Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754398AbcL3TCy (ORCPT ); Fri, 30 Dec 2016 14:02:54 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:40150 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753414AbcL3TCv (ORCPT ); Fri, 30 Dec 2016 14:02:51 -0500 From: Nayna Jain To: tpmdd-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Cc: peterhuewe@gmx.de, tpmdd@selhorst.net, jarkko.sakkinen@linux.intel.com, jgunthorpe@obsidianresearch.com, Nayna Jain Subject: [PATCH v2 2/2] tpm: enhance TPM 2.0 PCR extend to support multiple banks Date: Fri, 30 Dec 2016 14:02:30 -0500 X-Mailer: git-send-email 2.5.0 In-Reply-To: <1483124550-9529-1-git-send-email-nayna@linux.vnet.ibm.com> References: <1483124550-9529-1-git-send-email-nayna@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16123019-0044-0000-0000-0000021776E5 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16123019-0045-0000-0000-000006451410 Message-Id: <1483124550-9529-3-git-send-email-nayna@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-12-30_14:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=9 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1612300297 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6901 Lines: 211 The current TPM 2.0 device driver extends only the SHA1 PCR bank but the TCG Specification[1] recommends extending all active PCR banks, to prevent malicious users from setting unused PCR banks with fake measurements and quoting them. The existing in-kernel interface(tpm_pcr_extend()) expects only a SHA1 digest. To extend all active PCR banks with differing digest sizes, the SHA1 digest is padded with trailing 0's as needed. [1] TPM 2.0 Specification referred here is "TCG PC Client Specific Platform Firmware Profile for TPM 2.0" Signed-off-by: Nayna Jain --- drivers/char/tpm/tpm-interface.c | 16 +++++++++- drivers/char/tpm/tpm.h | 3 +- drivers/char/tpm/tpm2-cmd.c | 67 ++++++++++++++++++++++------------------ drivers/char/tpm/tpm_eventlog.h | 15 +++++++++ 4 files changed, 69 insertions(+), 32 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 769d8b0..04aee1c 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -7,6 +7,7 @@ * Dave Safford * Reiner Sailer * Kylene Hall + * Nayna Jain * * Maintained by: * @@ -756,6 +757,7 @@ static const struct tpm_input_header pcrextend_header = { int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash) { struct tpm_cmd_t cmd; + int i; int rc; struct tpm_chip *chip; @@ -764,7 +766,19 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash) return -ENODEV; if (chip->flags & TPM_CHIP_FLAG_TPM2) { - rc = tpm2_pcr_extend(chip, pcr_idx, hash); + struct tpml_digest_values d_values; + + memset(&d_values, 0, sizeof(d_values)); + + for (i = 0; (chip->active_banks[i] != 0) && + (i < TPM2_MAX_PCR_BANKS); i++) { + d_values.digests[i].alg_id = chip->active_banks[i]; + memcpy(d_values.digests[i].digest, hash, + TPM_DIGEST_SIZE); + d_values.count++; + } + + rc = tpm2_pcr_extend(chip, pcr_idx, &d_values); tpm_put_ops(chip); return rc; } diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 3d8121e..1d44a52 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -534,7 +534,8 @@ static inline void tpm_add_ppi(struct tpm_chip *chip) #endif int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf); -int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash); +int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, + struct tpml_digest_values *digests); int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max); int tpm2_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload, diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index