wdiff draft-ietf-ldapbis-protocol-06.txt draft-ietf-ldapbis-protocol-07.txt

Internet-Draft Editor: J. Sermersheim
Intended Category: Standard Track Novell, Inc
Document: draft-ietf-ldapbis-protocol-06.txt January draft-ietf-ldapbis-protocol-07.txt March 2002
Obsoletes: RFC 2251

Lightweight Directory Access

LDAP: The Protocol (v3)

Status of this Memo

This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of [RFC2026]. RFC2026.

Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that other
groups may also distribute working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."

The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt

The list of Internet-Draft Shadow Directories can be accessed at
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 <ietf-ldapbis@openldap.org>. Please send
editorial comments directly to the editor <jimse@novell.com>.

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).

Table of Contents

1. Status of this Memo..............................................1 Introduction.....................................................2
2. Abstract.........................................................2 Conventions......................................................3
3. Models...........................................................3
3.1. Protocol Model.................................................3
3.2. Data Model.....................................................4
3.2.1. Attributes of Entries........................................4
3.2.2. Subschema Entries and Subentries.............................6
3.3. Relationship to X.500..........................................7
3.4. Server-specific Data Requirements..............................7 Model...................................................3
4. Elements of Protocol.............................................8 Protocol.............................................3
4.1. Common Elements................................................8 Elements................................................4
4.1.1. Message Envelope.............................................8 Envelope.............................................4
4.1.1.1. Message ID.................................................9 ID.................................................5
4.1.2. String Types.................................................9
4.1.3. Distinguished Name and Relative Distinguished Name..........10
4.1.4. Attribute Type..............................................10
4.1.5. Attribute Description.......................................11
4.1.5.1. Binary Option.............................................13
4.1.6. Attribute Value.............................................13 Types.................................................6

Sermersheim Internet-Draft - Expires July Sep 2002 Page 1
Lightweight Directory Access Protocol Version 3

4.1.3. Distinguished Name and Relative Distinguished Name...........6
4.1.5. Attribute Description........................................6
4.1.5.1. Binary Transfer Option.....................................7
4.1.6. Attribute Value..............................................8
4.1.7. Attribute Value Assertion...................................14 Assertion....................................8
4.1.8. Attribute...................................................14 Attribute....................................................9
4.1.9. Matching Rule Identifier....................................15 Identifier.....................................9
4.1.10. Result Message.............................................15 Message.............................................10
4.1.11. Referral...................................................17 Referral...................................................11
4.1.12. Controls...................................................18 Controls...................................................12
4.2. Bind Operation................................................19 Operation................................................13
4.2.1. Sequencing of the Bind Request..............................20
4.2.2. Authentication and Other Security Services..................21 Request..............................14
4.2.3. Bind Response...............................................21 Response...............................................15
4.3. Unbind Operation..............................................22 Operation..............................................16
4.4. Unsolicited Notification......................................22 Notification......................................16
4.4.1. Notice of Disconnection.....................................23 Disconnection.....................................17
4.5. Search Operation..............................................23 Operation..............................................17
4.5.1. Search Request..............................................24 Request..............................................17
4.5.2. Search Result...............................................27 Result...............................................21
4.5.3. Continuation References in the Search Result................28 Result................22
4.6. Modify Operation..............................................30 Operation..............................................24
4.7. Add Operation.................................................31 Operation.................................................25
4.8. Delete Operation..............................................32 Operation..............................................26
4.9. Modify DN Operation...........................................33 Operation...........................................27
4.10. Compare Operation............................................34 Operation............................................28
4.11. Abandon Operation............................................35 Operation............................................29
4.12. Extended Operation...........................................35 Operation...........................................29
5. Protocol Element Encodings and Transfer.........................36 Transfer.........................30
5.1. Protocol Encoding.............................................36 Encoding.............................................30
5.2. Transfer Protocols............................................36 Protocols............................................30
5.2.1. Transmission Control Protocol (TCP).........................36 (TCP).........................31
6. Implementation Guidelines.......................................37 Guidelines.......................................31
6.1. Server Implementations........................................37 Implementations........................................31
6.2. Client Implementations........................................37 Implementations........................................31
7. Security Considerations.........................................37 Considerations.........................................31
8. Acknowledgements................................................38 Acknowledgements................................................32
9. Bibliography....................................................38 Normative References............................................32
10. Editor's Address...............................................39 Address...............................................33
Appendix A - Complete ASN.1 Definition.............................40 LDAP Result Codes.....................................34
A.1 Non-Error Result Codes.........................................34
A.2 Error Result Codes.............................................34
A.3 Classes and Precedence of Error Result Codes...................34
Appendix B C - Change History........................................45
B.1
C.1 Changes made to RFC 2251:......................................45
B.2
C.2 Changes made to draft-ietf-ldapbis-protocol-00.txt:............45
B.3
C.3 Changes made to draft-ietf-ldapbis-protocol-01.txt:............46
B.4
C.4 Changes made to draft-ietf-ldapbis-protocol-02.txt:............46
B.5
C.5 Changes made to draft-ietf-ldapbis-protocol-03.txt:............48
B.6
C.6 Changes made to draft-ietf-ldapbis-protocol-04.txt:............50
B.7
C.7 Changes made to draft-ietf-ldapbis-protocol-05.txt:............50
Appendix C D - Outstanding Work Items................................50

2. Abstract

The protocol described in this document is designed to provide access
to directories supporting the [X.500] models, while not incurring the
resource requirements of the X.500 Directory Access Protocol (DAP).
This protocol is specifically targeted at management applications and
browser applications that provide read/write interactive access to Items................................54

1. Introduction

Sermersheim Internet-Draft - Expires July Sep 2002 Page 2
Lightweight Directory Access Protocol Version 3

directories. When used with a directory supporting the X.500
protocols, it

The Directory is intended "a collection of open systems cooperating to provide
directory services" [X.500]. A Directory user, which may be a complement to human
or other entity, accesses the X.500 DAP. Directory through a client (or
Directory User Agent (DUA)). 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].

Key aspects of this version client, on behalf of LDAP are:

- All 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 LDAPv2 [RFC1777] are supported. The
protocol is carried directly over TCP or other transport,
bypassing much of Lightweight Directory
Access Protocol, along with their semantic meanings. Following the session/presentation overhead
description of X.500 DAP.

- Most protocol data elements can be encoded as ordinary strings
(e.g., Distinguished Names).

- Referrals to other servers may be returned.

- SASL mechanisms may be used with LDAP to provide association
security services.

- Attribute values and Distinguished Names have been
internationalized through elements, it describes the use of way in which the ISO 10646 character set.

- The
protocol can be extended to support new operations, is encoded and
controls may be used to extend existing operations.

- Schema transferred.

This document is published in an integral part of the directory LDAP Technical Specification
[Roadmap].

This document replaces RFC 2251. Appendix C holds a detailed log of
changes to RFC 2251. At publication time, this appendix will be used by clients.

3. Models

Interest in X.500 directory technologies in the Internet has led to
efforts
distilled to reduce the high cost of entry associated with use a summary of these
technologies. This 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 continues the efforts
are to define directory
protocol alternatives, updating the LDAPv2 protocol specification.

3.1. be interpreted as described in [RFC2119].

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
operation(s), the server returns a response containing any results or
errors to the requesting client.

In keeping with the goal of easing the costs associated with use of
the directory, it is an objective of this protocol to minimize the
complexity of clients so as to facilitate widespread deployment of
applications capable of using the directory.

Note that 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.

Sermersheim Internet-Draft - Expires July 2002 Page 3
Lightweight Directory Access Protocol Version 3
Requests and responses for multiple operations may be exchanged
between a client and server in any order, provided the client
eventually receives a response for every request that requires one.

In LDAP versions 1 and 2, no provision was made for

Note that the core protocol servers
returning referrals to clients. However, for improved performance and
distribution, operations defined in this version of the protocol permits servers to return
to clients, referrals to other servers. This allows servers to
offload the work of contacting other servers to progress operations.

Note that the core protocol operations defined in this document can
be mapped to a strict subset document can
be mapped to a strict subset of the X.500(1997) directory abstract
service, so it can be cleanly provided by the DAP.
service. However there is not a one-to-one mapping between LDAP
protocol operations and DAP
operations: server operations. Server implementations
acting as a gateway to X.500 directories may need to make multiple
DAP requests.

3.2. Data Model

This section provides a brief introduction to the X.500 data model,
as used by LDAP.

4. Elements of Protocol

Sermersheim Internet-Draft - Expires Sep 2002 Page 3
Lightweight Directory Access Protocol Version 3

The LDAP protocol assumes there are one or more servers which jointly
provide access to a Directory Information Tree (DIT). The tree is
made up of entries. Entries have names: one or more attribute values
from the entry form its relative distinguished name (RDN), which MUST
be unique among all its siblings. The concatenation of the relative
distinguished names of the sequence of entries from described using Abstract Syntax Notation 1
(ASN.1) [X.680], and is transferred using a particular
entry to an immediate subordinate of the root subset of ASN.1 Basic
Encoding Rules [X.690]. Section 5.1 specifies how the tree forms that
entry's Distinguished Name (DN), which protocol is unique
encoded and transferred.

In order to support future extensions to this protocol, extensibility
is implied where it is allowed (per ASN.1). In addition, ellipses
(...) have been supplied in the tree. An
example of a Distinguished Name is:

CN=Steve Kille, O=Isode Limited, C=GB

Some servers may hold cache or shadow copies ASN.1 types that are explicitly
extensible as discussed in [LDAPIANA]. Because of entries, which can be
used to answer search the implied
extensibility, clients and comparison queries, but will return
referrals or contact other servers if modification operations are
requested.

Servers that perform caching or shadowing MUST ensure that ignore trailing SEQUENCE
elements whose tags they do not violate any access control constraints placed on the data by the
originating server.

The largest collection of entries, starting at an entry that is
mastered by a particular server, and including all its subordinates
and their subordinates, down recognize.

Changes to the entries which are mastered by LDAP protocol other than those described in [LDAPIANA]
require a different servers, version number. A client indicates the version it
is termed a naming context. The root using as part of the DIT is bind request, described in section 4.2. If a DSA-specific Entry (DSE) and
client has not part of any naming context: each sent a bind, the server has different MUST assume the client is
using version 3 or later.

Clients may determine the protocol versions a server supports by
reading the supportedLDAPVersion attribute values in from the root DSE. (DSA is an
X.500 term for DSE
[Models]. Servers which implement version 3 or later versions MUST
provide this attribute.

4.1. Common Elements

This section describes the directory server).

3.2.1. Attributes 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 Entries protocol exchanges, all protocol operations are
encapsulated in a common envelope, the LDAPMessage, which is defined
as follows:

Sermersheim Internet-Draft - Expires July Sep 2002 Page 4
Lightweight Directory Access Protocol Version 3

Entries consist of a set

modDNRequest ModifyDNRequest,
modDNResponse ModifyDNResponse,
compareRequest CompareRequest,
compareResponse CompareResponse,
abandonRequest AbandonRequest,
extendedReq ExtendedRequest,
extendedResp ExtendedResponse },
controls [0] Controls OPTIONAL }

MessageID ::= INTEGER (0 .. maxInt)

maxInt INTEGER ::= 2147483647 -- (2^^31 - 1) --

The function of attributes. 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 LDAPMessage is to construct and compare
values of that attribute, and other functions. Options indicate modes
of transfer and other functions.

An example of provide an attribute is "mail". There may be one or more values
of envelope containing
common fields required in all protocol exchanges. At this attribute, they must be IA5 (ASCII) strings, and they time the
only common fields are
case insensitive (e.g. "foo@bar.com" will match "FOO@BAR.COM").

Schema is the collection of attribute type definitions, object class
definitions message ID and other information which a the controls.

If the server uses to determine
how to match a filter or attribute value assertion (in receives a compare
operation) against PDU from the attributes of an entry, and whether to permit
add and modify operations. The definition of schema for use with LDAP
is given in [RFC2252] and [X.501]. Additional schema elements may be
defined client in other documents.

Each entry MUST have an objectClass attribute. The objectClass
attribute specifies the object classes of an entry, which along with
the system and user schema determine the permitted attributes of an
entry. Values of this attribute may LDAPMessage
SEQUENCE tag cannot be modified by clients, but recognized, the
objectClass attribute messageID cannot be removed. Servers may restrict the
modifications of this attribute to prevent parsed,
the basic structural class tag of the entry from being changed (e.g. one cannot change a person into protocolOp is not recognized as a country). When creating an entry request, or adding an objectClass value to
an entry, all superclasses of the named classes are implicitly added
as well if not already present, and the client must supply values for
any mandatory attributes of new superclasses.

Some attributes, termed operational attributes (as defined in Section
12.4.1
encoding structures or lengths of [X.501]), are used by servers for administering the
directory system itself. They are not returned in search results
unless explicitly requested by name. Attributes which data fields are not
operational, such as "mail", will have their schema and syntax
constraints enforced by servers, but servers will generally not make
use of their values.

Servers MUST NOT permit clients to add attributes found to an entry unless
those attributes are permitted by be
incorrect, then the object class definitions, server MUST return the
schema controlling that entry (specified notice of disconnection
described in the subschema � see
below), or are operational attributes known to that server section 4.4.1, with resultCode protocolError, and used
for administrative purposes. Note that there is a particular
objectClass 'extensibleObject' defined in [RFC2252] which permits all
user attributes to be present in an entry.

Entries MAY contain, among others,
immediately close the following operational
attributes, defined in [RFC2252]. These attributes are maintained
automatically by connection. In other cases that the server and are not modifiable
cannot parse the request received by clients:

- creatorsName: the Distinguished Name of client, the user who added this
entry server MUST
return an appropriate response to the directory.

Sermersheim Internet-Draft - Expires July 2002 Page 5
Lightweight Directory Access Protocol Version 3

- createTimestamp: request, with the time this entry was added resultCode
set to protocolError.

If the directory.

- modifiersName: the Distinguished Name of client receives a PDU from the user who last
modified this entry.

- modifyTimestamp: server, which cannot be parsed,
the time this entry was last modified.

- subschemaSubentry: client may discard the Distinguished Name of PDU, or may abruptly close the subschema entry
(or subentry) which controls the schema for this entry.

3.2.2. Subschema Entries and Subentries

Subschema entries are used for administering information about the
directory schema, connection.

The ASN.1 type Controls is defined in particular section 4.1.12.

4.1.1.1. Message ID

All LDAPMessage envelopes encapsulating responses contain the object classes and attribute
types supported by directory servers. A single subschema entry
contains all schema definitions used by entries in a particular part
messageID value of the directory tree.

Servers which follow X.500(93) models SHOULD implement subschema
using the X.500 subschema mechanisms, and so these subschemas are not
ordinary entries. LDAP clients SHOULD NOT assume that servers
implement any corresponding request LDAPMessage.

The message ID of a request MUST have a non-zero value different from
the other aspects values of X.500 subschema. A server which
masters entries and permits clients to modify these entries MUST
implement and provide access to these subschema entries, so that its
clients may discover any other requests outstanding in the attributes and object classes LDAP session of
which are
permitted to be present. It is strongly recommended that all other
servers implement this as well. message is a part. The following four attributes MUST be present in all subschema
entries:

- cn: this attribute zero value is reserved for the
unsolicited notification message.

A client MUST be used to form NOT send a second request with the RDN of same message ID as
an earlier request on the subschema
entry.

- objectClass: same connection if the attribute MUST have at least client has not
received the values "top" and
"subschema".

- objectClasses: each value of this attribute specifies an object
class known to final response from the server.

- attributeTypes: earlier request. Otherwise the
behavior is undefined. Typical clients increment a counter for each value
request.

A client MUST NOT reuse the message id of this attribute specifies an
attribute type known to abandonRequest or of the server.

These are defined in [RFC2252]. Other attributes MAY be present in
subschema entries, to reflect additional supported capabilities.

These include matchingRules, matchingRuleUse, dITStructureRules,
dITContentRules, nameForms and ldapSyntaxes.

Servers SHOULD provide
abandoned operation until it has received a response from the attributes createTimestamp and
modifyTimestamp in subschema entries, in order to allow clients server
for another request invoked subsequent to
maintain their caches of schema information. the abandonRequest, as the
abandonRequest itself does not have a response.

Sermersheim Internet-Draft - Expires July Sep 2002 Page 6 5
Lightweight Directory Access Protocol Version 3

Clients MUST only retrieve attributes from a subschema entry by
requesting a base object search of the entry, where the search filter
is "(objectClass=subschema)". This will allow LDAPv3 servers which
gateway to X.500(93) to detect that subentry information

4.1.2. String Types

The LDAPString is being
requested.

