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1236 lines
44 KiB
Plaintext
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Network Working Group W. Yeong
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Request for Comments: 1777 Performance Systems International
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Obsoletes: 1487 T. Howes
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Category: Standards Track University of Michigan
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S. Kille
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ISODE Consortium
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March 1995
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Lightweight Directory Access Protocol
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Status of this Memo
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This document specifies an Internet standards track protocol for the
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Internet community, and requests discussion and suggestions for
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improvements. Please refer to the current edition of the "Internet
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Official Protocol Standards" (STD 1) for the standardization state
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and status of this protocol. Distribution of this memo is unlimited.
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Abstract
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The protocol described in this document is designed to provide access
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to the X.500 Directory while not incurring the resource requirements
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of the Directory Access Protocol (DAP). This protocol is specifically
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targeted at simple management applications and browser applications
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that provide simple read/write interactive access to the X.500
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Directory, and is intended to be a complement to the DAP itself.
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Key aspects of LDAP are:
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- Protocol elements are carried directly over TCP or other transport,
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bypassing much of the session/presentation overhead.
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- Many protocol data elements are encoding as ordinary strings (e.g.,
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Distinguished Names).
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- A lightweight BER encoding is used to encode all protocol elements.
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1. History
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The tremendous interest in X.500 [1,2] technology in the Internet has
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lead to efforts to reduce the high "cost of entry" associated with
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use of the technology, such as the Directory Assistance Service [3]
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and DIXIE [4]. While efforts such as these have met with success,
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they have been solutions based on particular implementations and as
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such have limited applicability. This document continues the efforts
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to define Directory protocol alternatives but departs from previous
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efforts in that it consciously avoids dependence on particular
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Yeong, Howes & Kille [Page 1]
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RFC 1777 LDAP March 1995
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implementations.
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2. Protocol Model
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The general model adopted by this protocol is one of clients
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performing protocol operations against servers. In this model, this
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is accomplished by a client transmitting a protocol request
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describing the operation to be performed to a server, which is then
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responsible for performing the necessary operations on the Directory.
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Upon completion of the necessary operations, the server returns a
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response containing any results or errors to the requesting client.
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In keeping with the goal of easing the costs associated with use of
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the Directory, it is an objective of this protocol to minimize the
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complexity of clients so as to facilitate widespread deployment of
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applications capable of utilizing the Directory.
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Note that, although servers are required to return responses whenever
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such responses are defined in the protocol, there is no requirement
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for synchronous behavior on the part of either client or server
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implementations: requests and responses for multiple operations may
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be exchanged by client and servers in any order, as long as clients
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eventually receive a response for every request that requires one.
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Consistent with the model of servers performing protocol operations
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on behalf of clients, it is also to be noted that protocol servers
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are expected to handle referrals without resorting to the return of
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such referrals to the client. This protocol makes no provisions for
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the return of referrals to clients, as the model is one of servers
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ensuring the performance of all necessary operations in the
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Directory, with only final results or errors being returned by
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servers to clients.
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Note that this protocol can be mapped to a strict subset of the
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directory abstract service, so it can be cleanly provided by the DAP.
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3. Mapping Onto Transport Services
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This protocol is designed to run over connection-oriented, reliable
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transports, with all 8 bits in an octet being significant in the data
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stream. Specifications for two underlying services are defined here,
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though others are also possible.
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3.1. Transmission Control Protocol (TCP)
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The LDAPMessage PDUs are mapped directly onto the TCP bytestream.
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Server implementations running over the TCP should provide a protocol
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listener on port 389.
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Yeong, Howes & Kille [Page 2]
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RFC 1777 LDAP March 1995
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3.2. Connection Oriented Transport Service (COTS)
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The connection is established. No special use of T-Connect is made.
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Each LDAPMessage PDU is mapped directly onto T-Data.
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4. Elements of Protocol
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For the purposes of protocol exchanges, all protocol operations are
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encapsulated in a common envelope, the LDAPMessage, which is defined
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as follows:
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LDAPMessage ::=
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SEQUENCE {
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messageID MessageID,
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protocolOp CHOICE {
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bindRequest BindRequest,
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bindResponse BindResponse,
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unbindRequest UnbindRequest,
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searchRequest SearchRequest,
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searchResponse SearchResponse,
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modifyRequest ModifyRequest,
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modifyResponse ModifyResponse,
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addRequest AddRequest,
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addResponse AddResponse,
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delRequest DelRequest,
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delResponse DelResponse,
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modifyRDNRequest ModifyRDNRequest,
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modifyRDNResponse ModifyRDNResponse,
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compareDNRequest CompareRequest,
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compareDNResponse CompareResponse,
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abandonRequest AbandonRequest
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}
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}
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MessageID ::= INTEGER (0 .. maxInt)
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The function of the LDAPMessage is to provide an envelope containing
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common fields required in all protocol exchanges. At this time the
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only common field is a message ID, which is required to have a value
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different from the values of any other requests outstanding in the
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LDAP session of which this message is a part.
