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u-boot/lib/efi_loader/efi_tcg2.c
Masahisa Kojima 54bec17f6b efi_loader: efi_tcg2_register returns appropriate error 
This commit modify efi_tcg2_register() to return the
appropriate error.
With this fix, sandbox will not boot because efi_tcg2_register()
fails due to some missing feature in GetCapabilities.
So disable sandbox if EFI_TCG2_PROTOCOL is enabled.

UEFI secure boot variable measurement is not directly related
to TCG2 protocol installation, tcg2_measure_secure_boot_variable()
is moved to the separate function.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2021-12-09 11:43:25 -08:00

2443 lines
62 KiB
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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;
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
return ret;
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[] = L"BootOrder";
u16 boot_name[] = L"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 (tcg2_efi_app_invoked)
return EFI_SUCCESS;
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
return ret;
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;
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;
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;
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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