Hello,

I have done my best to apply all the feedback gathered from the adoption
call, and I want to draw your attention to the latest draft, and its
primary remaining obstacles for discussion at ietf 120.

In my haste, I may have destroyed something essential. Apologies to my
co-authors, feel free to roast me at the mic line.

Be advised the github repo for the working group adopted draft is currently
here, PRs are welcome:

https://github.com/OR13/draft-ietf-jose-hpke-encrypt

As you can see from the document history -01 addresses several points of
feedback, and uses the terminology and guidance regarding algorithm names
provided by Ilari and others.

Major changes in this version:

- JWK is no longer used for encapsulated keys, but "encrypted_key" JWE
member and "ek" header parameter are.
- HPKE mode (base / auth / psk / psk_auth) is no longer included in
algorithm registrations.
- HPKE Setup info and aad are addressed in a single location for both
integrated and key encryption with hpke.
- "dir" approach has been replaced with "enc": <some registered aead>.
- "jwe aad" examples have been added.
- "psk_id" and "auth_kid" examples have been added.

I've implemented version -01, and the examples are produced from my
prototype.

Risk areas, and things which we would like to resolve ASAP.

### Fully specified HPKE algorithms

It would be nice to have confidence that the algorithm names will not
change.

For example where we currently see:

```
"alg": "HPKE-P256-SHA256-A128GCM",
"enc": "A128GCM",
```

We might see:

```
"alg": "HPKE-P256-SHA256",
"enc": "A128GCM",
```

Or whatever the working group decides counts as a "fully specified HPKE
algorithm".

```
"alg": "HPKE-P256-SHA256+A128KW", ?
```

### HPKE AAD vs JWE AAD

I think the current approach is better than computing some custom KDF info
from apu / apv... But is setting the following as HPKE AAD enough?

hpke-info = empty
hpke-aad = encode-protected-header . aad (when JWE aad is available)

Where encoded protected header is either the protected header for
hpke jwe integrated encryption, or the protected header used in content
encryption, for which the content encryption key is being encrypted?

### Lossy conversions

It's possible to express things in JSON Serialization that can't be
expressed in Compact serialization.
I tried to make this explicit, but we could decide to simply forbid
conversions from JSON to Compact that lose information, or that would move
things around "ek" to "encrypted_key".


Thanks for all the feedback during the adoption call.

Regards,

OS

-- 


ORIE STEELE
Chief Technology Officer
www.transmute.industries

<https://transmute.industries>
_______________________________________________
jose mailing list -- [email protected]
To unsubscribe send an email to [email protected]

Reply via email to