INTERNET-DRAFT Eric A. Hall
Document: draft-ietf-crisp-firs-arch-00.txt May 2003
Expires: December, 2003
Category: Standards-Track
The Federated Internet Registry Service:
Architecture and Implementation Guide
Status of this Memo
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Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
This document describes the architectural framework for the
Federated Internet Registry Service (FIRS), a distributed service
for storing, locating and transferring information about Internet
resources using LDAPv3.
Internet Draft draft-ietf-crisp-firs-arch-00.txt May 2003
Table of Contents
1. Introduction..............................................2
1.1. Background.............................................3
1.2. Overview...............................................4
2. Prerequisites and Terminology.............................5
2.1. Reference Example......................................6
3. The FIRS Namespace........................................8
3.1. The domainComponent Hierarchy..........................8
3.2. The inetResources Container............................9
3.3. Resource-Specific Entries..............................9
3.4. Namespace Aliases.....................................10
4. FIRS Schema Definitions..................................11
4.1. Global Schema Definitions.............................11
4.2. Resource-Specific Schema Definitions..................12
5. Query Processing Behaviors...............................13
5.1. Query Pre-Processing..................................13
5.2. Bootstrap Processing..................................15
5.3. Query Processing......................................16
5.4. Query Post-Processing.................................16
5.4.1. Referrals.......................................17
5.4.2. Internationalization and localization...........18
6. Transition Issues........................................19
6.1. NIC Handles...........................................20
6.2. Change-Logs...........................................20
7. Security Considerations..................................20
8. IANA Considerations......................................23
9. Author's Address.........................................23
10. Normative References.....................................23
11. Informational References.................................26
12. Acknowledgments..........................................26
13. Changes from Previous Versions...........................26
14. Full Copyright Statement.................................28
1. Introduction
FIRS is intended to provide a distributed WHOIS-like information
service, using the LDAPv3 specifications [RFC3377] for the data-
formatting and query-transport functions.
More specifically, the principle objective behind FIRS is to offer
structured information about distributed Internet resources in a
model which reflects the federated delegations of those resources.
This specifically includes centralized delegations from authorized
governance bodies (such as DNS domains within the "com" zone), but
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also includes delegations from authorized bodies further down the
delegation path (such as leaf-node DNS domain names within the
"example.com" zone).
Furthermore, the FIRS service is intended to be used with a wide
variety of resources. The core set of specifications define rules
for handling the most-common resources (DNS domains, IP addresses,
contact information, and so forth), but other types of resources
may be grafted onto the architecture as needed. By extension, FIRS
should be capable of providing the necessary support structure for
any kind of information to be stored in a global mesh of FIRS-
centric LDAP directories, and for the FIRS-specific clients and
servers to be easily extended to accommodate that data.
Another critical objective can be described as predictability, in
that FIRS-specific data should be easily accessible to a wide
number of applications. For example, if a network manager wants to
retrieve information about a particular host or network, it should
be easy for the management application to be extended so that the
FIRS data can be fetched by that application, rather than always
requiring the use of a FIRS-specific application.
Finally, the collection of specifications which define the
Federated Internet Registry Service (FIRS) are intended to satisfy
the CRISP Working Group requirements, as specified in draft-ietf-
crisp-requirements-05, "Cross Registry Internet Service Protocol
(CRISP) Requirements" [CRISP-REQ].
In order to achieve these objectives, the FIRS specifications
collectively define an LDAP-specific application, including
application-specific namespaces, object classes, attributes,
syntaxes, queries, behavioral rules, and more.
1.1. Background
The original WHOIS service [RFC812] was provided as a front-end to
a centralized repository of ARPANET resources and users. Over
time, hundreds of WHOIS servers have been deployed across the
public Internet, with each server providing general information
about the particular network resources under the control of a
specific organization.
Unfortunately, neither [RFC812] nor any of its successors define a
strict set of data-typing or formatting requirements, and as a
result, each of the different implementations provide different
kinds of information in slightly different ways. Furthermore, each
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WHOIS server operates as a self-contained entity, with no
standardized mechanisms to infer knowledge of any other servers,
meaning that WHOIS servers cannot redirect clients to other
servers for additional information. Another concern is that the
WHOIS services which are being operated today offer no means of
client authentication, requiring that server operators essentially
publish all data with a single "world-readable" permission.
However, this single permission conflicts with the privacy and
security policies of specific jurisdictions.
There are many other secondary issues with the WHOIS service as it
exists in current form. However, the largest problems are a lack
of standardized data formats, a lack of widely-supported referral
mechanisms, and a lack of privacy and security controls, as
described in the preceding text.
FIRS attempts to address these issues by defining guidelines for
the operation of a distributed and highly-structured WHOIS-like
service, using LDAPv3 for the query/response transfer service, and
using LDAP schema for the search inputs, answer data, and
redirection mechanisms. In short, the intention of this approach
is to provide an extensible and scalable WHOIS-like service, by
leveraging the inherent capabilities of LDAPv3.
1.2. Overview
The FIRS collection of specifications cumulatively define a
structured and distributed information service, including an
extensible framework and resource-specific definitions. The
framework defined in this document is intended to accommodate a
variety of different resource-types and usages, while the other
specifications define the technical details for the service as a
whole or for the different resource-types.
Cumulatively, the FIRS collection of specifications define the
following service elements:
* Namespace Rules. The FIRS specifications define a layered
namespace consisting of DNS-based delegation hierarchies, a
FIRS-specific container entry, and resource-specific
subordinate entries.
