From nobody Sun Feb 8 06:05:44 2026 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 7E6D4286408; Sun, 26 Oct 2025 05:53:05 +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=1761457988; cv=none; b=NKvLTVayIHYcqC9MctfU2Ny8jzOR3M2Mlsi5AkrAbMJel6TS/LfgvVn4QwW201ruTE8l8KtXjkVILFbkA03oLENF2eEbxYixU33n1nke20FWvZ8vLqMVLQGMc5LDCoffme21ZULt5gUQJXS7WExUqpDUMRci/9oWUFlArockGC8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761457988; c=relaxed/simple; bh=G4phGjZg/4DyxMiZScpeB5F56Kh8gOR6USagGkBx7Vo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KsFj+4Axn1+dMwAIwzxWPsj2WuMcJJn6J0AArpx6heYOUEbpNsuDH/UFhvLqsST5cMRik/gP3gFVVRjRC1DMGnrgqFOJaiWlYkCyTVENr6A7HJF5Dh6lzS1KksC8VA8EVRVAyyTaxEu5EIV27hBnb4kbgJrVUh2Rm/zGCL19PEE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TlTvEPgl; 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="TlTvEPgl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98D9DC4AF09; Sun, 26 Oct 2025 05:53:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761457985; bh=G4phGjZg/4DyxMiZScpeB5F56Kh8gOR6USagGkBx7Vo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TlTvEPglQOHat1LvQgZUeyeuH7Hcljru/KjtGuDlPGeis3n5PDywGuUR25jVngEOp T5yZXcLFZ6og46oOZMuQ7zxtDth/L4dx3COFvfMV2Ow2EFNErD0glGUlcdwh7UeBOE wWenUYvUP+Ih//cuIDUWWg4XEVrTtksjyp3Hrr6JIDvEU1OCybt2M1YcdmsLDis+mU eWoRbzOIp5aaz5BtZ4nWu/8zl2nG9wqJV/h4GPP4EX2ZBDcXb8UQ5NFva900cfcsXS Uah4c0CN9RaIVGM+Q7TDU4TRcbg3JQiuhVNtJMXM6hlZYSFRY4ishXF3Nd3XaNcyhX 3XHR8lijJDvvQ== From: Eric Biggers To: linux-crypto@vger.kernel.org Cc: David Howells , Ard Biesheuvel , "Jason A . Donenfeld" , Eric Biggers , Holger Dengler , Harald Freudenberger , Herbert Xu , linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 04/15] lib/crypto: sha3: Move SHA3 Iota step mapping into round function Date: Sat, 25 Oct 2025 22:50:21 -0700 Message-ID: <20251026055032.1413733-5-ebiggers@kernel.org> X-Mailer: git-send-email 2.51.1.dirty In-Reply-To: <20251026055032.1413733-1-ebiggers@kernel.org> References: <20251026055032.1413733-1-ebiggers@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: David Howells In crypto/sha3_generic.c, the keccakf() function calls keccakf_round() to do four of Keccak-f's five step mappings. However, it does not do the Iota step mapping - presumably because that is dependent on round number, whereas Theta, Rho, Pi and Chi are not. Note that the keccakf_round() function needs to be explicitly non-inlined on certain architectures as gcc's produced output will (or used to) use over 1KiB of stack space if inlined. Now, this code was copied more or less verbatim into lib/crypto/sha3.c, so that has the same aesthetic issue. Fix this there by passing the round number into sha3_keccakf_one_round_generic() and doing the Iota step mapping there. crypto/sha3_generic.c is left untouched as that will be converted to use lib/crypto/sha3.c at some point. Suggested-by: Eric Biggers Signed-off-by: David Howells Signed-off-by: Eric Biggers --- lib/crypto/sha3.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/lib/crypto/sha3.c b/lib/crypto/sha3.c index 049be8414de26..ee7a2ca92b2c5 100644 --- a/lib/crypto/sha3.c +++ b/lib/crypto/sha3.c @@ -46,11 +46,11 @@ static const u64 sha3_keccakf_rndc[SHA3_KECCAK_ROUNDS] = =3D { }; =20 /* * Perform a single round of Keccak mixing. */ -static SHA3_INLINE void sha3_keccakf_one_round_generic(u64 st[25]) +static SHA3_INLINE void sha3_keccakf_one_round_generic(u64 st[25], int rou= nd) { u64 t[5], tt, bc[5]; =20 /* Theta */ bc[0] =3D st[0] ^ st[5] ^ st[10] ^ st[15] ^ st[20]; @@ -147,10 +147,13 @@ static SHA3_INLINE void sha3_keccakf_one_round_generi= c(u64 st[25]) st[20] ^=3D bc[ 0]; st[21] ^=3D bc[ 1]; st[22] ^=3D bc[ 2]; st[23] ^=3D bc[ 3]; st[24] ^=3D bc[ 4]; + + /* Iota */ + st[0] ^=3D sha3_keccakf_rndc[round]; } =20 /* Generic implementation of the Keccak-f[1600] permutation */ static void sha3_keccakf_generic(struct sha3_state *state) { @@ -161,15 +164,12 @@ static void sha3_keccakf_generic(struct sha3_state *s= tate) */ =20 for (int i =3D 0; i < ARRAY_SIZE(state->words); i++) state->native_words[i] =3D le64_to_cpu(state->words[i]); =20 - for (int round =3D 0; round < SHA3_KECCAK_ROUNDS; round++) { - sha3_keccakf_one_round_generic(state->native_words); - /* Iota */ - state->native_words[0] ^=3D sha3_keccakf_rndc[round]; - } + for (int round =3D 0; round < SHA3_KECCAK_ROUNDS; round++) + sha3_keccakf_one_round_generic(state->native_words, round); =20 for (int i =3D 0; i < ARRAY_SIZE(state->words); i++) state->words[i] =3D cpu_to_le64(state->native_words[i]); } =20 --=20 2.51.1.dirty