Paul, the parameters sections are still wrong. As I noted
in my previous message, all the digests and rsaEncryption
take a NULL parameter. The parameter is NOT optional.
For some value of optional. We're still a bit schizophrenic in CMS about
must and should language, since CMS is not really a protocol. Russ chose
not to refer to RFC 2119 because of this, I think. So when we say "optional
but implementations should emit a NULL parameter", that's about as strong
as "MUST emit a NULL parameter but should accept with no parameters".
Unless I hear differently, I'll go with Eric's stronger wording.
CMS implementations must include Static Diffie-Hellman with tripleDES. CMS
implementations may include RSA. CMS implementations may include
Static Diffie-Hellman with RC2.
What about DH with DES?
No one had asked about this. If folks want one specified, please give an
OID and any other information needed. Out of curiousity, what applications
do we expect to use DH-DES that aren't using one of the other three?
id-smime-cms-dh-with-tripleDES ::= { TBD }
We're defining our own OID here, but I don't like this 'NULL or
omit' stuff. We should settle on one and stick to it.
Must NULL it is.
For the effective-key-bits of 40, 64, and 128, the rc2ParameterVersion
values are 160, 120, 58 respectively. It is very important to note that
these values are not simply the RC2 keylength. Also note that the value 160
must be encoded as two octets (00 A0), because encoding as one octet (A0)
is a negative number in ASN.1.
What's the input key length?
That's one for the implementors. Blake, et. al.?
ContentEncryptionAlgorithmIdentifier protocol field. Triple-DES may be an
exception here; the same identifier is used for both 2-key and 3-key Triple
DES.
No it isn't. DES-EDE3 means 3 key 3DES.
Hmmm. Russ wrote that wording on the list many weeks ago, and no one objected.
DES-EDE3-CBC OBJECT IDENTIFIER ::= {iso(1) member-body(2) us(840)
rsadsi(113549) encryptionAlgorithm(3) 7}
The AlgorithmIdentifier parameter field is required and has the structure:
CBCParameter :: IV
IV ::= OCTET STRING -- 8 octets.
Surely there is a SECSIC OID?
Surely, but this is the one that we've been using in S/MIME. Changing it
now would break backwards compatibility. I don't think we need to take
purity of OIDs that far.
--Paul Hoffman, Director
--Internet Mail Consortium