From nobody Wed Oct 1 23:30:09 2025 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 9948D217F29; Mon, 29 Sep 2025 04:00:20 +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=1759118422; cv=none; b=nP8kr2hTdT7iaCXO4D4/TSZp634GIXi2wZgfu0EUqyolmy4OPZ1bGr+uU5uxY+OwxDLlVeaA/EaBlDxmpoSR/QN7NpeuqKmrU4A6diZprFJ/QfSU9cz/HpaZe7yQnL0eu+WdWhrkwaEJMYiLg0tlye0mWmBx1MGhg8Okj0FAqDQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759118422; c=relaxed/simple; bh=GzR8CWkFmj4n7Shr66/XIXfc/gfCOIfMIxPRIPMtQko=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=IcKTwo37mvOjGNAV2fFAckhm8ssKYNcst9MptxiK54wNdH8/pAsgel+lQzBTupqoATCdpi26qm3hbezjIkCNnDL5xfsBsFbiGmXW/5cagwjKoqhgi9HBoZmXe7/cAl8zizRBFnCHGHQ52D0wapE5tczWlYQu/M836FBkz5hoE8M= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bv9+SsBf; 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="bv9+SsBf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BB764C116C6; Mon, 29 Sep 2025 04:00:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1759118420; bh=GzR8CWkFmj4n7Shr66/XIXfc/gfCOIfMIxPRIPMtQko=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bv9+SsBf61DEUMMWiV/8/pgmxj33eH1/esxc6yCHd5oY2gnux8wxqX/bhknRN7wNP qZFy3L5DTG/lXRFhAMHqGZYUJ6zl6w46OR16NQNHo60i75c+PutHLvHl2hw/uOSBqD 2NL+4vp5ahsivekza9oqfv9r4dWL3WggmWkeA7c2y7T4OzRh7UkPSlTR/fCrXRSkxG B2uyViZexKMBf9uR3ToHGEvi+vKyWCFiqrXEC0ww5ofov8eYOcypRNb503Yw6U7YS0 0sM2AOubPR7DFhasOKSwHXCNtZhB+tX5jLCVVv6KYioHrxt0YejOzt5mjhl8LiidM+ tBj2pyEDqGTSg== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org Cc: dpsmith@apertussolutions.com, ross.philipson@oracle.com, Jarkko Sakkinen , Jonathan McDowell , David Howells , Jarkko Sakkinen , Paul Moore , James Morris , "Serge E. Hallyn" , James Bottomley , Mimi Zohar , keyrings@vger.kernel.org (open list:KEYS/KEYRINGS), linux-security-module@vger.kernel.org (open list:SECURITY SUBSYSTEM), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v2 6/9] KEYS: trusted: Open code tpm2_buf_append() Date: Mon, 29 Sep 2025 06:59:35 +0300 Message-Id: <20250929035938.1773341-7-jarkko@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250929035938.1773341-1-jarkko@kernel.org> References: <20250929035938.1773341-1-jarkko@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: Jarkko Sakkinen tpm2_buf_append_auth() has only single call site and most of its parameters are redundant. Open code it to the call site. Remove illegit FIXME comment as there is no categorized bug and replace it with more sane comment about implementation (i.e. "non-opionated inline comment"). Reviewed-by: Jonathan McDowell Signed-off-by: Jarkko Sakkinen --- v2: - No changes. --- security/keys/trusted-keys/trusted_tpm2.c | 51 ++++------------------- 1 file changed, 9 insertions(+), 42 deletions(-) diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trus= ted-keys/trusted_tpm2.c index c414a7006d78..8e3b283a59b2 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -198,36 +198,6 @@ int tpm2_key_priv(void *context, size_t hdrlen, return 0; } =20 -/** - * tpm2_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer. - * - * @buf: an allocated tpm_buf instance - * @session_handle: session handle - * @nonce: the session nonce, may be NULL if not used - * @nonce_len: the session nonce length, may be 0 if not used - * @attributes: the session attributes - * @hmac: the session HMAC or password, may be NULL if not used - * @hmac_len: the session HMAC or password length, maybe 0 if not used - */ -static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle, - const u8 *nonce, u16 nonce_len, - u8 attributes, - const u8 *hmac, u16 hmac_len) -{ - tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len); - tpm_buf_append_u32(buf, session_handle); - tpm_buf_append_u16(buf, nonce_len); - - if (nonce && nonce_len) - tpm_buf_append(buf, nonce, nonce_len); - - tpm_buf_append_u8(buf, attributes); - tpm_buf_append_u16(buf, hmac_len); - - if (hmac && hmac_len) - tpm_buf_append(buf, hmac, hmac_len); -} - /** * tpm2_seal_trusted() - seal the payload of a trusted key * @@ -507,19 +477,16 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, options->blobauth_len); } else { /* - * FIXME: The policy session was generated outside the - * kernel so we don't known the nonce and thus can't - * calculate a HMAC on it. Therefore, the user can - * only really use TPM2_PolicyPassword and we must - * send down the plain text password, which could be - * intercepted. We can still encrypt the returned - * key, but that's small comfort since the interposer - * could repeat our actions with the exfiltrated - * password. + * The policy session is generated outside the kernel, and thus + * the password will end up being unencrypted on the bus, as + * HMAC nonce cannot be calculated for it. */ - tpm2_buf_append_auth(&buf, options->policyhandle, - NULL /* nonce */, 0, 0, - options->blobauth, options->blobauth_len); + tpm_buf_append_u32(&buf, 9 + options->blobauth_len); + tpm_buf_append_u32(&buf, options->policyhandle); + tpm_buf_append_u16(&buf, 0); + tpm_buf_append_u8(&buf, 0); + tpm_buf_append_u16(&buf, options->blobauth_len); + tpm_buf_append(&buf, options->blobauth, options->blobauth_len); if (tpm2_chip_auth(chip)) { tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_ENCRYPT, NULL, 0); } else { --=20 2.39.5