From patchwork Thu Jun 23 16:42:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 584735 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 161CAC433EF for ; Thu, 23 Jun 2022 17:54:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235313AbiFWRyt (ORCPT ); Thu, 23 Jun 2022 13:54:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235310AbiFWRyC (ORCPT ); Thu, 23 Jun 2022 13:54:02 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECE6BAD19C; Thu, 23 Jun 2022 10:14:57 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 7E457B8249B; Thu, 23 Jun 2022 17:14:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C628DC3411B; Thu, 23 Jun 2022 17:14:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656004495; bh=Sc7HKxEJeYEuVloFrvPH89U8hxLdJn0guLvJxiMmWjY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GPWn/zQfK9wnq6+a6Bry39EinShZrrvRrSKRZPRABwHRpSeotcaTbUyCXcpY/F/0T 20PHPHUDhE/YoD6kzymuDcm2Zx0pgb7nCapE9OZ8j6j9TJEsqd/MLhqmpiSMTdzbMx et9NI3M74/If5JAhBKZh+jwLNDRN34F1Rj7LAUbE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, linux-crypto@vger.kernel.org, Andy Lutomirski , Jann Horn , Theodore Tso , Ard Biesheuvel , Eric Biggers , Herbert Xu , "Jason A. Donenfeld" Subject: [PATCH 4.19 056/234] random: initialize ChaCha20 constants with correct endianness Date: Thu, 23 Jun 2022 18:42:03 +0200 Message-Id: <20220623164344.650084424@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220623164343.042598055@linuxfoundation.org> References: <20220623164343.042598055@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org From: Eric Biggers commit a181e0fdb2164268274453b5b291589edbb9b22d upstream. On big endian CPUs, the ChaCha20-based CRNG is using the wrong endianness for the ChaCha20 constants. This doesn't matter cryptographically, but technically it means it's not ChaCha20 anymore. Fix it to always use the standard constants. Cc: linux-crypto@vger.kernel.org Cc: Andy Lutomirski Cc: Jann Horn Cc: Theodore Ts'o Acked-by: Ard Biesheuvel Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman --- drivers/char/random.c | 4 ++-- include/crypto/chacha20.h | 8 ++++++++ 2 files changed, 10 insertions(+), 2 deletions(-) --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -817,7 +817,7 @@ static bool __init crng_init_try_arch_ea static void crng_initialize_secondary(struct crng_state *crng) { - memcpy(&crng->state[0], "expand 32-byte k", 16); + chacha_init_consts(crng->state); _get_random_bytes(&crng->state[4], sizeof(__u32) * 12); crng_init_try_arch(crng); crng->init_time = jiffies - CRNG_RESEED_INTERVAL - 1; @@ -825,7 +825,7 @@ static void crng_initialize_secondary(st static void __init crng_initialize_primary(struct crng_state *crng) { - memcpy(&crng->state[0], "expand 32-byte k", 16); + chacha_init_consts(crng->state); _extract_entropy(&input_pool, &crng->state[4], sizeof(__u32) * 12, 0); if (crng_init_try_arch_early(crng) && trust_cpu && crng_init < 2) { invalidate_batched_entropy(); --- a/include/crypto/chacha20.h +++ b/include/crypto/chacha20.h @@ -24,4 +24,12 @@ int crypto_chacha20_setkey(struct crypto unsigned int keysize); int crypto_chacha20_crypt(struct skcipher_request *req); +static inline void chacha_init_consts(u32 *state) +{ + state[0] = 0x61707865; /* "expa" */ + state[1] = 0x3320646e; /* "nd 3" */ + state[2] = 0x79622d32; /* "2-by" */ + state[3] = 0x6b206574; /* "te k" */ +} + #endif