zephyr/subsys/storage/flash_map/flash_map_integrity.c

118 lines
2.9 KiB
C

/*
* Copyright (c) 2017-2021 Nordic Semiconductor ASA
* Copyright (c) 2015 Runtime Inc
* Copyright (c) 2017 Linaro Ltd
* Copyright (c) 2020 Gerson Fernando Budke <nandojve@gmail.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <errno.h>
#include <zephyr/types.h>
#include <stddef.h>
#include <string.h>
#include <sys/types.h>
#include <zephyr/device.h>
#include <zephyr/storage/flash_map.h>
#include "flash_map_priv.h"
#include <zephyr/drivers/flash.h>
#include <zephyr/init.h>
#define SHA256_DIGEST_SIZE 32
#if defined(CONFIG_FLASH_AREA_CHECK_INTEGRITY_PSA)
#include <psa/crypto.h>
#define SUCCESS_VALUE PSA_SUCCESS
#else
#include <mbedtls/sha256.h>
#define SUCCESS_VALUE 0
#endif
int flash_area_check_int_sha256(const struct flash_area *fa,
const struct flash_area_check *fac)
{
unsigned char hash[SHA256_DIGEST_SIZE];
#if defined(CONFIG_FLASH_AREA_CHECK_INTEGRITY_PSA)
psa_hash_operation_t hash_ctx;
#else /* CONFIG_FLASH_AREA_CHECK_INTEGRITY_MBEDTLS */
mbedtls_sha256_context hash_ctx;
#endif
int to_read;
int pos;
int rc;
if (fa == NULL || fac == NULL || fac->match == NULL ||
fac->rbuf == NULL || fac->clen == 0 || fac->rblen == 0) {
return -EINVAL;
}
if (!is_in_flash_area_bounds(fa, fac->off, fac->clen)) {
return -EINVAL;
}
#if defined(CONFIG_FLASH_AREA_CHECK_INTEGRITY_PSA)
hash_ctx = psa_hash_operation_init();
rc = psa_hash_setup(&hash_ctx, PSA_ALG_SHA_256);
#else /* CONFIG_FLASH_AREA_CHECK_INTEGRITY_MBEDTLS */
mbedtls_sha256_init(&hash_ctx);
rc = mbedtls_sha256_starts(&hash_ctx, false);
#endif
if (rc != SUCCESS_VALUE) {
return -ESRCH;
}
to_read = fac->rblen;
for (pos = 0; pos < fac->clen; pos += to_read) {
if (pos + to_read > fac->clen) {
to_read = fac->clen - pos;
}
rc = flash_read(fa->fa_dev, (fa->fa_off + fac->off + pos),
fac->rbuf, to_read);
if (rc != 0) {
goto error;
}
#if defined(CONFIG_FLASH_AREA_CHECK_INTEGRITY_PSA)
rc = psa_hash_update(&hash_ctx, fac->rbuf, to_read);
#else /* CONFIG_FLASH_AREA_CHECK_INTEGRITY_MBEDTLS */
rc = mbedtls_sha256_update(&hash_ctx, fac->rbuf, to_read);
#endif
if (rc != SUCCESS_VALUE) {
rc = -ESRCH;
goto error;
}
}
#if defined(CONFIG_FLASH_AREA_CHECK_INTEGRITY_PSA)
size_t hash_len;
rc = psa_hash_finish(&hash_ctx, hash, sizeof(hash), &hash_len);
#else /* CONFIG_FLASH_AREA_CHECK_INTEGRITY_MBEDTLS */
rc = mbedtls_sha256_finish(&hash_ctx, hash);
#endif
if (rc != SUCCESS_VALUE) {
rc = -ESRCH;
goto error;
}
if (memcmp(hash, fac->match, SHA256_DIGEST_SIZE)) {
#if defined(CONFIG_FLASH_AREA_CHECK_INTEGRITY_PSA)
/* The operation has already been terminated. */
return -EILSEQ;
#else /* CONFIG_FLASH_AREA_CHECK_INTEGRITY_MBEDTLS */
rc = -EILSEQ;
goto error;
#endif
}
error:
#if defined(CONFIG_FLASH_AREA_CHECK_INTEGRITY_PSA)
psa_hash_abort(&hash_ctx);
#else /* CONFIG_FLASH_AREA_CHECK_INTEGRITY_MBEDTLS */
mbedtls_sha256_free(&hash_ctx);
#endif
return rc;
}