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u-boot/lib/efi_loader/efi_tcg2.c
Simon Glass 156ccbc3c4 efi: Use 16-bit unicode strings 
At present we use wide characters for unicode but this is not necessary.
Change the code to use the 'u' literal instead. This helps to fix build
warnings for sandbox on rpi.

Signed-off-by: Simon Glass <sjg@chromium.org>
Suggested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2022-02-03 12:16:01 -05:00

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// SPDX-License-Identifier: GPL-2.0+
/*
* Defines APIs that allow an OS to interact with UEFI firmware to query
* information about the device.
* https://trustedcomputinggroup.org/resource/tcg-efi-protocol-specification/
*
* Copyright (c) 2020, Linaro Limited
*/
#define LOG_CATEGORY LOGC_EFI
#include <common.h>
#include <dm.h>
#include <efi_loader.h>
#include <efi_variable.h>
#include <efi_tcg2.h>
#include <log.h>
#include <malloc.h>
#include <smbios.h>
#include <version_string.h>
#include <tpm-v2.h>
#include <tpm_api.h>
#include <u-boot/hash-checksum.h>
#include <u-boot/sha1.h>
#include <u-boot/sha256.h>
#include <u-boot/sha512.h>
#include <linux/unaligned/be_byteshift.h>
#include <linux/unaligned/le_byteshift.h>
#include <linux/unaligned/generic.h>
#include <hexdump.h>
/**
* struct event_log_buffer - internal eventlog management structure
*
* @buffer: eventlog buffer
* @final_buffer: finalevent config table buffer
* @pos: current position of 'buffer'
* @final_pos: current position of 'final_buffer'
* @get_event_called: true if GetEventLog has been invoked at least once
* @ebs_called: true if ExitBootServices has been invoked
* @truncated: true if the 'buffer' is truncated
*/
struct event_log_buffer {
void *buffer;
void *final_buffer;
size_t pos; /* eventlog position */
size_t final_pos; /* final events config table position */
size_t last_event_size;
bool get_event_called;
bool ebs_called;
bool truncated;
};
static struct event_log_buffer event_log;
static bool tcg2_efi_app_invoked;
/*
* When requesting TPM2_CAP_TPM_PROPERTIES the value is on a standard offset.
* Since the current tpm2_get_capability() response buffers starts at
* 'union tpmu_capabilities data' of 'struct tpms_capability_data', calculate
* the response size and offset once for all consumers
*/
#define TPM2_RESPONSE_BUFFER_SIZE (sizeof(struct tpms_capability_data) - \
offsetof(struct tpms_capability_data, data))
#define properties_offset (offsetof(struct tpml_tagged_tpm_property, tpm_property) + \
offsetof(struct tpms_tagged_property, value))
static const efi_guid_t efi_guid_tcg2_protocol = EFI_TCG2_PROTOCOL_GUID;
static const efi_guid_t efi_guid_final_events = EFI_TCG2_FINAL_EVENTS_TABLE_GUID;
struct digest_info {
u16 hash_alg;
u32 hash_mask;
u16 hash_len;
};
static const struct digest_info hash_algo_list[] = {
{
TPM2_ALG_SHA1,
EFI_TCG2_BOOT_HASH_ALG_SHA1,
TPM2_SHA1_DIGEST_SIZE,
},
{
TPM2_ALG_SHA256,
EFI_TCG2_BOOT_HASH_ALG_SHA256,
TPM2_SHA256_DIGEST_SIZE,
},
{
TPM2_ALG_SHA384,
EFI_TCG2_BOOT_HASH_ALG_SHA384,
TPM2_SHA384_DIGEST_SIZE,
},
{
TPM2_ALG_SHA512,
EFI_TCG2_BOOT_HASH_ALG_SHA512,
TPM2_SHA512_DIGEST_SIZE,
},
};
struct variable_info {
const u16 *name;
bool accept_empty;
u32 pcr_index;
};
static struct variable_info secure_variables[] = {
{u"SecureBoot", true, 7},
{u"PK", true, 7},
{u"KEK", true, 7},
{u"db", true, 7},
{u"dbx", true, 7},
{u"dbt", false, 7},
{u"dbr", false, 7},
{u"DeployedMode", false, 1},
{u"AuditMode", false, 1},
};
#define MAX_HASH_COUNT ARRAY_SIZE(hash_algo_list)
/**
* alg_to_mask - Get a TCG hash mask for algorithms
*
* @hash_alg: TCG defined algorithm
*
* @Return: TCG hashing algorithm bitmaps, 0 if the algorithm is not supported
*/
static u32 alg_to_mask(u16 hash_alg)
{
size_t i;
for (i = 0; i < MAX_HASH_COUNT; i++) {
if (hash_algo_list[i].hash_alg == hash_alg)
return hash_algo_list[i].hash_mask;
}
return 0;
}
/**
* alg_to_len - Get a TCG hash len for algorithms
*
* @hash_alg: TCG defined algorithm
*
* @Return: len of chosen algorithm, 0 if the algorithm is not supported
*/
static u16 alg_to_len(u16 hash_alg)
{
size_t i;
for (i = 0; i < MAX_HASH_COUNT; i++) {
if (hash_algo_list[i].hash_alg == hash_alg)
return hash_algo_list[i].hash_len;
}
return 0;
}
static bool is_tcg2_protocol_installed(void)
{
struct efi_handler *handler;
efi_status_t ret;
ret = efi_search_protocol(efi_root, &efi_guid_tcg2_protocol, &handler);
return ret == EFI_SUCCESS;
}
static u32 tcg_event_final_size(struct tpml_digest_values *digest_list)
{
u32 len;
size_t i;
len = offsetof(struct tcg_pcr_event2, digests);
len += offsetof(struct tpml_digest_values, digests);
for (i = 0; i < digest_list->count; i++) {
u16 hash_alg = digest_list->digests[i].hash_alg;
len += offsetof(struct tpmt_ha, digest);
len += alg_to_len(hash_alg);
}
len += sizeof(u32); /* tcg_pcr_event2 event_size*/
return len;
}
/* tcg2_pcr_extend - Extend PCRs for a TPM2 device for a given tpml_digest_values
*
* @dev: device
* @digest_list: list of digest algorithms to extend
*
* @Return: status code
*/
static efi_status_t tcg2_pcr_extend(struct udevice *dev, u32 pcr_index,
struct tpml_digest_values *digest_list)
{
u32 rc;
size_t i;
for (i = 0; i < digest_list->count; i++) {
u32 alg = digest_list->digests[i].hash_alg;
rc = tpm2_pcr_extend(dev, pcr_index, alg,
(u8 *)&digest_list->digests[i].digest,
alg_to_len(alg));
if (rc) {
EFI_PRINT("Failed to extend PCR\n");
return EFI_DEVICE_ERROR;
}
}
return EFI_SUCCESS;
}
/* tcg2_pcr_read - Read PCRs for a TPM2 device for a given tpml_digest_values
*
* @dev: device
* @pcr_index: PCR index
* @digest_list: list of digest algorithms to extend
*
* @Return: status code
*/
static efi_status_t tcg2_pcr_read(struct udevice *dev, u32 pcr_index,
struct tpml_digest_values *digest_list)
{
struct tpm_chip_priv *priv;
unsigned int updates, pcr_select_min;
u32 rc;
size_t i;
priv = dev_get_uclass_priv(dev);
if (!priv)
return EFI_DEVICE_ERROR;
pcr_select_min = priv->pcr_select_min;
for (i = 0; i < digest_list->count; i++) {
u16 hash_alg = digest_list->digests[i].hash_alg;
u8 *digest = (u8 *)&digest_list->digests[i].digest;
rc = tpm2_pcr_read(dev, pcr_index, pcr_select_min,
hash_alg, digest, alg_to_len(hash_alg),
&updates);
if (rc) {
EFI_PRINT("Failed to read PCR\n");
return EFI_DEVICE_ERROR;
}
}
return EFI_SUCCESS;
}
/* put_event - Append an agile event to an eventlog
*
* @pcr_index: PCR index
* @event_type: type of event added
* @digest_list: list of digest algorithms to add
* @size: size of event
* @event: event to add
* @log: log buffer to append the event
*
*/
static void put_event(u32 pcr_index, u32 event_type,
struct tpml_digest_values *digest_list, u32 size,
u8 event[], void *log)
{
size_t pos;
size_t i;
u32 event_size;
/*
* size refers to the length of event[] only, we need to check against
* the final tcg_pcr_event2 size
*/
event_size = size + tcg_event_final_size(digest_list);
put_unaligned_le32(pcr_index, log);
pos = offsetof(struct tcg_pcr_event2, event_type);
put_unaligned_le32(event_type, (void *)((uintptr_t)log + pos));
pos = offsetof(struct tcg_pcr_event2, digests); /* count */
put_unaligned_le32(digest_list->count, (void *)((uintptr_t)log + pos));
pos += offsetof(struct tpml_digest_values, digests);
for (i = 0; i < digest_list->count; i++) {
u16 hash_alg = digest_list->digests[i].hash_alg;
u8 *digest = (u8 *)&digest_list->digests[i].digest;
put_unaligned_le16(hash_alg, (void *)((uintptr_t)log + pos));
pos += offsetof(struct tpmt_ha, digest);
memcpy((void *)((uintptr_t)log + pos), digest, alg_to_len(hash_alg));
pos += alg_to_len(hash_alg);
}
put_unaligned_le32(size, (void *)((uintptr_t)log + pos));
pos += sizeof(u32); /* tcg_pcr_event2 event_size*/
memcpy((void *)((uintptr_t)log + pos), event, size);
pos += size;
/*
* make sure the calculated buffer is what we checked against
* This check should never fail. It checks the code above is
* calculating the right length for the event we are adding
*/
if (pos != event_size)
log_err("Appending to the EventLog failed\n");
}
/* tcg2_agile_log_append - Append an agile event to an eventlog
*
* @pcr_index: PCR index
* @event_type: type of event added
* @digest_list: list of digest algorithms to add
* @size: size of event
* @event: event to add
* @log: log buffer to append the event
*
* @Return: status code
*/
static efi_status_t tcg2_agile_log_append(u32 pcr_index, u32 event_type,
struct tpml_digest_values *digest_list,
u32 size, u8 event[])
{
void *log = (void *)((uintptr_t)event_log.buffer + event_log.pos);
u32 event_size = size + tcg_event_final_size(digest_list);
struct efi_tcg2_final_events_table *final_event;
efi_status_t ret = EFI_SUCCESS;
/* if ExitBootServices hasn't been called update the normal log */
if (!event_log.ebs_called) {
if (event_log.truncated ||
event_log.pos + event_size > TPM2_EVENT_LOG_SIZE) {
event_log.truncated = true;
return EFI_VOLUME_FULL;
}
put_event(pcr_index, event_type, digest_list, size, event, log);
event_log.pos += event_size;
event_log.last_event_size = event_size;
}
if (!event_log.get_event_called)
return ret;
/* if GetEventLog has been called update FinalEventLog as well */
if (event_log.final_pos + event_size > TPM2_EVENT_LOG_SIZE)
return EFI_VOLUME_FULL;
log = (void *)((uintptr_t)event_log.final_buffer + event_log.final_pos);
put_event(pcr_index, event_type, digest_list, size, event, log);
final_event = event_log.final_buffer;
final_event->number_of_events++;
event_log.final_pos += event_size;
return ret;
}
/**
* platform_get_tpm_device() - retrieve TPM device
*
* This function retrieves the udevice implementing a TPM
*
* This function may be overridden if special initialization is needed.
