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rfc:rfc4876

Network Working Group B. Neal-Joslin, Ed. Request for Comments: 4876 HP Category: Informational L. Howard

                                                                  PADL
                                                             M. Ansari
                                                              Infoblox
                                                              May 2007
                 A Configuration Profile Schema for
     Lightweight Directory Access Protocol (LDAP)-Based Agents

Status of This Memo

 This memo provides information for the Internet community.  It does
 not specify an Internet standard of any kind.  Distribution of this
 memo is unlimited.

Copyright Notice

 Copyright (C) The IETF Trust (2007).

IESG Note

 This RFC is not a candidate for any level of Internet Standard.  The
 IETF disclaims any knowledge of the fitness of this RFC for any
 purpose and in particular notes that the decision to publish is not
 based on IETF review for such things as security, congestion control,
 or inappropriate interaction with deployed protocols.  The RFC Editor
 has chosen to publish this document at its discretion.  Readers of
 this document should exercise caution in evaluating its value for
 implementation and deployment.  See RFC 3932 for more information.

Abstract

 This document consists of two primary components, a schema for agents
 that make use of the Lightweight Directory Access protocol (LDAP) and
 a proposed use case of that schema, for distributed configuration of
 similar directory user agents.  A set of attribute types and an
 object class are proposed.  In the proposed use case, directory user
 agents (DUAs) can use this schema to determine directory data
 location and access parameters for specific services they support.
 In addition, in the proposed use case, attribute and object class
 mapping allows DUAs to reconfigure their expected (default) schema to
 match that of the end user's environment.  This document is intended
 to be a skeleton for future documents that describe configuration of
 specific DUA services.

Neal-Joslin, et al. Informational [Page 1] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

Table of Contents

 1.  Background and Motivation  . . . . . . . . . . . . . . . . . .  3
 2.  General Information  . . . . . . . . . . . . . . . . . . . . .  4
   2.1.  Requirements Notation  . . . . . . . . . . . . . . . . . .  4
   2.2.  Attributes Summary . . . . . . . . . . . . . . . . . . . .  5
   2.3.  Object Classes Summary . . . . . . . . . . . . . . . . . .  5
   2.4.  Common Syntax/Encoding Definitions . . . . . . . . . . . .  5
 3.  Schema Definition  . . . . . . . . . . . . . . . . . . . . . .  6
   3.1.  Attribute Definitions  . . . . . . . . . . . . . . . . . .  6
   3.2.  Class Definition . . . . . . . . . . . . . . . . . . . . .  9
 4.  DUA Implementation Details . . . . . . . . . . . . . . . . . . 10
   4.1.  Interpreting the preferredServerList Attribute . . . . . . 10
   4.2.  Interpreting the defaultServerList Attribute . . . . . . . 11
   4.3.  Interpreting the defaultSearchBase Attribute . . . . . . . 12
   4.4.  Interpreting the authenticationMethod Attribute  . . . . . 13
   4.5.  Interpreting the credentialLevel Attribute . . . . . . . . 15
   4.6.  Interpreting the serviceSearchDescriptor Attribute . . . . 16
   4.7.  Interpreting the attributeMap Attribute  . . . . . . . . . 20
   4.8.  Interpreting the searchTimeLimit Attribute . . . . . . . . 23
   4.9.  Interpreting the bindTimeLimit Attribute . . . . . . . . . 23
   4.10. Interpreting the followReferrals Attribute . . . . . . . . 24
   4.11. Interpreting the dereferenceAliases Attribute  . . . . . . 24
   4.12. Interpreting the profileTTL Attribute  . . . . . . . . . . 24
   4.13. Interpreting the objectclassMap Attribute  . . . . . . . . 25
   4.14. Interpreting the defaultSearchScope Attribute  . . . . . . 27
   4.15. Interpreting the serviceAuthenticationMethod Attribute . . 27
   4.16. Interpreting the serviceCredentialLevel Attribute  . . . . 28
 5.  Binding to the Directory Server  . . . . . . . . . . . . . . . 29
 6.  Security Considerations  . . . . . . . . . . . . . . . . . . . 29
 7.  Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 30
 8.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 30
   8.1.  Registration of Object Classes . . . . . . . . . . . . . . 31
   8.2.  Registration of Attribute Types  . . . . . . . . . . . . . 31
 9.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 33
   9.1.  Normative References . . . . . . . . . . . . . . . . . . . 33
   9.2.  Informative References . . . . . . . . . . . . . . . . . . 34
 Appendix A.  Examples  . . . . . . . . . . . . . . . . . . . . . . 35

Neal-Joslin, et al. Informational [Page 2] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

1. Background and Motivation

 LDAP [RFC4510] has brought about a nearly ubiquitous acceptance of
 the directory server.  Many client applications (DUAs) are being
 created that use LDAP directories for many different services.  And
 although the LDAP protocol has eased the development of these
 applications, some challenges still exist for both developers and
 directory administrators.
 The authors of this document are implementers of DUAs described by
 [RFC2307].  In developing these agents, we felt there were several
 issues that still need to be addressed to ease the deployment and
 configuration of a large network of these DUAs.
 One of these challenges stems from the lack of a utopian schema.  A
 utopian schema would be one that every application developer could
 agree upon and that would support every application.  Unfortunately
 today, many DUAs define their own schema, even when they provide
 similar services (like RFC 2307 vs. Microsoft's Services for Unix
 [MSSFU]).  These schemas contain similar attributes, but use
 different attribute names.  This can lead to data redundancy within
 directory entries and cause directory administrators unwanted
 challenges, updating schemas and synchronizing data.  Or, in a more
 common case, two or more applications may agree on common schema
 elements, but choose a different schema for other elements of data
 that might also be shareable between the applications.  While data
 synchronization and translation tools exist, the authors of this
 document believe there is value in providing this capability in the
 directory user agent itself.
 Aside from proposing a schema for general use, one goal of this
 document is to eliminate data redundancy by having DUAs configure
 themselves to the schema of the deployed directory, instead of
 forcing the DUA's own schema on the directory.
 Another goal of this document is to provide the DUA with enough
 configuration information so that it can discover how to retrieve its
 data in the directory, such as what locations to search in the
 directory tree.
 Finally, this document intends to describe a configuration method for
 DUAs that can be shared among many DUAs on various platforms,
 providing, as such, a configuration profile.  The purpose of this
 profile is to centralize and simplify management of DUAs.
 This document is intended to provide the skeleton framework for
 future documents that will describe the individual implementation
 details for the particular services provided by that DUA.  The

Neal-Joslin, et al. Informational [Page 3] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 authors of this document plan to develop such a document for the
 Network Information Service DUA, described by RFC 2307 or its
 successor.
 We expect that as DUAs take advantage of this configuration scheme,
 each DUA will require additional configuration parameters, not
 specified by this document.  Thus, we would expect that new auxiliary
 object classes that contain new configuration attributes will be
 created and then joined with the structural class defined by this
 document to create a configuration profile for a particular DUA
 service.  By joining various auxiliary object classes for different
 DUA services, the configuration of various DUA services can be
 controlled by a single configuration profile entry.

2. General Information

 The schema defined by this document is defined under the "DUA
 Configuration Schema".  This schema is derived from the object
 identifier (OID): iso (1) org (3) dod (6) internet (1) private (4)
 enterprises (1) Hewlett-Packard Company (11) directory (1) LDAP-UX
 Integration Project (3) DUA Configuration Schema (1).  This OID is
 represented in this document by the keystring "DUAConfSchemaOID"
 (1.3.6.1.4.1.11.1.3.1).

