RFC 9092: Finding and Using Geofeed Data
- R. Bush,
- M. Candela,
- W. Kumari,
- R. Housley
This RFC is now obsolete
Abstract
This document specifies how to augment the Routing Policy Specification Language inetnum: class to refer specifically to geofeed data comma-separated values (CSV) files and describes an optional scheme that uses the Routing Public Key Infrastructure to authenticate the geofeed data CSV files.¶
Status of This Memo
This is an Internet Standards Track document.¶
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.¶
Information about the current status of this document, any
errata, and how to provide feedback on it may be obtained at
https://
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the document authors. All rights reserved.¶
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://
1. Introduction
Providers of Internet content and other services may wish to customize those services based on the geographic location of the user of the service. This is often done using the source IP address used to contact the service. Also, infrastructure and other services might wish to publish the locale of their services. [RFC8805] defines geofeed, a syntax to associate geographic locales with IP addresses, but it does not specify how to find the relevant geofeed data given an IP address.¶
This document specifies how to augment the Routing Policy Specification Language (RPSL) [RFC2725] inetnum: class to refer specifically to geofeed data CSV files and how to prudently use them. In all places inetnum: is used, inet6num: should also be assumed [RFC4012].¶
The reader may find [INETNUM] and [INET6NUM] informative, and certainly more verbose, descriptions of the inetnum: database classes.¶
An optional utterly awesome but slightly complex means for authenticating geofeed data is also defined.¶
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.¶
2. Geofeed Files
Geofeed files are described in [RFC8805]. They provide a facility for an IP address resource "owner" to associate those IP addresses to geographic locales.¶
Content providers and other parties who wish to locate an IP address to a geographic locale need to find the relevant geofeed data. In Section 3, this document specifies how to find the relevant geofeed [RFC8805] file given an IP address.¶
Geofeed data for large providers with significant horizontal scale and high granularity can be quite large. The size of a file can be even larger if an unsigned geofeed file combines data for many prefixes, if dual IPv4/IPv6 spaces are represented, etc.¶
Geofeed data do have privacy considerations (see Section 6); this process makes bulk access to those data easier.¶
This document also suggests an optional signature to strongly authenticate the data in the geofeed files.¶
3. inetnum: Class
The original RPSL specifications starting with [RIPE81], [RIPE181], and a trail of subsequent documents were written by the RIPE community. The IETF standardized RPSL in [RFC2622] and [RFC4012]. Since then, it has been modified and extensively enhanced in the Regional Internet Registry (RIR) community, mostly by RIPE [RIPE-DB]. Currently, change control effectively lies in the operator community.¶
The RPSL, and [RFC2725] and [RFC4012] used by the Regional Internet Registries (RIRs), specify the inetnum: database class. Each of these objects describes an IP address range and its attributes. The inetnum: objects form a hierarchy ordered on the address space.¶
Ideally, RPSL would be augmented to define a new RPSL geofeed: attribute in the inetnum: class. Until such time, this document defines the syntax of a Geofeed remarks: attribute, which contains an HTTPS URL of a geofeed file. The format of the inetnum: geofeed remarks: attribute MUST be as in this example, "remarks: Geofeed ", where the token "Geofeed " MUST be case sensitive, followed by a URL that will vary, but it MUST refer only to a single geofeed [RFC8805] file.¶
While we leave global agreement of RPSL modification to the relevant parties, we specify that a proper geofeed: attribute in the inetnum: class MUST be "geofeed:" and MUST be followed by a single URL that will vary, but it MUST refer only to a single geofeed [RFC8805] file.¶
Registries MAY, for the interim, provide a mix of the remarks: attribute form and the geofeed: attribute form.¶
The URL uses HTTPS, so the WebPKI provides authentication, integrity, and confidentiality for the fetched geofeed file. However, the WebPKI can not provide authentication of IP address space assignment. In contrast, the RPKI (see [RFC6481]) can be used to authenticate IP space assignment; see optional authentication in Section 4.¶