*
* @dev: udevice
* Return: status code
*/
__weak efi_status_t platform_get_tpm2_device(struct udevice **dev)
{
for_each_tpm_device(*dev) {
/* Only support TPMv2 devices */
if (tpm_get_version(*dev) == TPM_V2)
return EFI_SUCCESS;
}
return EFI_NOT_FOUND;
}
/**
* platform_get_eventlog() - retrieve the eventlog address and size
*
* This function retrieves the eventlog address and size if the underlying
* firmware has done some measurements and passed them.
*
* This function may be overridden based on platform specific method of
* passing the eventlog address and size.
*
* @dev: udevice
* @addr: eventlog address
* @sz: eventlog size
* Return: status code
*/
__weak efi_status_t platform_get_eventlog(struct udevice *dev, u64 *addr,
u32 *sz)
{
const u64 *basep;
const u32 *sizep;
basep = dev_read_prop(dev, "tpm_event_log_addr", NULL);
if (!basep)
return EFI_NOT_FOUND;
*addr = be64_to_cpup((__force __be64 *)basep);
sizep = dev_read_prop(dev, "tpm_event_log_size", NULL);
if (!sizep)
return EFI_NOT_FOUND;
*sz = be32_to_cpup((__force __be32 *)sizep);
if (*sz == 0) {
log_debug("event log empty\n");
return EFI_NOT_FOUND;
}
return EFI_SUCCESS;
}
/**
* tpm2_get_max_command_size() - get the supported max command size
*
* @dev: TPM device
* @max_command_size: output buffer for the size
*
* Return: 0 on success, -1 on error
*/
static int tpm2_get_max_command_size(struct udevice *dev, u16 *max_command_size)
{
u8 response[TPM2_RESPONSE_BUFFER_SIZE];
u32 ret;
memset(response, 0, sizeof(response));
ret = tpm2_get_capability(dev, TPM2_CAP_TPM_PROPERTIES,
TPM2_PT_MAX_COMMAND_SIZE, response, 1);
if (ret)
return -1;
*max_command_size = (uint16_t)get_unaligned_be32(response +
properties_offset);
return 0;
}
/**
* tpm2_get_max_response_size() - get the supported max response size
*
* @dev: TPM device
* @max_response_size: output buffer for the size
*
* Return: 0 on success, -1 on error
*/
static int tpm2_get_max_response_size(struct udevice *dev,
u16 *max_response_size)
{
u8 response[TPM2_RESPONSE_BUFFER_SIZE];
u32 ret;
memset(response, 0, sizeof(response));
ret = tpm2_get_capability(dev, TPM2_CAP_TPM_PROPERTIES,
TPM2_PT_MAX_RESPONSE_SIZE, response, 1);
if (ret)
return -1;
*max_response_size = (uint16_t)get_unaligned_be32(response +
properties_offset);
return 0;
}
/**
* tpm2_get_manufacturer_id() - get the manufacturer ID
*
* @dev: TPM device
* @manufacturer_id: output buffer for the id
*
* Return: 0 on success, -1 on error
*/
static int tpm2_get_manufacturer_id(struct udevice *dev, u32 *manufacturer_id)
{
u8 response[TPM2_RESPONSE_BUFFER_SIZE];
u32 ret;
memset(response, 0, sizeof(response));
ret = tpm2_get_capability(dev, TPM2_CAP_TPM_PROPERTIES,
TPM2_PT_MANUFACTURER, response, 1);
if (ret)
return -1;
*manufacturer_id = get_unaligned_be32(response + properties_offset);
return 0;
}
/**
* tpm2_get_num_pcr() - get the number of PCRs
*
* @dev: TPM device
* @manufacturer_id: output buffer for the number
*
* Return: 0 on success, -1 on error
*/
static int tpm2_get_num_pcr(struct udevice *dev, u32 *num_pcr)
{
u8 response[TPM2_RESPONSE_BUFFER_SIZE];
u32 ret;
memset(response, 0, sizeof(response));
ret = tpm2_get_capability(dev, TPM2_CAP_TPM_PROPERTIES,
TPM2_PT_PCR_COUNT, response, 1);
if (ret)
return -1;
*num_pcr = get_unaligned_be32(response + properties_offset);
if (*num_pcr > TPM2_MAX_PCRS)
return -1;
return 0;
}
/**
* is_active_pcr() - Check if a supported algorithm is active
*
* @dev: TPM device
* @selection: struct of PCR information
*
* Return: true if PCR is active
*/
static bool is_active_pcr(struct tpms_pcr_selection *selection)
{
int i;
/*
* check the pcr_select. If at least one of the PCRs supports the
* algorithm add it on the active ones
*/
for (i = 0; i < selection->size_of_select; i++) {
if (selection->pcr_select[i])
return true;
}
return false;
}
/**
* tpm2_get_pcr_info() - get the supported, active PCRs and number of banks
*
* @dev: TPM device
* @supported_pcr: bitmask with the algorithms supported
* @active_pcr: bitmask with the active algorithms
* @pcr_banks: number of PCR banks
*
* Return: 0 on success, -1 on error
*/
static int tpm2_get_pcr_info(struct udevice *dev, u32 *supported_pcr,
u32 *active_pcr, u32 *pcr_banks)
{
u8 response[TPM2_RESPONSE_BUFFER_SIZE];
struct tpml_pcr_selection pcrs;
u32 ret, num_pcr;
size_t i;
int tpm_ret;
*supported_pcr = 0;
*active_pcr = 0;
*pcr_banks = 0;
memset(response, 0, sizeof(response));
ret = tpm2_get_capability(dev, TPM2_CAP_PCRS, 0, response, 1);
if (ret)
goto out;
pcrs.count = get_unaligned_be32(response);
/*
* We only support 5 algorithms for now so check against that
* instead of TPM2_NUM_PCR_BANKS
*/
if (pcrs.count > MAX_HASH_COUNT || pcrs.count < 1)
goto out;
tpm_ret = tpm2_get_num_pcr(dev, &num_pcr);
if (tpm_ret)
goto out;
for (i = 0; i < pcrs.count; i++) {
/*
* Definition of TPMS_PCR_SELECTION Structure
* hash: u16
* size_of_select: u8
* pcr_select: u8 array
*
* The offsets depend on the number of the device PCRs
* so we have to calculate them based on that
*/
u32 hash_offset = offsetof(struct tpml_pcr_selection, selection) +
i * offsetof(struct tpms_pcr_selection, pcr_select) +
i * ((num_pcr + 7) / 8);
u32 size_select_offset =
hash_offset + offsetof(struct tpms_pcr_selection,
size_of_select);
u32 pcr_select_offset =
hash_offset + offsetof(struct tpms_pcr_selection,
pcr_select);
pcrs.selection[i].hash =
get_unaligned_be16(response + hash_offset);
pcrs.selection[i].size_of_select =
__get_unaligned_be(response + size_select_offset);
if (pcrs.selection[i].size_of_select > TPM2_PCR_SELECT_MAX)
goto out;
/* copy the array of pcr_select */
memcpy(pcrs.selection[i].pcr_select, response + pcr_select_offset,
pcrs.selection[i].size_of_select);
}
for (i = 0; i < pcrs.count; i++) {
u32 hash_mask = alg_to_mask(pcrs.selection[i].hash);
if (hash_mask) {
*supported_pcr |= hash_mask;
if (is_active_pcr(&pcrs.selection[i]))
*active_pcr |= hash_mask;
} else {
EFI_PRINT("Unknown algorithm %x\n", pcrs.selection[i].hash);
}
}
*pcr_banks = pcrs.count;
return 0;
out:
return -1;
}
/**
* __get_active_pcr_banks() - returns the currently active PCR banks
*
* @active_pcr_banks: pointer for receiving the bitmap of currently
* active PCR banks
*
* Return: status code
*/
static efi_status_t __get_active_pcr_banks(u32 *active_pcr_banks)
{
struct udevice *dev;
u32 active = 0, supported = 0, pcr_banks = 0;
efi_status_t ret;
int err;
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
goto out;
err = tpm2_get_pcr_info(dev, &supported, &active, &pcr_banks);
if (err) {
ret = EFI_DEVICE_ERROR;
goto out;
}
*active_pcr_banks = active;
out:
return ret;
}
/* tcg2_create_digest - create a list of digests of the supported PCR banks
* for a given memory range
*
* @input: input memory
* @length: length of buffer to calculate the digest
* @digest_list: list of digests to fill in
*
* Return: status code
*/
static efi_status_t tcg2_create_digest(const u8 *input, u32 length,
struct tpml_digest_values *digest_list)
{
sha1_context ctx;
sha256_context ctx_256;
sha512_context ctx_512;
u8 final[TPM2_SHA512_DIGEST_SIZE];
efi_status_t ret;