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The message ID value must be echoed in all LDAPMessage envelopes
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encapsulting responses corresponding to the request contained in the
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LDAPMessage in which the message ID value was originally used.
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In addition to the LDAPMessage defined above, the following
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definitions are also used in defining protocol operations:
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Yeong, Howes & Kille [Page 3]
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RFC 1777 LDAP March 1995
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LDAPString ::= OCTET STRING
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The LDAPString is a notational convenience to indicate that, although
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strings of LDAPString type encode as OCTET STRING types, the legal
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character set in such strings is limited to the IA5 character set.
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LDAPDN ::= LDAPString
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RelativeLDAPDN ::= LDAPString
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An LDAPDN and a RelativeLDAPDN are respectively defined to be the
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representation of a Distinguished Name and a Relative Distinguished
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Name after encoding according to the specification in [5], such that
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<distinguished-name> ::= <name>
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<relative-distinguished-name> ::= <name-component>
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where <name> and <name-component> are as defined in [5].
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AttributeValueAssertion ::=
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SEQUENCE {
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attributeType AttributeType,
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attributeValue AttributeValue
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}
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The AttributeValueAssertion type definition is similar to the one in
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the X.500 Directory standards.
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AttributeType ::= LDAPString
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AttributeValue ::= OCTET STRING
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An AttributeType value takes on as its value the textual string
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associated with that AttributeType in the X.500 Directory standards.
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For example, the AttributeType 'organizationName' with object
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identifier 2.5.4.10 is represented as an AttributeType in this
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protocol by the string "organizationName". In the event that a
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protocol implementation encounters an Attribute Type with which it
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cannot associate a textual string, an ASCII string encoding of the
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object identifier associated with the Attribute Type may be
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subsitituted. For example, the organizationName AttributeType may be
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represented by the ASCII string "2.5.4.10" if a protocol
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implementation is unable to associate the string "organizationName"
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with it.
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Yeong, Howes & Kille [Page 4]
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RFC 1777 LDAP March 1995
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A field of type AttributeValue takes on as its value an octet string
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encoding of a Directory AttributeValue type. The definition of these
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string encodings for different Directory AttributeValue types may be
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found in companions to this document that define the encodings of
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various attribute syntaxes such as [6].
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LDAPResult ::=
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SEQUENCE {
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resultCode ENUMERATED {
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success (0),
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operationsError (1),
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protocolError (2),
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timeLimitExceeded (3),
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sizeLimitExceeded (4),
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compareFalse (5),
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compareTrue (6),
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authMethodNotSupported (7),
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strongAuthRequired (8),
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noSuchAttribute (16),
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undefinedAttributeType (17),
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inappropriateMatching (18),
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constraintViolation (19),
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attributeOrValueExists (20),
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invalidAttributeSyntax (21),
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noSuchObject (32),
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aliasProblem (33),
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invalidDNSyntax (34),
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isLeaf (35),
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aliasDereferencingProblem (36),
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inappropriateAuthentication (48),
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invalidCredentials (49),
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insufficientAccessRights (50),
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busy (51),
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unavailable (52),
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unwillingToPerform (53),
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loopDetect (54),
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namingViolation (64),
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objectClassViolation (65),
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notAllowedOnNonLeaf (66),
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notAllowedOnRDN (67),
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entryAlreadyExists (68),
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objectClassModsProhibited (69),
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other (80)
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},
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matchedDN LDAPDN,
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errorMessage LDAPString
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}
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Yeong, Howes & Kille [Page 5]
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RFC 1777 LDAP March 1995
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The LDAPResult is the construct used in this protocol to return
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success or failure indications from servers to clients. In response
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to various requests, servers will return responses containing fields
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of type LDAPResult to indicate the final status of a protocol
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operation request. The errorMessage field of this construct may, at
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the servers option, be used to return an ASCII string containing a
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textual, human-readable error diagnostic. As this error diagnostic is
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not standardized, implementations should not rely on the values
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returned. If the server chooses not to return a textual diagnostic,
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the errorMessage field of the LDAPResult type should contain a zero
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length string.
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For resultCodes of noSuchObject, aliasProblem, invalidDNSyntax,
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isLeaf, and aliasDereferencingProblem, the matchedDN field is set to
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the name of the lowest entry (object or alias) in the DIT that was
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matched and is a truncated form of the name provided or, if an alias
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has been dereferenced, of the resulting name. The matchedDN field
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should be set to NULL DN (a zero length string) in all other cases.
