Re: [PATCH 12/21] nvme-auth: common: use crypto library in nvme_auth_derive_tls_psk()

From: Hannes Reinecke

Date: Tue Mar 03 2026 - 02:40:21 EST

On 3/2/26 08:59, Eric Biggers wrote:
For the HKDF-Expand-Label computation in nvme_auth_derive_tls_psk(), use
the crypto library instead of crypto_shash and crypto/hkdf.c.

While this means the HKDF "helper" functions are no longer utilized,
they clearly weren't buying us much: it's simpler to just inline the
HMAC computations directly, and this code needs to be tested anyway. (A
similar result was seen in fs/crypto/. As a result, this eliminates the
last user of crypto/hkdf.c, which we'll be able to remove as well.)

As usual this is also a lot more efficient, eliminating the allocation
of a transformation object and multiple other dynamic allocations.

Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
drivers/nvme/common/auth.c | 156 +++++++++++++------------------------
1 file changed, 53 insertions(+), 103 deletions(-)

Reviewed-by: Hannes Reinecke <hare@xxxxxxx>

Cheers,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
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