Looking at draft-ietf-lamps-5480-ku-clarifications-01, these points occur to me: 1. Introduction This document corrects this omission, by updating Section 3 of [RFC5480] to make it clear that neither keyEncipherment nor the dataEncipherment key usage bits are set for key agreement algorithms. I think it would be more accurate to say something like "neither ... are set in certificates that specify key agreement algorithms" -- usage bits are logically a component of a certificate rather than a feature of an algorithm. But it's unclear to me whether id-ecPublicKey is only used in key agreement certificates. RFC 5480 states that if the cert uses id-ecDH or id-ecMQV and provides keyUsage, then keyAgreement must be set. So it's clear that certs with id-ecDH or id-ecMQV are key agreement certs. But RFC 5480 says that if the cert lists id-ecPublicKey, then keyAgreement is optional. That suggests to me that some certs can use id-ecPublicKey without being key agreement certs. In turn, section 1 of this I-D suggests the I-D is not intended to apply to those certs, but section 3 seems to apply to them anyway. To try to distill it to one sentence: Can id-ecPublicKey appear in certs that are not for key agreement, and if so, are keyEncipherment and dataEncipherment allowed in the keyUsage of those certs? 3. Updates to Section 3 If the keyUsage extension is present in a certificate that indicates in SubjectPublicKeyInfo, then following values MUST NOT be present: ---^ Is "id-ecPublicKey" missing here? If the keyUsage extension is present in a certificate that indicates id-ecDH or id-ecMQV in SubjectPublicKeyInfo, then the following values also MUST NOT be present: Is it a fact that all certificates with these three algorithms are certificates for key agreement? If so, it would be nice to state that either in section 3 or section 1, to show how section 3 is connected with "for key agreement algorithms" in section 1. Otherwise, the connection between the two requires information that is stated elsewhere. Dale -- last-call mailing list last-call@xxxxxxxx https://www.ietf.org/mailman/listinfo/last-call
