From patchwork Tue Dec 4 08:21:36 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 10711279 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E58AF16B1 for ; Tue, 4 Dec 2018 08:27:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D7B2D28CBC for ; Tue, 4 Dec 2018 08:27:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C86D52ABFA; Tue, 4 Dec 2018 08:27:08 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0A7FD28CBC for ; Tue, 4 Dec 2018 08:27:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725996AbeLDI1H (ORCPT ); Tue, 4 Dec 2018 03:27:07 -0500 Received: from lhrrgout.huawei.com ([185.176.76.210]:32795 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725983AbeLDI1H (ORCPT ); Tue, 4 Dec 2018 03:27:07 -0500 Received: from lhreml701-cah.china.huawei.com (unknown [172.18.7.108]) by Forcepoint Email with ESMTP id A2E18FBCCA0A8; Tue, 4 Dec 2018 08:27:03 +0000 (GMT) Received: from roberto-HP-EliteDesk-800-G2-DM-65W.huawei.com (10.204.65.153) by smtpsuk.huawei.com (10.201.108.42) with Microsoft SMTP Server (TLS) id 14.3.408.0; Tue, 4 Dec 2018 08:26:57 +0000 From: Roberto Sassu To: , , , CC: , , , , Roberto Sassu Subject: [PATCH v6 5/7] tpm: retrieve digest size of unknown algorithms with PCR read Date: Tue, 4 Dec 2018 09:21:36 +0100 Message-ID: <20181204082138.24600-6-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181204082138.24600-1-roberto.sassu@huawei.com> References: <20181204082138.24600-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.65.153] X-CFilter-Loop: Reflected Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP Currently, the TPM driver retrieves the digest size from a table mapping TPM algorithms identifiers to identifiers defined by the crypto subsystem. If the algorithm is not defined by the latter, the digest size can be retrieved from the output of the PCR read command. The patch retrieves at TPM startup the digest sizes for each PCR bank and stores them in the new structure tpm_bank_info, member of tpm_chip, so that the information can be passed to other kernel subsystems. tpm_bank_info contains: the TPM algorithm identifier, necessary to generate the event log as defined by Trusted Computing Group (TCG); the digest size, to pad/truncate a digest calculated with a different algorithm; the crypto subsystem identifier, to calculate the digest of event data. Signed-off-by: Roberto Sassu Reviewed-by: Jarkko Sakkinen Acked-by: Mimi Zohar --- drivers/char/tpm/tpm-interface.c | 9 +++---- drivers/char/tpm/tpm.h | 4 +-- drivers/char/tpm/tpm1-cmd.c | 4 ++- drivers/char/tpm/tpm2-cmd.c | 45 ++++++++++++++++++++++++-------- include/linux/tpm.h | 6 +++++ 5 files changed, 49 insertions(+), 19 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index cea4c8d75ad0..eb7c79ca8a94 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -465,7 +465,7 @@ int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, return -ENODEV; if (chip->flags & TPM_CHIP_FLAG_TPM2) - rc = tpm2_pcr_read(chip, pcr_idx, digest); + rc = tpm2_pcr_read(chip, pcr_idx, digest, NULL); else rc = tpm1_pcr_read(chip, pcr_idx, digest->digest); @@ -480,9 +480,8 @@ EXPORT_SYMBOL_GPL(tpm_pcr_read); * @pcr_idx: the PCR to be retrieved * @hash: the hash value used to extend the PCR value * - * Note: with TPM 2.0 extends also those banks with a known digest size to the - * cryto subsystem in order to prevent malicious use of those PCR banks. In the - * future we should dynamically determine digest sizes. + * Note: with TPM 2.0 extends also those banks for which no digest was + * specified in order to prevent malicious use of those PCR banks. * * Return: same as with tpm_transmit_cmd() */ @@ -503,7 +502,7 @@ int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash) return -ENOMEM; for (i = 0; i < chip->nr_allocated_banks; i++) { - digest_list[i].alg_id = chip->allocated_banks[i]; + digest_list[i].alg_id = chip->allocated_banks[i].alg_id; memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE); } diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 343aa58424f7..64d93d26087f 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -247,7 +247,7 @@ struct tpm_chip { unsigned int groups_cnt; u32 nr_allocated_banks; - u16 *allocated_banks; + struct tpm_bank_info *allocated_banks; #ifdef CONFIG_ACPI acpi_handle acpi_dev_handle; char ppi_version[TPM_PPI_VERSION_LEN + 1]; @@ -549,7 +549,7 @@ static inline u32 tpm2_rc_value(u32 rc) int tpm2_get_timeouts(struct tpm_chip *chip); int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, - struct tpm_digest *digest); + struct tpm_digest *digest, u16 *digest_size_ptr); int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count, struct tpm_digest *digests); int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max); diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c index ec4f197bae0a..8b70a7f884a7 100644 --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -716,7 +716,9 @@ int tpm1_auto_startup(struct tpm_chip *chip) goto out; } - chip->allocated_banks[0] = TPM_ALG_SHA1; + chip->allocated_banks[0].alg_id = TPM_ALG_SHA1; + chip->allocated_banks[0].digest_size = hash_digest_size[HASH_ALGO_SHA1]; + chip->allocated_banks[0].crypto_id = HASH_ALGO_SHA1; chip->nr_allocated_banks = 1; return rc; diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 81740d55f19c..a804f0b7126a 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -172,11 +172,12 @@ struct tpm2_pcr_read_out { * @chip: TPM chip to use. * @pcr_idx: index of the PCR to read. * @digest: PCR bank and buffer current PCR value is written to. + * @digest_size_ptr: pointer to variable that stores the digest size. * * Return: Same as with tpm_transmit_cmd. */ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, - struct tpm_digest *digest) + struct tpm_digest *digest, u16 *digest_size_ptr) { int rc; struct tpm_buf buf; @@ -211,6 +212,9 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, goto out; } + if (digest_size_ptr) + *digest_size_ptr = digest_size; + memcpy(digest->digest, out->digest, digest_size); out: tpm_buf_destroy(&buf); @@ -241,7 +245,6 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count, struct tpm2_null_auth_area auth_area; int rc; int i; - int j; if (count > chip->nr_allocated_banks) return -EINVAL; @@ -263,14 +266,9 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count, tpm_buf_append_u32(&buf, count); for (i = 0; i < count; i++) { - for (j = 0; j < ARRAY_SIZE(tpm2_hash_map); j++) { - if (digests[i].alg_id != tpm2_hash_map[j].tpm_id) - continue; - tpm_buf_append_u16(&buf, digests[i].alg_id); - tpm_buf_append(&buf, (const unsigned char - *)&digests[i].digest, - hash_digest_size[tpm2_hash_map[j].crypto_id]); - } + tpm_buf_append_u16(&buf, digests[i].alg_id); + tpm_buf_append(&buf, (const unsigned char *)&digests[i].digest, + chip->allocated_banks[i].digest_size); } rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, @@ -821,6 +819,26 @@ int tpm2_probe(struct tpm_chip *chip) } EXPORT_SYMBOL_GPL(tpm2_probe); +static int tpm2_init_bank_info(struct tpm_chip *chip, u32 bank_index) +{ + struct tpm_bank_info *bank = chip->allocated_banks + bank_index; + struct tpm_digest digest = { .alg_id = bank->alg_id }; + int i; + + for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) { + enum hash_algo crypto_algo = tpm2_hash_map[i].crypto_id; + + if (bank->alg_id != tpm2_hash_map[i].tpm_id) + continue; + + bank->digest_size = hash_digest_size[crypto_algo]; + bank->crypto_id = crypto_algo; + return 0; + } + + return tpm2_pcr_read(chip, 0, &digest, &bank->digest_size); +} + struct tpm2_pcr_selection { __be16 hash_alg; u8 size_of_select; @@ -888,7 +906,12 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) break; if (j < pcr_selection.size_of_select) { - chip->allocated_banks[nr_alloc_banks] = hash_alg; + chip->allocated_banks[nr_alloc_banks].alg_id = hash_alg; + + rc = tpm2_init_bank_info(chip, nr_alloc_banks); + if (rc < 0) + break; + nr_alloc_banks++; } diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 95e11688826e..72df8d4252ef 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -46,6 +46,12 @@ struct tpm_digest { u8 digest[SHA512_DIGEST_SIZE]; } __packed; +struct tpm_bank_info { + u16 alg_id; + u16 digest_size; + u16 crypto_id; +}; + enum TPM_OPS_FLAGS { TPM_OPS_AUTO_STARTUP = BIT(0), };