[smime] [Technical Errata Reported] RFC2634 (6562)

RFC Errata System <rfc-editor@rfc-editor.org> Wed, 28 April 2021 18:08 UTC

To: phoffman@imc.org, rdd@cert.org, kaduk@mit.edu, paul.hoffman@vpnc.org, blaker@gmail.com
From: RFC Errata System <rfc-editor@rfc-editor.org>
Cc: David.von.Oheimb@siemens.com, smime@ietf.org, rfc-editor@rfc-editor.org
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Message-Id: <20210428180743.7B3D3F407B3@rfc-editor.org>
Date: Wed, 28 Apr 2021 11:07:43 -0700
Archived-At: <https://mailarchive.ietf.org/arch/msg/smime/7_jJ7oiShtzuz-WGEWl6xPR6y8Q>
Subject: [smime] [Technical Errata Reported] RFC2634 (6562)
Precedence: list

The following errata report has been submitted for RFC2634,
"Enhanced Security Services for S/MIME".

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You may review the report below and at:
https://www.rfc-editor.org/errata/eid6562

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Type: Technical
Reported by: David von Oheimb <David.von.Oheimb@siemens.com>

Section: 5.4

Original Text
-------------
The first certificate identified in the sequence of certificate
identifiers MUST be the certificate used to verify the signature. The
encoding of the ESSCertID for this certificate SHOULD include the
issuerSerial field. If other constraints ensure that
issuerAndSerialNumber will be present in the SignerInfo, the
issuerSerial field MAY be omitted. The certificate identified is used
during the signature verification process. If the hash of the
certificate does not match the certificate used to verify the
signature, the signature MUST be considered invalid.

If more than one certificate is present in the sequence of
ESSCertIDs, the certificates after the first one limit the set of
authorization certificates that are used during signature validation.

Corrected Text
--------------
The sequence of certificate identifiers MUST contain at least one element.
The first certificate identified MUST be the certificate used to verify the signature.
The encoding of the ESSCertID for this certificate SHOULD include the
issuerSerial field. If other constraints ensure that
issuerAndSerialNumber will be present in the SignerInfo, the
issuerSerial field MAY be omitted. The certificate identified is used
during the signature verification process. If the hash of the
certificate does not match the certificate used to verify the
signature, the signature MUST be considered invalid.

If more than one certificate identifier is present in the sequence of ESSCertIDs,
all certificates referenced there MUST be part of the signature validation chain.

Notes
-----
Some aspects of the 'certs' field of a SigningCertificate attribute:

SigningCertificate ::= SEQUENCE {
certs SEQUENCE OF ESSCertID,
policies SEQUENCE OF PolicyInformation OPTIONAL
}

described in the sentences quoted above are very vague.
This lead to major confusion and wrong implementations.
As meanwhile has been clarified, they should be re-phrased;
see suggested new version above.

(One may further mandate/clarify that the certificate identifiers must be given in the same order
as they are expected in the validation chain, but I think this is not important because
the order should not play a critical role and will be determined by the validation chain anyway.)

Instructions:
-------------
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RFC2634 (draft-ietf-smime-ess-12)
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Title : Enhanced Security Services for S/MIME
Publication Date : June 1999
Author(s) : P. Hoffman, Ed.
Category : PROPOSED STANDARD
Source : S/MIME Mail Security
Area : Security
Stream : IETF
Verifying Party : IESG

[smime] [Technical Errata Reported] RFC2634 (6562) RFC Errata System
Re: [smime] [Technical Errata Reported] RFC2634 (… Russ Housley