INTERNET-DRAFT Eric A. Hall Document: draft-ietf-crisp-lw-ipv4-00.txt July 2002 Expires: January, 2003 Defining and Locating IPv4 Address Blocks using the Internet Resource Query Service Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC 2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. 1. Abstract This document defines LDAP schema and searching rules for IPv4 addresses and address blocks, in support of the Internet Resource Query Service described in [ldap-whois]. Internet Draft draft-ietf-crisp-lw-ipv4-00.txt July 2002 2. Definitions and Terminology This document unites, enhances and clarifies several pre-existing technologies. Readers are expected to be familiar with the following specifications: RFC 2247 - Using Domains in LDAP/X.500 DNs RFC 2251 - Lightweight Directory Access Protocol (v3) RFC 2252 - Lightweight Directory Access Protocol (v3): Attribute Syntax Definitions. RFC 2254 - The String Representation of LDAP Search Filters [ir-dir-req] - <draft-newton-ir-dir-requirements-00.txt> - Internet Registry Directory Requirements [ldap-whois] - <draft-ietf-crisp-lw-core-00.txt> - The Internet Resource Query Service and the Internet Resource Schema The following abbreviations are used throughout this document: DIT (Directory Information Tree) - A DIT is a contained branch of the LDAP namespace, having a root of a particular distinguished name. "dc=example,dc=com" is used throughout this document as one DIT, with many example entries being stored in this DIT. DN (Distinguished Name) - A distinguished name provides a unique identifier for an entry, through the use of a multi- level naming syntax. Entries are named according to their location relevant to the root of their containing DIT. For example, "cn=inetResources,dc=example,dc=com" is a DN which uniquely identifies the "inetResources" entry within the "dc=example,dc=com" DIT. RDN (Relative DN) - An RDN provides a locally-scoped unique identifier for an entry. A complete, globally-unique DN is formed by concatenating the RDNs of an entry together. For example, "cn=admins,cn=inetResources,dc=example,dc=com" consists of two RDNs ("cn=admins" and "cn=inetResources") within the "dc=example,dc=com" DIT. RDNs are typically only referenced within their local scope. Hall & Newton I-D Expires: August 2002 [page 2]
Internet Draft draft-ietf-crisp-lw-ipv4-00.txt July 2002 OID (Object Identifier) - An OID is a globally-unique, concatenated set of integers which provide a kind of "serial number" to attributes, object classes, syntaxes and other schema elements. 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. 3. The inetIpv4Network Object Class The inetIpv4Network object class is a structural object class which provides administrative information about a specific IPv4 address and an associated subnet prefix (this pairing is most often used to represent the starting address of an IPv4 network, but can also be used to identify a specific host). 3.1. Naming syntax The naming syntax for IPv4 network entries MUST follow the form of "cn=<inetIpv4NetworkSyntax>,cn=inetResources,<dc-DIT>". Each IPv4 network address which is managed as a discrete LDAP-WHOIS network resource MUST have a dedicated entry in each of the DITs which provide public LDAP-WHOIS data regarding that network address. The inetIpv4NetworkSyntax component of an entry is subject to DN rules, although the inetIpv4NetworkSyntax is also used for extended search operations, and is therefore subject to specific syntax rules. The inetIpv4NetworkSyntax specifically requires the use of the starting address from a range of inclusive addresses, and specifically requires the use of CIDR prefix annotation. In this manner, it is possible to create an inetIpv4Network entry for a range of addresses (by specifying the starting address and the network prefix size), or a single host (by specifying the host- specific address and a /32 prefix). In this definition, inetIpv4NetworkSyntax uses the traditional "dotted-quad" notation, where each of four sub-components provide a decimal value that represents one octet from a 32-bit IPv4 address, with the sub-components being separated by a full-stop (period) character, and with the four-part sequence being followed by a "/" character and a three-digit decimal "prefix" value. An augmented BNF for this syntax is as follows: Hall & Newton I-D Expires: August 2002 [page 3]
