esp-idf/components/efuse/src/esp_efuse_api_key_esp32xx.c

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14 KiB
C

/*
* SPDX-FileCopyrightText: 2017-2021 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include "esp_efuse.h"
#include "esp_efuse_utility.h"
#include "soc/efuse_periph.h"
#include "assert.h"
#include "sdkconfig.h"
#include "esp_efuse_table.h"
const static char *TAG = "efuse";
/**
* @brief Keys and their attributes are packed into a structure
*/
typedef struct {
const esp_efuse_desc_t** key; /**< Key */
const esp_efuse_desc_t** keypurpose; /**< Key purpose */
const esp_efuse_desc_t** key_rd_dis; /**< Read protection of a key */
const esp_efuse_desc_t** key_wr_dis; /**< Write protection of a key*/
const esp_efuse_desc_t** keypurpose_wr_dis; /**< Write protection of a key purpose*/
} esp_efuse_keys_t;
typedef struct {
const esp_efuse_desc_t** revoke;
const esp_efuse_desc_t** revoke_wr_dis;
const esp_efuse_purpose_t digest_purpose;
} esp_efuse_revokes_t;
const esp_efuse_keys_t s_table[EFUSE_BLK_KEY_MAX - EFUSE_BLK_KEY0] = {
#if CONFIG_IDF_TARGET_ESP8684
{ESP_EFUSE_KEY0, NULL, ESP_EFUSE_RD_DIS_KEY0, ESP_EFUSE_WR_DIS_KEY0, NULL},
#else
{ESP_EFUSE_KEY0, ESP_EFUSE_KEY_PURPOSE_0, ESP_EFUSE_RD_DIS_KEY0, ESP_EFUSE_WR_DIS_KEY0, ESP_EFUSE_WR_DIS_KEY0_PURPOSE},
{ESP_EFUSE_KEY1, ESP_EFUSE_KEY_PURPOSE_1, ESP_EFUSE_RD_DIS_KEY1, ESP_EFUSE_WR_DIS_KEY1, ESP_EFUSE_WR_DIS_KEY1_PURPOSE},
{ESP_EFUSE_KEY2, ESP_EFUSE_KEY_PURPOSE_2, ESP_EFUSE_RD_DIS_KEY2, ESP_EFUSE_WR_DIS_KEY2, ESP_EFUSE_WR_DIS_KEY2_PURPOSE},
{ESP_EFUSE_KEY3, ESP_EFUSE_KEY_PURPOSE_3, ESP_EFUSE_RD_DIS_KEY3, ESP_EFUSE_WR_DIS_KEY3, ESP_EFUSE_WR_DIS_KEY3_PURPOSE},
{ESP_EFUSE_KEY4, ESP_EFUSE_KEY_PURPOSE_4, ESP_EFUSE_RD_DIS_KEY4, ESP_EFUSE_WR_DIS_KEY4, ESP_EFUSE_WR_DIS_KEY4_PURPOSE},
{ESP_EFUSE_KEY5, ESP_EFUSE_KEY_PURPOSE_5, ESP_EFUSE_RD_DIS_KEY5, ESP_EFUSE_WR_DIS_KEY5, ESP_EFUSE_WR_DIS_KEY5_PURPOSE},
#if 0
{ESP_EFUSE_KEY6, ESP_EFUSE_KEY_PURPOSE_6, ESP_EFUSE_RD_DIS_KEY6, ESP_EFUSE_WR_DIS_KEY6, ESP_EFUSE_WR_DIS_KEY6_PURPOSE},
#endif
#endif //#if CONFIG_IDF_TARGET_ESP8684
};
#if SOC_SUPPORT_SECURE_BOOT_REVOKE_KEY
const esp_efuse_revokes_t s_revoke_table[] = {
{ESP_EFUSE_SECURE_BOOT_KEY_REVOKE0, ESP_EFUSE_WR_DIS_SECURE_BOOT_KEY_REVOKE0, ESP_EFUSE_KEY_PURPOSE_SECURE_BOOT_DIGEST0},
{ESP_EFUSE_SECURE_BOOT_KEY_REVOKE1, ESP_EFUSE_WR_DIS_SECURE_BOOT_KEY_REVOKE1, ESP_EFUSE_KEY_PURPOSE_SECURE_BOOT_DIGEST1},
{ESP_EFUSE_SECURE_BOOT_KEY_REVOKE2, ESP_EFUSE_WR_DIS_SECURE_BOOT_KEY_REVOKE2, ESP_EFUSE_KEY_PURPOSE_SECURE_BOOT_DIGEST2},
};
#endif
bool esp_efuse_block_is_empty(esp_efuse_block_t block)
{
const unsigned blk_len_bit = 256;
uint32_t key[8];
esp_err_t err = esp_efuse_read_block(block, &key, 0, blk_len_bit);
if (err != ESP_OK) {
return false;
}
unsigned zeros = 0;
for (unsigned i = 0; i < blk_len_bit / 32; ++i) {
if (key[i] == 0) {
++zeros;
}
}
if (zeros == blk_len_bit / 32) {
return true;
}
return false;
}
// Sets a write protection for the whole block.
