. Otherwise, server implementations MUST return an appropriate response to the request, with the resultCode set to protocolError. The ASN.1 type Controls is defined in section 4.1.11. 4.1.1.1. Message ID +Sermersheim Internet-Draft - Expires Apr 2004 Page 5 + Lightweight Directory Access Protocol Version 3 + All LDAPMessage envelopes encapsulating responses contain the messageID value of the corresponding request LDAPMessage. The message ID of a request MUST have a non-zero value different from the values of any other requests outstanding in the LDAP association - -Sermersheim Internet-Draft - Expires Mar 2004 Page 5 - Lightweight Directory Access Protocol Version 3 - of which this message is a part. The zero value is reserved for the unsolicited notification message. Typical clients increment a counter for each request. A client MUST NOT send a request with the same message ID as an earlier request on the same LDAP association unless it can be determined that the server is no longer servicing the earlier request. Otherwise the behavior is undefined. For operations that do not return responses (unbind, abandon, and abandoned operations), the client SHOULD assume the operation is in progress until a subsequent bind request completes. 4.1.2. String Types The LDAPString is a notational convenience to indicate that, although strings of LDAPString type encode as OCTET STRING types, the [ISO10646] character set (a superset of [Unicode]) is used, encoded - following the UTF-8 algorithm [RFC2279]. Note that in the UTF-8 - algorithm characters which are the same as ASCII (0x0000 through - 0x007F) are represented as that same ASCII character in a single - byte. The other byte values are used to form a variable-length - encoding of an arbitrary character. + following the [UTF-8] algorithm. Note that Unicode characters U+0000 + through U+007F are the same as ASCII 0 through 127, respectively, and + have the same single octet UTF-8 encoding. Other Unicode characters + have a multiple octet UTF-8 encoding. LDAPString ::= OCTET STRING -- UTF-8 encoded, - -- ISO 10646 characters + -- [ISO10646] characters The LDAPOID is a notational convenience to indicate that the permitted value of this string is a (UTF-8 encoded) dotted-decimal representation of an OBJECT IDENTIFIER. Although an LDAPOID is encoded as an OCTET STRING, values are limited to the definition of - numericoid given in Section 1.3 of [Models]. + given in Section 1.3 of [Models]. - LDAPOID ::= OCTET STRING -- Constrained to numericoid [Models] + LDAPOID ::= OCTET STRING -- Constrained to [Models] For example, 1.3.6.1.4.1.1466.1.2.3 4.1.3. Distinguished Name and Relative Distinguished Name - An LDAPDN and a RelativeLDAPDN are respectively defined to be the - representation of a distinguished-name and a relative-distinguished- - name after encoding according to the specification in [LDAPDN]. + An LDAPDN is defined to be the representation of a distinguished name + (DN) after encoding according to the specification in [LDAPDN]. LDAPDN ::= LDAPString - -- Constrained to distinguishedName [LDAPDN] - - RelativeLDAPDN ::= LDAPString - -- Constrained to name-component [LDAPDN] + -- Constrained to [LDAPDN] -Sermersheim Internet-Draft - Expires Mar 2004 Page 6 +Sermersheim Internet-Draft - Expires Apr 2004 Page 6 Lightweight Directory Access Protocol Version 3 + A RelativeLDAPDN is defined to be the representation of a relative + distinguished name (RDN) after encoding according to the + specification in [LDAPDN]. + + RelativeLDAPDN ::= LDAPString + -- Constrained to [LDAPDN] + 4.1.4. Attribute Descriptions The definition and encoding rules for attribute descriptions are defined in Section 2.5 of [Models]. Briefly, an attribute description is an attribute type and zero or more options. AttributeDescription ::= LDAPString - -- Constrained to attributedescription + -- Constrained to -- [Models] 4.1.5. Attribute Value A field of type AttributeValue is an OCTET STRING containing an - encoded attribute value data type. The value is encoded according to - its LDAP-specific encoding definition. The LDAP-specific encoding - definitions for different syntaxes and attribute types may be found - in other documents and in particular [Syntaxes]. + encoded attribute value. The attribute value is encoded according to + the LDAP-specific encoding definition of its corresponding syntax. + The LDAP-specific encoding definitions for different syntaxes and + attribute types may be found in other documents and in particular + [Syntaxes]. AttributeValue ::= OCTET STRING Note that there is no defined limit on the size of this encoding; thus protocol values may include multi-megabyte attributes (e.g. photographs). Attributes may be defined which have arbitrary and non-printable - syntax. Implementations MUST NOT display nor attempt to decode as - ASN.1, a value if its syntax is not known. The implementation may - attempt to discover the subschema of the source entry, and retrieve - the values of attributeTypes from it. + syntax. Implementations MUST NOT display nor attempt to decode a + value if its syntax is not known. The implementation may attempt to + discover the subschema of the source entry, and retrieve the + descriptions of attributeTypes from it [Models]. Clients MUST NOT send attribute values in a request that are not valid according to the syntax defined for the attributes. 4.1.6. Attribute Value Assertion The AttributeValueAssertion type definition is similar to the one in - the X.500 directory standards. It contains an attribute description + the X.500 Directory standards. It contains an attribute description and a matching rule assertion value suitable for that type. AttributeValueAssertion ::= SEQUENCE { attributeDesc AttributeDescription, assertionValue AssertionValue } +Sermersheim Internet-Draft - Expires Apr 2004 Page 7 + Lightweight Directory Access Protocol Version 3 + AssertionValue ::= OCTET STRING The syntax of the AssertionValue depends on the context of the LDAP operation being performed. For example, the syntax of the EQUALITY matching rule for an attribute is used when performing a Compare operation. Often this is the same syntax used for values of the attribute type, but in some cases the assertion syntax differs from the value syntax. See objectIdentiferFirstComponentMatch in [Syntaxes] for an example. -Sermersheim Internet-Draft - Expires Mar 2004 Page 7 - Lightweight Directory Access Protocol Version 3 - 4.1.7. Attribute An attribute consists of an attribute description and one or more - values of that attribute description. (Though attributes MUST have at - least one value when stored, due to access control restrictions the - set may be empty when transferred from the server to the client. This - is described in section 4.5.2, concerning the PartialAttributeList - type.) + values of that attribute description. Attribute ::= SEQUENCE { type AttributeDescription, - vals SET OF AttributeValue } + vals SET SIZE (1..MAX) OF value AttributeValue } Each attribute value is distinct in the set (no duplicates). The set - of attribute values is unordered. Implementations MUST NOT reply upon - any apparent ordering being repeatable. + of attribute values is unordered. Implementations MUST NOT rely upon + the ordering being repeatable. 4.1.8. Matching Rule Identifier Matching rules are defined in 4.1.3 of [Models]. A matching rule is identified in the LDAP protocol by the printable representation of - either its numericoid, or one of its short name descriptors, e.g. - "caseIgnoreIA5Match" or "1.3.6.1.4.1.453.33.33". + either its , or one of its short name descriptors + [Models], e.g. "caseIgnoreIA5Match" or "1.3.6.1.4.1.453.33.33". MatchingRuleId ::= LDAPString 4.1.9. Result Message The LDAPResult is the construct used in this protocol to return success or failure indications from servers to clients. To various requests, servers will return responses of LDAPResult or responses containing the components of LDAPResult to indicate the final status of a protocol operation request. @@ -426,28 +426,28 @@ success (0), operationsError (1), protocolError (2), timeLimitExceeded (3), sizeLimitExceeded (4), compareFalse (5), compareTrue (6), authMethodNotSupported (7), strongAuthRequired (8), -- 9 reserved -- + +Sermersheim Internet-Draft - Expires Apr 2004 Page 8 + Lightweight Directory Access Protocol Version 3 + referral (10), adminLimitExceeded (11), unavailableCriticalExtension (12), confidentialityRequired (13), - -Sermersheim Internet-Draft - Expires Mar 2004 Page 8 - Lightweight Directory Access Protocol Version 3 - saslBindInProgress (14), noSuchAttribute (16), undefinedAttributeType (17), inappropriateMatching (18), constraintViolation (19), attributeOrValueExists (20), invalidAttributeSyntax (21), -- 22-31 unused -- noSuchObject (32), aliasProblem (33), @@ -483,258 +483,259 @@ [LDAPIANA]. The meanings of the result codes are given in Appendix A. If a server detects multiple errors for an operation, only one result code is returned. The server should return the result code that best indicates the nature of the error encountered. The diagnosticMessage field of this construct may, at the server's option, be used to return a string containing a textual, human- readable (terminal control and page formatting characters should be avoided) diagnostic message. As this diagnostic message is not standardized, implementations MUST NOT rely on the values returned. - If the server chooses not to return a textual diagnostic, the - diagnosticMessage field of the LDAPResult type MUST contain a zero - length string. -Sermersheim Internet-Draft - Expires Mar 2004 Page 9 +Sermersheim Internet-Draft - Expires Apr 2004 Page 9 Lightweight Directory Access Protocol Version 3 + If the server chooses not to return a textual diagnostic, the + diagnosticMessage field MUST be empty. + For certain result codes (typically, but not restricted to noSuchObject, aliasProblem, invalidDNSyntax and aliasDereferencingProblem), the matchedDN field is set to the name of - the lowest entry (object or alias) in the directory that was matched. + the lowest entry (object or alias) in the Directory that was matched. If no aliases were dereferenced while attempting to locate the entry, this will be a truncated form of the name provided, or if aliases were dereferenced, of the resulting name, as defined in section 12.5 - of [X.511]. Unless otherwise defined, the matchedDN field contains a - zero length string with all other result codes. + of [X.511]. Otherwise the matchedDN field is empty. 4.1.10. Referral The referral result code indicates that the contacted server does not hold the target entry of the request. The referral field is present in an LDAPResult if the resultCode field value is referral, and absent with all other result codes. It contains one or more references to one or more servers or services that may be accessed via LDAP or other protocols. Referrals can be returned in response to any operation request (except unbind and abandon which do not have - responses). At least one URL MUST be present in the Referral. + responses). At least one URI MUST be present in the Referral. During a search operation, after the baseObject is located, and entries are being evaluated, the referral is not returned. Instead, continuation references, described in section 4.5.3, are returned when the search scope spans multiple naming contexts, and several different servers would need to be contacted to complete the operation. - Referral ::= SEQUENCE OF URL -- one or more + Referral ::= SEQUENCE SIZE (1..MAX) OF uri URI - URL ::= LDAPString -- limited to characters permitted in - -- URLs + URI ::= LDAPString -- limited to characters permitted in + -- URIs If the client wishes to progress the operation, it MUST follow the - referral by contacting one of the servers. If multiple URLs are - present, the client assumes that any URL may be used to progress the + referral by contacting one of the services. If multiple URIs are + present, the client assumes that any URI may be used to progress the operation. - A URL for a server implementing LDAP and accessible via [TCP]/[IP] + A URI for a server implementing LDAP and accessible via [TCP]/[IP] (v4 or v6) is written as an LDAP URL according to [LDAPURL]. When an LDAP URL is used, the following instructions are followed: - If an alias was dereferenced, the part of the URL MUST be present, with the new target object name. Note that UTF-8 characters appearing in a DN or search filter may not be legal for URLs (e.g. spaces) and MUST be escaped using the % method in - [RFC2396]. + [URI]. - If the part is present, the client MUST use this name in its next request to progress the operation, and if it is not present the client will use the same name as in the original request. -Sermersheim Internet-Draft - Expires Mar 2004 Page 10 +Sermersheim Internet-Draft - Expires Apr 2004 Page 10 Lightweight Directory Access Protocol Version 3 - Some servers (e.g. participating in distributed indexing) may provide a different filter in a URL of a referral for a search operation. - - If the filter part of the LDAP URL is present, the client MUST + - If the part of the LDAP URL is present, the client MUST use this filter in its next request to progress this search, and if it is not present the client MUST use the same filter as it used for that search. - - Other aspects of the new request may be the same or different as - the request which generated the referral. + - Other aspects of the new request may be the same as or different + from the request which generated the referral. - Other kinds of URLs may be returned, so long as the operation could - be performed using that protocol. The definition of such URLs and + Other kinds of URIs may be returned, so long as the operation could + be performed using that protocol. The definition of such URIs and instructions on their use is left to future specifications. 