3.3. Relationship a notational convenience to X.500

This document defines LDAP in terms indicate that, although
strings of X.500 LDAPString type encode as an X.500 access
mechanism. An LDAP server MUST act in accordance with OCTET STRING types, the X.500(1993)
series
[ISO10646] character set (a superset of ITU recommendations when providing the service. However, it Unicode) is not required used, encoded
following the UTF-8 algorithm [RFC2044]. Note that an LDAP server make use of any X.500 protocols in providing this service, e.g. LDAP can be mapped onto any other
directory system so long as the X.500 data and service model as used
in LDAP is not violated in UTF-8
algorithm characters which are the LDAP interface.

3.4. Server-specific Data Requirements

An LDAP server MUST provide information about itself and other
information that is specific to each server. This is same as ASCII (0x0000 through
0x007F) are represented as that same ASCII character in a
group single
byte. The other byte values are used to form a variable-length
encoding of attributes located in the root DSE (DSA-Specific Entry),
which an arbitrary character.

LDAPString ::= OCTET STRING -- UTF-8 encoded,
-- ISO 10646 characters

The LDAPOID is named with the zero-length LDAPDN. These attributes are
retrievable if a client performs notational convenience to indicate that the
permitted value of this string is a base object search (UTF-8 encoded) dotted-decimal
representation of an OBJECT IDENTIFIER. Although an LDAPOID is
encoded as an OCTET STRING, values are limited to the root
with filter "(objectClass=*)", however they definition of
numericoid given in Section 1.3 of [Models].

LDAPOID ::= OCTET STRING -- Constrained to numericoid [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 subject respectively defined to access
control restrictions. The root DSE MUST NOT be included if the client
performs
representation of a subtree search starting from distinguished-name and a relative-distinguished-
name after encoding according to the root.

Servers may allow clients specification in [LDAPDN].

LDAPDN ::= LDAPString
-- Constrained to modify these attributes. distinguishedName [LDAPDN]

RelativeLDAPDN ::= LDAPString
-- Constrained to name-component [LDAPDN]

4.1.5. Attribute Descriptions

The following attributes of the root DSE definition and encoding rules for attribute descriptions are
defined in section 5 Section 2.5 of
[RFC2252]. Additional attributes may be defined in other documents. [Models]. Briefly, an attribute description
is an attribute type and zero or more options.

AttributeDescription ::= LDAPString
-- Constrained to attributedescription
-- [Models]

Examples of valid AttributeDescription:

Sermersheim Internet-Draft - namingContexts: naming contexts Expires Sep 2002 Page 6
Lightweight Directory Access Protocol Version 3

cn
userCertificate;binary

Not all options can be associated with attributes held in the server. Naming
contexts are defined
directory. A server will treat an AttributeDescription with any
options it does not implement or support as unrecognized. The order
in section 17 of [X.501].

- subschemaSubentry: subschema entry (or subentry) holding the
schema for the root DSE.

- altServer: alternative servers which options appear in case this one is later
unavailable.

- supportedExtension: the list of supported extended operations.

- supportedControl: MUST NOT be used to impart any
semantic meaning. Servers MUST treat any two AttributeDescription
with the same AttributeType and options as equivalent.

AttributeDescriptionList describes a list of supported controls.

- supportedSASLMechanisms: 0 or more attribute
descriptions. (A list of supported SASL security features.

- supportedLDAPVersion: LDAP versions implemented by the server.

If the server does not master entries and does not know the locations
of schema information, zero elements has special significance in
the subschemaSubentry attribute is Search request.)

AttributeDescriptionList ::= SEQUENCE OF
AttributeDescription

4.1.5.1 Transfer Options

Transfer options are not present held in the root DSE. If directory, they only affect the server masters directory entries under one or
more schema rules,
encoding used to transfer values. The absence of a transfer option
implies the schema native encoding.

Transfer options are mutually exclusive. Specifying a transfer option
when requesting attributes to be returned in a SearchRequest causes
that encoding to be used for each entry is found by reading that attribute and its subtypes. That
is, requesting name;binary requests the
subschemaSubentry attribute for that entry.

Sermersheim Internet-Draft - Expires July 2002 Page 7
Lightweight Directory Access Protocol Version 3

4. Elements of Protocol

The LDAP protocol is described using Abstract Syntax Notation 1
(ASN.1) [X.680], name and is transferred its
subtypes (e.g., cn, sn, cn;lang_en, etc.) be returned using binary
transfer.

When specifying return attributes for a subset SearchRequest, clients SHOULD
avoid requesting the return of ASN.1 Basic
Encoding Rules [X.690]. In order to support future extensions attributes related to this
protocol, clients each other in
the attribute subtyping hierarchy with different transfer encodings.
For example, requesting name;lang_en;binary and servers MUST ignore elements of SEQUENCE
encodings whose tags they do not recognize. Section 5.1 specifies cn should be avoided
as it ambiguous as to how cn;lang_en is to be transferred. In such
cases, the protocol server's behavior is encoded undefined (the server can return the
values in either, neither, or both encodings).

One transfer option, "binary", is defined in this document.
Additional options may be defined in IETF standards-track and transferred.

Note
experimental RFCs. Options beginning with "x-" are reserved for
private experiments.

4.1.5.2. Binary Transfer Option

If the "binary" option is present in an AttributeDescription, it
specifies that unlike X.500, each change to data within the LDAP AttributeValue(s) of the attribute be
transferred in protocol other than
through as BER encoded data according to the extension mechanisms will have a different version
number. A client will indicate ASN.1
data type corresponding to the version it supports as attribute's LDAP syntax. The LDAP
syntax is indicated by the "SYNTAX" part of the
bind request, described
AttributeTypeDescription.

Sermersheim Internet-Draft - Expires Sep 2002 Page 7
Lightweight Directory Access Protocol Version 3

The presence or absence of the "binary" option only affects the
transfer of attribute values in section 4.2. protocol; servers store any
particular attribute in a server-defined format. If a client has not sent requests
that a
bind, the server MUST assume that version 3 or later is supported return an attribute in the client (since version 2 required that "binary" format, but the client bind first).

Clients may determine
server cannot generate that format, the protocol versions a server supports by
reading MUST treat the supportedLDAPVersion attribute from the root DSE. Servers
which implement version 3 or later versions MUST provide this
attribute. Servers which only implement version 2 may not 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:

LDAPMessage ::= SEQUENCE {
messageID MessageID,
protocolOp CHOICE {
bindRequest BindRequest,
bindResponse BindResponse,
unbindRequest UnbindRequest,
searchRequest SearchRequest,
searchResEntry SearchResultEntry,
searchResDone SearchResultDone,
searchResRef SearchResultReference,
modifyRequest ModifyRequest,
modifyResponse ModifyResponse,
addRequest AddRequest,
addResponse AddResponse,
delRequest DelRequest,
delResponse DelResponse,
modDNRequest ModifyDNRequest,
modDNResponse ModifyDNResponse,
compareRequest CompareRequest,

Sermersheim Internet-Draft - Expires July 2002 Page 8
Lightweight Directory Access Protocol Version 3

compareResponse CompareResponse,
abandonRequest AbandonRequest,
extendedReq ExtendedRequest,
extendedResp ExtendedResponse },
controls [0] Controls OPTIONAL }

MessageID ::= INTEGER (0 .. maxInt)

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 MUST return the notice of disconnection
described in section 4.4.1, with resultCode protocolError, and
immediately close the connection. In other cases that the server
cannot parse the request received by the client, the server MUST
return an appropriate response to the request, with the resultCode
set to protocolError.

If the client receives a PDU from the server, which cannot be parsed,
the client may discard the PDU, or may abruptly close the connection.

The ASN.1 type Controls is defined in section 4.1.12.

4.1.1.1. Message ID

All LDAPMessage envelopes encapsulating responses contain the
messageID value of the corresponding request LDAPMessage.

The message ID of a request MUST have a value different from the
values of any other requests outstanding in the LDAP session of which
this message is a part.

A client MUST NOT send a second request with the same message ID as
an earlier request on the same connection if the client has not
received the final response from the earlier request. Otherwise the
behavior is undefined. Typical clients increment a counter for each
request.

A client MUST NOT reuse the message id of an abandonRequest or of the
abandoned operation until it has received a response from the server
for another request invoked subsequent to the abandonRequest, as the
abandonRequest itself does not have a response.

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

Sermersheim Internet-Draft - Expires July 2002 Page 9
Lightweight Directory Access Protocol Version 3

[ISO10646] character set (a superset of Unicode) is used, encoded
following the UTF-8 algorithm [RFC2044]. 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.

LDAPString ::= OCTET STRING

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.

LDAPOID ::= OCTET STRING

A value of LDAPOID is defined by the following ABNF [RFC2234]:

ldapOID = number *( DOT number )

number = ( LDIGIT *DIGIT ) / DIGIT

DOT = %x2E ; "."

LDIGIT = %x31-39 ; 1-9

DIGIT = %x30 / LDIGIT ; 0-9

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 [RFC2253], such
that:

distinguished-name = name

relative-distinguished-name = name-component

where name and name-component are as defined in [RFC2253].

LDAPDN ::= LDAPString

RelativeLDAPDN ::= LDAPString

Only Attribute Types can be present in a relative distinguished name
component--the options of Attribute Descriptions (next section) MUST
NOT be used in specifying distinguished names.

4.1.4. Attribute Type

Sermersheim Internet-Draft - Expires July 2002 Page 10
Lightweight Directory Access Protocol Version 3

An AttributeType takes on as its value the textual string associated
with that AttributeType in its specification.

AttributeType ::= LDAPString

Each attribute type has a unique OBJECT IDENTIFIER which has been
assigned to it. This identifier may be written as defined by ldapOID
in section 4.1.2.

A specification may also assign one or more textual names for an
attribute type. These names MUST begin with a letter, and only
contain ASCII letters, digit characters and hyphens. They are case
insensitive. These ASCII characters are identical to ISO 10646
characters whose UTF-8 encoding is a single byte between 0x00 and
0x7F.

If the server has a textual name for an attribute type, it MUST use a
textual name for attributes returned in search results. The dotted-
decimal OBJECT IDENTIFIER is only used if there is no textual name
for an attribute type.

Attribute type textual names are non-unique, as two different
specifications (neither in standards track RFCs) may choose the same
name.

A server which masters or shadows entries SHOULD list all the
attribute types it supports in the subschema entries, using the
attributeTypes attribute. Servers which support an open-ended set of
attributes SHOULD include at least the attributeTypes value for the
'objectClass' attribute. Clients MAY retrieve the attributeTypes
value from subschema entries in order to obtain the OBJECT IDENTIFIER
and other information associated with attribute types.

Some attribute type names which are used in this version of LDAP are
described in [RFC2252]. Servers may implement additional attribute
types.

4.1.5. Attribute Description

An AttributeDescription is a superset of the definition of the
AttributeType. It has the same ASN.1 definition, but allows
additional options to be specified. The entire AttributeDescription
is case insensitive.

AttributeDescription ::= LDAPString

A value of AttributeDescription is based on the following ABNF:

attributeDescription = attributeType options

attributeType = AttributeType
; as described in Section 4.1.4

options = *( SEMICOLON options )

Sermersheim Internet-Draft - Expires July 2002 Page 11
Lightweight Directory Access Protocol Version 3

option = 1*opt-char

opt-char = ALPHA / DIGIT / HYPHEN

SEMICOLON = %x3B ; ";"

ALPHA = %x41-5A / %x61-7A ; A-Z / a-z

HYPHEN = %x2D ; "-"

Examples of valid AttributeDescription:

cn
userCertificate;binary

Not all options can be associated with attributes held in the
directory. A server will treat an AttributeDescription with any
options it does not implement as unrecognized. The order in which
options appear in the list MUST NOT be used to impart any semantic
meaning. Servers MUST treat any two AttributeDescription with the
same AttributeType and options as equivalent.

An attribute description that contains mutually exclusive options
shall be treated as unrecognized. That is, "cn;binary;gser" (where
"binary" and "gser" are mutually exclusive) is to be treated as an
unrecognized attribute.

There are multiple kinds of attribute description options. The LDAP
technical specification details two kinds: tagging options (such as
language tag options) and transfer options (such as ;binary). Other
documents may detail other kinds.

Tagging options can be held in the directory and are never mutually
exclusive. An attribute with N tagging options is considered a direct
subtype of all attributes of the same type and all but one of the N
options. If the type has a supertype, then the attribute is also
considered a direct subtype of the attribute of the supertype and the
N tagging options. That is, cn;lang_de;lang_en is considered a direct
subtype of cn;lang_de, cn;lang_en, and name;lang_de;lang_en (cn is a
subtype of name).

Transfer options are not held in the directory, they only affect the
encoding used to transfer values. The absence of a transfer option
implies the native encoding. Transfer options are mutually exclusive.
Specifying a transfer option when requesting attributes to be
returned in a SearchRequest causes that encoding to be used for that
attribute and its subtypes. That is, requesting name;binary requests
the attribute name and its subtypes (e.g., cn, sn, cn;lang_en, etc.)
be returned using binary transfer.

When specifying return attributes for a SearchRequest, clients SHOULD
avoid requesting the return of attributes related to each other in
the attribute subtyping hierarchy with different transfer encodings.

Sermersheim Internet-Draft - Expires July 2002 Page 12
Lightweight Directory Access Protocol Version 3

For example, requesting name;lang_en;binary and cn should be avoided
as it ambiguous as to how cn;lang_en is to be transferred. In such
cases, the server's behavior is undefined (the server can return the
values in either, neither, or both encodings).

Other documents may specify other kinds of options. These documents
must detail how new kinds of options relate to tagging and transfer
options. In particular, the document must describe how the options
relation to the attribute subtyping hierarchy.

One transfer option, "binary", is defined in this document.
Additional options may be defined in IETF standards-track and
experimental RFCs. Options beginning with "x-" are reserved for
private experiments.

The data type "AttributeDescriptionList" describes a list of 0 or
more attribute types. (A list of zero elements has special
significance in the Search request.)

AttributeDescriptionList ::= SEQUENCE OF
AttributeDescription

4.1.5.1. Binary Option

If the "binary" option is present in an AttributeDescription, it
overrides the native encoding representation defined for that
attribute in [RFC2252]. Instead the attribute is to be transferred as
a binary value encoded using the Basic Encoding Rules [X.690]. The
syntax of the binary value is an ASN.1 data type definition, which is
referenced by the "SYNTAX" part of the attribute type definition.

The presence or absence of the "binary" option only affects the
transfer of attribute values in protocol; servers store any
particular attribute in a single format. If a client requests that a
server return an attribute in the binary format, but the server
cannot generate that format, the server MUST treat this
attribute type as an unrecognized attribute type. unrecognized. Similarly, clients MUST NOT expect
servers to return an attribute in binary format with the "binary" option if the client
requested that attribute by name without the "binary" option.

This option is intended to be used with attributes whose syntax is a
complex ASN.1 data type, and the structure of values of that but may be associated with any attribute
whose ASN.1 type is
needed by clients. Examples of this kind of syntax are "Certificate"
and "CertificateList". known.

4.1.6. Attribute Value

A field of type AttributeValue is an OCTET STRING containing an
encoded value of an AttributeValue data type. The value is encoded
according to its native encoding definition, unless an option
specifying the transfer encoding is present in the companion
AttributeDescription to the AttributeValue (e.g. "binary").

Sermersheim Internet-Draft - Expires July 2002 Page 13
Lightweight Directory Access Protocol Version 3

The native encoding definitions for different syntaxes and attribute
types may be found in other documents, and in particular [RFC2252]. [Syntaxes].

At the time of this writing, there is only one AttributeDescription
option used to specify transfer encoding--"binary", described in
section 4.1.5.1. 4.1.5.2.

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.

Clients MUST NOT send attribute values in a request that are not
valid according to the syntax defined for the attributes.

4.1.7. Attribute Value Assertion

The AttributeValueAssertion type definition is similar to the one in
the X.500 directory standards. It contains an attribute description
and a matching rule assertion value suitable for that type.

AttributeValueAssertion ::= SEQUENCE {

Sermersheim Internet-Draft - Expires Sep 2002 Page 8
Lightweight Directory Access Protocol Version 3

attributeDesc AttributeDescription,
assertionValue AssertionValue }

AssertionValue ::= OCTET STRING

If an option specifying the a transfer encoding option is present in attributeDesc, the assertionValue
is encoded as specified by the option. For example, if the "binary"
option is present in the attributeDesc, the AssertionValue is BER
encoded.

For all the string-valued user attributes described in [RFC2252], [Syntaxes],
the assertion value syntax is the same as the value syntax. Clients
may use attribute values as assertion values in compare requests and
search filters.