esp_err_t esp_efuse_set_write_protect(esp_efuse_block_t blk)
{
#if !CONFIG_IDF_TARGET_ESP8684
if (blk == EFUSE_BLK1) {
return esp_efuse_write_field_cnt(ESP_EFUSE_WR_DIS_BLK1, 1);
} else if (blk == EFUSE_BLK2) {
return esp_efuse_write_field_cnt(ESP_EFUSE_WR_DIS_SYS_DATA_PART1, 1);
} else if (blk == EFUSE_BLK3) {
return esp_efuse_write_field_cnt(ESP_EFUSE_WR_DIS_USER_DATA, 1);
} else if (blk == EFUSE_BLK10) {
return esp_efuse_write_field_cnt(ESP_EFUSE_WR_DIS_SYS_DATA_PART2, 1);
} else if (blk >= EFUSE_BLK_KEY0 && blk < EFUSE_BLK_KEY_MAX) {
unsigned idx = blk - EFUSE_BLK_KEY0;
return esp_efuse_write_field_cnt(s_table[idx].key_wr_dis, 1);
}
#endif
return ESP_ERR_NOT_SUPPORTED; // IDF-3818
}
// read protect for blk.
esp_err_t esp_efuse_set_read_protect(esp_efuse_block_t blk)
{
if (blk >= EFUSE_BLK_KEY0 && blk < EFUSE_BLK_KEY_MAX) {
unsigned idx = blk - EFUSE_BLK_KEY0;
return esp_efuse_write_field_cnt(s_table[idx].key_rd_dis, 1);
}
#if !CONFIG_IDF_TARGET_ESP8684 // IDF-3818
else if (blk == EFUSE_BLK10) {
return esp_efuse_write_field_cnt(ESP_EFUSE_RD_DIS_SYS_DATA_PART2, 1);
}
#endif
return ESP_ERR_NOT_SUPPORTED;
}
// get efuse coding_scheme.