4.1.11. Controls A control is a way to specify extension information for an LDAP message. A control only alters the semantics of the message it is attached to. - Controls ::= SEQUENCE OF Control + Controls ::= SEQUENCE OF control Control Control ::= SEQUENCE { controlType LDAPOID, criticality BOOLEAN DEFAULT FALSE, controlValue OCTET STRING OPTIONAL } - The controlType field MUST be a UTF-8 encoded dotted-decimal + The controlType field is the UTF-8 encoded dotted-decimal representation of an OBJECT IDENTIFIER which uniquely identifies the - control. This prevents conflicts between control names. + control, or the request control and its paired response control. This + prevents conflicts between control names. The criticality field is either TRUE or FALSE and only applies to request messages that have a corresponding response message. For all other messages (such as abandonRequest, unbindRequest and all - response messages), the criticality field is treated as FALSE. + response messages), the criticality field SHOULD be FALSE. If the server recognizes the control type and it is appropriate for the operation, the server will make use of the control when performing the operation. If the server does not recognize the control type or it is not appropriate for the operation, and the criticality field is TRUE, the - server MUST NOT perform the operation, and MUST instead set the - resultCode to unavailableCriticalExtension. + server MUST NOT perform the operation, and for operations that have a + response, MUST set the resultCode to unavailableCriticalExtension. If the control is unrecognized or inappropriate but the criticality field is FALSE, the server MUST ignore the control. The controlValue contains any information associated with the control. Its format is defined by the specification of the control. Implementations MUST be prepared to handle arbitrary contents of the controlValue octet string, including zero bytes. It is absent only if -Sermersheim Internet-Draft - Expires Mar 2004 Page 11 +Sermersheim Internet-Draft - Expires Apr 2004 Page 11 Lightweight Directory Access Protocol Version 3 there is no value information which is associated with a control of its type. controlValues that are defined in terms of ASN.1 and BER encoded according to Section 5.1, also follow the extensibility rules in Section 4. + Servers list the controlType of all request controls they recognize + in the supportedControl attribute [Models] in the root DSE. + + Controls SHOULD NOT be combined unless the semantics of the + combination has been specified. The semantics of control + combinations, if specified, are generally found in the control + specification most recently published. In the absence of combination + semantics, the behavior of the operation is undefined. + Additionally, unless order-dependent semantics are given in a + specification, the order of a combination of controls in the SEQUENCE + is ignored. + This document does not specify any controls. Controls may be specified in other documents. The specification of a control consists of: - the OBJECT IDENTIFIER assigned to the control, - whether the control is always non critical, always critical, or - critical at the client's option, + optionally critical, - - the format of the controlValue contents of the control, + - whether there is information associated with the control, and if + so, the format of the controlValue contents, - - the semantics of the control, + - the semantics of the control, and - - and optionally, semantics regarding the combination of the control + - optionally, semantics regarding the combination of the control with other controls. - Servers list the controlType of all request controls they recognize - in the supportedControl attribute [Models] in the root DSE. - - Controls should not be combined unless the semantics of the - combination has been specified. The semantics of control - combinations, if specified, are generally found in the control - specification most recently published. In the absence of combination - semantics, the behavior of the operation is undefined. - Additionally, the order of a combination of controls in the SEQUENCE - is ignored unless the control specification(s) describe(s) - combination semantics. - 4.2. Bind Operation The function of the Bind Operation is to allow authentication - information to be exchanged between the client and server. Prior to - the first BindRequest, the implied identity is anonymous. Refer to - [AuthMeth] for the authentication-related semantics of this - operation. + information to be exchanged between the client and server. + Authentication and security-related semantics of this operation are + given in [AuthMeth]. The Bind Request is defined as follows: BindRequest ::= [APPLICATION 0] SEQUENCE { version INTEGER (1 .. 127), name LDAPDN, authentication AuthenticationChoice } AuthenticationChoice ::= CHOICE { simple [0] OCTET STRING, -- 1 and 2 reserved sasl [3] SaslCredentials, ... } -Sermersheim Internet-Draft - Expires Mar 2004 Page 12 +Sermersheim Internet-Draft - Expires Apr 2004 Page 12 Lightweight Directory Access Protocol Version 3 SaslCredentials ::= SEQUENCE { mechanism LDAPString, credentials OCTET STRING OPTIONAL } Parameters of the Bind Request are: - version: A version number indicating the version of the protocol to be used in this protocol association. This document describes version 3 of the LDAP protocol. Note that there is no version - negotiation, and the client just sets this parameter to the - version it desires. If the server does not support the specified - version, it MUST respond with protocolError in the resultCode - field of the BindResponse. + negotiation. The client sets this parameter to the version it + desires. If the server does not support the specified version, it + MUST respond with protocolError in the resultCode field of the + BindResponse. - - name: The name of the directory object that the client wishes to + - name: The name of the Directory object that the client wishes to bind as. This field may take on a null value (a zero length string) for the purposes of anonymous binds ([AuthMeth] section 7) - or when using SASL authentication ([AuthMeth] section 4.3). Server - behavior is undefined when the name is a null value, simple - authentication is used, and a password is specified. The server - SHOULD NOT perform any alias dereferencing in determining the - object to bind as. + or when using Simple Authentication and Security Layer [SASL] + authentication ([AuthMeth] section 4.3). Server behavior is + undefined when the name is a null value, simple authentication is + used, and a password is specified. The server SHALL NOT perform + alias dereferencing in determining the object to bind as. - authentication: information used to authenticate the name, if any, provided in the Bind Request. This type is extensible as defined in Section 3.6 of [LDAPIANA]. Servers that do not support a choice supplied by a client will return authMethodNotSupported in the - resultCode field of the BindResponse. The simple form of an - AuthenticationChoice specifies a simple password to be used for - authentication. To improve matching, applications SHOULD prepare - textual strings used as passwords. Applications which prepare - textural strings used as password are REQUIRED to prepare them by - transcoding the string to [Unicode], apply [SASLprep], and encode - as UTF-8. + resultCode field of the BindResponse. + The simple form of an AuthenticationChoice specifies a simple + password to be used for authentication. Passwords consisting of + character data (text passwords) SHALL be transferred as [UTF-8] + encoded [Unicode]. Prior to transfer, clients SHOULD prepare text + passwords by applying the [SASLprep] profile of the [Stringprep] + algorithm. Passwords consisting of other data (such as random + octets) MUST NOT be altered. Authorization is the use of this authentication information when performing operations. Authorization MAY be affected by factors - outside of the LDAP Bind Request, such as lower layer security - services. + outside of the LDAP Bind Request, such as those provided by lower + layer security services. 4.2.1. Processing of the Bind Request - Upon receipt of a BindRequest, the server MUST ensure there are no - outstanding operations in progress on the connection (this simplifies - server implementation). To do this, the server may cause them to be - abandoned or allow them to finish. The server then proceeds to - authenticate the client in either a single-step, or multi-step bind - process. Each step requires the server to return a BindResponse to - indicate the status of authentication. + Before processing a BindResponse, all outstanding operations MUST + either complete or be abandoned. The server may either wait for the + outstanding operations to complete, or abandon them. The server then + proceeds to authenticate the client in either a single-step, or + multi-step bind process. Each step requires the server to return a + BindResponse to indicate the status of authentication. If the client did not bind before sending a request and receives an - operationsError, it may then send a Bind Request. If this also fails + operationsError to that request, it may then send a Bind Request. If -Sermersheim Internet-Draft - Expires Mar 2004 Page 13 +Sermersheim Internet-Draft - Expires Apr 2004 Page 13 Lightweight Directory Access Protocol Version 3 - or the client chooses not to bind on the existing connection, it may - close the connection, reopen it and begin again by first sending a - PDU with a Bind Request. This will aid in interoperating with servers - implementing other versions of LDAP. + this also fails or the client chooses not to bind on the existing + connection, it may close the connection, reopen it and begin again by + first sending a PDU with a Bind Request. This will aid in + interoperating with servers implementing other versions of LDAP. - Clients MAY send multiple Bind Requests on a connection to change - their credentials. Authentication from earlier binds is subsequently + Clients may send multiple Bind Requests on a connection to change the + authentication and/or security associations or to complete a multi- + stage bind process. Authentication from earlier binds is subsequently ignored. For some SASL authentication mechanisms, it may be necessary for the client to invoke the BindRequest multiple times. This is indicated by the server sending a BindResponse with the resultCode set to saslBindInProgress. This indicates that the server requires the client to send a new bind request, with the same sasl mechanism, to continue the authentication process. If at any stage the client wishes to abort the bind process it MAY unbind and then drop the underlying connection. Clients MUST NOT invoke operations between two @@ -767,88 +768,87 @@ BindResponse ::= [APPLICATION 1] SEQUENCE { COMPONENTS OF LDAPResult, serverSaslCreds [7] OCTET STRING OPTIONAL } BindResponse consists simply of an indication from the server of the status of the client's request for authentication. A successful bind operation is indicated by a BindResponse with a resultCode set to success. Otherwise, an appropriate result code is - set in the BindResponse. For bind, the protocolError result code may -Sermersheim Internet-Draft - Expires Mar 2004 Page 14 +Sermersheim Internet-Draft - Expires Apr 2004 Page 14 Lightweight Directory Access Protocol Version 3 + set in the BindResponse. For bind, the protocolError result code may be used to indicate that the version number supplied by the client is unsupported. If the client receives a BindResponse response where the resultCode field is protocolError, it MUST close the connection as the server will be unwilling to accept further operations. (This is for compatibility with earlier versions of LDAP, in which the bind was always the first operation, and there was no negotiation.) The serverSaslCreds are used as part of a SASL-defined bind mechanism to allow the client to authenticate the server to which it is communicating, or to perform "challenge-response" authentication. If the client bound with the simple choice, or the SASL mechanism does not require the server to return information to the client, then this - field is not to be included in the BindResponse. + field SHALL NOT be included in the BindResponse. 4.3. Unbind Operation The function of the Unbind Operation is to terminate an LDAP association and connection. The Unbind Operation is defined as follows: UnbindRequest ::= [APPLICATION 2] NULL - The Unbind Operation has no response defined. Upon transmission of an - UnbindRequest, a protocol client MUST assume that the LDAP - association is terminated. Upon receipt of an UnbindRequest, a - protocol server MUST assume that the requesting client has terminated - the association and that all outstanding requests may be discarded, - and MUST close the connection. + The Unbind Operation has no response defined. Upon transmission of + the UnbindRequest, each protocol peer is to consider the LDAP + association terminated, MUST cease transmission of messages to the + other peer, and MUST close the connection. Any outstanding operations + on the server are, when possible, abandoned, and when not possible, + completed without transmission of the response. 4.4. Unsolicited Notification An unsolicited notification is an LDAPMessage sent from the server to the client which is not in response to any LDAPMessage received by the server. It is used to signal an extraordinary condition in the server or in the connection between the client and the server. The notification is of an advisory nature, and the server will not expect any response to be returned from the client. The unsolicited notification is structured as an LDAPMessage in which - the messageID is 0 and protocolOp is of the extendedResp form. The - responseName field of the ExtendedResponse is present. The LDAPOID - value MUST be unique for this notification, and not be used in any - other situation. + the messageID is zero and protocolOp is of the extendedResp form. The + responseName field of the ExtendedResponse always contains an LDAPOID + which is unique for this notification. One unsolicited notification (Notice of Disconnection) is defined in this document. 4.4.1. Notice of Disconnection -Sermersheim Internet-Draft - Expires Mar 2004 Page 15 +Sermersheim Internet-Draft - Expires Apr 2004 Page 15 Lightweight Directory Access Protocol Version 3 This notification may be used by the server to advise the client that the server is about to close the connection due to an error condition. Note that this notification is NOT a response to an unbind requested by the client: the server MUST follow the procedures of section 4.3. This notification is intended to assist clients in distinguishing between an error condition and a transient network failure. As with a connection close due to network failure, the client MUST NOT assume that any outstanding requests which modified - the directory have succeeded or failed. + the Directory have succeeded or failed. The responseName is 1.3.6.1.4.1.1466.20036, the response field is absent, and the resultCode is used to indicate the reason for the disconnection. The following result codes have these meanings when used in this notification: - protocolError: The server has received data from the client in which the LDAPMessage structure could not be parsed. @@ -856,103 +856,112 @@ - strongAuthRequired: The server has detected that an established security association between the client and server has unexpectedly failed or been compromised, or that the server now requires the client to authenticate using a strong(er) mechanism. - unavailable: This server will stop accepting new connections and operations on all existing connections, and be unavailable for an extended period of time. The client may make use of an alternative server. - After sending this notice, the server MUST close the connection. - After receiving this notice, the client MUST NOT transmit any further - on the connection, and may abruptly close the connection. + Upon transmission of the UnbindRequest, each protocol peer is to + consider the LDAP association terminated, MUST cease transmission of + messages to the other peer, and MUST close the connection. 