Note however that the assertion syntax may be different from the
value syntax for other attributes or for non-equality matching rules.
These may have an assertion syntax which contains only part of the
value. See section 20.2.1.8 of [X.501] for examples.

4.1.8. Attribute

An attribute consists of a type an attribute description and one or more
values of that type. attribute description. (Though attributes MUST have at
least one value when stored, due to access control restrictions the
set may be empty when transferred

Sermersheim Internet-Draft - Expires July 2002 Page 14
Lightweight Directory Access Protocol Version 3 from the server to the client. This
is described in section 4.5.2, concerning the PartialAttributeList
type.)

Attribute ::= SEQUENCE {
type AttributeDescription,
vals SET OF AttributeValue }

Each attribute value is distinct in the set (no duplicates). The
order set
of attribute values within the vals set is undefined and
implementation-dependent, and unordered. Implementations MUST NOT be relied upon. reply upon
any apparent ordering being repeatable.

4.1.9. Matching Rule Identifier

A matching rule is a means of expressing how a server should compare
an AssertionValue received in a search filter with an abstract data
value. The matching rule defines the syntax of the assertion value
and the process to be performed in the server.

An X.501 (1993) Matching Rule is identified in the LDAP protocol by
the printable representation of its OBJECT IDENTIFIER, either as one
of the strings given in [RFC2252], [Syntaxes], or as decimal digits with
components separated by periods, e.g. "caseIgnoreIA5Match" or
"1.3.6.1.4.1.453.33.33".

MatchingRuleId ::= LDAPString

Sermersheim Internet-Draft - Expires Sep 2002 Page 9
Lightweight Directory Access Protocol Version 3

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 matching rule can be used. More
information is given in section 4.5 of [RFC2252]. [Syntaxes].

4.1.10. 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 LDAPResponse to indicate the final
status of a protocol operation request.

Sermersheim Internet-Draft - Expires July 2002 Page 15
Lightweight Directory Access Protocol Version 3
adminLimitExceeded (11),
unavailableCriticalExtension (12),
confidentialityRequired (13),
saslBindInProgress (14),
noSuchAttribute (16),
undefinedAttributeType (17),
inappropriateMatching (18),
constraintViolation (19),
attributeOrValueExists (20),
invalidAttributeSyntax (21),
-- 22-31 unused --
noSuchObject (32),
aliasProblem (33),
invalidDNSyntax (34),
-- 35 reserved for undefined isLeaf --
aliasDereferencingProblem (36),
-- 37-47 unused --
inappropriateAuthentication (48),
invalidCredentials (49),
insufficientAccessRights (50),
busy (51),
unavailable (52),
unwillingToPerform (53),
loopDetect (54),
-- 55-63 unused --

Sermersheim Internet-Draft - Expires Sep 2002 Page 10
Lightweight Directory Access Protocol Version 3

namingViolation (64),
objectClassViolation (65),
notAllowedOnNonLeaf (66),
notAllowedOnRDN (67),
entryAlreadyExists (68),
objectClassModsProhibited (69),
-- 70 reserved for CLDAP --
affectsMultipleDSAs (71),
-- 72-79 unused --
other (80) (80),
... },
-- 81-90 reserved for APIs --
matchedDN LDAPDN,
errorMessage LDAPString,
referral [3] Referral OPTIONAL }

All the

The result codes with the exception of success, compareFalse and
compareTrue are to be treated enumeration is extensible as meaning the operation could not be
completed defined in its entirety.

Most Section 3.5
of [LDAPIANA]. The meanings of the result codes are based on problem indications from X.511
error data types. Result codes from 16 to 21 indicate an
AttributeProblem, codes 32, 33, 34 and 36 indicate a NameProblem,
codes 48, 49 and 50 indicate a SecurityProblem, codes 51 to 54
indicate a ServiceProblem, and codes 64 to 69 and 71 indicates an
UpdateProblem.

If a client receives a result code which is not listed above, it is
to be treated as an unknown error condition.

Sermersheim Internet-Draft - Expires July 2002 Page 16
Lightweight Directory Access Protocol Version 3 given in Appendix
A.

The errorMessage 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)
error diagnostic. As this error diagnostic is not standardized,
implementations MUST NOT rely on the values returned. If the server
chooses not to return a textual diagnostic, the errorMessage field of
the LDAPResult type MUST contain a zero length string.

For result codes of 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.
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]. The matchedDN field is to be set to contains a zero length string with
all other result codes.

4.1.11. 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 LDAPResult.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.

The referral is not returned for a singleLevel or wholeSubtree search
in which the search scope spans multiple naming contexts, and several
different servers would need to be contacted to complete the

Sermersheim Internet-Draft - Expires Sep 2002 Page 11
Lightweight Directory Access Protocol Version 3

operation. Instead, continuation references, described in section
4.5.3, are returned.

Referral ::= SEQUENCE OF LDAPURL -- one or more

LDAPURL ::= LDAPString -- limited to characters permitted in
-- URLs

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
operation.

URLs for servers implementing the LDAP protocol are written according
to [RFC2255]. [LDAPDN]. If an alias was dereferenced, the <dn> part of the URL
MUST be present, with the new target object name. If the <dn> 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. Some servers (e.g.
participating in distributed indexing) may provide a different filter
in a referral for a search operation. If the filter part of the URL
is present in an LDAPURL, the client MUST use this filter in its next

Sermersheim Internet-Draft - Expires July 2002 Page 17
Lightweight Directory Access Protocol Version 3
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.

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].

Other kinds of URLs may be returned, so long as the operation could
be performed using that protocol.

4.1.12. Controls

A control is a way to specify extension information. Controls which
are sent as part of a request apply only to that request and are not
saved.

Controls ::= SEQUENCE OF Control

Control ::= SEQUENCE {
controlType LDAPOID,
criticality BOOLEAN DEFAULT FALSE,
controlValue OCTET STRING OPTIONAL }

The controlType field MUST be a UTF-8 encoded dotted-decimal
representation of an OBJECT IDENTIFIER which uniquely identifies the
control. This prevents conflicts between control names.

The criticality field is either TRUE or FALSE and is only used when a
control accompanies one of the following requests: bindRequest,

Sermersheim Internet-Draft - Expires Sep 2002 Page 12
Lightweight Directory Access Protocol Version 3

searchRequest, modifyRequest, addRequest, delRequest, modDNRequest,
compareRequest, or extendedReq. The use of the criticality field for
a control that is part of any other operation is ignored and treated
as 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 return the
resultCode 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, and its format is defined for the control. Implementations
MUST be prepared to handle arbitrary contents of the controlValue
octet string, including zero bytes. It is absent only if there is no
value information which is associated with a control of its type.

Sermersheim Internet-Draft - Expires July 2002 Page 18
Lightweight Directory Access Protocol Version 3

This document does not define any controls. Controls may be defined
in other documents. The definition of a control consists of:

- the OBJECT IDENTIFIER assigned to the control,

- whether the control is always noncritical, always critical, or
critical at the client's option,

- the format of the controlValue contents of the control.

Servers list the controlType of all recognized controls which they recognize in the
supportedControl attribute in the root DSE.

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 BindRequest, the implied identity is anonymous. Refer to
[AuthMeth] for the authentication-related semantics of this
operation.

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,

Sermersheim Internet-Draft - Expires Sep 2002 Page 13
Lightweight Directory Access Protocol Version 3

-- 1 and 2 reserved
sasl [3] SaslCredentials SaslCredentials,
... }

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 session. 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 client requests protocol version 2, a server that supports the version 2 protocol as described in
[RFC1777] will not return any v3-specific protocol fields. (Note
that does not all LDAP servers will support protocol version 2, since
they may be unable to generate the attribute syntaxes associated
with version 2.) specified
version, it responds with protocolError in the resultCode field of
the BindResponse.

- 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, when authentication
has been performed at a lower layer, or when using SASL
credentials with a mechanism that includes the name in the
credentials. Server behavior is undefined when the name is a null
value, simple authentication is used, and a password is specified.

Sermersheim Internet-Draft - Expires July 2002 Page 19
Lightweight Directory Access Protocol Version 3
Note that the server SHOULD NOT perform any 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
result code of the BindResponse.

Upon receipt of a Bind Request, a protocol server will authenticate
the requesting client, if necessary. The server will then return a
Bind Response to the client indicating the status of the
authentication.

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.

4.2.1. Sequencing of the Bind Request

For some SASL authentication mechanisms, it may be necessary for the
client to invoke the BindRequest multiple times. 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 Bind requests made as part of a multi-stage bind.

A client may abort a SASL bind negotiation by sending a BindRequest
with a different value in the mechanism field of SaslCredentials, or
an AuthenticationChoice other than sasl.

If the client sends a BindRequest with the sasl mechanism field as an
empty string, the server MUST return a BindResponse with
authMethodNotSupported as the resultCode. This will allow clients to
abort a negotiation if it wishes to try again with the same SASL
mechanism.

Unlike LDAP v2, the client need not send a Bind Request in the first
PDU of the connection. The client may request any operations and the
server MUST treat these as anonymous. If the server requires that the
client bind before browsing or modifying the directory, the server
MAY reject a request other than binding, unbinding or an extended
request with the "operationsError" result.

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
or authentication mechanisms, it may be necessary for the
client chooses not to bind on the existing connection, it will
close invoke 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 BindRequest multiple bind requests on a connection times. If at any stage the
client wishes to change
their credentials. A subsequent abort the bind process has the effect of
abandoning all operations outstanding on the connection. (This
simplifies server implementation.) Authentication from earlier binds
are subsequently ignored, it MAY unbind and so if the bind fails, then drop
the connection
will be treated underlying connection. Clients MUST NOT invoke operations between
two Bind requests made as anonymous. If part of a SASL transfer encryption or multi-stage bind.

Sermersheim Internet-Draft - Expires July Sep 2002 Page 20 14
Lightweight Directory Access Protocol Version 3

integrity mechanism has been negotiated, and that mechanism does not
support the changing of credentials from one identity to another,
then the

A client MUST instead establish may abort a new connection.

4.2.2. Authentication and Other Security Services

The simple authentication option provides minimal authentication
facilities, SASL bind negotiation by sending a BindRequest
with the contents of the authentication field consisting
only of a cleartext password. Note that different value in the use mechanism field of cleartext
passwords is not recommended over open networks when the underlying
transport service cannot guarantee confidentiality; see the "Security
Considerations" section. SaslCredentials, or
an AuthenticationChoice other than sasl.

If anonymous authentication is to be performed, then the simple
authentication option MUST be chosen, and the password be of zero
length. (This is often done by LDAPv2 clients.) Typically client sends a BindRequest with the name is
also of zero length.

The sasl choice allows for any mechanism defined for use field as an
empty string, the server MUST return a BindResponse with SASL
[RFC2222]. The mechanism field contains
authMethodNotSupported as the name of resultCode. This will allow clients to
abort a negotiation if it wishes to try again with the same SASL
mechanism.
The credentials field contains

If the arbitrary data used for
authentication, inside an OCTET STRING wrapper. Note that unlike some
Internet application protocols where SASL is used, LDAP is client did not text-
based, thus no base64 transformations are performed on the
credentials. bind before sending a request and receives an
operationsError, it may then send a Bind Request. If any SASL-based integrity this also fails
or confidentiality services are enabled,
they take effect following the transmission by client chooses not to bind on the server existing connection, it will
close the connection, reopen it and
reception begin again by the client of the final BindResponse first sending a
PDU with resultCode
success.

The client can request that the server use authentication information
from a lower layer protocol by using the SASL EXTERNAL mechanism. Bind Request. This will aid in interoperating with servers
implementing other versions of LDAP.

4.2.3. Bind Response

The Bind Response is defined as follows.

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.

If the bind was successful, the resultCode will be success, otherwise
it will be one of:

- operationsError: server encountered an internal error.

- protocolError: unrecognized version number or incorrect PDU
structure.

- authMethodNotSupported: unrecognized SASL mechanism name.

Sermersheim Internet-Draft - Expires July 2002 Page 21
Lightweight Directory Access Protocol Version 3

- strongAuthRequired: the server requires authentication be
performed with a SASL mechanism.

- referral: this server cannot accept this bind and the client
should try another.

- saslBindInProgress: the server requires the client to send a new
bind request, with the same sasl mechanism, to continue the
authentication process.

- inappropriateAuthentication: the server requires the client which
had attempted to bind anonymously or without supplying credentials
to provide some form of credentials.

Sermersheim Internet-Draft - Expires Sep 2002 Page 15
Lightweight Directory Access Protocol Version 3

- invalidCredentials: the wrong password was supplied or the SASL
credentials could not be processed.

- unavailable: the server is shutting down.

If the server does not support the client's requested protocol
version, it MUST set the resultCode to protocolError.

If the client receives a BindResponse response where the resultCode
was 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 password 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 result.

4.3. Unbind Operation

The function of the Unbind Operation is to terminate a protocol
session. 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 may assume that the protocol session
is terminated. Upon receipt of an UnbindRequest, a protocol server
may assume that the requesting client has terminated the session and
that all outstanding requests may be discarded, and may close the
connection.

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

Sermersheim Internet-Draft - Expires July 2002 Page 22
Lightweight Directory Access Protocol Version 3
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.

One unsolicited notification (Notice of Disconnection) is defined in
this document.

Sermersheim Internet-Draft - Expires Sep 2002 Page 16
Lightweight Directory Access Protocol Version 3

4.4.1. Notice of Disconnection

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 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 resultCode values are to be used in this notification:

- protocolError: The server has received data from the client in
which the LDAPMessage structure could not be parsed.

- strongAuthRequired: The server has detected that an established
underlying security association protecting communication between
the client and server has unexpectedly failed or been compromised.

- 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.

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.

Sermersheim Internet-Draft - Expires July 2002 Page 23
Lightweight Directory Access Protocol Version 3

4.5.1. Search Request

The Search Request is defined as follows:

SearchRequest ::= [APPLICATION 3] SEQUENCE {
baseObject LDAPDN,
scope ENUMERATED {
baseObject (0),
singleLevel (1),

Sermersheim Internet-Draft - Expires Sep 2002 Page 17
Lightweight Directory Access Protocol Version 3

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 AttributeDescriptionList }

Filter ::= CHOICE {
and [0] SET SIZE (1..MAX) OF Filter,
or [1] SET SIZE (1..MAX) OF 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 {
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.

Sermersheim Internet-Draft - Expires July 2002 Page 24
Lightweight Directory Access Protocol Version 3

- 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.

- 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:

neverDerefAliases: do not dereference aliases in searching
or in locating the base object of the search;

Sermersheim Internet-Draft - Expires Sep 2002 Page 18
Lightweight Directory Access Protocol Version 3

derefInSearching: dereference aliases in subordinates of
the base object in searching, but not in locating the base
object of the search;

derefFindingBaseObj: dereference aliases in locating the
base object of the search, but not when searching
subordinates of the base object;

derefAlways: dereference aliases both in searching and in
locating the base object of the search.

- 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.

- typesOnly: An indicator as to whether search results will contain
both attribute types and values, or just attribute types. Setting
this field to TRUE causes only attribute types (no values) to be
returned. Setting this field to FALSE causes both attribute types
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
'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

Sermersheim Internet-Draft - Expires July 2002 Page 25
Lightweight Directory Access Protocol Version 3
are returned as part of the search result (subject to any
applicable access control restrictions). If the filter evaluates
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 "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

Sermersheim Internet-Draft - Expires Sep 2002 Page 19
Lightweight Directory Access Protocol Version 3

is TRUE, and Undefined if it is Undefined.

The present match evaluates to TRUE where there is an attribute or
subtype of the specified attribute description present in an
entry, and FALSE otherwise (including a presence test with an
unrecognized attribute description.)

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 FALSE if applied against all
of the filters attributes in the SET OF evaluate
an entry's distinguished name as well, and also evaluates to FALSE, 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 TRUE, present so that there does not need to be
multiple versions of generic matching rules such as for word
matching, one to apply to entries and Undefined otherwise. another to apply to entries
and dn attributes as well).

A filter of item evaluates to Undefined when the "not"
choice is TRUE if 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 being negated
is FALSE, FALSE if it not recognized by the server, a matching rule id in the
extensibleMatch is TRUE, and Undefined if it not recognized by the server, the assertion
value cannot be parsed, or the type of filtering requested is Undefined.

The present match evaluates to TRUE where there not
implemented, then the filter is an Undefined. Thus for example if a
server did not recognize the attribute or
subtype type shoeSize, a filter of
(shoeSize=*) would evaluate to FALSE, and the specified attribute description present in an
entry, filters
(shoeSize=12), (shoeSize>=12) and FALSE otherwise (including a presence test with an
unrecognized (shoeSize<=12) would evaluate to
Undefined.