2.1. Requirements Notation

 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
 document are to be interpreted as described in [RFC2119].

Neal-Joslin, et al. Informational [Page 4] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

2.2. Attributes Summary

 The following attributes are defined in this document:
 preferredServerList
 defaultServerList
 defaultSearchBase
 defaultSearchScope
 authenticationMethod
 credentialLevel
 serviceSearchDescriptor
 serviceCredentialLevel
 serviceAuthenticationMethod
 attributeMap
 objectclassMap
 searchTimeLimit
 bindTimeLimit
 followReferrals
 dereferenceAliases
 profileTTL

2.3. Object Classes Summary

 The following object class is defined in this document:
 DUAConfigProfile

2.4. Common Syntax/Encoding Definitions

 The proposed string encodings used by the attributes defined in this
 document can be found in Section 4.  This document makes use of ABNF
 [RFC4234] for defining new encodings.
 The following syntax definitions are used throughout this document.

Neal-Joslin, et al. Informational [Page 5] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

                    The list of used syntaxes are:
 +---------------------------+---------------------------------------+
 | Key                       | Source                                |
 +---------------------------+---------------------------------------+
 | keystring                 | as defined by [RFC4512] Section 1.4   |
 | descr                     | as defined by [RFC4512] Section 1.4   |
 | SP                        | as defined by [RFC4512] Section 1.4   |
 | WSP                       | as defined by [RFC4512] Section 1.4   |
 | base                      | as defined by distinguishedName in    |
 |                           | [RFC4514]                             |
 | distinguishedName         | as defined by [RFC4514] Section 2     |
 | relativeDistinguishedName | as defined by [RFC4514] Section 2     |
 | scope                     | as defined by [RFC4516] Section 2     |
 | host                      | as defined by [RFC3986] Section 3.2.2 |
 | hostport                  | host [":" port ]                      |
 | port                      | as defined by [RFC3986] Section 3.2.3 |
 | serviceID                 | same as keystring                     |
 +---------------------------+---------------------------------------+
 This document does not define new syntaxes that must be supported by
 the directory server.  Instead, these syntaxes are merely expected to
 be interpreted by the DUA.  As referenced in the schema definition in
 Section 3, most encodings are expected to be stored in attributes
 using common syntaxes, such as the Directory String syntax, as
 defined in Section 3.3.6 of [RFC4517].  Refer to RFC 4517 for
 additional syntaxes used by this schema.

3. Schema Definition

 This section defines a proposed schema.  This schema does not require
 definition of new matching rules or syntaxes, and it may be used for
 any purpose seen.  A proposed use of this schema to support elements
 of configuration of a directory user agent is described in Section 4.

3.1. Attribute Definitions

 This section contains attribute definitions used by agents.  The
 syntax used to describe these attributes is defined in [RFC4512],
 Section 4.1.2.  Individual syntaxes and matching rules used within
 these descriptions are described in [RFC4517], Sections 3.3 and 4.2,
 respectively.

Neal-Joslin, et al. Informational [Page 6] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 ( 1.3.6.1.4.1.11.1.3.1.1.0 NAME 'defaultServerList'
   DESC 'List of default servers'
   EQUALITY caseIgnoreMatch
   SUBSTR caseIgnoreSubstringsMatch
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
   SINGLE-VALUE )
 ( 1.3.6.1.4.1.11.1.3.1.1.1 NAME 'defaultSearchBase'
   DESC 'Default base for searches'
   EQUALITY distinguishedNameMatch
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.12
   SINGLE-VALUE )
 ( 1.3.6.1.4.1.11.1.3.1.1.2 NAME 'preferredServerList'
   DESC 'List of preferred servers'
   EQUALITY caseIgnoreMatch
   SUBSTR caseIgnoreSubstringsMatch
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
   SINGLE-VALUE )
 ( 1.3.6.1.4.1.11.1.3.1.1.3 NAME 'searchTimeLimit'
   DESC 'Maximum time an agent or service allows for a
   search to complete'
   EQUALITY integerMatch
   ORDERING integerOrderingMatch
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
   SINGLE-VALUE )
 ( 1.3.6.1.4.1.11.1.3.1.1.4 NAME 'bindTimeLimit'
   DESC 'Maximum time an agent or service allows for a
   bind operation to complete'
   EQUALITY integerMatch
   ORDERING integerOrderingMatch
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
   SINGLE-VALUE )
 ( 1.3.6.1.4.1.11.1.3.1.1.5 NAME 'followReferrals'
   DESC 'An agent or service does or should follow referrals'
   EQUALITY booleanMatch
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
   SINGLE-VALUE )

Neal-Joslin, et al. Informational [Page 7] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 ( 1.3.6.1.4.1.11.1.3.1.1.6 NAME 'authenticationMethod'
   DESC 'Identifies the types of authentication methods either
   used, required, or provided by a service or peer'
   EQUALITY caseIgnoreMatch
   SUBSTR caseIgnoreSubstringsMatch
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
   SINGLE-VALUE )
 ( 1.3.6.1.4.1.11.1.3.1.1.7 NAME 'profileTTL'
   DESC 'Time to live, in seconds, before a profile is
   considered stale'
   EQUALITY integerMatch
   ORDERING integerOrderingMatch
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
   SINGLE-VALUE )
 ( 1.3.6.1.4.1.11.1.3.1.1.9 NAME 'attributeMap'
   DESC 'Attribute mappings used, required, or supported by an
   agent or service'
   EQUALITY caseIgnoreIA5Match
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )
 ( 1.3.6.1.4.1.11.1.3.1.1.10 NAME 'credentialLevel'
   DESC 'Identifies type of credentials either used, required,
   or supported by an agent or service'
   EQUALITY caseIgnoreIA5Match
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.26
   SINGLE-VALUE )
 ( 1.3.6.1.4.1.11.1.3.1.1.11 NAME 'objectclassMap'
   DESC 'Object class mappings used, required, or supported by
   an agent or service'
   EQUALITY caseIgnoreIA5Match
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )
 ( 1.3.6.1.4.1.11.1.3.1.1.12 NAME 'defaultSearchScope'
   DESC 'Default scope used when performing a search'
   EQUALITY caseIgnoreIA5Match
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.26
   SINGLE-VALUE )

Neal-Joslin, et al. Informational [Page 8] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 ( 1.3.6.1.4.1.11.1.3.1.1.13 NAME 'serviceCredentialLevel'
   DESC 'Specifies the type of credentials either used, required,
   or supported by a specific service'
   EQUALITY caseIgnoreIA5Match
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )
 ( 1.3.6.1.4.1.11.1.3.1.1.14 NAME 'serviceSearchDescriptor'
   DESC 'Specifies search descriptors required, used, or
   supported by a particular service or agent'
   EQUALITY caseExactMatch
   SUBSTR caseExactSubstringsMatch
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 )
 ( 1.3.6.1.4.1.11.1.3.1.1.15 NAME 'serviceAuthenticationMethod'
   DESC 'Specifies types authentication methods either
   used, required, or supported by a particular service'
   EQUALITY caseIgnoreMatch
   SUBSTR caseIgnoreSubstringsMatch
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 )
 ( 1.3.6.1.4.1.11.1.3.1.1.16 NAME 'dereferenceAliases'
   DESC 'Specifies if a service or agent either requires,
   supports, or uses dereferencing of aliases.'
   EQUALITY booleanMatch
   SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
   SINGLE-VALUE )

3.2. Class Definition

 The object class below is constructed from the attributes defined in
 Section 3.1, with the exception of the "cn" attribute, which is
 defined in [RFC4519]. "cn" is used to represent the name of the DUA
 configuration profile and is recommended for the relative
 distinguished name (RDN) [RFC4514] naming attribute.  This object
 class is used specifically by the DUA described in Section 4.  The
 syntax used to describe this object class is defined in [RFC4512],
 Section 4.1.1.

