From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc5581.txt | 171 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 171 insertions(+) create mode 100644 doc/rfc/rfc5581.txt (limited to 'doc/rfc/rfc5581.txt') diff --git a/doc/rfc/rfc5581.txt b/doc/rfc/rfc5581.txt new file mode 100644 index 0000000..eaa0e69 --- /dev/null +++ b/doc/rfc/rfc5581.txt @@ -0,0 +1,171 @@ + + + + + + +Network Working Group D. Shaw +Request for Comments: 5581 June 2009 +Updates: 4880 +Category: Informational + + + The Camellia Cipher in OpenPGP + +Status of This Memo + + This memo provides information for the Internet community. It does + not specify an Internet standard of any kind. Distribution of this + memo is unlimited. + +Copyright Notice + + Copyright (c) 2009 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 in effect on the date of + publication of this document (http://trustee.ietf.org/license-info). + Please review these documents carefully, as they describe your rights + and restrictions with respect to this document. + +Abstract + + This document presents the necessary information to use the Camellia + symmetric block cipher in the OpenPGP protocol. + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 + 2. Requirements Notation . . . . . . . . . . . . . . . . . . . . . 2 + 3. Camellia . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 + 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 2 + 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 3 + 6. Normative References . . . . . . . . . . . . . . . . . . . . . 3 + + + + + + + + + + + + + +Shaw Informational [Page 1] + +RFC 5581 The Camellia Cipher in OpenPGP June 2009 + + +1. Introduction + + The OpenPGP protocol [RFC4880] can support many different symmetric + ciphers. This document presents the necessary information to use the + Camellia [RFC3713] symmetric cipher in the OpenPGP protocol. + +2. Requirements Notation + + 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]. + +3. Camellia + + Camellia is specified in [RFC3713]. It is a 128-bit symmetric block + cipher (as are AES and Twofish in OpenPGP) that supports 128-bit, + 192-bit, and 256-bit keys. This document defines the use of Camellia + in OpenPGP. + + +---------------------+----------------------------------------+ + | Camellia Key Length | OpenPGP Symmetric-Key Algorithm Number | + +---------------------+----------------------------------------+ + | 128 | 11 | + | 192 | 12 | + | 256 | 13 | + +---------------------+----------------------------------------+ + + OpenPGP applications MAY implement Camellia. If implemented, + Camellia may be used in any place in OpenPGP where a symmetric cipher + is usable, and it is subject to the same usage requirements (such as + its presence in the Preferred Symmetric Algorithms signature + subpacket) as the other symmetric ciphers in OpenPGP. + + While the OpenPGP algorithm preferences system prevents + interoperability problems with public key encrypted messages, if + Camellia (or any other optional cipher) is used for encrypting + private keys, there could be interoperability problems when migrating + a private key from one system to another. A similar issue can arise + when using an optional cipher for symmetrically encrypted messages, + as this OpenPGP message type does not use the algorithm preferences + system. Those using optional ciphers in this manner should take care + they are using a cipher that their intended recipient can decrypt. + +4. Security Considerations + + At publication time, there are no known weak keys for Camellia, and + the Camellia algorithm is believed to be strong. However, as with + any technology involving cryptography, implementers should check the + + + +Shaw Informational [Page 2] + +RFC 5581 The Camellia Cipher in OpenPGP June 2009 + + + current literature, as well as the Camellia home page at + http://info.isl.ntt.co.jp/camellia/ to determine if Camellia has been + found to be vulnerable to attack. + +5. IANA Considerations + + IANA assigned three algorithm numbers from the registry of OpenPGP + Symmetric-Key Algorithms that was created by [RFC4880]. + +6. Normative References + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [RFC3713] Matsui, M., Nakajima, J., and S. Moriai, "A Description of + the Camellia Encryption Algorithm", RFC 3713, April 2004. + + [RFC4880] Callas, J., Donnerhacke, L., Finney, H., Shaw, D., and R. + Thayer, "OpenPGP Message Format", RFC 4880, November 2007. + +Author's Address + + David Shaw + + EMail: dshaw@jabberwocky.com + + + + + + + + + + + + + + + + + + + + + + + + + + +Shaw Informational [Page 3] + -- cgit v1.2.3