4.5. Search Operation - The Search Operation allows a client to request that a search be - performed on its behalf by a server. This can be used to read - attributes from a single entry, from entries immediately below a - particular entry, or a whole subtree of entries. + The Search Operation is used to request a server to return, subject + to access controls and other restrictions, a set of entries matching + a complex search criterion. This can be used to read attributes from + a single entry, from entries immediately subordinate to a particular + entry, or a whole subtree of entries. 4.5.1. Search Request The Search Request is defined as follows: SearchRequest ::= [APPLICATION 3] SEQUENCE { baseObject LDAPDN, scope ENUMERATED { baseObject (0), singleLevel (1), wholeSubtree (2) }, - derefAliases ENUMERATED { -Sermersheim Internet-Draft - Expires Mar 2004 Page 16 +Sermersheim Internet-Draft - Expires Apr 2004 Page 16 Lightweight Directory Access Protocol Version 3 + derefAliases ENUMERATED { neverDerefAliases (0), derefInSearching (1), derefFindingBaseObj (2), derefAlways (3) }, sizeLimit INTEGER (0 .. maxInt), timeLimit INTEGER (0 .. maxInt), typesOnly BOOLEAN, filter Filter, attributes AttributeSelection } - AttributeSelection ::= SEQUENCE OF - LDAPString - -- constrained to the attributeSelection below + AttributeSelection ::= SEQUENCE OF selection LDAPString + -- constrained to the ABNF below Filter ::= CHOICE { - and [0] SET SIZE (1..MAX) OF Filter, - or [1] SET SIZE (1..MAX) OF Filter, + and [0] SET SIZE (1..MAX) OF filter Filter, + or [1] SET SIZE (1..MAX) OF filter Filter, not [2] Filter, equalityMatch [3] AttributeValueAssertion, substrings [4] SubstringFilter, greaterOrEqual [5] AttributeValueAssertion, lessOrEqual [6] AttributeValueAssertion, present [7] AttributeDescription, approxMatch [8] AttributeValueAssertion, extensibleMatch [9] MatchingRuleAssertion } SubstringFilter ::= SEQUENCE { type AttributeDescription, -- at least one must be present, -- initial and final can occur at most once - substrings SEQUENCE OF CHOICE { + substrings SEQUENCE SIZE (1..MAX) OF substring CHOICE { initial [0] AssertionValue, any [1] AssertionValue, final [2] AssertionValue } } MatchingRuleAssertion ::= SEQUENCE { matchingRule [1] MatchingRuleId OPTIONAL, type [2] AttributeDescription OPTIONAL, matchValue [3] AssertionValue, dnAttributes [4] BOOLEAN DEFAULT FALSE } Parameters of the Search Request are: - - baseObject: An LDAPDN that is the base object entry relative to - which the search is to be performed. + - baseObject: The name of the base object entry relative to which + the search is to be performed. - - scope: An indicator of the scope of the search to be performed. - The semantics of the possible values of this field are identical - to the semantics of the scope field in the X.511 Search Operation. + - scope: Specifies the scope of the search to be performed. The + semantics (as described in [X.511]) of the possible values of this + field are: + + baseObject: The scope is constrained to the entry named by + baseObject. + +Sermersheim Internet-Draft - Expires Apr 2004 Page 17 + Lightweight Directory Access Protocol Version 3 + + oneLevel: The scope is constrained to the immediate + subordinates of the entry named by baseObject. + + wholeSubtree: the scope is constrained to the entry named + by the baseObject, and all its subordinates. - derefAliases: An indicator as to how alias objects (as defined in [X.501]) are to be handled in searching. The semantics of the possible values of this field are: -Sermersheim Internet-Draft - Expires Mar 2004 Page 17 - Lightweight Directory Access Protocol Version 3 - neverDerefAliases: Do not dereference aliases in searching or in locating the base object of the search. derefInSearching: While searching, dereference any alias object subordinate to the base object which is also in the search scope. The filter is applied to the dereferenced object(s). If the search scope is wholeSubtree, the search continues in the subtree of any dereferenced object. Aliases in that subtree are also dereferenced. Servers SHOULD detect looping in this process to prevent denial of @@ -967,50 +976,51 @@ - sizeLimit: A size limit that restricts the maximum number of entries to be returned as a result of the search. A value of 0 in this field indicates that no client-requested size limit restrictions are in effect for the search. Servers may enforce a maximum number of entries to return. - timeLimit: A time limit that restricts the maximum time (in seconds) allowed for a search. A value of 0 in this field indicates that no client-requested time limit restrictions are in - effect for the search. + effect for the search. Servers may enforce a maximum time limit + for the search. - - typesOnly: An indicator as to whether search results will contain - both attribute descriptions and values, or just attribute + - typesOnly: An indicator as to whether search results are to + contain both attribute descriptions and values, or just attribute descriptions. Setting this field to TRUE causes only attribute descriptions (no values) to be returned. Setting this field to FALSE causes both attribute descriptions and values to be returned. - filter: A filter that defines the conditions that must be fulfilled in order for the search to match a given entry. The 'and', 'or' and 'not' choices can be used to form combinations of filters. At least one filter element MUST be present in an + +Sermersheim Internet-Draft - Expires Apr 2004 Page 18 + Lightweight Directory Access Protocol Version 3 + 'and' or 'or' choice. The others match against individual attribute values of entries in the scope of the search. (Implementor's note: the 'not' filter is an example of a tagged choice in an implicitly-tagged module. In BER this is treated as if the tag was explicit.) A server MUST evaluate filters according to the three-valued logic of X.511 (1993) section 7.8.1. In summary, a filter is evaluated to either "TRUE", "FALSE" or "Undefined". If the filter evaluates to TRUE for a particular entry, then the attributes of that entry are returned as part of the search result (subject to any applicable access control restrictions). If the filter evaluates - -Sermersheim Internet-Draft - Expires Mar 2004 Page 18 - Lightweight Directory Access Protocol Version 3 - to FALSE or Undefined, then the entry is ignored for the search. A filter of the "and" choice is TRUE if all the filters in the SET OF evaluate to TRUE, FALSE if at least one filter is FALSE, and otherwise Undefined. A filter of the "or" choice is FALSE if all of the filters in the SET OF evaluate to FALSE, TRUE if at least one filter is TRUE, and Undefined otherwise. A filter of the "not" choice is TRUE if the filter being negated is FALSE, FALSE if it is TRUE, and Undefined if it is Undefined. @@ -1027,564 +1037,547 @@ Note that the AssertionValue in a substrings filter item MUST conform to the assertion syntax of the EQUALITY matching rule for the attribute type rather than the assertion syntax of the SUBSTR matching rule for the attribute type. The entire SubstringFilter is converted into an assertion value of the substrings matching rule prior to applying the rule. The matching rule for greaterOrEqual and lessOrEqual filter items is defined by the ORDERING matching rule for the attribute type. - The matching semantics for approxMatch filter items is - implementation-defined. If approximate matching is not supported - by the server, the filter item should be treated as an - equalityMatch. + The approxMatch evaluates to TRUE when there is a value of the + attribute or subtype for which some locally-defined approximate + matching algorithm (e.g. spelling variations, phonetic match, + etc.) returns TRUE. If an item matches for equality, it also + satisfies an approximate match. If approximate matching is not + supported, this filter item should be treated as an equalityMatch. - The extensibleMatch is new in this version of LDAP. If the - matchingRule field is absent, the type field MUST be present, and - the equality match is performed for that type. If the type field - is absent and matchingRule is present, the matchValue is compared - against all attributes in an entry which support that - matchingRule, and the matchingRule determines the syntax for the - assertion value (the filter item evaluates to TRUE if it matches - with at least one attribute in the entry, FALSE if it does not - match any attribute in the entry, and Undefined if the - matchingRule is not recognized or the assertionValue cannot be - parsed.) If the type field is present and matchingRule is present, - the matchingRule MUST be one permitted for use with that type, - otherwise the filter item is undefined. If the dnAttributes field - is set to TRUE, the match is applied against all the - AttributeValueAssertions in an entry's distinguished name as well, - and also evaluates to TRUE if there is at least one attribute in - the distinguished name for which the filter item evaluates to - TRUE. (Editors note: The dnAttributes field is present so that - there does not need to be multiple versions of generic matching + An extensibleMatch is evaluated as follows: -Sermersheim Internet-Draft - Expires Mar 2004 Page 19 + If the matchingRule field is absent, the type field MUST be + present, and an equality match is performed for that type. + +Sermersheim Internet-Draft - Expires Apr 2004 Page 19 Lightweight Directory Access Protocol Version 3 - rules such as for word matching, one to apply to entries and - another to apply to entries and dn attributes as well). + If the type field is absent and the matchingRule is present, the + matchValue is compared against all attributes in an entry which + support that matchingRule. The matchingRule determines the + syntax for the assertion value. The filter item evaluates to + TRUE if it matches with at least one attribute in the entry, + FALSE if it does not match any attribute in the entry, and + Undefined if the matchingRule is not recognized or the + assertionValue is invalid. + + If the type field is present and the matchingRule is present, + the matchValue is compared against entry attributes of the + specified type. In this case, the matchingRule MUST be one + suitable for use with the specified type (see [Syntaxes]), + otherwise the filter item is undefined. + + If the dnAttributes field is set to TRUE, the match is + additionally applied against all the AttributeValueAssertions in + an entry's distinguished name, and evaluates to TRUE if there is + at least one attribute in the distinguished name for which the + filter item evaluates to TRUE. The dnAttributes field is present + to alleviate the need for multiple versions of generic matching + rules (such as word matching), where one applies to entries and + another applies to entries and dn attributes as well. A filter item evaluates to Undefined when the server would not be able to determine whether the assertion value matches an entry. If an attribute description in an equalityMatch, substrings, greaterOrEqual, lessOrEqual, approxMatch or extensibleMatch filter is not recognized by the server, a matching rule id in the extensibleMatch is not recognized by the server, the assertion - value cannot be parsed, or the type of filtering requested is not + value is invalid, or the type of filtering requested is not implemented, then the filter is Undefined. Thus for example if a server did not recognize the attribute type shoeSize, a filter of (shoeSize=*) would evaluate to FALSE, and the filters (shoeSize=12), (shoeSize>=12) and (shoeSize<=12) would evaluate to Undefined. Servers MUST NOT return errors if attribute descriptions or - matching rule ids are not recognized, or assertion values cannot - be parsed. More details of filter processing are given in section - 7.8 of [X.511]. + matching rule ids are not recognized, assertion values are + invalid, or the assertion syntax is not supported. More details of + filter processing are given in section 7.8 of [X.511]. - attributes: A list of the attributes to be returned from each entry which matches the search filter. LDAPString values of this field are constrained to the following ABNF: attributeSelection = noattrs / *( attributedescription / specialattr ) noattrs = %x31 %x2E %x31 ; "1.1" - attributedescription = ; attributedescription from 2.5 of [Models] - specialattr = ASTERISK ASTERISK = %x2A ; asterisk ("*") +Sermersheim Internet-Draft - Expires Apr 2004 Page 20 + Lightweight Directory Access Protocol Version 3 + + is defined in Section 2.5 of [Models]. + There are two special values which may be used: an empty list with no attributes, and the attribute description string "*". Both of these signify that all user attributes are to be returned. (The "*" allows the client to request all user attributes in addition - to any specified operational attributes). + to any specified operational attributes). Client implementors + should note that even if all user attributes are requested, some + attributes and or attribute values of the entry may not be + included in search results due to access controls or other + restrictions. Furthermore, servers will not return operational + attributes, such as objectClasses or attributeTypes, unless they + are listed by name. Operational attributes are described in + [Models]. - Attributes MUST be named at most once in the list, and are + Attributes MUST NOT be named more than once in the list, and are returned at most once in an entry. If there are attribute descriptions in the list which are not recognized, they are ignored by the server. If the client does not want any attributes returned, it can specify a list containing only the attribute with OID "1.1". This - OID was chosen arbitrarily and does not correspond to any + OID was chosen because it does not (and can not) correspond to any attribute in use. - Client implementors should note that even if all user attributes - are requested, some attributes of the entry may not be included in - -Sermersheim Internet-Draft - Expires Mar 2004 Page 20 - Lightweight Directory Access Protocol Version 3 - - search results due to access controls or other restrictions. - Furthermore, servers will not return operational attributes, such - as objectClasses or attributeTypes, unless they are listed by - name, since there may be extremely large number of values for - certain operational attributes. (A list of operational attributes - for use in LDAP is given in [Syntaxes].) - Note that an X.500 "list"-like operation can be emulated by the client requesting a one-level LDAP search operation with a filter checking for the presence of the objectClass attribute, and that an X.500 "read"-like operation can be emulated by a base object LDAP search operation with the same filter. A server which provides a gateway to X.500 is not required to use the Read or List operations, although it may choose to do so, and if it does, it must provide the same semantics as the X.500 search operation. 4.5.2. Search Result - The results of the search attempted by the server upon receipt of a - Search Request are returned in Search Responses, which are LDAP - messages containing SearchResultEntry, SearchResultReference, or - SearchResultDone data types. + The results of the search operation are returned as zero or more + searchResultEntry messages, zero or more SearchResultReference + messages, followed by a single searchResultDone message. SearchResultEntry ::= [APPLICATION 4] SEQUENCE { objectName LDAPDN, attributes PartialAttributeList } - PartialAttributeList ::= SEQUENCE OF SEQUENCE { - type AttributeDescription, - vals SET OF AttributeValue } - -- implementors should note that the PartialAttributeList may - -- have zero elements (if none of the attributes of that entry - -- were requested, or could be returned), and that the vals set - -- may also have zero elements (if types only was requested, or - -- all values were excluded from the result.) + PartialAttributeList ::= SEQUENCE OF + attribute PartialAttribute + -- Note that the PartialAttributeList may hold zero elements. + -- This may happen when none of the attributes of an entry + -- were requested, or could be returned. - SearchResultReference ::= [APPLICATION 19] SEQUENCE OF URL - -- at least one URL element must be present + PartialAttribute ::= SEQUENCE { + type AttributeDescription, - SearchResultDone ::= [APPLICATION 5] LDAPResult +Sermersheim Internet-Draft - Expires Apr 2004 Page 21 + Lightweight Directory Access Protocol Version 3 - Upon receipt of a Search Request, a server will perform the necessary - search of the DIT. + vals SET OF value AttributeValue } + -- Note that the vals set may hold zero elements. + -- This may happen when typesOnly is requested, access controls + -- prevent the return of values, or other reasons. - The server will return to the client a sequence of responses in - separate LDAP messages. There may be zero or more responses - containing SearchResultEntry, one for each entry found during the - search. There may also be zero or more responses containing - SearchResultReference, one for each area not explored by this server - during the search. The SearchResultEntry and SearchResultReference - PDUs may come in any order. Following all the SearchResultReference - responses and all SearchResultEntry responses to be returned by the - server, the server will return a response containing the + SearchResultReference ::= [APPLICATION 19] SEQUENCE + SIZE (1..MAX) OF uri URI -Sermersheim Internet-Draft - Expires Mar 2004 Page 21 - Lightweight Directory Access Protocol Version 3 + SearchResultDone ::= [APPLICATION 5] LDAPResult - SearchResultDone, which contains an indication of success, or - detailing any errors that have occurred. + Each SearchResultEntry represents an entry found during the search. + Each SearchResultReference represents an area not yet explored during + the search. The SearchResultEntry and SearchResultReference PDUs may + come in any order. Following all the SearchResultReference and + SearchResultEntry responses, the server returns a SearchResultDone + response, which contains an indication of success, or detailing any + errors that have occurred. Each entry returned in a SearchResultEntry will contain all appropriate attributes as specified in the attributes field of the Search Request. Return of attributes is subject to access control and other administrative policy. Some attributes may be constructed by the server and appear in a SearchResultEntry attribute list, although they are not stored attributes of an entry. Clients SHOULD NOT assume that all attributes can be modified, even if permitted by access control. - If the server's schema defines a textual name for an attribute type, - it SHOULD use a textual name for attributes of that attribute type by - specifying one of the textual names as the value of the attribute - type. Otherwise, the server uses the object identifier for the - attribute type by specifying the object identifier, in ldapOID form, - as the value of attribute type. If the server determines that - returning a textual name will cause interoperability problems, it - SHOULD return the ldapOID form of the attribute type. + If the server's schema defines short names [Models] for an attribute + type then the server SHOULD use one of those names in attribute + descriptions for that attribute type (in preference to using the + [Models] format of the attribute type's object + identifier). The server SHOULD NOT use the short name if that name is + known by the server to be ambiguous, or otherwise likely to cause + interoperability problems. 4.5.3. Continuation References in the Search Result If the server was able to locate the entry referred to by the baseObject but was unable to search all the entries in the scope at - and under the baseObject, the server may return one or more + and subordinate to the baseObject, the server may return one or more SearchResultReference entries, each containing a reference to another set of servers for continuing the operation. A server MUST NOT return any SearchResultReference if it has not located the baseObject and thus has not searched any entries; in this case it would return a SearchResultDone containing a referral result code. If a server holds a copy or partial copy of the subordinate naming context, it may use the search filter to determine whether or not to return a SearchResultReference response. Otherwise SearchResultReference responses are always returned when in scope. The SearchResultReference is of the same data type as the Referral. - A URL for a server implementing LDAP and accessible via [TCP]/[IP] +Sermersheim Internet-Draft - Expires Apr 2004 Page 22 + Lightweight Directory Access Protocol Version 3 + + A URI for a server implementing LDAP and accessible via [TCP]/[IP] (v4 or v6) is written as an LDAP URL according to [LDAPURL]. When an LDAP URL is used, the following instructions are followed: - The part of the URL MUST be present, with the new target object name. The client MUST use this name when following the referral. Note that UTF-8 characters appearing in a DN or search filter may not be legal for URLs (e.g. spaces) and MUST be - escaped using the % method in [RFC2396]. + escaped using the % method in [URI]. - Some servers (e.g. participating in distributed indexing) may provide a different filter in a URL of a SearchResultReference. - - If the filter part of the URL is present, the client MUST use + - If the part of the URL is present, the client MUST use this filter in its next request to progress this search, and if - -Sermersheim Internet-Draft - Expires Mar 2004 Page 22 - Lightweight Directory Access Protocol Version 3 - it is not present the client MUST use the same filter as it used for that search. - - If the originating search scope was singleLevel, the scope part - of the URL will be baseObject. - - Other aspects of the new search request may be the same or - different as the search request which generated the + - If the originating search scope was singleLevel, the + part of the URL will be "base". + - Other aspects of the new search request may be the same as or + different from the search request which generated the SearchResultReference. - The name of an unexplored subtree in a SearchResultReference need not be subordinate to the base object. - Other kinds of URLs may be returned, so long as the operation could - be performed using that protocol. The definition of such URLs and + Other kinds of URIs may be returned, so long as the operation could + be performed using that protocol. The definition of such URIs and instructions on their use is left to future specifications. - In order to complete the search, the client MUST issue a new search + In order to complete the search, the client issues a new search operation for each SearchResultReference that is returned. Note that the abandon operation described in section 4.11 applies only to a particular operation sent on an association between a client and - server, and if the client has multiple outstanding search operations, - it MUST abandon each operation individually. + server. The client must abandon subsequent search operations it + wishes to individually. 4.5.3.1. Example For example, suppose the contacted server (hosta) holds the entry "DC=Example,DC=NET" and the entry "CN=Manager,DC=Example,DC=NET". It knows that either LDAP-capable servers (hostb) or (hostc) hold "OU=People,DC=Example,DC=NET" (one is the master and the other server a shadow), and that LDAP-capable server (hostd) holds the subtree "OU=Roles,DC=Example,DC=NET". If a subtree search of "DC=Example,DC=NET" is requested to the contacted server, it may return the following: SearchResultEntry for DC=Example,DC=NET SearchResultEntry for CN=Manager,DC=Example,DC=NET SearchResultReference { ldap://hostb/OU=People,DC=Example,DC=NET ldap://hostc/OU=People,DC=Example,DC=NET } SearchResultReference { ldap://hostd/OU=Roles,DC=Example,DC=NET } + +Sermersheim Internet-Draft - Expires Apr 2004 Page 23 + Lightweight Directory Access Protocol Version 3 + SearchResultDone (success) Client implementors should note that when following a SearchResultReference, additional SearchResultReference may be generated. Continuing the example, if the client contacted the server (hostb) and issued the search for the subtree "OU=People,DC=Example,DC=NET", the server might respond as follows: SearchResultEntry for OU=People,DC=Example,DC=NET SearchResultReference { ldap://hoste/OU=Managers,OU=People,DC=Example,DC=NET } SearchResultReference { ldap://hostf/OU=Consultants,OU=People,DC=Example,DC=NET } SearchResultDone (success) -Sermersheim Internet-Draft - Expires Mar 2004 Page 23 - Lightweight Directory Access Protocol Version 3 - If the contacted server does not hold the base object for the search, then it will return a referral to the client. For example, if the client requests a subtree search of "DC=Example,DC=ORG" to hosta, the server may return only a SearchResultDone containing a referral. SearchResultDone (referral) { ldap://hostg/DC=Example,DC=ORG??sub } 4.6. Modify Operation The Modify Operation allows a client to request that a modification of an entry be performed on its behalf by a server. The Modify Request is defined as follows: ModifyRequest ::= [APPLICATION 6] SEQUENCE { object LDAPDN, - changes SEQUENCE OF SEQUENCE { + changes SEQUENCE OF change SEQUENCE { operation ENUMERATED { add (0), delete (1), replace (2) }, - modification Attribute } } + modification PartialAttribute } } Parameters of the Modify Request are: - - object: The object to be modified. The value of this field - contains the DN of the entry to be modified. The server will not - perform any alias dereferencing in determining the object to be - modified. + - object: The name of the object to be modified. The value of this + field contains the DN of the entry to be modified. The server + SHALL NOT perform any alias dereferencing in determining the + object to be modified. - changes: A list of modifications to be performed on the entry. The entire list of modifications MUST be performed in the order they are listed, as a single atomic operation. While individual modifications may violate certain aspects of the directory schema (such as the object class definition and DIT content rule), the resulting entry after the entire list of modifications is performed MUST conform to the requirements of the directory schema. +Sermersheim Internet-Draft - Expires Apr 2004 Page 24 + Lightweight Directory Access Protocol Version 3 + - operation: Used to specify the type of modification being performed. Each operation type acts on the following modification. The values of this field have the following semantics respectively: add: add values listed to the modification attribute, creating the attribute if necessary; delete: delete values listed from the modification attribute, removing the entire attribute if no values are listed, or if all current values of the attribute are listed for deletion; -Sermersheim Internet-Draft - Expires Mar 2004 Page 24 - Lightweight Directory Access Protocol Version 3 - replace: replace all existing values of the modification attribute with the new values listed, creating the attribute if it did not already exist. A replace with no value will delete the entire attribute if it exists, and is ignored if the attribute does not exist. - - modification: An Attribute (which may have an empty SET of vals) - used to hold the Attribute Type or Attribute Type and values - being modified. + - modification: A PartialAttribute (which may have an empty SET of + vals) used to hold the attribute type or attribute type and + values being modified. - The result of the modification attempted by the server upon receipt - of a Modify Request is returned in a Modify Response, defined as - follows: + Upon receipt of a Modify Request, the server attempts to perform the + necessary modifications to the DIT and returns the result in a Modify + Response, defined as follows: ModifyResponse ::= [APPLICATION 7] LDAPResult - Upon receipt of a Modify Request, a server will perform the necessary - modifications to the DIT. - The server will return to the client a single Modify Response indicating either the successful completion of the DIT modification, or the reason that the modification failed. Note that due to the requirement for atomicity in applying the list of modifications in the Modify Request, the client may expect that no modifications of the DIT have been performed if the Modify Response received indicates any sort of error, and that all requested modifications have been performed if the Modify Response indicates successful completion of the Modify Operation. If the association changes or the connection fails, whether the modification occurred or not is indeterminate. The Modify Operation cannot be used to remove from an entry any of - its distinguished values, those values which form the entry's + its distinguished values, i.e. those values which form the entry's relative distinguished name. An attempt to do so will result in the server returning the notAllowedOnRDN result code. The Modify DN Operation described in section 4.9 is used to rename an entry. Note that due to the simplifications made in LDAP, there is not a direct mapping of the changes in an LDAP ModifyRequest onto the changes of a DAP ModifyEntry operation, and different implementations of LDAP-DAP gateways may use different means of representing the change. If