mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![Matthew Garrett](/assets/img/avatar_default.png)
UEFI systems provide a boot services protocol for obtaining the TPM event log, but this is unusable after ExitBootServices() is called. Unfortunately ExitBootServices() itself triggers additional TPM events that then can't be obtained using this protocol. The platform provides a mechanism for the OS to obtain these events by recording them to a separate UEFI configuration table which the OS can then map. Unfortunately this table isn't self describing in terms of providing its length, so we need to parse the events inside it to figure out how long it is. Since the table isn't mapped at this point, we need to extend the length calculation function to be able to map the event as it goes along. (Fixes by Bartosz Szczepanek <bsz@semihalf.com>) Signed-off-by: Matthew Garrett <mjg59@google.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Bartosz Szczepanek <bsz@semihalf.com> Tested-by: Bartosz Szczepanek <bsz@semihalf.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
267 lines
5.6 KiB
C
267 lines
5.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
|
|
#ifndef __LINUX_TPM_EVENTLOG_H__
|
|
#define __LINUX_TPM_EVENTLOG_H__
|
|
|
|
#include <linux/tpm.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 EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2 0x1
|
|
#define EFI_TCG2_EVENT_LOG_FORMAT_TCG_2 0x2
|
|
|
|
#ifdef CONFIG_PPC64
|
|
#define do_endian_conversion(x) be32_to_cpu(x)
|
|
#else
|
|
#define do_endian_conversion(x) x
|
|
#endif
|
|
|
|
enum bios_platform_class {
|
|
BIOS_CLIENT = 0x00,
|
|
BIOS_SERVER = 0x01,
|
|
};
|
|
|
|
struct tcpa_event {
|
|
u32 pcr_index;
|
|
u32 event_type;
|
|
u8 pcr_value[20]; /* SHA1 */
|
|
u32 event_size;
|
|
u8 event_data[0];
|
|
};
|
|
|
|
enum tcpa_event_types {
|
|
PREBOOT = 0,
|
|
POST_CODE,
|
|
UNUSED,
|
|
NO_ACTION,
|
|
SEPARATOR,
|
|
ACTION,
|
|
EVENT_TAG,
|
|
SCRTM_CONTENTS,
|
|
SCRTM_VERSION,
|
|
CPU_MICROCODE,
|
|
PLATFORM_CONFIG_FLAGS,
|
|
TABLE_OF_DEVICES,
|
|
COMPACT_HASH,
|
|
IPL,
|
|
IPL_PARTITION_DATA,
|
|
NONHOST_CODE,
|
|
NONHOST_CONFIG,
|
|
NONHOST_INFO,
|
|
};
|
|
|
|
struct tcpa_pc_event {
|
|
u32 event_id;
|
|
u32 event_size;
|
|
u8 event_data[0];
|
|
};
|
|
|
|
enum tcpa_pc_event_ids {
|
|
SMBIOS = 1,
|
|
BIS_CERT,
|
|
POST_BIOS_ROM,
|
|
ESCD,
|
|
CMOS,
|
|
NVRAM,
|
|
OPTION_ROM_EXEC,
|
|
OPTION_ROM_CONFIG,
|
|
OPTION_ROM_MICROCODE = 10,
|
|
S_CRTM_VERSION,
|
|
S_CRTM_CONTENTS,
|
|
POST_CONTENTS,
|
|
HOST_TABLE_OF_DEVICES,
|
|
};
|
|
|
|
/* http://www.trustedcomputinggroup.org/tcg-efi-protocol-specification/ */
|
|
|
|
struct tcg_efi_specid_event_algs {
|
|
u16 alg_id;
|
|
u16 digest_size;
|
|
} __packed;
|
|
|
|
struct tcg_efi_specid_event_head {
|
|
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[];
|
|
} __packed;
|
|
|
|
struct tcg_pcr_event {
|
|
u32 pcr_idx;
|
|
u32 event_type;
|
|
u8 digest[20];
|
|
u32 event_size;
|
|
u8 event[0];
|
|
} __packed;
|
|
|
|
struct tcg_event_field {
|
|
u32 event_size;
|
|
u8 event[0];
|
|
} __packed;
|
|
|
|
struct tcg_pcr_event2_head {
|
|
u32 pcr_idx;
|
|
u32 event_type;
|
|
u32 count;
|
|
struct tpm_digest digests[];
|
|
} __packed;
|
|
|
|
struct tcg_algorithm_size {
|
|
u16 algorithm_id;
|
|
u16 algorithm_size;
|
|
};
|
|
|
|
struct tcg_algorithm_info {
|
|
u8 signature[16];
|
|
u32 platform_class;
|
|
u8 spec_version_minor;
|
|
u8 spec_version_major;
|
|
u8 spec_errata;
|
|
u8 uintn_size;
|
|
u32 number_of_algorithms;
|
|
struct tcg_algorithm_size digest_sizes[];
|
|
};
|
|
|
|
#ifndef TPM_MEMREMAP
|
|
#define TPM_MEMREMAP(start, size) NULL
|
|
#endif
|
|
|
|
#ifndef TPM_MEMUNMAP
|
|
#define TPM_MEMUNMAP(start, size) do{} while(0)
|
|
#endif
|
|
|
|
/**
|
|
* __calc_tpm2_event_size - calculate the size of a TPM2 event log entry
|
|
* @event: Pointer to the event whose size should be calculated
|
|
* @event_header: Pointer to the initial event containing the digest lengths
|
|
* @do_mapping: Whether or not the event needs to be mapped
|
|
*
|
|
* The TPM2 event log format can contain multiple digests corresponding to
|
|
* separate PCR banks, and also contains a variable length of the data that
|
|
* was measured. This requires knowledge of how long each digest type is,
|
|
* and this information is contained within the first event in the log.
