Network Working GroupT. Roessler
Expires: November 13, 2009K. Lanz
 May 12, 2009

Additional XML Security Algorithm Identifiers

Status of this Memo

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This memo defines a number of additional Uniform Resource Identifiers (URIs) intended to identify cryptographic algorithms for use with the XML Digital Signature and Encryption Specifications. It complements RFC 4051 (Eastlake, D., “Additional XML Security Uniform Resource Identifiers (URIs),” April 2005.) [RFC4051].

1.  Introduction

XML Digital Signature and Encryption have been standardized by the W3C and by joint W3C/IETF work. They are currently under further revision by a W3C working group.

All of these specifications use URIs to identify algorithm and keying information types. This document provides URIs and descriptions for algorithms in which there is substantial interest, but which have not been included in either the main documents, or previous reference documents.

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 (Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” March 1997.) [RFC2119].

2.  Algorithms

Algorithms added in this document are given URIs that start with:

2.1.  Hash Algorithms

2.1.1.  Whirlpool


The Whirlpool algorithm [ISOIEC10118‑3] (tbd, tbd., “ISO/IEC 10118-3,” Y Z.) takes no explicit parameters. A Whirlpool digest is a 512 bit string. The content of the DigestValue element shall be the base64 [RFC2045] (tbd, tbd., “RFC 2045,” Y Z.) encoding of this string viewed as a 64 octet stream.

2.2.  Signature Algorithms

2.2.1.  RSA-Whirlpool


As in the definition of the RSA-SHA1 algorithm in [XMLDSIG] (tbd, tbd., “XML Signature Second Edition,” Y Z.), the designator "RSA" means the RSASSA-PKCS1-v1_5 algorithm as defined in PKCS2.1 (tbd, tbd., “PKCS 2.1,” Y Z.) [PKCS2.1]. When identified through the #rsa-whirlpool fragment identifier, Whirlpool is used as the hash algorithm instead. Use of the ASN.1 BER Whirlpool algorithm designator is implied.

@@ give that designator as an explicit octet sequence?

2.2.2.  ECDSA-RIPEMD160 and ECDSA-Whirlpool


The ECDSA algorithm takes no explicit parameters; the algorithm identifiers defined in this document describe the use of this algorithm with the Whirlpool and RIPEMD160 hash algorithms.

The output of the ECDSA algorithm consists of a pair of integers usually referred by the pair (r, s). The signature value consists of the base64 encoding of the concatenation of two octet-streams that respectively result from the octet-encoding of the values r and s in that order. Integer to octet-stream conversion must be done according to the I2OSP operation defined in the PKCS 2.1 (tbd, tbd., “PKCS 2.1,” Y Z.) [PKCS2.1] specification with the l parameter equal to the size of the output of the digest function in bytes (e.g. 32 for SHA-256).

@@ Not having looked at X9.62, I don't know whether we're underspecifying here. Anybody want to cross-check?

3. References

[RFC4051] Eastlake, D., “Additional XML Security Uniform Resource Identifiers (URIs),” RFC 4051, April 2005.
[RFC2119] Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” RFC 2119, March 1997.
[RFC2045] tbd, tbd., “RFC 2045,” Y Z.
[ISOIEC10118-3] tbd, tbd., “ISO/IEC 10118-3,” Y Z.
[XMLDSIG] tbd, tbd., “XML Signature Second Edition,” Y Z.
[PKCS2.1] tbd, tbd., “PKCS 2.1,” Y Z.

Authors' Addresses

  Thomas Roessler
  World Wide Web Consortium
  2004 Route des Lucioles
  Sophia Antipolis 06902
Phone:  +1.781.426.3109
  Konrad Lanz
  Institute for Applied Information Processing and Communications
  Inffeldgasse 16a
  Graz 8010
Phone:  +43 316 873 5547

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