u32 active;
size_t i;
ret = __get_active_pcr_banks(&active);
if (ret != EFI_SUCCESS)
return ret;
digest_list->count = 0;
for (i = 0; i < MAX_HASH_COUNT; i++) {
u16 hash_alg = hash_algo_list[i].hash_alg;
if (!(active & alg_to_mask(hash_alg)))
continue;
switch (hash_alg) {
case TPM2_ALG_SHA1:
sha1_starts(&ctx);
sha1_update(&ctx, input, length);
sha1_finish(&ctx, final);
break;
case TPM2_ALG_SHA256:
sha256_starts(&ctx_256);
sha256_update(&ctx_256, input, length);
sha256_finish(&ctx_256, final);
break;
case TPM2_ALG_SHA384:
sha384_starts(&ctx_512);
sha384_update(&ctx_512, input, length);
sha384_finish(&ctx_512, final);
break;
case TPM2_ALG_SHA512:
sha512_starts(&ctx_512);
sha512_update(&ctx_512, input, length);
sha512_finish(&ctx_512, final);
break;
default:
EFI_PRINT("Unsupported algorithm %x\n", hash_alg);
return EFI_INVALID_PARAMETER;
}
digest_list->digests[digest_list->count].hash_alg = hash_alg;
memcpy(&digest_list->digests[digest_list->count].digest, final,
(u32)alg_to_len(hash_alg));
digest_list->count++;
}
return EFI_SUCCESS;
}
/**
* efi_tcg2_get_capability() - protocol capability information and state information
*
* @this: TCG2 protocol instance
* @capability: caller allocated memory with size field to the size of
* the structure allocated
* Return: status code
*/
static efi_status_t EFIAPI
efi_tcg2_get_capability(struct efi_tcg2_protocol *this,
struct efi_tcg2_boot_service_capability *capability)
{
struct udevice *dev;
efi_status_t efi_ret;
int ret;
EFI_ENTRY("%p, %p", this, capability);
if (!this || !capability) {
efi_ret = EFI_INVALID_PARAMETER;
goto out;
}
if (capability->size < BOOT_SERVICE_CAPABILITY_MIN) {
capability->size = BOOT_SERVICE_CAPABILITY_MIN;
efi_ret = EFI_BUFFER_TOO_SMALL;
goto out;
}
if (capability->size < sizeof(*capability)) {
capability->size = sizeof(*capability);
efi_ret = EFI_BUFFER_TOO_SMALL;
goto out;
}
capability->structure_version.major = 1;
capability->structure_version.minor = 1;
capability->protocol_version.major = 1;
capability->protocol_version.minor = 1;
efi_ret = platform_get_tpm2_device(&dev);
if (efi_ret != EFI_SUCCESS) {
capability->supported_event_logs = 0;
capability->hash_algorithm_bitmap = 0;
capability->tpm_present_flag = false;
capability->max_command_size = 0;
capability->max_response_size = 0;
capability->manufacturer_id = 0;
capability->number_of_pcr_banks = 0;
capability->active_pcr_banks = 0;
efi_ret = EFI_SUCCESS;
goto out;
}
/* We only allow a TPMv2 device to register the EFI protocol */
capability->supported_event_logs = TCG2_EVENT_LOG_FORMAT_TCG_2;
capability->tpm_present_flag = true;
/* Supported and active PCRs */
capability->hash_algorithm_bitmap = 0;
capability->active_pcr_banks = 0;
ret = tpm2_get_pcr_info(dev, &capability->hash_algorithm_bitmap,
&capability->active_pcr_banks,
&capability->number_of_pcr_banks);
if (ret) {
efi_ret = EFI_DEVICE_ERROR;
goto out;
}
/* Max command size */
ret = tpm2_get_max_command_size(dev, &capability->max_command_size);
if (ret) {
efi_ret = EFI_DEVICE_ERROR;
goto out;
}
/* Max response size */
ret = tpm2_get_max_response_size(dev, &capability->max_response_size);
if (ret) {
efi_ret = EFI_DEVICE_ERROR;
goto out;
}
/* Manufacturer ID */
ret = tpm2_get_manufacturer_id(dev, &capability->manufacturer_id);
if (ret) {
efi_ret = EFI_DEVICE_ERROR;
goto out;
}
return EFI_EXIT(EFI_SUCCESS);
out:
return EFI_EXIT(efi_ret);
}
/**
* efi_tcg2_get_eventlog() - retrieve the the address of an event log and its
* last entry
*
* @this: TCG2 protocol instance
* @log_format: type of event log format
* @event_log_location: pointer to the memory address of the event log
* @event_log_last_entry: pointer to the address of the start of the last
* entry in the event log in memory, if log contains
* more than 1 entry
* @event_log_truncated: set to true, if the Event Log is missing at i
* least one entry
*
* Return: status code
*/
static efi_status_t EFIAPI
efi_tcg2_get_eventlog(struct efi_tcg2_protocol *this,
efi_tcg_event_log_format log_format,
u64 *event_log_location, u64 *event_log_last_entry,
bool *event_log_truncated)
{
efi_status_t ret = EFI_SUCCESS;
struct udevice *dev;
EFI_ENTRY("%p, %u, %p, %p, %p", this, log_format, event_log_location,
event_log_last_entry, event_log_truncated);
if (!this || !event_log_location || !event_log_last_entry ||
!event_log_truncated) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
/* Only support TPMV2 */
if (log_format != TCG2_EVENT_LOG_FORMAT_TCG_2) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS) {
event_log_location = NULL;
event_log_last_entry = NULL;
*event_log_truncated = false;
ret = EFI_SUCCESS;
goto out;
}
*event_log_location = (uintptr_t)event_log.buffer;
*event_log_last_entry = (uintptr_t)(event_log.buffer + event_log.pos -
event_log.last_event_size);
*event_log_truncated = event_log.truncated;
event_log.get_event_called = true;
out:
return EFI_EXIT(ret);
}
/**
* tcg2_hash_pe_image() - calculate PE/COFF image hash
*
* @efi: pointer to the EFI binary
* @efi_size: size of @efi binary
* @digest_list: list of digest algorithms to extend
*
* Return: status code
*/
static efi_status_t tcg2_hash_pe_image(void *efi, u64 efi_size,
struct tpml_digest_values *digest_list)
{
WIN_CERTIFICATE *wincerts = NULL;
size_t wincerts_len;
struct efi_image_regions *regs = NULL;
void *new_efi = NULL;
u8 hash[TPM2_SHA512_DIGEST_SIZE];
efi_status_t ret;
u32 active;
int i;
new_efi = efi_prepare_aligned_image(efi, &efi_size);
if (!new_efi)
return EFI_OUT_OF_RESOURCES;
if (!efi_image_parse(new_efi, efi_size, &regs, &wincerts,
&wincerts_len)) {
log_err("Parsing PE executable image failed\n");
ret = EFI_UNSUPPORTED;
goto out;
}
ret = __get_active_pcr_banks(&active);
if (ret != EFI_SUCCESS) {
goto out;
}
digest_list->count = 0;
for (i = 0; i < MAX_HASH_COUNT; i++) {
u16 hash_alg = hash_algo_list[i].hash_alg;
if (!(active & alg_to_mask(hash_alg)))
continue;
switch (hash_alg) {
case TPM2_ALG_SHA1:
hash_calculate("sha1", regs->reg, regs->num, hash);
break;
case TPM2_ALG_SHA256:
hash_calculate("sha256", regs->reg, regs->num, hash);
break;
case TPM2_ALG_SHA384:
hash_calculate("sha384", regs->reg, regs->num, hash);
break;
case TPM2_ALG_SHA512:
hash_calculate("sha512", regs->reg, regs->num, hash);
break;
default:
EFI_PRINT("Unsupported algorithm %x\n", hash_alg);
return EFI_INVALID_PARAMETER;
}
digest_list->digests[digest_list->count].hash_alg = hash_alg;
memcpy(&digest_list->digests[digest_list->count].digest, hash,
(u32)alg_to_len(hash_alg));
digest_list->count++;
}
out:
if (new_efi != efi)
free(new_efi);
free(regs);
return ret;
}
/**
* tcg2_measure_pe_image() - measure PE/COFF image
*
* @efi: pointer to the EFI binary
* @efi_size: size of @efi binary
* @handle: loaded image handle
* @loaded_image: loaded image protocol
*
* Return: status code
*/
efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size,
struct efi_loaded_image_obj *handle,
struct efi_loaded_image *loaded_image)
{
struct tpml_digest_values digest_list;
efi_status_t ret;
struct udevice *dev;
u32 pcr_index, event_type, event_size;
