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Date: Tue, 4 Feb 2025 06:23:34 +0100
From: Christoph Hellwig <hch@lst.de>
To: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>, Hannes Reinecke <hare@kernel.org>,
	Keith Busch <kbusch@kernel.org>, Sagi Grimberg <sagi@grimberg.me>,
	linux-nvme@lists.infradead.org
Subject: Re: [PATCH 04/10] nvme: add nvme_auth_derive_tls_psk()
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On Mon, Feb 03, 2025 at 02:37:59PM +0100, Hannes Reinecke wrote:
> On 1/28/25 09:58, Christoph Hellwig wrote:
>>> +	info_len = strlen(psk_digest) + strlen(psk_prefix) + 5;
>>
>> Where does the magic 5 come from?
>>
> Two bytes for the HASH ID, two bytes for the length field from
> HKDF-Expand-Label, and one byte for the space separator.

Well, that's information that needs to go here.  If at all possible
using a struct, but otherwise at least using a documented constant.