void bootloader_sha256_finish(bootloader_sha256_handle_t handle, uint8_t *digest)
{
assert(handle != NULL);
if (digest == NULL) {
return; // We'd free resources here, but there are none to free
}
uint32_t data_words = words_hashed;
// Pad to a 55 byte long block loaded in the engine
// (leaving 1 byte 0x80 plus variable padding plus 8 bytes of length,
// to fill a 64 byte block.)
int block_bytes = (words_hashed % BLOCK_WORDS) * 4;
int pad_bytes = 55 - block_bytes;
if (pad_bytes < 0) {
pad_bytes += 64;
}
static const uint8_t padding[64] = { 0x80, 0, };
pad_bytes += 5; // 1 byte for 0x80 plus first 4 bytes of the 64-bit length
assert(pad_bytes % 4 == 0); // should be, as (block_bytes % 4 == 0)
bootloader_sha256_data(handle, padding, pad_bytes);
assert(words_hashed % BLOCK_WORDS == 60/4); // 32-bits left in block
// Calculate 32-bit length for final 32 bits of data
uint32_t bit_count = __builtin_bswap32( data_words * 32 );
bootloader_sha256_data(handle, &bit_count, sizeof(bit_count));
assert(words_hashed % BLOCK_WORDS == 0);
while(REG_READ(SHA_256_BUSY_REG) == 1) { }
REG_WRITE(SHA_256_LOAD_REG, 1);
while(REG_READ(SHA_256_BUSY_REG) == 1) { }
uint32_t *digest_words = (uint32_t *)digest;
uint32_t *sha_text_reg = (uint32_t *)(SHA_TEXT_BASE);
for (int i = 0; i < DIGEST_WORDS; i++) {
digest_words[i] = __builtin_bswap32(sha_text_reg[i]);
}
asm volatile ("memw");
}
esp_err_t bootloader_common_get_sha256_of_partition (uint32_t address, uint32_t size, int type, uint8_t *out_sha_256)
{
if (out_sha_256 == NULL || size == 0) {
return ESP_ERR_INVALID_ARG;
}
if (type == PART_TYPE_APP) {
const esp_partition_pos_t partition_pos = {
.offset = address,
.size = size,
};
esp_image_metadata_t data;
// Function esp_image_verify() verifies and fills the structure data.
// here important to get: image_digest, image_len, hash_appended.
if (esp_image_verify(ESP_IMAGE_VERIFY_SILENT, &partition_pos, &data) != ESP_OK) {
return ESP_ERR_IMAGE_INVALID;
}
if (data.image.hash_appended) {
memcpy(out_sha_256, data.image_digest, ESP_PARTITION_HASH_LEN);
return ESP_OK;
}
// If image doesn't have a appended hash then hash calculates for entire image.
size = data.image_len;
}
// If image is type by data then hash is calculated for entire image.
const void *partition_bin = bootloader_mmap(address, size);
if (partition_bin == NULL) {
ESP_LOGE(TAG, "bootloader_mmap(0x%x, 0x%x) failed", address, size);
return ESP_FAIL;
}
bootloader_sha256_handle_t sha_handle = bootloader_sha256_start();
if (sha_handle == NULL) {
bootloader_munmap(partition_bin);
return ESP_ERR_NO_MEM;
}
bootloader_sha256_data(sha_handle, partition_bin, size);
bootloader_sha256_finish(sha_handle, out_sha_256);
bootloader_munmap(partition_bin);
return ESP_OK;
}