struct uefi_image_load_event *image_load_event;
struct efi_device_path *device_path;
u32 device_path_length;
IMAGE_DOS_HEADER *dos;
IMAGE_NT_HEADERS32 *nt;
struct efi_handler *handler;
if (!is_tcg2_protocol_installed())
return EFI_SUCCESS;
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
return EFI_SECURITY_VIOLATION;
switch (handle->image_type) {
case IMAGE_SUBSYSTEM_EFI_APPLICATION:
pcr_index = 4;
event_type = EV_EFI_BOOT_SERVICES_APPLICATION;
break;
case IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER:
pcr_index = 2;
event_type = EV_EFI_BOOT_SERVICES_DRIVER;
break;
case IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER:
pcr_index = 2;
event_type = EV_EFI_RUNTIME_SERVICES_DRIVER;
break;
default:
return EFI_UNSUPPORTED;
}
ret = tcg2_hash_pe_image(efi, efi_size, &digest_list);
if (ret != EFI_SUCCESS)
return ret;
ret = tcg2_pcr_extend(dev, pcr_index, &digest_list);
if (ret != EFI_SUCCESS)
return ret;
ret = efi_search_protocol(&handle->header,
&efi_guid_loaded_image_device_path, &handler);
if (ret != EFI_SUCCESS)
return ret;
device_path = handler->protocol_interface;
device_path_length = efi_dp_size(device_path);
if (device_path_length > 0) {
/* add end node size */
device_path_length += sizeof(struct efi_device_path);
}
event_size = sizeof(struct uefi_image_load_event) + device_path_length;
image_load_event = calloc(1, event_size);
if (!image_load_event)
return EFI_OUT_OF_RESOURCES;
image_load_event->image_location_in_memory = (uintptr_t)efi;
image_load_event->image_length_in_memory = efi_size;
image_load_event->length_of_device_path = device_path_length;
dos = (IMAGE_DOS_HEADER *)efi;
nt = (IMAGE_NT_HEADERS32 *)(efi + dos->e_lfanew);
if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
IMAGE_NT_HEADERS64 *nt64 = (IMAGE_NT_HEADERS64 *)nt;
image_load_event->image_link_time_address =
nt64->OptionalHeader.ImageBase;
} else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
image_load_event->image_link_time_address =
nt->OptionalHeader.ImageBase;
} else {
ret = EFI_INVALID_PARAMETER;
goto out;
}
/* device_path_length might be zero */
memcpy(image_load_event->device_path, device_path, device_path_length);
ret = tcg2_agile_log_append(pcr_index, event_type, &digest_list,
event_size, (u8 *)image_load_event);
out:
free(image_load_event);
return ret;
}
/**
* efi_tcg2_hash_log_extend_event() - extend and optionally log events
*
* @this: TCG2 protocol instance
* @flags: bitmap providing additional information on the
* operation
* @data_to_hash: physical address of the start of the data buffer
* to be hashed
* @data_to_hash_len: the length in bytes of the buffer referenced by
* data_to_hash
* @efi_tcg_event: pointer to data buffer containing information
* about the event
*
* Return: status code
*/
static efi_status_t EFIAPI
efi_tcg2_hash_log_extend_event(struct efi_tcg2_protocol *this, u64 flags,
u64 data_to_hash, u64 data_to_hash_len,
struct efi_tcg2_event *efi_tcg_event)
{
struct udevice *dev;
efi_status_t ret;
u32 event_type, pcr_index, event_size;
struct tpml_digest_values digest_list;
EFI_ENTRY("%p, %llu, %llu, %llu, %p", this, flags, data_to_hash,
data_to_hash_len, efi_tcg_event);
if (!this || !data_to_hash || !efi_tcg_event) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
goto out;
if (efi_tcg_event->size < efi_tcg_event->header.header_size +
sizeof(u32)) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
if (efi_tcg_event->header.pcr_index > EFI_TCG2_MAX_PCR_INDEX) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
/*
* if PE_COFF_IMAGE is set we need to make sure the image is not
* corrupted, verify it and hash the PE/COFF image in accordance with
* the procedure specified in "Calculating the PE Image Hash"
* section of the "Windows Authenticode Portable Executable Signature
* Format"
*/
if (flags & PE_COFF_IMAGE) {
IMAGE_NT_HEADERS32 *nt;
ret = efi_check_pe((void *)(uintptr_t)data_to_hash,
data_to_hash_len, (void **)&nt);
if (ret != EFI_SUCCESS) {
log_err("Not a valid PE-COFF file\n");
ret = EFI_UNSUPPORTED;
goto out;
}
ret = tcg2_hash_pe_image((void *)(uintptr_t)data_to_hash,
data_to_hash_len, &digest_list);
} else {
ret = tcg2_create_digest((u8 *)(uintptr_t)data_to_hash,
data_to_hash_len, &digest_list);
}
if (ret != EFI_SUCCESS)
goto out;
pcr_index = efi_tcg_event->header.pcr_index;
event_type = efi_tcg_event->header.event_type;
ret = tcg2_pcr_extend(dev, pcr_index, &digest_list);
if (ret != EFI_SUCCESS)
goto out;
if (flags & EFI_TCG2_EXTEND_ONLY) {
if (event_log.truncated)
ret = EFI_VOLUME_FULL;
goto out;
}
/*
* The efi_tcg_event size includes the size component and the
* headersize
*/
event_size = efi_tcg_event->size - sizeof(efi_tcg_event->size) -
efi_tcg_event->header.header_size;
ret = tcg2_agile_log_append(pcr_index, event_type, &digest_list,
event_size, efi_tcg_event->event);
out:
return EFI_EXIT(ret);
}
/**
* efi_tcg2_submit_command() - Send command to the TPM
*
* @this: TCG2 protocol instance
* @input_param_block_size: size of the TPM input parameter block
* @input_param_block: pointer to the TPM input parameter block
* @output_param_block_size: size of the TPM output parameter block
* @output_param_block: pointer to the TPM output parameter block
*
* Return: status code
*/
static efi_status_t EFIAPI
efi_tcg2_submit_command(struct efi_tcg2_protocol *this,
u32 input_param_block_size,
u8 *input_param_block,
u32 output_param_block_size,
u8 *output_param_block)
{
struct udevice *dev;
efi_status_t ret;
u32 rc;
size_t resp_buf_size = output_param_block_size;
EFI_ENTRY("%p, %u, %p, %u, %p", this, input_param_block_size,
input_param_block, output_param_block_size, output_param_block);
if (!this || !input_param_block || !input_param_block_size) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
goto out;
rc = tpm2_submit_command(dev, input_param_block,
output_param_block, &resp_buf_size);
if (rc) {
ret = (rc == -ENOSPC) ? EFI_OUT_OF_RESOURCES : EFI_DEVICE_ERROR;
goto out;
}
out:
return EFI_EXIT(ret);
}
/**
* efi_tcg2_get_active_pcr_banks() - returns the currently active PCR banks
*
* @this: TCG2 protocol instance
* @active_pcr_banks: pointer for receiving the bitmap of currently
* active PCR banks
*
* Return: status code
*/
static efi_status_t EFIAPI
efi_tcg2_get_active_pcr_banks(struct efi_tcg2_protocol *this,
u32 *active_pcr_banks)
{
efi_status_t ret;
if (!this || !active_pcr_banks) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
EFI_ENTRY("%p, %p", this, active_pcr_banks);
ret = __get_active_pcr_banks(active_pcr_banks);
out:
return EFI_EXIT(ret);
}
/**
* efi_tcg2_set_active_pcr_banks() - sets the currently active PCR banks
*
* @this: TCG2 protocol instance
* @active_pcr_banks: bitmap of the requested active PCR banks
*
* Return: status code
*/
static efi_status_t EFIAPI
efi_tcg2_set_active_pcr_banks(__maybe_unused struct efi_tcg2_protocol *this,
u32 __maybe_unused active_pcr_banks)
{
return EFI_UNSUPPORTED;
}
/**
* efi_tcg2_get_result_of_set_active_pcr_banks() - retrieve result for previous
* set_active_pcr_banks()
*
* @this: TCG2 protocol instance
* @operation_present: non-zero value to indicate a
