path: root/doc/rfc/rfc9286.txt

Internet Engineering Task Force (IETF)                        R. Austein
Request for Comments: 9286                                  Arrcus, Inc.
Obsoletes: 6486                                                G. Huston
Category: Standards Track                                          APNIC
ISSN: 2070-1721                                                  S. Kent
                                                             Independent
                                                             M. Lepinski
                                                     New College Florida
                                                               June 2022


      Manifests for the Resource Public Key Infrastructure (RPKI)

Abstract

   This document defines a "manifest" for use in the Resource Public Key
   Infrastructure (RPKI).  A manifest is a signed object (file) that
   contains a listing of all the signed objects (files) in the
   repository publication point (directory) associated with an authority
   responsible for publishing in the repository.  For each certificate,
   Certificate Revocation List (CRL), or other type of signed objects
   issued by the authority that are published at this repository
   publication point, the manifest contains both the name of the file
   containing the object and a hash of the file content.  Manifests are
   intended to enable a relying party (RP) to detect certain forms of
   attacks against a repository.  Specifically, if an RP checks a
   manifest's contents against the signed objects retrieved from a
   repository publication point, then the RP can detect replay attacks,
   and unauthorized in-flight modification or deletion of signed
   objects.  This document obsoletes RFC 6486.

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://www.rfc-editor.org/info/rfc9286.

Copyright Notice

   Copyright (c) 2022 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 Revised BSD License text as described in Section 4.e of the
   Trust Legal Provisions and are provided without warranty as described
   in the Revised BSD License.

Table of Contents

   1.  Introduction
     1.1.  Requirements Language
   2.  Manifest Scope
   3.  Manifest Signing
   4.  Manifest Definition
     4.1.  eContentType
     4.2.  eContent
       4.2.1.  Manifest
       4.2.2.  Names in FileAndHash Objects
     4.3.  Content-Type Attribute
     4.4.  Manifest Validation
   5.  Manifest Generation
     5.1.  Manifest Generation Procedure
     5.2.  Considerations for Manifest Generation
   6.  Relying Party Processing of Manifests
     6.1.  Manifest Processing Overview
     6.2.  Acquiring a Manifest for a CA
     6.3.  Detecting Stale and/or Prematurely Issued Manifests
     6.4.  Acquiring Files Referenced by a Manifest
     6.5.  Matching File Names and Hashes
     6.6.  Failed Fetches
   7.  Publication Repositories
   8.  Security Considerations
   9.  IANA Considerations
   10. References
     10.1.  Normative References
     10.2.  Informative References
   Appendix A.  ASN.1 Module
   Appendix B.  Changes since RFC 6486
   Acknowledgements
   Authors' Addresses

1.  Introduction

   The Resource Public Key Infrastructure (RPKI) [RFC6480] makes use of
   a distributed repository system [RFC6481] to make available a variety
   of objects needed by relying parties (RPs).  Because all of the
   objects stored in the repository system are digitally signed by the
   entities that created them, attacks that modify these published
   objects are detectable by RPs.  However, digital signatures alone
   provide no protection against attacks that substitute "stale"
   versions of signed objects (i.e., objects that were valid and have
   not yet expired, but have since been superseded), or in-flight
   attacks that remove an object that should be present in the
   repository.  To assist in the detection of such attacks, RPKI
   repository systems make use of a signed object called a "manifest".

   A manifest is a signed object that enumerates all the signed objects
   (files) in the repository publication point (directory) that are
   associated with an authority responsible for publishing at that
   publication point.  Each manifest contains both the name of the file
   containing the object and a hash of the file content, for every
   signed object issued by an authority that is published at the
   authority's repository publication point.  A manifest is intended to
   allow an RP to detect unauthorized object removal or the substitution
   of stale versions of objects at a publication point.  A manifest also
   is intended to allow an RP to detect similar outcomes that may result
   from an on-path attack during the retrieval of objects from the
   repository.  Manifests are intended to be used in Certification
   Authority (CA) publication points in repositories (directories
   containing files that are subordinate certificates and Certificate
   Revocation Lists (CRLs) issued by this CA and other signed objects
   that are verified by End-Entity (EE) certificates issued by this CA).

   Manifests are modeled on CRLs, as the issues involved in detecting
   stale manifests and potential attacks using manifest replays, etc.,
   are similar to those for CRLs.  The syntax of the manifest payload
   differs from CRLs, since RPKI repositories contain objects not
   covered by CRLs, e.g., digitally signed objects, such as Route Origin
   Authorizations (ROAs) [RFC6482].