Neal-Joslin, et al. Informational [Page 9] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 ( 1.3.6.1.4.1.11.1.3.1.2.5 NAME 'DUAConfigProfile'
   SUP top STRUCTURAL
   DESC 'Abstraction of a base configuration for a DUA'
   MUST ( cn )
   MAY ( defaultServerList $ preferredServerList $
         defaultSearchBase $ defaultSearchScope $
         searchTimeLimit $ bindTimeLimit $
         credentialLevel $ authenticationMethod $
         followReferrals $ dereferenceAliases $
         serviceSearchDescriptor $ serviceCredentialLevel $
         serviceAuthenticationMethod $ objectclassMap $
         attributeMap $ profileTTL ) )

4. DUA Implementation Details

 This section describes an implementation of the schema described in
 Section 3.  Details about how a DUA should format and interpret the
 defined attributes are described below.  Agents that make use of the
 DUAConfigProfile object class are expected to follow the
 specifications in this section.
 Note: Many of the subsections below contain examples.  Unless
 otherwise specified, these examples are rendered using the LDAP Data
 Interchange Format (LDIF) [RFC2849].

4.1. Interpreting the preferredServerList Attribute

 Interpretation:
    As described by the syntax, the preferredServerList parameter is a
    whitespace-separated list of server addresses and associated port
    numbers.  When the DUA needs to contact a directory server agent
    (DSA), the DUA MUST first attempt to contact one of the servers
    listed in the preferredServerList attribute.  The DUA MUST contact
    the DSA specified by the first server address in the list.  If
    that DSA is unavailable, the remaining DSAs MUST be queried in the
    order provided (left to right) until a connection is established
    with a DSA.  Once a connection with a DSA is established, the DUA
    SHOULD NOT attempt to establish a connection with the remaining
    DSAs.  The purpose of enumerating multiple DSAs is not for
    supplemental data, but for high availability of replicated data.
    This is also the main reason why an LDAP URL [RFC3986] syntax was
    not selected for this document.
    If the DUA is unable to contact any of the DSAs specified by the
    preferredServerList, the defaultServerList attribute MUST be
    examined, as described in Section 4.2.  The servers identified by

Neal-Joslin, et al. Informational [Page 10] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

    the preferredServerList MUST be contacted before attempting to
    contact any of the servers specified by the defaultServerList.
 Syntax:
    serverList = hostport *(SP [hostport])
 Default Value:
    The preferredServerList attribute does not have a default value.
    Instead a DUA MUST examine the defaultServerList attribute.
 Other attribute notes:
    This attribute is used in conjunction with the defaultServerList
    attribute.  Please see Section 4.2 for additional implementation
    notes.  Determining how the DUA should query the DSAs also depends
    on the additional configuration attributes, credentialLevel,
    serviceCredentialLevel, bindTimeLimit,
    serviceAuthenticationMethod, and authenticationMethod.  Please
    review Section 5 for details on how a DUA should properly bind to
    a DSA.
 Example:
       preferredServerList: 192.168.169.170 ldap1.mycorp.com
         ldap2:1389 [1080::8:800:200C:417A]:389

4.2. Interpreting the defaultServerList Attribute

 Interpretation:
    The defaultServerList attribute MUST only be examined if the
    preferredServerList attribute is not provided, or the DUA is
    unable to establish a connection with any of the DSAs specified by
    the preferredServerList.
    If more than one address is provided, the DUA may choose either to
    accept the order provided or to create its own order, based on
    what the DUA determines is the "best" order of DSAs to query.  For
    example, the DUA may choose to examine the server list and to
    query the DSAs in order based on the "closest" server or the
    server with the least amount of "load".  Interpretation of the
    "best" server order is entirely up to the DUA, and not part of
    this document.
    Once the order of server addresses is determined, the DUA contacts
    the DSA specified by the first server address in the list.  If

Neal-Joslin, et al. Informational [Page 11] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

    that DSA is unavailable, the remaining DSAs SHOULD be queried
    until an available DSA is found, or no more DSAs are available.
    If a server address or port is invalid, the DUA SHOULD proceed to
    the next server address as described just above.
 Syntax:
    serverList = hostport *(SP [hostport])
 Default Value:
    If a defaultServerList attribute is not provided, the DUA MAY
    attempt to contact the same DSA that provided the configuration
    profile entry itself.  The default DSA is contacted only if the
    preferredServerList attribute is also not provided.
 Other attribute notes:
    This attribute is used in conjunction with the preferredServerList
    attribute.  Please see Section 4.1 for additional implementation
    notes.  Determining how the DUA should query the DSAs also depends
    on the additional configuration attributes, credentialLevel,
    serviceCredentialLevel, bindTimeLimit,
    serviceAuthenticationMethod, and authenticationMethod.  Please
    review Section 5 for details on how a DUA should properly contact
    a DSA.
 Example:
       defaultServerList: 192.168.169.170 ldap1.mycorp.com
         ldap2:1389 [1080::8:800:200C:417A]:5912

4.3. Interpreting the defaultSearchBase Attribute

 Interpretation:
    When a DUA needs to search the DSA for information, this attribute
    provides the base for the search.  This parameter can be
    overridden or appended by the serviceSearchDescriptor attribute.
    See Section 4.6.
 Syntax:
    Defined by OID 1.3.6.1.4.1.1466.115.121.1.12 [RFC4517].

Neal-Joslin, et al. Informational [Page 12] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 Default Value:
    There is no default value for the defaultSearchBase.  A DUA MAY
    define its own method for determining the search base, if the
    defaultSearchBase is not provided.
 Other attribute notes:
    This attribute is used in conjunction with the
    serviceSearchDescriptor attribute.  See Section 4.6.
 Example:
       defaultSearchBase: dc=mycompany,dc=com

4.4. Interpreting the authenticationMethod Attribute

 Interpretation:
    The authenticationMethod attribute defines an ordered list of LDAP
    bind methods to be used when attempting to contact a DSA.  The
    serviceAuthenticationMethod overrides this value for a particular
    service (see Section 4.15).  Each method MUST be attempted in the
    order provided by the attribute, until a successful LDAP bind is
    performed ("none" is assumed to always be successful).  However,
    the DUA MAY skip over one or more methods.  See Section 5 for more
    information.
    none   - The DUA does not perform an LDAP bind.
    simple - The DUA performs an LDAP simple bind.
    sasl   - The DUA performs an LDAP Simple Authentication and
             Security Layer (SASL) [RFC4422] bind using the specified
             SASL mechanism and options.
    tls    - The DUA performs an LDAP StartTLS operation followed by
             the specified bind method (for more information refer to
             Section 4.14 of [RFC4511]).