* set_active_pcr_banks operation was
* invoked during last boot
* @response: result value could be returned
*
* Return: status code
*/
static efi_status_t EFIAPI
efi_tcg2_get_result_of_set_active_pcr_banks(__maybe_unused struct efi_tcg2_protocol *this,
u32 __maybe_unused *operation_present,
u32 __maybe_unused *response)
{
return EFI_UNSUPPORTED;
}
static const struct efi_tcg2_protocol efi_tcg2_protocol = {
.get_capability = efi_tcg2_get_capability,
.get_eventlog = efi_tcg2_get_eventlog,
.hash_log_extend_event = efi_tcg2_hash_log_extend_event,
.submit_command = efi_tcg2_submit_command,
.get_active_pcr_banks = efi_tcg2_get_active_pcr_banks,
.set_active_pcr_banks = efi_tcg2_set_active_pcr_banks,
.get_result_of_set_active_pcr_banks = efi_tcg2_get_result_of_set_active_pcr_banks,
};
/**
* parse_event_log_header() - Parse and verify the event log header fields
*
* @buffer: Pointer to the start of the eventlog
* @size: Size of the eventlog
* @pos: Return offset of the next event in buffer right
* after the event header i.e specID
*
* Return: status code
*/
static efi_status_t parse_event_log_header(void *buffer, u32 size, u32 *pos)
{
struct tcg_pcr_event *event_header = (struct tcg_pcr_event *)buffer;
int i = 0;
if (size < sizeof(*event_header))
return EFI_COMPROMISED_DATA;
if (get_unaligned_le32(&event_header->pcr_index) != 0 ||
get_unaligned_le32(&event_header->event_type) != EV_NO_ACTION)
return EFI_COMPROMISED_DATA;
for (i = 0; i < sizeof(event_header->digest); i++) {
if (event_header->digest[i])
return EFI_COMPROMISED_DATA;
}
*pos += sizeof(*event_header);
return EFI_SUCCESS;
}
/**
* parse_specid_event() - Parse and verify the specID Event in the eventlog
*
* @dev: udevice
* @buffer: Pointer to the start of the eventlog
* @log_size: Size of the eventlog
* @pos: [in] Offset of specID event in the eventlog buffer
* [out] Return offset of the next event in the buffer
* after the specID
* @digest_list: list of digests in the event
*
* Return: status code
* @pos Offset in the eventlog where the specID event ends
* @digest_list: list of digests in the event
*/
static efi_status_t parse_specid_event(struct udevice *dev, void *buffer,
u32 log_size, u32 *pos,
struct tpml_digest_values *digest_list)
{
struct tcg_efi_spec_id_event *spec_event;
struct tcg_pcr_event *event_header = (struct tcg_pcr_event *)buffer;
size_t spec_event_size;
u32 active = 0, supported = 0, pcr_count = 0, alg_count = 0;
u32 spec_active = 0;
u16 hash_alg;
u8 vendor_sz;
int err, i;
if (*pos >= log_size || (*pos + sizeof(*spec_event)) > log_size)
return EFI_COMPROMISED_DATA;
/* Check specID event data */
spec_event = (struct tcg_efi_spec_id_event *)((uintptr_t)buffer + *pos);
/* Check for signature */
if (memcmp(spec_event->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03,
sizeof(TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03))) {
log_err("specID Event: Signature mismatch\n");
return EFI_COMPROMISED_DATA;
}
if (spec_event->spec_version_minor !=
TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2 ||
spec_event->spec_version_major !=
TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2)
return EFI_COMPROMISED_DATA;
if (spec_event->number_of_algorithms > MAX_HASH_COUNT ||
spec_event->number_of_algorithms < 1) {
log_err("specID Event: Number of algorithms incorrect\n");
return EFI_COMPROMISED_DATA;
}
alg_count = spec_event->number_of_algorithms;
err = tpm2_get_pcr_info(dev, &supported, &active, &pcr_count);
if (err)
return EFI_DEVICE_ERROR;
digest_list->count = 0;
/*
* We have to take care that the sequence of algorithms that we record
* in digest_list matches the sequence in eventlog.
*/
for (i = 0; i < alg_count; i++) {
hash_alg =
get_unaligned_le16(&spec_event->digest_sizes[i].algorithm_id);
if (!(supported & alg_to_mask(hash_alg))) {
log_err("specID Event: Unsupported algorithm\n");
return EFI_COMPROMISED_DATA;
}
digest_list->digests[digest_list->count++].hash_alg = hash_alg;
spec_active |= alg_to_mask(hash_alg);
}
/*
* TCG specification expects the event log to have hashes for all
* active PCR's
*/
if (spec_active != active) {
/*
* Previous stage bootloader should know all the active PCR's
* and use them in the Eventlog.
*/
log_err("specID Event: All active hash alg not present\n");
return EFI_COMPROMISED_DATA;
}
/*
* the size of the spec event and placement of vendor_info_size
* depends on supported algoriths
*/
spec_event_size =
offsetof(struct tcg_efi_spec_id_event, digest_sizes) +
alg_count * sizeof(spec_event->digest_sizes[0]);
if (*pos + spec_event_size >= log_size)
return EFI_COMPROMISED_DATA;
vendor_sz = *(uint8_t *)((uintptr_t)buffer + *pos + spec_event_size);
spec_event_size += sizeof(vendor_sz) + vendor_sz;
*pos += spec_event_size;
if (get_unaligned_le32(&event_header->event_size) != spec_event_size) {
log_err("specID event: header event size mismatch\n");
/* Right way to handle this can be to call SetActive PCR's */
return EFI_COMPROMISED_DATA;
}
return EFI_SUCCESS;
}
/**
* tcg2_parse_event() - Parse the event in the eventlog
*
* @dev: udevice
* @buffer: Pointer to the start of the eventlog
* @log_size: Size of the eventlog
* @offset: [in] Offset of the event in the eventlog buffer
* [out] Return offset of the next event in the buffer
* @digest_list: list of digests in the event
* @pcr Index of the PCR in the event
*
* Return: status code
*/
static efi_status_t tcg2_parse_event(struct udevice *dev, void *buffer,
u32 log_size, u32 *offset,
struct tpml_digest_values *digest_list,
u32 *pcr)
{
struct tcg_pcr_event2 *event = NULL;
u32 count, size, event_size;
size_t pos;
event_size = tcg_event_final_size(digest_list);
if (*offset >= log_size || *offset + event_size > log_size) {
log_err("Event exceeds log size\n");
return EFI_COMPROMISED_DATA;
}
event = (struct tcg_pcr_event2 *)((uintptr_t)buffer + *offset);
*pcr = get_unaligned_le32(&event->pcr_index);
/* get the count */
count = get_unaligned_le32(&event->digests.count);
if (count != digest_list->count)
return EFI_COMPROMISED_DATA;
pos = offsetof(struct tcg_pcr_event2, digests);
pos += offsetof(struct tpml_digest_values, digests);
for (int i = 0; i < digest_list->count; i++) {
u16 alg;
u16 hash_alg = digest_list->digests[i].hash_alg;
u8 *digest = (u8 *)&digest_list->digests[i].digest;
alg = get_unaligned_le16((void *)((uintptr_t)event + pos));
if (alg != hash_alg)
return EFI_COMPROMISED_DATA;
pos += offsetof(struct tpmt_ha, digest);
memcpy(digest, (void *)((uintptr_t)event + pos), alg_to_len(hash_alg));
pos += alg_to_len(hash_alg);
}
size = get_unaligned_le32((void *)((uintptr_t)event + pos));
event_size += size;
pos += sizeof(u32); /* tcg_pcr_event2 event_size*/
pos += size;
/* make sure the calculated buffer is what we checked against */
if (pos != event_size)
return EFI_COMPROMISED_DATA;
if (pos > log_size)
return EFI_COMPROMISED_DATA;
*offset += pos;
return EFI_SUCCESS;
}
/**
* tcg2_get_fw_eventlog() - Get the eventlog address and size
*
* If the previous firmware has passed some eventlog, this function get it's
* location and check for it's validity.
