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mirror of https://github.com/trezor/trezor-firmware.git synced 2024-10-20 06:49:14 +00:00
trezor-firmware/core/embed/bootloader_ci/messages.c
Pavol Rusnak 35d40cc164 fix(core): change logic of vendor header comparison
Previously we checked whether the current vendor header and
the new vendor header are the same by comparing the embedded keyset.

What originally looked like a good idea is not that good, because
this disallows us from ever changing the vendor header signing keys
without causing erasure of the storage during the version update.

This commit fixes that by changing the logic to comparing just the
vendor string.

Change of function names is purely cosmetic:
* vendor_keys_hash -> vendor_header_hash
* check_vendor_keys_lock -> check_vendor_header_lock
2022-01-03 14:23:58 +01:00

657 lines
21 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 <string.h>
#include <pb.h>
#include <pb_decode.h>
#include <pb_encode.h>
#include "messages.pb.h"
#include "common.h"
#include "flash.h"
#include "image.h"
#include "secbool.h"
#include "usb.h"
#include "version.h"
#include "bootui.h"
#include "messages.h"
#include "memzero.h"
#define MSG_HEADER1_LEN 9
#define MSG_HEADER2_LEN 1
secbool msg_parse_header(const uint8_t *buf, uint16_t *msg_id,
uint32_t *msg_size) {
if (buf[0] != '?' || buf[1] != '#' || buf[2] != '#') {
return secfalse;
}
*msg_id = (buf[3] << 8) + buf[4];
*msg_size = (buf[5] << 24) + (buf[6] << 16) + (buf[7] << 8) + buf[8];
return sectrue;
}
typedef struct {
uint8_t iface_num;
uint8_t packet_index;
uint8_t packet_pos;
uint8_t buf[USB_PACKET_SIZE];
} usb_write_state;
/* we don't use secbool/sectrue/secfalse here as it is a nanopb api */
static bool _usb_write(pb_ostream_t *stream, const pb_byte_t *buf,
size_t count) {
usb_write_state *state = (usb_write_state *)(stream->state);
size_t written = 0;
// while we have data left
while (written < count) {
size_t remaining = count - written;
// if all remaining data fit into our packet
if (state->packet_pos + remaining <= USB_PACKET_SIZE) {
// append data from buf to state->buf
memcpy(state->buf + state->packet_pos, buf + written, remaining);
// advance position
state->packet_pos += remaining;
// and return
return true;
} else {
// append data that fits
memcpy(state->buf + state->packet_pos, buf + written,
USB_PACKET_SIZE - state->packet_pos);
written += USB_PACKET_SIZE - state->packet_pos;
// send packet
int r = usb_webusb_write_blocking(state->iface_num, state->buf,
USB_PACKET_SIZE, USB_TIMEOUT);
ensure(sectrue * (r == USB_PACKET_SIZE), NULL);
// prepare new packet
state->packet_index++;
memzero(state->buf, USB_PACKET_SIZE);
state->buf[0] = '?';
state->packet_pos = MSG_HEADER2_LEN;
}
}
return true;
}
static void _usb_write_flush(usb_write_state *state) {
// if packet is not filled up completely
if (state->packet_pos < USB_PACKET_SIZE) {
// pad it with zeroes
memzero(state->buf + state->packet_pos,
USB_PACKET_SIZE - state->packet_pos);
}
// send packet
int r = usb_webusb_write_blocking(state->iface_num, state->buf,
USB_PACKET_SIZE, USB_TIMEOUT);
ensure(sectrue * (r == USB_PACKET_SIZE), NULL);
}
static secbool _send_msg(uint8_t iface_num, uint16_t msg_id,
const pb_msgdesc_t *fields, const void *msg) {
// determine message size by serializing it into a dummy stream