   This document obsoletes [RFC6486].

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.  Manifest Scope

   A manifest associated with a CA's repository publication point
   contains a list of:

   *  the set of (non-expired, non-revoked) certificates issued and
      published by this CA,

   *  the most recent CRL issued by this CA, and

   *  all published signed objects that are verifiable using EE
      certificates [RFC6487] issued by this CA (other than the manifest
      itself).

   Every RPKI signed object includes, in the Cryptographic Message
   Syntax (CMS) [RFC5652] wrapper of the object, the EE certificate used
   to verify it [RFC6488].  Thus, there is no requirement to separately
   publish that EE certificate at the CA's repository publication point.

   Where multiple CA instances share a common publication point, as can
   occur when a CA performs a key-rollover operation [RFC6489], the
   repository publication point will contain multiple manifests.  In
   this case, each manifest describes only the collection of published
   products of its associated CA instance.

3.  Manifest Signing

   A CA's manifest is verified using an EE certificate.  The
   SubjectInfoAccess (SIA) field of this EE certificate contains the
   accessMethod Object Identifier (OID) of id-ad-signedObject.

   The CA MUST sign only one manifest with each generated private key
   and MUST generate a new key pair for each new version of the
   manifest.  An associated EE certificate used in this fashion is
   termed a "one-time-use" EE certificate (see Section 3 of [RFC6487]).

4.  Manifest Definition

   A manifest is an RPKI signed object, as specified in [RFC6488].  The
   RPKI signed object template requires specification of the following
   data elements in the context of the manifest structure.

4.1.  eContentType

   The eContentType for a manifest is defined as id-ct-rpkiManifest and
   has the numerical OID of 1.2.840.113549.1.9.16.1.26.

      id-smime OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840)
                                rsadsi(113549) pkcs(1) pkcs9(9) 16 }

      id-ct OBJECT IDENTIFIER ::= { id-smime 1 }

      id-ct-rpkiManifest OBJECT IDENTIFIER ::= { id-ct 26 }

4.2.  eContent

   The content of a manifest is ASN.1 encoded using the Distinguished
   Encoding Rules (DER) [X.690].  The content of a manifest is defined
   as follows:

       Manifest ::= SEQUENCE {
        version     [0] INTEGER DEFAULT 0,
        manifestNumber  INTEGER (0..MAX),
        thisUpdate      GeneralizedTime,
        nextUpdate      GeneralizedTime,
        fileHashAlg     OBJECT IDENTIFIER,
        fileList        SEQUENCE SIZE (0..MAX) OF FileAndHash
        }

      FileAndHash ::=     SEQUENCE {
        file            IA5String,
        hash            BIT STRING
     }

4.2.1.  Manifest

   The manifestNumber, thisUpdate, and nextUpdate fields are modeled
   after the corresponding fields in X.509 CRLs (see [RFC5280]).
   Analogous to CRLs, a manifest is nominally current until the time
   specified in nextUpdate or until a manifest is issued with a greater
   manifest number, whichever comes first.

   Because a "one-time-use" EE certificate is employed to verify a
   manifest, the EE certificate MUST be issued with a validity period
   that coincides with the interval from thisUpdate to nextUpdate in the
   manifest, to prevent needless growth of the CA's CRL.

   The data elements of the manifest structure are defined as follows:

   version:
      The version number of this version of the manifest specification
      MUST be 0.

   manifestNumber:
      This field is an integer that is incremented (by 1) each time a
      new manifest is issued for a given publication point.  This field
      allows an RP to detect gaps in a sequence of published manifests.

      As the manifest is modeled on the CRL specification, the
      manifestNumber is analogous to the CRLNumber, and the guidance in
      [RFC5280] for CRLNumber values is appropriate as to the range of
      number values that can be used for the manifestNumber.  Manifest
      numbers can be expected to contain long integers.  Manifest
      verifiers MUST be able to process number values up to 20 octets.
      Conforming manifest issuers MUST NOT use number values longer than
      20 octets.  The issuer MUST increase the value of this field
      monotonically for each newly generated manifest.  Each RP MUST
      verify that a purported "new" manifest contains a higher
      manifestNumber than previously validated manifests.  If the
      purported "new" manifest contains a manifestNumber value equal to
      or lower than manifestNumber values of previously validated
      manifests, the RP SHOULD use locally cached versions of objects,
      as described in Section 6.6.