* Schema Definitions. The FIRS specifications reuse some
existing LDAP schema definitions, and also define several
FIRS-specific definitions, as needed.
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* The FIRS specifications also reuse some existing processing
rules, and define several additional rules as needed. Among
these rules are requirements for normalizing data, locating
servers, processing referrals, and more.
Some of these rules apply to the architecture as a whole, while
other rules apply to specific kinds of Internet resources.
2. Prerequisites and Terminology
The complete set of specifications in the FIRS collection
cumulative define a structured and distributed information service
using LDAPv3 for the data-formatting and transport functions. This
specification should be read in the context of the complete set of
specifications, which currently include the following:
draft-ietf-crisp-firs-arch-00, "The Federated Internet
Registry Service: Architecture and Implementation" (this
document) [FIRS-ARCH]
draft-ietf-crisp-firs-core-00, "The Federated Internet
Registry Service: Core Elements" [FIRS-CORE]
draft-ietf-crisp-firs-dns-00, "Defining and Locating DNS
Domains in the Federated Internet Registry Service"
[FIRS-DNS]
draft-ietf-crisp-firs-dnsrr-00, "Defining and Locating DNS
Resource Records in the Federated Internet Registry
Service" [FIRS-DNSRR]
draft-ietf-crisp-firs-contact-00, "Defining and Locating
Contact Persons in the Federated Internet Registry Service"
[FIRS-CONTCT]
draft-ietf-crisp-firs-asn-00, "Defining and Locating
Autonomous System Numbers in the Federated Internet
Registry Service" [FIRS-ASN]
draft-ietf-crisp-firs-ipv4-00, "Defining and Locating IPv4
Address Blocks in the Federated Internet Registry Service"
[FIRS-IPV4]
draft-ietf-crisp-firs-ipv6-00, "Defining and Locating IPv6
Address Blocks in the Federated Internet Registry Service"
[FIRS-IPV6]
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The FIRS service reuses, unites and clarifies several pre-existing
technologies. In order to fully understand FIRS, readers should be
familiar with the following technologies and specifications:
RFC 2247, "Using Domains in LDAP/X.500 DNs" [RFC2247]
RFC 2251, "Lightweight Directory Access Protocol (v3)"
[RFC2251]
RFC 2252, "Lightweight Directory Access Protocol (v3):
Attribute Syntax Definitions" [RFC2252]
RFC 2254, "The String Representation of LDAP Search
Filters" [RFC2254]
RFC 2256, "A Summary of the X.500(96) User Schema for use
with LDAPv3" [RFC2256]
RFC 2798, "Definition of the inetOrgPerson LDAP Object
Class" [RFC2798]
RFC 3296, "Named Subordinate References in Lightweight
Directory Access Protocol (LDAP) Directories" [RFC3296]
RFC 3377, "Lightweight Directory Access Protocol (v3):
Technical Specification" [RFC3377]
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 RFC 2119.
2.1. Reference Example
Figure 1 below shows an example of a FIRS-specific data-set. This
example is referenced throughout this specification.
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dc=example,dc=com
|
+-cn=inetResources,dc=example,dc=com
[top object class]
[inetResources object class]
|
+-attribute: inetGeneralContacts
| value: "admins@example.com"
|
+-cn=admins@example.com,cn=inetResources,dc=example,dc=com
| [top object class]
| [inetResources object class]
| [inetOrgPerson object class]
| |
| +-attribute: mail
| value: "admins@example.com"
|
+-cn=example.com,cn=inetResources,dc=example,dc=com
| [top object class]
| [inetResources object class]
| [inetDnsDomain object class]
| |
| +-attribute: inetDnsAuthServers
| value: "ns1.example.net"
|
+-cn=www.example.com,cn=inetResources,dc=example,dc=com
[top object class]
[inetResources object class]
[inetDnsDomain object class]
[referral object class]
|
+-attribute: inetTechContacts
| value: "admins@example.com"
|
+-attribute: ref
value: "ldap://firs.example.net/cn=inetResources,
dc=example,dc=net"???
(1.3.6.1.4.1.7161.1.1.8:=host.example.net)"
Figure 1: The FIRS-specific data for Example Widgets.
As can be seen in Figure 1, the entries use a FIRS-specific
namespace in conjunction with FIRS-specific schema, which clients
can use to generate FIRS-specific queries.
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3. The FIRS Namespace
A critical aspect of FIRS is the use of an application-specific
namespace which is imposed on all FIRS-based resources.
The FIRS namespace rules facilitate the programmatic creation of
lookups and searches, and ensure predictable results. The use of a
private namespace also help to segregate FIRS-related data from
other kinds of data which may reside on any participating server.
The FIRS namespace consists of three "layers", which are:
* A set of domainComponent relative distinguished names which
cumulatively identify a specific partition of the global
directory tree.
* A FIRS-specific entry which acts as a container for all of
the FIRS-related resource-specific child entries.
* The resource-specific child entries which collectively
contain detailed information about the resources under the
control of the selected partition.
The namespace follows a right-to-left order.
As an example, Figure 1 shows an DNS domain resource entry named
"cn=example.com,cn=inetResources,dc=example,dc=com", which refers
to the "example.com" domain resource within the "cn=inetResources"
container under the "dc=example,dc=com" directory partition.
