Clarifying RPKI use of CMS SignerInfo
draft-michaelson-signerinfo-00

Abstract

RFC6485 section 2 mandated a single CMS OID sha256withRSAEncryption from RFC4055 for use in the CMS SignerInfo field. This draft updates RFC6485 and extends it to permit the correct CMS use which includes an option of rsaEncryption for the SignerInfo field.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on July 24, 2014.

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Table of Contents

• 1. Introduction
• 1.1. Requirements Language
• 2. Revised CMS SignerInfo
• 3. Acknowledgements
• 4. IANA Considerations
• 5. Security Considerations
• 6. References
• 6.1. Normative References
• 6.2. Informative References
• Authors' Addresses

1. Introduction

RFC 6485 [RFC6485] defines The Profile for Algorithms and Key Sizes for Use in the Resource Public Key Infrastructure (RPKI). In that document, Section 2 specifies a single signature algorithm (SHA-246) and a single CMS OID, sha256withRSAEncryption, to be used for the SignerInfo field of the CMS object.

A closer reading of the relevant RFCs RFC 4055 [RFC4055] and RFC 5754 [RFC5754] identified that the CMS SignerInfo field must support use of the rsaEncryption OID for full conformance with the CMS specifications, and the normative references in RFC 6485 inherit this requirement.

To ensure conformance with the CMS specifications, RFC 6485 is updated by this draft. All of RFC 6485 applies except for a change to the SignerInfo field.

1.1. Requirements Language

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 RFC 2119 [RFC2119].

2. Revised CMS SignerInfo

In RFC 6485, Section 2 the following sentence:

• The Object Identifier (OID) sha256withRSAEncryption from [RFC4055] MUST be used.

is replaced by:

• One of the Object Identifiers (OID) rsaEncryption or sha256WithRSAEncryption from [RFC4055] MUST be used. RPKI implementations MUST support rsaEncryption for the signatureAlgorithm field and SHOULD support sha256WithRSAEncryption.

3. Acknowledgements

This draft reflects a discussion between Rob Austein and Matt Lepinski on the SIDR Working group mailing list and a private communication between Rob Austein and Geoff Huston.

4. IANA Considerations

This memo includes no request to IANA.

5. Security Considerations

By conforming more closely to the CMS specifications, RPKI CMS objects are less likely to be rejected as non-conformant with the standards. No change is made to the cryptographic status of the CMS objects produced.

6. References

6.1. Normative References

6.2. Informative References

Authors' Addresses