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efi_loader: add PE/COFF image measurement

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"TCG PC Client Platform Firmware Profile Specification"
requires to measure every attempt to load and execute
a OS Loader(a UEFI application) into PCR[4].
This commit adds the PE/COFF image measurement, extends PCR,
and appends measurement into Event Log.

Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Tested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Replace CONFIG_HASH_CALCULATE by CONFIG_HASH
Fix conversions between pointers and u64.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
This commit is contained in:
Masahisa Kojima 2021-05-26 12:09:58 +09:00 committed by Heinrich Schuchardt
parent 464010b0be
commit 163a0d7e2c
6 changed files with 277 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
include/efi_loader.h
View File

@ -426,6 +426,10 @@ efi_status_t efi_disk_register(void);
efi_status_t efi_rng_register(void);
/* Called by efi_init_obj_list() to install EFI_TCG2_PROTOCOL */
efi_status_t efi_tcg2_register(void);
/* measure the pe-coff image, extend PCR and add Event Log */
efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size,
struct efi_loaded_image_obj *handle,
struct efi_loaded_image *loaded_image_info);
/* Create handles and protocols for the partitions of a block device */
int efi_disk_create_partitions(efi_handle_t parent, struct blk_desc *desc,
const char *if_typename, int diskid,
@ -886,6 +890,8 @@ bool efi_secure_boot_enabled(void);
bool efi_capsule_auth_enabled(void);
void *efi_prepare_aligned_image(void *efi, u64 *efi_size);
bool efi_image_parse(void *efi, size_t len, struct efi_image_regions **regp,
WIN_CERTIFICATE **auth, size_t *auth_len);

9
include/efi_tcg2.h
View File

@ -9,6 +9,7 @@
#if !defined _EFI_TCG2_PROTOCOL_H_
#define _EFI_TCG2_PROTOCOL_H_
#include <efi_api.h>
#include <tpm-v2.h>
#define EFI_TCG2_PROTOCOL_GUID \
@ -53,6 +54,14 @@ struct efi_tcg2_event {
u8 event[];
} __packed;
struct uefi_image_load_event {
efi_physical_addr_t image_location_in_memory;
u64 image_length_in_memory;
u64 image_link_time_address;
u64 length_of_device_path;
struct efi_device_path device_path[];
};
struct efi_tcg2_boot_service_capability {
u8 size;
struct efi_tcg2_version structure_version;

18
include/tpm-v2.h
View File

@ -70,6 +70,24 @@ struct udevice;
#define EV_TABLE_OF_DEVICES ((u32)0x0000000B)
#define EV_COMPACT_HASH ((u32)0x0000000C)
/*
* event types, cf.
* "TCG PC Client Platform Firmware Profile Specification", Family "2.0"
* rev 1.04, June 3, 2019
*/
#define EV_EFI_EVENT_BASE ((u32)0x80000000)
#define EV_EFI_VARIABLE_DRIVER_CONFIG ((u32)0x80000001)
#define EV_EFI_VARIABLE_BOOT ((u32)0x80000002)
#define EV_EFI_BOOT_SERVICES_APPLICATION ((u32)0x80000003)
#define EV_EFI_BOOT_SERVICES_DRIVER ((u32)0x80000004)
#define EV_EFI_RUNTIME_SERVICES_DRIVER ((u32)0x80000005)
#define EV_EFI_GPT_EVENT ((u32)0x80000006)
#define EV_EFI_ACTION ((u32)0x80000007)
#define EV_EFI_PLATFORM_FIRMWARE_BLOB ((u32)0x80000008)
#define EV_EFI_HANDOFF_TABLES ((u32)0x80000009)
#define EV_EFI_HCRTM_EVENT ((u32)0x80000010)
#define EV_EFI_VARIABLE_AUTHORITY ((u32)0x800000E0)
/* TPMS_TAGGED_PROPERTY Structure */
struct tpms_tagged_property {
u32 property;

1
lib/efi_loader/Kconfig
View File

@ -309,6 +309,7 @@ config EFI_TCG2_PROTOCOL
select SHA512_ALGO
select SHA384
select SHA512
select HASH
help
Provide a EFI_TCG2_PROTOCOL implementation using the TPM hardware
of the platform.

