Re: [RFC PATCH 2/8] crypto/krb5: Provide Kerberos 5 crypto through AEAD API

Jeffrey E Altman
2025-01-10T18:30:22Z

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On 1/10/2025 5:02 AM, Herbert Xu wrote:
> So does your use-case support both standard AEAD algorithms such
> as GCM as well as these legacy algorithms?

RXGK is described by
https://datatracker.ietf.org/doc/draft-wilkinson-afs3-rxgk/.

Any RFC3961 ("Encryption and Checksum Specifications for Kerberos 5")
framework encryption algorithm can be used with it.

There have been proposals to add AEAD encryption types to RFC3961. For
example, Luke Howard proposed

https://datatracker.ietf.org/doc/draft-howard-krb-aead/

The Security Considerations section describes the reasons that MIT's
Kerberos team is reluctant to add AEAD algorithms to RFC3961. The
primary one being that AEAD algorithms are not safe for all of the
existing RFC3961 use cases and there is no means of ensuring that AEAD
encryption types would not be misused.

Requests for the addition of AEAD to RFC3961 have come from both the
NFSv4 community and those implementing RXGK. Alas, there has been no
forward progress since the publication of Luke's draft.

Jeffrey Altman

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