dd03fd8..93d07bf 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -64,9 +64,7 @@ struct tpm2_pcr_extend_in { __be32 pcr_idx; __be32 auth_area_size; struct tpm2_null_auth_area auth_area; - __be32 digest_cnt; - __be16 hash_alg; - u8 digest[TPM_DIGEST_SIZE]; + struct tpml_digest_values digests; } __packed; struct tpm2_get_tpm_pt_in { @@ -311,46 +309,55 @@ int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf) return rc; } -#define TPM2_GET_PCREXTEND_IN_SIZE \ - (sizeof(struct tpm_input_header) + \ - sizeof(struct tpm2_pcr_extend_in)) - -static const struct tpm_input_header tpm2_pcrextend_header = { - .tag = cpu_to_be16(TPM2_ST_SESSIONS), - .length = cpu_to_be32(TPM2_GET_PCREXTEND_IN_SIZE), - .ordinal = cpu_to_be32(TPM2_CC_PCR_EXTEND) -}; - /** * tpm2_pcr_extend() - extend a PCR value * * @chip: TPM chip to use. * @pcr_idx: index of the PCR. - * @hash: hash value to use for the extend operation. + * @digests: list of pcr banks and corresponding hash values to be extended. * * Return: Same as with tpm_transmit_cmd. */ -int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash) +int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, + struct tpml_digest_values *digests) { - struct tpm2_cmd cmd; + struct tpm_buf buf; + struct tpm2_null_auth_area auth_area; int rc; + int i; + int j; + + tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND); + 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)); + tpm_buf_append_u32(&buf, digests->count); + + for (i = 0; i < digests->count; i++) { + for (j = 0; j < ARRAY_SIZE(tpm2_hash_map); j++) { + if (digests->digests[i].alg_id != + tpm2_hash_map[j].tpm_id) + continue; + + tpm_buf_append_u16(&buf, digests->digests[i].alg_id); + tpm_buf_append(&buf, (const unsigned char + *)&digests->digests[i].digest, + hash_digest_size[tpm2_hash_map[j].crypto_id]); + } + } - cmd.header.in = tpm2_pcrextend_header; - cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx); - cmd.params.pcrextend_in.auth_area_size = - cpu_to_be32(sizeof(struct tpm2_null_auth_area)); - cmd.params.pcrextend_in.auth_area.handle = - cpu_to_be32(TPM2_RS_PW); - cmd.params.pcrextend_in.auth_area.nonce_size = 0; - cmd.params.pcrextend_in.auth_area.attributes = 0; - cmd.params.pcrextend_in.auth_area.auth_size = 0; - cmd.params.pcrextend_in.digest_cnt = cpu_to_be32(1); - cmd.params.pcrextend_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1); - memcpy(cmd.params.pcrextend_in.digest, hash, TPM_DIGEST_SIZE); - - rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, + rc = tpm_transmit_cmd(chip, buf.data, tpm_buf_length(&buf), 0, "attempting extend a PCR value"); + tpm_buf_destroy(&buf); + return rc; } diff --git a/drivers/char/tpm/tpm_eventlog.h b/drivers/char/tpm/tpm_eventlog.h index 1660d74..7d97b51 100644 --- a/drivers/char/tpm/tpm_eventlog.h +++ b/drivers/char/tpm/tpm_eventlog.h @@ -2,9 +2,12 @@ #ifndef __TPM_EVENTLOG_H__ #define __TPM_EVENTLOG_H__ +#include + #define TCG_EVENT_NAME_LEN_MAX 255 #define MAX_TEXT_EVENT 1000 /* Max event string length */ #define ACPI_TCPA_SIG "TCPA" /* 0x41504354 /'TCPA' */ +#define TPM2_ACTIVE_PCR_BANKS 3 #ifdef CONFIG_PPC64 #define do_endian_conversion(x) be32_to_cpu(x) @@ -73,6 +76,18 @@ enum tcpa_pc_event_ids { HOST_TABLE_OF_DEVICES, }; +/* TPM 2.0 Crypto agile algorithm and respective digest. */ +struct tpmt_ha { + u16 alg_id; + u8 digest[SHA384_DIGEST_SIZE]; +} __packed; + +/* TPM 2.0 Crypto agile digests list. */ +struct tpml_digest_values { + u32 count; + struct tpmt_ha digests[TPM2_ACTIVE_PCR_BANKS]; +} __packed; + #if defined(CONFIG_ACPI) int tpm_read_log_acpi(struct tpm_chip *chip); #else -- 2.5.0