| Network Working Group | T. Bruijnzeels |
| Internet-Draft | RIPE NCC |
| Intended status: Standards Track | C. Martinez |
| Expires: December 31, 2017 | LACNIC |
| June 29, 2017 |
RPKI signed object for TAL
draft-tbruijnzeels-sidrops-signed-tal-00
Trust Anchor Locators (TALs) [RFC7730] are used by Relying Parties in the RPKI to locate and validate Trust Anchor certificates used in RPKI validation. This documents defines an RPKI signed object [RFC6488] for a Trust Anchor Locator (TAL) that can be published by Trust Anchor to communicate a new TAL to already deployed Relying Parties. The two primary use cases for this are that 1) a Trust Anchor may wish to change the locations where its TA certificate may be found, and 2) a Trust Anchor may wish to perform a planned migration to a new key. Note that unplanned key rolls are considered out of scope for this document.
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The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].
Trust Anchor Locator (TAL) files [RFC7730] are used in the Resource Public Key Infrastructure (RPKI) to help Relying Parties locate and verify a trust anchor certificate. A TAL file consists of:
The TAL can be distributed out-of-band to Relying Parties (RP), and it allows the RP to retrieve the most recent version of the Trust Anchor (TA) certificate from the cited location, and verify that public key of this certificate matches the TAL. This is useful as it allows selected data in the trust anchor to change, without needing to effect redistribution of the trust anchor per se. In particular the Internet Number Resources (INRs) extension [RFC3779] and the publication points defined in the Subject Information Access [RFC6487] may be updated this way.
The assumption is that both the URIs and key of the TA certificate remain stable. However, an organisation operating a TA may wish to change either of these properties, because of a need to:
In this document we describe a method for TA operators to publish a an updated TAL in a secure a well-defined fashion, so that RPs can be alerted to these changes.
A signed TAL 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.
This document requests an OID for signed-Tal as follows:
signed-Tal OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840)
rsadsi(113549) pkcs(1) pkcs9(9) 16 id-smime (1) TBD }
This OID MUST appear both within the eContentType in the encapContentInfo object as well as the content-type signed attribute in the signerInfo object (see [RFC6488]).
The content of a Signed TAL is ASN.1 encoded using the Distinguished Encoding Rules (DER) [X.690], and is defined as follows:
SignedTalContent ::= IA5String
The "SignedTalContent" contains the content of the new TAL encoded in Base64 [RFC4648].
Before a Relying Party can use a Signed TAL, the relying party MUST first validate the Signed TAL. To validate a Signed TAL, the relying party MUST perform all the validation checks specified in [RFC6488] as well as the following additional specific validation step.
If the above procedure indicates that the manifest is invalid, then the Signed TAL MUST be discarded and treated as though no Signed TAL were present.
A TA MAY choose to generate a single Singed TAL object to publish in its TA certificate publication point(s) in the RPKI. The TA MUST perform the following steps to generate the Signed TAL:
A TA MAY publish a single Signed TAL object directly under its TA certificate publication point(s) in the RPKI. The object base filename SHOULD use a similar strategy as the base filename that is used to the determine the CRL and Manifest filenames for this TA certificate, and the extension part of the filename MUST be ".tal".
A Signed TAL MAY be used to communicate a planned key roll for the TA.
Prior to publishing the Signed TAL for the new key the TA MUST perform the following steps:
After these steps are performed a new Signed TAL MUST be generated as described in Section 4, and published as described in Section 5.
The staging period is initiated by the initial publication of a Signed TAL for the new key and must last at least 24 HOURS.
During the staging period the TA MUST continue to operate both the old and the new TA key.
The TA MAY preserve a Signed TAL for the old key after the staging period as a hint for RPs that missed the key roll. The following process can be used to achieve this:
The TA MAY retire and delete its old key after the staging period is over.
A signed TAL MAY be used to communicate an addition or removal of one or more publication locations where the TA certificate can be found.
When adding a publication point for a TA certificate, the TA MUST publish the certificate in the new location(s) prior to publication of the Signed TAL.
When removing a publication point for TA certificate, the TA SHOULD observe a staging period of at least 24 Hours. The staging period is initiated by the publication of an updated Signed TAL where the publication point has been removed. During the staging period the TA SHOULD keep the old publication point up to date and available.
The TA MUST withdraw the Signed TAL after the chosen staging period, of at least 24 hours, is over.
When an RP discovers a new valid TAL signed under a trust anchor, it SHOULD substitute the current TAL immediately.
RP software MAY start using the new TAL thus found automatically without operator intervention, but it is RECOMMENDED that the software informs the operator of this event, and keeps a back-up of the old TAL.
Furthermore, it is RECOMMENDED that the RP software informs the operator whether the new TAL represents a key roll, or a change in URIs only.
IANA is to add the following to the "RPKI Signed Objects" registry:
Decimal Description References
TBD signed-Tal [section 3.1]
IANA is to add an item for the Signed TAL file extension to the "RPKI Repository Name Scheme" created by [RFC6481] as follows:
Extension RPKI Object Reference
-------------------------------------------------------
.tal Signed TAL [this document]
TBD
TBD