*
* @dev: udevice
* @log_buffer: eventlog address
* @log_sz: eventlog size
*
* Return: status code
*/
static efi_status_t tcg2_get_fw_eventlog(struct udevice *dev, void *log_buffer,
size_t *log_sz)
{
struct tpml_digest_values digest_list;
void *buffer;
efi_status_t ret;
u32 pcr, pos;
u64 base;
u32 sz;
bool extend_pcr = false;
int i;
ret = platform_get_eventlog(dev, &base, &sz);
if (ret != EFI_SUCCESS)
return ret;
if (sz > TPM2_EVENT_LOG_SIZE)
return EFI_VOLUME_FULL;
buffer = (void *)(uintptr_t)base;
pos = 0;
/* Parse the eventlog to check for its validity */
ret = parse_event_log_header(buffer, sz, &pos);
if (ret)
return ret;
ret = parse_specid_event(dev, buffer, sz, &pos, &digest_list);
if (ret) {
log_err("Error parsing SPEC ID Event\n");
return ret;
}
ret = tcg2_pcr_read(dev, 0, &digest_list);
if (ret) {
log_err("Error reading PCR 0\n");
return ret;
}
/*
* If PCR0 is 0, previous firmware didn't have the capability
* to extend the PCR. In this scenario, extend the PCR as
* the eventlog is parsed.
*/
for (i = 0; i < digest_list.count; i++) {
u8 hash_buf[TPM2_SHA512_DIGEST_SIZE] = { 0 };
u16 hash_alg = digest_list.digests[i].hash_alg;
if (!memcmp((u8 *)&digest_list.digests[i].digest, hash_buf,
alg_to_len(hash_alg)))
extend_pcr = true;
}
while (pos < sz) {
ret = tcg2_parse_event(dev, buffer, sz, &pos, &digest_list,
&pcr);
if (ret) {
log_err("Error parsing event\n");
return ret;
}
if (extend_pcr) {
ret = tcg2_pcr_extend(dev, pcr, &digest_list);
if (ret != EFI_SUCCESS) {
log_err("Error in extending PCR\n");
return ret;
}
/* Clear the digest for next event */
for (i = 0; i < digest_list.count; i++) {
u16 hash_alg = digest_list.digests[i].hash_alg;
u8 *digest =
(u8 *)&digest_list.digests[i].digest;
memset(digest, 0, alg_to_len(hash_alg));
}
}
}
memcpy(log_buffer, buffer, sz);
*log_sz = sz;
return ret;
}
/**
* create_specid_event() - Create the first event in the eventlog
*
* @dev: tpm device
* @event_header: Pointer to the final event header
* @event_size: final spec event size
*
* Return: status code
*/
static efi_status_t create_specid_event(struct udevice *dev, void *buffer,
size_t *event_size)
{
struct tcg_efi_spec_id_event *spec_event;
size_t spec_event_size;
efi_status_t ret = EFI_DEVICE_ERROR;
u32 active = 0, supported = 0, pcr_count = 0, alg_count = 0;
int err;
size_t i;
/*
* Create Spec event. This needs to be the first event in the log
* according to the TCG EFI protocol spec
*/
/* Setup specID event data */
spec_event = (struct tcg_efi_spec_id_event *)buffer;
memcpy(spec_event->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03,
sizeof(spec_event->signature));
put_unaligned_le32(0, &spec_event->platform_class); /* type client */
spec_event->spec_version_minor =
TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2;
spec_event->spec_version_major =
TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2;
spec_event->spec_errata =
TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_ERRATA_TPM2;
spec_event->uintn_size = sizeof(efi_uintn_t) / sizeof(u32);
err = tpm2_get_pcr_info(dev, &supported, &active, &pcr_count);
if (err)
goto out;
for (i = 0; i < pcr_count; i++) {
u16 hash_alg = hash_algo_list[i].hash_alg;
u16 hash_len = hash_algo_list[i].hash_len;
if (active & alg_to_mask(hash_alg)) {
put_unaligned_le16(hash_alg,
&spec_event->digest_sizes[alg_count].algorithm_id);
put_unaligned_le16(hash_len,
&spec_event->digest_sizes[alg_count].digest_size);
alg_count++;
}
}
spec_event->number_of_algorithms = alg_count;
if (spec_event->number_of_algorithms > MAX_HASH_COUNT ||
spec_event->number_of_algorithms < 1)
goto out;
/*
* the size of the spec event and placement of vendor_info_size
* depends on supported algoriths
*/
spec_event_size =
offsetof(struct tcg_efi_spec_id_event, digest_sizes) +
spec_event->number_of_algorithms * sizeof(spec_event->digest_sizes[0]);
/* no vendor info for us */
memset(buffer + spec_event_size, 0, 1);
/* add a byte for vendor_info_size in the spec event */
spec_event_size += 1;
*event_size = spec_event_size;
return EFI_SUCCESS;
out:
return ret;
}
/**
* tcg2_uninit - remove the final event table and free efi memory on failures
*/
void tcg2_uninit(void)
{
efi_status_t ret;
ret = efi_install_configuration_table(&efi_guid_final_events, NULL);
if (ret != EFI_SUCCESS)
log_err("Failed to delete final events config table\n");
efi_free_pool(event_log.buffer);
event_log.buffer = NULL;
efi_free_pool(event_log.final_buffer);
event_log.final_buffer = NULL;
if (!is_tcg2_protocol_installed())
return;
ret = efi_remove_protocol(efi_root, &efi_guid_tcg2_protocol,
(void *)&efi_tcg2_protocol);
if (ret != EFI_SUCCESS)
log_err("Failed to remove EFI TCG2 protocol\n");
}
/**
* create_final_event() - Create the final event and install the config
* defined by the TCG EFI spec
*/
static efi_status_t create_final_event(void)
{
struct efi_tcg2_final_events_table *final_event;
efi_status_t ret;
/*
* All events generated after the invocation of
* EFI_TCG2_GET_EVENT_LOGS need to be stored in an instance of an
* EFI_CONFIGURATION_TABLE
*/
ret = efi_allocate_pool(EFI_ACPI_MEMORY_NVS, TPM2_EVENT_LOG_SIZE,
&event_log.final_buffer);
if (ret != EFI_SUCCESS)
goto out;
memset(event_log.final_buffer, 0xff, TPM2_EVENT_LOG_SIZE);
final_event = event_log.final_buffer;
final_event->number_of_events = 0;
final_event->version = EFI_TCG2_FINAL_EVENTS_TABLE_VERSION;
event_log.final_pos = sizeof(*final_event);
ret = efi_install_configuration_table(&efi_guid_final_events,
final_event);
if (ret != EFI_SUCCESS) {
efi_free_pool(event_log.final_buffer);
event_log.final_buffer = NULL;
}
out:
return ret;
}
/**
* tcg2_measure_event() - common function to add event log and extend PCR
*
* @dev: TPM device
* @pcr_index: PCR index
* @event_type: type of event added
* @size: event size
* @event: event data
*
* Return: status code
*/
static efi_status_t
tcg2_measure_event(struct udevice *dev, u32 pcr_index, u32 event_type,
u32 size, u8 event[])
{
struct tpml_digest_values digest_list;
efi_status_t ret;
ret = tcg2_create_digest(event, size, &digest_list);
if (ret != EFI_SUCCESS)
goto out;
ret = tcg2_pcr_extend(dev, pcr_index, &digest_list);
if (ret != EFI_SUCCESS)
goto out;
ret = tcg2_agile_log_append(pcr_index, event_type, &digest_list,
size, event);
out:
return ret;
}
/**
* efi_append_scrtm_version - Append an S-CRTM EV_S_CRTM_VERSION event on the
* eventlog and extend the PCRs
*
* @dev: TPM device
*
* @Return: status code
*/
static efi_status_t efi_append_scrtm_version(struct udevice *dev)
{
efi_status_t ret;
ret = tcg2_measure_event(dev, 0, EV_S_CRTM_VERSION,
strlen(version_string) + 1,
(u8 *)version_string);
return ret;
}
/**
* efi_init_event_log() - initialize an eventlog
*
* Return: status code
*/
static efi_status_t efi_init_event_log(void)
{
/*
* vendor_info_size is currently set to 0, we need to change the length
* and allocate the flexible array member if this changes
*/
struct tcg_pcr_event *event_header = NULL;
struct udevice *dev;
size_t spec_event_size;
efi_status_t ret;
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
return ret;
ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, TPM2_EVENT_LOG_SIZE,
(void **)&event_log.buffer);
if (ret != EFI_SUCCESS)
return ret;
/*
* initialize log area as 0xff so the OS can easily figure out the
* last log entry
*/
memset(event_log.buffer, 0xff, TPM2_EVENT_LOG_SIZE);
/*
* The log header is defined to be in SHA1 event log entry format.
* Setup event header
*/
event_header = (struct tcg_pcr_event *)event_log.buffer;
event_log.pos = 0;
event_log.last_event_size = 0;
event_log.get_event_called = false;
event_log.ebs_called = false;
event_log.truncated = false;
/*
* Check if earlier firmware have passed any eventlog. Different
* platforms can use different ways to do so.