esp_efuse_coding_scheme_t esp_efuse_get_coding_scheme(esp_efuse_block_t blk)
{
esp_efuse_coding_scheme_t scheme;
if (blk == EFUSE_BLK0) {
scheme = EFUSE_CODING_SCHEME_NONE;
} else {
scheme = EFUSE_CODING_SCHEME_RS;
}
return scheme;
}
const esp_efuse_desc_t **esp_efuse_get_purpose_field(esp_efuse_block_t block)
{
if (block < EFUSE_BLK_KEY0 || block >= EFUSE_BLK_KEY_MAX) {
return NULL;
}
unsigned idx = block - EFUSE_BLK_KEY0;
return s_table[idx].keypurpose;
}
const esp_efuse_desc_t** esp_efuse_get_key(esp_efuse_block_t block)
{
if (block < EFUSE_BLK_KEY0 || block >= EFUSE_BLK_KEY_MAX) {
return NULL;
}
unsigned idx = block - EFUSE_BLK_KEY0;
return s_table[idx].key;
}
bool esp_efuse_get_key_dis_read(esp_efuse_block_t block)
{
assert(block >= EFUSE_BLK_KEY0 && block < EFUSE_BLK_KEY_MAX);
unsigned idx = block - EFUSE_BLK_KEY0;
return esp_efuse_read_field_bit(s_table[idx].key_rd_dis);
}
esp_err_t esp_efuse_set_key_dis_read(esp_efuse_block_t block)
{
if (block < EFUSE_BLK_KEY0 || block >= EFUSE_BLK_KEY_MAX) {
return ESP_ERR_INVALID_ARG;
}
unsigned idx = block - EFUSE_BLK_KEY0;
return esp_efuse_write_field_bit(s_table[idx].key_rd_dis);
}
bool esp_efuse_get_key_dis_write(esp_efuse_block_t block)
{
assert(block >= EFUSE_BLK_KEY0 && block < EFUSE_BLK_KEY_MAX);
unsigned idx = block - EFUSE_BLK_KEY0;
return esp_efuse_read_field_bit(s_table[idx].key_wr_dis);
}
esp_err_t esp_efuse_set_key_dis_write(esp_efuse_block_t block)
{
if (block < EFUSE_BLK_KEY0 || block >= EFUSE_BLK_KEY_MAX) {
return ESP_ERR_INVALID_ARG;
}
unsigned idx = block - EFUSE_BLK_KEY0;
return esp_efuse_write_field_bit(s_table[idx].key_wr_dis);
}
#if !CONFIG_IDF_TARGET_ESP8684 // cause esp8684 efuse has no purpose region
esp_efuse_purpose_t esp_efuse_get_key_purpose(esp_efuse_block_t block)
{
if (block < EFUSE_BLK_KEY0 || block >= EFUSE_BLK_KEY_MAX) {
return ESP_EFUSE_KEY_PURPOSE_MAX;
}
unsigned idx = block - EFUSE_BLK_KEY0;
uint8_t value = 0;
esp_err_t err = esp_efuse_read_field_blob(s_table[idx].keypurpose, &value, s_table[idx].keypurpose[0]->bit_count);
if (err != ESP_OK) {
return ESP_EFUSE_KEY_PURPOSE_MAX;
}
return value;
}
esp_err_t esp_efuse_set_key_purpose(esp_efuse_block_t block, esp_efuse_purpose_t purpose)
{
if (block < EFUSE_BLK_KEY0 || block >= EFUSE_BLK_KEY_MAX) {
return ESP_ERR_INVALID_ARG;
}
unsigned idx = block - EFUSE_BLK_KEY0;
return esp_efuse_write_field_blob(s_table[idx].keypurpose, &purpose, s_table[idx].keypurpose[0]->bit_count);
}
#endif //CONFIG_IDF_TARGET_ESP8684
bool esp_efuse_get_keypurpose_dis_write(esp_efuse_block_t block)
{
assert(block >= EFUSE_BLK_KEY0 && block < EFUSE_BLK_KEY_MAX);
unsigned idx = block - EFUSE_BLK_KEY0;
return esp_efuse_read_field_bit(s_table[idx].keypurpose_wr_dis);
}
esp_err_t esp_efuse_set_keypurpose_dis_write(esp_efuse_block_t block)
{
if (block < EFUSE_BLK_KEY0 || block >= EFUSE_BLK_KEY_MAX) {
return ESP_ERR_INVALID_ARG;
}
