Network Working Group J. Snijders Internet-Draft Fastly Intended status: Standards Track March 18, 2021 Expires: September 19, 2021 Resource Public Key Infrastructure (RPKI) object profile for Signed Checklist (RSC) draft-ietf-sidrops-rpki-rsc-02 Abstract This document defines a Cryptographic Message Syntax (CMS) profile for a general purpose listing of checksums (a 'checklist'), for use with the Resource Public Key Infrastructure (RPKI). The objective is to allow an attestation, in the form of a listing of one or more checksums of arbitrary digital objects (files), to be signed "with resources", and for validation to provide a means to confirm a specific Internet Resource Holder produced the Signed Checklist. The profile is intended to provide for the signing of an arbitrary checksum listing with a specific set of Internet Number Resources. 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. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on September 19, 2021. Snijders Expires September 19, 2021 [Page 1] Internet-Draft RPKI Signed Checklist March 2021 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://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. RSC Profile and Distribution . . . . . . . . . . . . . . . . 3 3. The RSC ContentType . . . . . . . . . . . . . . . . . . . . . 3 4. The RSC eContent . . . . . . . . . . . . . . . . . . . . . . 4 4.1. version . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.2. resources . . . . . . . . . . . . . . . . . . . . . . . . 5 4.3. digestAlgorithm . . . . . . . . . . . . . . . . . . . . . 5 4.4. checkList . . . . . . . . . . . . . . . . . . . . . . . . 5 5. Operational Considerations . . . . . . . . . . . . . . . . . 5 6. RSC Validation . . . . . . . . . . . . . . . . . . . . . . . 6 7. Security Considerations . . . . . . . . . . . . . . . . . . . 6 8. Implementation status - RFC EDITOR: REMOVE BEFORE PUBLICATION 6 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 9.1. OID . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 9.2. File Extension . . . . . . . . . . . . . . . . . . . . . 7 9.3. Media Type . . . . . . . . . . . . . . . . . . . . . . . 7 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 10.1. Normative References . . . . . . . . . . . . . . . . . . 8 10.2. Informative References . . . . . . . . . . . . . . . . . 9 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 10 Appendix B. Document changelog - RFC EDITOR: REMOVE BEFORE PUBLICATION . . . . . . . . . . . . . . . . . . . . 10 B.1. changes from -01 -> -02 . . . . . . . . . . . . . . . . . 10 B.2. changes from -00 -> -01 . . . . . . . . . . . . . . . . . 10 B.3. individual submission phase . . . . . . . . . . . . . . . 10 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 10 Snijders Expires September 19, 2021 [Page 2] Internet-Draft RPKI Signed Checklist March 2021 1. Introduction This document defines a Cryptographic Message Syntax (CMS) [RFC5652] profile for a general purpose listing of checksums (a 'checklist'), for use with the Resource Public Key Infrastructure (RPKI) [RFC6480]. The objective is to allow an attestation, in the form of a listing of one or more checksums of arbitrary files, to be signed "with resources", and for validation to provide a means to confirm a given Internet Resource Holder produced the RPKI Signed Checklist (RSC). The profile is intended to provide for the signing of a checksum listing with a specific set of Internet Number Resources. Signed Checklists are expected to facilitate inter-domain business use-cases which depend on an ability to verify resource holdership. RPKI-based validation processes are expected to become the industry norm for automated Bring Your Own IP (BYOIP) on-boarding or establishment of physical interconnection between Autonomous Systems. The RSC concept borrows heavily from RTA [I-D.ietf-sidrops-rpki-rta], Manifests [RFC6486], and OpenBSD's [signify] utility. The main difference between RSC and RTA is that the RTA profile allows multiple signers to attest a single digital object through a checksum of its content, while the RSC profile allows a single signer to attest the existence of multiple digital objects. A single signer profile is considered a simplification for both implementers and operators. 2. RSC Profile and Distribution RSC follows the Signed Object Template for the RPKI [RFC6488] with one exception. Because RSCs MUST NOT be distributed through the global RPKI repository system, the Subject Information Access (SIA) extension is omitted from the RSC's X.509 EE certificate. What constitutes suitable transport for RSC files is deliberately unspecified. It might be a USB stick, a web interface secured with conventional HTTPS, PGP-signed email, a T-shirt printed with a QR code, or a carrier pigeon. 