Merge "fix(arm): add extra hash config to validate ROTPK" into integration

plat/arm/board/fvp_r/platform.mk

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2021, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2021-2024, Arm Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -25,7 +25,7 @@ FVP_R_INTERCONNECT_SOURCES	:= 	drivers/arm/cci/cci.c
 include plat/arm/board/common/board_common.mk
 include plat/arm/common/arm_common.mk
 
-PLAT_INCLUDES		:=	-Iplat/arm/board/fvp_r/include
+PLAT_INCLUDES		+=	-Iplat/arm/board/fvp_r/include
 
 FVP_R_BL_COMMON_SOURCES	:=	plat/arm/board/fvp_r/fvp_r_common.c		\
 				plat/arm/board/fvp_r/fvp_r_context_mgmt.c	\

plat/arm/board/tc/plat_tc_mbedtls_config.h

@@ -21,6 +21,20 @@
 #endif
 #endif /* TF_MBEDTLS_HEAP_SIZE */
 
+/**
+ * On Arm TC platforms, the ROTPK is always hashed using the SHA-256
+ * algorithm.
+ * TODO: Update to hash the ROTPK with the selected HASH_ALG to avoid
+ * the need for explicitly enabling the SHA-256 configuration in mbedTLS.
+ */
+#define MBEDTLS_SHA256_C
+
+/*
+ * Use an implementation of SHA-256 with a smaller memory footprint
+ * but reduced speed.
+ */
+#define MBEDTLS_SHA256_SMALLER
+
 #define MBEDTLS_PSA_CRYPTO_C
 #define MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG
 #define MBEDTLS_ECP_C

plat/arm/common/arm_common.mk

@@ -119,10 +119,6 @@ ifeq (${ARM_LINUX_KERNEL_AS_BL33},1)
   endif
 endif
 
-# Use an implementation of SHA-256 with a smaller memory footprint but reduced
-# speed.
-$(eval $(call add_define,MBEDTLS_SHA256_SMALLER))
-
 # Add the build options to pack Trusted OS Extra1 and Trusted OS Extra2 images
 # in the FIP if the platform requires.
 ifneq ($(BL32_EXTRA1),)
@@ -364,6 +360,17 @@ ifeq (${DRTM_SUPPORT},1)
 BL31_SOURCES            +=	plat/arm/common/arm_err.c
 endif
 
+ifneq ($(filter 1,${MEASURED_BOOT} ${TRUSTED_BOARD_BOOT} ${DRTM_SUPPORT}),)
+    PLAT_INCLUDES		+=	-Iplat/arm/common	\
+					-Iinclude/drivers/auth/mbedtls
+    # Specify mbed TLS configuration file
+    ifeq (${PSA_CRYPTO},1)
+      MBEDTLS_CONFIG_FILE	?=	"<plat_arm_psa_mbedtls_config.h>"
+    else
+      MBEDTLS_CONFIG_FILE	?=	"<plat_arm_mbedtls_config.h>"
+    endif
+endif
+
 ifneq (${TRUSTED_BOARD_BOOT},0)
 
     # Include common TBB sources

plat/arm/common/plat_arm_mbedtls_config.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2024, Arm Ltd. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef PLAT_ARM_MBEDTLS_CONFIG_H
+#define PLAT_ARM_MBEDTLS_CONFIG_H
+
+#include <mbedtls_config-3.h>
+
+/**
+ * On Arm platforms, the ROTPK is always hashed using the SHA-256
+ * algorithm.
+ * TODO: Update to hash the ROTPK with the selected HASH_ALG to avoid
+ * the need for explicitly enabling the SHA-256 configuration in mbedTLS.
+ */
+#define MBEDTLS_SHA256_C
+
+/*
+ * Use an implementation of SHA-256 with a smaller memory footprint
+ * but reduced speed.
+ */
+#define MBEDTLS_SHA256_SMALLER
+
+#endif /* PLAT_ARM_MBEDTLS_CONFIG_H */

plat/arm/common/plat_arm_psa_mbedtls_config.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2024, Arm Ltd. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef PLAT_ARM_PSA_MBEDTLS_CONFIG_H
+#define PLAT_ARM_PSA_MBEDTLS_CONFIG_H
+
+#include "plat_arm_mbedtls_config.h"
+
+#define MBEDTLS_PSA_CRYPTO_C
+#define MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS
+
+/*
+ * Using PSA crypto API requires an RNG right now. If we don't define the macro
+ * below then we get build errors.
+ *
+ * This is a functionality gap in mbedTLS. The technical limitation is that
+ * psa_crypto_init() is all-or-nothing, and fixing that would require separate
+ * initialization of the keystore, the RNG, etc.
+ *
+ * By defining MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG, we pretend using an external
+ * RNG. As a result, the PSA crypto init code does nothing when it comes to
+ * initializing the RNG, as we are supposed to take care of that ourselves.
+ */
+#define MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG
+
+#endif /* PLAT_ARM_PSA_MBEDTLS_CONFIG_H */