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refactor(measured-boot): add generic macros for using Crypto library 

It doesn't look correct to use mbed TLS defines directly in the Event
Log driver as this driver may use another Crypto library in future.
Hence mbed TLS Crypto dependency on Event Log driver is removed by
introducing generic Crypto defines and uses those in the Event Log
driver to call Crypto functions.
Also, updated mbed TLS glue layer to map these generic Crypto defines
to mbed TLS library defines.

Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: Ibc9c751f60cbce4d3f3cf049b7c53b3d05cc6735
This commit is contained in:
Manish V Badarkhe 2021-10-06 23:41:50 +01:00
parent 0628fe3fff
commit 14db963fd3
8 changed files with 114 additions and 38 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
drivers/auth/crypto_mod.c
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
* Copyright (c) 2015-2021, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@ -114,8 +114,9 @@ int crypto_mod_verify_hash(void *data_ptr, unsigned int data_len,
* data_ptr, data_len: data to be hashed
* output: resulting hash
*/
int crypto_mod_calc_hash(unsigned int alg, void *data_ptr,
unsigned int data_len, unsigned char *output)
int crypto_mod_calc_hash(enum crypto_md_algo alg, void *data_ptr,
unsigned int data_len,
unsigned char output[CRYPTO_MD_MAX_SIZE])
{
assert(data_ptr != NULL);
assert(data_len != 0);

18
drivers/auth/mbedtls/mbedtls_common.mk
View File

@ -1,5 +1,5 @@
#
# Copyright (c) 2015-2020, Arm Limited. All rights reserved.
# Copyright (c) 2015-2021, Arm Limited. All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause
#
@ -96,6 +96,18 @@ else
TF_MBEDTLS_USE_AES_GCM := 0
endif
ifeq ($(MEASURED_BOOT),1)
ifeq (${TPM_HASH_ALG}, sha256)
TF_MBEDTLS_TPM_HASH_ALG_ID := TF_MBEDTLS_SHA256
else ifeq (${TPM_HASH_ALG}, sha384)
TF_MBEDTLS_TPM_HASH_ALG_ID := TF_MBEDTLS_SHA384
else ifeq (${TPM_HASH_ALG}, sha512)
TF_MBEDTLS_TPM_HASH_ALG_ID := TF_MBEDTLS_SHA512
else
$(error "TPM_HASH_ALG not defined.")
endif
endif
# Needs to be set to drive mbed TLS configuration correctly
$(eval $(call add_defines,\
$(sort \
@ -105,6 +117,10 @@ $(eval $(call add_defines,\
TF_MBEDTLS_USE_AES_GCM \
)))
ifeq ($(MEASURED_BOOT),1)
$(eval $(call add_define,TF_MBEDTLS_TPM_HASH_ALG_ID))
endif
$(eval $(call MAKE_LIB,mbedtls))
endif

44
drivers/auth/mbedtls/mbedtls_crypto.c
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
* Copyright (c) 2015-2021, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@ -24,6 +24,16 @@
#define LIB_NAME "mbed TLS"
#if MEASURED_BOOT
/*
* CRYPTO_MD_MAX_SIZE value is as per current stronger algorithm available
* so make sure that mbed TLS MD maximum size must be lesser than this.
*/
CASSERT(CRYPTO_MD_MAX_SIZE >= MBEDTLS_MD_MAX_SIZE,
assert_mbedtls_md_size_overflow);
#endif /* MEASURED_BOOT */
/*
* AlgorithmIdentifier ::= SEQUENCE {
* algorithm OBJECT IDENTIFIER,
@ -210,22 +220,46 @@ static int verify_hash(void *data_ptr, unsigned int data_len,
}
#if MEASURED_BOOT
/*
* Map a generic crypto message digest algorithm to the corresponding macro used
* by Mbed TLS.
*/
static inline mbedtls_md_type_t md_type(enum crypto_md_algo algo)
{
switch (algo) {
case CRYPTO_MD_SHA512:
return MBEDTLS_MD_SHA512;
case CRYPTO_MD_SHA384:
return MBEDTLS_MD_SHA384;
case CRYPTO_MD_SHA256:
return MBEDTLS_MD_SHA256;
default:
/* Invalid hash algorithm. */
return MBEDTLS_MD_NONE;
}
}
/*
* Calculate a hash
*
* output points to the computed hash
*/
int calc_hash(unsigned int alg, void *data_ptr,
unsigned int data_len, unsigned char *output)
static int calc_hash(enum crypto_md_algo md_algo, void *data_ptr,
unsigned int data_len,
unsigned char output[CRYPTO_MD_MAX_SIZE])
{
const mbedtls_md_info_t *md_info;
md_info = mbedtls_md_info_from_type((mbedtls_md_type_t)alg);
md_info = mbedtls_md_info_from_type(md_type(md_algo));
if (md_info == NULL) {
return CRYPTO_ERR_HASH;
}
/* Calculate the hash of the data */
/*
* Calculate the hash of the data, it is safe to pass the
* 'output' hash buffer pointer considering its size is always
* bigger than or equal to MBEDTLS_MD_MAX_SIZE.
*/
return mbedtls_md(md_info, data_ptr, data_len, output);
}
#endif /* MEASURED_BOOT */

