From patchwork Sat Feb 20 01:32:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Garrett X-Patchwork-Id: 12096507 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2FDCEC433E6 for ; Sat, 20 Feb 2021 01:34:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 00A0E64EDE for ; Sat, 20 Feb 2021 01:34:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229884AbhBTBe2 (ORCPT ); Fri, 19 Feb 2021 20:34:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229771AbhBTBe1 (ORCPT ); Fri, 19 Feb 2021 20:34:27 -0500 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF0D8C061794 for ; Fri, 19 Feb 2021 17:33:09 -0800 (PST) Received: by mail-qt1-x84a.google.com with SMTP id d10so4441963qtx.8 for ; Fri, 19 Feb 2021 17:33:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=CtLRPHa6vVfWJfnUvKFAfqInMZ/2zkbzy/KaLuvq/RY=; b=np6G+qmB02m6CtsdX1J98BauvoCRqwR9uUAoQZ22HnNJ8AErOq7qAe01yv81qnazq7 7bmJqaZaEgG8ceyd+8a5WTsKEgcbxIK2fYrKz41nff+TJH3yWqdUMkWWFx62d5DLgJqZ n5/KdFSRNpxtx0Q+UEJQxrJfHUm3F4XGFEhSRwlZeLop/Ez9xYlluW4mTSJE8FE97q1v cosSPTLjucB4Jk1Cyy3x0f/w0r7Fv4vja9ht+0qyAIOFidMadt/oE6GmN2Wx24XSpQcx 62/kE5HdcY/YJL1Q5kiK5ftf3dCNwHukTsdRn8vzZZHFcU/3+A1jYEvb7iboCMpeH5L7 X+uQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=CtLRPHa6vVfWJfnUvKFAfqInMZ/2zkbzy/KaLuvq/RY=; b=lz8zfc9Wdi3prLa63ZaR/k/OvzL6KzBy1sQXk9cgvO3Jq/byC6/HinPkw8VSmpq+Q9 cohxywG50483vkBsg4u45e1IFd36AP861lLTwH+2i4aNtPrYxIdLg4rDOCajSZnqR92U WW49+bSzh5kTxomev066ZbxSs6S7XucVD1RSoLyxrRtXA0foKp72rpaR7vseFO19K/BF yy/ESGTg0C7MGuUu2j0Za8C5kHICWP6ffzkjhUhpvBT/5IZLbPT/aG7UMDS9WqJdLaHZ ICLjvFSKcXJyjRemL/GkF+vynWwTMvtmfQ8/t4aJB3+22UiywIj9RLcz6pzZhEq0UzVX wT7A== X-Gm-Message-State: AOAM531hzBabLBeQVQf5lgeQXL762fk9aEml3yDlvLvC40sOXPTOwCdV jGl00FvSd8a+qrHaS9RoFTOWP9KkpfBGaKntDK+QWQ== X-Google-Smtp-Source: ABdhPJxgycPtcGyLtpEWUmPPRqEvf5yxoDeFB4QBUiNxo/8m3G60P8mXpFrAXLh1D4foiHWOPPTgCdpjOwOooBtVjqzOIQ== Sender: "matthewgarrett via sendgmr" X-Received: from matthewgarrett-tmp.c.googlers.com ([fda3:e722:ac3:10:7f:e700:c0a8:1081]) (user=matthewgarrett job=sendgmr) by 2002:a0c:ac43:: with SMTP id m3mr12016912qvb.37.1613784787904; Fri, 19 Feb 2021 17:33:07 -0800 (PST) Date: Sat, 20 Feb 2021 01:32:47 +0000 In-Reply-To: <20210220013255.1083202-1-matthewgarrett@google.com> Message-Id: <20210220013255.1083202-2-matthewgarrett@google.com> Mime-Version: 1.0 References: <20210220013255.1083202-1-matthewgarrett@google.com> X-Mailer: git-send-email 2.30.0.617.g56c4b15f3c-goog Subject: [PATCH 1/9] tpm: Add support for in-kernel resetting of PCRs From: Matthew Garrett To: linux-kernel@vger.kernel.org Cc: linux-integrity@vger.kernel.org, linux-pm@vger.kernel.org, keyrings@vger.kernel.org, zohar@linux.ibm.com, jejb@linux.ibm.com, jarkko@kernel.org, corbet@lwn.net, rjw@rjwysocki.net, Matthew Garrett , Matthew Garrett Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Add an internal command for resetting a PCR. Signed-off-by: Matthew Garrett --- 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 1621ce818705..17b8643ee109 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 947d1db0a5cc..746f7696bdc0 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -176,6 +176,7 @@ 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); @@ -220,6 +221,7 @@ 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 ca7158fa6e6c..36990e9d2dc1 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 eff1f12d981a..9609ae8086c6 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 8f4ff39f51e7..e2075e2242a0 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -211,6 +211,7 @@ 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, @@ -399,6 +400,7 @@ static inline u32 tpm2_rc_value(u32 rc) extern int tpm_is_tpm2(struct tpm_chip *chip); 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); @@ -417,6 +419,11 @@ 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) {