   thisUpdate:
      This field contains the time when the manifest was created.  This
      field has the same format constraints as specified in [RFC5280]
      for the CRL field of the same name.  The issuer MUST ensure that
      the value of this field is more recent than any previously
      generated manifest.  Each RP MUST verify that this field value is
      greater (more recent) than the most recent manifest it has
      validated.  If this field in a purported "new" manifest is smaller
      (less recent) than previously validated manifests, the RP SHOULD
      use locally cached versions of objects, as described in
      Section 6.6.

   nextUpdate:
      This field contains the time at which the next scheduled manifest
      will be issued.  The value of nextUpdate MUST be later than the
      value of thisUpdate.  The specification of the GeneralizedTime
      value is the same as required for the thisUpdate field.

      If the authority alters any of the items that it has published in
      the repository publication point, then the authority MUST issue a
      new manifest.  Even if no changes are made to objects at a
      publication point, a new manifest MUST be issued before the
      nextUpdate time.  Each manifest encompasses a CRL, and the
      nextUpdate field of the manifest SHOULD match that of the CRL's
      nextUpdate field, as the manifest will be reissued when a new CRL
      is published.  When a new manifest is issued before the time
      specified in nextUpdate of the current manifest, the CA MUST also
      issue a new CRL that revokes the EE certificate corresponding to
      the old manifest.

   fileHashAlg:
      This field contains the OID of the hash algorithm used to hash the
      files that the authority has placed into the repository.  The hash
      algorithm used MUST conform to the RPKI Algorithms and Key Size
      Profile specification [RFC7935].

   fileList:
      This field is a sequence of FileAndHash objects.  There is one
      FileAndHash entry for each currently valid signed object that has
      been published by the authority (at this publication point).  Each
      FileAndHash is an ordered pair consisting of the name of the file
      in the repository publication point (directory) that contains the
      object in question and a hash of the file's contents.

4.2.2.  Names in FileAndHash Objects

   Names that appear in the fileList MUST consist of one or more
   characters chosen from the set a-z, A-Z, 0-9, - (HYPHEN), or
   _ (UNDERSCORE), followed by a single . (DOT), followed by a three-
   letter extension.  The extension MUST be one of those enumerated in
   the "RPKI Repository Name Schemes" registry maintained by IANA
   [IANA-NAMING].

   As an example, 'vixxBTS_TVXQ-2pmGOT7.cer' is a valid file name.

   The example above contains a mix of uppercase and lowercase
   characters in the file name.  CAs and RPs MUST be able to perform
   filesystem operations in a case-sensitive, case-preserving manner.

4.3.  Content-Type Attribute

   The mandatory content-type attribute MUST have its attrValues field
   set to the same OID as eContentType.  This OID is id-ct-rpkiManifest
   and has the numerical value of 1.2.840.113549.1.9.16.1.26.

4.4.  Manifest Validation

   To determine whether a manifest is valid, the RP MUST perform the
   following checks in addition to those specified in [RFC6488]:

   1.  The eContentType in the EncapsulatedContentInfo is id-ad-
       rpkiManifest (OID 1.2.840.113549.1.9.16.1.26).

   2.  The version of the rpkiManifest is 0.

   3.  In the rpkiManifest, thisUpdate precedes nextUpdate.

   Note: Although the thisUpdate and nextUpdate fields in the manifest
   eContent MUST match the corresponding fields in the CRL associated
   with the manifest, RPs MUST NOT reject a manifest solely because
   these fields are not identical.

   If the above procedure indicates that the manifest is invalid, then
   the manifest MUST be discarded and treated as though no manifest were
   present.

5.  Manifest Generation

5.1.  Manifest Generation Procedure

   For a CA publication point in the RPKI repository system, a CA MUST
   perform the following steps to generate a manifest:

   1.  Generate a new key pair for use in a "one-time-use" EE
       certificate.

   2.  Issue an EE certificate for this key pair.  The CA MUST revoke
       the EE certificate used for the manifest being replaced.

       This EE certificate MUST have an SIA extension access description
       field with an accessMethod OID value of id-ad-signedObject, where
       the associated accessLocation references the publication point of
       the manifest as an object URL.  (RPs are required to verify both
       of these syntactic constraints.)

       This EE certificate MUST describe its Internet Number Resources
       (INRs) using the "inherit" attribute, rather than an explicit
       description of a resource set (see [RFC3779]).  (RPs are required
       to verify this.)