successful, the final effect of the operations on the entry MUST be identical. +Sermersheim Internet-Draft - Expires Apr 2004 Page 25 + Lightweight Directory Access Protocol Version 3 + 4.7. Add Operation The Add Operation allows a client to request the addition of an entry - into the directory. The Add Request is defined as follows: + into the Directory. The Add Request is defined as follows: AddRequest ::= [APPLICATION 8] SEQUENCE { entry LDAPDN, attributes AttributeList } - AttributeList ::= SEQUENCE OF SEQUENCE { - -Sermersheim Internet-Draft - Expires Mar 2004 Page 25 - Lightweight Directory Access Protocol Version 3 - - type AttributeDescription, - vals SET OF AttributeValue } + AttributeList ::= SEQUENCE OF attribute Attribute Parameters of the Add Request are: - - entry: the Distinguished Name of the entry to be added. Note that - the server will not dereference any aliases in locating the entry - to be added. + - entry: the name of the entry to be added. Note that the server + SHALL NOT dereference any aliases in locating the entry to be + added. - attributes: the list of attributes that make up the content of the entry being added. Clients MUST include distinguished values (those forming the entry's own RDN) in this list, the objectClass attribute, and values of any mandatory attributes of the listed object classes. Clients MUST NOT supply NO-USER-MODIFICATION attributes such as the createTimestamp or creatorsName attributes, since the server maintains these automatically. The entry named in the entry field of the AddRequest MUST NOT exist - for the AddRequest to succeed. The immediate superior (parent) of the - object and alias entries to be added MUST exist. For example, if the + for the AddRequest to succeed. The immediate superior (parent) of an + object or alias entry to be added MUST exist. For example, if the client attempted to add "CN=JS,DC=Example,DC=NET", the "DC=Example,DC=NET" entry did not exist, and the "DC=NET" entry did exist, then the server would return the noSuchObject result code with the matchedDN field containing "DC=NET". If the parent entry exists but is not in a naming context held by the server, the server SHOULD return a referral to the server holding the parent entry. Server implementations SHOULD NOT restrict where entries can be - located in the directory unless DIT structure rules are in place. - Some servers MAY allow the administrator to restrict the classes of - entries which can be added to the directory. + located in the Directory unless DIT structure rules are in place. + Some servers allow the administrator to restrict the classes of + entries which can be added to the Directory. Upon receipt of an Add Request, a server will attempt to add the requested entry. The result of the add attempt will be returned to the client in the Add Response, defined as follows: AddResponse ::= [APPLICATION 9] LDAPResult A response of success indicates that the new entry is present in the - directory. + Directory. 4.8. Delete Operation +Sermersheim Internet-Draft - Expires Apr 2004 Page 26 + Lightweight Directory Access Protocol Version 3 + The Delete Operation allows a client to request the removal of an - entry from the directory. The Delete Request is defined as follows: + entry from the Directory. The Delete Request is defined as follows: DelRequest ::= [APPLICATION 10] LDAPDN - The Delete Request consists of the Distinguished Name of the entry to - be deleted. Note that the server will not dereference aliases while - resolving the name of the target entry to be removed, and that only - leaf entries (those with no subordinate entries) can be deleted with - this operation. + The Delete Request consists of the name of the entry to be deleted. + The server SHALL NOT dereference aliases while resolving the name of + the target entry to be removed. -Sermersheim Internet-Draft - Expires Mar 2004 Page 26 - Lightweight Directory Access Protocol Version 3 + Only leaf entries (those with no subordinate entries) can be deleted + with this operation. - The result of the delete attempted by the server upon receipt of a - Delete Request is returned in the Delete Response, defined as - follows: + Upon receipt of a Delete Request, a server will attempt to perform + the entry removal requested and return the result in the Delete + Response defined as follows: DelResponse ::= [APPLICATION 11] LDAPResult - Upon receipt of a Delete Request, a server will attempt to perform - the entry removal requested. The result of the delete attempt will be - returned to the client in the Delete Response. - 4.9. Modify DN Operation - The Modify DN Operation allows a client to change the leftmost (least - significant) component of the name of an entry in the directory, - and/or to move a subtree of entries to a new location in the - directory. The Modify DN Request is defined as follows: + The Modify DN Operation allows a client to change the Relative + Distinguished Name (RDN) of an entry in the Directory, and/or to move + a subtree of entries to a new location in the Directory. The Modify + DN Request is defined as follows: ModifyDNRequest ::= [APPLICATION 12] SEQUENCE { entry LDAPDN, newrdn RelativeLDAPDN, deleteoldrdn BOOLEAN, newSuperior [0] LDAPDN OPTIONAL } Parameters of the Modify DN Request are: - - entry: the Distinguished Name of the entry to be changed. This - entry may or may not have subordinate entries. Note that the - server will not dereference any aliases in locating the entry to - be changed. + - entry: the name of the entry to be changed. This entry may or may + not have subordinate entries. Note that the server SHALL NOT + dereference any aliases in locating the entry to be changed. - - newrdn: the RDN that will form the leftmost component of the new - name of the entry. + - newrdn: the new RDN of the entry. - deleteoldrdn: a boolean parameter that controls whether the old RDN attribute values are to be retained as attributes of the entry, or deleted from the entry. - - newSuperior: if present, this is the Distinguished Name of an - existing object entry which becomes the immediate superior - (parent)of the existing entry. + - newSuperior: if present, this is the name of an existing object + entry which becomes the immediate superior (parent) of the + existing entry. - The result of the name change attempted by the server upon receipt of - a Modify DN Request is returned in the Modify DN Response, defined as - follows: + Upon receipt of a ModifyDNRequest, a server will attempt to perform + the name change and return the result in the Modify DN Response, + defined as follows: ModifyDNResponse ::= [APPLICATION 13] LDAPResult - Upon receipt of a ModifyDNRequest, a server will attempt to perform - the name change. The result of the name change attempt will be - returned to the client in the Modify DN Response. - -Sermersheim Internet-Draft - Expires Mar 2004 Page 27 +Sermersheim Internet-Draft - Expires Apr 2004 Page 27 Lightweight Directory Access Protocol Version 3 For example, if the entry named in the "entry" parameter was "cn=John Smith,c=US", the newrdn parameter was "cn=John Cougar Smith", and the newSuperior parameter was absent, then this operation would attempt to rename the entry to be "cn=John Cougar Smith,c=US". If there was already an entry with that name, the operation would fail with the entryAlreadyExists result code. The object named in newSuperior MUST exist. For example, if the client attempted to add "CN=JS,DC=Example,DC=NET", the "DC=Example,DC=NET" entry did not exist, and the "DC=NET" entry did exist, then the server would return the noSuchObject result code with the matchedDN field containing "DC=NET". If the deleteoldrdn parameter is TRUE, the values forming the old RDN are deleted from the entry. If the deleteoldrdn parameter is FALSE, the values forming the old RDN will be retained as non-distinguished - attribute values of the entry. The server may not perform the - operation and return an error in the result code if the setting of - the deleteoldrdn parameter would cause a schema inconsistency in the - entry. + attribute values of the entry. The server MUST fail the operation and + return an error in the result code if the setting of the deleteoldrdn + parameter would cause a schema inconsistency in the entry. Note that X.500 restricts the ModifyDN operation to only affect entries that are contained within a single server. If the LDAP server is mapped onto DAP, then this restriction will apply, and the affectsMultipleDSAs result code will be returned if this error - occurred. In general clients MUST NOT expect to be able to perform - arbitrary movements of entries and subtrees between servers. + occurred. In general, clients MUST NOT expect to be able to perform + arbitrary movements of entries and subtrees between servers or + between naming contexts. 4.10. Compare Operation The Compare Operation allows a client to compare an assertion - provided with an entry in the directory. The Compare Request is + provided with an entry in the Directory. The Compare Request is defined as follows: CompareRequest ::= [APPLICATION 14] SEQUENCE { entry LDAPDN, ava AttributeValueAssertion } Parameters of the Compare Request are: - - entry: the name of the entry to be compared with. Note that the - server SHOULD NOT dereference any aliases in locating the entry to - be compared with. + - entry: the name of the entry to be compared. Note that the server + SHALL NOT dereference any aliases in locating the entry to be + compared. - ava: the assertion with which an attribute in the entry is to be compared. - The result of the compare attempted by the server upon receipt of a - Compare Request is returned in the Compare Response, defined as - follows: + Upon receipt of a Compare Request, a server will attempt to perform + the requested comparison using the EQUALITY matching rule for the + attribute type and return the result in the Compare Response, defined + as follows: CompareResponse ::= [APPLICATION 15] LDAPResult -Sermersheim Internet-Draft - Expires Mar 2004 Page 28 +Sermersheim Internet-Draft - Expires Apr 2004 Page 28 Lightweight Directory Access Protocol Version 3 - Upon receipt of a Compare Request, a server will attempt to perform - the requested comparison using the EQUALITY matching rule for the - attribute type. The result of the comparison will be returned to the - client in the Compare Response. In the event that the attribute or - subtype is not present in the entry, the resultCode field is set to - noSuchAttribute. If the attribute is unknown, the resultCode is set - to undefinedAttributeType. Note that errors and the result of - comparison are all returned in the same construct. + In the event that the attribute or subtype is not present in the + entry, the resultCode field is set to noSuchAttribute. If the + attribute is unknown, the resultCode is set to + undefinedAttributeType. Note that errors and the result of comparison + are all returned in the same construct. Note that some directory systems may establish access controls which permit the values of certain attributes (such as userPassword) to be compared but not interrogated by other means. 4.11. Abandon Operation The function of the Abandon Operation is to allow a client to request that the server abandon an outstanding operation. The Abandon Request is defined as follows: @@ -1592,52 +1585,49 @@ AbandonRequest ::= [APPLICATION 16] MessageID The MessageID MUST be that of an operation which was requested earlier in this LDAP association. The abandon request itself has its own message id. This is distinct from the id of the earlier operation being abandoned. There is no response defined in the Abandon operation. Upon receipt of an AbandonRequest, the server MAY abandon the operation identified by the MessageID. Operation responses are not sent for successfully - abandoned operations, thus a client SHOULD NOT use the Abandon - operation when it needs an indication of whether the operation was - abandoned. For example, if a client performs an update operation - (Add, Modify, or ModifyDN), and it needs to know whether the - directory has changed due to the operation, it should not use the - Abandon operation to cancel the update operation. + abandoned operations, thus the application of the Abandon operation + is limited to uses where the client does not require an indication of + its outcome. Abandon and Unbind operations cannot be abandoned. The ability to abandon other (particularly update) operations is at the discretion of the server. In the event that a server receives an Abandon Request on a Search Operation in the midst of transmitting responses to the search, that server MUST cease transmitting entry responses to the abandoned request immediately, and MUST NOT send the SearchResponseDone. Of course, the server MUST ensure that only properly encoded LDAPMessage PDUs are transmitted. Clients MUST NOT send abandon requests for the same operation multiple times, and MUST also be prepared to receive results from operations it has abandoned (since these may have been in transit when the abandon was requested, or are not able to be abandoned). -Sermersheim Internet-Draft - Expires Mar 2004 Page 29 - Lightweight Directory Access Protocol Version 3 - Servers MUST discard abandon requests for message IDs they do not recognize, for operations which cannot be abandoned, and for operations which have already been abandoned. 4.12. Extended Operation +Sermersheim Internet-Draft - Expires Apr 2004 Page 29 + Lightweight Directory Access Protocol Version 3 + An extension mechanism has been added in this version of LDAP, in order to allow additional operations to be defined for services not available elsewhere in this protocol, for instance digitally signed operations and results. The extended operation allows clients to make requests and receive responses with predefined syntaxes and semantics. These may be defined in RFCs or be private to particular implementations. Each request MUST have a unique OBJECT IDENTIFIER assigned to it. @@ -1672,31 +1662,28 @@ Extended operations may be specified in other documents. The specification of an extended operation consists of: - the OBJECT IDENTIFIER assigned to the ExtendedRequest.requestName (and possibly ExtendedResponse.responseName), - the format of the contents of the requestValue and responseValue (if any), -Sermersheim Internet-Draft - Expires Mar 2004 Page 30 - Lightweight Directory Access Protocol Version 3 - - the semantics of the operation, - Servers list the requestName of all ExtendedRequests they recognize - in the supportedExtension attribute [Models] in the root DSE. + It is RECOMMENDED that servers list the requestName of + ExtendedRequests they support in the supportedExtension attribute + [Models] in the root DSE. - requestValues and responseValues that are defined in terms of ASN.1 - and BER encoded according to Section 5.1, also follow the - extensibility rules in Section 4. +Sermersheim Internet-Draft - Expires Apr 2004 Page 30 + Lightweight Directory Access Protocol Version 3 4.13. Start TLS Operation The Start Transport Layer Security (StartTLS) operation provides the ability to establish Transport Layer Security [RFC2246] on an LDAP connection. 