From patchwork Wed Jul 3 19:04:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 809466 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5F7F3185E4F for ; Wed, 3 Jul 2024 19:05:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720033511; cv=none; b=s+6Gy7Sd5nDdJnHp/5wP0x+6GH4WZ6OE2PxgAhRf0CjQjH5r+yxNt2gZzgZLRgHzYAEGjd+sY7BlWQcn8VtOWyKIm4+naKsr7AH6Jiu0k79CHvmDsHWXUPyZdLzABzywxDXzwfIPdARHTrk8z3f+1XzwlJp0On5vIAgBdmUfDyA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720033511; c=relaxed/simple; bh=2Vz6hJ0h/TklevmbNfooUTLTupNNk8r/DeolGS3CKWg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Vzd3na/YuOpCManSHCCaEM15HiaexQAkWQocn66JDm2ecDbTBKRxilDHTcqgTP5NPZtThSCwDquXKdhpyiKSqB9VHZF9qpPfG/SWb1kBY4xLY+emkWQjDqkCo0YW1RjeTb+AAB4zQIclQJtTUb2q0uasnVpbkee3Fy8HRDktuZQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ODE1v+ey; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ODE1v+ey" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2523C2BD10; Wed, 3 Jul 2024 19:05:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720033510; bh=2Vz6hJ0h/TklevmbNfooUTLTupNNk8r/DeolGS3CKWg=; h=From:To:Cc:Subject:Date:From; b=ODE1v+ey7nJvOvCjIivqGz1zkiGI0vIW11lqLynWKg5NOIBLM26jZ3yzRXMSIO6Lz OX2BFWifslAUEKZMZCVKo/2XikhvDwPnZwvz+YESaV0ZcQtxDLHlVEAV8keAlU+rdC vxsTq5CBy2jgd65hLl9LEUSVexLIEtyfyz/Rzvx+/RscHGW+njBsZzQFbjznpQUVXx K4hdLP7ml2+0xDRC/1Lz+RBWUdV9+OtK1id/VF1XfK85KYAWytUtSBInaydKl/FVWn fcvi1g6NFDtyP1Ep/sF2kbRCnQzcxQ3NYqLddEY5U/+o+s2WB7ioYY2OjNaottXpDO ULYlF+HIDVqbw== From: Eric Biggers To: linux-crypto@vger.kernel.org Cc: Sami Tolvanen , Ard Biesheuvel Subject: [PATCH] crypto: testmgr - generate power-of-2 lengths more often Date: Wed, 3 Jul 2024 12:04:31 -0700 Message-ID: <20240703190431.6513-1-ebiggers@kernel.org> X-Mailer: git-send-email 2.45.2 Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Eric Biggers Implementations of hash functions often have special cases when lengths are a multiple of the hash function's internal block size (e.g. 64 for SHA-256, 128 for SHA-512). Currently, when the fuzz testing code generates lengths, it doesn't prefer any length mod 64 over any other. This limits the coverage of these special cases. Therefore, this patch updates the fuzz testing code to generate power-of-2 lengths and divide messages exactly in half a bit more often. Reviewed-by: Sami Tolvanen Acked-by: Ard Biesheuvel Signed-off-by: Eric Biggers --- This is the same as https://lore.kernel.org/linux-crypto/20240621165922.77672-3-ebiggers@kernel.org/, just resent as a standalone patch. crypto/testmgr.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) base-commit: 95c0f5c3b8bb7acdc5c4f04bc6a7d3f40d319e9e diff --git a/crypto/testmgr.c b/crypto/testmgr.c index a780b615f8c6..f02cb075bd68 100644 --- a/crypto/testmgr.c +++ b/crypto/testmgr.c @@ -914,18 +914,24 @@ static unsigned int generate_random_length(struct rnd_state *rng, { unsigned int len = prandom_u32_below(rng, max_len + 1); switch (prandom_u32_below(rng, 4)) { case 0: - return len % 64; + len %= 64; + break; case 1: - return len % 256; + len %= 256; + break; case 2: - return len % 1024; + len %= 1024; + break; default: - return len; + break; } + if (len && prandom_u32_below(rng, 4) == 0) + len = rounddown_pow_of_two(len); + return len; } /* Flip a random bit in the given nonempty data buffer */ static void flip_random_bit(struct rnd_state *rng, u8 *buf, size_t size) { @@ -1017,10 +1023,12 @@ static char *generate_random_sgl_divisions(struct rnd_state *rng, unsigned int this_len; const char *flushtype_str; if (div == &divs[max_divs - 1] || prandom_bool(rng)) this_len = remaining; + else if (prandom_u32_below(rng, 4) == 0) + this_len = (remaining + 1) / 2; else this_len = prandom_u32_inclusive(rng, 1, remaining); div->proportion_of_total = this_len; if (prandom_u32_below(rng, 4) == 0)