On Wed, Jan 11, 2017 at 02:54:22AM -0500, Nayna Jain wrote:
> Unlike the device driver support for TPM 1.2, the TPM 2.0 does
> not support the securityfs pseudo files for displaying the
> firmware event log.
>
> This patch enables support for providing the TPM 2.0 event log in
> binary form. TPM 2.0 event log supports a crypto agile format that
> records multiple digests, which is different from TPM 1.2. This
> patch enables the tpm_bios_log_setup for TPM 2.0 and adds the
> event log parser which understand the TPM 2.0 crypto agile format.
>
> Signed-off-by: Nayna Jain <na...@linux.vnet.ibm.com>
Overally looks good but I cannot test this.
/Jarkko
> ---
> drivers/char/tpm/Makefile | 2 +-
> .../char/tpm/{tpm_eventlog.c => tpm1_eventlog.c} | 35 ++--
> drivers/char/tpm/tpm2_eventlog.c | 203
> +++++++++++++++++++++
> drivers/char/tpm/tpm_acpi.c | 3 +
> drivers/char/tpm/tpm_eventlog.h | 63 +++++++
> 5 files changed, 291 insertions(+), 15 deletions(-)
> rename drivers/char/tpm/{tpm_eventlog.c => tpm1_eventlog.c} (95%)
> create mode 100644 drivers/char/tpm/tpm2_eventlog.c
>
> diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
> index a05b1eb..3d386a8 100644
> --- a/drivers/char/tpm/Makefile
> +++ b/drivers/char/tpm/Makefile
> @@ -3,7 +3,7 @@
> #
> obj-$(CONFIG_TCG_TPM) += tpm.o
> tpm-y := tpm-interface.o tpm-dev.o tpm-sysfs.o tpm-chip.o tpm2-cmd.o \
> - tpm_eventlog.o
> + tpm1_eventlog.o tpm2_eventlog.o
> tpm-$(CONFIG_ACPI) += tpm_ppi.o tpm_acpi.o
> tpm-$(CONFIG_OF) += tpm_of.o
> obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o
> diff --git a/drivers/char/tpm/tpm_eventlog.c
> b/drivers/char/tpm/tpm1_eventlog.c
> similarity index 95%
> rename from drivers/char/tpm/tpm_eventlog.c
> rename to drivers/char/tpm/tpm1_eventlog.c
> index 11bb113..9a8605e 100644
> --- a/drivers/char/tpm/tpm_eventlog.c
> +++ b/drivers/char/tpm/tpm1_eventlog.c
> @@ -390,9 +390,6 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
> unsigned int cnt;
> int rc = 0;
>
> - if (chip->flags & TPM_CHIP_FLAG_TPM2)
> - return 0;
> -
> rc = tpm_read_log(chip);
> if (rc)
> return rc;
> @@ -407,7 +404,13 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
> cnt++;
>
> chip->bin_log_seqops.chip = chip;
> - chip->bin_log_seqops.seqops = &tpm_binary_b_measurements_seqops;
> + if (chip->flags & TPM_CHIP_FLAG_TPM2)
> + chip->bin_log_seqops.seqops =
> + &tpm2_binary_b_measurements_seqops;
> + else
> + chip->bin_log_seqops.seqops =
> + &tpm_binary_b_measurements_seqops;
> +
>
> chip->bios_dir[cnt] =
> securityfs_create_file("binary_bios_measurements",
> @@ -418,17 +421,21 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
> goto err;
> cnt++;
>
> - chip->ascii_log_seqops.chip = chip;
> - chip->ascii_log_seqops.seqops = &tpm_ascii_b_measurements_seqops;
> + if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
>
> - chip->bios_dir[cnt] =
> - securityfs_create_file("ascii_bios_measurements",
> - 0440, chip->bios_dir[0],
> - (void *)&chip->ascii_log_seqops,
> - &tpm_bios_measurements_ops);
> - if (IS_ERR(chip->bios_dir[cnt]))
> - goto err;
> - cnt++;
> + chip->ascii_log_seqops.chip = chip;
> + chip->ascii_log_seqops.seqops =
> + &tpm_ascii_b_measurements_seqops;
> +
> + chip->bios_dir[cnt] =
> + securityfs_create_file("ascii_bios_measurements",
> + 0440, chip->bios_dir[0],
> + (void *)&chip->ascii_log_seqops,
> + &tpm_bios_measurements_ops);
> + if (IS_ERR(chip->bios_dir[cnt]))
> + goto err;
> + cnt++;
> + }
>
> return 0;
>
> diff --git a/drivers/char/tpm/tpm2_eventlog.c
> b/drivers/char/tpm/tpm2_eventlog.c
> new file mode 100644
> index 0000000..1063b09
> --- /dev/null
> +++ b/drivers/char/tpm/tpm2_eventlog.c
> @@ -0,0 +1,203 @@
> +/*
> + * Copyright (C) 2016 IBM Corporation
> + *
> + * Authors:
> + * Nayna Jain <na...@linux.vnet.ibm.com>
> + *
> + * Access to TPM 2.0 event log as written by Firmware.