Neal-Joslin, et al. Informational [Page 13] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 Syntax:
    authMethod  = method *(";" method)
    method      = none / simple / sasl / tls
    none        = "none"
    simple      = "simple"
    sasl        = "sasl/" saslmech [ ":" sasloption ]
    sasloption  = "auth-conf" / "auth-int"
    tls         = "tls:" (none / simple / sasl)
    saslmech    = SASL mechanism name as defined in [SASLMECH]
    Note: Although multiple authentication methods may be specified in
    the syntax, at most one of each type is allowed.  That is,
    "simple;simple" is invalid.
 Default Value:
    If the authenticationMethod or serviceAuthenticationMethod (for
    that particular service) attributes are not provided, the DUA MAY
    choose to bind to the DSA using any method defined by the DUA.
    However, if either authenticationMethod or
    serviceAuthenticationMethod is provided, the DUA MUST only use the
    methods specified.
 Other attribute notes:
    When using TLS, the string "tls:sasl/EXTERNAL" implies that both
    client and server (DSA and DUA) authentications are to be
    performed.  Any other TLS authentication method implies server-
    only (DSA side credential) authentication, along with the other
    SASL method used for DUA-side authentication.
    Determining how the DUA should bind to the DSAs also depends on
    the additional configuration attributes, credentialLevel,
    serviceCredentialLevel, serviceAuthenticationMethod, and
    bindTimeLimit.  Please review Section 5 for details on how to
    properly bind to a DSA.

Neal-Joslin, et al. Informational [Page 14] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 Example:
    authenticationMethod: tls:simple;sasl/DIGEST-MD5
    (see [RFC2831])

4.5. Interpreting the credentialLevel Attribute

 Interpretation:
    The credentialLevel attribute defines what type(s) of
    credential(s) the DUA MUST use when contacting the DSA.  The
    serviceCredentialLevel overrides this value for a particular
    service (Section 4.16).  The credentialLevel can contain more than
    one credential type, separated by whitespace.
    anonymous The DUA SHOULD NOT use a credential when binding to the
              DSA.
    proxy     The DUA SHOULD use a known proxy identity when binding
              to the DSA.  A proxy identity is a specific credential
              that was created to represent the DUA.  This document
              does not define how the proxy user should be created, or
              how the DUA should determine what the proxy user's
              credential is.  This functionality is up to each
              implementation.
    self      When the DUA is acting on behalf of a known identity,
              the DUA MUST attempt to bind to the DSA as that
              identity.  The DUA should contain methods to determine
              the identity of the user such that the identity can be
              authenticated by the directory server using the defined
              authentication methods.
    If the credentialLevel contains more than one credential type, the
    DUA MUST use the credential types in the order specified.
    However, the DUA MAY skip over one or more credential types.  As
    soon as the DUA is able to successfully bind to the DSA, the DUA
    SHOULD NOT attempt to bind using the remaining credential types.

Neal-Joslin, et al. Informational [Page 15] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 Syntax:
    credentialLevel   = level *(SP level)
    level             = self / proxy / anonymous
    self              = "self"
    proxy             = "proxy"
    anonymous         = "anonymous"
    Note: Although multiple credential levels may be specified in the
    syntax, at most one of each type is allowed.  Refer to
    implementation notes in Section 5 for additional syntax
    requirements for the credentialLevel attribute.
 Default Value:
    If the credentialLevel attribute is not defined, the DUA SHOULD
    NOT use a credential when binding to the DSA (also known as
    anonymous).
 Other attribute notes:
    Determining how the DUA should bind to the DSAs also depends on
    the additional configuration attributes, authenticationMethod,
    serviceAuthenticationMethod, serviceCredentialLevel, and
    bindTimeLimit.  Please review Section 5 for details on how to
    properly bind to a DSA.
 Example:
       credentialLevel: proxy anonymous

4.6. Interpreting the serviceSearchDescriptor Attribute

 Interpretation:
    The serviceSearchDescriptor attribute defines how and where a DUA
    SHOULD search for information for a particular service.  The
    serviceSearchDescriptor contains a serviceID, followed by one or
    more base-scope-filter triples.  These base-scope-filter triples
    are used to define searches only for the specific service.
    Multiple base-scope-filters allow the DUA to search for data in
    multiple locations in the directory information tree (DIT).
    Although this syntax is very similar to the LDAP URL [RFC3986],
    this document requires the ability to supply multiple hosts as

Neal-Joslin, et al. Informational [Page 16] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

    part of the configuration of the DSA.  In addition, an ordered
    list of search descriptors is required, which cannot be specified
    by the LDAP URL.
    The serviceSearchDescriptor might also contain the DN of an entry
    that will contain an alternate profile.  The DSA SHOULD re-
    evaluate the alternate profile and perform searches as specified
    by that profile.
    If the base, as defined in the serviceSearchDescriptor, is
    followed by the "," (ASCII 0x2C) character, this base is known as
    a relative base.  This relative base may be constructed of one or
    more RDN components.  In this case, the DUA MUST define the search
    base by appending the relative base with the defaultSearchBase.
 Syntax:
    serviceSearchList = serviceID ":" serviceSearchDesc *(";"
                        serviceSearchDesc)
    serviceSearchDesc = confReferral / searchDescriptor
    searchDescriptor  = [base] ["?" [scopeSyntax] ["?" [filter]]]
    confReferral      = "ref:" distinguishedName
    base              = distinguishedName / relativeBaseName
    relativeBaseName  = 1*(relativeDistinguishedName ",")
    filter            = UTF-8 encoded string
    If the confReferral, base, relativeBaseName, or filter contains
    the ";" (ASCII 0x3B), "?"  (ASCII 0x3F), """ (ASCII 0x22), or "\"
    (ASCII 0x5C) characters, those characters MUST be escaped
    (preceded by the "\" character).  Alternately, the DN may be
    surrounded by quotes (ASCII 0x22).  Refer to RFC 4514.  If the
    confReferral, base, relativeBaseName, or filter are surrounded by
    quotes, only the """ character needs to be escaped.  Any character
    that does not need to be escaped, and yet is preceded by the "\"
    character, results in both the "\" character and the character
    itself.
    The usage and syntax of the filter string MUST be defined by the
    DUA service.  A suggested syntax would be that defined by
    [RFC4515].

Neal-Joslin, et al. Informational [Page 17] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

    If a DUA is performing a search for a particular service that has
    a serviceSearchDescriptor defined, the DUA MUST set the base,
    scope, and filter as defined.  Each base-scope-filter triple
    represents a single LDAP search operation.  If multiple base-
    scope-filter triples are provided in the serviceSearchDescriptor,
    the DUA SHOULD perform multiple search requests, and in that case,
    it MUST be in the order specified by the serviceSearchDescriptor.
    FYI: Service search descriptors do not exactly follow the LDAP URL
    syntax [RFC4516].  The reasoning for this difference is to
    separate the host name(s) from the filter.  This allows the DUA to
    have a more flexible solution in choosing its DSA.
 Default Value:
    If a serviceSearchDescriptor, or an element thereof, is not
    defined for a particular service, the DUA SHOULD create the base,
    scope, and filter as follows:
    base   - Same as the defaultSearchBase.
    scope  - Same as the defaultSearchScope.
    filter - Use defaults as defined by DUA's service.
    If the defaultSearchBase or defaultSearchScope is not defined,
    then the DUA service MAY use its own default.
 Other attribute notes:
    If a serviceSearchDescriptor exists for a given service, the
    service MUST use at least one base-scope-filter triple in
    performing searches.  It SHOULD perform multiple searches per
    service if multiple base-scope-filter triples are defined for that
    service.
    The details of how the "filter" is interpreted by each DUA's
    service is defined by that service.  This means the filter is NOT
    REQUIRED to be a legal LDAP filter [RFC4515].  Furthermore,
    determining how attribute and object class mapping affects that
    search filter MUST be defined by the service.  That is, the DUA
    SHOULD specify if the attributes in the filter are assumed to
    already have been mapped, or if it is expected that attribute
    mapping (see Section 4.7) would be applied to the filter.  In
    general practice, implementation and usability suggests that
    attribute and object class mapping (Sections 4.7 and 4.13) SHOULD
    NOT be applied to the filter defined in the
    serviceSearchDescriptor.

