esp-idf/components/bootloader_support/src/secure_boot_v1/secure_boot_signatures_boot...

93 wiersze
3.2 KiB
C

/*
* SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include "sdkconfig.h"
#include "bootloader_flash_priv.h"
#include "bootloader_sha.h"
#include "bootloader_utility.h"
#include "esp_log.h"
#include "esp_image_format.h"
#include "esp_secure_boot.h"
#include "spi_flash_mmap.h"
#include "esp_fault.h"
#include "esp32/rom/sha.h"
#include "uECC_verify_antifault.h"
#include <sys/param.h>
#include <string.h>
static const char *TAG = "secure_boot";
#ifdef CONFIG_SECURE_SIGNED_APPS_ECDSA_SCHEME
extern const uint8_t signature_verification_key_start[] asm("_binary_signature_verification_key_bin_start");
extern const uint8_t signature_verification_key_end[] asm("_binary_signature_verification_key_bin_end");
#define SIGNATURE_VERIFICATION_KEYLEN 64
esp_err_t esp_secure_boot_verify_signature(uint32_t src_addr, uint32_t length)
{
uint8_t digest[ESP_SECURE_BOOT_DIGEST_LEN];
uint8_t verified_digest[ESP_SECURE_BOOT_DIGEST_LEN] = { 0 }; /* ignored in this function */
const esp_secure_boot_sig_block_t *sigblock;
ESP_LOGD(TAG, "verifying signature src_addr 0x%" PRIx32 " length 0x%" PRIx32, src_addr, length);
esp_err_t err = bootloader_sha256_flash_contents(src_addr, length, digest);
if (err != ESP_OK) {
return err;
}
// Map the signature block
sigblock = (const esp_secure_boot_sig_block_t *) bootloader_mmap(src_addr + length, sizeof(esp_secure_boot_sig_block_t));
if(!sigblock) {
ESP_LOGE(TAG, "bootloader_mmap(0x%" PRIx32 ", 0x%x) failed", src_addr + length, sizeof(esp_secure_boot_sig_block_t));
return ESP_FAIL;
}
// Verify the signature
err = esp_secure_boot_verify_ecdsa_signature_block(sigblock, digest, verified_digest);
// Unmap
bootloader_munmap(sigblock);
return err;
}
esp_err_t esp_secure_boot_verify_signature_block(const esp_secure_boot_sig_block_t *sig_block, const uint8_t *image_digest)
{
uint8_t verified_digest[ESP_SECURE_BOOT_DIGEST_LEN] = { 0 };
return esp_secure_boot_verify_ecdsa_signature_block(sig_block, image_digest, verified_digest);
}
esp_err_t esp_secure_boot_verify_ecdsa_signature_block(const esp_secure_boot_sig_block_t *sig_block, const uint8_t *image_digest, uint8_t *verified_digest)
{
ptrdiff_t keylen;
keylen = signature_verification_key_end - signature_verification_key_start;
if (keylen != SIGNATURE_VERIFICATION_KEYLEN) {
ESP_LOGE(TAG, "Embedded public verification key has wrong length %d", keylen);
return ESP_FAIL;
}
if (sig_block->version != 0) {
ESP_LOGE(TAG, "image has invalid signature version field 0x%08" PRIx32 " (image without a signature?)", sig_block->version);
return ESP_FAIL;
}
ESP_LOGD(TAG, "Verifying secure boot signature");
bool is_valid;
is_valid = uECC_verify_antifault(signature_verification_key_start,
image_digest,
ESP_SECURE_BOOT_DIGEST_LEN,
sig_block->signature,
uECC_secp256r1(),
verified_digest);
ESP_LOGD(TAG, "Verification result %d", is_valid);
return is_valid ? ESP_OK : ESP_ERR_IMAGE_INVALID;
}
#endif // CONFIG_SECURE_SIGNED_APPS_ECDSA_SCHEME