       The validity interval of the EE certificate MUST exactly match
       the thisUpdate and nextUpdate times specified in the manifest's
       eContent.  (An RP MUST NOT consider misalignment of the validity
       interval in and of itself to be an error.)

   3.  The EE certificate MUST NOT be published in the authority's
       repository publication point.

   4.  Construct the manifest content.

       The manifest content is described in Section 4.2.1.  The
       manifest's fileList includes the file name and hash pair for each
       object issued by this CA that has been published at this
       repository publication point (directory).  The collection of
       objects to be included in the manifest includes all certificates
       issued by this CA that are published at the CA's repository
       publication point, the most recent CRL issued by the CA, and all
       objects verified by EE certificates that were issued by this CA
       that are published at this repository publication point.
       (Sections 6.1 through 6.5 describe the checks that an RP MUST
       perform in support of the manifest content noted here.)

       Note that the manifest does not include a self reference (i.e.,
       its own file name and hash), since it would be impossible to
       compute the hash of the manifest itself prior to it being signed.

   5.  Encapsulate the manifest content using the CMS SignedData content
       type (as specified in Section 4), sign the manifest using the
       private key corresponding to the subject key contained in the EE
       certificate, and publish the manifest in the repository system
       publication point that is described by the manifest.  (RPs are
       required to verify the CMS signature.)

   6.  Because the key pair is to be used only once, the private key
       associated with this key pair MUST now be destroyed.

5.2.  Considerations for Manifest Generation

   A new manifest MUST be issued and published before the nextUpdate
   time.

   An authority MUST issue a new manifest in conjunction with the
   finalization of changes made to objects in the publication point.  If
   any named objects in the publication point are replaced, the
   authority MUST ensure that the file hash for each replaced object is
   updated accordingly in the new manifest.  Additionally, the authority
   MUST revoke the certificate associated with each replaced object
   (other than a CRL), if it is not expired.  An authority MAY perform a
   number of object operations on a publication repository within the
   scope of a repository change before issuing a single manifest that
   covers all the operations within the scope of this change.
   Repository operators MUST implement some form of repository update
   procedure that mitigates, to the extent possible, the risk that RPs
   that are performing retrieval operations on the repository are
   exposed to inconsistent, transient, intermediate states during
   updates to the repository publication point (directory) and the
   associated manifest.

   Since the manifest object URL is included in the SIA of issued
   certificates, a new manifest MUST NOT invalidate the manifest object
   URL of previously issued certificates.  This implies that the
   manifest's publication name in the repository, in the form of an
   object URL, is unchanged across manifest generation cycles.

   When a CA entity is performing a key rollover, the entity MAY choose
   to have two CA instances simultaneously publishing into the same
   repository publication point.  In this case, there will be one
   manifest associated with each active CA instance that is publishing
   into the common repository publication point (directory).

6.  Relying Party Processing of Manifests

   Each RP MUST use the current manifest of a CA to control addition of
   listed files to the set of signed objects the RP employs for
   validating basic RPKI objects: certificates, ROAs, and CRLs.  Any
   files not listed on the manifest MUST NOT be used for validation of
   these objects.  However, files not listed on a manifest MAY be
   employed to validate other signed objects, if the profile of the
   object type explicitly states that such behavior is allowed (or
   required).  Note that relying on files not listed in a manifest may
   allow an attacker to effect substitution attacks against such
   objects.

   As noted earlier, manifests are designed to allow an RP to detect
   manipulation of repository data, errors by a CA or repository
   manager, and/or active attacks on the communication channel between
   an RP and a repository.  Unless all of the files enumerated in a
   manifest can be obtained by an RP during a fetch operation, the fetch
   is considered to have failed and the RP MUST retry the fetch later.

   [RFC6480] suggests (but does not mandate) that the RPKI model employ
   fetches that are incremental, e.g., an RP transfers files from a
   publication point only if they are new/changed since the previous,
   successful fetch represented in the RP's local cache.  This document
   avoids language that relies on details of the underlying file
   transfer mechanism employed by an RP and a publication point to
   effect this operation.  Thus, the term "fetch" refers to an operation
   that attempts to acquire the full set of files at a publication
   point, consistent with the id-ad-rpkiManifest URI extracted from a CA
   certificate's SIA (see below).