Neal-Joslin, et al. Informational [Page 18] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

    The serviceID is unique to a given service within the scope of any
    DUA that might use the given profile, and should be defined by
    that service.  Registration of serviceIDs is not addressed by this
    document.  However, as per the guidance at the end of Section 1,
    when DUA developers define their use of the DUAConfigProfile
    schema, they will define the serviceIDs used by that DUA.
    searchGuide and enhancedSearchGuide [RFC4517]:
    There are a few reasons why the authors chose not to take
    advantage of the existing searchGuide and enhancedSearchGuide
    attributes and related syntaxes.  While the enhancedSearchGuide
    met a number of the serviceSearchDescriptor requirements,
    serviceSearchDescriptor was developed primarily to support
    associating search operations with services.  Multiple services
    could be configured using the same profile, thus requiring the
    serviceID to be specified together with the search descriptor
    information.  A few other reasons for not using
    enhancedSearchGuide include:
       The need to specify alternate search bases, including the
       ability to specify search bases that are relative to the parent
       defaultSearchBase.
       The need to specify alternate profiles using the "ref:" syntax.
       The ability for individual services to specify their own
       syntaxes for the format of the search filter.
       The authors' belief that the user community is more familiar
       with the search filter syntax described by RFC 4515 than with
       that described by the enhancedSearchGuide syntax.
 Example:
       defaultSearchBase: dc=mycompany,dc=com
       serviceSearchDescriptor: email:ou=people,ou=org1,?
        one;ou=contractor,?one;
        ref:cn=profile,dc=mycompany,dc=com
    In this example, the DUA MUST search in
    "ou=people,ou=org1,dc=mycompany,dc=com" first.  The DUA then
    SHOULD search in "ou=contractor,dc=mycompany,dc=com", and finally
    it SHOULD search other locations as specified in the profile
    described at "cn=profile,dc=mycompany,dc=com".  For more examples,
    see Appendix A.

Neal-Joslin, et al. Informational [Page 19] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

4.7. Interpreting the attributeMap Attribute

 Interpretation:
    A DUA SHOULD perform attribute mapping for all LDAP operations
    performed for a service that has an attributeMap entry.  Because
    attribute mapping is specific to each service within the DUA, a
    "serviceID" is required as part of the attributeMap syntax.  That
    is, not all DUA services should necessarily perform the same
    attribute mapping.
    Attribute mapping in general is expected to be used to map
    attributes of similar syntaxes as specified by the service
    supported by the DUA.  However, a DUA is NOT REQUIRED to verify
    syntaxes of mapped attributes.  If the DUA does discover that the
    syntax of the mapped attribute does not match that of the original
    attribute, the DUA MAY perform translation between the original
    syntax and the new syntax.  When DUAs do support attribute value
    translation, the method and list of capable translations SHOULD be
    documented in a description of the DUA service.
 Syntax:
    attributeMap      = serviceID ":" origAttribute "=" attributes
    origAttribute     = attribute
    attributes        = wattribute *( SP wattribute )
    wattribute        = WSP newAttribute WSP
    newAttribute      = descr / "*NULL*"
    attribute         = descr
    Values of the origAttribute are defined by and SHOULD be
    documented for the DUA service, as a list of known supported
    attributes.
 Default Value:
    By default, attributes that are used by a DUA service are not
    mapped unless mapped by the attributeMap attributes.  The DUA
    SHOULD NOT map an attribute unless it is explicitly defined by an
    attributeMap attribute.

Neal-Joslin, et al. Informational [Page 20] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 Other attribute notes:
    When an attribute is mapped to the special keystring "*NULL*", the
    DUA SHOULD NOT request that attribute from the DSA, when
    performing a search or compare request.  If the DUA is also
    capable of performing modification on the DSA, the DUA SHOULD NOT
    attempt to modify any attribute which has been mapped to "*NULL*".
    It is assumed the serviceID is unique to a given service within
    the scope of the DSA.
    A DUA SHOULD support attribute mapping.  If it does, the following
    additional rules apply:
    1.  The list of attributes that are allowed to be mapped SHOULD be
        defined by and documented for the service.
    2.  Any supported translation of mapping from attributes of
        dissimilar syntax SHOULD also be defined and documented.
    3.  If an attribute may be mapped to multiple attributes, the DSA
        SHOULD define a syntax or usage statement for how the new
        attribute value will be constructed.  Furthermore, the
        resulting translated syntax of the combined attributes MUST be
        the same as the attribute being mapped.
    4.  A DUA MUST support mapping of attributes using the attribute
        OID.  It SHOULD support attribute mapping based on the
        attribute name.
    5.  It is recommended that attribute mapping not be applied to
        parents of the target entries.
    6.  Attribute mapping is not recursive.  In other words, if an
        attribute has been mapped to a target attribute, that new
        target attribute MUST NOT be mapped to a third attribute.
    7.  A given attribute MUST only be mapped once for a given
        service.
 Example:
    Suppose a DUA is acting on behalf of an email service.  By default
    the "email" service uses the "mail", "cn", and "sn" attributes to
    discover mail addresses.  However, the email service has been
    deployed in an environment that uses "employeeName" instead of
    "cn".  Also, instead of using the "mail" attribute for email
    addresses, the "email" attribute is used.  In this case, the

Neal-Joslin, et al. Informational [Page 21] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

    attribute "cn" can be mapped to "employeeName", allowing the DUA
    to perform searches using the "employeeName" attribute as part of
    the search filter, instead of "cn".  Also, "mail" can be mapped to
    "email" when attempting to retrieve the email address.  This
    mapping is performed by adding the attributeMap attributes to the
    configuration profile entry as follows (represented in LDIF
    [RFC2849]):
                  attributeMap: email:cn=employeeName
                  attributeMap: email:mail=email
 As described above, the DUA MAY also map a single attribute to
 multiple attributes.  When mapping a single attribute to more than
 one attribute, the new syntax or usage of the mapped attribute must
 be intrinsically defined by the DUAs service.
               attributeMap: email:cn=firstName lastName
 In the above example, the DUA creates the new value by generating a
 space-separated string using the values of the mapped attributes.  In
 this case, a special mapping must be defined so that a proper search
 filter can be created.  For further information on this example,
 please refer to Appendix A.
    Another possibility for multiple attribute mapping might come in
    when constructing returned attributes.  For example, perhaps all
    email addresses are of a guaranteed syntax of "uid@domain".  In
    this example, the uid and domain are separate attributes in the
    directory.  The email service may define that if the "mail"
    attribute is mapped to two different attributes, it will construct
    the email address as a concatenation of the two attributes (uid
    and domain), placing the "@" character between them.
                  attributeMap: email:mail=uid domain
 Note: The attributeMap attribute contains only a list of attribute
 names that should be mapped, not the definition of how syntax
 translation should be performed.  The process used to perform
 attribute value syntax translation (such as translating a uid to a
 DN) and/or joining of multiple attribute values to form the target
 syntax (such as in the above email example) is up to the service.
 The attribute list defined in the attributeMap merely provides the
 attributes that would be used as inputs to the translation function
 provided by the service.

Neal-Joslin, et al. Informational [Page 22] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

4.8. Interpreting the searchTimeLimit Attribute

 Interpretation:
    The searchTimeLimit attribute defines the maximum time, in
    seconds, that the DUA SHOULD allow for a search request to
    complete.
 Syntax:
    Defined by OID 1.3.6.1.4.1.1466.115.121.1.27 [RFC4517].
 Default Value:
    If the searchTimeLimit attribute is not defined or is zero, the
    searchTimeLimit SHOULD NOT be enforced by the DUA.
 Other attribute notes:
    This time limit only includes the amount of time required to
    perform the LDAP search operation.  If other operations are
    required, they do not need to be considered part of the search
    time.  See bindTimeLimit for the LDAP bind operation.

