Re: [PATCH 0/8] smb: client: More crypto library conversions
From: Enzo Matsumiya
Date: Mon Oct 13 2025 - 10:44:43 EST
Hi Eric,
On 10/11, Eric Biggers wrote:
This series converts fs/smb/client/ to access SHA-512, HMAC-SHA256, MD5,
and HMAC-MD5 using the library APIs instead of crypto_shash.
This simplifies the code significantly. It also slightly improves
performance, as it eliminates unnecessary overhead.
Tested with Samba with all SMB versions, with mfsymlinks in the mount
options, 'server min protocol = NT1' and 'server signing = required' in
smb.conf, and doing a simple file data and symlink verification test.
That seems to cover all the modified code paths.
However, with SMB 1.0 I get "CIFS: VFS: SMB signature verification
returned error = -13", regardless of whether this series is applied or
not. Presumably, testing that case requires some other setting I
couldn't find.
Regardless, these are straightforward conversions and all the actual
crypto is exactly the same as before, as far as I can tell.
I think the overall series looks good and do a great cleanup.
Just a minor nit about fips_enabled: since it's now being handled
explicitly (rather than an error on cifs_alloc_hash() currently), I
think it makes sense to move the check to mount code path when
'sectype == NTLMv2' (I don't particularly care about SMB1, but
something similar can be done for 'smb1 && sign' cases I guess).
Eric Biggers (8):
smb: client: Use SHA-512 library for SMB3.1.1 preauth hash
smb: client: Use HMAC-SHA256 library for key generation
smb: client: Use HMAC-SHA256 library for SMB2 signature calculation
smb: client: Use MD5 library for M-F symlink hashing
smb: client: Use MD5 library for SMB1 signature calculation
smb: client: Use HMAC-MD5 library for NTLMv2
smb: client: Remove obsolete crypto_shash allocations
smb: client: Consolidate cmac(aes) shash allocation
fs/smb/client/Kconfig | 7 +-
fs/smb/client/cifsencrypt.c | 201 +++++++++++++---------------------
fs/smb/client/cifsfs.c | 4 -
fs/smb/client/cifsglob.h | 3 -
fs/smb/client/cifsproto.h | 10 +-
fs/smb/client/link.c | 31 +-----
fs/smb/client/sess.c | 2 +-
fs/smb/client/smb2misc.c | 53 ++-------
fs/smb/client/smb2proto.h | 8 +-
fs/smb/client/smb2transport.c | 164 +++++----------------------
10 files changed, 131 insertions(+), 352 deletions(-)
base-commit: 67029a49db6c1f21106a1b5fcdd0ea234a6e0711
--
2.51.0
Cheers,
Enzo