17
drivers/measured_boot/event_log/event_log.c
View File

@ -13,10 +13,19 @@
#include <common/debug.h>
#include <drivers/auth/crypto_mod.h>
#include <drivers/measured_boot/event_log/event_log.h>
#include <mbedtls/md.h>
#include <plat/common/platform.h>
#if TPM_ALG_ID == TPM_ALG_SHA512
#define CRYPTO_MD_ID CRYPTO_MD_SHA512
#elif TPM_ALG_ID == TPM_ALG_SHA384
#define CRYPTO_MD_ID CRYPTO_MD_SHA384
#elif TPM_ALG_ID == TPM_ALG_SHA256
#define CRYPTO_MD_ID CRYPTO_MD_SHA256
#else
# error Invalid TPM algorithm.
#endif /* TPM_ALG_ID */
/* Running Event Log Pointer */
static uint8_t *log_ptr;
@ -245,7 +254,7 @@ void event_log_write_header(void)
int event_log_measure_and_record(uintptr_t data_base, uint32_t data_size,
uint32_t data_id)
{
unsigned char hash_data[MBEDTLS_MD_MAX_SIZE];
unsigned char hash_data[CRYPTO_MD_MAX_SIZE];
int rc;
const event_log_metadata_t *metadata_ptr = plat_metadata_ptr;
@ -257,8 +266,8 @@ int event_log_measure_and_record(uintptr_t data_base, uint32_t data_size,
assert(metadata_ptr->id != EVLOG_INVALID_ID);
/* Calculate hash */
rc = crypto_mod_calc_hash((unsigned int)MBEDTLS_MD_ID,
(void *)data_base, data_size, hash_data);
rc = crypto_mod_calc_hash(CRYPTO_MD_ID,
(void *)data_base, data_size, hash_data);
if (rc != 0) {
return rc;
}

15
drivers/measured_boot/event_log/event_log.mk
View File

@ -12,35 +12,24 @@ EVENT_LOG_LEVEL ?= 40
TPM_HASH_ALG := sha256
ifeq (${TPM_HASH_ALG}, sha512)
MBEDTLS_MD_ID := MBEDTLS_MD_SHA512
TPM_ALG_ID := TPM_ALG_SHA512
TCG_DIGEST_SIZE := 64U
else ifeq (${TPM_HASH_ALG}, sha384)
MBEDTLS_MD_ID := MBEDTLS_MD_SHA384
TPM_ALG_ID := TPM_ALG_SHA384
TCG_DIGEST_SIZE := 48U
else
MBEDTLS_MD_ID := MBEDTLS_MD_SHA256
TPM_ALG_ID := TPM_ALG_SHA256
TCG_DIGEST_SIZE := 32U
endif
endif #TPM_HASH_ALG
# Set definitions for mbed TLS library and Measured Boot driver
# Set definitions for Measured Boot driver.
$(eval $(call add_defines,\
$(sort \
MBEDTLS_MD_ID \
TPM_ALG_ID \
TCG_DIGEST_SIZE \
EVENT_LOG_LEVEL \
)))
ifeq (${HASH_ALG}, sha256)
ifneq (${TPM_HASH_ALG}, sha256)
$(eval $(call add_define,MBEDTLS_SHA512_C))
endif
endif
MEASURED_BOOT_SRC_DIR := drivers/measured_boot/event_log/
MEASURED_BOOT_SOURCES := ${MEASURED_BOOT_SRC_DIR}event_log.c \

