ietf-smime
[Top] [All Lists]

Re: [smime] Message takeover attacks against S/MIME

2016-03-28 08:10:42
If the patient is on the table, then all of these look like items we’d need to 
address.

spt

On Mar 26, 2016, at 09:57, Wei Chuang <weihaw(_at_)google(_dot_)com> wrote:

Some more work item suggestions (I'm posting on behalf of someone who wishes 
to avoid the rough and tumble of discussion on the mailing list though reads 
it):
* Making ECC an official part of S/MIME, RFC5753 is only informational. 
* Authenticated encryption. 
* A better mechanism than sign-encrypt-sign to get both authentication and 
confidentiality (or at least a non-strippable way of doing it)
* Dropping obsolete ciphers and hashes from the spec: drop SHA-1, MD5, etc.
* A modernized RFC 4134 (practical examples of S/MIME messages, it could 
avoid the fiasco of 3rd party forgetting ASN-1 tags in their messages).

-Wei


On Sun, Mar 13, 2016 at 9:38 AM, Wei Chuang <weihaw(_at_)google(_dot_)com> 
wrote:
Some interesting usability consideration were raised on the PKIX list by 
Martin Rex in the thread "another attempt to canonicalize local parts" that 
could be addressed by a rechartered WG.  He points out problems with
- Incompletely specified cert chains preventing signature verification i.e. 
missing CA certs and no ability to fetch them.  Fully specifying the chains 
would resolve this.
- Reverifying old "archived" emails on his MUA not possible as the certs have 
expired.  Fixing a verification time on delivery or other scheme is desirable.

-Wei

On Thu, Mar 10, 2016 at 11:12 AM, Wei Chuang <weihaw(_at_)google(_dot_)com> 
wrote:


On Mon, Mar 7, 2016 at 10:58 PM, Russ Housley 
<housley(_at_)vigilsec(_dot_)com> wrote:
I am hearing interest in these topics (a combination of things on this list 
and side conversations).

(1) Specify the way to use authenticated encryption in S/MIME.  Note that it 
is already done for CMS.

(2) Specify conventions for AES-CCM, AES-GCM, and ChaCha20 with Poly1305 
authenticated encryption algorithms.

(3) Specify conventions for using Curve25519 and Curve448 for key agreement.

(4) Specify conventions for using the CFRG chosen curves for elliptic curve 
digital signature.

(5) Specify a way to use PGP public keys in addition to PKIX certificates.

Anything else?

While I'm afraid of scope creep as resolving the above would be very useful, 
could also mail header integrity and privacy be considered?  Perhaps the WG 
scope be split into near and long term work to help prioritize.  The above 
five items be categorize as near term and the mail header work considered 
longer term?

-Wei 

(PS yes there is RFC7508 which is experimental, and does not keep private the 
sender and recipient.  Still it is an improvement...)
 

Is this enough to re-charter the S/MIME WG?

Russ
_______________________________________________
smime mailing list
smime(_at_)ietf(_dot_)org
https://www.ietf.org/mailman/listinfo/smime



_______________________________________________
smime mailing list
smime(_at_)ietf(_dot_)org
https://www.ietf.org/mailman/listinfo/smime

_______________________________________________
smime mailing list
smime(_at_)ietf(_dot_)org
https://www.ietf.org/mailman/listinfo/smime

<Prev in Thread] Current Thread [Next in Thread>