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4.1. Bind Operation
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The function of the Bind Operation is to initiate a protocol session
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between a client and a server, and to allow the authentication of the
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client to the server. The Bind Operation must be the first operation
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request received by a server from a client in a protocol session.
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The Bind Request is defined as follows:
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BindRequest ::=
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[APPLICATION 0] SEQUENCE {
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version INTEGER (1 .. 127),
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name LDAPDN,
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authentication CHOICE {
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simple [0] OCTET STRING,
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krbv42LDAP [1] OCTET STRING,
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krbv42DSA [2] OCTET STRING
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}
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}
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Parameters of the Bind Request are:
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- version: A version number indicating the version of the protocol to
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be used in this protocol session. This document describes version
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2 of the LDAP protocol. Note that there is no version negotiation,
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and the client should just set this parameter to the version it
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desires.
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Yeong, Howes & Kille [Page 6]
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RFC 1777 LDAP March 1995
|
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- name: The name of the Directory object that the client wishes to
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bind as. This field may take on a null value (a zero length
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string) for the purposes of anonymous binds.
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- authentication: information used to authenticate the name, if any,
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provided in the Bind Request. The "simple" authentication option
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provides minimal authentication facilities, with the contents of
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the authentication field consisting only of a cleartext password.
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This option should also be used when unauthenticated or anonymous
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binds are to be performed, with the field containing a zero length
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string in such cases. Kerberos version 4 [7] authentication to the
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LDAP server and the DSA is accomplished by using the "krbv42LDAP"
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and "krbv42DSA" authentication options, respectively. Note that
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though they are referred to as separate entities here, there is no
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requirement these two entities be distinct (i.e., a DSA could speak
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LDAP directly). Two separate authentication options are provided
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to support all implementations. Each octet string should contain
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the kerberos ticket (e.g., as returned by krb_mk_req()) for the
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appropriate service. The suggested service name for authentication
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to the LDAP server is "ldapserver". The suggested service name for
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authentication to the DSA is "x500dsa". In both cases, the
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suggested instance name for the service is the name of the host on
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which the service is running. Of course, the actual service names
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and instances will depend on what is entered in the local kerberos
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principle database.
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The Bind Operation requires a response, the Bind Response, which is
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defined as:
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BindResponse ::= [APPLICATION 1] LDAPResult
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A Bind Response consists simply of an indication from the server of
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the status of the client's request for the initiation of a protocol
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session.
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Upon receipt of a Bind Request, a protocol server will authenticate
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the requesting client if necessary, and attempt to set up a protocol
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session with that client. The server will then return a Bind Response
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to the client indicating the status of the session setup request.
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4.2. Unbind Operation
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The function of the Unbind Operation is to terminate a protocol
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session. The Unbind Operation is defined as follows:
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UnbindRequest ::= [APPLICATION 2] NULL
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Yeong, Howes & Kille [Page 7]
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|
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RFC 1777 LDAP March 1995
|
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|
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The Unbind Operation has no response defined. Upon transmission of an
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UnbindRequest, a protocol client may assume that the protocol session
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is terminated. Upon receipt of an UnbindRequest, a protocol server
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may assume that the requesting client has terminated the session and
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that all outstanding requests may be discarded.
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4.3. Search Operation
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The Search Operation allows a client to request that a search be
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performed on its behalf by a server. The Search Request is defined as
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follows:
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SearchRequest ::=
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[APPLICATION 3] SEQUENCE {
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baseObject LDAPDN,
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scope ENUMERATED {
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baseObject (0),
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singleLevel (1),
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wholeSubtree (2)
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},
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derefAliases ENUMERATED {
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neverDerefAliases (0),
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derefInSearching (1),
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derefFindingBaseObj (2),
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derefAlways (3)
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},
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sizeLimit INTEGER (0 .. maxInt),
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timeLimit INTEGER (0 .. maxInt),
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attrsOnly BOOLEAN,
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filter Filter,
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attributes SEQUENCE OF AttributeType
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}
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Filter ::=
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CHOICE {
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and [0] SET OF Filter,
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or [1] SET OF Filter,
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not [2] Filter,
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equalityMatch [3] AttributeValueAssertion,
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substrings [4] SubstringFilter,
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greaterOrEqual [5] AttributeValueAssertion,
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lessOrEqual [6] AttributeValueAssertion,
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present [7] AttributeType,
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approxMatch [8] AttributeValueAssertion
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}
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SubstringFilter
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SEQUENCE {
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Yeong, Howes & Kille [Page 8]
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RFC 1777 LDAP March 1995
|
||
|
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type AttributeType,
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SEQUENCE OF CHOICE {
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initial [0] LDAPString,
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any [1] LDAPString,
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final [2] LDAPString
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}
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}
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Parameters of the Search Request are:
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- baseObject: An LDAPDN that is the base object entry relative to
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which the search is to be performed.