4.9. Interpreting the bindTimeLimit Attribute

 Interpretation:
    The bindTimeLimit attribute defines the maximum time, in seconds,
    that a DUA SHOULD allow for the bind request to complete when
    performed against each server on the preferredServerList or
    defaultServerList.
 Syntax:
    Defined by OID 1.3.6.1.4.1.1466.115.121.1.27.
 Default Value:
    If the bindTimeLimit attribute is not defined or is zero, the
    bindTimeLimit SHOULD NOT be enforced by the DUA.
 Other attribute notes:
    This time limit only includes the amount of time required to
    perform the LDAP bind operation.  If other operations are
    required, those operations do not need to be considered part of
    the bind time.  See searchTimeLimit for the LDAP search operation.

Neal-Joslin, et al. Informational [Page 23] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

4.10. Interpreting the followReferrals Attribute

 Interpretation:
    If set to TRUE, the DUA SHOULD follow any referrals if discovered.
    If set to FALSE, the DUA MUST NOT follow referrals.
 Syntax:
    Defined by OID 1.3.6.1.4.1.1466.115.121.1.7 [RFC4517].
 Default Value:
    If the followReferrals attribute is not set or set to an invalid
    value, the default value is TRUE.

4.11. Interpreting the dereferenceAliases Attribute

 Interpretation:
    If set to TRUE, the DUA SHOULD enable alias dereferencing.
    If set to FALSE, the DUA MUST NOT enable alias dereferencing.
 Syntax:
    Defined by OID 1.3.6.1.4.1.1466.115.121.1.7.
 Default Value:
    If the dereferenceAliases attribute is not set or set to an
    invalid value, the default value is TRUE.

4.12. Interpreting the profileTTL Attribute

 Interpretation:
    The profileTTL attribute defines how often the DUA SHOULD reload
    and reconfigure itself using the corresponding configuration
    profile entry.  The value is represented in seconds.  Once a DUA
    reloads the profile entry, it SHOULD reconfigure itself with the
    new values.
 Syntax:
    Defined by OID 1.3.6.1.4.1.1466.115.121.1.27.

Neal-Joslin, et al. Informational [Page 24] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 Default Value:
    If not specified, the DUA MAY use its own reconfiguration policy.
 Other attribute notes:
    If the profileTTL value is zero, the DUA SHOULD NOT automatically
    reload the configuration profile.

4.13. Interpreting the objectclassMap Attribute

 Interpretation:
    A DUA MAY perform object class mapping for all LDAP operations
    performed for a service that has an objectclassMap entry.  Because
    object class mapping is specific for each service within the DUA,
    a "serviceID" is required as part of the objectclassMap syntax.
    That is, not all DUA services should necessarily perform the same
    object class mapping.
    Object class mapping SHOULD be used in conjunction with attribute
    mapping to map the schema required by the service to an equivalent
    schema that is available in the directory.
    Object class mapping may or may not be required by a DUA.  Often,
    the objectclass attribute is used in search filters.  Section 4.7
    recommends that attribute mapping not be applied to the
    serviceSearchDescriptor.  Thus, if the default object classes are
    not used in a DUA deployment, typically only the
    serviceSearchDescriptor needs to be defined to reflect that
    mapping.  However, when the service search descriptor is not
    provided, and the default search filter for that service contains
    the objectclass attribute, that search filter SHOULD be redefined
    by object class mapping, if defined.  If a default search filter
    is not used, it SHOULD be redefined through the
    serviceSearchDescriptor.  If a serviceSearchDescriptor is defined
    for a particular service, it SHOULD NOT be remapped by either the
    objectclassMap or attributeMap values.
    One condition where the objectclassMap SHOULD be used is when the
    DUA is providing gateway functionality.  In this case, the DUA is
    acting on behalf of another service, which may pass in a search
    filter itself.  In this type of DUA, the DUA may alter the search
    filter according to the appropriate attributeMap and
    objectclassMap values.  In this case, it is also assumed that a
    serviceSearchDescriptor is not defined.

Neal-Joslin, et al. Informational [Page 25] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 Syntax:
    objectclassMap    = serviceID ":" origObjectclass "=" objectclass
    origObjectclass   = objectclass
    objectclass       = keystring
    Values of the origObjectclass depend on the type of DUA Service
    using the object class mapping feature.
 Default Value:
    The DUA MUST NOT remap an object class unless it is explicitly
    defined by an objectclassMap attribute.
 Other attribute notes:
    A DUA SHOULD support object class mapping.  If it does, the DUA
    MUST support mapping of object classes using the objectclass OID.
    It SHOULD support object class mapping based on the object class
    name.
    It is assumed the serviceID is unique to a given service within
    the scope of the DSA.
 Example:
    Suppose a DUA is acting on behalf of an email service.  By default
    the "email" service uses the "mail", "cn", and "sn" attributes to
    discover mail addresses in entries created using inetOrgPerson
    object class [RFC2789].  However, the email service has been
    deployed in an environment that uses entries created using
    "employee" object class.  In this case, the attribute "cn" can be
    mapped to "employeeName", and "inetOrgPerson" can be mapped to
    "employee", allowing the DUA to perform LDAP operations using the
    entries that exist in the directory.  This mapping is performed by
    adding attributeMap and objectclassMap attributes to the
    configuration profile entry as follows (represented in LDIF
    [RFC2849]):
              attributeMap: email:cn=employeeName
              objectclassMap: email:inetOrgPerson=employee

Neal-Joslin, et al. Informational [Page 26] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

4.14. Interpreting the defaultSearchScope Attribute

 Interpretation:
    When a DUA needs to search the DSA for information, this attribute
    provides the "scope" for the search.  This parameter can be
    overridden by the serviceSearchDescriptor attribute.  See
    Section 4.6.
 Syntax:
    scopeSyntax = "base" / "one" / "sub"
 Default Value:
    The default value for the defaultSearchScope SHOULD be defined by
    the DUA service.  If the default search scope for a service is not
    defined, then the scope SHOULD be for the DUA to perform a subtree
    search.

4.15. Interpreting the serviceAuthenticationMethod Attribute

 Interpretation:
    The serviceAuthenticationMethod attribute defines an ordered list
    of LDAP bind methods to be used when attempting to contact a DSA
    for a particular service.  Interpretation and use of this
    attribute is the same as Section 4.4, but specific for each
    service.
 Syntax:
    svAuthMethod = serviceID ":" method *(";" method)
    Note: Although multiple authentication methods may be specified in
    the syntax, at most one of each type is allowed.
 Default Value:
    If the serviceAuthenticationMethod attribute is not provided, the
    authenticationMethod SHOULD be followed, or its default.
 Other attribute notes:
    Determining how the DUA should bind to the DSAs also depends on
    the additional configuration attributes, credentialLevel,
    serviceCredentialLevel, and bindTimeLimit.  Please review
    Section 5 for details on how to properly bind to a DSA.