4.13.1. Start TLS Request A client requests TLS establishment by transmitting a Start TLS @@ -1726,94 +1713,100 @@ 4.13.2.2. Response other than "success" If the ExtendedResponse contains a result code other than success, this indicates that the server is unwilling or unable to negotiate TLS. The following result codes have these meanings for this operation: - operationsError: operations sequencing incorrect; e.g. TLS already established) -Sermersheim Internet-Draft - Expires Mar 2004 Page 31 - Lightweight Directory Access Protocol Version 3 - - protocolError: (TLS not supported or incorrect PDU structure) - unavailable: (e.g. some major problem with TLS, or server is shutting down) The server MUST return operationsError if the client violates any of the Start TLS extended operation sequencing requirements described in section 5.3 of [AuthMeth]. +Sermersheim Internet-Draft - Expires Apr 2004 Page 31 + Lightweight Directory Access Protocol Version 3 + If the server does not support TLS (whether by design or by current configuration), it MUST set the resultCode field to protocolError. The client's current association is unaffected if the server does not - support TLS. The client MAY proceed with any LDAP operation, or it - MAY close the connection. + support TLS. The client may proceed with any LDAP operation, or it + may close the connection. The server MUST return unavailable if it supports TLS but cannot establish a TLS connection for some reason, e.g. the certificate server not responding, it cannot contact its TLS implementation, or - if the server is in process of shutting down. The client MAY retry - the StartTLS operation, or it MAY proceed with any other LDAP - operation, or it MAY close the LDAP connection. + if the server is in process of shutting down. The client may retry + the StartTLS operation, or it may proceed with any other LDAP + operation, or it may close the LDAP connection. 4.13.3. Closing a TLS Connection Two forms of TLS connection closure--graceful and abrupt--are supported. 4.13.3.1. Graceful Closure Either the client or server MAY terminate the TLS connection and - leave the LDAP connection intact by sending a TLS closure alert. + leave the LDAP connection intact by sending and receiving a TLS + closure alert. - Before sending a TLS closure alert, the client MUST either wait for - any outstanding LDAP operations to complete, or explicitly abandon - them. + The initiating protocol peer sends the TLS closure alert. If it + wishes to leave the LDAP connection intact, it then MUST cease to + send further PDUs and MUST ignore any received PDUs until it receives + a TLS closure alert from the other peer. - After the initiator of a close has sent a TLS closure alert, it MUST - discard any TLS messages until it has received a TLS closure alert - from the other party. It will cease to send TLS Record Protocol - PDUs, and following the receipt of the alert, MAY send and receive - LDAP PDUs. + Once the initiating protocol peer receives a TLS closure alert from + the other peer it MAY send and receive LDAP PDUs. - The other party, if it receives a TLS closure alert, MUST immediately - transmit a TLS closure alert. It will subsequently cease to send TLS - Record Protocol PDUs, and MAY send and receive LDAP PDUs. + When a protocol peer receives the initial TLS closure alert, it may + choose to allow the underlying LDAP connection intact. In this case, + it MUST immediately transmit a TLS closure alert. Following this, it + MAY send and receive LDAP PDUs. + + Protocol peers MAY drop the underlying LDAP connection after sending + or receiving a TLS closure alert. After the TLS connection has been closed, the server MUST NOT send responses to any request message received before the TLS closure. + Thus, clients wishing to receive responses to messages sent while the + TLS connection is intact MUST wait for those message responses before + sending the TLS closure alert. 4.13.3.2. Abrupt Closure -Sermersheim Internet-Draft - Expires Mar 2004 Page 32 - Lightweight Directory Access Protocol Version 3 - Either the client or server MAY abruptly close the TLS connection by dropping the underlying transfer protocol connection. In this circumstance, a server MAY send the client a Notice of Disconnection before dropping the underlying LDAP connection. +Sermersheim Internet-Draft - Expires Apr 2004 Page 32 + Lightweight Directory Access Protocol Version 3 + 5. Protocol Element Encodings and Transfer One underlying service is defined here. Clients and servers SHOULD implement the mapping of LDAP over [TCP] described in 5.2.1. 5.1. Protocol Encoding The protocol elements of LDAP are encoded for exchange using the - Basic Encoding Rules (BER) [X.690] of ASN.1 [X.680]. However, due to - the high overhead involved in using certain elements of the BER, the - following additional restrictions are placed on BER-encodings of LDAP - protocol elements: + Basic Encoding Rules [BER] of [ASN.1]. However, due to the high + overhead involved in using certain elements of the BER, the following + additional restrictions are placed on BER-encodings of LDAP protocol + elements: (1) Only the definite form of length encoding will be used. (2) OCTET STRING values will be encoded in the primitive form only. (3) If the value of a BOOLEAN type is true, the encoding MUST have its contents octets set to hex "FF". (4) If a value of a type is its default value, it MUST be absent. Only some BOOLEAN and INTEGER types have default values in this @@ -1833,25 +1826,25 @@ The encoded LDAPMessage PDUs are mapped directly onto the [TCP] bytestream using the BER-based encoding described in section 5.1. It is recommended that server implementations running over the TCP provide a protocol listener on the assigned port, 389. Servers may instead provide a listener on a different port number. Clients MUST support contacting servers on any valid TCP port. 6. Implementation Guidelines -Sermersheim Internet-Draft - Expires Mar 2004 Page 33 - Lightweight Directory Access Protocol Version 3 - 6.1. Server Implementations +Sermersheim Internet-Draft - Expires Apr 2004 Page 33 + Lightweight Directory Access Protocol Version 3 + The server MUST be capable of recognizing all the mandatory attribute types specified in [Models], and implement the syntaxes used by those attributes specified in [Syntaxes]. Servers MAY also recognize additional attribute type names. 6.2. Client Implementations Clients that follow referrals or search continuation references MUST ensure that they do not loop between servers. They MUST NOT repeatedly contact the same server for the same request with the same @@ -1863,446 +1856,394 @@ In the absence of prior agreements with servers, clients SHOULD NOT assume that servers support any particular schemas beyond those referenced in section 6.1. Different schemas can have different attribute types with the same names. The client can retrieve the subschema entries referenced by the subschemaSubentry attribute in the entries held by the server. 7. Security Considerations This version of the protocol provides facilities for simple - authentication using a cleartext password, as well as any SASL - mechanism [RFC2222]. SASL allows for integrity and privacy services - to be negotiated. + authentication using a cleartext password, as well as any [SASL] + mechanism. SASL allows for integrity and privacy services to be + negotiated. It is also permitted that the server can return its credentials to the client, if it chooses to do so. Use of cleartext password is strongly discouraged where the underlying transport service cannot guarantee confidentiality and may result in disclosure of the password to unauthorized parties. Requirements of authentication methods, SASL mechanisms, and TLS are described in [AUTHMETH]. When used with SASL, it should be noted that the name field of the BindRequest is not protected against modification. Thus if the distinguished name of the client (an LDAPDN) is agreed through the negotiation of the credentials, it takes precedence over any value in the unprotected name field. - Server implementors should plan for the possibility of an identity or + Server implementors should plan for the possibility of an identity associated with an LDAP connection being deleted, renamed, or modified, and take appropriate actions to prevent insecure side - -Sermersheim Internet-Draft - Expires Mar 2004 Page 34 - Lightweight Directory Access Protocol Version 3 - effects. The way in which this is dealt with is implementation specific. Likewise, server implementors should plan for the - possibility of an associated identities credentials becoming invalid. + possibility of an associated identity's credentials becoming invalid. + +Sermersheim Internet-Draft - Expires Apr 2004 Page 34 + Lightweight Directory Access Protocol Version 3 Implementations which cache attributes and entries obtained via LDAP MUST ensure that access controls are maintained if that information is to be provided to multiple clients, since servers may have access control policies which prevent the return of entries or attributes in search results except to particular authenticated clients. For example, caches could serve result information only to the client whose request caused it to be in the cache. Protocol servers may return referrals which redirect protocol clients to peer servers. It is possible for a rogue application to inject such referrals into the data stream in an attempt to redirect a client to a rogue server. Protocol clients are advised to be aware of this, and possibly reject referrals when confidentiality measures are - in place. Protocol clients are advised to ignore referrals from the - Start TLS operation. + not in place. Protocol clients are advised to ignore referrals from + the Start TLS operation. Protocol peers MUST be prepared to handle invalid and arbitrary length protocol encodings. A number of LDAP security advisories are available through [CERT]. 8. Acknowledgements This document is an update to RFC 2251, by Mark Wahl, Tim Howes, and Steve Kille. Their work along with the input of individuals of the IETF LDAPEXT, LDUP, LDAPBIS, and other Working Groups is gratefully acknowledged. 9. Normative References [X.500] ITU-T Rec. X.500, "The Directory: Overview of Concepts, Models and Service", 1993. - [Roadmap] K. Zeilenga (editor), "LDAP: Technical Specification Road - Map", draft-ietf-ldapbis-roadmap-xx.txt (a work in - progress). + [Roadmap] Zeilenga, K., "LDAP: Technical Specification Road Map", + draft-ietf-ldapbis-roadmap-xx.txt (a work in progress). - [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + [Keyword] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, March 1997. - [X.680] ITU-T Recommendation X.680 (07/2002) | ISO/IEC 8824-1:2002 + [ASN.1] ITU-T Recommendation X.680 (07/2002) | ISO/IEC 8824-1:2002 "Information Technology - Abstract Syntax Notation One (ASN.1): Specification of basic notation" - [X.690] ITU-T Rec. X.690 (07/2002) | ISO/IEC 8825-1:2002, + [BER] ITU-T Rec. X.690 (07/2002) | ISO/IEC 8825-1:2002, "Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)", 2002. -Sermersheim Internet-Draft - Expires Mar 2004 Page 35 - Lightweight Directory Access Protocol Version 3 + [LDAPIANA] Zeilenga, K., "IANA Considerations for LDAP", draft-ietf- + ldapbis-bcp64-00.txt, (a work in progress). - [LDAPIANA] K. Zeilenga, "IANA Considerations for LDAP", draft-ietf- - ldapbis-xx.txt (a work in progress). +Sermersheim Internet-Draft - Expires Apr 2004 Page 35 + Lightweight Directory Access Protocol Version 3 [ISO10646] Universal Multiple-Octet Coded Character Set (UCS) - Architecture and Basic Multilingual Plane, ISO/IEC 10646-1 : 1993. - [RFC2279] Yergeau, F., "UTF-8, a transformation format of Unicode - and ISO 10646", RFC 2279, January 1998. + [UTF-8] Yergeau, F., "UTF-8, a transformation format of Unicode + and ISO 10646", draft-yergeau-rfc2279bis-xx.txt, (a work + in progress). - [Models] K. Zeilenga, "LDAP: The Models", draft-ietf-ldapbis- - models-xx.txt (a work in progress). + [Models] Zeilenga, K., "LDAP: Directory Information Models", draft- + ietf-ldapbis-models-xx.txt (a work in progress). - [LDAPDN] K. Zeilenga (editor), "LDAP: String Representation of + [LDAPDN] Zeilenga, K., "LDAP: String Representation of Distinguished Names", draft-ietf-ldapbis-dn-xx.txt, (a work in progress). - [Syntaxes] K. Dally (editor), "LDAP: Syntaxes", draft-ietf-ldapbis- - syntaxes-xx.txt, (a work in progress). + [Syntaxes] Legg, S., and K. Dally, "LDAP: Syntaxes and Matching + Rules", draft-ietf-ldapbis-syntaxes-xx.txt, (a work in + progress). [X.501] ITU-T Rec. X.501, "The Directory: Models", 1993. [X.511] ITU-T Rec. X.511, "The Directory: Abstract Service Definition", 1993. - [RFC2396] Berners-Lee, T., Fielding, R., and L. Masinter Uniform + [URI] Berners-Lee, T., Fielding, R., and L. Masinter Uniform Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998. - [AuthMeth] R. Harrison (editor), "LDAP: Authentication Methods", - draft-ietf-ldapbis-authmeth-xx.txt, (a work in progress). + [AuthMeth] Harrison, R., "LDAP: Authentication Methods and Connection + Level Security Mechanisms ", draft-ietf-ldapbis-authmeth- + xx.txt, (a work in progress). - [RFC2222] Meyers, J., "Simple Authentication and Security Layer", + [SASL] Meyers, J., "Simple Authentication and Security Layer", RFC 2222, October 1997. [SASLPrep] Zeilenga, K., "Stringprep profile for user names and passwords", draft-ietf-sasl-saslprep-xx.txt, (a work in progress). [Unicode] The Unicode Consortium, "The Unicode Standard, Version 3.2.0" is defined by "The Unicode Standard, Version 3.0" (Reading, MA, Addison-Wesley, 2000. ISBN 0-201-61633-5), as amended by the "Unicode Standard Annex #27: Unicode 3.1" (http://www.unicode.org/reports/tr27/) and by the "Unicode Standard Annex #28: Unicode 3.2" (http://www.unicode.org/reports/tr28/). - [TCP] Postel, J., "Transmission Control Protocol", STD7, - September 1981 + [TCP] Postel, J., "Transmission Control Protocol", STD7 and RFC + 793, September 1981 - [IP] Postel, J., "Internet Protocol", STD5, September 1981 + [IP] Postel, J., "Internet Protocol", STD5 and RFC 791, + September 1981 -Sermersheim Internet-Draft - Expires Mar 2004 Page 36 +Sermersheim Internet-Draft - Expires Apr 2004 Page 36 Lightweight Directory Access Protocol Version 3 10. Informative References [CERT] the CERT(R) Center, (http://www.cert.org) 11. IANA Considerations It is requested that the Internet Assigned Numbers Authority (IANA) - update the occurrence of "RFC XXXX" Appendix B with this RFC number - at publication. + update the occurrence of "RFC XXXX" in Appendix B with this RFC + number at publication. 