Internet Draft draft-ietf-crisp-lw-ipv4-00.txt July 2002 inetIpv4NetworkSyntax = vFourPart "." vFourPart "." vFourPart "." vFourPart "/" vFourPrefix vFourPart = decimal value between "0" and "255" inclusive, with the non-affective leading zeroes removed vFourPrefix = decimal value between "1" and "32" inclusive, with the non-affective leading zeroes removed For example, an IPv4 network with a range of addresses between "10.0.0.0" and "10.0.255.255" inclusive would be written as "10.0.0.0/16", and would appear with an RDN of "cn=10.0.0.0/16". Similarly, a host address of "192.0.2.14" would have the RDN of "cn=192.0.2.14/32". The leading zeroes from each octet MUST be removed during query string formation. Octets which have a value of zero MUST be represented by the single-digit numeric value of "0". Note that the use of "/" is illegal in LDAP URLs when it is provided as data (in particular, URLs use this character as a part delimiter). This character MUST be escaped as "%2F" when it is provided as part of an inetIpv4Network entry in a ref attribute. 3.2. Schema definition IPv4 network entries MUST exist with the top, inetResources and inetIpv4Network object classes defined. If an entry exists as a referral, the entry MUST also be defined with the referral object class, in addition to the above requirements. The inetIpv4Network object class is a structural object class which is subordinate to the inetResources object class, and which MUST be treated as a container class capable of holding additional subordinate entries. The inetIpv4Network object class has no mandatory attributes, although it does have several optional attributes. The inetIpv4Network object class defines attributes which are specific to IPv4 networks, such as the delegation date and the status of the delegation. The inetIpv4Network object class is subordinate to the inetResources object class, so it inherits those attributes as well. Hall & Newton I-D Expires: August 2002 [page 4]
Internet Draft draft-ietf-crisp-lw-ipv4-00.txt July 2002 Some of the inetIpv4Network object class attributes define contact-related referrals which provide LDAP URLs that refer to inetOrgPerson entries, and these entries will need to be queried separately if detailed information about a particular contact is required. The contact attribute values follow the same rules as the labeledURI attribute defined in RFC 2079, with additional restrictions described in [ldap-whois]. The various ModifiedBy and ModifiedDate attributes SHOULD be treated as operational attributes. Their values SHOULD be filled in automatically by the database management application, and SHOULD NOT be returned except when explicitly requested. The schema definition for the inetIpv4Network object class is as follows: inetIpv4Network ( 1.3.6.1.4.1.7161.1.2.0 NAME 'inetIpv4Network' DESC 'IPv4 network attributes.' SUP inetResources STRUCTURAL MAY ( inetIpv4DelegationStatus $ inetIpv4DelegationDate $ inetIpv4DelegationModifiedDate $ inetIpv4DelegationModifiedBy $ inetIpv4Contacts $ inetIpv4ContactsModifiedBy $ inetIpv4ContactsModifiedDate $ inetIpv4RoutingContacts $ inetIpv4RoutingContactsModifiedBy $ inetIpv4RoutingContactsModifiedDate ) ) The attributes from the inetIpv4Network object class are described below: inetIpv4Contacts ( 1.3.6.1.4.1.7161.1.2.2 NAME 'inetIpv4Contacts' DESC 'Contacts for reporting problems with this IPv4 network.' EQUALITY caseExactMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 ) inetIpv4ContactsModifiedBy ( 1.3.6.1.4.1.7161.1.2.3 NAME 'inetIpv4ContactsModifiedBy' DESC 'Person who last modified the inetIpv4Contacts attribute.' EQUALITY distinguishedNameMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 SINGLE-VALUE USAGE distributedOperation ) Hall & Newton I-D Expires: August 2002 [page 5]
Internet Draft draft-ietf-crisp-lw-ipv4-00.txt July 2002 inetIpv4ContactsModifiedDate ( 1.3.6.1.4.1.7161.1.2.4 NAME 'inetIpv4ContactsModifiedDate' DESC 'Last modification date of the inetIpv4Contacts attribute.' EQUALITY generalizedTimeMatch ORDERING generalizedTimeOrderingMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.24 SINGLE-VALUE USAGE distributedOperation ) inetIpv4DelegationDate ( 1.3.6.1.4.1.7161.1.2.5 NAME 'inetIpv4DelegationDate' DESC 'Date of original delegation.' EQUALITY generalizedTimeMatch ORDERING generalizedTimeOrderingMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.24 SINGLE-VALUE ) inetIpv4DelegationModifiedBy ( 1.3.6.1.4.1.7161.1.2.6 NAME 'inetIpv4DelegationModifiedBy' DESC 'Person who last modified the inetIpv4DelegationStatus attribute.' EQUALITY distinguishedNameMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 SINGLE-VALUE USAGE distributedOperation ) inetIpv4DelegationModifiedDate ( 1.3.6.1.4.1.7161.1.2.7 NAME 'inetIpv4DelegationModifiedDate' DESC 'Last modification date of the inetIpv4DelegationStatus attribute.' EQUALITY generalizedTimeMatch ORDERING generalizedTimeOrderingMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.24 SINGLE-VALUE USAGE distributedOperation ) inetIpv4DelegationStatus ( 1.3.6.1.4.1.7161.1.2.8 NAME 'inetIpv4DelegationStatus' DESC 'Current delegation status code for this network.' EQUALITY numericStringMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.27{2} SINGLE-VALUE ) NOTE: In an effort to facilitate internationalization and programmatic processing, the current status of a delegation is identified by a 16-bit integer. The values and status mapping is as follows: 0 Reserved delegation (permanently inactive) 1 Assigned and active (normal state) 2 Assigned but not yet active (new delegation) 3 Assigned but on hold (disputed) 4 Assignment revoked (database purge pending) Hall & Newton I-D Expires: August 2002 [page 6]