Neal-Joslin, et al. Informational [Page 27] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 Example:
       serviceAuthenticationMethod: email:tls:simple;sasl/DIGEST-MD5

4.16. Interpreting the serviceCredentialLevel Attribute

 Interpretation:
    The serviceCredentialLevel attribute defines what type(s) of
    credential(s) the DUA SHOULD use when contacting the DSA for a
    particular service.  Interpretation and use of this attribute are
    the same as Section 4.5.
 Syntax:
    svCredentialLevel = serviceID ":" level *(SP level)
    Refer to implementation notes in Section 5 for additional syntax
    requirements for the credentialLevel attribute.
    Note: Although multiple credential levels may be specified in the
    syntax, at most one of each type is allowed.
 Default Value:
    If the serviceCredentialLevel attribute is not defined, the DUA
    MUST examine the credentialLevel attribute, or if one is not
    provided, the DUA must follow its default.
 Other attribute notes:
    Determining how the DUA should bind to the DSAs also depends on
    the additional configuration attributes,
    serviceAuthenticationMethod, authenticationMethod, and
    bindTimeLimit.  Please review Section 5 for details on how to
    properly bind to a DSA.
 Example:
       serviceCredentialLevel: email:proxy anonymous

Neal-Joslin, et al. Informational [Page 28] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

5. Binding to the Directory Server

 The DUA SHOULD use the following algorithm when binding to the
 server:
 for (clevel in credLevel) [see Note 1]
   if (clevel is "anonymous")
     for (host in hostnames) [see Note 2]
       if (server is responding)
         return success
     return failure
   else
     for (amethod in authMethod) [see Note 3]
       if (amethod is none)
         for (host in hostnames)
           if (server is responding)
             return success
         return failure
       else
         for (host in hostnames)
           authenticate using amethod and clevel
           if (authentication passed)
             return success
 return failure
 Note 1:   The credLevel is a list of credential levels as defined in
           serviceCredentialLevel (Section 4.16) for a given service.
           If the serviceCredentialLevel is not defined, the DUA MUST
           examine the credentialLevel attribute.
 Note 2:   hostnames is the list of servers to contact as defined in
           Sections 4.1 and 4.2.
 Note 3:   The authMethod is a list of authentication methods as
           defined in serviceAuthenticationMethod (Section 4.15) for a
           given service.  If the serviceAuthenticationMethod is not
           defined, the DUA MUST examine the authenticationMethod
           attribute.

6. Security Considerations

 The profile entries MUST be protected against unauthorized
 modification.  Each service needs to consider implications of
 providing its service configuration as part of this profile and limit
 access to the profile entries accordingly.

Neal-Joslin, et al. Informational [Page 29] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 The management of the authentication credentials for the DUA is
 outside the scope of this document and needs to be handled by the
 DUA.
 Since the DUA needs to know how to properly bind to the directory
 server, the access control configuration of the DSA MUST assure that
 the DSA can view all the elements of the DUAConfigProfile attributes.
 For example, if the credentialLevel attribute contains "Self", but
 the DSA is unable to access the credentialLevel attribute, the DUA
 will instead attempt an anonymous connection to the directory server.
 The algorithm described by Section 5 also has security
 considerations.  Altering that design will alter the security aspects
 of the configuration profile.
 At times, DUAs connect to multiple directory servers in order to
 support potential high-availability and/or performance requirements.
 As such, each directory server specified in the preferredServer list
 and defaultServerList MUST contain the same (replicated) data and be
 part of the same security domain.  This means the directory-supported
 authentication methods, authentication policies, and access control
 policies for directory data are exactly the same across all the
 defined directory servers.

7. Acknowledgments

 There were several additional authors of this document.  However, we
 chose to represent only one author per company in the heading.  From
 Sun, we would like to acknowledge Roberto Tam for his design work on
 Sun's first LDAP name service product and his input for this
 document.  From Hewlett-Packard, we'd like to acknowledge Dave Binder
 for his work architecting Hewlett-Packard's LDAP name service product
 as well as his design guidance on this document.  We'd also like to
 acknowledge Grace Lu from HP, for her input and implementation of
 HP's configuration profile manager code.

8. IANA Considerations

 This document defines new LDAP attributes and an object class for
 object identifier descriptors.  As specified by Section 3.4 and
 required by Section 4 of [RFC4520], this document registers new
 descriptors as follows per the Expert Review.

Neal-Joslin, et al. Informational [Page 30] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

8.1. Registration of Object Classes

 Subject:  Request for LDAP Descriptor Registration
 Descriptor (short name): DUAConfigProfile
 Object Identifier:  1.3.6.1.4.1.11.1.3.1.2.5
 Person & email address to contact for further information:
    See "Author/Change Controller"
 Usage: object class
 Specification: RFC 4876
 Author/Change Controller:
    Bob Neal-Joslin
    Hewlett-Packard Company
    19420 Homestead RD
    Cupertino, CA 95014
    USA
    Phone: +1 408-447-3044
    EMail: bob_joslin@hp.com
 Comments:
    See also the associated request for the defaultServerList,
    defaultSearchBase, preferredServerList, searchTimeLimit,
    bindTimeLimit, followReferrals, authenticationMethod,
    profileTTL, attributeMap, credentialLevel, objectclassMap,
    defaultSearchScope, serviceCredentialLevel,
    serviceSearchDescriptor, serviceAuthenticationMethod, and
    dereferenceAliases attribute types.

8.2. Registration of Attribute Types

 Subject:  Request for LDAP Descriptor Registration
 Descriptor (short name):  See comments
 Object Identifier:  See comments
 Person & email address to contact for further information:
    See "Author/Change Controller"
 Usage:  attribute type

Neal-Joslin, et al. Informational [Page 31] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 Specification: RFC 4876
 Author/Change Controller:
    Bob Neal-Joslin
    Hewlett-Packard Company
    19420 Homestead RD
    Cupertino, CA 95014
    USA
    Phone: +1 408-447-3044
    EMail: bob_joslin@hp.com
 Comments:
    The following object identifiers and associated attribute
    types have been registered.
      OID                           Attribute Type
      --------------------------    ---------------------------
      1.3.6.1.4.1.11.1.3.1.1.0      defaultServerList
      1.3.6.1.4.1.11.1.3.1.1.1      defaultSearchBase
      1.3.6.1.4.1.11.1.3.1.1.2      preferredServerList
      1.3.6.1.4.1.11.1.3.1.1.3      searchTimeLimit
      1.3.6.1.4.1.11.1.3.1.1.4      bindTimeLimit
      1.3.6.1.4.1.11.1.3.1.1.5      followReferrals
      1.3.6.1.4.1.11.1.3.1.1.6      authenticationMethod
      1.3.6.1.4.1.11.1.3.1.1.7      profileTTL
      1.3.6.1.4.1.11.1.3.1.1.9      attributeMap
      1.3.6.1.4.1.11.1.3.1.1.10     credentialLevel
      1.3.6.1.4.1.11.1.3.1.1.11     objectclassMap
      1.3.6.1.4.1.11.1.3.1.1.12     defaultSearchScope
      1.3.6.1.4.1.11.1.3.1.1.13     serviceCredentialLevel
      1.3.6.1.4.1.11.1.3.1.1.14     serviceSearchDescriptor
      1.3.6.1.4.1.11.1.3.1.1.15     serviceAuthenticationMethod
      1.3.6.1.4.1.11.1.3.1.1.16     dereferenceAliases
    Please also see the associated registration request for the
    DUAConfigProfile object class.