Servers MUST NOT return errors if attribute description.)

The extensibleMatch is new descriptions or
matching rule ids are not recognized, or assertion values cannot
be parsed. More details of filter processing are given in this version section
7.8 of [X.511].

- attributes: A list of LDAP. If the
matchingRule field is absent, attributes to be returned from each
entry which matches the type field MUST search filter. There are two special
values which may be present, used: an empty list with no attributes, and
the equality match is performed for attribute description string "*". Both of these signify that type. If the type field
is absent and matchingRule is present,
all user attributes are to be returned. (The "*" allows the matchValue is compared
against client
to request all user attributes in an entry which support that
matchingRule, and the matchingRule determines the syntax for the
assertion value (the filter item evaluates addition to TRUE if it matches
with any specified
operational attributes).

Sermersheim Internet-Draft - Expires Sep 2002 Page 20
Lightweight Directory Access Protocol Version 3

Attributes MUST be named at least one most once in the list, and are
returned at most once in an entry. If there are attribute
descriptions in the entry, FALSE if 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
match correspond to any
attribute in the entry, and Undefined use.

Client implementors should note that even if all user attributes
are requested, some attributes of the
matchingRule is entry may not recognized or the assertionValue cannot be
parsed.) If the type field is present and matchingRule is present,
the matchingRule MUST 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, since there may be one permitted extremely large number of values for
certain operational attributes. (A list of operational attributes
for use with in LDAP is given in [Syntaxes].)

Note that type,
otherwise an X.500 "list"-like operation can be emulated by the
client requesting a one-level LDAP search operation with a filter item is undefined. If the dnAttributes field
is set to TRUE,
checking for the match is applied against all presence of the attributes in
an entry's distinguished name as well, objectClass attribute, and also evaluates to TRUE
if there is at least one attribute in that an
X.500 "read"-like operation can be emulated by a base object LDAP
search operation with the distinguished name for same filter. A server which the filter item evaluates provides a
gateway to TRUE. (Editors note: The
dnAttributes field X.500 is present so that there does not need to be
multiple versions of generic matching rules such as for word
matching, one to apply to entries and another to apply to entries
and dn attributes as well).

A filter item evaluates required to Undefined when use the server would not be
able Read or List operations,
although it may choose to determine whether do so, and if it does, it must provide the assertion value matches an entry. If
an attribute description in an equalityMatch, substrings,
greaterOrEqual, lessOrEqual, approxMatch or extensibleMatch filter
is not recognized by
same semantics as the server, a matching rule id in X.500 search operation.

4.5.2. Search Result

The results of the
extensibleMatch is not recognized search attempted by the server, the assertion
value cannot be parsed, or the type server upon receipt of filtering requested is not
implemented, then the filter is Undefined. Thus for example if a
server did not recognize the attribute
Search Request are returned in Search Responses, which are LDAP
messages containing either SearchResultEntry, SearchResultReference,
or SearchResultDone data types.

SearchResultEntry ::= [APPLICATION 4] SEQUENCE {
objectName LDAPDN,
attributes PartialAttributeList }

PartialAttributeList ::= SEQUENCE OF SEQUENCE {
type shoeSize, a filter AttributeDescription,
vals SET OF AttributeValue }
-- implementors should note that the PartialAttributeList may
-- have zero elements (if none 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 attributes of that entry
-- were requested, or
matching rule ids are not recognized, could be returned), and that the vals set
-- may also have zero elements (if types only was requested, or assertion
-- all values cannot were excluded from the result.)

SearchResultReference ::= [APPLICATION 19] SEQUENCE OF LDAPURL
-- at least one LDAPURL element must be present

SearchResultDone ::= [APPLICATION 5] LDAPResult

Sermersheim Internet-Draft - Expires July Sep 2002 Page 26 21
Lightweight Directory Access Protocol Version 3

Upon receipt of a Search Request, a server will perform the necessary
search of the DIT.

If the LDAP session is operating over a connection-oriented transport
such as TCP, 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 parsed. More details returned by the server, the server will return a response
containing the SearchResultDone, which contains an indication of filter processing are given
success, or detailing any errors that have occurred.

Each entry returned in section
7.8 of [X.511].

- attributes: A list a SearchResultEntry will contain all
attributes, complete with associated values if necessary, 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 returned from each
entry which matches in binary format (indicated
by the search filter. There are two special
values which AttributeDescription in the response having the "binary"
option present).

Some attributes may be used: an empty list with no attributes, and constructed by the server and appear in a
SearchResultEntry attribute description string "*". Both list, although they are not stored
attributes of these signify an entry. Clients MUST NOT assume that all user attributes are to
can be returned. (The "*" allows modified, even if permitted by access control.

4.5.3. Continuation References in the client Search Result

If the server was able to request all user attributes in addition locate the entry referred to specific operational
attributes).

Attributes MUST be named at most once by the
baseObject but was unable to search all the entries in the list, and are
returned scope at most once in an entry. If there are attribute
descriptions in
and under the list which are not recognized, they are
ignored by baseObject, the server.

If server may return one or more
SearchResultReference entries, each containing a reference to another
set of servers for continuing the client does not want operation. A server MUST NOT return
any attributes returned, SearchResultReference if it can
specify a list containing only has not located the attribute with OID "1.1". This
OID was chosen arbitrarily baseObject and does
thus has not correspond to searched any
attribute entries; in use.

Client implementors should note that even if all user attributes
are requested, some attributes of this case it would return a
SearchResultDone containing a referral resultCode.

In the entry may not be included in
search results due absence of indexing information provided to access controls or other restrictions.
Furthermore, a server from
servers will not return operational attributes, such
as objectClasses or attributeTypes, unless they holding subordinate naming contexts, SearchResultReference
responses are listed not affected by
name, since there may be extremely large number of values for
certain operational attributes. (A list of operational attributes
for use search filters and are always returned
when in LDAP scope.

The SearchResultReference is given in [RFC2252].)

Note that an X.500 "list"-like operation can be emulated by of the
client requesting a one-level LDAP search operation with a filter
checking for same data type as the presence of Referral.
URLs for servers implementing the objectClass attribute, and that an
X.500 "read"-like operation can be emulated by a base object LDAP
search operation protocol are written according
to [LDAPDN]. The <dn> part MUST be present in the URL, with the same filter. A server which provides a
gateway to X.500 is not required to new
target object name. The client MUST use the Read or List operations,
although it this name in its next
request. Some servers (e.g. part of a distributed index exchange
system) may choose to do so, and if it does, it must provide a different filter in the
same semantics as the X.500 search operation.

4.5.2. Search Result

The results URLs of the search attempted by
SearchResultReference. If the server upon receipt filter part of a
Search Request are returned in Search Responses, which are LDAP
messages containing either SearchResultEntry, SearchResultReference,
or SearchResultDone data types.

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 URL is present in an

Sermersheim Internet-Draft - Expires July Sep 2002 Page 27 22
Lightweight Directory Access Protocol Version 3

-- have zero elements (if none of

LDAP URL, the attributes of that entry
-- were requested, or could be returned), client MUST use the new filter in its next request to
progress the search, and that if the vals set
-- may also have zero elements (if types only filter part is absent the client will
use again the same filter. If the originating search scope was requested, or
-- all values were excluded from
singleLevel, the result.)

SearchResultReference ::= [APPLICATION 19] SEQUENCE OF LDAPURL
-- at least one LDAPURL element must be present

SearchResultDone ::= [APPLICATION 5] LDAPResult

Upon receipt scope part of a Search Request, a server the URL will perform be baseObject. Other
aspects of the necessary new search of request may be the DIT.

If same or different as the LDAP session is operating over
search which generated the continuation references.
Other kinds of URLs may be returned so long as the operation could be
performed using that protocol.

The name of an unexplored subtree in a connection-oriented transport
such as TCP, SearchResultReference need not
be subordinate to the server will return base object.

In order to complete the search, the client MUST issue a sequence of
responses in separate LDAP messages. There may be zero or more
responses containing SearchResultEntry, one new search
operation for each entry found
during SearchResultReference that is returned. Note that
the search. There may also be zero or more responses
containing SearchResultReference, one for abandon operation described in section 4.11 applies only to a
particular operation sent on a connection between a client and
server, and if the client has multiple outstanding search operations,
it MUST abandon each area not explored by
this operation individually.

4.5.3.1. Example

For example, suppose the contacted server during (hosta) holds the search. The SearchResultEntry entry
"O=MNN,C=WW" and
SearchResultReference PDUs may come in any order. Following all the
SearchResultReference responses and all SearchResultEntry responses
to be returned by entry "CN=Manager,O=MNN,C=WW". It knows that
either LDAP-capable servers (hostb) or (hostc) hold
"OU=People,O=MNN,C=WW" (one is the server, master and the other server will return a response
containing the SearchResultDone, which contains an indication of
success, or detailing any errors
shadow), and that have occurred.

Each entry returned in a SearchResultEntry will contain all
attributes, complete with associated values if necessary, as
specified in the attributes field of LDAP-capable server (hostd) holds the Search Request. Return subtree
"OU=Roles,O=MNN,C=WW". If a subtree search of
attributes "O=MNN,C=WW" is subject
requested to access control and other administrative
policy. Some attributes the contacted server, it may return the following:

SearchResultEntry for O=MNN,C=WW
SearchResultEntry for CN=Manager,O=MNN,C=WW
SearchResultReference {
ldap://hostb/OU=People,O=MNN,C=WW
ldap://hostc/OU=People,O=MNN,C=WW
}
SearchResultReference {
ldap://hostd/OU=Roles,O=MNN,C=WW
}
SearchResultDone (success)

Client implementors should note that when following a
SearchResultReference, additional SearchResultReference may be returned in binary format (indicated
by the AttributeDescription in
generated. Continuing the response having example, if the "binary"
option present).

Some attributes may be constructed by client contacted the server
(hostb) and appear in a
SearchResultEntry attribute list, although they are not stored
attributes of an entry. Clients MUST NOT assume that all attributes
can be modified, even if permitted by access control.

4.5.3. Continuation References in issued the Search Result search for the subtree "OU=People,O=MNN,C=WW",
the server might respond as follows:

SearchResultEntry for OU=People,O=MNN,C=WW
SearchResultReference {
ldap://hoste/OU=Managers,OU=People,O=MNN,C=WW
}
SearchResultReference {
ldap://hostf/OU=Consultants,OU=People,O=MNN,C=WW
}

Sermersheim Internet-Draft - Expires Sep 2002 Page 23
Lightweight Directory Access Protocol Version 3

SearchResultDone (success)

If the contacted server was able to locate does not hold the entry referred to by base object for the
baseObject but was unable search,
then it will return a referral to search all the entries in the scope at
and under client. For example, if the baseObject,
client requests a subtree search of "O=XYZ,C=US" to hosta, the server
may return one or more
SearchResultReference entries, each only a SearchResultDone containing a reference referral.

SearchResultDone (referral) {
ldap://hostg/
}

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,
modification SEQUENCE OF SEQUENCE {
operation ENUMERATED {
add (0),
delete (1),
replace (2) },
modification AttributeTypeAndValues } }

AttributeTypeAndValues ::= SEQUENCE {
type AttributeDescription,
vals SET OF AttributeValue }

Parameters of the Modify Request are:

- object: The object to another
set be modified. The value 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 resultCode.

In field
contains the absence DN of indexing information provided the entry to a be modified. The server from
servers holding subordinate naming contexts, SearchResultReference
responses are will not affected by search filters and are always returned
when
perform any alias dereferencing in scope.

Sermersheim Internet-Draft determining the object to be
modified.

- Expires July 2002 Page 28
Lightweight Directory Access Protocol Version 3

The SearchResultReference is modification: A list of the same data type as the Referral.
URLs for servers implementing the LDAP protocol are written according modifications to [RFC2255]. be performed on the
entry. The <dn> part entire list of entry modifications MUST be present performed in
the URL, with order they are listed, as a single atomic operation. While
individual modifications may violate the new
target object name. The client directory schema, the
resulting entry after the entire list of modifications is
performed MUST use this name in its next
request. Some servers (e.g. part conform to the requirements of a distributed index exchange
system) the directory
schema. The values that may provide a different filter be taken on by the 'operation' field
in each modification construct have the URLs following semantics
respectively:

add: add values listed to the given attribute, creating the
attribute if necessary;

delete: delete values listed from the given attribute,
removing the entire attribute if no values are listed, or

Sermersheim Internet-Draft - Expires Sep 2002 Page 24
Lightweight Directory Access Protocol Version 3

if all current values of the
SearchResultReference. If the filter part attribute are listed for
deletion;

replace: replace all existing values of the URL is present in an
LDAP URL, the client MUST use given attribute
with the new filter in its next request to
progress values listed, creating the search, and attribute if it
did not already exist. A replace with no value will delete
the filter part entire attribute if it exists, and is absent the client will
use again ignored if the same filter. Other aspects
attribute does not exist.

The result of the new search request
may be the same or different as the search which generated modify attempted by the
continuation references.
Other kinds server upon receipt of URLs may be a
Modify Request is returned so long in a Modify Response, defined as the operation could be
performed using that protocol.

The name follows:

ModifyResponse ::= [APPLICATION 7] LDAPResult

Upon receipt of an unexplored subtree in a SearchResultReference need not
be subordinate to Modify Request, a server will perform the base object.

In order necessary
modifications to complete the search, DIT.

The server will return to the client MUST issue a new search
operation for each SearchResultReference single Modify Response
indicating either the successful completion of the DIT modification,
or the reason that is returned. the modification failed. Note that
the abandon operation described in section 4.11 applies only due to a
particular operation sent on a connection between a client and
server, and if the client has multiple outstanding search operations,
it MUST abandon each operation individually.

4.5.3.1. Example

For example, suppose
requirement for atomicity in applying the contacted server (hosta) holds list of modifications in
the entry
"O=MNN,C=WW" and Modify Request, the entry "CN=Manager,O=MNN,C=WW". It knows client may expect that
either LDAP-capable servers (hostb) or (hostc) hold
"OU=People,O=MNN,C=WW" (one is no modifications of
the master and DIT have been performed if the other server a
shadow), Modify Response received indicates
any sort of error, and that LDAP-capable server (hostd) holds all requested modifications have been
performed if the subtree
"OU=Roles,O=MNN,C=WW". If a subtree search Modify Response indicates successful completion of "O=MNN,C=WW" is
requested to
the contacted server, it may return Modify Operation. If the following:

Client implementors should note that when following a
SearchResultReference, additional SearchResultReference may be
generated. Continuing connection fails, whether the example, if
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 client contacted entry's
relative distinguished name. An attempt to do so will result in the
server
(hostb) and issued returning the search error notAllowedOnRDN. The Modify DN Operation
described in section 4.9 is used to rename an entry.

If an equality match filter has not been defined for an attribute
type, clients MUST NOT attempt to add or delete individual values of
that attribute from an entry using the subtree "OU=People,O=MNN,C=WW", "add" or "delete" form of a
modification, and MUST instead use the server might respond as follows:

SearchResultEntry for OU=People,O=MNN,C=WW

Sermersheim Internet-Draft - Expires July 2002 Page 29
Lightweight Directory Access Protocol Version 3

SearchResultReference {
ldap://hoste/OU=Managers,OU=People,O=MNN,C=WW
}
SearchResultReference {
ldap://hostf/OU=Consultants,OU=People,O=MNN,C=WW
}
SearchResultDone (success)

If "replace" form.

Note that due to the contacted server does simplifications made in LDAP, there is not hold a
direct mapping of the base object for modifications in an LDAP ModifyRequest onto the search,
then it will return
EntryModifications of a referral to DAP ModifyEntry operation, and different
implementations of LDAP-DAP gateways may use different means of
representing the client. For example, if change. If successful, the
client requests a subtree search final effect of "O=XYZ,C=US" to hosta, the server
may return only a SearchResultDone containing a referral.

SearchResultDone (referral) {
ldap://hostg/
}

4.6. Modify
operations on the entry MUST be identical.

4.7. Add Operation

The Modify Add Operation allows a client to request that a modification the addition of an entry be performed on its behalf by a server.
into the directory. The Modify Add Request is defined as follows:

ModifyRequest

AddRequest ::= [APPLICATION 6] 8] SEQUENCE {
object
entry LDAPDN,
modification SEQUENCE OF SEQUENCE {
operation ENUMERATED {
add (0),
delete (1),
replace (2) },
modification AttributeTypeAndValues }

Sermersheim Internet-Draft - Expires Sep 2002 Page 25
Lightweight Directory Access Protocol Version 3

attributes AttributeList }

AttributeTypeAndValues

AttributeList ::= SEQUENCE OF SEQUENCE {
type AttributeDescription,
vals SET OF AttributeValue }

Parameters of the Modify Add Request are:

- object: The object to be modified. The value of this field
contains entry: the DN Distinguished Name of the entry to be modified. The added. Note that
the server will not
perform dereference any alias dereferencing aliases in determining locating the object entry
to be
modified. added.