   If a fetch fails, it is assumed that a subsequent fetch will resolve
   problems encountered during the fetch.  Until such time as a
   successful fetch is executed, an RP SHOULD use cached data from a
   previous, successful fetch.  This response is intended to prevent an
   RP from misinterpreting data associated with a publication point and
   thus possibly treating invalid routes as valid, or vice versa.

   The processing described below is designed to cause all RPs with
   access to the same local cache and RPKI repository data to acquire
   the same set of validated repository files.  It does not ensure that
   the RPs will achieve the same results with regard to validation of
   RPKI data, since that depends on how each RP resolves any conflicts
   that may arise in processing the retrieved files.  Moreover, in
   operation, different RPs will access repositories at different times,
   and some RPs may experience local cache failures, so there is no
   guarantee that all RPs will achieve the same results with regard to
   acquisition or validation of RPKI data.

   Note also that there is a "chicken and egg" relationship between the
   manifest and the CRL for a given CA instance.  If the EE certificate
   for the current manifest is revoked, i.e., it appears in the current
   CRL, then the CA or publication point manager has made a serious
   error.  In this case, the fetch has failed; proceed to Section 6.6.
   Similarly, if the CRL is not listed on a valid, current manifest,
   acquired during a fetch, the fetch has failed; proceed to
   Section 6.6, because the CRL is considered missing.

6.1.  Manifest Processing Overview

   For a given publication point, an RP MUST perform a series of tests
   to determine which signed object files at the publication point are
   acceptable.  The tests described below (Sections 6.2 through 6.5) are
   to be performed using the manifest identified by the id-ad-
   rpkiManifest URI extracted from a CA certificate's SIA.  All of the
   files referenced by the manifest MUST be located at the publication
   point specified by the id-ad-caRepository URI from the (same) CA
   certificate's SIA.  The manifest and the files it references MUST
   reside at the same publication point.  If an RP encounters any files
   that appear on a manifest but do not reside at the same publication
   point as the manifest, the RP MUST treat the fetch as failed, and a
   warning MUST be issued (see Section 6.6 below).

   Note that, during CA key rollover [RFC6489], signed objects for two
   or more different CA instances will appear at the same publication
   point.  Manifest processing is to be performed separately for each CA
   instance, guided by the SIA id-ad-rpkiManifest URI in each CA
   certificate.

6.2.  Acquiring a Manifest for a CA

   The RP MUST fetch the manifest identified by the SIA id-ad-
   rpkiManifest URI in the CA certificate.  If an RP cannot retrieve a
   manifest using this URI or if the manifest is not valid
   (Section 4.4), an RP MUST treat this as a failed fetch; proceed to
   Section 6.6.  Otherwise, proceed to Section 6.3.

6.3.  Detecting Stale and/or Prematurely Issued Manifests

   The RP MUST check that the current time (translated to UTC) is
   between thisUpdate and nextUpdate.  If the current time lies within
   this interval, proceed to Section 6.4.  If the current time is
   earlier than thisUpdate, the CA may have made an error or the RP's
   local notion of time may be in error.  The RP MUST treat this as a
   failed fetch; proceed to Section 6.6.  If the current time is later
   than nextUpdate, then the manifest is stale; the RP MUST treat this
   as a failed fetch.  Proceed to Section 6.6.  Otherwise, proceed to
   Section 6.4.

6.4.  Acquiring Files Referenced by a Manifest

   The RP MUST acquire all of the files enumerated in the manifest
   (fileList) from the publication point.  If there are files listed in
   the manifest that cannot be retrieved from the publication point, the
   RP MUST treat this as a failed fetch.  Proceed to Section 6.6.
   Otherwise, proceed to Section 6.5.

6.5.  Matching File Names and Hashes

   The RP MUST verify that the hash value of each file listed in the
   manifest matches the value obtained by hashing the file acquired from
   the publication point.  If the computed hash value of a file listed
   on the manifest does not match the hash value contained in the
   manifest, then the fetch has failed, and the RP MUST respond
   accordingly.  Proceed to Section 6.6.

6.6.  Failed Fetches

   If a fetch fails for any of the reasons cited in Sections 6.2 through
   6.5, the RP MUST issue a warning indicating the reason(s) for
   termination of processing with regard to this CA instance.  It is
   RECOMMENDED that a human operator be notified of this warning.