Internet Draft draft-ietf-crisp-lw-ipv4-00.txt July 2002 Additional values for the inetIpv4DelegationStatus attribute are reserved for future use, and are to be administered by IANA. Note that there is no status code for "unassigned"; unassigned entries SHOULD NOT exist, and SHOULD NOT be returned as answers. inetIpv4RoutingContacts ( 1.3.6.1.4.1.7161.1.2.9 NAME 'inetIpv4RoutingContacts' DESC 'Contacts for routing issues with this IPv4 network.' EQUALITY caseExactMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 ) inetIpv4RoutingContactsModifiedBy ( 1.3.6.1.4.1.7161.1.2.10 NAME 'inetIpv4RoutingContactsModifiedBy' DESC 'Person who last modified the inetIpv4RoutingContacts attribute.' EQUALITY distinguishedNameMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 SINGLE-VALUE USAGE distributedOperation ) inetIpv4RoutingContactsModifiedDate ( 1.3.6.1.4.1.7161.1.2.11 NAME 'inetIpv4RoutingContactsModifiedDate' DESC 'Last modification date of the inetIpv4RoutingContacts attribute.' EQUALITY generalizedTimeMatch ORDERING generalizedTimeOrderingMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.24 SINGLE-VALUE USAGE distributedOperation ) The inetIpv4NetworkSyntax syntax is as follows: inetIpv4NetworkSyntax ( 1.3.6.1.4.1.7161.1.2.1 NAME 'inetIpv4NetworkSyntax' DESC 'An IPv4 address and prefix.' ) 3.3. Example An example of the inetIpv4Network object class is shown in Figure 1 below, with attributes from the inetResources object class also being used to provide administrative contacts. This data is a result of a query which was sent to the LDAP servers responsible for operating the "192.0.2.0/24" network block. Hall & Newton I-D Expires: August 2002 [page 7]
Internet Draft draft-ietf-crisp-lw-ipv4-00.txt July 2002 cn=192.0.2.0/24,cn=inetResources,dc=example,dc=com [top object class] [inetResources object class] [inetIpv4Network object class] | +-attribute: description | value: "The example.com network" | +-attribute: inetIpv4Contacts | value: "ldap://ldap.example.com/cn=hostmaster,ou=admins, | dc=example,dc=com" | +-attribute: inetGeneralContacts value: "ldap://ldap.example.com/cn=admins,ou=admins, dc=example,dc=com" Figure 1: The 192.0.2.0/24 inetIpv4Network entry. As stated earlier, reverse-lookup DNS domains for IPv4 address blocks are managed as inetDnsDomain object class entries. These are entirely different network resources, and should not be confused with inetIpv4Network object class entries. 4. The inetIpv4NetworkMatch Filter The inetIpv4NetworkMatch filter provides an identifier and search string format which collectively inform a queried server that a specific IPv4 address should be searched for, and that any matching inetIpv4network object class entries should be returned. NOTE: IPv4 addresses are also stored in DNS for reverse- lookups, and those entries are treated as inetDnsDomain object class entries rather than being treated as inetIpv4Network object class entries (they are treated as DNS zones with their own operational administrators). As such, those entries use the inetDnsDomainMatch query described in [ldap-whois-dns]. The inetIpv4NetworkMatch extensibleMatch filter is defined as follows: inetIpv4NetworkMatch ( 1.3.6.1.4.1.7161.1.2.12 NAME 'inetIpv4NetworkMatch' SYNTAX inetIpv4NetworkSyntax ) Hall & Newton I-D Expires: August 2002 [page 8]
Internet Draft draft-ietf-crisp-lw-ipv4-00.txt July 2002 The assertion value MUST be an IPv4 address, using the inetIpv4NetworkSyntax defined in section 3. Clients MUST provide assertion values in this syntax. If an input string does not match this syntax, the client MAY attempt to manipulate the input string such that an appropriate assertion value can be formed. For example, if a user enters a traditional IPv4 address without specifying a prefix value, the client MAY append "/32" to the end of the input string to form a valid assertion value. Similarly, if a user provides an octal or hexadecimal value, the client MAY attempt to convert the input string to the traditional dotted-quad IPv4 address notation. The server MUST compare the assertion value against the RDN of all entries in the inetResources container which have an object class of inetIpv4Network. Any entry for an IPv4 network resource which is clearly superior to the IPv4 address provided in the