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Re: [kitten] Question about AES mode in Kerberos

Luke Howard Bentata <lukeh@padl.com> Tue, 17 January 2023 22:56 UTC

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From: Luke Howard Bentata <lukeh@padl.com>
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Date: Wed, 18 Jan 2023 09:56:24 +1100
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Subject: Re: [kitten] Question about AES mode in Kerberos
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> While NFS "moves to TLS" that's only for auth_sys mode. Anybody that
> cares about security, uses ACLs for authorization, will require
> Kerberos authentication. One of the reasons NFS is moving towards TLS
> is the hope of better performance (it seems that NIC's have incentives
> to implement onboard TLS or IPSec protocols but not Kerberos GSS).
> Another reason unfortunately is because too many folks just want
> auth_sys but over a secure channel.

You could do Kerberos over TLS (with channel binding).

But yes, perhaps a way of using a Kerberos session key as a TLS PSK would better allow for hardware offload.

> Wouldn't it be wonderful that instead of needing to layer a GSS
> authentication on top of TLS (as GSS in itself can provide
> authentication and privacy) we could make GSS be a competitor to TLS
> by having the same ciphers and having same NIC hardware offload
> support (but I realize that the latter is not something a spec can
> fix)…


Well, having a spec and multiple implementations can be a good start. Had I put some energy into progressing the spec when I first wrote it in 2015, perhaps we would be in a different position now.

— Luke

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