Re: [PATCH v2 0/4] smb: client: Use AES-CMAC library

Steve French
2026-04-19T01:36:52Z

merged into cifs-2.6.git for-next pending additional testing and review

On Sat, Apr 18, 2026 at 5:13 PM Eric Biggers <ebiggers@kernel.org> wrote:
>
> This series updates the SMB client to use the AES-CMAC library functions
> that were recently added, instead of a "cmac(aes)" crypto_shash. As
> usual, this simplifies the code considerably and is much more efficient.
>
> These patches were originally sent as patches 8-11 of the series
> https://lore.kernel.org/r/20260218213501.136844-1-ebiggers@kernel.org/
> The only change from that version was adding tags and rebasing.
> I also added some microbenchmark results below.
>
> This is intended to be taken through the smb tree, either 7.1 or 7.2
> depending on maintainer preference.
>
> A few microbenchmarks that demonstrate improved performance:
>
> - Total cycles spent in generate_key() during SMB3 mount
> decreased from 20640 to 10780 (3 calls total).
>
> - Total cycles spent in smb3_calc_signature() during SMB3 mount
> decreased from 177620 to 73180 (32 calls & 4255 bytes total).
>
> - Total cycles spent in smb3_calc_signature() while writing 10MB file
> decreased from 27551180 to 26628360 (10 calls & 10001392 bytes total)
>
> - Total cycles spent in smb3_calc_signature() while reading 10MB file
> decreased from 28390900 to 27879340 (14 calls & 10001781 bytes total)
>
> Note that my "before" numbers were taken from current mainline which has
> my changes that made the "cmac(aes)" crypto_shash a bit faster as well.
> So the speedup vs v7.0 is actually even greater.
>
> Eric Biggers (4):
> smb: client: Use AES-CMAC library for SMB3 signature calculation
> smb: client: Remove obsolete cmac(aes) allocation
> smb: client: Make generate_key() return void
> smb: client: Drop 'allocate_crypto' arg from smb*_calc_signature()
>
> fs/smb/client/Kconfig | 2 +-
> fs/smb/client/cifs_unicode.c | 1 +
> fs/smb/client/cifsencrypt.c | 62 ++++++-------------
> fs/smb/client/cifsfs.c | 1 -
> fs/smb/client/cifsglob.h | 7 +--
> fs/smb/client/cifsproto.h | 3 -
> fs/smb/client/misc.c | 57 -----------------
> fs/smb/client/sess.c | 11 ----
> fs/smb/client/smb2proto.h | 1 -
> fs/smb/client/smb2transport.c | 113 +++++++++-------------------------
> 10 files changed, 53 insertions(+), 205 deletions(-)
>
>
> base-commit: 8541d8f725c673db3bd741947f27974358b2e163
> --
> 2.53.0
>
>

--
Thanks,

Steve