input string MUST be returned to the client. Superiority in this case means exactly what it sounds like: the address range specified by the inetIpv4Network object class entry (as determined by the network number and the prefix combination of the entry's RDN) MUST define a range of IPv4 addresses which encompasses the IPv4 address specified in the query, and any such entry MUST be returned in the response message. Entries which do not encompass the queried address MUST NOT be returned. Entries which do not have an object class of inetIpv4Network MUST NOT be returned. For example, assume that the client is submitting a search for "192.0.2.14/32", with the search base of "dc=in-addr,dc=arpa". The queried server may only have an inetIpv4Network entry for "cn=192.0.0.0/8,cn=inetResources,dc=in-addr,dc=arpa", and as such that would be the only entry returned. However, the server could also have multiple entries which matched the queried IPv4 address, such as "cn=192.0.0.0/8,cn=inetResources,dc=in-addr,dc=arpa" and "cn=192.0.2.0/24,cn=inetResources,dc=in-addr,dc=arpa", both of which reflected specific delegations. Similarly, a query for this IPv4 address which was sent to the LDAP servers responsible for the operational network could result in "cn=192.0.2.8/29,dc=2,dc=0,dc=192,dc=in-addr,dc=arpa" and "cn=192.0.2.14/32,dc=8/29,dc=2,dc=0,dc=192,dc=in-addr,dc=arpa" entries being returned to the client (assuming the subnet allocation policy of the network reflected this usage, and that there was an explicit entry for the IPv4 address in question). Hall & Newton I-D Expires: August 2002 [page 9]
Internet Draft draft-ietf-crisp-lw-ipv4-00.txt July 2002 Using the notation format described in RFC 2254, the search filter expression for the inetDnsDomainMatch query above would be written as "(1.3.6.1.4.1.7161.1.2.12:=192.0.2.14/32)". Response entries MAY be fully-developed inetIpv4Network entries, or MAY be referrals generated from entries which have the inetIpv4Network and referral object classes defined. Any attribute values which are received MUST be displayed by the client. If a subordinate reference referral is received, the client MUST restart the query, using the provided data as the new search base. If any continuation reference referrals are received, the client SHOULD start new queries for each reference, and append the output of those queries to the original query's output. 5. Security Considerations This document describes an application of the LDAPv3 protocol, and as such it inherits the security considerations associated with LDAPv3, as described in section 7 of RFC 2251. 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 LDAP-WHOIS 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 LDAP- WHOIS 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. 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. Hall & Newton I-D Expires: August 2002 [page 10]
Internet Draft draft-ietf-crisp-lw-ipv4-00.txt July 2002 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. 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 LDAP-WHOIS service without having reason to believe the veracity of the information. Users should limit unknown or untrusted information to routine purposes. 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. 6. IANA Considerations This document defines an application of the LDAPv3 protocol rather than a new Internet application protocol. As such, there are no protocol-related IANA considerations. However, this document does 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, rather than being assigned from a particular enterprise branch. Finally, this document also describes several instances where public DNS and LDAP servers are queried. It is expected that IANA will establish and maintain these LDAP servers (and the necessary DNS SRV domain names and resource records) required for this service to operate. This includes providing SRV resource records in the generic TLDs and the root domain, and also includes administering the referenced LDAP servers. 7. Author's Addresses Eric A. Hall ehall@ehsco.com Hall & Newton I-D Expires: August 2002 [page 11]
Internet Draft draft-ietf-crisp-lw-ipv4-00.txt July 2002 8. References RFC 2247 - Using Domains in LDAP/X.500 DNs RFC 2251 - Lightweight Directory Access Protocol (v3) RFC 2252 - Lightweight Directory Access Protocol (v3): Attribute Syntax Definitions. RFC 2254 - The String Representation of LDAP Search Filters [ir-dir-req] - <draft-newton-ir-dir-requirements-00.txt> - Internet Registry Directory Requirements [ldap-whois] - <draft-ietf-crisp-lw-core-00.txt> - The Internet Resource Query Service and the Internet Resource Schema 9. Acknowledgments Portions of this work were funded by Network Solutions, Inc. Hall & Newton I-D Expires: August 2002 [page 12]