|
|
*
|
|
* We calculate the length by examining the number of events, and then looking
|
|
* at each event in turn to determine how much space is used for events in
|
|
* total. Once we've done this we know the offset of the data length field,
|
|
* and can calculate the total size of the event.
|
|
*
|
|
* Return: size of the event on success, <0 on failure
|
|
*/
|
|
|
|
static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event,
|
|
struct tcg_pcr_event *event_header,
|
|
bool do_mapping)
|
|
{
|
|
struct tcg_efi_specid_event_head *efispecid;
|
|
struct tcg_event_field *event_field;
|
|
void *mapping = NULL;
|
|
int mapping_size;
|
|
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->count);
|
|
|
|
/* Map the event header */
|
|
if (do_mapping) {
|
|
mapping_size = marker - marker_start;
|
|
mapping = TPM_MEMREMAP((unsigned long)marker_start,
|
|
mapping_size);
|
|
if (!mapping) {
|
|
size = 0;
|
|
goto out;
|
|
}
|
|
} else {
|
|
mapping = marker_start;
|
|
}
|
|
|
|
event = (struct tcg_pcr_event2_head *)mapping;
|
|
|
|
efispecid = (struct tcg_efi_specid_event_head *)event_header->event;
|
|
|
|
/* Check if event is malformed. */
|
|
if (event->count > efispecid->num_algs) {
|
|
size = 0;
|
|
goto out;
|
|
}
|
|
|
|
for (i = 0; i < event->count; i++) {
|
|
halg_size = sizeof(event->digests[i].alg_id);
|
|
|
|
/* Map the digest's algorithm identifier */
|
|
if (do_mapping) {
|
|
TPM_MEMUNMAP(mapping, mapping_size);
|
|
mapping_size = halg_size;
|
|
mapping = TPM_MEMREMAP((unsigned long)marker,
|
|
mapping_size);
|
|
if (!mapping) {
|
|
size = 0;
|
|
goto out;
|
|
}
|
|
} else {
|
|
mapping = marker;
|
|
}
|
|
|
|
memcpy(&halg, mapping, halg_size);
|
|
marker = marker + halg_size;
|
|
|
|
for (j = 0; j < efispecid->num_algs; j++) {
|
|
if (halg == efispecid->digest_sizes[j].alg_id) {
|
|
marker +=
|
|
efispecid->digest_sizes[j].digest_size;
|
|
break;
|
|
}
|
|
}
|
|
/* Algorithm without known length. Such event is unparseable. */
|
|
if (j == efispecid->num_algs) {
|
|
size = 0;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Map the event size - we don't read from the event itself, so
|
|
* we don't need to map it
|
|
*/
|
|
if (do_mapping) {
|
|
TPM_MEMUNMAP(mapping, mapping_size);
|
|
mapping_size += sizeof(event_field->event_size);
|
|
mapping = TPM_MEMREMAP((unsigned long)marker,
|
|
mapping_size);
|
|
if (!mapping) {
|
|
size = 0;
|
|
goto out;
|
|
}
|
|
} else {
|
|
mapping = marker;
|
|
}
|
|
|
|
event_field = (struct tcg_event_field *)mapping;
|
|
|
|
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))
|
|
size = 0;
|
|
out:
|
|
if (do_mapping)
|
|
TPM_MEMUNMAP(mapping, mapping_size);
|
|
return size;
|
|
}
|
|
|
|
#endif
|