From patchwork Wed May 4 23:20:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Evan Green X-Patchwork-Id: 12838917 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 BF061C43219 for ; Wed, 4 May 2022 23:59:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1383743AbiEEAA2 (ORCPT ); Wed, 4 May 2022 20:00:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237222AbiEDXZF (ORCPT ); Wed, 4 May 2022 19:25:05 -0400 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4FE204D9EE for ; Wed, 4 May 2022 16:21:20 -0700 (PDT) Received: by mail-pl1-x632.google.com with SMTP id j8so2815649pll.11 for ; Wed, 04 May 2022 16:21:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=kOErKHWJujqLaWOkztm6Xtg2ojuojMVj+Fr4mvN2bHY=; b=jYMzIpOHiHfN+4bIj/5tb5+YNcUhAnEFKP1KNaU1R74wa7pXmowvB0kqxvMPbZiDX0 ce4lExddCHHxXaFEgN/WpLdcoE4xyxvt+gbwyI00DWN4BxPSmJibPrsZuKSJB2Qp1sj2 rog+u88u3r0YgEA4474NdK7ebeueNp8BCQJW8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=kOErKHWJujqLaWOkztm6Xtg2ojuojMVj+Fr4mvN2bHY=; b=jj6EZXj4SsWugZVl/DqUcixsYAmI5vx68AHfCzpmj4l0gACU2M81wvNqJew1cMotYt bqgBZK3H89jmidXr+E5Ph59XSHIL+Gd38ED1hoCTy8fvTlK9qSIjHapsFtTzTrXL/prp wnGb2Gtea66GrH/5xQ+VHJiHtnvJeTw9B9gePg1Y6DWuMke+PryT1KpEqJMumgiZOgPL m+/DoKZWj8RkZQNHtr0sIa2CzSrFBFmajmcA50siDZAUprJz1+QR3lEISsC7e5r4uJLe 4eB6M5RUqVo4MxLPlV+MZzgGbC7RRsOuNPFEyAhJkjuQp87Megsqa6OaiDKRXHMV3npD cMjQ== X-Gm-Message-State: AOAM5306lIHZIQOAQafvSZX8UdJwO2mDOGoZc+jW+ExEi5D1QxbRqHFS V54kq7OlhEMoxJrahAfhZgPxPg== X-Google-Smtp-Source: ABdhPJyyPuRAXT9i6lNMadNV8m2hItTolkkOwTobBqzOGh/jcV0ZGvreW1VB1z9+Q9zAcbwiLZEuOg== X-Received: by 2002:a17:902:da90:b0:15e:adc2:191d with SMTP id j16-20020a170902da9000b0015eadc2191dmr14406754plx.134.1651706479816; Wed, 04 May 2022 16:21:19 -0700 (PDT) Received: from evgreen-glaptop.lan ([98.47.98.87]) by smtp.gmail.com with ESMTPSA id q12-20020a170902f78c00b0015e8d4eb2d6sm1901pln.288.2022.05.04.16.21.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 May 2022 16:21:19 -0700 (PDT) From: Evan Green To: linux-kernel@vger.kernel.org Cc: Matthew Garrett , dlunev@google.com, zohar@linux.ibm.com, jejb@linux.ibm.com, linux-integrity@vger.kernel.org, corbet@lwn.net, rjw@rjwysocki.net, gwendal@chromium.org, jarkko@kernel.org, linux-pm@vger.kernel.org, Matthew Garrett , Matthew Garrett , Evan Green , Hao Wu , Jason Gunthorpe , Peter Huewe , axelj Subject: [PATCH 01/10] tpm: Add support for in-kernel resetting of PCRs Date: Wed, 4 May 2022 16:20:53 -0700 Message-Id: <20220504161439.1.I776854f47e3340cc2913ed4d8ecdd328048b73c3@changeid> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20220504232102.469959-1-evgreen@chromium.org> References: <20220504232102.469959-1-evgreen@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Matthew Garrett Add an internal command for resetting a PCR. This will be used by the encrypted hibernation code to set PCR23 to a known value. The hibernation code will seal the hibernation key with a policy specifying PCR23 be set to this known value as a mechanism to ensure that the hibernation key is genuine. But to do this repeatedly, resetting the PCR is necessary as well. From: Matthew Garrett Signed-off-by: Matthew Garrett Signed-off-by: Evan Green --- Matthew's original version of this patch was at: https://patchwork.kernel.org/patch/12096487/ drivers/char/tpm/tpm-interface.c | 28 +++++++++++++++++++++++++ drivers/char/tpm/tpm.h | 2 ++ drivers/char/tpm/tpm1-cmd.c | 34 ++++++++++++++++++++++++++++++ drivers/char/tpm/tpm2-cmd.c | 36 ++++++++++++++++++++++++++++++++ include/linux/tpm.h | 7 +++++++ 5 files changed, 107 insertions(+) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 1621ce8187052c..17b8643ee109c2 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -342,6 +342,34 @@ int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, } EXPORT_SYMBOL_GPL(tpm_pcr_extend); +/** + * tpm_pcr_reset - reset the specified PCR + * @chip: a &struct tpm_chip instance, %NULL for the default chip + * @pcr_idx: the PCR to be reset + * + * Return: same as with tpm_transmit_cmd() + */ +int tpm_pcr_reset(struct tpm_chip *chip, u32 pcr_idx) +{ + int rc; + + chip = tpm_find_get_ops(chip); + if (!chip) + return -ENODEV; + + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + rc = tpm2_pcr_reset(chip, pcr_idx); + goto out; + } + + rc = tpm1_pcr_reset(chip, pcr_idx, "attempting to reset a PCR"); + +out: + tpm_put_ops(chip); + return