62
lib/efi_loader/efi_image_loader.c
View File

@ -302,6 +302,38 @@ static int cmp_pe_section(const void *arg1, const void *arg2)
return 1;
}
/**
* efi_prepare_aligned_image() - prepare 8-byte aligned image
* @efi: pointer to the EFI binary
* @efi_size: size of @efi binary
*
* If @efi is not 8-byte aligned, this function newly allocates
* the image buffer.
*
* Return: valid pointer to a image, return NULL if allocation fails.
*/
void *efi_prepare_aligned_image(void *efi, u64 *efi_size)
{
size_t new_efi_size;
void *new_efi;
/*
* Size must be 8-byte aligned and the trailing bytes must be
* zero'ed. Otherwise hash value may be incorrect.
*/
if (!IS_ALIGNED(*efi_size, 8)) {
new_efi_size = ALIGN(*efi_size, 8);
new_efi = calloc(new_efi_size, 1);
if (!new_efi)
return NULL;
memcpy(new_efi, efi, *efi_size);
*efi_size = new_efi_size;
return new_efi;
} else {
return efi;
}
}
/**
* efi_image_parse() - parse a PE image
* @efi: Pointer to image
@ -561,7 +593,7 @@ static bool efi_image_authenticate(void *efi, size_t efi_size)
struct efi_signature_store *db = NULL, *dbx = NULL;
void *new_efi = NULL;
u8 *auth, *wincerts_end;
size_t new_efi_size, auth_size;
size_t auth_size;
bool ret = false;
EFI_PRINT("%s: Enter, %d\n", __func__, ret);
@ -569,21 +601,11 @@ static bool efi_image_authenticate(void *efi, size_t efi_size)
if (!efi_secure_boot_enabled())
return true;
/*
* Size must be 8-byte aligned and the trailing bytes must be
* zero'ed. Otherwise hash value may be incorrect.
*/
if (efi_size & 0x7) {
new_efi_size = (efi_size + 0x7) & ~0x7ULL;
new_efi = calloc(new_efi_size, 1);
if (!new_efi)
return false;
memcpy(new_efi, efi, efi_size);
efi = new_efi;
efi_size = new_efi_size;
}
new_efi = efi_prepare_aligned_image(efi, (u64 *)&efi_size);
if (!new_efi)
return false;
if (!efi_image_parse(efi, efi_size, &regs, &wincerts,
if (!efi_image_parse(new_efi, efi_size, &regs, &wincerts,
&wincerts_len)) {
EFI_PRINT("Parsing PE executable image failed\n");
goto err;
@ -725,7 +747,8 @@ err:
efi_sigstore_free(dbx);
pkcs7_free_message(msg);
free(regs);
free(new_efi);
if (new_efi != efi)
free(new_efi);
EFI_PRINT("%s: Exit, %d\n", __func__, ret);
return ret;
@ -891,6 +914,13 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle,
goto err;
}
#if CONFIG_IS_ENABLED(EFI_TCG2_PROTOCOL)
/* Measure an PE/COFF image */
if (tcg2_measure_pe_image(efi, efi_size, handle,
loaded_image_info))
log_err("PE image measurement failed\n");
#endif
/* Copy PE headers */
memcpy(efi_reloc, efi,
sizeof(*dos)

207
lib/efi_loader/efi_tcg2.c
View File

@ -13,8 +13,10 @@
#include <efi_loader.h>
#include <efi_tcg2.h>
#include <log.h>
#include <malloc.h>
#include <version.h>
#include <tpm-v2.h>
#include <u-boot/hash-checksum.h>
#include <u-boot/sha1.h>
#include <u-boot/sha256.h>
#include <u-boot/sha512.h>
@ -710,6 +712,183 @@ 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[i].hash_alg = hash_alg;
memcpy(&digest_list->digests[i].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_CALL(efi_search_protocol(&handle->header,
&efi_guid_loaded_image_device_path,
&handler));
if (ret != EFI_SUCCESS)
return ret;
device_path = EFI_CALL(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 = (struct uefi_image_load_event *)malloc(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;
}
if (device_path_length > 0) {
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
*
@ -761,24 +940,32 @@ efi_tcg2_hash_log_extend_event(struct efi_tcg2_protocol *this, u64 flags,
/*
* 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
* the procedure specified in "Calculating the PE Image Hash"
* section of the "Windows Authenticode Portable Executable Signature
* Format"
* Not supported for now
*/
if (flags & PE_COFF_IMAGE) {
ret = EFI_UNSUPPORTED;
goto out;
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");
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_create_digest((u8 *)(uintptr_t)data_to_hash,
data_to_hash_len, &digest_list);
if (ret != EFI_SUCCESS)
goto out;
ret = tcg2_pcr_extend(dev, pcr_index, &digest_list);
if (ret != EFI_SUCCESS)
goto out;