- modification: A list of modifications to be performed on the
entry. The entire list of entry modifications MUST be performed in
the order they are listed, as a single atomic operation. While
individual modifications may violate the directory schema, the
resulting entry after attributes: the entire list of modifications is
performed MUST conform to the requirements of the directory
schema. The values attributes that may be taken on by make up the 'operation' field
in each modification construct have content of the following semantics
respectively:

Sermersheim Internet-Draft - Expires July 2002 Page 30
Lightweight Directory Access Protocol Version 3

add: add
entry being added. Clients MUST include distinguished values listed to
(those forming the given attribute, creating entry's own RDN) in this list, the
attribute if necessary;

delete: delete objectClass
attribute, and values listed from of any mandatory attributes of the given attribute,
removing listed
object classes. Clients MUST NOT supply NO-USER-MODIFICATION
attributes such as the entire attribute if no values are listed, createTimestamp or
if all current values creatorsName attributes,
since the server maintains these automatically.

The entry named in the entry field of the attribute are listed AddRequest MUST NOT exist
for
deletion;

replace: replace all existing values the AddRequest to succeed. The parent of the given attribute
with entry to be added
MUST exist. For example, if the new values listed, creating client attempted to add
"CN=JS,O=Foo,C=US", the attribute if it "O=Foo,C=US" entry did not already exist. A replace exist, and the
"C=US" entry did exist, then the server would return the error
noSuchObject with no value will delete the entire attribute if it exists, and is ignored if matchedDN field containing "C=US". If the
attribute does
parent entry exists but is not exist.

The result of the modify attempted in a naming context held by the
server, the server upon receipt of SHOULD return a
Modify Request is returned referral to the server holding the
parent entry.

Servers implementations SHOULD NOT restrict where entries can be
located in a Modify Response, defined as follows:

ModifyResponse ::= [APPLICATION 7] LDAPResult the directory. Some servers MAY allow the administrator to
restrict the classes of entries which can be added to the directory.

Upon receipt of a Modify an Add Request, a server will perform the necessary
modifications attempt to perform the DIT.
add requested. The server will return to the client a single Modify Response
indicating either the successful completion result of the DIT modification,
or the reason that the modification failed. Note that due add attempt will be returned to the
requirement for atomicity in applying the list of modifications
client in the Modify Request, the client may expect that no modifications Add Response, defined as follows:

AddResponse ::= [APPLICATION 9] LDAPResult

A response of
the DIT have been performed if the Modify Response received success 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 connection fails, whether the
modification occurred or not is indeterminate.

The Modify Operation cannot be used to remove from an new entry any of
its distinguished values, those values which form the entry's
relative distinguished name. An attempt to do so will result is present in the
server returning the error notAllowedOnRDN.
directory.

4.8. Delete Operation

The Modify DN Delete Operation
described in section 4.9 is used to rename an entry.

If an equality match filter has not been defined for an attribute
type, clients MUST NOT attempt allows a client to add or delete individual values request the removal of
that attribute from an
entry using the "add" or "delete" form of a
modification, and MUST instead use the "replace" form.

Note that due to from the simplifications made in LDAP, there directory. The Delete Request is not a
direct mapping defined as follows:

DelRequest ::= [APPLICATION 10] LDAPDN

The Delete Request consists of the modifications in an LDAP ModifyRequest onto the
EntryModifications of a DAP ModifyEntry operation, and different
implementations of LDAP-DAP gateways may use different means Distinguished Name of
representing the change. If successful, entry to
be deleted. Note that the final effect of server will not dereference aliases while
resolving the
operations on name of the target entry MUST to be identical.

4.7. Add Operation removed, and that only

Sermersheim Internet-Draft - Expires July Sep 2002 Page 31 26
Lightweight Directory Access Protocol Version 3

leaf entries (those with no subordinate entries) can be deleted with
this operation.

The Add result of the delete attempted by the server upon receipt of a
Delete Request is returned 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 request change the addition leftmost (least
significant) component of the name of an entry
into in the directory, or
to move a subtree of entries to a new location in the directory. The Add
Modify DN Request is defined as follows:

AddRequest

ModifyDNRequest ::= [APPLICATION 8] 12] SEQUENCE {
entry LDAPDN,
attributes AttributeList }

AttributeList ::= SEQUENCE OF SEQUENCE {
type AttributeDescription,
vals SET OF AttributeValue
newrdn RelativeLDAPDN,
deleteoldrdn BOOLEAN,
newSuperior [0] LDAPDN OPTIONAL }

Parameters of the Add Modify DN Request are:

- entry: the Distinguished Name of the entry to be added. 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 added. changed.

- attributes: newrdn: the list RDN that will form the leftmost component of the new
name of the entry.

- deleteoldrdn: a boolean parameter that controls whether the old
RDN attribute values are to be retained as attributes that make up the content of the
entry being added. Clients MUST include distinguished values
(those forming
entry, or deleted from the entry's own RDN) in entry.

- newSuperior: if present, this list, is the objectClass
attribute, and values Distinguished Name of any mandatory attributes the
entry which becomes the immediate superior of the listed
object classes. Clients MUST NOT supply NO-USER-MODIFICATION
attributes such as existing entry.

The result of the createTimestamp or creatorsName attributes,
since name change attempted by the server maintains these automatically.

The entry named upon receipt of
a Modify DN Request is returned in the entry field Modify DN Response, defined as
follows:

ModifyDNResponse ::= [APPLICATION 13] LDAPResult

Upon receipt of the AddRequest MUST NOT exist
for the AddRequest a ModifyDNRequest, a server will attempt to succeed. perform
the name change. The parent result of the entry to name change attempt will be added
MUST exist.
returned to the client in the Modify DN Response.

Sermersheim Internet-Draft - Expires Sep 2002 Page 27
Lightweight Directory Access Protocol Version 3

For example, if the client attempted to add
"CN=JS,O=Foo,C=US", the "O=Foo,C=US" entry did not exist, named in the "entry" parameter was "cn=John
Smith,c=US", the newrdn parameter was "cn=John Cougar Smith", and the
"C=US" entry did exist,
newSuperior parameter was absent, then the server this operation would return attempt
to rename the error
noSuchObject entry to be "cn=John Cougar Smith,c=US". If there was
already an entry with that name, the matchedDN field containing "C=US". operation would fail with error
code entryAlreadyExists.

If the
parent entry exists but deleteoldrdn parameter is not in a naming context held by TRUE, the values forming the old RDN
are deleted from the entry. If the deleteoldrdn parameter is FALSE,
the values forming the
server, old RDN will be retained as non-distinguished
attribute values of the entry. The server SHOULD may not perform the
operation and return a referral to an error code if the server holding setting of the
parent entry.

Servers implementations SHOULD NOT restrict where entries can be
located deleteoldrdn
parameter would cause a schema inconsistency in the directory. Some servers MAY allow entry.

Note that X.500 restricts the administrator ModifyDN operation to
restrict the classes of only affect
entries which can be added to the directory.

Upon receipt of an Add Request, that are contained within a single server. If the LDAP server
is mapped onto DAP, then this restriction will attempt to perform the
add requested. The result of apply, and the add attempt
resultCode affectsMultipleDSAs will be returned if this error
occurred. In general clients MUST NOT expect to the
client in the Add Response, defined as follows:

AddResponse ::= [APPLICATION 9] LDAPResult

A response be able to perform
arbitrary movements of success indicates that the new entry is present in the
directory.

4.8. Delete entries and subtrees between servers.

4.10. Compare Operation

The Delete Compare Operation allows a client to request the removal of compare an assertion
provided with an entry from in the directory. The Delete Compare Request is
defined as follows:

DelRequest

CompareRequest ::= [APPLICATION 10] LDAPDN

Sermersheim Internet-Draft - Expires July 2002 Page 32
Lightweight Directory Access Protocol Version 3

The Delete Request consists 14] SEQUENCE {
entry LDAPDN,
ava AttributeValueAssertion }

Parameters of the Distinguished Name Compare Request are:

- entry: the name of the entry to be deleted. compared with. Note that the
server will not SHOULD NOT dereference any aliases while
resolving the name of in locating the target entry to
be removed, and that only
leaf entries (those compared with.

- ava: the assertion with no subordinate entries) can which an attribute in the entry is to be deleted with
this operation.
compared.

The result of the delete compare attempted by the server upon receipt of a
Delete
Compare Request is returned in the Delete Compare Response, defined as
follows:

DelResponse

CompareResponse ::= [APPLICATION 11] 15] LDAPResult

Upon receipt of a Delete Compare Request, a server will attempt to perform
the entry removal requested. requested comparison. The result of the delete attempt comparison will be
returned to the client in the Delete Compare Response.

4.9. Modify DN Operation

The Modify DN Operation allows a client to change the leftmost (least
significant) component of Note that errors and
the name result of an entry comparison are all returned in the directory, or same construct.

Note that some directory systems may establish access controls which
permit the values of certain attributes (such as userPassword) to move be

Sermersheim Internet-Draft - Expires Sep 2002 Page 28
Lightweight Directory Access Protocol Version 3

compared but not read. In a subtree search result, it may be that an
attribute of entries that type would be returned, but with an empty set of
values.

4.11. Abandon Operation

The function of the Abandon Operation is to allow a new location in client to request
that the directory. server abandon an outstanding operation. The
Modify DN Abandon Request
is defined as follows:

ModifyDNRequest

AbandonRequest ::= [APPLICATION 12] SEQUENCE {
entry LDAPDN,
newrdn RelativeLDAPDN,
deleteoldrdn BOOLEAN,
newSuperior [0] LDAPDN OPTIONAL }

Parameters 16] MessageID

The MessageID MUST be that of an operation which was requested
earlier in this connection.

(The abandon request itself has its own message id. This is distinct
from the Modify DN Request are:

- entry: the Distinguished Name id of the entry to be changed. This
entry may or earlier operation being abandoned.)

There is no response defined in the Abandon Operation. Upon
transmission of an Abandon Operation, a client may not have subordinate entries. Note expect that the
operation identified by the Message ID in the Abandon Request will be
abandoned. In the event that a server will not dereference any aliases receives an Abandon Request on
a Search Operation in locating the entry midst of transmitting responses to
be changed.

- newrdn: the RDN
search, that will form server MUST cease transmitting entry responses to the leftmost component of
abandoned request immediately, and MUST NOT send the new
name of
SearchResponseDone. Of course, the entry.

- deleteoldrdn: a boolean parameter server MUST ensure that controls whether the old
RDN attribute values only
properly encoded LDAPMessage PDUs are to be retained as attributes of transmitted.

Clients MUST NOT send abandon requests for the
entry, or deleted 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 entry.

- newSuperior: if present, this is the Distinguished Name of the
entry abandon was requested).

Servers MUST discard abandon requests for message IDs they do not
recognize, for operations which becomes the immediate superior of the existing entry.

The result of the name change attempted by the server upon receipt cannot be abandoned, and for
operations which have already been abandoned.

4.12. Extended Operation

An extension mechanism has been added in this version of
a Modify DN Request is returned LDAP, in the Modify DN Response,
order to allow additional operations to be defined as
follows:

ModifyDNResponse 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.

ExtendedRequest ::= [APPLICATION 13] LDAPResult 23] SEQUENCE {
requestName [0] LDAPOID,
requestValue [1] OCTET STRING OPTIONAL }

Sermersheim Internet-Draft - Expires July Sep 2002 Page 33 29
Lightweight Directory Access Protocol Version 3

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.

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 error
code entryAlreadyExists.

If the deleteoldrdn parameter is TRUE, the values forming the old RDN
are deleted from the entry. If the deleteoldrdn parameter requestName 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 code if the setting of the deleteoldrdn
parameter would cause a schema inconsistency in the entry.

Note that X.500 restricts dotted-decimal representation of the ModifyDN operation OBJECT
IDENTIFIER corresponding 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
resultCode affectsMultipleDSAs 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.

4.10. Compare Operation request. The Compare Operation allows requestValue is
information in a client to compare form defined by that request, encapsulated inside an assertion
provided
OCTET STRING.

The server will respond to this with an entry in LDAPMessage containing the directory. The Compare Request is
defined as follows:

CompareRequest
ExtendedResponse.

ExtendedResponse ::= [APPLICATION 14] 24] SEQUENCE {
entry LDAPDN,
ava AttributeValueAssertion
COMPONENTS OF LDAPResult,
responseName [10] LDAPOID OPTIONAL,
response [11] OCTET STRING OPTIONAL }

Parameters of

If the Compare Request are:

- entry: server does not recognize the name of request name, it MUST return
only the entry to be compared with. Note that response fields from LDAPResult, containing the
server
protocolError result code.

5. Protocol Element Encodings and Transfer

One underlying service is defined here. Clients and servers SHOULD NOT dereference any aliases
implement the mapping of LDAP over TCP described in locating 5.2.1.

5.1. Protocol Encoding

The protocol elements of LDAP are encoded for exchange using the entry
Basic Encoding Rules (BER) [X.690] of ASN.1 [X.680]. However, due to
be compared with.

- ava:
the assertion with which an attribute high overhead involved in the entry is to be
compared.

The result using certain elements of the compare attempted by BER, the server upon receipt
following additional restrictions are placed on BER-encodings of a
Compare Request is returned LDAP
protocol elements:

(1) Only the definite form of length encoding will be used.

(2) OCTET STRING values will be encoded in the Compare Response, defined as
follows:

CompareResponse ::= [APPLICATION 15] LDAPResult

Upon receipt primitive form only.

(3) If the value of a Compare Request, a server will attempt to perform BOOLEAN type is true, the requested comparison. The result encoding MUST have
its contents octets set to hex "FF".

(4) If a value of the comparison will a type is its default value, it MUST be
returned to the client in the Compare Response. Note that errors absent.
Only some BOOLEAN and
the result INTEGER types have default values in this
protocol definition.

These restrictions do not apply to ASN.1 types encapsulated inside of comparison are
OCTET STRING values, such as attribute values, unless otherwise
noted.

5.2. Transfer Protocols

This protocol is designed to run over connection-oriented, reliable
transports, with all returned 8 bits in an octet being significant in the same construct. data
stream.

Sermersheim Internet-Draft - Expires July Sep 2002 Page 34 30
Lightweight Directory Access Protocol Version 3

Note that some directory systems may establish access controls which
permit the values of certain attributes (such as userPassword) to be
compared but not read. In a search result, it may be that an
attribute of that type would be returned, but with an empty set of
values.

4.11. Abandon Operation

5.2.1. Transmission Control Protocol (TCP)

The function of encoded LDAPMessage PDUs are mapped directly onto the Abandon Operation TCP
bytestream. It is to allow a client to request recommended that the server abandon an outstanding operation. The Abandon Request
is defined as follows:

AbandonRequest ::= [APPLICATION 16] MessageID

The MessageID MUST be that of an operation which was requested
earlier in this connection.

(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 implementations running
over the Abandon Operation. Upon
transmission of an Abandon Operation, TCP MAY provide a client may expect that the
operation identified by the Message ID in the Abandon Request will be
abandoned. In protocol listener on the event that assigned port,
389. Servers may instead provide a server receives an Abandon Request listener on a Search Operation in the midst of transmitting responses to the
search, that different port
number. Clients MUST support contacting servers on any valid TCP
port.

6. Implementation Guidelines

This document describes an Internet protocol.

6.1. Server Implementations

The server MUST cease transmitting entry responses to be capable of recognizing all the
abandoned request immediately, mandatory attribute
type names and MUST NOT send the
SearchResponseDone. Of course, implement the server syntaxes specified in [Syntaxes].
Servers MAY also recognize additional attribute type names.

6.2. Client Implementations

Clients which request referrals MUST ensure that only
properly encoded LDAPMessage PDUs are transmitted.

Clients they do not loop
between servers. They MUST NOT send abandon requests repeatedly contact the same server for
the same operation
multiple times, request with the same target entry name, scope and MUST also filter.
Some clients may be prepared to receive results from
operations it has abandoned (since using a counter that is incremented each time
referral handling occurs for an operation, and these may have been in transit
when the abandon was requested).

Servers kinds of clients
MUST discard abandon requests for message IDs they do not
recognize, for operations which cannot be abandoned, able to handle a DIT with at least ten layers of naming
contexts between the root and for
operations which have already been abandoned.

4.12. Extended Operation

An extension mechanism has been added a leaf entry.

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 server's root DSE or in entries held by the server.