*/
ret = tcg2_get_fw_eventlog(dev, event_log.buffer, &event_log.pos);
/*
* If earlier firmware hasn't passed any eventlog, go ahead and
* create the eventlog header.
*/
if (ret == EFI_NOT_FOUND) {
put_unaligned_le32(0, &event_header->pcr_index);
put_unaligned_le32(EV_NO_ACTION, &event_header->event_type);
memset(&event_header->digest, 0, sizeof(event_header->digest));
ret = create_specid_event(dev,
(void *)((uintptr_t)event_log.buffer +
sizeof(*event_header)),
&spec_event_size);
if (ret != EFI_SUCCESS)
goto free_pool;
put_unaligned_le32(spec_event_size, &event_header->event_size);
event_log.pos = spec_event_size + sizeof(*event_header);
event_log.last_event_size = event_log.pos;
/*
* Add SCRTM version to the log if previous firmmware
* doesn't pass an eventlog.
*/
ret = efi_append_scrtm_version(dev);
}
if (ret != EFI_SUCCESS)
goto free_pool;
ret = create_final_event();
if (ret != EFI_SUCCESS)
goto free_pool;
return ret;
free_pool:
efi_free_pool(event_log.buffer);
event_log.buffer = NULL;
return ret;
}
/**
* tcg2_measure_variable() - add variable event log and extend PCR
*
* @dev: TPM device
* @pcr_index: PCR index
* @event_type: type of event added
* @var_name: variable name
* @guid: guid
* @data_size: variable data size
* @data: variable data
*
* Return: status code
*/
static efi_status_t tcg2_measure_variable(struct udevice *dev, u32 pcr_index,
u32 event_type, const u16 *var_name,
const efi_guid_t *guid,
efi_uintn_t data_size, u8 *data)
{
u32 event_size;
efi_status_t ret;
struct efi_tcg2_uefi_variable_data *event;
event_size = sizeof(event->variable_name) +
sizeof(event->unicode_name_length) +
sizeof(event->variable_data_length) +
(u16_strlen(var_name) * sizeof(u16)) + data_size;
event = malloc(event_size);
if (!event)
return EFI_OUT_OF_RESOURCES;
guidcpy(&event->variable_name, guid);
event->unicode_name_length = u16_strlen(var_name);
event->variable_data_length = data_size;
memcpy(event->unicode_name, var_name,
(event->unicode_name_length * sizeof(u16)));
if (data) {
memcpy((u16 *)event->unicode_name + event->unicode_name_length,
data, data_size);
}
ret = tcg2_measure_event(dev, pcr_index, event_type, event_size,
(u8 *)event);
free(event);
return ret;
}
/**
* tcg2_measure_boot_variable() - measure boot variables
*
* @dev: TPM device
*
* Return: status code
*/
static efi_status_t tcg2_measure_boot_variable(struct udevice *dev)
{
u16 *boot_order;
u16 *boot_index;
u16 var_name[] = u"BootOrder";
u16 boot_name[] = u"Boot####";
u8 *bootvar;
efi_uintn_t var_data_size;
u32 count, i;
efi_status_t ret;
boot_order = efi_get_var(var_name, &efi_global_variable_guid,
&var_data_size);
if (!boot_order) {
/* If "BootOrder" is not defined, skip the boot variable measurement */
return EFI_SUCCESS;
}
ret = tcg2_measure_variable(dev, 1, EV_EFI_VARIABLE_BOOT2, var_name,
&efi_global_variable_guid, var_data_size,
(u8 *)boot_order);
if (ret != EFI_SUCCESS)
goto error;
count = var_data_size / sizeof(*boot_order);
boot_index = boot_order;
for (i = 0; i < count; i++) {
efi_create_indexed_name(boot_name, sizeof(boot_name),
"Boot", *boot_index++);
bootvar = efi_get_var(boot_name, &efi_global_variable_guid,
&var_data_size);
if (!bootvar) {
log_debug("%ls not found\n", boot_name);
continue;
}
ret = tcg2_measure_variable(dev, 1, EV_EFI_VARIABLE_BOOT2,
boot_name,
&efi_global_variable_guid,
var_data_size, bootvar);
free(bootvar);
if (ret != EFI_SUCCESS)
goto error;
}
error:
free(boot_order);
return ret;
}
/**
* tcg2_measure_smbios() - measure smbios table
*
* @dev: TPM device
* @entry: pointer to the smbios_entry structure
*
* Return: status code
*/
static efi_status_t
tcg2_measure_smbios(struct udevice *dev,
const struct smbios_entry *entry)
{
efi_status_t ret;
struct smbios_header *smbios_copy;
struct smbios_handoff_table_pointers2 *event = NULL;
u32 event_size;
/*
* TCG PC Client PFP Spec says
* "SMBIOS structures that contain static configuration information
* (e.g. Platform Manufacturer Enterprise Number assigned by IANA,
* platform model number, Vendor and Device IDs for each SMBIOS table)
* that is relevant to the security of the platform MUST be measured".
* Device dependent parameters such as serial number are cleared to
* zero or spaces for the measurement.
*/
event_size = sizeof(struct smbios_handoff_table_pointers2) +
FIELD_SIZEOF(struct efi_configuration_table, guid) +
entry->struct_table_length;
event = calloc(1, event_size);
if (!event) {
ret = EFI_OUT_OF_RESOURCES;
goto out;
}
event->table_description_size = sizeof(SMBIOS_HANDOFF_TABLE_DESC);
memcpy(event->table_description, SMBIOS_HANDOFF_TABLE_DESC,
sizeof(SMBIOS_HANDOFF_TABLE_DESC));
put_unaligned_le64(1, &event->number_of_tables);
guidcpy(&event->table_entry[0].guid, &smbios_guid);
smbios_copy = (struct smbios_header *)((uintptr_t)&event->table_entry[0].table);
memcpy(&event->table_entry[0].table,
(void *)((uintptr_t)entry->struct_table_address),
entry->struct_table_length);
smbios_prepare_measurement(entry, smbios_copy);
ret = tcg2_measure_event(dev, 1, EV_EFI_HANDOFF_TABLES2, event_size,
(u8 *)event);
if (ret != EFI_SUCCESS)
goto out;
out:
free(event);
return ret;
}
/**
* find_smbios_table() - find smbios table
*
* Return: pointer to the smbios table
*/
static void *find_smbios_table(void)
{
u32 i;
for (i = 0; i < systab.nr_tables; i++) {
if (!guidcmp(&smbios_guid, &systab.tables[i].guid))
return systab.tables[i].table;
}
return NULL;
}
/**
* tcg2_measure_gpt_table() - measure gpt table
*
* @dev: TPM device
* @loaded_image: handle to the loaded image
*
* Return: status code
*/
static efi_status_t
tcg2_measure_gpt_data(struct udevice *dev,
struct efi_loaded_image_obj *loaded_image)
{
efi_status_t ret;
efi_handle_t handle;
struct efi_handler *dp_handler;
struct efi_device_path *orig_device_path;
struct efi_device_path *device_path;
struct efi_device_path *dp;
struct efi_block_io *block_io;
struct efi_gpt_data *event = NULL;
efi_guid_t null_guid = NULL_GUID;
gpt_header *gpt_h;
gpt_entry *entry = NULL;
gpt_entry *gpt_e;
u32 num_of_valid_entry = 0;
u32 event_size;
u32 i;
u32 total_gpt_entry_size;
ret = efi_search_protocol(&loaded_image->header,
&efi_guid_loaded_image_device_path,
&dp_handler);
if (ret != EFI_SUCCESS)
return ret;
orig_device_path = dp_handler->protocol_interface;
if (!orig_device_path) /* no device path, skip GPT measurement */
return EFI_SUCCESS;
device_path = efi_dp_dup(orig_device_path);
if (!device_path)
return EFI_OUT_OF_RESOURCES;
dp = search_gpt_dp_node(device_path);
if (!dp) {
/* no GPT device path node found, skip GPT measurement */
ret = EFI_SUCCESS;
goto out1;
}
/* read GPT header */
dp->type = DEVICE_PATH_TYPE_END;
dp->sub_type = DEVICE_PATH_SUB_TYPE_END;
dp = device_path;
ret = EFI_CALL(systab.boottime->locate_device_path(&efi_block_io_guid,
&dp, &handle));
if (ret != EFI_SUCCESS)
goto out1;
ret = EFI_CALL(efi_handle_protocol(handle,
&efi_block_io_guid, (void **)&block_io));
if (ret != EFI_SUCCESS)
goto out1;
gpt_h = memalign(block_io->media->io_align, block_io->media->block_size);
if (!gpt_h) {
ret = EFI_OUT_OF_RESOURCES;
goto out2;
}
ret = block_io->read_blocks(block_io, block_io->media->media_id, 1,
block_io->media->block_size, gpt_h);
if (ret != EFI_SUCCESS)
goto out2;
/* read GPT entry */
total_gpt_entry_size = gpt_h->num_partition_entries *
gpt_h->sizeof_partition_entry;
