Subject: Re: [PATCH] netdevsim: psp: reset spi on key rotation and check for exhaustion on alloc

From: Willem de Bruijn <[email-masked]>
Date: Fri, 15 May 2026 16:57:42 -0400

Daniel Zahka wrote:
> The PSP spec states that the lower 31b of the SPI need to be
> non-zero. Though not in the spec, I think it is reasonable to reset
> the lower 31b of the spi space after a key rotation, and to also
> decline to generate session keys when the lower 31b saturate.

This could be stated more clearly in the spec indeed. At a minimum as
a suggestion ("should"). 

It does imply the second: "The SPI field is 31 bits long (since 1 bit
is taken as the master key indicator), so the master keys must be
rotated before the key’s SPI space is exhausted."

> 
> Assisted-by: Claude:claude-opus-4.7
> Signed-off-by: Daniel Zahka <[email-masked]>

[PATCH net-next]

Reviewed-by: Willem de Bruijn <[email-masked]>