3.1. The domainComponent Hierarchy
The top-level of the namespace uses the domainComponent naming and
mapping rules specified in RFC 2247 [RFC2247], which maps DNS
domain names to domainComponent ("dc=") relative distinguished
names (RDNs). The full sequence of domainComponent RDNs map to an
equivalent scope of authority in the DNS namespace, and
cumulatively represent the root of a partition of the global LDAP
directory space. For example, Figure 1 shows the directory
partition of "dc=example,dc=com" which maps to the "example.com"
scope of authority from the DNS hierarchy.
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3.2. The inetResources Container
This specification requires the use of a mandatory LDAP container
entry with the RDN of "cn=inetResources", which MUST exist at the
root of every directory database that provides FIRS services. All
publically-accessible resource-specific entries MUST be stored in
the cn=inetResources container entry.
The primary motivation for this naming rule is for predictability,
in that it allows searches to be formed programmatically (a search
base for resources in "dc=example,dc=com" can be programmatically
formed as "cn=inetResources,dc=example,dc=com", for example).
Furthermore, the use of a single container entry for all of an
organization's Internet resources allows that branch of the
directory database to be managed independently of other entries on
the server, which facilitates better operational security, and
also allows for the outsourcing of a FIRS container through the
use a single referral.
All told, the use of the inetResources container is important
enough to justify the MANDATORY usage of this naming syntax.
3.3. Resource-Specific Entries
The FIRS collection of specifications define several Internet
resource types, each of which have their own naming rules.
However, each resource type follows a consistent naming principle,
in that each specific resource has an RDN which uniquely
identifies that resource within the inetResources container entry.
For example, Figure 1 shows an entry for the "www.example.com"
domain name resource stored in the "dc=example,dc=com" directory
context, with a fully-qualified distinguished name (FQDN) of
"cn=www.example.com,cn=inetResources,dc=example,dc=com", and also
shows an entry for the "admins@example.com" contact resource with
the FQDN "admins@example.com,cn=inetResources,dc=example,dc=com".
Although the relative naming syntax is different for each resource
type, the syntax is consistent and predictable.
The naming rules for each of the distinct resource type are
provided in the documents which govern those resource types.
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3.4. Namespace Aliases
FIRS allows entries to alias for other entries through the use of
referrals. In this model, an entry exists which will match against
searches for the queried data, but the attributes associated with
that entry indicate that some other entry should also be queried.
Referrals represent one of the strongest capabilities of the FIRS
architecture, in that they allow for a significant variety of
cross-referencing among entries. For example, referrals can be
used to point an inetResources container entry in one partition to
another inetResources container entry in another partition,
allowing multiple partitions to effectively share a single
partition (this is useful when organizations manage multiple
networks or domains, and wish to consolidate their management). As
another example, referrals can also be used to create placeholder
entries for specific resources (such as a web server) which only
exist as referrals for resources which are managed in other
partitions (such as a web-hosting server at an ISP), with both
entries providing information about that resource.
This latter example can be seen in Figure 1, which shows an entry
for "cn=www.example.com,cn=inetResources,dc=example,dc=com" which
provides a referral to the "cn=host.example.net" entry at
"cn=inetResources,dc=example,dc=net". Queries for the local entry
would be answered with the locally-available information and then
redirected to the referral target where additional information
could be retrieved.
FIRS supports two different kinds of referrals, which are
subordinate reference referrals and continuation reference
referrals. Subordinate reference referrals indicate that the
search base used in the query only exists as an alias to another
partition or entry, meaning that the entire query must be
restarted in order for any answer data to be retrieved. Meanwhile,
continuation reference referrals indicate that some answer data is
available, but that more information is available at some other
location, and that the client should start new queries in order to
retrieve all of the information.
Referrals are provided as URLs. FIRS specifically requires the use
of LDAP URLs in order to ensure predictable automated processing.
Refer to section 5.4.1 for a brief discussion on how these URLs
are processed by FIRS clients.
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4. FIRS Schema Definitions
Another critical aspect of FIRS is the use of well-known schema,
including object classes, attributes, syntaxes and matching
filters. Some of the schema definitions are for the global FIRS
service (and are usable by all entries, including resource-
specific entries), while others are specific to particular
resource-types. Where suitable pre-existing schema definitions are
available, they are reused to facilitate integration with other
LDAP applications.
4.1. Global Schema Definitions
There are three global schema definitions which can be used by any
of the entries within the FIRS database. These include:
* The "inetResources" master schema. All FIRS-related entries
(including the inetResources container entry and all of the
resource-specific subordinate entries) MUST use the
inetResources structural object class and schema
definitions defined in [FIRS-CORE]. The inetResources
object class defines a variety of optional general-purpose
attributes which are useful for describing an organization
or the resources under its control.
* Associated resources. All FIRS-related entries MAY use the
"inetAssociatedResources" auxiliary object class and schema
definitions defined in [FIRS-CORE]. This object class
provides cross-reference pointer attributes which allow an
entry to reference other entries which may be of interest
to the user.
* Referral pointers. All FIRS-related entries MAY use the
"referral" object class and schema definitions defined in
[RFC3296]. This object class allows an entry to exist as a
referral source, with queries for that resource being
redirected to the referral target. Refer to section 5.4.1
for a discussion on the different kinds of referral and
reference mechanisms offered by FIRS.
