File: png-dSIG-OID.txt This document is a companion to the recently-approved dSIG chunk. It was approved by vote of the PNG Development Group on October 5, 2008. There is a need for countersigners to add comments. A logical place to put such comments would have been signed-comment OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9) 7 } which could have been described under paragraph 11 of RFC-3852 [1], but there is no definition of a signedComment type there. Therefore we define a signedComment OID here. For completeness, we also define an unsignedComment OID. The IANA "Private Enterprise Number (PEN)" 1.3.6.1.4.1.31170 was assigned to the PNG Development Group, and the specification of OIDs in a subtree under that has been delegated to the PNG Development Group (see [2]). For dSIG purposes, the following new subtree is defined: 1.3.6.1.4.1.31170: PNG 1.3.6.1.4.1.31170.1: dSIG 1.3.6.1.4.1.31170.1.1: signeddSIGdata 1.3.6.1.4.1.31170.1.1.1: signedComment 1.3.6.1.4.1.31170.1.2: unsigneddSIGdata 1.3.6.1.4.1.31170.1.2.1: unsignedComment A future definition might add: 1.3.6.1.4.1.31170.2: another PNG category The new OIDs are described as follows: signedComment OBJECT IDENTIFIER ::= { iso(1) org(3) dod(6) internet(1) private(4) enterprise(1) PNG(31170) dSIG(1) signeddSIGdata(1) signedComment(1) } unsignedComment OBJECT IDENTIFIER ::= { iso(1) org(3) dod(6) internet(1) private(4) enterprise(1) PNG(31170) dSIG(1) unsigneddSIGdata(2) unsignedComment(1) } Both types of comment have data type "PrintableString" as defined in the ASN.1 Basic Encoding Rules (see [3]). In the future, any other chunks needing to specify ASN.1 OIDs would have their own subtrees under the PNG PEN, e.g., 1.3.6.1.4.1.31170.2 for a second chunk type. References: [1] RFC-3852, R. Housley, Vigil Security, "Cryptographic Message Syntax (CMS)", available at http://www.ietf.org/rfc/rfc3852.txt [2] IANA, "PRIVATE ENTERPRISE NUMBERS", available at http://www.iana.org/assignments/enterprise-numbers [3] ITU-T Rec. X.680 (07/2002)Information technology -- Abstract Syntax Notation One (ASN.1): Specification of basic notation, available at http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf