esp-idf/components/esp_rom/include/esp32s2/rom/secure_boot.h

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4.6 KiB
C

// Copyright 2020 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef _ROM_SECURE_BOOT_H_
#define _ROM_SECURE_BOOT_H_
#include <stdint.h>
#include "rsa_pss.h"
#ifdef __cplusplus
extern "C" {
#endif
struct ets_secure_boot_sig_block;
struct ets_secure_boot_signature_t;
typedef struct ets_secure_boot_sig_block ets_secure_boot_sig_block_t;
typedef struct ets_secure_boot_signature ets_secure_boot_signature_t;
typedef struct ets_secure_boot_key_digests ets_secure_boot_key_digests_t;
/* 64KB 'staging buffer' for loading the verified bootloader
Comes from the "shared buffers" region (see shared_buffers.h)
The bootloader can't be safely linked into this address range
(may be possible with some cleverness.)
*/
#define SECURE_BOOT_STAGING_BUFFER_START ((uint32_t)(g_shared_buffers.secure_boot_staging_buf))
#define SECURE_BOOT_STAGING_BUFFER_SZ sizeof(g_shared_buffers.secure_boot_staging_buf)
#define SECURE_BOOT_STAGING_BUFFER_END (SECURE_BOOT_STAGING_BUFFER_START + SECURE_BOOT_STAGING_BUFFER_SZ)
/* Anti-FI measure: use full words for success/fail, instead of
0/non-zero
*/
typedef enum {
SB_SUCCESS = 0x3A5A5AA5,
SB_FAILED = 0x7533885E,
} ets_secure_boot_status_t;
/* Verify and stage-load the bootloader image
(reconfigures cache to map, loads trusted key digests from efuse,
copies the bootloader into the staging buffer.)
If allow_key_revoke is true and aggressive revoke efuse is set,
any failed signature has its associated key revoked in efuse.
If result is SB_SUCCESS, the "simple hash" of the bootloader
is copied into verified_hash.
*/
ets_secure_boot_status_t ets_secure_boot_verify_stage_bootloader(uint8_t *verified_hash, bool allow_key_revoke);
/* Verify bootloader image (reconfigures cache to map),
with key digests provided as parameters.)
Can be used to verify secure boot status before enabling
secure boot permanently.
If stage_load parameter is true, bootloader is copied into staging
buffer in RAM at the same time.
If result is SB_SUCCESS, the "simple hash" of the bootloader is
copied into verified_hash.
*/
ets_secure_boot_status_t ets_secure_boot_verify_bootloader_with_keys(uint8_t *verified_hash, const ets_secure_boot_key_digests_t *trusted_keys, bool stage_load);
/* Read key digests from efuse. Any revoked/missing digests will be
marked as NULL
*/
ETS_STATUS ets_secure_boot_read_key_digests(ets_secure_boot_key_digests_t *trusted_keys);
/* Verify supplied signature against supplied digest, using
supplied trusted key digests.
Doesn't reconfigure cache or any other hardware access except for RSA peripheral.
If result is SB_SUCCESS, the image_digest value is copied into verified_digest.
*/
ets_secure_boot_status_t ets_secure_boot_verify_signature(const ets_secure_boot_signature_t *sig, const uint8_t *image_digest, const ets_secure_boot_key_digests_t *trusted_keys, uint8_t *verified_digest);
/* Revoke a public key digest in efuse.
@param index Digest to revoke. Must be 0, 1 or 2.
*/
void ets_secure_boot_revoke_public_key_digest(int index);
#define ETS_SECURE_BOOT_V2_SIGNATURE_MAGIC 0xE7
/* Secure Boot V2 signature block
(Up to 3 in a signature sector are appended to the image)
*/
struct ets_secure_boot_sig_block {
uint8_t magic_byte;
uint8_t version;
uint8_t _reserved1;
uint8_t _reserved2;
uint8_t image_digest[32];
ets_rsa_pubkey_t key;
uint8_t signature[384];
uint32_t block_crc;
uint8_t _padding[16];
};
_Static_assert(sizeof(ets_secure_boot_sig_block_t) == 1216, "invalid sig block size");
#define SECURE_BOOT_NUM_BLOCKS 3
/* V2 Secure boot signature sector (up to 3 blocks) */
struct ets_secure_boot_signature {
ets_secure_boot_sig_block_t block[SECURE_BOOT_NUM_BLOCKS];
uint8_t _padding[4096 - (sizeof(ets_secure_boot_sig_block_t) * SECURE_BOOT_NUM_BLOCKS)];
};
_Static_assert(sizeof(ets_secure_boot_signature_t) == 4096, "invalid sig sector size");
#define MAX_KEY_DIGESTS 3
struct ets_secure_boot_key_digests {
const void *key_digests[MAX_KEY_DIGESTS];
bool allow_key_revoke;
};
#ifdef __cplusplus
}
#endif
#endif /* _ROM_SECURE_BOOT_H_ */