Until all producers of inetnum: objects, i.e., the RIRs, state that they have migrated to supporting a geofeed: attribute, consumers looking at inetnum: objects to find geofeed URLs MUST be able to consume both the remarks: and geofeed: forms. The migration not only implies that the RIRs support the geofeed: attribute, but that all registrants have migrated any inetnum: objects from remarks: to geofeed: attributes.¶
Any particular inetnum: object MUST have, at most, one geofeed reference, whether a remarks: or a proper geofeed: attribute when it is implemented. If there is more than one, all are ignored.¶
If a geofeed CSV file describes multiple disjoint ranges of IP address space, there are likely to be geofeed references from multiple inetnum: objects. Files with geofeed references from multiple inetnum: objects are not compatible with the signing procedure in Section 4.¶
When geofeed references are provided by multiple inetnum: objects that have identical address ranges, then the geofeed reference on the inetnum: with the most recent last-modified: attribute SHOULD be preferred.¶
As inetnum: objects form a hierarchy, geofeed references SHOULD be at the lowest applicable inetnum: object covering the relevant address ranges in the referenced geofeed file. When fetching, the most specific inetnum: object with a geofeed reference MUST be used.¶
It is significant that geofeed data may have finer granularity than the inetnum: that refers to them. For example, an INETNUM object for an address range P could refer to a geofeed file in which P has been subdivided into one or more longer prefixes.¶
Currently, the registry data published by ARIN are not the same RPSL as that of the other registries (see [RFC7485] for a survey of the WHOIS Tower of Babel); therefore, when fetching from ARIN via FTP [RFC0959], WHOIS [RFC3912], the Registration Data Access Protocol (RDAP) [RFC9082], etc., the "NetRange" attribute/key MUST be treated as "inetnum", and the "Comment" attribute MUST be treated as "remarks".¶
4. Authenticating Geofeed Data
The question arises whether a particular geofeed [RFC8805] data set is valid, i.e., is authorized by the "owner" of the IP address space and is authoritative in some sense. The inetnum: that points to the geofeed [RFC8805] file provides some assurance. Unfortunately, the RPSL in many repositories is weakly authenticated at best. An approach where RPSL was signed per [RFC7909] would be good, except it would have to be deployed by all RPSL registries, and there is a fair number of them.¶
A single optional authenticator MAY be appended to a geofeed [RFC8805] file. It is a digest of the main body of the file signed by the private key of the relevant RPKI certificate for a covering address range. One needs a format that bundles the relevant RPKI certificate with the signature of the geofeed text.¶
The canonicalizatio
Should the authenticator be syntactically incorrect per the above, the authenticator is invalid.¶
Borrowing detached signatures from [RFC5485], after file canonicalizatio
The address range of the signing certificate MUST cover all prefixes in the geofeed file it signs.¶
An address range A "covers" address range B if the range of B is identical to or a subset of A. "Address range" is used here because inetnum: objects and RPKI certificates need not align on Classless Inter-Domain Routing (CIDR) [RFC4632] prefix boundaries, while those of the CSV lines in a geofeed file do.¶
As the signer specifies the covered RPKI resources relevant to the signature, the RPKI certificate covering the inetnum: object's address range is included in the [RFC5652] CMS SignedData certificates field.¶
Identifying the private key associated with the certificate and getting the department that controls the private key (which might be trapped in a Hardware Security Module (HSM)) to sign the CMS blob is left as an exercise for the implementor. On the other hand, verifying the signature requires no complexity; the certificate, which can be validated in the public RPKI, has the needed public key. The trust anchors for the RIRs are expected to already be available to the party performing signature validation. Validation of the CMS signature on the geofeed file involves:¶
All of these steps MUST be successful to consider the geofeed file signature as valid.¶
As the signer specifies the covered RPKI resources relevant to the signature, the RPKI certificate covering the inetnum: object's address range is included in the CMS SignedData certificates field [RFC5652].¶
