From patchwork Tue Oct 24 01:15:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 13433858 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 D404BC25B6B for ; Tue, 24 Oct 2023 01:16:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231847AbjJXBQb (ORCPT ); Mon, 23 Oct 2023 21:16:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36454 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231963AbjJXBQQ (ORCPT ); Mon, 23 Oct 2023 21:16:16 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A927E10DE; Mon, 23 Oct 2023 18:16:08 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E45BAC433C8; Tue, 24 Oct 2023 01:16:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1698110168; bh=ZdQqdBn4UrJLrghWqEUDW/8ikCU9oiCOvcpS1PL5Ftc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SFk/3BJi45tRWoygTOJ3Iix08XMa0hD5CXMxUAAmwmEbANZYKU/EYBERbW5KU7HhD 188Ruj7xi6Xo7vcnVClKwE74h9/XHeeklHwTZSl9sLh6q3TLSB7LOUS7bUSNa6DJPU rOXlNVFjExh5Lk8fObLODUKUg6ytbt5S1MyoD/0z5VfB387GpZ5FUhpnjLAS8AroRc NJ2FRv5gt+wIvs2GdFqnWR4lDXs1XbQg+uifuP7Ikc3lBAX3gVfN0VwiKiblswUMTU FR1wny0FewE6C8jyJiFxmYeJC6RbAg/vH8IzUIVIeC1xIaQCiudyP7+WxfEAry5aIL hs6DPmAG9btvQ== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org Cc: keyrings@vger.kernel.org, Jarkko Sakkinen , James Bottomley , William Roberts , Stefan Berger , David Howells , Jason Gunthorpe , Mimi Zohar , James Bottomley , Paul Moore , James Morris , "Serge E. Hallyn" , linux-security-module@vger.kernel.org (open list:SECURITY SUBSYSTEM), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v3 6/6] KEYS: trusted: tpm2: Use struct tpm_buf for sized buffers Date: Tue, 24 Oct 2023 04:15:24 +0300 Message-ID: <20231024011531.442587-7-jarkko@kernel.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231024011531.442587-1-jarkko@kernel.org> References: <20231024011531.442587-1-jarkko@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Take advantage of the new sized buffer (TPM2B) mode of struct tpm_buf in tpm2_seal_trusted(). This allows to add robustness to the command construction without requiring to calculate buffer sizes manually. Signed-off-by: Jarkko Sakkinen --- v2: * Use tpm_buf_read_* --- security/keys/trusted-keys/trusted_tpm2.c | 51 +++++++++++++---------- 1 file changed, 29 insertions(+), 22 deletions(-) diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index c41f30770138..5d262306184c 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -228,8 +228,9 @@ int tpm2_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload, struct trusted_key_options *options) { + off_t offset = TPM_HEADER_SIZE; + struct tpm_buf buf, sized; int blob_len = 0; - struct tpm_buf buf; u32 hash; u32 flags; int i; @@ -258,6 +259,13 @@ int tpm2_seal_trusted(struct tpm_chip *chip, return rc; } + rc = tpm_buf_init(&sized, true, true); + if (rc) { + tpm_buf_destroy(&buf); + tpm_put_ops(chip); + return rc; + } + tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE); tpm_buf_append_u32(&buf, options->keyhandle); tpm2_buf_append_auth(&buf, TPM2_RS_PW, @@ -267,36 +275,36 @@ int tpm2_seal_trusted(struct tpm_chip *chip, TPM_DIGEST_SIZE); /* sensitive */ - tpm_buf_append_u16(&buf, 4 + options->blobauth_len + payload->key_len); + tpm_buf_append_u16(&sized, options->blobauth_len); - tpm_buf_append_u16(&buf, options->blobauth_len); if (options->blobauth_len) - tpm_buf_append(&buf, options->blobauth, options->blobauth_len); + tpm_buf_append(&sized, options->blobauth, options->blobauth_len); - tpm_buf_append_u16(&buf, payload->key_len); - tpm_buf_append(&buf, payload->key, payload->key_len); + tpm_buf_append_u16(&sized, payload->key_len); + tpm_buf_append(&sized, payload->key, payload->key_len); + tpm_buf_append(&buf, sized.data, sized.length); /* public */ - tpm_buf_append_u16(&buf, 14 + options->policydigest_len); - tpm_buf_append_u16(&buf, TPM_ALG_KEYEDHASH); - tpm_buf_append_u16(&buf, hash); + tpm_buf_init(&sized, false, true); + tpm_buf_append_u16(&sized, TPM_ALG_KEYEDHASH); + tpm_buf_append_u16(&sized, hash); /* key properties */ flags = 0; flags |= options->policydigest_len ? 0 : TPM2_OA_USER_WITH_AUTH; - flags |= payload->migratable ? 0 : (TPM2_OA_FIXED_TPM | - TPM2_OA_FIXED_PARENT); - tpm_buf_append_u32(&buf, flags); + flags |= payload->migratable ? 0 : (TPM2_OA_FIXED_TPM | TPM2_OA_FIXED_PARENT); + tpm_buf_append_u32(&sized, flags); /* policy */ - tpm_buf_append_u16(&buf, options->policydigest_len); + tpm_buf_append_u16(&sized, options->policydigest_len); if (options->policydigest_len) - tpm_buf_append(&buf, options->policydigest, - options->policydigest_len); + tpm_buf_append(&sized, options->policydigest, options->policydigest_len); /* public parameters */ - tpm_buf_append_u16(&buf, TPM_ALG_NULL); - tpm_buf_append_u16(&buf, 0); + tpm_buf_append_u16(&sized, TPM_ALG_NULL); + tpm_buf_append_u16(&sized, 0); + + tpm_buf_append(&buf, sized.data, sized.length); /* outside info */ tpm_buf_append_u16(&buf, 0); @@ -313,21 +321,20 @@ int tpm2_seal_trusted(struct tpm_chip *chip, if (rc) goto out; - blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]); + blob_len = tpm_buf_read_u32(&buf, &offset); if (blob_len > MAX_BLOB_SIZE) { rc = -E2BIG; goto out; } - if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) { + if (buf.length - offset < blob_len) { rc = -EFAULT; goto out; } - blob_len = tpm2_key_encode(payload, options, - &buf.data[TPM_HEADER_SIZE + 4], - blob_len); + blob_len = tpm2_key_encode(payload, options, &buf.data[offset], blob_len); out: + tpm_buf_destroy(&sized); tpm_buf_destroy(&buf); if (rc > 0) {