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- scope: An indicator of the scope of the search to be performed. The
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semantics of the possible values of this field are identical to the
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semantics of the scope field in the Directory Search Operation.
|
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- derefAliases: An indicator as to how alias objects should be
|
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handled in searching. The semantics of the possible values of
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this field are, in order of increasing value:
|
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neverDerefAliases: do not dereference aliases in searching
|
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or in locating the base object of the search;
|
||
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derefInSearching: dereference aliases in subordinates of
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the base object in searching, but not in locating the
|
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base object of the search;
|
||
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derefFindingBaseObject: dereference aliases in locating
|
||
the base object of the search, but not when searching
|
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subordinates of the base object;
|
||
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derefAlways: dereference aliases both in searching and in
|
||
locating the base object of the search.
|
||
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||
- sizelimit: A sizelimit that restricts the maximum number of entries
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to be returned as a result of the search. A value of 0 in this
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field indicates that no sizelimit restrictions are in effect for
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the search.
|
||
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- timelimit: A timelimit that restricts the maximum time (in seconds)
|
||
allowed for a search. A value of 0 in this field indicates that no
|
||
timelimit restrictions are in effect for the search.
|
||
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- attrsOnly: An indicator as to whether search results should contain
|
||
both attribute types and values, or just attribute types. Setting
|
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this field to TRUE causes only attribute types (no values) to be
|
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returned. Setting this field to FALSE causes both attribute types
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 9]
|
||
|
||
RFC 1777 LDAP March 1995
|
||
|
||
|
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and values to be returned.
|
||
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||
- filter: A filter that defines the conditions that must be fulfilled
|
||
in order for the search to match a given entry.
|
||
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||
- attributes: A list of the attributes from each entry found as a
|
||
result of the search to be returned. An empty list signifies that
|
||
all attributes from each entry found in the search are to be
|
||
returned.
|
||
|
||
The results of the search attempted by the server upon receipt of a
|
||
Search Request are returned in Search Responses, defined as follows:
|
||
|
||
Search Response ::=
|
||
CHOICE {
|
||
entry [APPLICATION 4] SEQUENCE {
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objectName LDAPDN,
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||
attributes SEQUENCE OF SEQUENCE {
|
||
AttributeType,
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||
SET OF AttributeValue
|
||
}
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||
},
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||
resultCode [APPLICATION 5] LDAPResult
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||
}
|
||
|
||
Upon receipt of a Search Request, a server will perform the necessary
|
||
search of the DIT.
|
||
|
||
The server will return to the client a sequence of responses
|
||
comprised of:
|
||
|
||
- Zero or more Search Responses each consisting of an entry found
|
||
during the search; with the response sequence terminated by
|
||
|
||
- A single Search Response containing an indication of success, or
|
||
detailing any errors that have occurred.
|
||
|
||
Each entry returned will contain all attributes, complete with
|
||
associated values if necessary, as specified in the 'attributes'
|
||
field of the Search Request.
|
||
|
||
Note that an X.500 "list" operation can be emulated by a one-level
|
||
LDAP search operation with a filter checking for the existence of the
|
||
objectClass attribute, and that an X.500 "read" operation can be
|
||
emulated by a base object LDAP search operation with the same filter.
|
||
|
||
|
||
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 10]
|
||
|
||
RFC 1777 LDAP March 1995
|
||
|
||
|
||
4.4. Modify Operation
|
||
|
||
The Modify Operation allows a client to request that a modification
|
||
of the DIB 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 SEQUENCE {
|
||
type AttributeType,
|
||
values SET OF
|
||
AttributeValue
|
||
}
|
||
}
|
||
}
|
||
|
||
Parameters of the Modify Request are:
|
||
|
||
- object: The object to be modified. The value of this field should
|
||
name the object to be modified after all aliases have been
|
||
dereferenced. The server will not perform any alias dereferencing
|
||
in determining the object to be modified.
|
||
|
||
- A list of modifications to be performed on the entry to be modified.
|
||
The entire list of entry modifications should 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 the entire list of modifications is performed
|
||
must conform to the requirements of the Directory schema. The
|
||
values that may be taken on by the 'operation' field in each
|
||
modification construct have the 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
|
||
if all current values of the attribute are listed for
|
||
deletion;
|
||
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 11]
|
||
|
||
RFC 1777 LDAP March 1995
|
||
|
||
|
||
replace: replace existing values of the given attribute
|
||
with the new values listed, creating the attribute if
|
||
necessary.