Identifying the private key associated with the certificate and getting the department with the Hardware Security Module (HSM) to sign the CMS blob is left as an exercise for the implementor. On the other hand, verifying the signature requires no complexity; the certificate, which can be validated in the public RPKI, has the needed public key.¶
The appendix MUST be hidden as a series of "#" comments at the
end of the geofeed file. The following is a cryptographical
The signature does not cover the signature lines.¶
The bracketing "# RPKI Signature:" and "# End Signature:" MUST be present following the model as shown. Their IP address range MUST match that of the inetnum: URL followed to the file.¶
[RPKI-RSC] describes and provides code for a CMS profile for a general purpose listing of checksums (a "checklist") for use with the Resource Public Key Infrastructure (RPKI). It provides usable, albeit complex, code to sign geofeed files.¶
[RPKI-RTA] describes a CMS profile for a general purpose Resource Tagged Attestation (RTA) based on the RPKI. While this is expected to become applicable in the long run, for the purposes of this document, a self-signed root trust anchor is used.¶
5. Operational Considerations
To create the needed inetnum: objects, an operator wishing to register the location of their geofeed file needs to coordinate with their Regional Internet Registry (RIR) or National Internet Registry (NIR) and/or any provider Local Internet Registry (LIR) that has assigned address ranges to them. RIRs/NIRs provide means for assignees to create and maintain inetnum: objects. They also provide means of assigning or sub-assigning IP address resources and allowing the assignee to create WHOIS data, including inetnum: objects, thereby referring to geofeed files.¶
The geofeed files MUST be published via and fetched using HTTPS [RFC2818].¶
When using data from a geofeed file, one MUST ignore data outside the referring inetnum: object's inetnum: attribute address range.¶
If and only if the geofeed file is not signed per Section 4, then multiple inetnum: objects MAY refer to the same geofeed file, and the consumer MUST use only lines in the geofeed file where the prefix is covered by the address range of the inetnum: object's URL it has followed.¶
If the geofeed file is signed, and the signer's certificate changes, the signature in the geofeed file MUST be updated.¶
It is good key hygiene to use a given key for only one purpose. To dedicate a signing private key for signing a geofeed file, an RPKI Certification Authority (CA) may issue a subordinate certificate exclusively for the purpose shown in Appendix A.¶
To minimize the load on RIR WHOIS [RFC3912] services, use of the RIR's FTP [RFC0959] services SHOULD be used for large-scale access to gather geofeed URLs. This also provides bulk access instead of fetching by brute-force search through the IP space.¶
Currently, geolocation providers have bulk WHOIS data access at all the RIRs. An anonymized version of such data is openly available for all RIRs except ARIN, which requires an authorization. However, for users without such authorization, the same result can be achieved with extra RDAP effort. There is open-source code to pass over such data across all RIRs, collect all geofeed references, and process them [GEOFEED-FINDER].¶
To prevent undue load on RPSL and geofeed servers, entity-fetching geofeed data using these mechanisms MUST NOT do frequent real-time lookups. Section 3.4 of [RFC8805] suggests use of the HTTP Expires header [RFC7234] to signal when geofeed data should be refetched. As the data change very infrequently, in the absence of such an HTTP Header signal, collectors SHOULD NOT fetch more frequently than weekly. It would be polite not to fetch at magic times such as midnight UTC, the first of the month, etc., because too many others are likely to do the same.¶
6. Privacy Considerations
[RFC8805] geofeed data may reveal the approximate location of an IP address, which might in turn reveal the approximate location of an individual user. Unfortunately, [RFC8805] provides no privacy guidance on avoiding or ameliorating possible damage due to this exposure of the user. In publishing pointers to geofeed files as described in this document, the operator should be aware of this exposure in geofeed data and be cautious. All the privacy considerations of Section 4 of [RFC8805] apply to this document.¶
Where [RFC8805] provided the ability to publish location data, this document makes bulk access to those data readily available. This is a goal, not an accident.¶