Figure 1 shows that all of the entries within and including the
"cn=inetResources" container entry have the inetResources object
class defined, and that the "cn=www.example.com" resource-specific
entry also has the referral object class defined. Each of the
resource-specific entries in that example also have their own
resource-specific object classes.
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4.2. Resource-Specific Schema Definitions
In addition to the global schema definitions, each of the
resource-specific entry in FIRS MUST use the resource-specific
schema definitions defined for use with that specific resource
type. These object classes are defined in the specifications which
govern the different resource-types. These include:
* DNS domains. Every domain name resource entry MUST use the
inetDnsDomain object class and schema definitions defined
in [FIRS-DNS]. These entries can refer to sub-domain
delegations, host-specific entries, reverse-lookup entries,
or any other domain name resource, as needed.
* DNS resource-records. Any domain name resource MAY use the
inetDnsRR object class and schema definitions defined in
[FIRS-DNSRR]. The inetDnsRR object class defines a single
optional attribute for storing multiple DNS resource
records as supplemental data to a domain name entry.
* IPv4 address blocks. Every IPv4 network block entry MUST
use the inetIpv4Network object class and schema definitions
defined in [FIRS-IPV4]. Entries can refer to entire network
blocks or single hosts, as needed.
* IPv6 address blocks. Every IPv6 network block entry MUST
use the inetIpv6Network object class and schema definitions
defined in [FIRS-IPV6]. Entries can refer to entire network
blocks or single hosts, as needed.
* Autonomous system numbers. Every autonomous system number
entry MUST use the inetAsNumber object class and schema
definitions defined in [FIRS-ASN].
* Contacts. Every contact entry MUST use the inetOrgPerson
object class defined in [RFC2798], as well as the schema
definitions defined in [FIRS-CONTCT].
As was discussed in section 4.1, each resource-specific entry MAY
exist as a referral source, or MAY have attributes which refer to
additional (related) entries.
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5. Query Processing Behaviors
Another critical aspect to FIRS is the query-processing behavior.
These rules govern the ways in which a client parses a query,
locates a server which is authoritative for the resource being
queried, generates LDAPv3 queries, and processes any resulting
referrals. More specifically:
* Query pre-processing. The first step is for the client to
prepare the query. Portions of this process require the
client to determine the type of resource being queried for,
and to determine the initial partition which should be used
for the query. Since this process is different for each
particular resource-type, the rules which govern this
behavior are defined in each of the resource-specific
specifications.
* Bootstrap processing. Once a partition has been determined,
the client must locate the LDAP servers which are
authoritative for the resource in question. [FIRS-CORE]
defines three different bootstrap models that clients can
use as part of this process, while each of the resource-
specific specifications define which of the models are to
be used for each particular resource-type.
* Query processing. Once a server has been located, the
client must submit the LDAP query which was formed during
the pre-preprocessing phase. [FIRS-CORE] defines certain
LDAPv3 query parameters which all FIRS clients MUST conform
with, while the resource-specific specifications may also
define additional parameters.
* Query post-processing. FIRS explicitly supports several
different types of LDAP referral and redirection
mechanisms, any of which may result in the client
application restarting the query or initiating a brand-new
query. These mechanisms and their behavioral rules are
defined in [FIRS-CORE].
Each of these phases are discussed in more detail below.
5.1. Query Pre-Processing
Client input is generally provided as a single well-formed unit of
data, such as a domain name ("example.com") or an email address
("admins@example.com"). Since this information is typically all
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that's provided, it must be used to subsequently build a fully-
formed LDAPv3 query, including the assertion value, the search
base, the matching filter, and so forth. All of these steps are
part of the pre-processing phase.
Although the exact sequence of steps will vary according to the
resource-type being queried, there are some commonalities between
each of them. Among these steps:
* Determine the resource type. Different kinds of resources
have different processing steps, validation mechanisms, and
so forth, each of which require that the resource-type be
appropriately identified. Clients MAY use any mechanisms
necessary to force this determination.
* Validate and normalize the data. In all cases, the input
data MUST be validated and normalized according to the
syntax rules defined in the specification which governs the
resource-type. As an example of this step, queries for
internationalized domain names must be normalized into a
UTF-8 form before any other steps can be taken, with the
domain name being validated as part of the normalization
process. Similarly, IPv6 addresses are required to conform
to specific syntax rules, and input address may need to be
expanded or compressed in order to comply these syntax
requirements.
* Determine the appropriate directory partition for the
query. Different kinds of resources have different default
choices. In most cases, the appropriate partition will be a
variation of the input query string, but this is not always
the case. For example, the default partition for an email
address will be the domain component of the email address
itself, while the default partition for an ASN is a
reserved (special-purpose) domain name. In some cases, the
selected partition may change as a result of errors or
referrals encountered during later phases of the process.
* Determine the search base for the query. In most cases, the
search base will refer to the inetResources container entry
within the partition which was determined in the prior
step, with these elements being combined into an FQDN. In
some cases, the search base may need to be changed as a
result of referrals encountered during later phases of the
process.
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* Determine the assertion value for the query. The assertion
value will usually be the normalized form of the input
query. In some cases, the assertion value may need to be
changed as a result of referrals encountered during later
phases of the process.
* Determine the matching filter. Each resource-type has its
own matching filter rules. In some cases, the matching
filter will be a simple equalityMatch comparison, while in
other cases the matching filter will be an extensibleMatch
which is peculiar to the resource-type in use.