|
||
|
||
The result of the modify attempted by the server upon receipt of a
|
||
Modify Request is returned in a Modify Response, defined as follows:
|
||
|
||
ModifyResponse ::= [APPLICATION 7] LDAPResult
|
||
|
||
Upon receipt of a Modify Request, a server will perform the necessary
|
||
modifications to the DIB.
|
||
|
||
The server will return to the client a single Modify Response
|
||
indicating either the successful completion of the DIB modification,
|
||
or the reason that the modification failed. Note that due to the
|
||
requirement for atomicity in applying the list of modifications in
|
||
the Modify Request, the client may expect that no modifications of
|
||
the DIB have been performed if the Modify Response received indicates
|
||
any sort of error, and that all requested modifications have been
|
||
performed if the Modify Response indicates successful completion of
|
||
the Modify Operation.
|
||
|
||
4.5. Add Operation
|
||
|
||
The Add Operation allows a client to request the addition of an entry
|
||
into the Directory. The Add Request is defined as follows:
|
||
|
||
AddRequest ::=
|
||
[APPLICATION 8] SEQUENCE {
|
||
entry LDAPDN,
|
||
attrs SEQUENCE OF SEQUENCE {
|
||
type AttributeType,
|
||
values SET OF AttributeValue
|
||
}
|
||
}
|
||
|
||
Parameters of the Add Request are:
|
||
|
||
- entry: the Distinguished Name of the entry to be added. Note that
|
||
all components of the name except for the last RDN component must
|
||
exist for the add to succeed.
|
||
|
||
- attrs: the list of attributes that make up the content of the entry
|
||
being added.
|
||
|
||
The result of the add attempted by the server upon receipt of a Add
|
||
Request is returned in the Add Response, defined as follows:
|
||
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 12]
|
||
|
||
RFC 1777 LDAP March 1995
|
||
|
||
|
||
AddResponse ::= [APPLICATION 9] LDAPResult
|
||
|
||
Upon receipt of an Add Request, a server will attempt to perform the
|
||
add requested. The result of the add attempt will be returned to the
|
||
client in the Add Response.
|
||
|
||
4.6. Delete Operation
|
||
|
||
The Delete Operation allows a client to request the removal of an
|
||
entry from the Directory. The Delete Request is defined as follows:
|
||
|
||
DelRequest ::= [APPLICATION 10] LDAPDN
|
||
|
||
The Delete Request consists only of the Distinguished Name of the
|
||
entry to be deleted. The 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. Note that only leaf
|
||
objects may be deleted with this operation.
|
||
|
||
4.7. Modify RDN Operation
|
||
|
||
The Modify RDN Operation allows a client to change the last component
|
||
of the name of an entry in the Directory. The Modify RDN Request is
|
||
defined as follows:
|
||
|
||
ModifyRDNRequest ::=
|
||
[APPLICATION 12] SEQUENCE {
|
||
entry LDAPDN,
|
||
newrdn RelativeLDAPDN,
|
||
deleteoldrdn BOOLEAN
|
||
}
|
||
|
||
Parameters of the Modify RDN Request are:
|
||
|
||
- entry: the name of the entry to be changed.
|
||
|
||
- newrdn: the RDN that will form the last component of the new name.
|
||
|
||
- deleteoldrdn: a boolean parameter that controls whether the old RDN
|
||
attribute values should be retained as attributes of the entry or
|
||
deleted from the entry.
|
||
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 13]
|
||
|
||
RFC 1777 LDAP March 1995
|
||
|
||
|
||
The result of the name change attempted by the server upon receipt of
|
||
a Modify RDN Request is returned in the Modify RDN Response, defined
|
||
as follows:
|
||
|
||
ModifyRDNResponse ::= [APPLICATION 13] LDAPResult
|
||
|
||
Upon receipt of a Modify RDN Request, 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 RDN Response. The attributes
|
||
that make up the old RDN are deleted from the entry, or kept,
|
||
depending on the setting of the deleteoldrdn parameter.
|
||
|
||
4.8. Compare Operation
|
||
|
||
The Compare Operation allows a client to compare an assertion
|
||
provided with an entry in the Directory. The Compare Request is
|
||
defined as follows:
|
||
|
||
CompareRequest ::=
|
||
[APPLICATION 14] SEQUENCE {
|
||
entry LDAPDN,
|
||
ava AttributeValueAssertion
|
||
}
|
||
|
||
Parameters of the Compare Request are:
|
||
|
||
- entry: the name of the entry to be compared with.
|
||
|
||
- ava: the assertion with which the entry is to be compared.
