Network Working Group J. Snijders Internet-Draft Fastly Intended status: Informational February 20, 2021 Expires: August 24, 2021 RPKI Signed Checklists draft-spaghetti-sidrops-rpki-rsc-03 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 a checksum listing with an arbitrary 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 August 24, 2021. Snijders Expires August 24, 2021 [Page 1]
Internet-Draft RPKI Signed Checklists February 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 . . . . . . . . . . . . . . . . . . . . . . . . 2 2. RSC Profile and Distribution . . . . . . . . . . . . . . . . 3 3. The RSC ContentType . . . . . . . . . . . . . . . . . . . . . 3 4. The RSC eContent . . . . . . . . . . . . . . . . . . . . . . 3 4.1. version . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.2. resources . . . . . . . . . . . . . . . . . . . . . . . . 5 4.3. digestAlgorithm . . . . . . . . . . . . . . . . . . . . . 5 4.4. checkList . . . . . . . . . . . . . . . . . . . . . . . . 5 5. Operational Considerations . . . . . . . . . . . . . . . . . 5 6. RSC Validation . . . . . . . . . . . . . . . . . . . . . . . 5 7. Security Considerations . . . . . . . . . . . . . . . . . . . 6 8. Implementation status - RFC EDITOR: REMOVE BEFORE PUBLICATION 6 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 9.1. OID . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 9.2. File Extension . . . . . . . . . . . . . . . . . . . . . 7 9.3. Media Type . . . . . . . . . . . . . . . . . . . . . . . 7 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 10.1. Normative References . . . . . . . . . . . . . . . . . . 7 10.2. Informative References . . . . . . . . . . . . . . . . . 8 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 9 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 9 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). Snijders Expires August 24, 2021 [Page 2]
Internet-Draft RPKI Signed Checklists February 2021 The profile is intended to provide for the signing of a checksum listing with an arbitrary set of Internet Number Resources. RSC files are expected to facilitate Bring Your Own IP (BYOIP) authentication, inter-domain interconnection provisioning, and resource holdership verification processes. 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 an RTA enables multiple signers to attest a single anonymous digital object through a checksum of its content, while an RSC allows a single signer to attest the checksums of multiple named digital objects. This difference is expected to represent a simplification for 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]). 4. The RSC eContent The content of an RSC indicates that an a checklist for arbitrary named 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 ::= Snijders Expires August 24, 2021 [Page 3]
Internet-Draft RPKI Signed Checklists February 2021 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 FileAndHash } FileAndHash ::= SEQUENCE { file 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} | WITH COMPONENTS { ..., ipAddrBlocks PRESENT } ) AsList ::= SEQUENCE (SIZE(1..MAX)) OF ASIdOrRange IPList ::= SEQUENCE (SIZE(1..MAX)) OF IPAddressFamily END Snijders Expires August 24, 2021 [Page 4]
Internet-Draft RPKI Signed Checklists February 2021 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 FileAndHash objects. There is one FileAndHash entry for each arbitrary object referenced from the RSC. Each FileAndHash is an ordered pair consisting an optional name of the file containing the object, and the message digest of the digital object. 5. Operational Considerations When working with objects of a plain-text nature (ASCII, UTF-8, HTML, Javascript, XML, etc) it is RECOMMENDED to distribute such objects in a lossless compressed form, and sign the compressed form. Wrapping plain-text objects in a compression envelope can help make those appear as a single octet string to any intermediate systems, which hopefully discourages in-transit modification of the file contents. The use of lossless compression can help avoid checksum verification errors. 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. o If a filename is present, the filename MUST NOT contain a '/' (slash) or '\' (backslash) character. Snijders Expires August 24, 2021 [Page 5]
Internet-Draft RPKI Signed Checklists February 2021 7. Security Considerations Relying parties are hereby warned that the data in a RPKI Signed Checklist is self-asserted. These data have not been verified by the CA that issued the CA certificate to the entity that issued the EE certificate used to validate the Signed Checklist. 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 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] Snijders Expires August 24, 2021 [Page 6]
Internet-Draft RPKI Signed Checklists February 2021 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: 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 <job@fastly.com> Intended usage: COMMON Restrictions on usage: None Author: Job Snijders <job@fastly.com> Change controller: Job Snijders <job@fastly.com> 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, <https://www.rfc-editor.org/info/rfc2119>. Snijders Expires August 24, 2021 [Page 7]
Internet-Draft RPKI Signed Checklists February 2021 [RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70, RFC 5652, DOI 10.17487/RFC5652, September 2009, <https://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/RFC6481, February 2012, <https://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/RFC6486, February 2012, <https://www.rfc-editor.org/info/rfc6486>. [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, <https://www.rfc-editor.org/info/rfc6488>. [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, <https://www.rfc-editor.org/info/rfc7935>. [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <https://www.rfc-editor.org/info/rfc8174>. 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. [RFC6480] Lepinski, M. and S. Kent, "An Infrastructure to Support Secure Internet Routing", RFC 6480, DOI 10.17487/RFC6480, February 2012, <https://www.rfc-editor.org/info/rfc6480>. [rpki-rsc-demo] Harrison, T., "A proof-of-concept for constructing and validating RPKI Signed Checklists (RSCs).", February 2021, <https://github.com/APNIC-net/rpki-rsc-demo>. [signify] Unangst, T. and M. Espie, "signify - cryptographically sign and verify files", May 2014, <https://man.openbsd.org/signify>. Snijders Expires August 24, 2021 [Page 8]
Internet-Draft RPKI Signed Checklists February 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. Author's Address Job Snijders Fastly Amsterdam Netherlands Email: job@fastly.com Snijders Expires August 24, 2021 [Page 9]