Once all of the pre-processing steps have been successfully
completed, the client must attempt to locate an LDAPv3 server
which is authoritative for that resource. This process is
described in section 5.2 below.
5.2. Bootstrap Processing
The bootstrap process uses DNS queries for SRV resource records
associated with the selected directory partition. However, since
different kinds of resources are managed through different
delegation models, there are also different bootstrap models which
have to be used to perform this process.
FIRS supports three different bootstrap models, which are:
* Targeted. The "targeted" bootstrap model has the client
attempting to locate the LDAP servers associated with a
absolute domain name, such as a domain name which may be
returned as referrals or URLs. If no servers can be found,
the client exits the query.
* Top-down. The "top-down" bootstrap model has the client
attempting to locate the LDAP servers associated with a
top-level domain (such as trying to locate the LDAP servers
associated with the "com" domain for an original query of
"www.example.com"). If no servers can be found for the top-
level domain, the client exits the query.
* Bottom-up. The "bottom-up" bootstrap model has the client
attempting to locate the LDAP servers associated with the
leaf-node domain (such as trying to locate any LDAP servers
associated with the "www.example.com" domain specifically).
If no servers can be found for that domain name, the
directory partition is reset to its immediate parent and
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the DNS query is resubmitted with that new scope. This
process continues until no more domains can be trimmed.
Each of the models are appropriate to different usages. For
example, The targeted model is most useful with pointer data
gleaned through URLs and other fixed sources, where the data is
presumed to exist at a pre-determined location. Meanwhile, the
top-down model is best suited for searches about global resources
which are centrally managed and delegated (such as IP addresses
and DNS domains), and where centrally-managed delegation
information is critical. Finally, the bottom-up model is most
appropriate for those resources which are managed by the end-users
directly (such as contact information, DNS resource records, and
so forth), and which are not typically managed from a centralized
delegation authority.
Once the bootstrap process has resulted in an authoritative LDAP
server being located for the partition in question, the remainder
of the query process is consistent.
5.3. Query Processing
Once an LDAP server has been located, the LDAPv3 query is
submitted to that server.
Most of the values for the query will have been collected during
the pre-processing phase, although [FIRS-CORE] defines some rules
which govern all queries. For example, [FIRS-CORE] specifies a
maximum time limit of 60 seconds for all queries in order to
prevent runaway searches which match all entries.
[FIRS-CORE] also allows for authentication and access controls, in
that FIRS servers are allowed to limit the depth and breadth of
information that they provide to a specific client based on the
level of authenticated access.
Another consideration which can arise during this phase of the
process is protocol and schema versioning considerations. These
mechanisms are already existent in the LDAPv3 specifications, and
their usage is encouraged by [FIRS-CORE].
5.4. Query Post-Processing
Once a query has been submitted and processed, the server should
return answer data or some kind of referral, or possibly both. In
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general, FIRS clients are expected to display all of the answer
data and process all of the referrals, although there are specific
considerations which must be taken into account. In particular,
there are considerations for handling the different kinds of
referrals, and there are localizations issues for specific kinds
of attribute data.
5.4.1. Referrals
As was discussed in section 3.4, there are two kinds of referral
mechanisms which are used with FIRS, which are subordinate
reference referrals and continuation reference referrals. More
specifically:
* Subordinate reference referrals. Subordinate reference
referrals are returned when the search base specified in a
query exists as a referral to some other entry. This
condition means that the current search operation cannot
proceed, and that the search MUST be restarted. Any of the
FIRS-specific entries MAY be defined as subordinate
reference referrals, although they are typically only used
when the inetResources container entry in a partition is an
alias for an inetResources container entry in another
partition. Subordinate reference referrals and their schema
are defined in RFC 3296 [RFC3296] although there are
additional restrictions placed on their usage as described
in [FIRS-CORE].
* Continuation reference referrals. Continuation reference
referrals are returned when a search operation has been
successfully processed by the queried server, but the
answer data also includes referrals to other entries. These
referrals are often provided as supplemental data to an
answer set, although this is not required (a continuation
reference referral can be the only response, but it won't
be the only response in the common case). This condition
means that the current search operation has partially
succeeded, but that additional searches SHOULD be started
in order for all of the answer data to be. Continuation
reference referrals and their schema are also defined in
[RFC3296], with additional restrictions placed on their
usage as described in [FIRS-CORE].
Whenever a referral is received in response to a query, the client
MUST display any answer data which has been received and then
process the referral. As part of this process, the client MUST
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parse the URL for the host identifier, port number, search base,
and assertion value (if these are provided), and then construct
and issue new queries using these values.
Note that RFC 2251 [RFC2251] defines a superior reference referral
which is used as a "default referral" for out-of-scope searches.
However, FIRS specifically excludes support for superior reference
referrals. Any superior reference referrals which are encountered
as part of this service are to be treated as errors.
5.4.2. Internationalization and localization
The FIRS model uses the internationalization and localization
services provided by LDAPv3. In this regard, FIRS clients do not
need to implement any special services in order to process and
display internationalized attribute data if those attribute types
already provide direct support for internationalized data.
However, there are several instances where this is not the case.
The areas where specific considerations have been made to fully
accommodate internationalization and localization concerns are
described below.
* The domainComponent attribute is restricted to [US-ASCII].
This is problematic with internationalized domain names and
their use in directory information trees, search bases, and
so forth. In order to ensure interoperability, this
specification requires all DNS domain names which are
mapped to domainComponent attributes to be normalized and
reduced to their ASCII-compatible form using the "ToASCII"
process defined in [RFC3490] before these sequences are
stored in the directory or used in LDAPv3 messages.