7. Security Considerations
It is generally prudent for a consumer of geofeed data to also use other sources to cross validate the data. All the security considerations of [RFC8805] apply here as well.¶
As mentioned in Section 4, many RPSL repositories have weak, if any, authentication. This allows spoofing of inetnum: objects pointing to malicious geofeed files. Section 4 suggests an unfortunately complex method for stronger authentication based on the RPKI.¶
For example, if an inetnum: for a wide address range (e.g., a /16) points to an RPKI-signed geofeed file, a customer or attacker could publish an unsigned equal or narrower (e.g., a /24) inetnum: in a WHOIS registry that has weak authorization, abusing the rule that the most-specific inetnum: object with a geofeed reference MUST be used.¶
If signatures were mandatory, the above attack would be stymied, but of course that is not happening anytime soon.¶
The RPSL providers have had to throttle fetching from their servers due to too-frequent queries. Usually, they throttle by the querying IP address or block. Similar defenses will likely need to be deployed by geofeed file servers.¶
8. IANA Considerations
IANA has registered object identifiers for one content
type in the "SMI Security for S/MIME CMS Content Type
9. References
9.1. Normative References
- [RFC2119]
-
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10
.17487 , , <https:///RFC2119 www >..rfc -editor .org /info /rfc2119 - [RFC2622]
-
Alaettinoglu, C., Villamizar, C., Gerich, E., Kessens, D., Meyer, D., Bates, T., Karrenberg, D., and M. Terpstra, "Routing Policy Specification Language (RPSL)", RFC 2622, DOI 10
.17487 , , <https:///RFC2622 www >..rfc -editor .org /info /rfc2622 - [RFC2725]
-
Villamizar, C., Alaettinoglu, C., Meyer, D., and S. Murphy, "Routing Policy System Security", RFC 2725, DOI 10
.17487 , , <https:///RFC2725 www >..rfc -editor .org /info /rfc2725 - [RFC2818]
-
Rescorla, E., "HTTP Over TLS", RFC 2818, DOI 10
.17487 , , <https:///RFC2818 www >..rfc -editor .org /info /rfc2818 - [RFC3629]
-
Yergeau, F., "UTF-8, a transformation format of ISO 10646", STD 63, RFC 3629, DOI 10
.17487 , , <https:///RFC3629 www >..rfc -editor .org /info /rfc3629 - [RFC3779]
-
Lynn, C., Kent, S., and K. Seo, "X.509 Extensions for IP Addresses and AS Identifiers", RFC 3779, DOI 10
.17487 , , <https:///RFC3779 www >..rfc -editor .org /info /rfc3779 - [RFC4012]
-
Blunk, L., Damas, J., Parent, F., and A. Robachevsky, "Routing Policy Specification Language next generation (RPSLng)", RFC 4012, DOI 10
.17487 , , <https:///RFC4012 www >..rfc -editor .org /info /rfc4012 - [RFC4648]
-
Josefsson, S., "The Base16, Base32, and Base64 Data Encodings", RFC 4648, DOI 10
.17487 , , <https:///RFC4648 www >..rfc -editor .org /info /rfc4648 - [RFC5280]
-
Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R., and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, DOI 10
.17487 , , <https:///RFC5280 www >..rfc -editor .org /info /rfc5280 - [RFC5652]
-
Housley, R., "Cryptographic Message Syntax (CMS)", STD 70, RFC 5652, DOI 10
.17487 , , <https:///RFC5652 www >..rfc -editor .org /info /rfc5652 - [RFC6481]
-
Huston, G., Loomans, R., and G. Michaelson, "A Profile for Resource Certificate Repository Structure", RFC 6481, DOI 10
.17487 , , <https:///RFC6481 www >..rfc -editor .org /info /rfc6481 - [RFC6486]
-
Austein, R., Huston, G., Kent, S., and M. Lepinski, "Manifests for the Resource Public Key Infrastructure (RPKI)", RFC 6486, DOI 10
.17487 , , <https:///RFC6486 www >..rfc -editor .org /info /rfc6486 - [RFC8174]
-
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10
.17487 , , <https:///RFC8174 www >..rfc -editor .org /info /rfc8174 - [RFC8805]
-
Kline, E., Duleba, K., Szamonek, Z., Moser, S., and W. Kumari, "A Format for Self-Published IP Geolocation Feeds", RFC 8805, DOI 10
.17487 , , <https:///RFC8805 www >..rfc -editor .org /info /rfc8805 - [RFC8933]
-
Housley, R., "Update to the Cryptographic Message Syntax (CMS) for Algorithm Identifier Protection", RFC 8933, DOI 10
.17487 , , <https:///RFC8933 www >..rfc -editor .org /info /rfc8933
9.2. Informative References
- [GEOFEED-FINDER]
-
"geofeed-finder", commit 5f557a4, , <https://
github >..com /massimocandela /geofeed -finder - [INET6NUM]
-
RIPE NCC, "Description of the INET6NUM Object", , <https://
www >..ripe .net /manage -ips -and -asns /db /support /documentation /ripe -database -documentation /rpsl -object -types /4 -2 -descriptions -of -primary -objects /4 -2 -3 -description -of -the -inet6num -object - [INETNUM]