3. The RSC ContentType The ContentType for an RSC is defined as rpkiSignedChecklist, and has the numerical value of 1.2.840.113549.1.9.16.1.TBD. This OID MUST appear both within the eContentType in the encapContentInfo object as well as the ContentType signed attribute in the signerInfo object (see [RFC6488]). Snijders Expires September 19, 2021 [Page 3] Internet-Draft RPKI Signed Checklist March 2021 4. The RSC eContent The content of an RSC indicates that a checklist for arbitrary digital objects has been signed "with resources". An RSC is formally defined as: RpkiSignedChecklist-2021 { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9) smime(16) mod(0) TBD } DEFINITIONS EXPLICIT TAGS ::= BEGIN IMPORTS CONTENT-TYPE, Digest, DigestAlgorithmIdentifier FROM CryptographicMessageSyntax-2009 -- in [RFC5911] { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) modules(0) id-mod-cms-2004-02(41) } ASIdOrRange, IPAddressFamily FROM IPAddrAndASCertExtn -- in [RFC3779] { iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) pkix(7) mod(0) id-mod-ip-addr-and-as-ident(30) } ; ct-rpkiSignedChecklist CONTENT-TYPE ::= { TYPE RpkiSignedChecklist IDENTIFIED BY id-ct-signedChecklist } id-ct-signedChecklist OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) id-smime(16) id-ct(1) TBD } RpkiSignedChecklist ::= SEQUENCE { version [0] INTEGER DEFAULT 0, resources ResourceBlock, digestAlgorithm DigestAlgorithmIdentifier, checkList SEQUENCE SIZE (1..MAX) OF FilenameAndHash } FilenameAndHash ::= SEQUENCE { filename IA5String OPTIONAL, hash Digest } ResourceBlock ::= SEQUENCE { asID [0] AsList OPTIONAL, ipAddrBlocks [1] IPList OPTIONAL } -- at least one of asID or ipAddrBlocks MUST be present ( WITH COMPONENTS { ..., asID PRESENT} | Snijders Expires September 19, 2021 [Page 4] Internet-Draft RPKI Signed Checklist March 2021 WITH COMPONENTS { ..., ipAddrBlocks PRESENT } ) AsList ::= SEQUENCE (SIZE(1..MAX)) OF ASIdOrRange IPList ::= SEQUENCE (SIZE(1..MAX)) OF IPAddressFamily END 4.1. version The version number of the RpkiSignedChecklist MUST be 0. 4.2. resources The resources contained here are the resources used to mark the attestation, and MUST match the set of resources listed by the EE certificate carried in the CMS certificates field. 4.3. digestAlgorithm The digest algorithm used to create the message digest of the attested digital object. This algorithm MUST be a hashing algorithm defined in [RFC7935]. 4.4. checkList This field is a sequence of FilenameAndHash objects. There is one FilenameAndHash entry for each arbitrary object referenced on the Signed Checklist. Each FilenameAndHash is an ordered pair of the name of the directory entry containing the digital object and the message digest of the digital object. The filename field is OPTIONAL. 5. Operational Considerations When creating digital objects of a plain-text nature (such as ASCII, UTF-8, HTML, Javascript, XML, etc) it is RECOMMENDED to convert such objects into a lossless compressed form. Distributing plain-text objects within a compression envelope (such as GZIP [RFC1952]) might help avoid unexpected canonicalization at intermediate systems (which in turn would lead to checksum verification errors). Validator implementations are expected to treat a checksummed digital object as string of arbitrary single octets. Snijders Expires September 19, 2021 [Page 5] Internet-Draft RPKI Signed Checklist March 2021 6. RSC Validation To validate an RSC the relying party MUST perform all the validation checks specified in [RFC6488] as well as the following additional RSC-specific validation steps. o The message digest of each referenced digital object, using the digest algorithm specified in the the digestAlgorithm field, MUST be calculated and MUST match the value given in the messageDigest field of the associated FileAndHash, for the RSC entry to be considered valid. o If a filename field is present, the field's content MUST contain only characters specified in the Portable Filename Character Set as defined in [POSIX]. 7. Security Considerations Relying parties are hereby warned that the data in a RPKI Signed Checklist is self-asserted. When determining the meaning of any data contained in an RPKI Signed Checklist, Relying Parties MUST NOT make any assuptions about the signer beyond the fact that it had sufficient control of the issuing CA to create the object. These data have not been verified by the Certificate Authority (CA) that issued the CA certificate to the entity that issued the EE certificate used to validate the Signed Checklist. RPKI Certificates are not bound to real world identities, see [I-D.ymbk-sidrops-rpki-has-no-identity] for an elaboration. Relying Parties can only associate real world entities to Internet Number Resources by additionally consulting an exogenous authority. Signed Checklists are a tool to communicate assertions 'signed with Internet Number Resources', not about any other aspect of the resource holder's business operations such as the identity of the resource holder itself. 8. Implementation status - RFC EDITOR: REMOVE BEFORE PUBLICATION This section records the status of known implementations of the protocol defined by this specification at the time of posting of this Internet-Draft, and is based on a proposal described in RFC 7942. The description of implementations in this section is intended to assist the IETF in its decision processes in progressing drafts to RFCs. Please note that the listing of any individual implementation here does not imply endorsement by the IETF. Furthermore, no effort has been spent to verify the information presented here that was supplied by IETF contributors. This is not intended as, and must not be construed to be, a catalog of available implementations or their Snijders Expires September 19, 2021 [Page 6] Internet-Draft RPKI Signed Checklist March 2021 features. Readers are