* DNS is technically capable of storing eight-bit codepoint
values, although the operational rules which govern DNS do
not support this usage. As a result, internationalized
domain names which are used for SRV or A resource record
lookups MUST be normalized and reduced to their ASCII-
compatible form using the "ToASCII" process defined in
[RFC3490] before these queries are issued.
* Some URLs may need to be escaped in order to accommodate
internationalized strings (the rules and requirements for
this process are defined in the specifications which govern
each kind of URL).
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* RFC 2277 [RFC2277] requires that free-text data must be
accompanied with language tags. RFC 2596 [RFC2596] defines
a mechanism for storing language tags and language-specific
attribute values, and these mechanisms SHOULD be supported
by FIRS clients and servers. For example, an organization
name could be provided in English and Arabic, with the
language tags allowing the client application to view the
appropriate attribute value instance, if both the client
and the server support the mechanisms defined in RFC 2596.
Note that attribute values which contain structured data
(even if there is no structure in LDAP) do not necessarily
benefit from language tags. Examples of the latter include
the labeledURI and mail attributes, which do not typically
have multiple linguistic representations.
* Time and date strings usually use the generalizedTime
syntax, making them predictable. Dates MAY be localized for
display purposes by client applications as necessary.
* Attribute names are static and well-known, and are
therefore easily localized. As such, clients MAY choose to
convert attribute names in a language appropriate to the
local user for display purposes where it is safe to do so.
However, clients MUST NOT localize attribute names which
are used for query input. Specific examples of the latter
would be converting "cn=" or "dc=" relative distinguished
labels into some other language.
* International postal regulations generally require that the
recipient address be provided in a language and charset
which is native to the recipient's country, with the
exception of the destination country code which should be
provided in a language and charset that is native to the
sender's country (this allows the sender's post office to
route the mail to the recipient's country, while allowing
the destination country to perform local delivery). In
order to facilitate this usage, the country attribute value
MAY (encouraged) be localized to the local user's
nomenclature for a country, but other postal address
information SHOULD NOT be localized.
6. Transition Issues
There are a handful of areas where the proposed service does not
fully match with all of the existing WHOIS service offerings.
These areas are discussed in more detail below.
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6.1. NIC Handles
Legacy NIC handles in existing databases can be accommodated using
two possible mechanisms:
* NIC handle output in legacy WHOIS systems may be replaced
with email addresses for the contacts. This option
facilitates faster coalescence around the FIRS system.
* NIC handles can be converted into locally-scoped email
addresses. For example, the NIC handle of EH26 on Network
Solutions' WHOIS server could be replaced with the locally-
scoped email address of "ehall@whois.netsol.com" or some
variation thereof.
Of the two mechanisms described above, the former is preferred.
6.2. Change-Logs
Several WHOIS services provide pseudo change-logs in their
response data, listing each unique modification event which has
occurred for a particular resource. For example, RIPE and some of
its member ccTLDs provide WHOIS output which includes a series of
"changed" fields that itemize every modification event ("updated",
"added", etc.), the modifier, and the modification date, which
cumulatively act as a change-log for the resource in question.
Organizations are certainly free to maintain this information on
their internal systems (and are even encouraged to do so).
However, this information is not necessary for public view of the
data in the FIRS service. Where the auditing information will be
required, a format which is more suitable to legal review will
also be required.
Organizations who wish to publish change-log information should
develop a common schema for this purpose. An initial demonstration
schema has been developed by the author and is available at
http://www.ehsco.com/misc/draft-hall-ldap-audit-00.txt
7. Security Considerations
The FIRS collection of specifications describe an application of
the LDAPv3 protocol, and as such it inherits the security
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considerations associated with LDAPv3, as described in section 7
of [RFC2251].
By nature, LDAP is a read-write protocol, while the legacy WHOIS
service has always been a read-only service. As such, there are
significant risks associated with allowing unintended updates by
unauthorized third-parties. Moreover, allowing the FIRS service to
update the underlying delegation databases could result in network
resources being stolen from their lawful operators. For example,
if the LDAP front-end had update access to a domain delegation
database, a malicious third-party could theoretically take
ownership of that domain by exploiting an authentication weakness,
thereby causing ownership of the domain to be changed to another
party. For this reason, it is imperative that the FIRS service not
be allowed to make critical modifications to delegated resources
without ensuring that all possible precautions have been taken.
The query processing models described in this document make use of
DNS lookups in order to locate the LDAP servers associated with a
particular resource. DNS is susceptible to certain attacks and
forgeries which may be used to redirect clients to LDAP servers
which are not authoritative for the resource in question.
This document provides multiple query models which will cause the
same query to be answered by different servers (one would be
processed by a delegation entity, while another would be processed
by an operational entity). As a result, each of the servers may
provide different information, depending upon the query type that
was originally selected.
Some operators may choose to purposefully provide misleading or
erroneous information in an effort to avoid responsibility for bad
behavior. In addition, there are likely to be sporadic operator
errors which will result in confusing or erroneous answers.
Neither this specification nor the LDAPv3 protocol currently
provide cache timers or any other mechanisms which can indicate
how accurate or timely any replicas may be. As a result, it is
possible for a replica to become significantly outdated, even to
the point of containing wholesale errors.