   Termination of processing means that the RP SHOULD continue to use
   cached versions of the objects associated with this CA instance,
   until such time as they become stale or they can be replaced by
   objects from a successful fetch.  This implies that the RP MUST NOT
   try to acquire and validate subordinate signed objects, e.g.,
   subordinate CA certificates, until the next interval when the RP is
   scheduled to fetch and process data for this CA instance.

7.  Publication Repositories

   The RPKI publication system model requires that every publication
   point be associated with one or more CAs and be non-empty.  Upon
   creation of the publication point associated with a CA, the CA MUST
   create and publish a manifest as well as a CRL.  A CA's manifest will
   always contain at least one entry, i.e., a CRL issued by the CA
   [RFC6481], corresponding to the scope of this manifest.

   Every published signed object in the RPKI [RFC6488] is published in
   the repository publication point of the CA that issued the EE
   certificate, and is listed in the manifest associated with that CA
   certificate.

8.  Security Considerations

   Manifests provide an additional level of protection for RPKI RPs.
   Manifests can assist an RP in determining if a repository object has
   been deleted, occluded, or otherwise removed from view, or if a
   publication of a newer version of an object has been suppressed (and
   an older version of the object has been substituted).

   Manifests cannot repair the effects of such forms of corruption of
   repository retrieval operations.  However, a manifest enables an RP
   to determine if a locally maintained copy of a repository is a
   complete and up-to-date copy, even when the repository retrieval
   operation is conducted over an insecure channel.  In cases where the
   manifest and the retrieved repository contents differ, the manifest
   can assist in determining which repository objects form the
   difference set in terms of missing, extraneous, or superseded
   objects.

   The signing structure of a manifest and the use of the nextUpdate
   value allow an RP to determine if the manifest itself is the subject
   of attempted alteration.  The requirement for every repository
   publication point to contain at least one manifest allows an RP to
   determine if the manifest itself has been occluded from view.  Such
   attacks against the manifest are detectable within the time frame of
   the regular schedule of manifest updates.  Forms of replay attacks
   within finer-grained time frames are not necessarily detectable by
   the manifest structure.

9.  IANA Considerations

   The "RPKI Signed Objects" registry was originally created and
   populated by [RFC6488].  The "RPKI Repository Name Schemes" registry
   was created by [RFC6481] and created four of the initial three-letter
   file name extensions.  IANA has updated the reference for the
   "Manifest" row in the "RPKI Signed Objects" registry to point to this
   document.

   IANA has also updated the following entries to refer to this document
   instead of RFC 6486:

   *  id-mod-rpkiManifest (60) in the "SMI Security for S/MIME Module
      Identifier (1.2.840.113549.1.9.16.0)" registry

   *  id-ct-rpkiManifest (26) in the "SMI Security for S/MIME CMS
      Content Type (1.2.840.113549.1.9.16.1)" registry

   *  the "Security considerations" entry in the application media type
      registration for rpki-manifest

   No other actions are required.

10.  References

10.1.  Normative References

   [IANA-NAMING]
              IANA, "RPKI Repository Name Schemes",
              <https://www.iana.org/assignments/rpki/>.

   [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>.

   [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/RFC5280, May 2008,
              <https://www.rfc-editor.org/info/rfc5280>.

   [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>.

   [RFC6482]  Lepinski, M., Kent, S., and D. Kong, "A Profile for Route
              Origin Authorizations (ROAs)", RFC 6482,
              DOI 10.17487/RFC6482, February 2012,
              <https://www.rfc-editor.org/info/rfc6482>.

   [RFC6487]  Huston, G., Michaelson, G., and R. Loomans, "A Profile for
              X.509 PKIX Resource Certificates", RFC 6487,
              DOI 10.17487/RFC6487, February 2012,
              <https://www.rfc-editor.org/info/rfc6487>.

   [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>.

   [X.690]    International Telecommunication Union, "Information
              technology - ASN.1 encoding rules: Specification of Basic
              Encoding Rules (BER), Canonical Encoding Rules (CER) and
              Distinguished Encoding Rules (DER)", ITU-T Recommendation
              X.690, February 2021,
              <https://www.itu.int/rec/T-REC-X.690-202102-I/en>.

10.2.  Informative References

   [RFC3779]  Lynn, C., Kent, S., and K. Seo, "X.509 Extensions for IP
              Addresses and AS Identifiers", RFC 3779,
              DOI 10.17487/RFC3779, June 2004,
              <https://www.rfc-editor.org/info/rfc3779>.

