Comments to CMS-01

Russ (and friends),

Thank you for incorporating my previous comments into the November 97
Cryptographic Message Syntax (CMS-01).  I have a few comments to CMS-01:

1) Sec 3, last para: This paragraph discusses "external signatures".  This
concept adds significant complexity to the CMS security services.  Is it
really needed?

2) Sec 3, last para:  If it is decided that the CMS spec still needs to
support "external signatures", then the following issue needs to be
clarified.   Is it true that the signatureValue in a SignedData object in
which the content is absent is calculated exactly as with a SignedData in
which the content is present?  If so, then please add a sentence to the last
para of Sec 3 stating that fact. 

3) Sec 3, last para: If it is decided that the CMS spec still needs to
support "external signatures", then please add the following sentence:  "In
this case, the content type within the ContentInfo must be id-data and the
content field of the ContentInfo must be omitted (i.e. absent)."

4) Sec 5.2: This references PKCS #9.  The WG still needs to duplicate the
PKCS #9 contents in an IETF-controlled document.  The CMS should then be
changed to reference the IETF-controlled document.

5) Sec 6, Intro, Step 3:  Do you think that it is worthwhile to mention in
the CMS spec that a sending agent should include a copy of the
content-encryption key that is protected using the originator's key material
so that the originator can always decrypt the message?

6) Sec 7.1: This section states: "The definition of
CertificateRevocationList is imported from X.509.
      CertificateRevocationLists ::= SET OF CertificateRevocationList".

However, the 97 X.509 Recommendation includes the following definition of
CertificateRevocationList:

"certificateRevocationList      ATTRIBUTE       ::=     {
                                WITH SYNTAX     CertificateList
                                EQUALITY MATCHING RULE certificateListExactMatch
                                ID                              
id-at-certificateRevocationList }

CertificateList ::= SIGNED { SEQUENCE {
  version       Version OPTIONAL,
                -- if present, version must be v2
  signature     AlgorithmIdentifier,
  issuer        Name,
  thisUpdate    Time,
  nextUpdate    Time OPTIONAL,
  revokedCertificates   SEQUENCE OF SEQUENCE {
                                userCertificate         CertificateSerialNumber,
                                revocationDate          Time,
                                crlEntryExtensions      Extensions OPTIONAL } 
OPTIONAL,
  crlExtensions [0]  Extensions OPTIONAL }}"

I believe that the intent was for the CMS SignedData and OriginatorInfo
syntaxes to include a SET OF CertificateList rather than SET OF
CertificateRevocationList (which would be a SET of attributes containing
CertificateLists).

In summary, please change sec 7.1 to state: "The definition of
CertificateList is imported from X.509.
      CertificateRevocationLists ::= SET OF CertificateList".


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John Pawling   
jsp(_at_)jgvandyke(_dot_)com                             
J.G. Van Dyke & Associates, Inc.           
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