rc; +} +EXPORT_SYMBOL_GPL(tpm_pcr_reset); + /** * tpm_send - send a TPM command * @chip: a &struct tpm_chip instance, %NULL for the default chip diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 2163c6ee0d364f..72b6c0873852c6 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -174,6 +174,7 @@ int tpm1_get_timeouts(struct tpm_chip *chip); unsigned long tpm1_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal); int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash, const char *log_msg); +int tpm1_pcr_reset(struct tpm_chip *chip, u32 pcr_idx, const char *log_msg); int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf); ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap, const char *desc, size_t min_cap_length); @@ -216,6 +217,7 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digest, u16 *digest_size_ptr); int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digests); +int tpm2_pcr_reset(struct tpm_chip *chip, u32 pcr_idx); int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max); ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value, const char *desc); diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c index f7dc986fa4a0a2..9b9ad1fc20ccfd 100644 --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -478,6 +478,40 @@ int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash, return rc; } +struct tpm_pcr_selection { + u16 size_of_select; + u8 pcr_select[3]; +} __packed; + +#define TPM_ORD_PCR_RESET 200 +int tpm1_pcr_reset(struct tpm_chip *chip, u32 pcr_idx, const char *log_msg) +{ + struct tpm_pcr_selection selection; + struct tpm_buf buf; + int i, rc; + char tmp; + + rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_RESET); + if (rc) + return rc; + + selection.size_of_select = 3; + + for (i = 0; i < selection.size_of_select; i++) { + tmp = 0; + if (pcr_idx / 3 == i) { + pcr_idx -= i * 8; + tmp |= 1 << pcr_idx; + } + selection.pcr_select[i] = tmp; + } + tpm_buf_append(&buf, (u8 *)&selection, sizeof(selection)); + + rc = tpm_transmit_cmd(chip, &buf, sizeof(selection), log_msg); + tpm_buf_destroy(&buf); + return rc; +} + #define TPM_ORD_GET_CAP 101 ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap, const char *desc, size_t min_cap_length) diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 4704fa553098b5..c0806b4447c8b2 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -269,6 +269,42 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, return rc; } +/** + * tpm2_pcr_reset() - reset a PCR + * + * @chip: TPM chip to use. + * @pcr_idx: index of the PCR. + * + * Return: Same as with tpm_transmit_cmd. + */ +int tpm2_pcr_reset(struct tpm_chip *chip, u32 pcr_idx) +{ + struct tpm_buf buf; + struct tpm2_null_auth_area auth_area; + int rc; + + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_RESET); + if (rc) + return rc; + + tpm_buf_append_u32(&buf, pcr_idx); + + 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_u32(&buf, sizeof(struct tpm2_null_auth_area)); + tpm_buf_append(&buf, (const unsigned char *)&auth_area, + sizeof(auth_area)); + + rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to reset a PCR"); + + tpm_buf_destroy(&buf); + + return rc; +} + struct tpm2_get_random_out { __be16 size; u8 buffer[TPM_MAX_RNG_DATA]; diff --git a/include/linux/tpm.h b/include/linux/tpm.h index dfeb25a0362dee..8320cbac6f4009 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -219,6 +219,7 @@ enum tpm2_command_codes { TPM2_CC_HIERARCHY_CONTROL = 0x0121, TPM2_CC_HIERARCHY_CHANGE_AUTH = 0x0129, TPM2_CC_CREATE_PRIMARY = 0x0131, + TPM2_CC_PCR_RESET = 0x013D, TPM2_CC_SEQUENCE_COMPLETE = 0x013E, TPM2_CC_SELF_TEST = 0x0143, TPM2_CC_STARTUP = 0x0144, @@ -423,6 +424,7 @@ extern ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf, size_t min_rsp_body_length, const char *desc); extern int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digest); +extern int tpm_pcr_reset(struct tpm_chip *chip, u32 pcr_idx); extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digests); extern int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen); @@ -440,6 +442,11 @@ static inline int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, return -ENODEV; } +static inline int tpm_pcr_reset(struct tpm_chip *chip, int pcr_idx) +{ + return -ENODEV; +} + static inline int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digests) {