advised to note that other implementations may exist. According to RFC 7942, "this will allow reviewers and working groups to assign due consideration to documents that have the benefit of running code, which may serve as evidence of valuable experimentation and feedback that have made the implemented protocols more mature. It is up to the individual working groups to use this information as they see fit". o A signer and validator implementation [rpki-rsc-demo] based on perl and OpenSSL was provided by Tom Harrison from APNIC. o A validator implementation based on OpenBSD's rpki-client is expected to be published after IANA Early Allocation of the OIDs. 9. IANA Considerations 9.1. OID The IANA has registered the OID for the RPKI Signed Checklist in the registry created by [RFC6488] as follows: Name OID Specification --------------------------------------------------------- Checklists 1.2.840.113549.1.9.16.1.TBD [RFC-TBD] 9.2. File Extension The IANA has added an item for the Signed Checklist file extension to the "RPKI Repository Name Scheme" created by [RFC6481] as follows: Filename Extension RPKI Object Reference ----------------------------------------------------------- .sig Signed Checklist [RFC-TBD] 9.3. Media Type The IANA has registered the media type application/rpki-checklist as follows: Snijders Expires September 19, 2021 [Page 7] Internet-Draft RPKI Signed Checklist March 2021 Type name: application Subtype name: rpki-checklist Required parameters: None Optional parameters: None Encoding considerations: binary Security considerations: Carries an RPKI Signed Checklist [RFC-TBD]. Interoperability considerations: None Published specification: This document. Applications that use this media type: RPKI operators. Additional information: Content: This media type is a signed object, as defined in [RFC6488], which contains a payload of a list of checksums as defined above in this document. Magic number(s): None File extension(s): .sig Macintosh file type code(s): Person & email address to contact for further information: Job Snijders Intended usage: COMMON Restrictions on usage: None Author: Job Snijders Change controller: Job Snijders 10. References 10.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70, RFC 5652, DOI 10.17487/RFC5652, September 2009, . [RFC6481] Huston, G., Loomans, R., and G. Michaelson, "A Profile for Resource Certificate Repository Structure", RFC 6481, DOI 10.17487/RFC6481, February 2012, . [RFC6486] Austein, R., Huston, G., Kent, S., and M. Lepinski, "Manifests for the Resource Public Key Infrastructure (RPKI)", RFC 6486, DOI 10.17487/RFC6486, February 2012, . Snijders Expires September 19, 2021 [Page 8] Internet-Draft RPKI Signed Checklist March 2021 [RFC6488] Lepinski, M., Chi, A., and S. Kent, "Signed Object Template for the Resource Public Key Infrastructure (RPKI)", RFC 6488, DOI 10.17487/RFC6488, February 2012, . [RFC7935] Huston, G. and G. Michaelson, Ed., "The Profile for Algorithms and Key Sizes for Use in the Resource Public Key Infrastructure", RFC 7935, DOI 10.17487/RFC7935, August 2016, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 10.2. Informative References [I-D.ietf-sidrops-rpki-rta] Michaelson, G., Huston, G., Harrison, T., Bruijnzeels, T., and M. Hoffmann, "A profile for Resource Tagged Attestations (RTAs)", draft-ietf-sidrops-rpki-rta-00 (work in progress), January 2021. [I-D.ymbk-sidrops-rpki-has-no-identity] Bush, R. and R. Housley, "The I in RPKI does not stand for Identity", draft-ymbk-sidrops-rpki-has-no-identity-00 (work in progress), March 2021. [POSIX] IEEE and The Open Group, "The Open Group's Base Specifications, Issue 7", 2016, . [RFC1952] Deutsch, P., "GZIP file format specification version 4.3", RFC 1952, DOI 10.17487/RFC1952, May 1996, . [RFC6480] Lepinski, M. and S. Kent, "An Infrastructure to Support Secure Internet Routing", RFC 6480, DOI 10.17487/RFC6480, February 2012, . [rpki-rsc-demo] Harrison, T., "A proof-of-concept for constructing and validating RPKI Signed Checklists (RSCs).", February 2021, . [signify] Unangst, T. and M. Espie, "signify - cryptographically sign and verify files", May 2014, . Snijders Expires September 19, 2021 [Page 9] Internet-Draft RPKI Signed Checklist March 2021 Appendix A. Acknowledgements The author wishes to thank George Michaelson, Tom Harrison, Geoff Huston, Randy Bush, Stephen Kent, Matt Lepinski, Rob Austein, Ted Unangst, and Marc Espie for prior art. The author thanks Russ Housley for reviewing the ASN.1 notation and providing suggestions. The author would like to thank Nimrod Levy, Tom Harrison, Ben Maddison, and Tim Bruijnzeels for document review and suggestions. Appendix B. Document changelog - RFC EDITOR: REMOVE BEFORE PUBLICATION B.1. changes from -01 -> -02 o Clarify RSC is part of a puzzle, not panacea. Thanks Randy & Russ B.2. changes from -00 -> -01 o Readability improvements o Update document category to match the registry allocation policy requirement. B.3. individual submission phase o On-the-wire change: the 'Filename' switched from 'required' to 'optional'. Some SIDROPS Working Group participants proposed a checksum itself is the most minimal information required to address digital objects. Author's Address Job Snijders Fastly Amsterdam Netherlands Email: job@fastly.com Snijders Expires September 19, 2021 [Page 10]