|
||
|
||
The result of the compare attempted by the server upon receipt of a
|
||
Compare Request is returned in the Compare Response, defined as
|
||
follows:
|
||
|
||
CompareResponse ::= [APPLICATION 15] LDAPResult
|
||
|
||
Upon receipt of a Compare Request, a server will attempt to perform
|
||
the requested comparison. The result of the comparison will be
|
||
returned to the client in the Compare Response. Note that errors and
|
||
the result of comparison are all returned in the same construct.
|
||
|
||
6.9. Abandon Operation
|
||
|
||
The function of the Abandon Operation is to allow a client to request
|
||
that the server abandon an outstanding operation. The Abandon
|
||
Request is defined as follows:
|
||
|
||
AbandonRequest ::= [APPLICATION 16] MessageID
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 14]
|
||
|
||
RFC 1777 LDAP March 1995
|
||
|
||
|
||
There is no response defined in the Abandon Operation. Upon
|
||
transmission of an Abandon Operation, a client may expect that the
|
||
operation identityfied by the Message ID in the Abandon Request has
|
||
been abandoned. In the event that a server receives an Abandon
|
||
Request on a Search Operation in the midst of transmitting responses
|
||
to that search, that server should cease transmitting responses to
|
||
the abandoned search immediately.
|
||
|
||
5. Protocol Element Encodings
|
||
|
||
The protocol elements of LDAP are encoded for exchange using the
|
||
Basic Encoding Rules (BER) [12] of ASN.1 [11]. However, due to the
|
||
high overhead involved in using certain elements of the BER, the
|
||
following additional restrictions are placed on BER-encodings of LDAP
|
||
protocol elements:
|
||
|
||
(1) Only the definite form of length encoding will be used.
|
||
|
||
(2) Bitstrings and octet strings and all character string types
|
||
will be encoded in the primitive form only.
|
||
|
||
6. Security Considerations
|
||
|
||
This version of the protocol provides facilities only for simple
|
||
authentication using a cleartext password, and for kerberos version 4
|
||
authentication. Future versions of LDAP will likely include support
|
||
for other authentication methods.
|
||
|
||
7. Bibliography
|
||
|
||
[1] The Directory: Overview of Concepts, Models and Service. CCITT
|
||
Recommendation X.500, 1988.
|
||
|
||
[2] Information Processing Systems -- Open Systems Interconnection --
|
||
The Directory: Overview of Concepts, Models and Service. ISO/IEC
|
||
JTC 1/SC21; International Standard 9594-1, 1988
|
||
|
||
[3] Rose, M., "Directory Assistance Service", RFC 1202, Performance
|
||
Systems International, Inc., February 1991.
|
||
|
||
[4] Howes, T., Smith, M., and B. Beecher, "DIXIE Protocol
|
||
Specification, RFC 1249, University of Michigan, August 1991.
|
||
|
||
[5] Kille, S., "A String Representation of Distinguished Names", RFC
|
||
1779, ISODE Consortium, March 1995.
|
||
|
||
|
||
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 15]
|
||
|
||
RFC 1777 LDAP March 1995
|
||
|
||
|
||
[6] Howes, T., Kille, S., Yeong, W., and C. Robbins, "Lightweight
|
||
Directory Access Protocol", RFC 1488, University of Michigan,
|
||
ISODE Consortium, Performance Systems International, NeXor Ltd.,
|
||
July 1993.
|
||
|
||
[7] Kerberos Authentication and Authorization System. S.P. Miller,
|
||
B.C. Neuman, J.I. Schiller, J.H. Saltzer; MIT Project Athena
|
||
Documentation Section E.2.1, December 1987.
|
||
|
||
[8] The Directory: Models. CCITT Recommendation X.501 ISO/IEC JTC
|
||
1/SC21; International Standard 9594-2, 1988.
|
||
|
||
[10] The Directory: Abstract Service Definition. CCITT Recommendation
|
||
X.511, ISO/IEC JTC 1/SC21; International Standard 9594-3, 1988.
|
||
|
||
[11] Specification of Abstract Syntax Notation One (ASN.1). CCITT
|
||
Recommendation X.208, 1988.
|
||
|
||
[12] Specification of Basic Encoding Rules for Abstract Syntax
|
||
Notation One (ASN.1). CCITT Recommendation X.209, 1988.