unsigned idx = block - EFUSE_BLK_KEY0;
return esp_efuse_write_field_bit(s_table[idx].keypurpose_wr_dis);
}
bool esp_efuse_find_purpose(esp_efuse_purpose_t purpose, esp_efuse_block_t *block)
{
esp_efuse_block_t dummy;
if (block == NULL) {
block = &dummy;
}
for (esp_efuse_block_t b = EFUSE_BLK_KEY0; b < EFUSE_BLK_KEY_MAX; b++) {
if (esp_efuse_get_key_purpose(b) == purpose) {
*block = b;
return true;
}
}
return false;
}
esp_efuse_block_t esp_efuse_find_unused_key_block(void)
{
for (esp_efuse_block_t b = EFUSE_BLK_KEY0; b < EFUSE_BLK_KEY_MAX; b++) {
if (esp_efuse_key_block_unused(b)) {
return b;
}
}
return EFUSE_BLK_KEY_MAX; // nothing
}
unsigned esp_efuse_count_unused_key_blocks(void)
{
unsigned r = 0;
for (esp_efuse_block_t b = EFUSE_BLK_KEY0; b < EFUSE_BLK_KEY_MAX; b++) {
if (esp_efuse_key_block_unused(b)) {
r++;
}
}
return r;
}
bool esp_efuse_key_block_unused(esp_efuse_block_t block)
{
if (block < EFUSE_BLK_KEY0 || block >= EFUSE_BLK_KEY_MAX) {
return false; // Not a key block
}
if (
#if !CONFIG_IDF_TARGET_ESP8684
esp_efuse_get_key_purpose(block) != ESP_EFUSE_KEY_PURPOSE_USER ||
esp_efuse_get_keypurpose_dis_write(block) ||
#endif
esp_efuse_get_key_dis_read(block) ||
esp_efuse_get_key_dis_write(block)) {
return false; // Block in use!
}
if (!esp_efuse_block_is_empty(block)) {
return false; // Block in use!
}
return true; // Unused
}
esp_err_t esp_efuse_write_key(esp_efuse_block_t block, esp_efuse_purpose_t purpose, const void *key, size_t key_size_bytes)
{
esp_err_t err = ESP_OK;
#if CONFIG_IDF_TARGET_ESP8684
if (block != EFUSE_BLK_KEY0) {
return ESP_ERR_INVALID_ARG;
}
#else
if (block < EFUSE_BLK_KEY0 || block >= EFUSE_BLK_KEY_MAX || key_size_bytes > 32 || purpose >= ESP_EFUSE_KEY_PURPOSE_MAX) {
return ESP_ERR_INVALID_ARG;
}
#endif
esp_efuse_batch_write_begin();
if (!esp_efuse_key_block_unused(block)) {
err = ESP_ERR_INVALID_STATE;
} else {
unsigned idx = block - EFUSE_BLK_KEY0;
ESP_EFUSE_CHK(esp_efuse_write_field_blob(s_table[idx].key, key, key_size_bytes * 8));
ESP_EFUSE_CHK(esp_efuse_set_key_dis_write(block));
#if !CONFIG_IDF_TARGET_ESP8684
if (purpose == ESP_EFUSE_KEY_PURPOSE_XTS_AES_128_KEY ||
#ifdef SOC_FLASH_ENCRYPTION_XTS_AES_256
purpose == ESP_EFUSE_KEY_PURPOSE_XTS_AES_256_KEY_1 ||
purpose == ESP_EFUSE_KEY_PURPOSE_XTS_AES_256_KEY_2 ||
#endif //#ifdef SOC_EFUSE_SUPPORT_XTS_AES_256_KEYS
purpose == ESP_EFUSE_KEY_PURPOSE_HMAC_DOWN_ALL ||
purpose == ESP_EFUSE_KEY_PURPOSE_HMAC_DOWN_JTAG ||
purpose == ESP_EFUSE_KEY_PURPOSE_HMAC_DOWN_DIGITAL_SIGNATURE ||
purpose == ESP_EFUSE_KEY_PURPOSE_HMAC_UP) {
ESP_EFUSE_CHK(esp_efuse_set_key_dis_read(block));
}
ESP_EFUSE_CHK(esp_efuse_set_key_purpose(block, purpose));
ESP_EFUSE_CHK(esp_efuse_set_keypurpose_dis_write(block));
#endif //#if !CONFIG_IDF_TARGET_ESP8684
return esp_efuse_batch_write_commit();
}
err_exit:
esp_efuse_batch_write_cancel();
return err;
}
esp_err_t esp_efuse_write_keys(const esp_efuse_purpose_t purposes[], uint8_t keys[][32], unsigned number_of_keys)