> + * It assumes that writer of event log has followed TCG Specification
> + * for Family "2.0" and written the event data in little endian.
> + * With that, it doesn't need any endian conversion for structure
> + * content.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version
> + * 2 of the License, or (at your option) any later version.
> + */
> +
> +#include <linux/seq_file.h>
> +#include <linux/fs.h>
> +#include <linux/security.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +
> +#include "tpm.h"
> +#include "tpm_eventlog.h"
> +
> +/*
> + * calc_tpm2_event_size() - calculate the event size, where event
> + * is an entry in the TPM 2.0 event log. The event is of type Crypto
> + * Agile Log Entry Format as defined in TCG EFI Protocol Specification
> + * Family "2.0".
> +
> + * @event: event whose size is to be calculated.
> + * @event_header: the first event in the event log.
> + *
> + * Returns size of the event. If it is an invalid event, returns 0.
> + */
> +static int calc_tpm2_event_size(struct tcg_pcr_event2 *event,
> + struct tcg_pcr_event *event_header)
> +{
> + struct tcg_efi_specid_event *efispecid;
> + struct tcg_event_field *event_field;
> + void *marker;
> + void *marker_start;
> + u32 halg_size;
> + size_t size;
> + u16 halg;
> + int i;
> + int j;
> +
> + marker = event;
> + marker_start = marker;
> + marker = marker + sizeof(event->pcr_idx) + sizeof(event->event_type)
> + + sizeof(event->digests.count);
> +
> + efispecid = (struct tcg_efi_specid_event *)event_header->event;
> +
> + for (i = 0; (i < event->digests.count) && (i < TPM2_ACTIVE_PCR_BANKS);
> + i++) {
> + halg_size = sizeof(event->digests.digests[i].alg_id);
> + memcpy(&halg, marker, halg_size);
> + marker = marker + halg_size;
> + for (j = 0; (j < efispecid->num_algs); j++) {
> + if (halg == efispecid->digest_sizes[j].alg_id) {
> + marker = marker +
> + efispecid->digest_sizes[j].digest_size;
> + break;
> + }
> + }
> + }
> +
> + event_field = (struct tcg_event_field *)marker;
> + marker = marker + sizeof(event_field->event_size)
> + + event_field->event_size;
> + size = marker - marker_start;
> +
> + if ((event->event_type == 0) && (event_field->event_size == 0))
> + return 0;
> +
> + return size;
> +}
> +
> +static void *tpm2_bios_measurements_start(struct seq_file *m, loff_t *pos)
> +{
> + struct tpm_chip *chip = m->private;
> + struct tpm_bios_log *log = &chip->log;
> + void *addr = log->bios_event_log;
> + void *limit = log->bios_event_log_end;
> + struct tcg_pcr_event *event_header;
> + struct tcg_pcr_event2 *event;
> + size_t size;
> + int i;
> +
> + event_header = addr;
> + size = sizeof(struct tcg_pcr_event) - sizeof(event_header->event)
> + + event_header->event_size;
> +
> + if (*pos == 0) {
> + if (addr + size < limit) {
> + if ((event_header->event_type == 0) &&
> + (event_header->event_size == 0))
> + return NULL;
> + return SEQ_START_TOKEN;
> + }
> + }
> +
> + if (*pos > 0) {
> + addr += size;
> + event = addr;
> + size = calc_tpm2_event_size(event, event_header);
> + if ((addr + size >= limit) || (size == 0))
> + return NULL;
> + }
> +
> + for (i = 0; i < (*pos - 1); i++) {
> + event = addr;
> + size = calc_tpm2_event_size(event, event_header);
> +
> + if ((addr + size >= limit) || (size == 0))
> + return NULL;
> + addr += size;
> + }
> +
> + return addr;
> +}
> +
> +static void *tpm2_bios_measurements_next(struct seq_file *m, void *v,
> + loff_t *pos)
> +{
> + struct tcg_pcr_event *event_header;
> + struct tcg_pcr_event2 *event;
> + struct tpm_chip *chip = m->private;
> + struct tpm_bios_log *log = &chip->log;
> + void *limit = log->bios_event_log_end;
> + size_t event_size;
> + void *marker;
> +
> + event_header = log->bios_event_log;
> +
> + if (v == SEQ_START_TOKEN) {
> + event_size = sizeof(struct tcg_pcr_event) -
> + sizeof(event_header->event) + event_header->event_size;
> + marker = event_header;
> + } else {
> + event = v;