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 16]
|
||
|
||
RFC 1777 LDAP March 1995
|
||
|
||
|
||
10. Authors' Addresses
|
||
|
||
Wengyik Yeong
|
||
PSI Inc.
|
||
510 Huntmar Park Drive
|
||
Herndon, VA 22070
|
||
USA
|
||
|
||
Phone: +1 703-450-8001
|
||
EMail: yeongw@psilink.com
|
||
|
||
|
||
Tim Howes
|
||
University of Michigan
|
||
ITD Research Systems
|
||
535 W William St.
|
||
Ann Arbor, MI 48103-4943
|
||
USA
|
||
|
||
Phone: +1 313 747-4454
|
||
EMail: tim@umich.edu
|
||
|
||
|
||
Steve Kille
|
||
ISODE Consortium
|
||
PO Box 505
|
||
London
|
||
SW11 1DX
|
||
UK
|
||
|
||
Phone: +44-71-223-4062
|
||
EMail: S.Kille@isode.com
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 17]
|
||
|
||
RFC 1777 LDAP March 1995
|
||
|
||
|
||
Appendix A - Complete ASN.1 Definition
|
||
|
||
Lightweight-Directory-Access-Protocol DEFINITIONS IMPLICIT TAGS ::=
|
||
|
||
BEGIN
|
||
|
||
LDAPMessage ::=
|
||
SEQUENCE {
|
||
messageID MessageID,
|
||
-- unique id in request,
|
||
-- to be echoed in response(s)
|
||
protocolOp CHOICE {
|
||
searchRequest SearchRequest,
|
||
searchResponse SearchResponse,
|
||
modifyRequest ModifyRequest,
|
||
modifyResponse ModifyResponse,
|
||
addRequest AddRequest,
|
||
addResponse AddResponse,
|
||
delRequest DelRequest,
|
||
delResponse DelResponse,
|
||
modifyDNRequest ModifyDNRequest,
|
||
modifyDNResponse ModifyDNResponse,
|
||
compareDNRequest CompareRequest,
|
||
compareDNResponse CompareResponse,
|
||
bindRequest BindRequest,
|
||
bindResponse BindResponse,
|
||
abandonRequest AbandonRequest,
|
||
unbindRequest UnbindRequest
|
||
}
|
||
}
|
||
|
||
BindRequest ::=
|
||
[APPLICATION 0] SEQUENCE {
|
||
version INTEGER (1 .. 127),
|
||
-- current version is 2
|
||
name LDAPDN,
|
||
-- null name implies an anonymous bind
|
||
authentication CHOICE {
|
||
simple [0] OCTET STRING,
|
||
-- a zero length octet string
|
||
-- implies an unauthenticated
|
||
-- bind.
|
||
krbv42LDAP [1] OCTET STRING,
|
||
krbv42DSA [2] OCTET STRING
|
||
-- values as returned by
|
||
-- krb_mk_req()
|
||
-- Other values in later versions
|
||
-- of this protocol.
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 18]
|
||
|
||
RFC 1777 LDAP March 1995
|
||
|
||
|
||
}
|
||
}
|
||
|
||
BindResponse ::= [APPLICATION 1] LDAPResult
|
||
|
||
UnbindRequest ::= [APPLICATION 2] NULL
|
||
|
||
SearchRequest ::=
|
||
[APPLICATION 3] SEQUENCE {
|
||
baseObject LDAPDN,
|
||
scope ENUMERATED {
|
||
baseObject (0),
|
||
singleLevel (1),
|
||
wholeSubtree (2)
|
||
},
|
||
derefAliases ENUMERATED {
|
||
neverDerefAliases (0),
|
||
derefInSearching (1),
|
||
derefFindingBaseObj (2),
|
||
alwaysDerefAliases (3)
|
||
},
|
||
sizeLimit INTEGER (0 .. maxInt),
|
||
-- value of 0 implies no sizelimit
|
||
timeLimit INTEGER (0 .. maxInt),
|
||
-- value of 0 implies no timelimit
|
||
attrsOnly BOOLEAN,
|
||
-- TRUE, if only attributes (without values)
|
||
-- to be returned.