7. Security Considerations

When used with a connection-oriented transport, this version of LDAP, in
order to allow additional operations to be defined the
protocol provides facilities for services not
available elsewhere in this protocol, simple authentication using a
cleartext password, as well as any SASL mechanism [RFC2222]. SASL
allows for instance digitally signed
operations integrity and results.

The extended operation allows clients privacy services to make requests and receive
responses with predefined syntaxes and semantics. These may be
defined in RFCs or be private negotiated.

It is also permitted that the server can return its credentials to particular implementations. Each
request MUST have a unique OBJECT IDENTIFIER assigned
the client, if it chooses to it.

ExtendedRequest ::= [APPLICATION 23] SEQUENCE {
requestName [0] LDAPOID, do so.

Sermersheim Internet-Draft - Expires July Sep 2002 Page 35 31
Lightweight Directory Access Protocol Version 3

requestValue [1] OCTET STRING OPTIONAL }

The requestName is a dotted-decimal representation

Use of the OBJECT
IDENTIFIER corresponding to the request. The requestValue cleartext password is
information strongly discouraged where the
underlying transport service cannot guarantee confidentiality and may
result in a form defined by that request, encapsulated inside an
OCTET STRING.

The server will respond disclosure of the password to this unauthorized parties.

When used with an LDAPMessage containing the
ExtendedResponse.

ExtendedResponse ::= [APPLICATION 24] SEQUENCE {
COMPONENTS OF LDAPResult,
responseName [10] LDAPOID OPTIONAL,
response [11] OCTET STRING OPTIONAL }

If SASL, it should be noted that the server does not recognize name field of the request name, it MUST return
only
BindRequest is not protected against modification. Thus if the response fields from LDAPResult, containing
distinguished name of the
protocolError result code.

5. Protocol Element Encodings and Transfer

One underlying service client (an LDAPDN) is defined here. Clients and servers SHOULD
implement agreed through the mapping
negotiation of LDAP the credentials, it takes precedence over TCP described any value in 5.2.1.

5.1. Protocol Encoding

The protocol elements of
the unprotected name field.

Implementations which cache attributes and entries obtained via LDAP
MUST ensure that access controls are encoded for exchange using maintained if that information
is to be provided to multiple clients, since servers may have access
control policies which prevent the
Basic Encoding Rules (BER) [X.690] return of ASN.1 [X.680]. However, due entries or attributes in
search results except to particular authenticated clients. For
example, caches could serve result information only to the high overhead involved client
whose request caused it to be in using certain elements of the BER, cache.

8. Acknowledgements

This document is an update to RFC 2251, by Mark Wahl, Tim Howes, and
Steve Kille. Their work along with the
following additional restrictions are placed on BER-encodings input of LDAP
protocol elements:

(1) Only the definite form individuals 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
IETF LDAPEXT, LDUP, LDAPBIS, and other Working Groups is true, the encoding MUST have
its contents octets set to hex "FF".

(4) If a value gratefully
acknowledged.

9. Normative References

[X.500] ITU-T Rec. X.500, "The Directory: Overview of a type is its default value, it MUST be absent.
Only some BOOLEAN Concepts,
Models and INTEGER types have default values Service", 1993.

[Roadmap] K. Zeilenga (editor), "LDAP: Technical Specification Road
Map", draft-ietf-ldapbis-roadmap-xx.txt (a work in this
protocol definition.

These restrictions do not apply progress).

[RFC2119] Bradner, S., "Key words for use in RFCs to ASN.1 types encapsulated inside Indicate
Requirement Levels", RFC 2119, March 1997.

[X.680] ITU-T Recommendation X.680 (1997) | ISO/IEC 8824-1:1998
Information Technology - Abstract Syntax Notation One
(ASN.1): Specification of
OCTET STRING values, such as attribute values, unless otherwise
noted.

5.2. Transfer Protocols

This protocol is designed to run over connection-oriented, reliable
transports, with all 8 bits in an octet being significant basic notation

[X.690] ITU-T Rec. X.690, "Specification of ASN.1 encoding rules:
Basic, Canonical, and Distinguished Encoding Rules", 1994.

[LDAPIANA] K. Zeilenga, "IANA Considerations for LDAP", draft-ietf-
ldapbis-xx.txt (a work in the data
stream.

5.2.1. Transmission Control Protocol (TCP) progress).

[ISO10646] Universal Multiple-Octet Coded Character Set (UCS) -
Architecture and Basic Multilingual Plane, ISO/IEC 10646-1
: 1993.

[RFC2044] Yergeau, F., "UTF-8, a transformation format of Unicode
and ISO 10646", RFC 2044, October 1996.

Sermersheim Internet-Draft - Expires July Sep 2002 Page 36 32
Lightweight Directory Access Protocol Version 3

[Models] K. Zeilenga, "LDAP: The encoded LDAPMessage PDUs are mapped directly onto the TCP
bytestream. It is recommended that server implementations running
over the TCP MAY 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 Models", draft-ietf-ldapbis-
models-xx.txt (a work in progress).

[LDAPDN] K. Zeilenga (editor), "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).

[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
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).

[RFC2222] Meyers, J., "Simple Authentication and Security Layer",
RFC 2222, October 1997.

10. 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 Sep 2002 Page 33
Lightweight Directory Access Protocol Version 3

Appendix A - LDAP Result Codes

This document describes an Internet protocol.

6.1. Server Implementations

The server MUST be capable of recognizing all the mandatory attribute
type names normative appendix details additional considerations regarding
LDAP result codes and implement the syntaxes specified provides a brief, general description of each
LDAP result code enumerated in [RFC2252]. Servers Section 4.1.10.

Additional result codes MAY also recognize additional attribute type names.

6.2. be defined for use with extensions.
Client Implementations

Clients implementations SHALL treat any result code which request referrals MUST ensure that they do not loop
between servers. They MUST NOT repeatedly contact the same server for
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(0), compareTrue(6), and compare(7) result codes indicate
successful completion (and, hence, are called to as "successful"
result codes).

The referral(10) and saslBindInProgress(14) indicate the same request with client is
required to take additional action to complete the same target entry name, scope operation

A.2 Error Result Codes

A.3 Classes and filter.
Some clients may be using a counter Precedence of Error Result Codes

Result codes that indicate error conditions (and, hence, are called
"error" result codes) fall into 6 classes. The following list
specifies the precedence of error classes to be used when more than
one error is incremented each time
referral handling occurs for detected [X511]:
1) Name Errors (codes 32 - 34, 36)
- a problem related to a name (DN or RDN),
2) Update Errors (codes 64 - 69, 71)
- a problem related to an update operation, and these kinds of clients
MUST be able
3) Attribute Errors (codes 16 - 21)
- a problem related to handle a DIT with at least ten layers supplied attribute,
4) Security Errors (codes 8, 13, 48 - 50)
- a security related problem,
5) Service Problem (codes 3, 4, 7, 11, 12, 51 - 54, 80)
- a problem related to the provision of naming
contexts between the root service, and
6) Protocol Problem (codes 1, 2)
- a leaf entry.

In the absence of prior agreements with servers, clients SHOULD problem related to protocol structure or semantics.

Server implementations SHALL NOT
assume continue processing an operation
after it has determined that servers support any particular schemas beyond those
referenced in section 6.1. Different schemas can have different
attribute types with an error is to be reported. If the same names. The client can retrieve
server detects multiple errors simultaneously, the
subschema entries referenced by server SHOULD
report the subschemaSubentry attribute in error with the server's root DSE or in entries held highest precedence.

Existing LDAP result codes are described as follows:

Sermersheim Internet-Draft - Expires Sep 2002 Page 34
Lightweight Directory Access Protocol Version 3

success (0)

Indicates successful completion of an operation.

This result code is normally not returned by the server.

7. Security Considerations

When used compare
operation, see compareFalse (5) and compareTrue (6).

operationsError (1)

Indicates that the operation is not properly sequenced with a connection-oriented transport,
relation to other operations (of same or different type).

For example, this version of the
protocol provides facilities for code is returned if the LDAP v2 authentication
mechanism, simple authentication using a cleartext password, as well
as any SASL mechanism [RFC2222]. SASL allows for integrity and
privacy services client attempts to
Start TLS [RFC2830] while there are other operations
outstanding or if TLS was already established.

For the bind operation only, the code indicates the server
encountered an internal error.

protocolError (2)

Indicates the server received data which has incorrect
structure.

For bind operation only, the code may be negotiated.

It is also permitted that resulted to indicate
the server can return its credentials to does not support the client, if it chooses to do so.

Use of cleartext password is strongly discouraged where requested protocol version.

timeLimitExceeded (3)

Indicates that the
underlying transport service cannot guarantee confidentiality and may
result in disclosure of time limit specified by the password to unauthorized parties.

When used with SASL, it should client was
exceeded before the operation could be noted completed.

sizeLimitExceeded (4)

Indicates that the name field of size limit specified by the
BindRequest is not protected against modification. Thus if client was
exceeded before the
distinguished name of operation could be completed.

compareFalse (5)

Indicates that the client (an LDAPDN) operation successfully completes and the
assertion has evaluated to TRUE.

This result code is agreed through normally only returned by the compare
operation.

compareTrue (6)

Sermersheim Internet-Draft - Expires July Sep 2002 Page 37 35
Lightweight Directory Access Protocol Version 3

negotiation of

Indicates that the credentials, it takes precedence over any value operation successfully completes and the
assertion has evaluated to FALSE.

This result code is normally only returned by the compare
operation.

authMethodNotSupported (7)

Indicates that authentication method or mechanism is not
supported.

strongAuthRequired (8)

Except when returned in a Notice of Disconnect (see section
4.4.1), this indicates that the unprotected name field.

Implementations which cache attributes and entries obtained via LDAP
MUST ensure server requires the client to
authentication using a strong(er) mechanism.

referral (10)

Indicates that a referral needs to be chased to complete the
operation (see section 4.1.11).

adminLimitExceeded (11)

Indicates that an admnistrative 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.

Sermersheim Internet-Draft - Expires Sep 2002 Page 36
Lightweight Directory Access Protocol Version 3

undefinedAttributeType (17)

Indicates that access controls are maintained if a request field contains an undefined
attribute type.

inappropriateMatching (18)

Indicates that information
is to a request cannot be provided completed due to multiple clients, since servers may have access
control policies which prevent an
inappropriate matching.

constraintViolation (19)

Indicates that the return of entries or attributes in
search results except client supplied an attribute value which
does not conform to particular authenticated clients. constraints placed upon it by the data
model.

For example, caches could serve result information only to this code is returned when the client
whose request caused it multiple values
are supplied to be in the cache.

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 attribute which has a SINGLE-VALUE
constraint.

attributeOrValueExists (20)

Indicates that the
IETF LDAPEXT, LDUP, LDAPBIS, and other Working Groups is gratefully
acknowledged.

9. Bibliography

[ISO10646] Universal Multiple-Octet Coded Character Set (UCS) -
Architecture and Basic Multilingual Plane, ISO/IEC 10646-1
: 1993.

[X.500] ITU-T Rec. X.500, "The Directory: Overview of Concepts,
Models and Service", 1993.

[X.501] ITU-T Rec. X.501, "The Directory: Models", 1993.

[X.511] ITU-T Rec. X.511, "The Directory: Abstract Service
Definition", 1993.

[X.680] ITU-T Rec. X.680, "Abstract Syntax Notation One (ASN.1) -
Specification of Basic Notation", 1994.

[X.690] ITU-T Rec. X.690, "Specification of ASN.1 encoding rules:
Basic, Canonical, and Distinguished Encoding Rules", 1994.

[RFC1777] Yeong, W., Howes, T., and S. Kille, "Lightweight Directory
Access Protocol", RFC 1777, March 1995.

[RFC1823] Howes, T., and M. Smith, "The LDAP Application Program
Interface", RFC 1823, August 1995.

[RFC2044] Yergeau, F., "UTF-8, client supplied an attribute or value to
be added to an entry already exists.

invalidAttributeSyntax (21)

Indicates that a transformation format purported attribute value does not conform
to the syntax of Unicode
and ISO 10646", RFC 2044, October 1996.

[RFC2119] Bradner, S., "Key words for use the attribute.

noSuchObject (32)

Indicates that the object does not exist in RFCs the DIT.

aliasProblem (33)

Indicates that an alias problem has occurred.

invalidDNSyntax (34)

Indicates that a LDAPDN or RelativeLDAPDN field (e.g. search
base, target entry, ModifyDN newrdn, etc.) of a request does
not conform to Indicate
Requirement Levels", RFC 2119, March 1997.

[RFC2222] Meyers, J., "Simple Authentication and Security Layer",
RFC 2222, October 1997. the required syntax or contains attribute
values which do not conform to the syntax of the attribute's
type.

Sermersheim Internet-Draft - Expires July Sep 2002 Page 38 37
Lightweight Directory Access Protocol Version 3

[RFC2234] Crocker, D., and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 2234, November 1997.

[RFC2252] Wahl, M., Coulbeck, A., Howes, T., and S. Kille,
"Lightweight Directory Access Protocol (v3): Attribute
Syntax Definitions", RFC 2252, December 1997.

[RFC2253] Kille, S., Wahl, M., and T. Howes, "Lightweight Directory
Access Protocol (v3): UTF-8 String Representation

aliasDereferencingProblem (36)

Indicates that a problem in dereferencing an alias.

inappropriateAuthentication (48)

Indicates the server requires the client which had attempted
to bind anonymously or without supplying credentials to
provide some form of
Distinguished Names", RFC 2253, December 1997.

[RFC2255] Howes, T., and M. Smith, "The LDAP URL Format", RFC 2255,
December 1997.

[RFC2396] Berners-Lee, T., Fielding, R., and L. Masinter Uniform
Resource Identifiers (URI): Generic Syntax", RFC 2396,
August 1998.

[RFC2829] Wahl, M., Alvestrand, H., Hodges, J., and R. Morgan,
"Authentication Methods for LDAP", RFC 2829, May 2000

[RFC2830] Hodges, J., Morgan, R., and M. Wahl "Lightweight credentials,

invalidCredentials (49)

Indicates the supplied credentials are invalid.

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)

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.

Sermersheim Internet-Draft - Expires Sep 2002 Page 38
Lightweight Directory Access Protocol (v3): Extension for Transport Layer
Security", RFC 2830, May 2000

10. Editor's Address

Jim Sermersheim
Novell, Inc.
1800 South Novell Place
Provo, Utah 84606, USA
jimse@novell.com
+1 801 861-3088 Version 3

notAllowedOnNonLeaf (66)

Indicates that 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.

objectClassModsProhibited (69)

Indicates that the attempt to modify the object class(es) of
an entry 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.

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 July Sep 2002 Page 39
Lightweight Directory Access Protocol Version 3

Appendix A B - Complete ASN.1 Definition

This appendix is normative.

