RFC 3537 (rfc3537) - Page 1 of 9
Wrapping a Hashed Message Authentication Code (HMAC) key with a Triple-Data Encryption Standard (DES) Key or an Advanced Encryption Standard (AES) Key
Alternative Format: Original Text Document
Network Working Group J. Schaad
Request for Comments: 3537 Soaring Hawk Consulting
Category: Standards Track R. Housley
Vigil Security
May 2003
Wrapping a Hashed Message Authentication Code (HMAC) key
with a Triple-Data Encryption Standard (DES) Key
or an Advanced Encryption Standard (AES) Key
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
This document defines two methods for wrapping an HMAC (Hashed
Message Authentication Code) key. The first method defined uses a
Triple DES (Data Encryption Standard) key to encrypt the HMAC key.
The second method defined uses an AES (Advanced Encryption Standard)
key to encrypt the HMAC key. One place that such an algorithm is
used is for the Authenticated Data type in CMS (Cryptographic Message
Syntax).
1. Introduction
Standard methods exist for encrypting a Triple-DES (3DES) content-
encryption key (CEK) with a 3DES key-encryption key (KEK) [3DES-
WRAP], and for encrypting an AES CEK with an AES KEK [AES-WRAP].
Triple-DES key wrap imposes parity restrictions, and in both
instances there are restrictions on the size of the key being wrapped
that make the encryption of HMAC [HMAC] keying material difficult.
This document specifies a mechanism for the encryption of an HMAC key
of arbitrary length by a 3DES KEK or an AES KEK.
Schaad & Housley Standards Track