pb_ostream_t sizestream = {.callback = NULL,
.state = NULL,
.max_size = SIZE_MAX,
.bytes_written = 0,
.errmsg = NULL};
if (false == pb_encode(&sizestream, fields, msg)) {
return secfalse;
}
const uint32_t msg_size = sizestream.bytes_written;
usb_write_state state = {
.iface_num = iface_num,
.packet_index = 0,
.packet_pos = MSG_HEADER1_LEN,
.buf =
{
'?',
'#',
'#',
(msg_id >> 8) & 0xFF,
msg_id & 0xFF,
(msg_size >> 24) & 0xFF,
(msg_size >> 16) & 0xFF,
(msg_size >> 8) & 0xFF,
msg_size & 0xFF,
},
};
pb_ostream_t stream = {.callback = &_usb_write,
.state = &state,
.max_size = SIZE_MAX,
.bytes_written = 0,
.errmsg = NULL};
if (false == pb_encode(&stream, fields, msg)) {
return secfalse;
}
_usb_write_flush(&state);
return sectrue;
}
#define MSG_SEND_INIT(TYPE) TYPE msg_send = TYPE##_init_default
#define MSG_SEND_ASSIGN_REQUIRED_VALUE(FIELD, VALUE) \
{ msg_send.FIELD = VALUE; }
#define MSG_SEND_ASSIGN_VALUE(FIELD, VALUE) \
{ \
msg_send.has_##FIELD = true; \
msg_send.FIELD = VALUE; \
}
#define MSG_SEND_ASSIGN_STRING(FIELD, VALUE) \
{ \
msg_send.has_##FIELD = true; \
memzero(msg_send.FIELD, sizeof(msg_send.FIELD)); \
strncpy(msg_send.FIELD, VALUE, sizeof(msg_send.FIELD) - 1); \
}
#define MSG_SEND_ASSIGN_STRING_LEN(FIELD, VALUE, LEN) \
{ \
msg_send.has_##FIELD = true; \
memzero(msg_send.FIELD, sizeof(msg_send.FIELD)); \
strncpy(msg_send.FIELD, VALUE, MIN(LEN, sizeof(msg_send.FIELD) - 1)); \
}
#define MSG_SEND_ASSIGN_BYTES(FIELD, VALUE, LEN) \
{ \
msg_send.has_##FIELD = true; \
memzero(msg_send.FIELD.bytes, sizeof(msg_send.FIELD.bytes)); \
memcpy(msg_send.FIELD.bytes, VALUE, \
MIN(LEN, sizeof(msg_send.FIELD.bytes))); \
msg_send.FIELD.size = MIN(LEN, sizeof(msg_send.FIELD.bytes)); \
}
#define MSG_SEND(TYPE) \
_send_msg(iface_num, MessageType_MessageType_##TYPE, TYPE##_fields, &msg_send)
typedef struct {
uint8_t iface_num;
uint8_t packet_index;
uint8_t packet_pos;
uint8_t *buf;
} usb_read_state;
static void _usb_webusb_read_retry(uint8_t iface_num, uint8_t *buf) {
for (int retry = 0;; retry++) {
int r =
usb_webusb_read_blocking(iface_num, buf, USB_PACKET_SIZE, USB_TIMEOUT);
if (r != USB_PACKET_SIZE) { // reading failed
if (r == 0 && retry < 10) {
// only timeout => let's try again
} else {
// error
error_shutdown("Error reading", "from USB.", "Try different",
"USB cable.");
}
}
return; // success
}
}
/* we don't use secbool/sectrue/secfalse here as it is a nanopb api */
static bool _usb_read(pb_istream_t *stream, uint8_t *buf, size_t count) {
usb_read_state *state = (usb_read_state *)(stream->state);
size_t read = 0;
// while we have data left
while (read < count) {
size_t remaining = count - read;
// if all remaining data fit into our packet
if (state->packet_pos + remaining <= USB_PACKET_SIZE) {
// append data from buf to state->buf
memcpy(buf + read, state->buf + state->packet_pos, remaining);
// advance position
state->packet_pos += remaining;
// and return
return true;
} else {
// append data that fits
memcpy(buf + read, state->buf + state->packet_pos,
USB_PACKET_SIZE - state->packet_pos);
read += USB_PACKET_SIZE - state->packet_pos;
// read next packet (with retry)
_usb_webusb_read_retry(state->iface_num, state->buf);
// prepare next packet
state->packet_index++;
state->packet_pos = MSG_HEADER2_LEN;
}
}
return true;
}
static void _usb_read_flush(usb_read_state *state) { (void)state; }