Neal-Joslin, et al. Informational [Page 32] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

9. References

9.1. Normative References

 [RFC2119]   Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, March 1997.
 [RFC3986]   Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
             Resource Identifier (URI): Generic Syntax", STD 66,
             RFC 3986, January 2005.
 [RFC4234]   Crocker, D., Ed. and P. Overell, "Augmented BNF for
             Syntax Specifications: ABNF", RFC 4234, October 2005.
 [RFC4510]   Zeilenga, K., "Lightweight Directory Access Protocol
             (LDAP): Technical Specification Road Map", RFC 4510,
             June 2006.
 [RFC4511]   Sermersheim, J., "Lightweight Directory Access Protocol
             (LDAP): The Protocol", RFC 4511, June 2006.
 [RFC4512]   Zeilenga, K., "Lightweight Directory Access Protocol
             (LDAP): Directory Information Models", RFC 4512,
             June 2006.
 [RFC4514]   Zeilenga, K., "Lightweight Directory Access Protocol
             (LDAP): String Representation of Distinguished Names",
             RFC 4514, June 2006.
 [RFC4516]   Smith, M. and T. Howes, "Lightweight Directory Access
             Protocol (LDAP): Uniform Resource Locator", RFC 4516,
             June 2006.
 [RFC4517]   Legg, S., "Lightweight Directory Access Protocol (LDAP):
             Syntaxes and Matching Rules", RFC 4517, June 2006.
 [RFC4519]   Sciberras, A., "Lightweight Directory Access Protocol
             (LDAP): Schema for User Applications", RFC 4519,
             June 2006.
 [SASLMECH]  IANA, "SIMPLE AUTHENTICATION AND SECURITY LAYER (SASL)
             MECHANISMS", July 2006,
             <http://www.iana.org/assignments/sasl-mechanisms>.

Neal-Joslin, et al. Informational [Page 33] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

9.2. Informative References

 [MSSFU]     Microsoft Corporation, "Windows Services for Unix 3.5",
             <http://www.microsoft.com/windows/sfu/>.
 [RFC2307]   Howard, L., "An Approach for Using LDAP as a Network
             Information Service", RFC 2307, March 1998.
 [RFC2789]   Freed, N. and S. Kille, "Mail Monitoring MIB", RFC 2789,
             March 2000.
 [RFC2831]   Leach, P. and C. Newman, "Using Digest Authentication as
             a SASL Mechanism", RFC 2831, May 2000.
 [RFC2849]   Good, G., "The LDAP Data Interchange Format (LDIF) -
             Technical Specification", RFC 2849, June 2000.
 [RFC4422]   Melnikov, A. and K. Zeilenga, "Simple Authentication and
             Security Layer (SASL)", RFC 4422, June 2006.
 [RFC4515]   Smith, M. and T. Howes, "Lightweight Directory Access
             Protocol (LDAP): String Representation of Search
             Filters", RFC 4515, June 2006.
 [RFC4520]   Zeilenga, K., "Internet Assigned Numbers Authority (IANA)
             Considerations for the Lightweight Directory Access
             Protocol (LDAP)", BCP 64, RFC 4520, June 2006.

Neal-Joslin, et al. Informational [Page 34] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

Appendix A. Examples

 In this section, we will describe a fictional DUA that provides one
 service, called the "email" service.  This service would be similar
 to an email client that uses an LDAP directory to discover email
 addresses based on a textual representation of the recipient's
 colloquial name.
 This email service is defined by default to expect that users with
 email addresses will be of the "inetOrgPerson" object class type
 [RFC2789].  And by default, the "email" service expects the
 colloquial name to be stored in the "cn" attribute, while it expects
 the email address to be stored in the "mail" attribute (as one would
 expect as defined by the inetOrgPerson object class).
 As a special feature, the "email" service will perform a special type
 of attribute mapping when performing searches.  If the "cn" attribute
 has been mapped to two or more attributes, the "email" service will
 parse the requested search string and map each whitespace-separated
 token into the mapped attributes, respectively.
 The default search filter for the "email" service is
 "(objectclass=inetOrgPerson)".  The email service also defines that
 when it performs a name-to-address discovery, it will wrap the search
 filter inside a complex search filter as follows:
 (&(<filter>)(cn~=<name string>))
 Or, if "cn" has been mapped to multiple attributes, that wrapping
 would appear as follows:
 (&(<filter>)(attr1~=<token1>)(attr2~=<token2>)...)
 The below examples show how the "email" service builds its search
 requests, based on the defined profile.  In all cases, the
 defaultSearchBase is "o=airius.com", and the defaultSearchScope is
 undefined.
 In addition, for all examples, we assume that the "email" service has
 been requested to discover the email address for "Jane Hernandez".
 Example 1:
 serviceSearchDescriptor: email:"ou=marketing,"
 base: ou=marketing,o=airius.com
 scope: sub
 filter: (&(objectclass=inetOrgPerson)(cn~=Jane Hernandez))

Neal-Joslin, et al. Informational [Page 35] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 Example 2:
 serviceSearchDescriptor: email:"ou=marketing,"?one?
  (&(objectclass=inetOrgPerson)(c=us))
 attributeMap: email:cn=2.5.4.42 sn
 Note: 2.5.4.42 is the OID that represents the "givenName"
 attribute.
 In this example, the email service performs <name string> parsing as
 described above to generate a complex search filter.  The above
 example results in one search.
 base: ou=marketing,o=airius.com
 scope: one
 filter: (&(&(objectclass=inetOrgPerson)(c=us))
             (2.5.4.42~=Jane)(sn~=Hernandez))
 Example 3:
 serviceSearchDescriptor: email:ou=marketing,"?base
 attributeMap: email:cn=name
 This example is invalid, because either the quote should have
 been escaped, or there should have been a leading quote.
 Example 4:
 serviceSearchDescriptor: email:ou=\\mar\\\\keting,\\"?base
 attributeMap: email:cn=name
 base: ou=\\mar\\keting,"
 scope: base
 filter (&(objectclass=inetOrgPerson)(name~=Jane Hernandez))
 Example 5:
 serviceSearchDescriptor: email:ou="marketing",o=supercom
 This example is invalid, since the quote was not a leading quote,
 and thus should have been escaped.

Neal-Joslin, et al. Informational [Page 36] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

 Example 6:
 serviceSearchDescriptor: email:??(&(objectclass=person)
                                  (ou=Org1 \\\\(temporary\\\\)))
 base: o=airius.com
 scope: sub
 filter: (&((&(objectclass=person)(ou=Org1 \\(Temporary\\)))
           (cn~=Jane Henderson)))
 Example 7:
 serviceSearchDescriptor: email:"ou=funny?org,"
 base: ou=funny?org,o=airius.com
 scope: sub
 filter (&(objectclass=inetOrgPerson)(cn~=Jane Hernandez))

Neal-Joslin, et al. Informational [Page 37] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

Authors' Addresses

 Bob Neal-Joslin (editor)
 Hewlett-Packard Company
 19420 Homestead RD
 M/S 4029
 Cupertino, CA  95014
 US
 Phone: +1 408 447 3044
 EMail: bob_joslin@hp.com
 URI:   http://www.hp.com
 Luke Howard
 PADL Software Pty. Ltd.
 PO Box 59
 Central Park, Vic  3145
 AU
 EMail: lukeh@padl.com
 URI:   http://www.padl.com
 Morteza Ansari
 Infoblox
 475 Potrero Avenue
 Sunnyvale, CA  94085
 US
 Phone: +1 408 716 4300
 EMail: morteza@infoblox.com

Neal-Joslin, et al. Informational [Page 38] RFC 4876 LDAP-Based Agent Configuration Schema May 2007

Full Copyright Statement

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 This document is subject to the rights, licenses and restrictions
 contained in BCP 78, and except as set forth therein, the authors
 retain all their rights.
 This document and the information contained herein are provided on an
 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
 THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
 OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

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Acknowledgement

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Neal-Joslin, et al. Informational [Page 39]

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