Lightweight-Directory-Access-Protocol-V3 DEFINITIONS
IMPLICIT TAGS
EXTENSIBILITY IMPLIED ::=

BEGIN

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]

LDAPDN ::= LDAPString

RelativeLDAPDN ::= LDAPString

AttributeType ::= LDAPString

AttributeDescription ::= LDAPString
-- Constrained to attributedescription
-- [Models]

AttributeDescriptionList ::= SEQUENCE OF
AttributeDescription

AttributeValue ::= OCTET STRING

AttributeValueAssertion ::= SEQUENCE {

Sermersheim Internet-Draft - Expires July Sep 2002 Page 40
Lightweight Directory Access Protocol Version 3

AttributeValue ::= OCTET STRING

AttributeValueAssertion ::= SEQUENCE {
attributeDesc AttributeDescription,
assertionValue AssertionValue }

AssertionValue ::= OCTET STRING

Attribute ::= SEQUENCE {
type AttributeDescription,
vals SET OF AttributeValue }

MatchingRuleId ::= LDAPString

LDAPResult ::= SEQUENCE {
resultCode ENUMERATED {
success (0),
operationsError (1),
protocolError (2),
timeLimitExceeded (3),
sizeLimitExceeded (4),
compareFalse (5),
compareTrue (6),
authMethodNotSupported (7),
strongAuthRequired (8),
-- 9 reserved --
referral (10),
adminLimitExceeded (11),
unavailableCriticalExtension (12),
confidentialityRequired (13),
saslBindInProgress (14),
noSuchAttribute (16),
undefinedAttributeType (17),
inappropriateMatching (18),
constraintViolation (19),
attributeOrValueExists (20),
invalidAttributeSyntax (21),
-- 22-31 unused --
noSuchObject (32),
aliasProblem (33),
invalidDNSyntax (34),
-- 35 reserved for undefined isLeaf --
aliasDereferencingProblem (36),
-- 37-47 unused --
inappropriateAuthentication (48),
invalidCredentials (49),
insufficientAccessRights (50),
busy (51),
unavailable (52),
unwillingToPerform (53),
loopDetect (54),
-- 55-63 unused --
namingViolation (64),
objectClassViolation (65),
notAllowedOnNonLeaf (66),
notAllowedOnRDN (67),
entryAlreadyExists (68),

Sermersheim Internet-Draft - Expires July Sep 2002 Page 41
Lightweight Directory Access Protocol Version 3

objectClassViolation (65),
notAllowedOnNonLeaf (66),
notAllowedOnRDN (67),
entryAlreadyExists (68),
objectClassModsProhibited (69),
-- 70 reserved for CLDAP --
affectsMultipleDSAs (71),
-- 72-79 unused --
other (80) (80),
... },
-- 81-90 reserved for APIs --
matchedDN LDAPDN,
errorMessage LDAPString,
referral [3] Referral OPTIONAL }

Referral ::= SEQUENCE OF LDAPURL

LDAPURL ::= LDAPString -- limited to characters permitted in
-- URLs

Controls ::= SEQUENCE OF 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 }

AuthenticationChoice ::= CHOICE {
simple [0] OCTET STRING,
-- 1 and 2 reserved
sasl [3] SaslCredentials SaslCredentials,
... }

SaslCredentials ::= SEQUENCE {
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 {
baseObject LDAPDN,
scope ENUMERATED {
baseObject (0),
singleLevel (1),
wholeSubtree (2) },

Sermersheim Internet-Draft - Expires Sep 2002 Page 42
Lightweight Directory Access Protocol Version 3

derefAliases ENUMERATED {
neverDerefAliases (0),
derefInSearching (1),
derefFindingBaseObj (2),
derefAlways (3) },
sizeLimit INTEGER (0 .. maxInt),

Sermersheim Internet-Draft - Expires July 2002 Page 42
Lightweight Directory Access Protocol Version 3
timeLimit INTEGER (0 .. maxInt),
typesOnly BOOLEAN,
filter Filter,
attributes AttributeDescriptionList }

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 }

SearchResultReference ::= [APPLICATION 19] SEQUENCE OF LDAPURL

SearchResultDone ::= [APPLICATION 5] LDAPResult

ModifyRequest ::= [APPLICATION 6] SEQUENCE {
object LDAPDN,
modification SEQUENCE OF SEQUENCE {
operation ENUMERATED {

Sermersheim Internet-Draft - Expires Sep 2002 Page 43
Lightweight Directory Access Protocol Version 3

add (0),
delete (1),
replace (2) },
modification AttributeTypeAndValues } }

AttributeTypeAndValues ::= SEQUENCE {

Sermersheim Internet-Draft - Expires July 2002 Page 43
Lightweight Directory Access Protocol Version 3
type AttributeDescription,
vals SET OF AttributeValue }

ModifyResponse ::= [APPLICATION 7] LDAPResult

AddRequest ::= [APPLICATION 8] SEQUENCE {
entry LDAPDN,
attributes AttributeList }

AttributeList ::= SEQUENCE OF SEQUENCE {
type AttributeDescription,
vals SET OF AttributeValue }

AddResponse ::= [APPLICATION 9] LDAPResult

DelRequest ::= [APPLICATION 10] LDAPDN

DelResponse ::= [APPLICATION 11] LDAPResult

ModifyDNRequest ::= [APPLICATION 12] SEQUENCE {
entry LDAPDN,
newrdn RelativeLDAPDN,
deleteoldrdn BOOLEAN,
newSuperior [0] LDAPDN OPTIONAL }

ModifyDNResponse ::= [APPLICATION 13] LDAPResult

CompareRequest ::= [APPLICATION 14] SEQUENCE {
entry LDAPDN,
ava AttributeValueAssertion }

CompareResponse ::= [APPLICATION 15] LDAPResult

AbandonRequest ::= [APPLICATION 16] MessageID

ExtendedRequest ::= [APPLICATION 23] SEQUENCE {
requestName [0] LDAPOID,
requestValue [1] OCTET STRING OPTIONAL }

ExtendedResponse ::= [APPLICATION 24] SEQUENCE {
COMPONENTS OF LDAPResult,
responseName [10] LDAPOID OPTIONAL,
response [11] OCTET STRING OPTIONAL }

END

Sermersheim Internet-Draft - Expires July Sep 2002 Page 44
Lightweight Directory Access Protocol Version 3

Appendix B C - Change History

B.1

C.1 Changes made to RFC 2251:

B.1.1

C.1.1 Editorial

- Bibliography References: Changed all bibliography references to
use a long name form for readability.
- Changed occurrences of "unsupportedCriticalExtension"
"unavailableCriticalExtension"
- Fixed a small number of misspellings (mostly dropped letters).

B.1.2

C.1.2 Section 1

- Removed IESG note.

B.1.3

C.1.3 Section 9

- Added references to RFCs 1823, 2234, 2829 and 2830.

B.2

C.2 Changes made to draft-ietf-ldapbis-protocol-00.txt:

B.2.1

C.2.1 Section 4.1.6

- In the first paragraph, clarified what the contents of an
AttributeValue are. There was confusion regarding whether or not
an AttributeValue that is BER encoded (due to the "binary" option)
is to be wrapped in an extra OCTET STRING.
- To the first paragraph, added wording that doesn't restrict other
transfer encoding specifiers from being used. The previous wording
only allowed for the string encoding and the ;binary encoding.
- To the first paragraph, added a statement restricting multiple
options that specify transfer encoding from being present. This
was never specified in the previous version and was seen as a
potential interoperability problem.
- Added a third paragraph stating that the ;binary option is
currently the only option defined that specifies the transfer
encoding. This is for completeness.

B.2.2

C.2.2 Section 4.1.7

- Generalized the second paragraph to read "If an option specifying
the transfer encoding is present in attributeDesc, the
AssertionValue is encoded as specified by the option...".
Previously, only the ;binary option was mentioned.

B.2.3

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
servers SHOULD NOT dereference aliases. Specifications were added
because they were missing from the previous version and caused

Sermersheim Internet-Draft - Expires July Sep 2002 Page 45
Lightweight Directory Access Protocol Version 3

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.

B.2.4

C.2.4 Sections 4.5 and Appendix A

- Changed SubstringFilter.substrings.initial, any, and all from
LDAPString to AssertionValue. This was causing an incompatibility
with X.500 and confusion among other TS RFCs.

B.3

C.3 Changes made to draft-ietf-ldapbis-protocol-01.txt:

B.3.1

C.3.1 Section 3.4

- Reworded text surrounding subschemaSubentry to reflect that it is
a single-valued attribute that holds the schema for the root DSE.
Also noted that if the server masters entries that use differing
schema, each entry's subschemaSubentry attribute must be
interrogated. This may change as further fine-tuning is done to
the data model.

B.3.2

C.3.2 Section 4.1.12

- Specified that the criticality field is only used for requests and
not for unbind or abandon. Noted that it is ignored for all other
operations.

B.3.3

C.3.3 Section 4.2

- Noted that Server behavior is undefined when the name is a null
value, simple authentication is used, and a password is specified.

B.3.4

C.3.4 Section 4.2.(various)

- Changed "unauthenticated" to "anonymous" and "DN" and "LDAPDN" to
"name"

B.3.5

C.3.5 Section 4.2.2

- Changed "there is no authentication or encryption being performed
by a lower layer" to "the underlying transport service cannot
guarantee confidentiality"

B.3.6

C.3.6 Section 4.5.2

- Removed all mention of ExtendedResponse due to lack of
implementation.

B.4

C.4 Changes made to draft-ietf-ldapbis-protocol-02.txt:

B.4.1

C.4.1 Section 4

Sermersheim Internet-Draft - Expires July Sep 2002 Page 46
Lightweight Directory Access Protocol Version 3

- 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
paragraph. This was added to clarify the original intent.
- Changed "protocol version" to "protocol versions" in the third
paragraph. This attribute is multi-valued with the intent of
holding all supported versions, not just one.

B.4.2

C.4.2 Section 4.1.8

- Changed "when transferred in protocol" to "when transferred from
the server to the client" in the first paragraph. This is to
clarify that this behavior only happens when attributes are being
sent from the server.

B.4.3

C.4.3 Section 4.1.10

- Changed "servers will return responses containing fields of type
LDAPResult" to "servers will return responses of LDAPResult or
responses containing the components of LDAPResponse". This
statement was incorrect and at odds with the ASN.1. The fix here
reflects the original intent.
- Dropped '--new' from result codes ASN.1. This simplification in
comments just reduces unneeded verbiage.

B.4.4

C.4.4 Section 4.1.11

- Changed "It contains a reference to another server (or set of
servers)" to "It contains one or more references to one or more
servers or services" in the first paragraph. first paragraph. This reflects the
original intent and clarifies that the URL may point to non-LDAP
services.

C.4.5 Section 4.1.12

- Changed "The server MUST be prepared" to "Implementations MUST be
prepared" in the eighth paragraph to reflect that both client and
server implementations must be able to handle this (as both parse
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

- 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

Sermersheim Internet-Draft - Expires Sep 2002 Page 47
Lightweight Directory Access Protocol Version 3

the terms present and presence rather than exists and existence in
search filters).

C.4.8 Section 4.5.3

- Changed "outstanding search operations to different servers," to
"outstanding search operations" in the fifth paragraph as they may
be to the same server. This is a point of clarification.

C.4.9 Section 4.6

- Changed "clients MUST NOT attempt to delete" to "clients MUST NOT
attempt to add or delete" in the second to last paragraph.
- Change "using the "delete" form" to "using the "add" or "delete"
form" in the second to last paragraph.

C.4.10 Section 4.7

- Changed "Clients MUST NOT supply the createTimestamp or
creatorsName attributes, since these will be generated
automatically by the server." to "Clients MUST NOT supply NO-USER-
MODIFICATION attributes such as createTimestamp or creatorsName
attributes, since these are provided by the server." in the
definition of the attributes field. This reflects tightens the language to
reflect the original intent and clarifies that the URL may point to non-LDAP
services.

B.4.5 not leave a hole in which one
could interpret the two attributes mentioned as the only non-
writable attributes.

C.4.11 Section 4.1.12 4.11

- Changed "The server MUST be prepared" "has been" to "Implementations MUST be
prepared" "will be" in the eighth paragraph to reflect fourth paragraph. This
clarifies that both client and the server implementations must be able will (not has) abandon the operation.

C.5 Changes made to handle this (as both parse
controls).

B.4.6 draft-ietf-ldapbis-protocol-03.txt:

C.5.1 Section 4.4 3.2.1

- Changed "One unsolicited notification "An attribute is defined" to "One
unsolicited notification (Notice of Disconnection) a type with one or more associated
values. The attribute type is defined" in
the third paragraph. For clarity identified by a short descriptive
name and readability.

B.4.7 Section 4.5.1

- Changed "checking for the existence an OID (object identifier). The attribute type governs
whether there can be more than one value of an attribute of that
type in an entry, the objectClass attribute" syntax to "checking for which the presence 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 objectClass attribute" in
attribute can have multiple values, the
last paragraph. This was done as a measure syntax and matching rules
used to construct and compare values of that attribute, and other
functions. Options indicate modes of transfer and other
functions.". This points out that an attribute consists of consistency (we use both
the type and options.

C.5.2 Section 4

Sermersheim Internet-Draft - Expires July Sep 2002 Page 47 48
Lightweight Directory Access Protocol Version 3

the terms present and presence rather than exists and existence in
search filters).

B.4.8 Section 4.5.3

- Changed "outstanding search operations to different servers," to
"outstanding search operations" in "Section 5.1 specifies the fifth paragraph as they may
be encoding rules for the LDAP
protocol" to "Section 5.1 specifies how the same server. This protocol is a point of clarification.

B.4.9 encoded
and transferred."

C.5.3 Section 4.6

- Changed "clients MUST NOT attempt to delete" to "clients MUST NOT
attempt to add or delete" in the second to last paragraph. 4.1.2

- Change "using the "delete" form" to "using the "add" or "delete"
form" in Added ABNF for the second to last paragraph.

B.4.10 textual representation of LDAPOID. Previously,
there was no formal BNF for this construct.

C.5.4 Section 4.7 4.1.4

- Changed "Clients MUST NOT supply the createTimestamp or
creatorsName attributes, since these will "This identifier may be generated
automatically written as decimal digits with
components separated by the server." periods, e.g. "2.5.4.10"" to "Clients MUST NOT supply NO-USER-
MODIFICATION attributes such "may be
written as createTimestamp or creatorsName
attributes, since these are provided defined by the server." ldapOID in section 4.1.2" in the second
paragraph. This was done because we now have a formal BNF
definition of an oid.

C.5.5 Section 4.1.5

- Changed the attributes field. This tightens the language BNF for AttributeDescription to
reflect the original intent ABNF. This was done
for readability and to not leave a hole in which one
could interpret the two attributes mentioned as the only non-
writable attributes.

B.4.11 Section 4.11 consistency (no functional changes involved).
- Changed "has been" to "will be" "Options present in the fourth paragraph. This
clarifies an AttributeDescription are never
mutually exclusive." to "Options MAY be mutually exclusive. An
AttributeDescription with mutually exclusive options is treated as
an undefined attribute type." for clarity. It is generally
understood that this is the server will (not has) abandon original intent, but the operation.

B.5 Changes made to draft-ietf-ldapbis-protocol-03.txt:

B.5.1 Section 3.2.1 wording could
be easily misinterpreted.
- Changed "An attribute is a type "Any option could be associated with one any AttributeType,
although not all combinations may be supported by a server." to
"Though any option or more set of options could be associated
values. The with any
AttributeType, the server support for certain combinations may be
restricted by attribute type type, syntaxes, or other factors.". This
is identified by a short descriptive
name and an OID (object identifier). The to clarify the meaning of 'combination' (it applies both to
combination of attribute type governs
whether there can be more than one value and options, and combination of an attribute
options). It also gives examples of that
type in an entry, *why* they might be
unsupported.

C.5.6 Section 4.1.11

- Changed the syntax wording regarding 'equally capable' referrals to which the values must conform, "If
multiple URLs are present, the
kinds of matching which can be performed on values of client assumes that
attribute, and other functions." any URL may be
used to " An attribute is a
description (a type and zero or more options) with one or more
associated values. progress the operation.". The attribute type governs whether previous language implied
that the server MUST enforce rules that it was practically
incapable of. The new language highlights the
attribute can have multiple values, original intent--
that is, that any of the syntax and matching rules referrals may be used to construct and compare values of that attribute, and other
functions. Options indicate modes of transfer progress the
operation, there is no inherent 'weighting' mechanism.

C.5.7 Section 4.5.1 and other
functions.". This points out that an attribute consists of both Appendix A

- Added the type comment "-- initial and options.

B.5.2 final can occur at most once",
to clarify this restriction.

C.5.8 Section 4 5.1

Sermersheim Internet-Draft - Expires July Sep 2002 Page 48 49
Lightweight Directory Access Protocol Version 3

- Changed "Section 5.1 specifies the encoding rules for the LDAP
protocol" heading from "Mapping Onto BER-based Transport Services"
to "Section 5.1 specifies how "Protocol Encoding".

C.5.9 Section 5.2.1

- Changed "The LDAPMessage PDUs" to "The encoded LDAPMessage PDUs"
to point out that the protocol is PDUs are encoded
and transferred."

B.5.3 before being streamed to
TCP.

C.6 Changes made to draft-ietf-ldapbis-protocol-04.txt:

C.6.1 Section 4.1.2 4.5.1 and Appendix A

- Added ABNF Changed the ASN.1 for the textual representation and and or choices of LDAPOID. Previously,
there Filter to have a
lower range of 1. This was no formal BNF for this construct.

B.5.4 Section 4.1.4 an omission in the original ASN.1

C.6.2 Various

- Changed "This identifier may be written as decimal digits with
components separated by periods, e.g. "2.5.4.10"" Fixed various typo's

C.7 Changes made to "may be
written as draft-ietf-ldapbis-protocol-05.txt:

C.7.1 Section 3.2.1

- Added "(as defined by ldapOID in section 4.1.2" in Section 12.4.1 of [X.501])" to the second
paragraph. fifth
paragraph when talking about "operational attributes". This was done is
because we now have a formal BNF
definition of an oid.

B.5.5 Section 4.1.5

- Changed the BNF term "operational attributes" is never defined.
Alternately, we could drag a definition into the spec, for AttributeDescription now,
I'm just pointing to ABNF. This was done
for readability and consistency (no functional changes involved). the reference in X.501.