12. Editor's Address Jim Sermersheim Novell, Inc. 1800 South Novell Place Provo, Utah 84606, USA jimse@novell.com +1 801 861-3088 -Sermersheim Internet-Draft - Expires Mar 2004 Page 37 +Sermersheim Internet-Draft - Expires Apr 2004 Page 37 Lightweight Directory Access Protocol Version 3 Appendix A - LDAP Result Codes This normative appendix details additional considerations regarding LDAP result codes and provides a brief, general description of each LDAP result code enumerated in Section 4.1.10. - Additional result codes MAY be defined for use with extensions. - Client implementations SHALL treat any result code which they do not - recognize as an unknown error condition. + Additional result codes MAY be defined for use with extensions + [LDAPIANA]. Client implementations SHALL treat any result code which + they do not recognize as an unknown error condition. A.1 Non-Error Result Codes These result codes (called "non-error" result codes) do not indicate an error condition: success (0), compareTrue (6), compareFalse (7), referral (10), and saslBindInProgress (14). The success, compareTrue, and compare result codes indicate - successful completion (and, hence, are called to as "successful" + successful completion (and, hence, are referred to as "successful" result codes). The referral and saslBindInProgress result codes indicate the client is required to take additional action to complete the operation A.2 Result Codes Existing LDAP result codes are described as follows: success (0) - - Indicates successful completion of an operation. - - This result code is normally not returned by the compare - operation, see compareFalse and compareTrue. It is possible - that a future extension mechanism would allow this to be - returned by a compare operation. + Indicates the successful completion of an operation. operationsError (1) - Indicates that the operation is not properly sequenced with relation to other operations (of same or different type). For example, this code is returned if the client attempts to Start TLS [RFC2246] while there are other operations outstanding or if TLS was already established. protocolError (2) - -Sermersheim Internet-Draft - Expires Mar 2004 Page 38 - Lightweight Directory Access Protocol Version 3 - Indicates the server received data which has incorrect structure. - For bind operation only, the code may be resulted to indicate + For bind operation only, the code may be returned to indicate the server does not support the requested protocol version. timeLimitExceeded (3) - Indicates that the time limit specified by the client was exceeded before the operation could be completed. sizeLimitExceeded (4) +Sermersheim Internet-Draft - Expires Apr 2004 Page 38 + Lightweight Directory Access Protocol Version 3 + Indicates that the size limit specified by the client was exceeded before the operation could be completed. compareFalse (5) - - Indicates that the operation successfully completes and the - assertion has evaluated to FALSE. - - This result code is normally only returned by the compare - operation. + Indicates that the compare operation has successfully + completed and the assertion has evaluated to FALSE. compareTrue (6) - - Indicates that the operation successfully completes and the - assertion has evaluated to TRUE. - - This result code is normally only returned by the compare - operation. + Indicates that the compare operation has successfully + completed and the assertion has evaluated to TRUE. authMethodNotSupported (7) - Indicates that the authentication method or mechanism is not supported. strongAuthRequired (8) - Indicates that the server has detected that an established security association between the client and server has unexpectedly failed or been compromised, or that the server now requires the client to authenticate using a strong(er) mechanism. referral (10) - -Sermersheim Internet-Draft - Expires Mar 2004 Page 39 - Lightweight Directory Access Protocol Version 3 - Indicates that a referral needs to be chased to complete the operation (see section 4.1.11). adminLimitExceeded (11) - Indicates that an administrative limit has been exceeded. unavailableCriticalExtension (12) - Indicates that server cannot perform a critical extension (see section 4.1.12). confidentialityRequired (13) - Indicates that data confidentiality protections are required. saslBindInProgress (14) - Indicates the server requires the client to send a new bind request, with the same SASL mechanism, to continue the authentication process (see section 4.2). noSuchAttribute (16) - Indicates that the named entry does not contain the specified attribute or attribute value. undefinedAttributeType (17) - Indicates that a request field contains an undefined attribute type. inappropriateMatching (18) - - Indicates that a request cannot be completed due to an - inappropriate matching. + Indicates that an attempt was made, e.g. in a filter, to use + a matching rule not defined for the attribute type concerned. constraintViolation (19) - Indicates that the client supplied an attribute value which - does not conform to constraints placed upon it by the data - model. +Sermersheim Internet-Draft - Expires Apr 2004 Page 39 + Lightweight Directory Access Protocol Version 3 - For example, this code is returned when the multiple values - are supplied to an attribute which has a SINGLE-VALUE - constraint. + Indicates that the client supplied an attribute value which + does not conform to the constraints placed upon it by the + data model. -Sermersheim Internet-Draft - Expires Mar 2004 Page 40 - Lightweight Directory Access Protocol Version 3 + For example, this code is returned when multiple values are + supplied to an attribute which has a SINGLE-VALUE constraint. attributeOrValueExists (20) - Indicates that the client supplied an attribute or value to - be added to an entry already exists. + be added to an entry, but the attribute or value already + exists. invalidAttributeSyntax (21) - Indicates that a purported attribute value does not conform to the syntax of the attribute. noSuchObject (32) - Indicates that the object does not exist in the DIT. aliasProblem (33) - Indicates that an alias problem has occurred. Typically an alias has been dereferenced which names no object. invalidDNSyntax (34) - - Indicates that a LDAPDN or RelativeLDAPDN field (e.g. search + Indicates that an LDAPDN or RelativeLDAPDN field (e.g. search base, target entry, ModifyDN newrdn, etc.) of a request does not conform to the required syntax or contains attribute values which do not conform to the syntax of the attribute's type. aliasDereferencingProblem (36) - Indicates that a problem occurred while dereferencing an alias. Typically an alias was encountered in a situation where it was not allowed or where access was denied. inappropriateAuthentication (48) - Indicates the server requires the client which had attempted to bind anonymously or without supplying credentials to - provide some form of credentials, + provide some form of credentials. invalidCredentials (49) - Indicates the supplied password or SASL credentials are invalid. -Sermersheim Internet-Draft - Expires Mar 2004 Page 41 - Lightweight Directory Access Protocol Version 3 - insufficientAccessRights (50) - Indicates that the client does not have sufficient access rights to perform the operation. busy (51) - Indicates that the server is busy. unavailable (52) - Indicates that the server is shutting down or a subsystem necessary to complete the operation is offline. - unwillingToPerform (53) +Sermersheim Internet-Draft - Expires Apr 2004 Page 40 + Lightweight Directory Access Protocol Version 3 + unwillingToPerform (53) Indicates that the server is unwilling to perform the operation. loopDetect (54) - Indicates that the server has detected an internal loop. namingViolation (64) - Indicates that the entry name violates naming restrictions. objectClassViolation (65) - Indicates that the entry violates object class restrictions. notAllowedOnNonLeaf (66) - - Indicates that operation is inappropriately acting upon a + Indicates that the operation is inappropriately acting upon a non-leaf entry. notAllowedOnRDN (67) - Indicates that the operation is inappropriately attempting to remove a value which forms the entry's relative distinguished name. entryAlreadyExists (68) - - Indicates that the request cannot be added fulfilled as the - entry already exists. - -Sermersheim Internet-Draft - Expires Mar 2004 Page 42 - Lightweight Directory Access Protocol Version 3 + Indicates that the request cannot be fulfilled (added, moved, + or renamed) as the target entry already exists. objectClassModsProhibited (69) - Indicates that the attempt to modify the object class(es) of - an entry objectClass attribute is prohibited. + an entry's objectClass attribute is prohibited. - For example, this code is returned when a when a client - attempts to modify the structural object class of an entry. + For example, this code is returned when a client attempts to + modify the structural object class of an entry. affectsMultipleDSAs (71) - Indicates that the operation cannot be completed as it affects multiple servers (DSAs). other (80) - Indicates the server has encountered an internal error. -Sermersheim Internet-Draft - Expires Mar 2004 Page 43 +Sermersheim Internet-Draft - Expires Apr 2004 Page 41 Lightweight Directory Access Protocol Version 3 Appendix B - Complete ASN.1 Definition This appendix is normative. Lightweight-Directory-Access-Protocol-V3 -- Copyright (C) The Internet Society (2003). This version of -- this ASN.1 module is part of RFC XXXX; see the RFC itself -- for full legal notices. @@ -2338,48 +2279,45 @@ ... }, controls [0] Controls OPTIONAL } MessageID ::= INTEGER (0 .. maxInt) maxInt INTEGER ::= 2147483647 -- (2^^31 - 1) -- LDAPString ::= OCTET STRING -- UTF-8 encoded, -- [ISO10646] characters - LDAPOID ::= OCTET STRING -- Constrained to numericoid [Models] + LDAPOID ::= OCTET STRING -- Constrained to [Models] LDAPDN ::= LDAPString RelativeLDAPDN ::= LDAPString AttributeDescription ::= LDAPString -Sermersheim Internet-Draft - Expires Mar 2004 Page 44 +Sermersheim Internet-Draft - Expires Apr 2004 Page 42 Lightweight Directory Access Protocol Version 3 - -- Constrained to attributedescription + -- Constrained to -- [Models] - AttributeSelection ::= SEQUENCE OF - LDAPString - AttributeValue ::= OCTET STRING AttributeValueAssertion ::= SEQUENCE { attributeDesc AttributeDescription, assertionValue AssertionValue } AssertionValue ::= OCTET STRING Attribute ::= SEQUENCE { type AttributeDescription, - vals SET OF AttributeValue } + vals SET SIZE (1..MAX) OF value AttributeValue } MatchingRuleId ::= LDAPString LDAPResult ::= SEQUENCE { resultCode ENUMERATED { success (0), operationsError (1), protocolError (2), timeLimitExceeded (3), sizeLimitExceeded (4), @@ -2403,50 +2341,50 @@ noSuchObject (32), aliasProblem (33), invalidDNSyntax (34), -- 35 reserved for undefined isLeaf -- aliasDereferencingProblem (36), -- 37-47 unused -- inappropriateAuthentication (48), invalidCredentials (49), insufficientAccessRights (50), busy (51), - -Sermersheim Internet-Draft - Expires Mar 2004 Page 45 - Lightweight Directory Access Protocol Version 3 - unavailable (52), unwillingToPerform (53), loopDetect (54), + +Sermersheim Internet-Draft - Expires Apr 2004 Page 43 + Lightweight Directory Access Protocol Version 3 + -- 55-63 unused -- namingViolation (64), objectClassViolation (65), notAllowedOnNonLeaf (66), notAllowedOnRDN (67), entryAlreadyExists (68), objectClassModsProhibited (69), -- 70 reserved for CLDAP -- affectsMultipleDSAs (71), -- 72-79 unused -- other (80), ... }, -- 81-90 reserved for APIs -- matchedDN LDAPDN, diagnosticMessage LDAPString, referral [3] Referral OPTIONAL } - Referral ::= SEQUENCE OF URL + Referral ::= SEQUENCE SIZE (1..MAX) OF uri URI - URL ::= LDAPString -- limited to characters permitted in - -- URLs + URI ::= LDAPString -- limited to characters permitted in + -- URIs - Controls ::= SEQUENCE OF Control + Controls ::= SEQUENCE OF control Control Control ::= SEQUENCE { controlType LDAPOID, criticality BOOLEAN DEFAULT FALSE, controlValue OCTET STRING OPTIONAL } BindRequest ::= [APPLICATION 0] SEQUENCE { version INTEGER (1 .. 127), name LDAPDN, authentication AuthenticationChoice } @@ -2461,100 +2399,105 @@ mechanism LDAPString, credentials OCTET STRING OPTIONAL } BindResponse ::= [APPLICATION 1] SEQUENCE { COMPONENTS OF LDAPResult, serverSaslCreds [7] OCTET STRING OPTIONAL } UnbindRequest ::= [APPLICATION 2] NULL SearchRequest ::= [APPLICATION 3] SEQUENCE { - -Sermersheim Internet-Draft - Expires Mar 2004 Page 46 - Lightweight Directory Access Protocol Version 3 - baseObject LDAPDN, scope ENUMERATED { baseObject (0), + +Sermersheim Internet-Draft - Expires Apr 2004 Page 44 + Lightweight Directory Access Protocol Version 3 + singleLevel (1), wholeSubtree (2) }, derefAliases ENUMERATED { neverDerefAliases (0), derefInSearching (1), derefFindingBaseObj (2), derefAlways (3) }, sizeLimit INTEGER (0 .. maxInt), timeLimit INTEGER (0 .. maxInt), typesOnly BOOLEAN, filter Filter, attributes AttributeSelection } + AttributeSelection ::= SEQUENCE OF selection LDAPString + Filter ::= CHOICE { - and [0] SET SIZE (1..MAX) OF Filter, - or [1] SET SIZE (1..MAX) OF Filter, + and [0] SET SIZE (1..MAX) OF filter Filter, + or [1] SET SIZE (1..MAX) OF filter Filter, not [2] Filter, equalityMatch [3] AttributeValueAssertion, substrings [4] SubstringFilter, greaterOrEqual [5] AttributeValueAssertion, lessOrEqual [6] AttributeValueAssertion, present [7] AttributeDescription, approxMatch [8] AttributeValueAssertion, extensibleMatch [9] MatchingRuleAssertion } SubstringFilter ::= SEQUENCE { type AttributeDescription, -- at least one must be present, -- initial and final can occur at most once - substrings SEQUENCE OF CHOICE { + substrings SEQUENCE SIZE (1..MAX) OF substring CHOICE { initial [0] AssertionValue, any [1] AssertionValue, final [2] AssertionValue } } MatchingRuleAssertion ::= SEQUENCE { matchingRule [1] MatchingRuleId OPTIONAL, type [2] AttributeDescription OPTIONAL, matchValue [3] AssertionValue, dnAttributes [4] BOOLEAN DEFAULT FALSE } SearchResultEntry ::= [APPLICATION 4] SEQUENCE { objectName LDAPDN, attributes PartialAttributeList } - PartialAttributeList ::= SEQUENCE OF SEQUENCE { - type AttributeDescription, - vals SET OF AttributeValue } + PartialAttributeList ::= SEQUENCE OF + attribute PartialAttribute - SearchResultReference ::= [APPLICATION 19] SEQUENCE OF URL + PartialAttribute ::= SEQUENCE { + type AttributeDescription, + vals SET OF value AttributeValue } - SearchResultDone ::= [APPLICATION 5] LDAPResult + SearchResultReference ::= [APPLICATION 19] SEQUENCE -Sermersheim Internet-Draft - Expires Mar 2004 Page 47 +Sermersheim Internet-Draft - Expires Apr 2004 Page 45 Lightweight Directory Access Protocol Version 3 + SIZE (1..MAX) OF uri URI + + SearchResultDone ::= [APPLICATION 