|
||
filter Filter,
|
||
attributes SEQUENCE OF AttributeType
|
||
}
|
||
|
||
SearchResponse ::=
|
||
CHOICE {
|
||
entry [APPLICATION 4] SEQUENCE {
|
||
objectName LDAPDN,
|
||
attributes SEQUENCE OF SEQUENCE {
|
||
AttributeType,
|
||
SET OF
|
||
AttributeValue
|
||
}
|
||
},
|
||
resultCode [APPLICATION 5] LDAPResult
|
||
}
|
||
|
||
ModifyRequest ::=
|
||
[APPLICATION 6] SEQUENCE {
|
||
object LDAPDN,
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 19]
|
||
|
||
RFC 1777 LDAP March 1995
|
||
|
||
|
||
modifications SEQUENCE OF SEQUENCE {
|
||
operation ENUMERATED {
|
||
add (0),
|
||
delete (1),
|
||
replace (2)
|
||
},
|
||
modification SEQUENCE {
|
||
type AttributeType,
|
||
values SET OF
|
||
AttributeValue
|
||
}
|
||
}
|
||
}
|
||
|
||
|
||
ModifyResponse ::= [APPLICATION 7] LDAPResult
|
||
|
||
AddRequest ::=
|
||
[APPLICATION 8] SEQUENCE {
|
||
entry LDAPDN,
|
||
attrs SEQUENCE OF SEQUENCE {
|
||
type AttributeType,
|
||
values SET OF AttributeValue
|
||
}
|
||
}
|
||
|
||
AddResponse ::= [APPLICATION 9] LDAPResult
|
||
|
||
DelRequest ::= [APPLICATION 10] LDAPDN
|
||
|
||
DelResponse ::= [APPLICATION 11] LDAPResult
|
||
|
||
ModifyRDNRequest ::=
|
||
[APPLICATION 12] SEQUENCE {
|
||
entry LDAPDN,
|
||
newrdn RelativeLDAPDN -- old RDN always deleted
|
||
}
|
||
|
||
ModifyRDNResponse ::= [APPLICATION 13] LDAPResult
|
||
|
||
CompareRequest ::=
|
||
[APPLICATION 14] SEQUENCE {
|
||
entry LDAPDN,
|
||
ava AttributeValueAssertion
|
||
}
|
||
|
||
CompareResponse ::= [APPLICATION 15] LDAPResult
|
||
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 20]
|
||
|
||
RFC 1777 LDAP March 1995
|
||
|
||
|
||
AbandonRequest ::= [APPLICATION 16] MessageID
|
||
|
||
MessageID ::= INTEGER (0 .. maxInt)
|
||
|
||
LDAPDN ::= LDAPString
|
||
|
||
RelativeLDAPDN ::= LDAPString
|
||
|
||
Filter ::=
|
||
CHOICE {
|
||
and [0] SET OF Filter,
|
||
or [1] SET OF Filter,
|
||
not [2] Filter,
|
||
equalityMatch [3] AttributeValueAssertion,
|
||
substrings [4] SubstringFilter,
|
||
greaterOrEqual [5] AttributeValueAssertion,
|
||
lessOrEqual [6] AttributeValueAssertion,
|
||
present [7] AttributeType,
|
||
approxMatch [8] AttributeValueAssertion
|
||
}
|
||
|
||
LDAPResult ::=
|
||
SEQUENCE {
|
||
resultCode ENUMERATED {
|
||
success (0),
|
||
operationsError (1),
|
||
protocolError (2),
|
||
timeLimitExceeded (3),
|
||
sizeLimitExceeded (4),
|
||
compareFalse (5),
|
||
compareTrue (6),
|
||
authMethodNotSupported (7),
|
||
strongAuthRequired (8),
|
||
noSuchAttribute (16),
|
||
undefinedAttributeType (17),
|
||
inappropriateMatching (18),
|
||
constraintViolation (19),
|
||
attributeOrValueExists (20),
|
||
invalidAttributeSyntax (21),
|
||
noSuchObject (32),
|
||
aliasProblem (33),
|
||
invalidDNSyntax (34),
|
||
isLeaf (35),
|
||
aliasDereferencingProblem (36),
|
||
inappropriateAuthentication (48),
|
||
invalidCredentials (49),
|
||
insufficientAccessRights (50),
|
||
busy (51),
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 21]
|
||
|
||
RFC 1777 LDAP March 1995
|
||
|
||
|
||
unavailable (52),
|
||
unwillingToPerform (53),
|
||
loopDetect (54),
|
||
namingViolation (64),
|
||
objectClassViolation (65),
|
||
notAllowedOnNonLeaf (66),
|
||
notAllowedOnRDN (67),
|
||
entryAlreadyExists (68),
|
||
objectClassModsProhibited (69),
|
||
other (80)
|
||
},
|
||
matchedDN LDAPDN,
|
||
errorMessage LDAPString
|
||
}
|
||
|
||
AttributeType ::= LDAPString
|
||
-- text name of the attribute, or dotted
|
||
-- OID representation
|
||
|
||
AttributeValue ::= OCTET STRING
|
||
|
||
AttributeValueAssertion ::=
|
||
SEQUENCE {
|
||
attributeType AttributeType,
|
||
attributeValue AttributeValue
|
||
}
|
||
|
||
SubstringFilter ::=
|
||
SEQUENCE {
|
||
type AttributeType,
|
||
SEQUENCE OF CHOICE {
|
||
initial [0] LDAPString,
|
||
any [1] LDAPString,
|
||
final [2] LDAPString
|
||
}
|
||
}
|
||
|
||
LDAPString ::= OCTET STRING
|
||
|
||
maxInt INTEGER ::= 65535
|
||
END
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
Yeong, Howes & Kille [Page 22]
|
||
|