Subject: Re: [PATCH 07/12] nvme: Implement In-Band authentication
To:     Hannes Reinecke <hare@suse.de>
Cc:     Christoph Hellwig <hch@lst.de>, Keith Busch <keith.busch@wdc.com>,
        linux-nvme@lists.infradead.org,
        Herbert Xu <herbert@gondor.apana.org.au>,
        David Miller <davem@davemloft.org>,
        linux-crypto@vger.kernel.org
References: <20211123123801.73197-1-hare@suse.de>
 <20211123123801.73197-8-hare@suse.de>
From:   Sagi Grimberg <sagi@grimberg.me>
Message-ID: <ffd1519b-1f39-898a-be7f-5d9db7377ad1@grimberg.me>
Date:   Tue, 23 Nov 2021 15:11:20 +0200
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> +int nvme_auth_generate_key(struct nvme_ctrl *ctrl, u8 *secret, bool set_ctrl)

Didn't we agree to pass the key pointer? i.e.
int nvme_auth_generate_key(struct nvme_dhchap_key **key, u8 *secret)

> +{
> +	struct nvme_dhchap_key *key;
> +	u8 key_hash;
> +
> +	if (!secret)
> +		return 0;
> +
> +	if (sscanf(secret, "DHHC-1:%hhd:%*s:", &key_hash) != 1)
> +		return -EINVAL;
> +
> +	/* Pass in the secret without the 'DHHC-1:XX:' prefix */
> +	key = nvme_auth_extract_key(secret + 10, key_hash);
> +	if (IS_ERR(key)) {
> +		dev_dbg(ctrl->device, "failed to extract key, error %ld\n",
> +			PTR_ERR(key));

The print here is slightly redundant - you already have prints inside
nvme_auth_extract_key already.

> +		return PTR_ERR(key);
> +	}
> +

Then we instead just do:
	*key = key;

> +	if (set_ctrl)
> +		ctrl->ctrl_key = key;
> +	else
> +		ctrl->host_key = key;
> +
> +	return 0;
> +}

...

> +EXPORT_SYMBOL_GPL(nvme_auth_generate_key);
> diff --git a/drivers/nvme/host/auth.h b/drivers/nvme/host/auth.h
> new file mode 100644
> index 000000000000..16e3d893d54a
> --- /dev/null
> +++ b/drivers/nvme/host/auth.h
> @@ -0,0 +1,33 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2021 Hannes Reinecke, SUSE Software Solutions
> + */
> +
> +#ifndef _NVME_AUTH_H
> +#define _NVME_AUTH_H
> +
> +#include <crypto/kpp.h>
> +
> +struct nvme_dhchap_key {
> +	u8 *key;
> +	size_t key_len;
> +	u8 key_hash;

Why not just name it len and hash? don't think the key_
prefix is useful...