5] LDAPResult + ModifyRequest ::= [APPLICATION 6] SEQUENCE { object LDAPDN, - changes SEQUENCE OF SEQUENCE { + changes SEQUENCE OF change SEQUENCE { operation ENUMERATED { add (0), delete (1), replace (2) }, - modification Attribute } } + modification PartialAttribute } } ModifyResponse ::= [APPLICATION 7] LDAPResult AddRequest ::= [APPLICATION 8] SEQUENCE { entry LDAPDN, attributes AttributeList } - AttributeList ::= SEQUENCE OF SEQUENCE { - type AttributeDescription, - vals SET OF AttributeValue } + AttributeList ::= SEQUENCE OF attribute Attribute AddResponse ::= [APPLICATION 9] LDAPResult DelRequest ::= [APPLICATION 10] LDAPDN DelResponse ::= [APPLICATION 11] LDAPResult ModifyDNRequest ::= [APPLICATION 12] SEQUENCE { entry LDAPDN, newrdn RelativeLDAPDN, @@ -2575,21 +2518,21 @@ requestName [0] LDAPOID, requestValue [1] OCTET STRING OPTIONAL } ExtendedResponse ::= [APPLICATION 24] SEQUENCE { COMPONENTS OF LDAPResult, responseName [10] LDAPOID OPTIONAL, responseValue [11] OCTET STRING OPTIONAL } END -Sermersheim Internet-Draft - Expires Mar 2004 Page 48 +Sermersheim Internet-Draft - Expires Apr 2004 Page 46 Lightweight Directory Access Protocol Version 3 Appendix C - Change History C.1 Changes made to RFC 2251: C.1.1 Editorial @@ -2632,21 +2575,21 @@ the transfer encoding is present in attributeDesc, the AssertionValue is encoded as specified by the option...". Previously, only the ;binary option was mentioned. C.2.3 Sections 4.2, 4.9, 4.10 - Added alias dereferencing specifications. In the case of modDN, followed precedent set on other update operations (... alias is not dereferenced...) In the case of bind and compare stated that -Sermersheim Internet-Draft - Expires Mar 2004 Page 49 +Sermersheim Internet-Draft - Expires Apr 2004 Page 47 Lightweight Directory Access Protocol Version 3 servers SHOULD NOT dereference aliases. Specifications were added because they were missing from the previous version and caused interoperability problems. Concessions were made for bind and compare (neither should have ever allowed alias dereferencing) by using SHOULD NOT language, due to the behavior of some existing implementations. C.2.4 Sections 4.5 and Appendix A @@ -2688,21 +2631,21 @@ by a lower layer" to "the underlying transport service cannot guarantee confidentiality" C.3.6 Section 4.5.2 - Removed all mention of ExtendedResponse due to lack of implementation. C.4 Changes made to draft-ietf-ldapbis-protocol-02.txt: -Sermersheim Internet-Draft - Expires Mar 2004 Page 50 +Sermersheim Internet-Draft - Expires Apr 2004 Page 48 Lightweight Directory Access Protocol Version 3 C.4.1 Section 4 - Removed "typically" from "and is typically transferred" in the first paragraph. We know of no (and can conceive of no) case where this isn't true. - Added "Section 5.1 specifies how the LDAP protocol is encoded." To the first paragraph. Added this cross reference for readability. - Changed "version 3 " to "version 3 or later" in the second @@ -2744,21 +2687,21 @@ controls). C.4.6 Section 4.4 - Changed "One unsolicited notification is defined" to "One unsolicited notification (Notice of Disconnection) is defined" in the third paragraph. For clarity and readability. C.4.7 Section 4.5.1 -Sermersheim Internet-Draft - Expires Mar 2004 Page 51 +Sermersheim Internet-Draft - Expires Apr 2004 Page 49 Lightweight Directory Access Protocol Version 3 - Changed "checking for the existence of the objectClass attribute" to "checking for the presence of the objectClass attribute" in the last paragraph. This was done as a measure of consistency (we use the terms present and presence rather than exists and existence in search filters). C.4.8 Section 4.5.3 @@ -2800,21 +2743,21 @@ whether there can be more than one value of an attribute of that type in an entry, the syntax to which the values must conform, the kinds of matching which can be performed on values of that attribute, and other functions." to " An attribute is a description (a type and zero or more options) with one or more associated values. The attribute type governs whether the attribute can have multiple values, the syntax and matching rules used to construct and compare values of that attribute, and other functions. Options indicate modes of transfer and other -Sermersheim Internet-Draft - Expires Mar 2004 Page 52 +Sermersheim Internet-Draft - Expires Apr 2004 Page 50 Lightweight Directory Access Protocol Version 3 functions.". This points out that an attribute consists of both the type and options. C.5.2 Section 4 - Changed "Section 5.1 specifies the encoding rules for the LDAP protocol" to "Section 5.1 specifies how the protocol is encoded and transferred." @@ -2857,21 +2800,21 @@ - Changed the wording regarding 'equally capable' referrals to "If multiple URLs are present, the client assumes that any URL may be used to progress the operation.". The previous language implied that the server MUST enforce rules that it was practically incapable of. The new language highlights the original intent-- that is, that any of the referrals may be used to progress the operation, there is no inherent 'weighting' mechanism. C.5.7 Section 4.5.1 and Appendix A -Sermersheim Internet-Draft - Expires Mar 2004 Page 53 +Sermersheim Internet-Draft - Expires Apr 2004 Page 51 Lightweight Directory Access Protocol Version 3 - Added the comment "-- initial and final can occur at most once", to clarify this restriction. C.5.8 Section 5.1 - Changed heading from "Mapping Onto BER-based Transport Services" to "Protocol Encoding". @@ -2913,21 +2856,21 @@ doc now specifies a difference between transfer and tagging options and describes the semantics of each, and how and when subtyping rules apply. Now allow options to be transmitted in any order but disallow any ordering semantics to be implied. These changes are the result of ongoing input from an engineering team designed to deal with ambiguity issues surrounding attribute options. C.7.3 Sections 4.1.5.1 and 4.1.6 -Sermersheim Internet-Draft - Expires Mar 2004 Page 54 +Sermersheim Internet-Draft - Expires Apr 2004 Page 52 Lightweight Directory Access Protocol Version 3 - Refer to non "binary" transfer encodings as "native encoding" rather than "string" encoding to clarify and avoid confusion. C.8 Changes made to draft-ietf-ldapbis-protocol-06.txt: C.8.1 Title - Changed to "LDAP: The Protocol" to be consisted with other working @@ -2969,21 +2912,21 @@ C.8.7 Relationship to X.500 - Removed section. It has been moved to [Roadmap] C.8.8 Server Specific Data Requirements - Removed section. It has been moved to [Models] C.8.9 Elements of Protocol -Sermersheim Internet-Draft - Expires Mar 2004 Page 55 +Sermersheim Internet-Draft - Expires Apr 2004 Page 53 Lightweight Directory Access Protocol Version 3 - Added "Section 5.1 specifies how the protocol is encoded and transferred." to the end of the first paragraph for reference. - Reworded notes about extensibility, and now talk about implied extensibility and the use of ellipses in the ASN.1 - Removed references to LDAPv2 in third and fourth paragraphs. @@ -3026,21 +2969,21 @@ - Clarified intent regarding exactly what is to be BER encoded. - Clarified that clients must not expect ;binary when not asking for it (;binary, as opposed to ber encoded data). C.8.17 Attribute - Use the term "attribute description" in lieu of "type" -Sermersheim Internet-Draft - Expires Mar 2004 Page 56 +Sermersheim Internet-Draft - Expires Apr 2004 Page 54 Lightweight Directory Access Protocol Version 3 - Clarified the fact that clients cannot rely on any apparent ordering of attribute values. C.8.18 LDAPResult - To resultCode, added ellipses "..." to the enumeration to indicate extensibility. and added a note, pointing to [LDAPIANA] @@ -3083,21 +3026,21 @@ - Added as normative appendix A C.8.25 ASN.1 - Added EXTENSIBILITY IMPLIED - Added a number of comments holding referenced to [Models] and [ISO10646]. -Sermersheim Internet-Draft - Expires Mar 2004 Page 57 +Sermersheim Internet-Draft - Expires Apr 2004 Page 55 Lightweight Directory Access Protocol Version 3 - Removed AttributeType. It is not used. C.9 Changes made to draft-ietf-ldapbis-protocol-07.txt: - Removed all mention of transfer encodings and the binary attribute option. Please refer to draft-legg-ldap-binary-00.txt and draft- legg-ldap-transfer-00.txt @@ -3137,21 +3080,21 @@ C.11 Changes made to draft-ietf-ldapbis-protocol-09.txt: - Fixed formatting C.12 Changes made to draft-ietf-ldapbis-protocol-10.txt: C.12.1 Section 4.1.4: - Removed second paragraph as this language exists in MODELS -Sermersheim Internet-Draft - Expires Mar 2004 Page 58 +Sermersheim Internet-Draft - Expires Apr 2004 Page 56 Lightweight Directory Access Protocol Version 3 C.12.2 Section 4.2.1: - Replaced fourth paragraph. It was accidentally removed in an earlier edit. C.12.2 Section 4.13: - Added section describing the StartTLS operation (moved from @@ -3192,21 +3135,21 @@ C.15 Changes made to draft-ietf-ldapbis-protocol-13.txt C.15.1 Section 2 & various - Added definitions for LDAP connection, TLS connection, and LDAP association, and updated appropriate fields to use proper terms. C.15.2 Section 4.2 - Added text to authentication, specifying the way in which textual strings used as passwords are to be prepared. -Sermersheim Internet-Draft - Expires Mar 2004 Page 59 +Sermersheim Internet-Draft - Expires Apr 2004 Page 57 Lightweight Directory Access Protocol Version 3 C.15.3 Section 4.5.1 - Clarified derefInSearching. Specifically how it works in terms of subtree and one level searches C.15.4 Section 4.5.2 - Changed MUST to SHOULD for returning textual attribute name, The MUST is unreasonable. There are likely cases (such as when the @@ -3249,21 +3192,21 @@ negotiations of a particular mechanism, the mechanism technical specification should detail how applications are to deal with them. LDAP should not require any special handling. And if an LDAP client had used such a mechanism, it would have the option of using another mechanism. C.16.3 Section 4.5.2 and Section 7 - Removed: "If the LDAP association is operating over a connection- oriented transport such as TCP" -Sermersheim Internet-Draft - Expires Mar 2004 Page 60 +Sermersheim Internet-Draft - Expires Apr 2004 Page 58 Lightweight Directory Access Protocol Version 3 This is always true. C.16.4 Section 4.11 - Added: thus a client SHOULD NOT use the Abandon operation when it needs an indication of whether the operation was abandoned. For example, if a client performs an update operation (Add, Modify, or ModifyDN), and it needs to know whether the directory has changed due to the operation, it should not use the Abandon operation to @@ -3306,21 +3249,21 @@ C.16.6 Section 4.13.3.1 - Added: After the TLS connection has been closed, the server MUST NOT send responses to any request message received before the TLS closure. C.16.7 Section A2 - Removed precedence rules -Sermersheim Internet-Draft - Expires Mar 2004 Page 61 +Sermersheim Internet-Draft - Expires Apr 2004 Page 59 Lightweight Directory Access Protocol Version 3 C.17 Changes made to draft-ietf-ldapbis-protocol-15.txt C.17.1 Section 4.1.8 - Removed: "Servers which support matching rules for use in the extensibleMatch search filter MUST list the matching rules they implement in subschema entries, using the matchingRules attributes. The server SHOULD also list there, using the matchingRuleUse attribute, the attribute types with which each @@ -3363,21 +3306,21 @@ C.18.3 Section 4.2.1 - Further clarified the authentication state of an abandoned bind C.18.4 Section 4.5.1 - Added: "Note that the AssertionValue in a substrings filter item MUST conform to the assertion syntax of the EQUALITY matching rule for the attribute type rather than the assertion syntax of the SUBSTR matching rule for the attribute type. The entire -Sermersheim Internet-Draft - Expires Mar 2004 Page 62 +Sermersheim Internet-Draft - Expires Apr 2004 Page 60 Lightweight Directory Access Protocol Version 3 SubstringFilter is converted into an assertion value of the substrings matching rule prior to applying the rule." C.18.5 Section 4.6 - Replaced AttributeTypeAndValues with Attribute as they are equivalent. - Reformatted documentation of the various fields. @@ -3400,38 +3343,69 @@ C.18.8 Section 11 - Added IANA considerations C.18.9 Section A.2 - Clarified that strongAuthRequired could be sent any time (including when credentials have been weakened or compromised. C.18.10 Appendix B - Added copyright to ASN.1 definition -Appendix D - Outstanding Work Items +C.19 Changes made to draft-ietf-ldapbis-protocol-17.txt -D.1 General - - Reconcile problems with [Models]. Section 3.2 was wholly removed. - There were some protocol semantics in that section that need to be - brought back. Specifically, there was the notion of the server - implicitly adding objectClass superclasses when a value is added. +C.19.1 Section 4.1.1 + - Changed MAY to SHOULD when stating when a Notice of Disconnect is + to be returned. -D.2 Verify references. +C.19.2 Sections 4.1.10 and 4.5.3 + - Changed occurrences of URL to URI for format of referrals. - - Many referenced documents have changed. Ensure references and - section numbers are correct. +C.19.3 Section 4.1.11 + - Dropped MUST imperative in paragraph 2, and added a SHOULD in + paragraph 3 to align with [Keywords]. -D.3 Review 2119 usage +C.19.4 Section 4.2 + - Reworded section on string prep for simple passwords for clarity. -D.4 Reconcile with I-D Nits +C.19.5 Section 4.2.1 + - Dropped MUST imperative in paragraph 3 to align with [Keywords]. -Sermersheim Internet-Draft - Expires Mar 2004 Page 63 +Sermersheim Internet-Draft - Expires Apr 2004 Page 61 + Lightweight Directory Access Protocol Version 3 + +C.19.6 Section 4.2.2 + - Added SHALL NOT imperative to last paragraph to align with + [Keywords]. + +C.19.7 Section 4.5.1 + - Added correct approxMatch semantics. + +C.19.8 Various + - Added SHALL NOT imperative in regards to dereferencing aliases of + base objects. + +C.19.9 Section 4.9 + - Allow modDN to fail when moving between naming contexts. + +C.19.10 Section 4.12 + - Added RECOMMENDED imperative to paragraph that talks about + advertising supported extended operations. + +C.19.11 Section 4.1.11 + - Dropped all MAY imperative to align with [Keywords]. + +C.19.12 Various + - Made it more obvious that Attribute contains at least one value, + while PartialAttribute now allows zero values. Added appropriate + references back to Attribute and PartialAttribute. + +Sermersheim Internet-Draft - Expires Apr 2004 Page 62 Lightweight Directory Access Protocol Version 3 Full Copyright Statement Copyright (C) The Internet Society (2003). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any @@ -3448,11 +3422,11 @@ The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS 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. -Sermersheim Internet-Draft - Expires Mar 2004 Page 64 +Sermersheim Internet-Draft - Expires Apr 2004 Page 63