From patchwork Sat Aug 31 09:20:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Beh=C3=BAn?= X-Patchwork-Id: 13785980 X-Patchwork-Delegate: arnd@arndb.de 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 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.lore.kernel.org (Postfix) with ESMTPS id 03817CA101D for ; Sat, 31 Aug 2024 09:21:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) id DFCB4C4CEC5; Sat, 31 Aug 2024 09:21:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D7072C4CEC8; Sat, 31 Aug 2024 09:21:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725096067; bh=AwT5qzxhp9vQo1GlsE1SlB7a3vvarFYBTj9yOuK6/iA=; h=From:List-Id:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q8QZzeedWqfWgdPXplTYnwFIDjRI7dihxVXzRFRK5CZUKf9RsGuoq9NwbzXywJYL7 P1JSJ7sAsqeAMaY9kcF13n4k7oRYTORq62rOTUrkQCbMLT8AUYFDrSeYwVQJtvFkgO WKijPh516iIub1HwAJB/M4UdCI46Z9D4xdCZI9/XhdgYg0+XSV1cYDZv/Dpqw6+w4r +Or/yRK+jLkYfAqD7jmpv5niV5U7YXpIQSo7Ydv9DVd7oj8Etr1bACsqfhGKm5TwSB rkqWOV0tlWIo34D7L7fKRKpR/heKWpi1VrzBss7Fr8IxMvIMszY9x7tHOu5SObDBwq RftG3BjrSY13g== From: =?utf-8?q?Marek_Beh=C3=BAn?= List-Id: To: Gregory CLEMENT , Andrew Lunn , Arnd Bergmann , soc@kernel.org, arm@kernel.org, Andy Shevchenko , Hans de Goede , =?utf-8?q?Ilpo_J=C3=A4rvinen?= Cc: =?utf-8?q?Marek_Beh=C3=BAn?= Subject: [PATCH v5 04/16] firmware: turris-mox-rwtm: Hide signature related constants behind macros Date: Sat, 31 Aug 2024 11:20:38 +0200 Message-ID: <20240831092050.23093-5-kabel@kernel.org> X-Mailer: git-send-email 2.44.2 In-Reply-To: <20240831092050.23093-1-kabel@kernel.org> References: <20240831092050.23093-1-kabel@kernel.org> MIME-Version: 1.0 Hide signature generation related constants behind macros instead of hardcoding the values. Use SHA512_DIGEST_SIZE from crypto/sha2.h instead of hardcoded 64 as the message size. Signed-off-by: Marek Behún Reviewed-by: Andy Shevchenko --- drivers/firmware/turris-mox-rwtm.c | 36 ++++++++++++++++++------------ 1 file changed, 22 insertions(+), 14 deletions(-) diff --git a/drivers/firmware/turris-mox-rwtm.c b/drivers/firmware/turris-mox-rwtm.c index 8875c35f9b19..cf8c605d99ef 100644 --- a/drivers/firmware/turris-mox-rwtm.c +++ b/drivers/firmware/turris-mox-rwtm.c @@ -5,6 +5,7 @@ * Copyright (C) 2019, 2024 Marek Behún */ +#include #include #include #include @@ -31,6 +32,11 @@ * https://gitlab.labs.nic.cz/turris/mox-boot-builder/tree/master/wtmi. */ +#define MOX_ECC_NUMBER_WORDS 17 +#define MOX_ECC_NUMBER_LEN (MOX_ECC_NUMBER_WORDS * sizeof(u32)) + +#define MOX_ECC_SIGNATURE_WORDS (2 * MOX_ECC_NUMBER_WORDS) + #define MBOX_STS_SUCCESS (0 << 30) #define MBOX_STS_FAIL (1 << 30) #define MBOX_STS_BADCMD (2 << 30) @@ -85,7 +91,7 @@ struct mox_rwtm { * from userspace. */ struct dentry *debugfs_root; - u32 last_sig[34]; + u32 last_sig[MOX_ECC_SIGNATURE_WORDS]; bool last_sig_done; #endif }; @@ -341,18 +347,18 @@ static ssize_t do_sign_read(struct file *file, char __user *buf, size_t len, struct mox_rwtm *rwtm = file->private_data; ssize_t ret; - /* only allow one read, of 136 bytes, from position 0 */ + /* only allow one read, of whole signature, from position 0 */ if (*ppos != 0) return 0; - if (len < 136) + if (len < sizeof(rwtm->last_sig)) return -EINVAL; if (!rwtm->last_sig_done) return -ENODATA; - /* 2 arrays of 17 32-bit words are 136 bytes */ - ret = simple_read_from_buffer(buf, len, ppos, rwtm->last_sig, 136); + ret = simple_read_from_buffer(buf, len, ppos, rwtm->last_sig, + sizeof(rwtm->last_sig)); rwtm->last_sig_done = false; return ret; @@ -367,8 +373,7 @@ static ssize_t do_sign_write(struct file *file, const char __user *buf, loff_t dummy = 0; ssize_t ret; - /* the input is a SHA-512 hash, so exactly 64 bytes have to be read */ - if (len != 64) + if (len != SHA512_DIGEST_SIZE) return -EINVAL; /* if last result is not zero user has not read that information yet */ @@ -389,17 +394,18 @@ static ssize_t do_sign_write(struct file *file, const char __user *buf, * 3. Address of the buffer where ECDSA signature value S shall be * stored by the rWTM firmware. */ - memset(rwtm->buf, 0, 4); - ret = simple_write_to_buffer(rwtm->buf + 4, 64, &dummy, buf, len); + memset(rwtm->buf, 0, sizeof(u32)); + ret = simple_write_to_buffer(rwtm->buf + sizeof(u32), + SHA512_DIGEST_SIZE, &dummy, buf, len); if (ret < 0) goto unlock_mutex; - be32_to_cpu_array(rwtm->buf, rwtm->buf, 17); + be32_to_cpu_array(rwtm->buf, rwtm->buf, MOX_ECC_NUMBER_WORDS); msg.command = MBOX_CMD_SIGN; msg.args[0] = 1; msg.args[1] = rwtm->buf_phys; - msg.args[2] = rwtm->buf_phys + 68; - msg.args[3] = rwtm->buf_phys + 2 * 68; + msg.args[2] = rwtm->buf_phys + MOX_ECC_NUMBER_LEN; + msg.args[3] = rwtm->buf_phys + 2 * MOX_ECC_NUMBER_LEN; ret = mbox_send_message(rwtm->mbox, &msg); if (ret < 0) goto unlock_mutex; @@ -417,8 +423,10 @@ static ssize_t do_sign_write(struct file *file, const char __user *buf, * computed by the rWTM firmware and convert their words from * LE to BE. */ - memcpy(rwtm->last_sig, rwtm->buf + 68, 136); - cpu_to_be32_array(rwtm->last_sig, rwtm->last_sig, 34); + memcpy(rwtm->last_sig, rwtm->buf + MOX_ECC_NUMBER_LEN, + sizeof(rwtm->last_sig)); + cpu_to_be32_array(rwtm->last_sig, rwtm->last_sig, + MOX_ECC_SIGNATURE_WORDS); rwtm->last_sig_done = true; mutex_unlock(&rwtm->busy);