   [RFC5652]  Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
              RFC 5652, DOI 10.17487/RFC5652, September 2009,
              <https://www.rfc-editor.org/info/rfc5652>.

   [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>.

   [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>.

   [RFC6489]  Huston, G., Michaelson, G., and S. Kent, "Certification
              Authority (CA) Key Rollover in the Resource Public Key
              Infrastructure (RPKI)", BCP 174, RFC 6489,
              DOI 10.17487/RFC6489, February 2012,
              <https://www.rfc-editor.org/info/rfc6489>.

Appendix A.  ASN.1 Module

       RPKIManifest { iso(1) member-body(2) us(840) rsadsi(113549)
                      pkcs(1) pkcs9(9) smime(16) mod(0) 60 }

   DEFINITIONS EXPLICIT TAGS ::=
      BEGIN

      -- EXPORTS ALL --

      IMPORTS

        CONTENT-TYPE
        FROM CryptographicMessageSyntax-2010 -- in RFC 6268
          { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1)
            pkcs-9(9) smime(16) modules(0) id-mod-cms-2009(58) } ;

      -- Manifest Content Type

      ct-rpkiManifest CONTENT-TYPE ::=
          { TYPE Manifest IDENTIFIED BY id-ct-rpkiManifest }

      id-smime OBJECT IDENTIFIER ::= { iso(1) member-body(2)
          us(840) rsadsi(113549) pkcs(1) pkcs9(9) 16 }

      id-ct OBJECT IDENTIFIER ::= { id-smime 1 }

      id-ct-rpkiManifest OBJECT IDENTIFIER ::= { id-ct 26 }

      Manifest ::= SEQUENCE {
         version        [0] INTEGER DEFAULT 0,
         manifestNumber     INTEGER (0..MAX),
         thisUpdate         GeneralizedTime,
         nextUpdate         GeneralizedTime,
         fileHashAlg        OBJECT IDENTIFIER,
         fileList           SEQUENCE SIZE (0..MAX) OF FileAndHash
         }

      FileAndHash ::= SEQUENCE {
         file  IA5String,
         hash  BIT STRING
         }

      END

Appendix B.  Changes since RFC 6486

   In 2019, it came to light that multiple RP implementations were in a
   vulnerable position, possibly due to perceived ambiguity in the
   original [RFC6486] specification.  This document attempts to clarify
   the innovative concept and application of RPKI manifests in light of
   real-world deployment experience in the global Internet routing
   system, to avoid future problematic cases.

   The following list summarizes the changes between RFC 6486 and this
   document:

   *  Forbidding "sequential-use" EE certificates and instead mandating
      "one-time-use" EE certificates.

   *  Clarifying that manifest EE certificates are to be issued with a
      validity period that coincides with the interval specified in the
      manifest eContent, which coincides with the CRL's thisUpdate and
      nextUpdate.

   *  Clarifying that the manifestNumber is monotonically incremented in
      steps of 1.

   *  Recommending that CA issuers include the applicable CRL's
      nextUpdate with the manifest's nextUpdate.

   *  Constraining the set of valid characters in FileAndHash file
      names.

   *  Clarifying that an RP unable to obtain the full set of files
      listed on a manifest is considered to be in a failure state, in
      which case cached data from a previous attempt should be used (if
      available).

   *  Clarifying the requirement for a current CRL to be present,
      listed, and verified.

   *  Removing the notion of "local policy".

Acknowledgements

   The authors would like to acknowledge the contributions from George
   Michaelson and Randy Bush in the preparation of the manifest
   specification.  Additionally, the authors would like to thank Mark
   Reynolds and Christopher Small for assistance in clarifying manifest
   validation and RP behavior.  The authors also wish to thank Tim
   Bruijnzeels, Job Snijders, Oleg Muravskiy, Sean Turner, Adianto
   Wibisono, Murray Kucherawy, Francesca Palombini, Roman Danyliw, Lars
   Eggert, Robert Wilton, and Benjamin Kaduk for their helpful review of
   this document.

Authors' Addresses

   Rob Austein
   Arrcus, Inc.
   Email: sra@hactrn.net


   Geoff Huston
   APNIC
   6 Cordelia St
   South Brisbane  QLD 4101
   Australia
   Email: gih@apnic.net


   Stephen Kent
   Independent
   Email: kent@alum.mit.edu


   Matt Lepinski
   New College Florida
   5800 Bay Shore Rd.
   Sarasota, FL 34243
   United States of America
   Email: mlepinski@ncf.edu