Jim: I was thinking of the first case, but it would be good to support both.
Russ > On Jan 22, 2019, at 6:33 PM, Jim Schaad <[email protected]> wrote: > > Jim, > > Ok lets try this again, I don't think that you got the gist of my question. > (I have been told recently that I probably need to be more verbose in > describing my questions.) > > What I understand you want to do is to build a structure that looks > something like this: > > EncryptedMessage : { > Protected Headers, > Unprotected Headers, > AES-KeyWrap-Pad( PKCS #8 ), > Recipient: [ { > Protected Headers, > Unprotected Headers, > RSA-OAEP( AES-KeyWrap-Pad encryption key ) > }] > } > > In this case the key wrap is being done as a content encryption key even if > what it is encrypting a content which contains a private key. > > > The other case that I was talking about would be something like the > following: > > EncryptedMessage :{ > Protected Headers, > Unprotected Headers, > AES-GCM-128( some content ), > Recipient: [ { > Protected Headers, > Unprotected Headers, > ECDH ( CEK ), > Recipient: [{ > Protected Headers, > Unprotected Headers, > AES-KeyWrap-Pad( PKCS#8 w/ private ECDH key ) > }]}]} > > In this case one would both be transporting the private key - encrypted with > AES-KeyWrap and a pre-shared secret (or perhaps ECDH and AES-KeyWrap-Pad) > and that transported key is then being used to do an ECDH operation which is > then used to decrypt some content. > > In this case one is in essence transporting two different sets of encrypted > material: the "some content" information and the private key. > > Jim > > >> -----Original Message----- >> From: Russ Housley <[email protected]> >> Sent: Tuesday, January 22, 2019 3:21 PM >> To: Jim Schaad <[email protected]> >> Cc: cose <[email protected]> >> Subject: Re: [COSE] Adding AES Key Wrap with Padding >> >> Jim: >> >> PKCS#8 is a key that need to be wrapped. >> >> I want to be able to use if for any keying material, including an HMAC > key. >> >> Russ >> >> >>> On Jan 22, 2019, at 6:10 PM, Jim Schaad <[email protected]> wrote: >>> >>> Russ, >>> >>> That is indeed an interesting use case. Does this mean that you are >>> really more interested in using this as a content encryption algorithm >>> rather than a key encryption algorithm? I have doubts for this use >>> case that you are looking to wrap key and are looking to wrap content. >>> This is different than a use case where one wishes to use an HMAC >>> algorithm with a key which is not a multiple of 8 octets. >>> >>> Jim >>> >>> >>>> -----Original Message----- >>>> From: Russ Housley <[email protected]> >>>> Sent: Tuesday, January 22, 2019 2:36 PM >>>> To: Jim Schaad <[email protected]> >>>> Cc: cose <[email protected]> >>>> Subject: Re: [COSE] Adding AES Key Wrap with Padding >>>> >>>> Jim: >>>> >>>> The use case is wrapping PKCS#8 objects, which are not necessarily a >>> multiple >>>> of 8 octets. >>>> >>>> Russ >>>> >>>> >>>>> On Jan 22, 2019, at 5:09 PM, Jim Schaad <[email protected]> > wrote: >>>>> >>>>> Russ, >>>>> >>>>> I will ask the same question that I asked the last time that >>>>> somebody requested that we support the AES Key Wrap with Padding >> Algorithm. >>>>> What is the use case that you have for this algorithm. This makes a >>>>> difference in terms of how things are going to be used and what >>>>> other things might need to be specified for this. I have to admit >>>>> that I would really prefer to get an AEAD version of this algorithm >>>>> if we are going to add something but that I probably not possible. >>>>> >>>>> Jim >>>>> >>>>> >>>>> _______________________________________________ >>>>> COSE mailing list >>>>> [email protected] >>>>> https://www.ietf.org/mailman/listinfo/cose >>> > _______________________________________________ COSE mailing list [email protected] https://www.ietf.org/mailman/listinfo/cose
