--- 1/draft-ietf-ipsecme-chacha20-poly1305-00.txt 2015-03-31 04:17:01.771124876 -0700 +++ 2/draft-ietf-ipsecme-chacha20-poly1305-01.txt 2015-03-31 04:17:01.787125256 -0700 @@ -1,18 +1,18 @@ Network Working Group Y. Nir Internet-Draft Check Point -Intended status: Standards Track March 30, 2015 -Expires: October 1, 2015 +Intended status: Standards Track March 31, 2015 +Expires: October 2, 2015 - ChaCha20, Poly1305 and their use in IPsec - draft-ietf-ipsecme-chacha20-poly1305-00 + ChaCha20, Poly1305 and their use in IKE & IPsec + draft-ietf-ipsecme-chacha20-poly1305-01 Abstract This document describes the use of the ChaCha20 stream cipher along with the Poly1305 authenticator, combined into an AEAD algorithm for IPsec. Status of This Memo This Internet-Draft is submitted in full conformance with the @@ -21,42 +21,42 @@ 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 http://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 October 1, 2015. + This Internet-Draft will expire on October 2, 2015. Copyright Notice Copyright (c) 2015 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 (http://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 1.1. Conventions Used in This Document . . . . . . . . . . . . 2 - 2. ESP_ChaCha20-Poly1305 for ESP . . . . . . . . . . . . . . . . 3 + 2. ChaCha20 & Poly1305 for ESP . . . . . . . . . . . . . . . . . 3 2.1. AAD Construction . . . . . . . . . . . . . . . . . . . . 4 3. Use in IKEv2 . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 7.1. Normative References . . . . . . . . . . . . . . . . . . 5 7.2. Informative References . . . . . . . . . . . . . . . . . 5 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6 @@ -71,35 +71,36 @@ only the best choice, but the only choice. The problem is that if future advances in cryptanalysis reveal a weakness in AES, VPN users will be in an unenviable position. With the only other widely supported cipher being the much slower 3DES, it is not feasible to re-configure IPsec installations to use 3DES. [standby-cipher] describes this issue and the need for a standby cipher in greater detail. This document proposes the ChaCha20 stream cipher as such a standby - cipher in an AEAD construction with the Poly1305 authenticator for - use with the Encapsulated Security Protocol (ESP - [RFC4303]) and the - Internet Key Exchange Protocol (IKEv2 - [RFC7296]). The algorithms - are described in a separate document ([chacha_poly]). This document - only describes the IPsec-specific things. + cipher in an Authenticated Encryption with Associated Data (AEAD) + construction with the Poly1305 authenticator for use with the + Encapsulated Security Protocol (ESP - [RFC4303]) and the Internet Key + Exchange Protocol (IKEv2 - [RFC7296]). The algorithms are described + in a separate document ([chacha_poly]). This document only describes + the IPsec-specific things. 1.1. Conventions Used in This Document 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]. -2. ESP_ChaCha20-Poly1305 for ESP +2. ChaCha20 & Poly1305 for ESP - ESP_ChaCha20-Poly1305 is a combined mode algorithm, or AEAD. The + AEAD_CHACHA20_POLY1305 is a combined mode algorithm, or AEAD. The construction follows the AEAD construction in section 2.7 of [chacha_poly]: o The IV is 64-bit, and is used as part of the nonce. TBD: do we want to skip the IV altogether and just use the packet counter? o A 32-bit sender ID is prepended to the 64-bit IV to form the 96-bit nonce. For regular IPsec, this is set to all zeros. IPsec extensions that allow multiple senders, such as GDOI ([RFC6407]) or [RFC6054] may set this to different values. o The encryption key is 256-bit. @@ -183,21 +184,21 @@ Another issue with implementing these algorithms is avoiding side channels. This is trivial for ChaCha20, but requires some care for Poly1305. Considerations for implementations of these algorithms are in the [chacha_poly] document. 5. IANA Considerations IANA is requested to assign one value from the IKEv2 "Transform Type 1 - Encryption Algorithm Transform IDs" registry, with name - ESP_ChaCha20-Poly1305, and this document as reference. + ENCR_ChaCha20_Poly1305, and this document as reference. 6. Acknowledgements All of the algorithms in this document were designed by D. J. Bernstein. The AEAD construction was designed by Adam Langley. The author would also like to thank Adam for helpful comments, as well as Yaron Sheffer for telling me to write the algorithms draft. 7. References