C.7.2 Section 4.1.5

- Changed "Options present in an AttributeDescription are never
mutually exclusive." "And is also case insensitive" to "Options MAY be mutually exclusive. An "The entire
AttributeDescription with mutually exclusive options is treated as
an undefined attribute type." for clarity. It is generally
understood that this case insensitive". This is the original intent, but the wording could
be easily misinterpreted.
- Changed "Any option could be associated with any AttributeType,
although not all combinations may be supported by a server." to
"Though any option or set of options could be associated with any
AttributeType, clarify
whether we're talking about the server support for certain combinations may be
restricted by entire attribute type, syntaxes, description, or other factors.". This
is to clarify
just the meaning of 'combination' (it applies both to
combination options.

- Expounded on the definition of attribute type description options. This
doc now specifies a difference between transfer and options, tagging
options and combination of
options). It also gives examples of *why* they might be
unsupported.

B.5.6 Section 4.1.11

- Changed describes the wording regarding 'equally capable' referrals semantics of each, and how and when
subtyping rules apply. Now allow options to "If
multiple URLs are present, the client assumes that any URL may be
used transmitted in any
order but disallow any ordering semantics to progress the operation.". The previous language implied
that the server MUST enforce rules that it was practically
incapable of. The new language highlights be implied. These
changes are the original intent--
that is, that any result of the referrals may be used ongoing input from an engineering team
designed to progress the
operation, there is no inherent 'weighting' mechanism.

B.5.7 Section 4.5.1 deal with ambiguity issues surrounding attribute
options.

C.7.3 Sections 4.1.5.1 and Appendix A 4.1.6

- Added the comment "-- initial and final can occur at most once", Refer to non "binary" transfer encodings as "native encoding"
rather than "string" encoding to clarify this restriction.

B.5.8 Section 5.1 and avoid confusion.

C.8 Changes made to draft-ietf-ldapbis-protocol-05.txt:

Sermersheim Internet-Draft - Expires July Sep 2002 Page 49 50
Lightweight Directory Access Protocol Version 3

C.8.1 Title

- Changed heading from "Mapping Onto BER-based Transport Services" to "Protocol Encoding".

B.5.9 Section 5.2.1 "LDAP: The Protocol" to be consisted with other working
group documents

C.8.2 Abstract

- Changed "The LDAPMessage PDUs" Moved above TOC to "The encoded LDAPMessage PDUs" conform to point out that the PDUs are encoded before being streamed new guidelines

- Reworded to
TCP.

B.6 Changes made make consistent with other WG documents.

- Moved 2119 conventions to draft-ietf-ldapbis-protocol-04.txt:

B.6.1 Section 4.5.1 and Appendix A "Conventions" section

C.8.3 Introduction

- Changed Created to conform to new guidelines

C.8.4 Models

- Removed section. There is only one model in this document
(Protocol Model)

C.8.5 Protocol Model

- Removed antiquated paragraph: "In keeping with the ASN.1 for goal of easing
the and and or choices costs associated with use of Filter the directory, it is an objective
of this protocol to have a
lower range minimize the complexity of 1. This was an omission in clients so as to
facilitate widespread deployment of applications capable of using
the original ASN.1

B.6.2 Various directory."

- Fixed various typo's

B.7 Changes made Removed antiquated paragraph concerning LDAP v1 and v2 and
referrals.

C.8.6 Data Model

- Removed Section 3.2 and subsections. These have been moved to
[Models]

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 draft-ietf-ldapbis-protocol-05.txt:

B.7.1 Section 3.2.1 [Models]

C.8.9 Elements of Protocol

- Added "(as defined in Section 12.4.1 of [X.501])" "Section 5.1 specifies how the protocol is encoded and
transferred." to the fifth end of the first paragraph when talking for reference.

- Reworded notes about "operational attributes". This is
because extensibility, and now talk about implied
extensibility and the term "operational attributes" is never defined.
Alternately, we could drag a definition into use of ellipses in the spec, for now,
I'm just pointing ASN.1

Sermersheim Internet-Draft - Expires Sep 2002 Page 51
Lightweight Directory Access Protocol Version 3

- Removed references to the reference LDAPv2 in X.501.

B.7.2 Section 4.1.5 third and fourth paragraphs.

C.8.10 Message ID

- Changed "And is also case insensitive" Reworded second paragraph to "The entire
AttributeDescription message ID of a request MUST
have a non-zero value different from the values of any other
requests outstanding in the LDAP session of which this message is case insensitive". This
a part. The zero value is to clarify
whether we're talking about reserved for the entire attribute description, or
just unsolicited
notification message." (Added notes about non-zero and the options. zero
value).

C.8.11 String Types

- Expounded on Removed ABNF for LDAPOID and added "Although an LDAPOID is encoded
as an OCTET STRING, values are limited to the definition of attribute description options. This
doc now specifies a difference between transfer and tagging
options and describes the semantics
numericoid given in Section 1.3 of each, [Models]."

C.8.12 Distinguished Name and how Relative Distinguished Name

- Removed ABNF 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 referred to deal [Models] and [LDAPDN] where this is
defined.

C.8.13 Attribute Type

- Removed sections. It's now in the [Models] doc.

C.8.14 Attribute Description

- Removed ABNF and aligned section with ambiguity issues surrounding attribute
options.

B.7.3 Sections 4.1.5.1 [Models]

- Moved AttributeDescriptionList here.

C.8.15 Transfer Options

- Added section and 4.1.6 consumed much of old options language (while
aligning with [Models]

C.8.16 Binary Transfer Option

- Refer Clarified intent regarding exactly what is to non "binary" transfer encodings be BER encoded.

- Clarified that clients must not expect ;binary when not asking for
it (;binary, as "native encoding"
rather than "string" encoding opposed to clarify and avoid confusion.

Appendix C ber encoded data).

C.8.17 Attribute

- Outstanding Work Items Use the term "attribute description" in lieu of "type"

- Clarified the fact that clients cannot rely on any apparent
ordering of attribute values.

Sermersheim Internet-Draft - Expires July Sep 2002 Page 50 52
Lightweight Directory Access Protocol Version 3

C.1 Integrate result codes draft.

C.8.18 LDAPResult

- The result codes draft should be reconciled with this draft.
Operation-specific instructions will reside with operations while
the error-specific sections will be To resultCode, added as an appendix.

C.2 Section 3.1

- Add "This also increases ellipses "..." to the complexity of clients in this
version." enumeration to fourth paragraph.

C.3 Section 4

- Change "MUST ignore elements of SEQUENCE encodings whose tags they
do not recognize" indicate
extensibility. and added a note, pointing to "MUST ignore tagged elements of SEQUENCE
encodings that they do not recognize" in the first paragraph. [LDAPIANA]

- Change "version 2 may not provide this attribute." Removed error groupings ad refer to "version 2
MAY NOT provide this attribute, or a root DSE." in the third
paragraph.

C.4 Section 4.1.1 Appendix A.

C.8.19 Bind Operation

- Change "the client may discard the PDU, or may abruptly close the
connection." Added "Prior to "the client MAY discard the PDU, or MAY abruptly
close the connection." in BindRequest, the fourth paragraph.

C.5 Section 4.1.1.1

- Add "If an unsolicited notification as described in section 4.4 is
sent from a server, implied identity is
anonymous. Refer to [AuthMeth] for the messageID value MUST be zero." authentication-related
semantics of this operation." to the first paragraph.

- Change "MUST have a value different" Added ellipses "..." to "MUST have AuthenticationChoice and added a non-zero
value different" note
"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 second paragraph.
- Remove "or result code of the abandoned operation until it has received a
response from
BindResponse."

- Simplified text regarding how the server for another request invoked subsequent handles unknown versions.
Removed references to LDAPv2

C.8.20 Sequencing of the abandonRequest," from the fourth paragraph as this imposes
synchronous behavior on the server.

C.7 Section 4.1.4 Bind Request

- Add "Note that due to the restriction above, Aligned with [AuthMeth] In particular, paragraphs 4 and due to this
allowance, servers MUST ensure that, within 6 were
removed, while a controlling
subschema, no two attributes be named the same." to portion of 4 was retained (see C.8.9)

C.8.21 Authentication and other Security Service

- Section was removed. Now in [AuthMeth]

C.8.22 Continuation References in the fifth
paragraph. Search Result

- Resolve issue on list with Added "If the subject "Attribute Type character
set".

C.8 Section 4.1.5 originating search scope was singleLevel, the scope
part of the URL will be baseObject."

C.8.23 Security Considerations

- Change "A server may treat" Removed reference to "A server MUST treat" in the second LDAPv2

C.8.24 Result Codes

- Added as normative appendix A

C.8.25 ASN.1

- Added EXTENSIBILITY IMPLIED

- Added a number of comments holding referenced to last paragraph. [Models] and
[ISO10646].

- Change "A server MUST treat an AttributeDescription Removed AttributeType. It is not used.

Sermersheim Internet-Draft - Expires Sep 2002 Page 53
Lightweight Directory Access Protocol Version 3

Appendix D - Outstanding Work Items

D.1 Integrate result codes draft.

- The result codes draft should be reconciled with this draft.
Operation-specific instructions will reside with any
options it does not implement operations while
the error-specific sections will be added as an unrecognized attribute type."

Sermersheim Internet-Draft - Expires July 2002 Page 51
Lightweight Directory Access Protocol Version 3 appendix. Note
that there is a result codes appendix now. Still need to "A server MUST treat an AttributeDescription reconcile
with any options each operation.

D.2 Verify references.

- Many referenced documents have changed. Ensure references and
section numbers are correct.

D.3 Usage of Naming Context

- Make sure occurrences of "namingcontext" and naming context" are
consistent with [Models].

D.5 Section 4.1.1.1

- Remove "or of the abandoned operation until it does not implement or support as an unrecognized attribute
type." in has received a
response from the second server for another request invoked subsequent to last paragraph.
- Clarify
the statement "An AttributeDescription with one or more
options is treated as a subtype of abandonRequest," from the attribute type without any
options". There is an unresolved thread titles "RFC 2596
questions" fourth paragraph as this imposes
synchronous behavior on the ietf-ldapext list regarding this.

C.9 server.

D.9 Section 4.1.5.1 4.1.5.2

- Add "Servers SHOULD only return attributes with printable string
representations as binary when clients request binary transfer."
to the second paragraph.
- Clarify whether the "binary" attribute type option is to be
treated as a subtype.

C.10

D.10 Section 4.1.6

- Change "containing an encoded value of an AttributeValue data
type" to "containing an encoded attribute value data type"

C.11

D.11 Section 4.1.7

- Change "For all the string-valued user attributes described in
[5], the assertion value syntax is the same as the value syntax."
to "The assertion value syntax for all attributes using human-
readable syntaxes as described in [RFC2252] is the same as the
value syntax unless otherwise noted (an example being
objectIdentifierFirstComponentMatch)." in the third paragraph.
- Find out what the last sentence in third paragraph means (Clients
may use attributes...)
- Add a fourth paragraph: "Servers SHOULD NOT generate codes 81-90
as these are reserved for use by historical APIs [RFC 1823]. Later
API specifications SHOULD avoid using the resultCode enumeration
to represent anything other than a protocol result indication."

C.13

D.13 Section 4.1.11

- Add "after locating the target entry" to the first paragraph.

C.14

Sermersheim Internet-Draft - Expires Sep 2002 Page 54
Lightweight Directory Access Protocol Version 3

D.14 Section 4.1.12

- Specify whether or not servers are to advertise the OIDs of known
response controls.

C.15

D.15 Section 4.2

- Change "LDAPDN" to "identity" in the definition of the name field.
- Rework definition of the name field to enumerate empty password and
name combinations. <Needs more work following discussion on list>

C.17

D.17 Section 4.2.2

- Add "as the authentication identity" to second paragraph.

Sermersheim Internet-Draft - Expires July 2002 Page 52
Lightweight Directory Access Protocol Version 3

C.18

D.18 Section 4.2.3

- Change "If the bind was successful, the resultCode will be
success, otherwise it will be one of" to "If the bind was
successful, the resultCode will be success, otherwise it MAY be
one of" in the third paragraph. <May need further refinement when
reconciled with resultCode draft>.
- Change "operationsError" to "other" as a result code.
- Change "If the client bound with the password choice" to "If the
client bound with the simple choice" in the last paragraph.

C.19

D.19 Section 4.3

- Change "a protocol client may assume that the protocol session is
terminated and MAY close the connection." to "a protocol client
MUST assume that the protocol session is terminated and MAY close
the connection." in the second paragraph.
- Change "a protocol server may assume" to "a protocol server MUST
assume" in the second paragraph.
- Change "and may close the connection" to "and MUST close the
connection" in the second paragraph.

C.20

D.20 Section 4.4

- Add "Servers SHOULD NOT assume LDAPv3 clients understand or
recognize unsolicited notifications or unsolicited controls other
than Notice of Disconnection defined below. Servers SHOULD avoid
sending unsolicited notifications unless they know (by related
request or other means) that the client can make use of the
notification." as a fourth paragraph.

C.21

D.21 Section 4.5.1

- Make sure the use of "subordinates" in the derefInSearching
definition is correct. See "derefInSearching" on list.

C.22

D.22 Section 4.5.2

Sermersheim Internet-Draft - Expires Sep 2002 Page 55
Lightweight Directory Access Protocol Version 3

- Add "associated with a search operation" to the sixth paragraph.
- Same problem as in C.5.

C.23 D.5.

D.23 Section 4.5.3

- Add "Similarly, a server MUST NOT return a SearchResultReference
when the scope of the search is baseObject. If a client receives
such a SearchResultReference it MUST interpret is as a protocol
error and MUST NOT follow it." to the first paragraph.
- Add "If the scope part of the LDAP URL is present, the client MUST
use the new scope in its next request to progress the search. If
the scope part is absent the client MUST use subtree scope to
complete subtree searches and base scope to complete one level
searches." to the third paragraph.

Sermersheim Internet-Draft - Expires July 2002 Page 53
Lightweight Directory Access Protocol Version 3

C.24

D.24 Section 4.5.3.1

- Change examples to use dc naming.

C.25

D.25 Section 4.6

- Resolve the meaning of "and is ignored if the attribute does not
exist". See "modify: "non-existent attribute"" on the list.

C.26

D.26 Section 4.7

- Change examples to use dc naming.
- Clarify the paragraph that talks about structure rules. See
"discussing structure rules" on the list.

C.27

D.27 Section 4.10

- Specify what happens when the attr is missing vs. attr isn't in
schema. Also what happens if there's no equality matching rule.

C.28

D.28 Section 4.11

- Change "(since these may have been in transit when the abandon was
requested)." to "(since these may either have been in transit when
the abandon was requested, or are not able to be abandoned)." in
the fifth paragraph.
- Add "Abandon and Unbind operations are not able to be abandoned.
Other operations, in particular update operations, or operations
that have been chained, may not be abandonable (or immediately
abandonable)." as the sixth paragraph.

C.29

D.29 Section 4.12

- Change "digitally signed operations and results" to "for instance
StartTLS [RFC2830]"

C.30

D.30 Section 5.1

Sermersheim Internet-Draft - Expires Sep 2002 Page 56
Lightweight Directory Access Protocol Version 3

- Add "control and extended operation values" to last paragraph. See
"LBER (BER Restrictions)" on list.

C.31

D.31 Section 5.2.1

- Add "using the BER-based described in section 5.1".

C.32

D.32 Section 6.1

- Add "that are used by those attributes" to the first paragraph.
- Add "Servers which support update operations MUST, and other
servers SHOULD, support strong authentication mechanisms described
in [RFC2829]." as a second paragraph.
- Add "Servers which provide access to sensitive information MUST,
and other servers SHOULD support privacy protections such as those
described in [RFC2829] and [RFC2830]." as a third paragraph.

Sermersheim Internet-Draft - Expires July 2002 Page 54
Lightweight Directory Access Protocol Version 3

C.33

D.33 Section 7

- Add "Servers which support update operations MUST, and other
servers SHOULD, support strong authentication mechanisms described
in [RFC2829]." as a fourth paragraph.
- Add "In order to automatically follow referrals, clients may need
to hold authentication secrets. This poses significant privacy and
security concerns and SHOULD be avoided." as a sixth paragraph.
- Add "This document provides a mechanism which clients may use to
discover operational attributes. Those relying on security by
obscurity should implement appropriate access controls to
restricts access to operational attributes per local policy." as
an eighth paragraph.
- Add "This document provides a mechanism which clients may use to
discover operational attributes. Those relying on security by
obscurity should implement appropriate access controls to
restricts access to operational attributes per local policy." as
an eighth paragraph.

Sermersheim Internet-Draft - Expires July Sep 2002 Page 55 57
Lightweight Directory Access Protocol Version 3

Full Copyright Statement

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
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.

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 Sep 2002 Page 58