entry = memalign(block_io->media->io_align, total_gpt_entry_size);
if (!entry) {
ret = EFI_OUT_OF_RESOURCES;
goto out2;
}
ret = block_io->read_blocks(block_io, block_io->media->media_id,
gpt_h->partition_entry_lba,
total_gpt_entry_size, entry);
if (ret != EFI_SUCCESS)
goto out2;
/* count valid GPT entry */
gpt_e = entry;
for (i = 0; i < gpt_h->num_partition_entries; i++) {
if (guidcmp(&null_guid, &gpt_e->partition_type_guid))
num_of_valid_entry++;
gpt_e = (gpt_entry *)((u8 *)gpt_e + gpt_h->sizeof_partition_entry);
}
/* prepare event data for measurement */
event_size = sizeof(struct efi_gpt_data) +
(num_of_valid_entry * gpt_h->sizeof_partition_entry);
event = calloc(1, event_size);
if (!event) {
ret = EFI_OUT_OF_RESOURCES;
goto out2;
}
memcpy(event, gpt_h, sizeof(gpt_header));
put_unaligned_le64(num_of_valid_entry, &event->number_of_partitions);
/* copy valid GPT entry */
gpt_e = entry;
num_of_valid_entry = 0;
for (i = 0; i < gpt_h->num_partition_entries; i++) {
if (guidcmp(&null_guid, &gpt_e->partition_type_guid)) {
memcpy((u8 *)event->partitions +
(num_of_valid_entry * gpt_h->sizeof_partition_entry),
gpt_e, gpt_h->sizeof_partition_entry);
num_of_valid_entry++;
}
gpt_e = (gpt_entry *)((u8 *)gpt_e + gpt_h->sizeof_partition_entry);
}
ret = tcg2_measure_event(dev, 5, EV_EFI_GPT_EVENT, event_size, (u8 *)event);
if (ret != EFI_SUCCESS)
goto out2;
out2:
EFI_CALL(efi_close_protocol((efi_handle_t)block_io, &efi_block_io_guid,
NULL, NULL));
free(gpt_h);
free(entry);
free(event);
out1:
efi_free_pool(device_path);
return ret;
}
/**
* efi_tcg2_measure_efi_app_invocation() - measure efi app invocation
*
* Return: status code
*/
efi_status_t efi_tcg2_measure_efi_app_invocation(struct efi_loaded_image_obj *handle)
{
efi_status_t ret;
u32 pcr_index;
struct udevice *dev;
u32 event = 0;
struct smbios_entry *entry;
if (!is_tcg2_protocol_installed())
return EFI_SUCCESS;
if (tcg2_efi_app_invoked)
return EFI_SUCCESS;
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
return EFI_SECURITY_VIOLATION;
ret = tcg2_measure_boot_variable(dev);
if (ret != EFI_SUCCESS)
goto out;
ret = tcg2_measure_event(dev, 4, EV_EFI_ACTION,
strlen(EFI_CALLING_EFI_APPLICATION),
(u8 *)EFI_CALLING_EFI_APPLICATION);
if (ret != EFI_SUCCESS)
goto out;
entry = (struct smbios_entry *)find_smbios_table();
if (entry) {
ret = tcg2_measure_smbios(dev, entry);
if (ret != EFI_SUCCESS)
goto out;
}
ret = tcg2_measure_gpt_data(dev, handle);
if (ret != EFI_SUCCESS)
goto out;
for (pcr_index = 0; pcr_index <= 7; pcr_index++) {
ret = tcg2_measure_event(dev, pcr_index, EV_SEPARATOR,
sizeof(event), (u8 *)&event);
if (ret != EFI_SUCCESS)
goto out;
}
tcg2_efi_app_invoked = true;
out:
return ret;
}
/**
* efi_tcg2_measure_efi_app_exit() - measure efi app exit
*
* Return: status code
*/
efi_status_t efi_tcg2_measure_efi_app_exit(void)
{
efi_status_t ret;
struct udevice *dev;
if (!is_tcg2_protocol_installed())
return EFI_SUCCESS;
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
return ret;
ret = tcg2_measure_event(dev, 4, EV_EFI_ACTION,
strlen(EFI_RETURNING_FROM_EFI_APPLICATION),
(u8 *)EFI_RETURNING_FROM_EFI_APPLICATION);
return ret;
}
/**
* efi_tcg2_notify_exit_boot_services() - ExitBootService callback
*
* @event: callback event
* @context: callback context
*/
static void EFIAPI
efi_tcg2_notify_exit_boot_services(struct efi_event *event, void *context)
{
efi_status_t ret;
struct udevice *dev;
EFI_ENTRY("%p, %p", event, context);
event_log.ebs_called = true;
if (!is_tcg2_protocol_installed()) {
ret = EFI_SUCCESS;
goto out;
}
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
goto out;
ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION),
(u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION);
if (ret != EFI_SUCCESS)
goto out;
ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
strlen(EFI_EXIT_BOOT_SERVICES_SUCCEEDED),
(u8 *)EFI_EXIT_BOOT_SERVICES_SUCCEEDED);
out:
EFI_EXIT(ret);
}
/**
* efi_tcg2_notify_exit_boot_services_failed()
* - notify ExitBootServices() is failed
*
* Return: status code
*/
efi_status_t efi_tcg2_notify_exit_boot_services_failed(void)
{
struct udevice *dev;
efi_status_t ret;
if (!is_tcg2_protocol_installed())
return EFI_SUCCESS;
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
goto out;
ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION),
(u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION);
if (ret != EFI_SUCCESS)
goto out;
ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
strlen(EFI_EXIT_BOOT_SERVICES_FAILED),
(u8 *)EFI_EXIT_BOOT_SERVICES_FAILED);
out:
return ret;
}
/**
* tcg2_measure_secure_boot_variable() - measure secure boot variables
*
* @dev: TPM device
*
* Return: status code
*/
static efi_status_t tcg2_measure_secure_boot_variable(struct udevice *dev)
{
u8 *data;
efi_uintn_t data_size;
u32 count, i;
efi_status_t ret;
u8 deployed_mode;
efi_uintn_t size;
u32 deployed_audit_pcr_index = 1;
size = sizeof(deployed_mode);
ret = efi_get_variable_int(u"DeployedMode", &efi_global_variable_guid,
NULL, &size, &deployed_mode, NULL);
if (ret != EFI_SUCCESS || !deployed_mode)
deployed_audit_pcr_index = 7;
count = ARRAY_SIZE(secure_variables);
for (i = 0; i < count; i++) {
const efi_guid_t *guid;
guid = efi_auth_var_get_guid(secure_variables[i].name);
data = efi_get_var(secure_variables[i].name, guid, &data_size);
if (!data && !secure_variables[i].accept_empty)
continue;
if (u16_strcmp(u"DeployedMode", secure_variables[i].name))
secure_variables[i].pcr_index = deployed_audit_pcr_index;
if (u16_strcmp(u"AuditMode", secure_variables[i].name))
secure_variables[i].pcr_index = deployed_audit_pcr_index;
ret = tcg2_measure_variable(dev, secure_variables[i].pcr_index,
EV_EFI_VARIABLE_DRIVER_CONFIG,
secure_variables[i].name, guid,
data_size, data);
free(data);
if (ret != EFI_SUCCESS)
goto error;
}
error:
return ret;
}
/**
* efi_tcg2_do_initial_measurement() - do initial measurement
*
* Return: status code
*/
efi_status_t efi_tcg2_do_initial_measurement(void)
{
efi_status_t ret;
struct udevice *dev;
if (!is_tcg2_protocol_installed())
return EFI_SUCCESS;
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
return EFI_SECURITY_VIOLATION;
ret = tcg2_measure_secure_boot_variable(dev);
if (ret != EFI_SUCCESS)
goto out;
out:
return ret;
}
/**
* efi_tcg2_register() - register EFI_TCG2_PROTOCOL
*
* If a TPM2 device is available, the TPM TCG2 Protocol is registered
*
* Return: status code
*/
efi_status_t efi_tcg2_register(void)
{
efi_status_t ret = EFI_SUCCESS;
struct udevice *dev;
struct efi_event *event;
u32 err;
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS) {
log_warning("Unable to find TPMv2 device\n");
return EFI_SUCCESS;
}
/* initialize the TPM as early as possible. */
err = tpm_startup(dev, TPM_ST_CLEAR);
if (err) {
log_err("TPM startup failed\n");
goto fail;
}
ret = efi_init_event_log();
if (ret != EFI_SUCCESS) {
tcg2_uninit();
goto fail;
}
ret = efi_add_protocol(efi_root, &efi_guid_tcg2_protocol,
(void *)&efi_tcg2_protocol);
if (ret != EFI_SUCCESS) {
tcg2_uninit();
goto fail;
}
ret = efi_create_event(EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,
efi_tcg2_notify_exit_boot_services, NULL,
NULL, &event);
if (ret != EFI_SUCCESS) {
tcg2_uninit();
goto fail;
}
return ret;
fail:
log_err("Cannot install EFI_TCG2_PROTOCOL\n");
return ret;
}
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