For all of the reasons listed above, it is essential that
applications and end-users not make critical decisions based on
the information provided by the FIRS service without having reason
to believe the veracity of the information. Users should limit
unknown or untrusted information to routine purposes.
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Despite these disclaimers, however, it is very likely that the
information presented through the FIRS service will be used for
many operational and problem-resolution purposes. In order to
ensure the veracity of the information, a minimal set of
operational guidelines are provided herein. For the most part,
these rules are designed to prevent unauthorized modifications to
the data.
Note that these rules only apply to data which is willingly
provided; no data is required to be entered, but where the data is
provided, it SHOULD be validated as accurate on entry, and it MUST
be secured against unauthorized modifications.
* The inetResources container entry and all of the resource-
specific subordinate entries within every public DIT that
provides FIRS resources SHOULD have anonymous read-only
access permissions, and SHOULD NOT have anonymous add,
delete or modify permissions.
* With the exception of contact-related attributes from the
inetOrgPerson object class, each attribute MAY have
whatever restrictions are necessary in order to suit local
security policies, government regulations or personal
privacy concerns. When the inetOrgPerson object class is
used to provide contact details, the mail attribute MUST be
defined, SHOULD be valid, SHOULD have read-only anonymous
access, and SHOULD NOT have anonymous add, delete or modify
permissions.
By using the inetOrgPerson object class, it is expected
that existing contact-related entries can be reused. If
reusing these entries is undesirable or unfeasible, entries
with the necessary access SHOULD be made available.
Note that contact pointers are entirely optional and are
not required to exist. However, where they exist, they MUST
comply with the above requirements.
* End-users and implementers SHOULD provide anonymous access
to the creatorsName, createTimestamp, modifiersName and
modifyTimestamp operational attributes associated with each
entry in the inetResources branch, since this information
is useful for determining the age of the information.
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* Server administrators MAY define additional add, delete or
modify permissions for authenticated users, using any
LDAPv3 authentication mechanisms they wish. In particular,
delegation entities MAY provide for the remote management
of delegated resources (such as assigning modification
privileges to the managers of a particular delegated domain
or address block), although this is entirely optional, and
is within the sole discretion of the delegation body.
Finally, there are physical security issues associated with any
service which provides physical addressing and delivery
information. Although organizations are generally encouraged to
provide as much information as they feel comfortable with, no
information is required.
8. IANA Considerations
The FIRS collection of specifications define an application of the
LDAPv3 protocol rather than a new Internet application protocol.
As such, there are no protocol-related IANA considerations.
However, the FIRS collection of specifications do define several
LDAP schema elements, including object classes, attributes,
syntaxes and extensibleMatch filters, and these elements should be
assigned OID values from the IANA branch. Furthermore, some of the
specifications define their own status codes as attribute values,
and IANA is expected to maintain the code-point mapping values
associated with these attributes.
Finally, some of the specifications also describe public DNS and
LDAP data (including SRV resource records and LDAPv3 referrals).
It is expected that IANA will see to the establishment and
maintenance of these servers and data.
9. Author's Address
Eric A. Hall
ehall@ehsco.com
10. Normative References
[RFC1274] Barker, P., and Kille, S. "The COSINE and
Internet X.500 Schema", RFC 1274, November
1991.
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[RFC2079] Smith, M. "Definition of an X.500 Attribute
Type and an Object Class to Hold Uniform
Resource Identifiers (URIs)", RFC 2079,
January 1997.
[RFC2247] Kille, S., Wahl, M., Grimstad, A., Huber, R.,
and Sataluri, S. "Using Domains in LDAP/X.500
DNs", RFC 2247, January 1998.
[RFC2251] Wahl, M., Howes, T., and Kille, S.
"Lightweight Directory Access Protocol (v3)",
RFC 2251, December 1997.
[RFC2252] Wahl, M., Coulbeck, A., Howes, T., and Kille,
S. "Lightweight Directory Access Protocol
(v3): Attribute Syntax Definitions", RFC 2252,
December 1997.
[RFC2253] Wahl, M., Kille, S., and Howes, T.
"Lightweight Directory Access Protocol (v3):
UTF-8 String Representation of DNs", RFC 2253,
December 1997.
[RFC2254] Howes, T. "The String Representation of LDAP
Search Filters", RFC 2254, December 1997.
[RFC2255] Howes, T., and Smith, M. "The LDAP URL
Format", RFC 2255, December 1997.
[RFC2256] Wahl, M. "A Summary of the X.500(96) User
Schema for use with LDAPv3", RFC 2256,
December 1997.
[RFC2277] Alvestrand, H. "IETF Policy on Character Sets
and Languages", BCP 18, RFC 2277, January
1998.
[RFC2308] Andrews, M. "Negative Caching of DNS Queries
(DNS NCACHE)", RFC 2308, March 1998.
[RFC2596] Wahl, M., and Howes, T. "Use of Language Codes
in LDAP", RFC 2596, May 1999.
[RFC2782] Gulbrandsen, A., Vixie, P., and Esibov, L. "A
DNS RR for specifying the location of services
(DNS SRV)", RFC 2782, February 2000.
[RFC2798] Smith, M. "Definition of the inetOrgPerson
LDAP Object Class", RFC 2798, April 2000.
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[RFC3296] Zeilenga, K. "Named Subordinate References in
Lightweight Directory Access Protocol (LDAP)
Directories", RFC 3296, July 2002.