{
esp_err_t err = ESP_OK;
if (number_of_keys == 0 || number_of_keys > (EFUSE_BLK_KEY_MAX - EFUSE_BLK_KEY0) || keys == NULL || purposes == NULL) {
return ESP_ERR_INVALID_ARG;
}
esp_efuse_purpose_t purpose = 0;
esp_efuse_block_t block = EFUSE_BLK_KEY0;
esp_efuse_batch_write_begin();
unsigned unused_keys = esp_efuse_count_unused_key_blocks();
if (number_of_keys > unused_keys) {
ESP_LOGE(TAG, "Not enough unused key blocks available. Required %d, was %d", number_of_keys, unused_keys);
err = ESP_ERR_NOT_ENOUGH_UNUSED_KEY_BLOCKS;
} else {
for (int i_key = 0; (block < EFUSE_BLK_KEY_MAX) && (i_key < number_of_keys); block++) {
if (esp_efuse_key_block_unused(block)) {
purpose = purposes[i_key];
ESP_LOGI(TAG, "Writing EFUSE_BLK_KEY%d with purpose %d", block - EFUSE_BLK_KEY0, purpose);
ESP_EFUSE_CHK(esp_efuse_write_key(block, purpose, keys[i_key], 32));
i_key++;
}
}
return esp_efuse_batch_write_commit();
err_exit:
ESP_LOGE(TAG, "Failed to write EFUSE_BLK_KEY%d with purpose %d. Can't continue.", block - EFUSE_BLK_KEY0, purpose);
}
esp_efuse_batch_write_cancel();
return err;
}
#if SOC_SUPPORT_SECURE_BOOT_REVOKE_KEY
bool esp_efuse_get_digest_revoke(unsigned num_digest)
{
assert(num_digest < sizeof(s_revoke_table) / sizeof(esp_efuse_revokes_t));
return esp_efuse_read_field_bit(s_revoke_table[num_digest].revoke);
}
esp_err_t esp_efuse_set_digest_revoke(unsigned num_digest)
{
if (num_digest >= sizeof(s_revoke_table) / sizeof(esp_efuse_revokes_t)) {
return ESP_ERR_INVALID_ARG;
}
return esp_efuse_write_field_bit(s_revoke_table[num_digest].revoke);
}
bool esp_efuse_get_write_protect_of_digest_revoke(unsigned num_digest)
{
assert(num_digest < sizeof(s_revoke_table) / sizeof(esp_efuse_revokes_t));
return esp_efuse_read_field_bit(s_revoke_table[num_digest].revoke_wr_dis);
}
esp_err_t esp_efuse_set_write_protect_of_digest_revoke(unsigned num_digest)
{
if (num_digest >= sizeof(s_revoke_table) / sizeof(esp_efuse_revokes_t)) {
return ESP_ERR_INVALID_ARG;
}
return esp_efuse_write_field_bit(s_revoke_table[num_digest].revoke_wr_dis);
}
esp_err_t esp_secure_boot_read_key_digests(ets_secure_boot_key_digests_t *trusted_keys)
{
bool found = false;
esp_efuse_block_t key_block;
if (trusted_keys == NULL) {
return ESP_FAIL;
}
for (unsigned i = 0; i < MAX_KEY_DIGESTS; i++) {
trusted_keys->key_digests[i] = NULL;
if (esp_efuse_get_digest_revoke(i)) {
continue;
}
// Anti-FI check that this efuse really is not revoked
assert(esp_efuse_get_digest_revoke(i) == 0);
if (!esp_efuse_find_purpose(s_revoke_table[i].digest_purpose, &key_block)) {
continue;
}
trusted_keys->key_digests[i] = (const void *)esp_efuse_utility_get_read_register_address(key_block);
found = found || (trusted_keys->key_digests[i] != NULL);
}
trusted_keys->allow_key_revoke = false;
if (!found) {
return ESP_FAIL;
}
return ESP_OK;
}
#endif //#if SOC_SUPPORT_SECURE_BOOT_REVOKE_KEY