22
include/drivers/auth/crypto_mod.h
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
* Copyright (c) 2015-2021, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@ -25,6 +25,16 @@ enum crypto_dec_algo {
CRYPTO_GCM_DECRYPT = 0
};
/* Message digest algorithm */
enum crypto_md_algo {
CRYPTO_MD_SHA256,
CRYPTO_MD_SHA384,
CRYPTO_MD_SHA512,
};
/* Maximum size as per the known stronger hash algorithm i.e.SHA512 */
#define CRYPTO_MD_MAX_SIZE 64U
/*
* Cryptographic library descriptor
*/
@ -49,8 +59,9 @@ typedef struct crypto_lib_desc_s {
#if MEASURED_BOOT
/* Calculate a hash. Return hash value */
int (*calc_hash)(unsigned int alg, void *data_ptr,
unsigned int data_len, unsigned char *output);
int (*calc_hash)(enum crypto_md_algo md_alg, void *data_ptr,
unsigned int data_len,
unsigned char output[CRYPTO_MD_MAX_SIZE]);
#endif /* MEASURED_BOOT */
/*
@ -79,8 +90,9 @@ int crypto_mod_auth_decrypt(enum crypto_dec_algo dec_algo, void *data_ptr,
unsigned int tag_len);
#if MEASURED_BOOT
int crypto_mod_calc_hash(unsigned int alg, void *data_ptr,
unsigned int data_len, unsigned char *output);
int crypto_mod_calc_hash(enum crypto_md_algo alg, void *data_ptr,
unsigned int data_len,
unsigned char output[CRYPTO_MD_MAX_SIZE]);
/* Macro to register a cryptographic library */
#define REGISTER_CRYPTO_LIB(_name, _init, _verify_signature, _verify_hash, \

15
include/drivers/auth/mbedtls/mbedtls_config.h
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2015-2020, Arm Limited. All rights reserved.
* Copyright (c) 2015-2021, Arm Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@ -71,9 +71,20 @@
#endif
#define MBEDTLS_SHA256_C
#if (TF_MBEDTLS_HASH_ALG_ID != TF_MBEDTLS_SHA256)
/*
* If either Trusted Boot or Measured Boot require a stronger algorithm than
* SHA-256, pull in SHA-512 support.
*/
#if (TF_MBEDTLS_HASH_ALG_ID != TF_MBEDTLS_SHA256) /* TBB hash algo */
#define MBEDTLS_SHA512_C
#else
/* TBB uses SHA-256, what about measured boot? */
#if defined(TF_MBEDTLS_TPM_HASH_ALG_ID) && \
(TF_MBEDTLS_TPM_HASH_ALG_ID != TF_MBEDTLS_SHA256)
#define MBEDTLS_SHA512_C
#endif
#endif
#define MBEDTLS_VERSION_C

14
plat/arm/common/arm_common.mk
View File

@ -389,6 +389,15 @@ ifneq (${TRUSTED_BOARD_BOOT},0)
$(eval $(call TOOL_ADD_IMG,ns_bl2u,--fwu,FWU_))
# Include Measured Boot makefile before any Crypto library makefile.
# Crypto library makefile may need default definitions of Measured Boot build
# flags present in Measured Boot makefile.
ifeq (${MEASURED_BOOT},1)
MEASURED_BOOT_MK := drivers/measured_boot/event_log/event_log.mk
$(info Including ${MEASURED_BOOT_MK})
include ${MEASURED_BOOT_MK}
endif
# We expect to locate the *.mk files under the directories specified below
ifeq (${ARM_CRYPTOCELL_INTEG},0)
CRYPTO_LIB_MK := drivers/auth/mbedtls/mbedtls_crypto.mk
@ -411,8 +420,3 @@ ifeq (${RECLAIM_INIT_CODE}, 1)
endif
endif
ifeq (${MEASURED_BOOT},1)
MEASURED_BOOT_MK := drivers/measured_boot/event_log/event_log.mk
$(info Including ${MEASURED_BOOT_MK})
include ${MEASURED_BOOT_MK}
endif