-
RIPE NCC, "Description of the INETNUM Object", , <https://
www >..ripe .net /manage -ips -and -asns /db /support /documentation /ripe -database -documentation /rpsl -object -types /4 -2 -descriptions -of -primary -objects /4 -2 -4 -description -of -the -inetnum -object - [RFC0959]
-
Postel, J. and J. Reynolds, "File Transfer Protocol", STD 9, RFC 959, DOI 10
.17487 , , <https:///RFC0959 www >..rfc -editor .org /info /rfc959 - [RFC3912]
-
Daigle, L., "WHOIS Protocol Specification", RFC 3912, DOI 10
.17487 , , <https:///RFC3912 www >..rfc -editor .org /info /rfc3912 - [RFC4632]
-
Fuller, V. and T. Li, "Classless Inter-domain Routing (CIDR): The Internet Address Assignment and Aggregation Plan", BCP 122, RFC 4632, DOI 10
.17487 , , <https:///RFC4632 www >..rfc -editor .org /info /rfc4632 - [RFC5485]
-
Housley, R., "Digital Signatures on Internet-Draft Documents", RFC 5485, DOI 10
.17487 , , <https:///RFC5485 www >..rfc -editor .org /info /rfc5485 - [RFC7234]
-
Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching", RFC 7234, DOI 10
.17487 , , <https:///RFC7234 www >..rfc -editor .org /info /rfc7234 - [RFC7485]
-
Zhou, L., Kong, N., Shen, S., Sheng, S., and A. Servin, "Inventory and Analysis of WHOIS Registration Objects", RFC 7485, DOI 10
.17487 , , <https:///RFC7485 www >..rfc -editor .org /info /rfc7485 - [RFC7909]
-
Kisteleki, R. and B. Haberman, "Securing Routing Policy Specification Language (RPSL) Objects with Resource Public Key Infrastructure (RPKI) Signatures", RFC 7909, DOI 10
.17487 , , <https:///RFC7909 www >..rfc -editor .org /info /rfc7909 - [RFC9082]
-
Hollenbeck, S. and A. Newton, "Registration Data Access Protocol (RDAP) Query Format", STD 95, RFC 9082, DOI 10
.17487 , , <https:///RFC9082 www >..rfc -editor .org /info /rfc9082 - [RIPE-DB]
-
RIPE NCC, "RIPE Database Documentation", <https://
www >..ripe .net /manage -ips -and -asns /db /support /documentation /ripe -database -documentation - [RIPE181]
-
RIPE NCC, "Representation Of IP Routing Policies In A Routing Registry", , <https://
www >..ripe .net /publications /docs /ripe -181 - [RIPE81]
-
RIPE NCC, "Representation Of IP Routing Policies In The RIPE Database", , <https://
www >..ripe .net /publications /docs /ripe -081 - [RPKI-RSC]
-
Snijders, J., Harrison, T., and B. Maddison, "Resource Public Key Infrastructure (RPKI) object profile for Signed Checklist (RSC)", Work in Progress, Internet-Draft, draft
-ietf , , <https://-sidrops -rpki -rsc -04 datatracker >..ietf .org /doc /html /draft -ietf -sidrops -rpki -rsc -04 - [RPKI-RTA]
-
Michaelson, G. G., Huston, G., Harrison, T., Bruijnzeels, T., and M. Hoffmann, "A profile for Resource Tagged Attestations (RTAs)", Work in Progress, Internet-Draft, draft
-ietf , , <https://-sidrops -rpki -rta -00 datatracker >..ietf .org /doc /html /draft -ietf -sidrops -rpki -rta -00
Appendix A. Example
This appendix provides an example that includes a trust anchor, a CA certificate subordinate to the trust anchor, an end-entity certificate subordinate to the CA for signing the geofeed, and a detached signature.¶
The trust anchor is represented by a self-signed certificate. As usual in the RPKI, the trust anchor has authority over all IPv4 address blocks, all IPv6 address blocks, and all Autonomous System (AS) numbers.¶
The CA certificate is issued by the trust anchor. This certificate grants authority over one IPv4 address block (192.0.2.0/24) and two AS numbers (64496 and 64497).¶
The end-entity certificate is issued by the CA. This certificate grants signature authority for one IPv4 address block (192.0.2.0/24). Signature authority for AS numbers is not needed for geofeed data signatures, so no AS numbers are included in the certificate.¶
The end-entity certificate is displayed below in detail. For brevity, the other two certificates are not.¶
To allow reproduction of the signature results, the end-entity private key is provided. For brevity, the other two private keys are not.¶
Signing of "192
Acknowledgments
Thanks to Rob Austein for CMS and detached
signature clue, George Michaelson for the first
and substantial external review, and Erik Kline
who was too shy to agree to coauthorship. Additionally, we express
our gratitude to early implementors, including Menno Schepers; Flavio Luciani; Eric Dugas; Job Snijders, who
provided running code; and Kevin Pack. Also,
thanks to the following geolocation providers who are consuming geofeeds with this
described solution: Jonathan Kosgei (ipdata.co),
Ben Dowling (ipinfo.io), and Pol Nisenblat