linux-kernel - Re: [PATCH v2 00/15] SHA-3 library

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251029163216.GA1603@sol>
Date: Wed, 29 Oct 2025 09:32:16 -0700
From: Eric Biggers <ebiggers@...nel.org>
To: Harald Freudenberger <freude@...ux.ibm.com>
Cc: linux-crypto@...r.kernel.org, David Howells <dhowells@...hat.com>,
	Ard Biesheuvel <ardb@...nel.org>,
	"Jason A . Donenfeld" <Jason@...c4.com>,
	Holger Dengler <dengler@...ux.ibm.com>,
	Herbert Xu <herbert@...dor.apana.org.au>,
	linux-arm-kernel@...ts.infradead.org, linux-s390@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 00/15] SHA-3 library

On Wed, Oct 29, 2025 at 10:30:40AM +0100, Harald Freudenberger wrote:
> > If the s390 folks could re-test the s390 optimized SHA-3 code (by
> > enabling CRYPTO_LIB_SHA3_KUNIT_TEST and CRYPTO_LIB_BENCHMARK), that
> > would be helpful.  QEMU doesn't support the instructions it uses.  Also,
> > it would be helpful to provide the benchmark output from just before
> > "lib/crypto: s390/sha3: Add optimized Keccak function", just after it,
> > and after "lib/crypto: s390/sha3: Add optimized one-shot SHA-3 digest
> > functions".  Then we can verify that each change is useful.
[...]
> 
> Picked this series from your ebiggers repo branch sha3-lib-v2.
> Build on s390 runs without any complains, no warnings.
> As recommended I enabled the KUNIT option and also CRYPTO_SELFTESTS_FULL.
> With an "modprobe tcrypt" I enforced to run the selftests
> and in parallel I checked that the s390 specific CPACF instructions
> are really used (can be done with the pai command and check for
> the KIMD_SHA3_* counters). Also ran some AF-alg tests to verify
> all the the sha3 hashes and check for thread safety.
> All this ran without any findings. However there are NO performance
> related tests involved.

Thanks!  Just to confirm, did you actually run the sha3 KUnit test and
verify that all its test cases passed?  That's the most important one.
It also includes a benchmark, if CONFIG_CRYPTO_LIB_BENCHMARK=y is
enabled, and I was hoping to see your results from that after each
change.  The results get printed to the kernel log when the test runs.

> What's a little bit tricky here is that the sha3 lib is statically
> build into the kernel. So no chance to unload/load this as a module.
> For sha1 and the sha2 stuff I can understand the need to have this
> statically enabled in the kernel. Sha3 is only supposed to be available
> as backup in case of sha2 deficiencies. So I can't see why this is
> really statically needed.

CONFIG_CRYPTO_LIB_SHA3 is a tristate option.  It can be either built-in
or a loadable module, depending on what other kconfig options select it.
Same as all the other crypto library modules.

- Eric