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.
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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
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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
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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].
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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.
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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.
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( 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 )
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( 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 )
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( 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.
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( 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
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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
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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].
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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]).
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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.
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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.
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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
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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))
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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.
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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))
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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
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RFC 4876 LDAP-Based Agent Configuration Schema May 2007
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