[RFC3377] Hodges, J., and Morgan, R. "Lightweight
Directory Access Protocol (v3): Technical
Specification", RFC 3377, September 2002.
[RFC3490] Faltstrom, P., Hoffman, P., and Costello, A.
"Internationalizing Domain Names in
Applications (IDNA)", RFC 3490, March 2003.
[CRISP-REQ] Newton, A. "Cross Registry Internet Service
Protocol (CRISP) Requirements", draft-ietf-
crisp-requirements-05, May 2003.
[FIRS-ARCH] Hall, E. "The Federated Internet Registry
Service: Architecture and Implementation
Guide", draft-ietf-crisp-firs-arch-00, May
2003.
[FIRS-ASN] Hall, E. "Defining and Locating Autonomous
System Numbers in the Federated Internet
Registry Service", draft-ietf-crisp-firs-asn-
00, May 2003.
[FIRS-CONTCT] Hall, E. "Defining and Locating Contact
Persons in the Federated Internet Registry
Service", draft-ietf-crisp-firs-contact-00,
May 2003.
[FIRS-CORE] Hall, E. "The Federated Internet Registry
Service: Core Elements", draft-ietf-crisp-
firs-core-00, May 2003.
[FIRS-DNS] Hall, E. "Defining and Locating DNS Domains in
the Federated Internet Registry Service",
draft-ietf-crisp-firs-dns-00, May 2003.
[FIRS-DNSRR] Hall, E. "Defining and Locating DNS Resource
Records in the Federated Internet Registry
Service", draft-ietf-crisp-firs-dnsrr-00, May
2003.
[FIRS-IPV4] Hall, E. "Defining and Locating IPv4 Address
Blocks in the Federated Internet Registry
Service", draft-ietf-crisp-firs-ipv4-00, May
2003.
[FIRS-IPV6] Hall, E. "Defining and Locating IPv6 Address
Blocks in the Federated Internet Registry
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Service", draft-ietf-crisp-firs-ipv6-00, May
2003.
[US-ASCII] Cerf, V. "ASCII format for Network
Interchange", RFC 20, October 1969.
11. Informational References
[RFC812] Harrenstien, K., and White, V.
"NICNAME/WHOIS", RFC 812, March 1982.
12. Acknowledgments
Funding for the RFC editor function is currently provided by the
Internet Society.
Portions of this document were funded by Verisign Labs.
The first version of this specification was co-authored by Andrew
Newton of Verisign Labs, and subsequent versions continue to be
developed with his active participation.
13. Changes from Previous Versions
draft-ietf-crisp-fir-arch-00:
* Restructured document set, separating the architectural
discussion from the technical descriptions.
* Consolidated the security discussions.
draft-ietf-crisp-lw-core-00:
* As a result of the formation of the CRISP working group,
the original monolithic document has been broken into
multiple documents, with draft-ietf-crisp-lw-core
describing the core service, while related documents
describe the per-resource schema and access mechanisms.
* References to the ldaps: URL scheme have been removed,
since there is no standards-track specification for the
ldaps: scheme.
* An acknowledgements section was added.
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draft-hall-FIRS-01:
* The ôObjectivesö section has been removed. [ir-dir-req] is
now being used as the guiding document for this service.
* Several typographical errors have been fixed.
* Some unnecessary text has been removed.
* Figures changed to show complete sets of object classes, to
improve inheritance visibility.
* Clarified the handling of reverse-lookup domains (zones
within the in-addr.arpa portion of the DNS hierarchy) in
the inetDnsDomain object class reference text.
* Referrals now use regular LDAP URLs (multiple responses
with explicit hostnames and port numbers). Prior editions
of this specification used LDAP SRV resource records for
all referrals.
* The delegation status codes used by the
inetDnsDelegationStatus, inetIpv4DelegationStatus,
inetIpv6DelegationStatus and inetAsnDelegationStatus
attributes have been condensed to a more logical set.
* Added an inetDnsAuthServers attribute for publishing the
authoritative DNS servers associated with a domain. NOTE
THAT THIS IS A TEMPORARY ATTRIBUTE THAT WILL EVENTUALLY BE
REPLACED BY GENERALIZED RESOURCE-RECORD ENTRIES AND
ATTRIBUTES.
* Added an inetGeneralDisclaimer attribute for publishing
generalized disclaimers.
* Added the inetAssociatedResources auxiliary object class
for defining associated resources, and moved some of the IP
addressing and ASN attributes to the new object class.
* Several attributes had their OIDs changed. NOTE THAT THIS
IS AN INTERNET DRAFT, AND THAT THE OIDS ARE SUBJECT TO
ADDITIONAL CHANGES AS THIS DOCUMENT IS EDITED.
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14. Full Copyright Statement
Copyright (C) The Internet Society (2003). All Rights Reserved.
This document and translations of it may be copied and furnished
to others, and derivative works that comment on or otherwise
explain it or assist in its implementation may be prepared,
copied, published and distributed, in whole or in part, without
restriction of any kind, provided that the above copyright notice
and this paragraph are included on all such copies and derivative
works. However, this document itself may not be modified in any
way, such as by removing the copyright notice or references to the
Internet Society or other Internet organizations, except as needed
for the purpose of developing Internet standards in which case the
procedures for copyrights defined in the Internet Standards
process must be followed, or as required to translate it into
languages other than English.
The limited permissions granted above are perpetual and will not
be revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on
an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
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