From patchwork Mon Sep 9 12:22:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 11137829 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 715B076 for ; Mon, 9 Sep 2019 12:22:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D7FA2196E for ; Mon, 9 Sep 2019 12:22:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="ZwlPUCMg"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="ZwlPUCMg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731689AbfIIMWX (ORCPT ); Mon, 9 Sep 2019 08:22:23 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:48312 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731677AbfIIMWW (ORCPT ); Mon, 9 Sep 2019 08:22:22 -0400 Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 7F87D8EE180; Mon, 9 Sep 2019 05:22:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1568031742; bh=i7MrhvQ94JMBQj1p8wKiylhyLzjjRYfsQm4gyztxsWs=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=ZwlPUCMge59+Lbf3+zTN10yyl4Tdi/aB4FTJXnIic9Xk3bwCK4CjamlvHMnGj4SXl q28wM68xLMRyN8//fbwr6prUuqOAscc7tsNI7vyqLuplBfEr44UMGxezXTWPQIZvba yeTWkSNFskCCpoNSn+zSCaq3trC/7xh1iTi6l2lo= Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id q4e4JzhYcOCP; Mon, 9 Sep 2019 05:22:22 -0700 (PDT) Received: from [192.168.6.117] (unknown [148.69.85.38]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id 3B5878EE105; Mon, 9 Sep 2019 05:22:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1568031742; bh=i7MrhvQ94JMBQj1p8wKiylhyLzjjRYfsQm4gyztxsWs=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=ZwlPUCMge59+Lbf3+zTN10yyl4Tdi/aB4FTJXnIic9Xk3bwCK4CjamlvHMnGj4SXl q28wM68xLMRyN8//fbwr6prUuqOAscc7tsNI7vyqLuplBfEr44UMGxezXTWPQIZvba yeTWkSNFskCCpoNSn+zSCaq3trC/7xh1iTi6l2lo= Message-ID: <1568031739.6613.36.camel@HansenPartnership.com> Subject: [PATCH v6 07/12] tpm2: add hmac checks to tpm2_pcr_extend() From: James Bottomley To: linux-integrity@vger.kernel.org Cc: linux-crypto@vger.kernel.org, linux-security-module@vger.kernel.org, Jarkko Sakkinen Date: Mon, 09 Sep 2019 13:22:19 +0100 In-Reply-To: <1568031408.6613.29.camel@HansenPartnership.com> References: <1568031408.6613.29.camel@HansenPartnership.com> X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org We use tpm2_pcr_extend() in trusted keys to extend a PCR to prevent a key from being re-loaded until the next reboot. To use this functionality securely, that extend must be protected by a session hmac. Signed-off-by: James Bottomley --- v3: add error handling to sessions --- drivers/char/tpm/tpm2-cmd.c | 28 +++++++++++----------------- 1 file changed, 11 insertions(+), 17 deletions(-) diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index d120b0a260eb..0012657d3617 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -223,13 +223,6 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, return rc; } -struct tpm2_null_auth_area { - __be32 handle; - __be16 nonce_size; - u8 attributes; - __be16 auth_size; -} __packed; - /** * tpm2_pcr_extend() - extend a PCR value * @@ -243,24 +236,23 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digests) { struct tpm_buf buf; - struct tpm2_null_auth_area auth_area; + struct tpm2_auth *auth; int rc; int i; - rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND); + rc = tpm2_start_auth_session(chip, &auth); if (rc) return rc; - tpm_buf_append_u32(&buf, pcr_idx); + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND); + if (rc) { + tpm2_end_auth_session(auth); + return rc; + } - auth_area.handle = cpu_to_be32(TPM2_RS_PW); - auth_area.nonce_size = 0; - auth_area.attributes = 0; - auth_area.auth_size = 0; + tpm_buf_append_name(&buf, auth, pcr_idx, NULL); + tpm_buf_append_hmac_session(&buf, auth, 0, NULL, 0); - tpm_buf_append_u32(&buf, sizeof(struct tpm2_null_auth_area)); - tpm_buf_append(&buf, (const unsigned char *)&auth_area, - sizeof(auth_area)); tpm_buf_append_u32(&buf, chip->nr_allocated_banks); for (i = 0; i < chip->nr_allocated_banks; i++) { @@ -269,7 +261,9 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, chip->allocated_banks[i].digest_size); } + tpm_buf_fill_hmac_session(&buf, auth); rc = tpm_transmit_cmd(chip, &buf, 0, "attempting extend a PCR value"); + rc = tpm_buf_check_hmac_response(&buf, auth, rc); tpm_buf_destroy(&buf);