> + event_size = calc_tpm2_event_size(event, event_header);
> + if (event_size == 0)
> + return NULL;
> + marker = event;
> + }
> +
> + marker = marker + event_size;
> + if (marker >= limit)
> + return NULL;
> + v = marker;
> + event = v;
> +
> + event_size = calc_tpm2_event_size(event, event_header);
> + if (((v + event_size) >= limit) || (event_size == 0))
> + return NULL;
> +
> + (*pos)++;
> + return v;
> +}
> +
> +static void tpm2_bios_measurements_stop(struct seq_file *m, void *v)
> +{
> +}
> +
> +static int tpm2_binary_bios_measurements_show(struct seq_file *m, void *v)
> +{
> + struct tpm_chip *chip = m->private;
> + struct tpm_bios_log *log = &chip->log;
> + struct tcg_pcr_event *event_header = log->bios_event_log;
> + struct tcg_pcr_event2 *event = v;
> + void *temp_ptr;
> + size_t size;
> +
> + if (v == SEQ_START_TOKEN) {
> + size = sizeof(struct tcg_pcr_event) -
> + sizeof(event_header->event) + event_header->event_size;
> +
> + temp_ptr = event_header;
> +
> + if (size > 0)
> + seq_write(m, temp_ptr, size);
> + } else {
> + size = calc_tpm2_event_size(event, event_header);
> + temp_ptr = event;
> + if (size > 0)
> + seq_write(m, temp_ptr, size);
> + }
> +
> + return 0;
> +}
> +
> +const struct seq_operations tpm2_binary_b_measurements_seqops = {
> + .start = tpm2_bios_measurements_start,
> + .next = tpm2_bios_measurements_next,
> + .stop = tpm2_bios_measurements_stop,
> + .show = tpm2_binary_bios_measurements_show,
> +};
> diff --git a/drivers/char/tpm/tpm_acpi.c b/drivers/char/tpm/tpm_acpi.c
> index b7718c9..169edf3 100644
> --- a/drivers/char/tpm/tpm_acpi.c
> +++ b/drivers/char/tpm/tpm_acpi.c
> @@ -54,6 +54,9 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
> u64 len, start;
> struct tpm_bios_log *log;
>
> + if (chip->flags & TPM_CHIP_FLAG_TPM2)
> + return -ENODEV;
> +
> log = &chip->log;
>
> /* Unfortuntely ACPI does not associate the event log with a specific
> diff --git a/drivers/char/tpm/tpm_eventlog.h b/drivers/char/tpm/tpm_eventlog.h
> index 1660d74..67c507f 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 <crypto/hash_info.h>
> +
> #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 +76,66 @@ enum tcpa_pc_event_ids {
> HOST_TABLE_OF_DEVICES,
> };
>
> +/*
> + * All the structures related to TPM 2.0 Event Log are taken from TCG EFI
> + * Protocol Specification, Family "2.0". Document is available on link
> + * http://www.trustedcomputinggroup.org/tcg-efi-protocol-specification/ .
> + * Information is also available on TCG PC Client Platform Firmware Profile
> + * Specification, Family "2.0".
> + * Detailed digest structures for TPM 2.0 are defined in document
> + * Trusted Platform Module Library Part 2: Structures, Family "2.0".
> + */
> +
> +struct tcg_efi_specid_event_algs {
> + u16 alg_id;
> + u16 digest_size;
> +} __packed;
> +
> +struct tcg_efi_specid_event {
> + u8 signature[16];
> + u32 platform_class;
> + u8 spec_version_minor;
> + u8 spec_version_major;
> + u8 spec_errata;
> + u8 uintnsize;
> + u32 num_algs;
> + struct tcg_efi_specid_event_algs digest_sizes[TPM2_ACTIVE_PCR_BANKS];
> + u8 vendor_info_size;
> + u8 vendor_info[0];
> +} __packed;
> +
> +struct tcg_pcr_event {
> + u32 pcr_idx;
> + u32 event_type;
> + u8 digest[20];
> + u32 event_size;
> + u8 event[0];
> +} __packed;
> +
> +struct tpmt_ha {
> + u16 alg_id;
> + u8 digest[SHA384_DIGEST_SIZE];
> +} __packed;
> +
> +struct tpml_digest_values {
> + u32 count;
> + struct tpmt_ha digests[TPM2_ACTIVE_PCR_BANKS];
> +} __packed;
> +
> +struct tcg_event_field {
> + u32 event_size;
> + u8 event[0];
> +} __packed;
> +
> +struct tcg_pcr_event2 {
> + u32 pcr_idx;
> + u32 event_type;
> + struct tpml_digest_values digests;
> + struct tcg_event_field event;
> +} __packed;
> +
> +extern const struct seq_operations tpm2_binary_b_measurements_seqops;
> +
> #if defined(CONFIG_ACPI)
> int tpm_read_log_acpi(struct tpm_chip *chip);
> #else
> --
> 2.5.0
>
