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trezor-firmware/core/embed/util/fwutils/fwutils.c
2025-05-06 16:33:36 +02:00

146 lines
3.6 KiB
C

/*
* This file is part of the Trezor project, https://trezor.io/
*
* Copyright (c) SatoshiLabs
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <trezor_bsp.h>
#include <trezor_model.h>
#include <trezor_rtl.h>
#include <sys/systask.h>
#include <util/flash.h>
#include <util/fwutils.h>
#include <util/image.h>
#include "blake2s.h"
#include "flash_area.h"
#ifdef KERNEL_MODE
#define FW_HASHING_CHUNK_SIZE 1024
typedef struct {
bool initialized;
BLAKE2S_CTX blake;
uint32_t fw_offset;
uint32_t fw_size;
} firmware_hash_context_t;
static firmware_hash_context_t g_hash_context[SYSTASK_MAX_TASKS];
int firmware_hash_start(const uint8_t* challenge, size_t challenge_len) {
firmware_hash_context_t* ctx = &g_hash_context[systask_id(systask_active())];
int err;
if (challenge_len != 0) {
err = blake2s_InitKey(&ctx->blake, BLAKE2S_DIGEST_LENGTH, challenge,
challenge_len);
} else {
err = blake2s_Init(&ctx->blake, BLAKE2S_DIGEST_LENGTH);
}
if (err != 0) {
return -1;
}
ctx->fw_offset = 0;
ctx->fw_size = flash_area_get_size(&FIRMWARE_AREA);
ensure((ctx->fw_size % FW_HASHING_CHUNK_SIZE == 0) * sectrue,
"Cannot compute FW hash.");
ctx->initialized = true;
return 0;
}
int firmware_hash_continue(uint8_t* hash, size_t hash_len) {
firmware_hash_context_t* ctx = &g_hash_context[systask_id(systask_active())];
memset(hash, 0, hash_len);
if (!ctx->initialized) {
return -1;
}
int n_chunks = 128;
while (ctx->fw_offset < ctx->fw_size && n_chunks > 0) {
const void* chunk_ptr = flash_area_get_address(
&FIRMWARE_AREA, ctx->fw_offset, FW_HASHING_CHUNK_SIZE);
int err = blake2s_Update(&ctx->blake, chunk_ptr, FW_HASHING_CHUNK_SIZE);
if (err != 0) {
ctx->initialized = false;
return -1;
}
ctx->fw_offset += FW_HASHING_CHUNK_SIZE;
--n_chunks;
}
if (ctx->fw_offset >= ctx->fw_size) {
ctx->initialized = false;
int err = blake2s_Final(&ctx->blake, hash, hash_len);
if (err != 0) {
return -1;
}
}
return (100 * ctx->fw_offset) / ctx->fw_size;
}
secbool firmware_get_vendor(char* buff, size_t buff_size) {
const void* data = flash_area_get_address(&FIRMWARE_AREA, 0, 0);
vendor_header vhdr = {0};
memset(buff, 0, buff_size);
if (data == NULL || sectrue != read_vendor_header(data, &vhdr)) {
return secfalse;
}
if (buff_size < vhdr.vstr_len + 1) {
return secfalse;
}
memcpy(buff, vhdr.vstr, vhdr.vstr_len);
return sectrue;
}
void firmware_invalidate_header(void) {
#ifdef STM32U5
// on stm32u5, we need to disable the instruction cache before erasing the
// firmware - otherwise, the write check will fail
ICACHE->CR &= ~ICACHE_CR_EN;
#endif
// erase start of the firmware (metadata) -> invalidate FW
ensure(flash_unlock_write(), NULL);
for (int i = 0; i < (1024 / FLASH_BLOCK_SIZE); i++) {
flash_block_t data = {0};
ensure(flash_area_write_block(&FIRMWARE_AREA, i * FLASH_BLOCK_SIZE, data),
NULL);
}
ensure(flash_lock_write(), NULL);
}
#endif // KERNEL_MODE