static secbool _recv_msg(uint8_t iface_num, uint32_t msg_size, uint8_t *buf,
const pb_msgdesc_t *fields, void *msg) {
usb_read_state state = {.iface_num = iface_num,
.packet_index = 0,
.packet_pos = MSG_HEADER1_LEN,
.buf = buf};
pb_istream_t stream = {.callback = &_usb_read,
.state = &state,
.bytes_left = msg_size,
.errmsg = NULL};
if (false == pb_decode_noinit(&stream, fields, msg)) {
return secfalse;
}
_usb_read_flush(&state);
return sectrue;
}
#define MSG_RECV_INIT(TYPE) TYPE msg_recv = TYPE##_init_default
#define MSG_RECV_CALLBACK(FIELD, CALLBACK, ARGUMENT) \
{ \
msg_recv.FIELD.funcs.decode = &CALLBACK; \
msg_recv.FIELD.arg = (void *)ARGUMENT; \
}
#define MSG_RECV(TYPE) \
_recv_msg(iface_num, msg_size, buf, TYPE##_fields, &msg_recv)
void send_user_abort(uint8_t iface_num, const char *msg) {
MSG_SEND_INIT(Failure);
MSG_SEND_ASSIGN_VALUE(code, FailureType_Failure_ActionCancelled);
MSG_SEND_ASSIGN_STRING(message, msg);
MSG_SEND(Failure);
}
static void send_msg_features(uint8_t iface_num,
const vendor_header *const vhdr,
const image_header *const hdr) {
MSG_SEND_INIT(Features);
MSG_SEND_ASSIGN_STRING(vendor, "trezor.io");
MSG_SEND_ASSIGN_REQUIRED_VALUE(major_version, VERSION_MAJOR);
MSG_SEND_ASSIGN_REQUIRED_VALUE(minor_version, VERSION_MINOR);
MSG_SEND_ASSIGN_REQUIRED_VALUE(patch_version, VERSION_PATCH);
MSG_SEND_ASSIGN_VALUE(bootloader_mode, true);
MSG_SEND_ASSIGN_STRING(model, "T");
if (vhdr && hdr) {
MSG_SEND_ASSIGN_VALUE(firmware_present, true);
MSG_SEND_ASSIGN_VALUE(fw_major, (hdr->version & 0xFF));
MSG_SEND_ASSIGN_VALUE(fw_minor, ((hdr->version >> 8) & 0xFF));
MSG_SEND_ASSIGN_VALUE(fw_patch, ((hdr->version >> 16) & 0xFF));
MSG_SEND_ASSIGN_STRING_LEN(fw_vendor, vhdr->vstr, vhdr->vstr_len);
uint8_t hash[32];
vendor_header_hash(vhdr, hash);
MSG_SEND_ASSIGN_BYTES(fw_vendor_keys, hash, 32);
} else {
MSG_SEND_ASSIGN_VALUE(firmware_present, false);
}
MSG_SEND(Features);
}
void process_msg_Initialize(uint8_t iface_num, uint32_t msg_size, uint8_t *buf,
const vendor_header *const vhdr,
const image_header *const hdr) {
MSG_RECV_INIT(Initialize);
MSG_RECV(Initialize);
send_msg_features(iface_num, vhdr, hdr);
}
void process_msg_GetFeatures(uint8_t iface_num, uint32_t msg_size, uint8_t *buf,
const vendor_header *const vhdr,
const image_header *const hdr) {
MSG_RECV_INIT(GetFeatures);
MSG_RECV(GetFeatures);
send_msg_features(iface_num, vhdr, hdr);
}
void process_msg_Ping(uint8_t iface_num, uint32_t msg_size, uint8_t *buf) {
MSG_RECV_INIT(Ping);
MSG_RECV(Ping);
MSG_SEND_INIT(Success);
MSG_SEND_ASSIGN_STRING(message, msg_recv.message);
MSG_SEND(Success);
}
static uint32_t firmware_remaining, firmware_block, chunk_requested;
void process_msg_FirmwareErase(uint8_t iface_num, uint32_t msg_size,
uint8_t *buf) {
firmware_remaining = 0;
firmware_block = 0;
chunk_requested = 0;
MSG_RECV_INIT(FirmwareErase);
MSG_RECV(FirmwareErase);
firmware_remaining = msg_recv.has_length ? msg_recv.length : 0;
if ((firmware_remaining > 0) &&
((firmware_remaining % sizeof(uint32_t)) == 0) &&
(firmware_remaining <= (FIRMWARE_SECTORS_COUNT * IMAGE_CHUNK_SIZE))) {
// request new firmware
chunk_requested = (firmware_remaining > IMAGE_INIT_CHUNK_SIZE)
? IMAGE_INIT_CHUNK_SIZE
: firmware_remaining;
MSG_SEND_INIT(FirmwareRequest);
MSG_SEND_ASSIGN_VALUE(offset, 0);
MSG_SEND_ASSIGN_VALUE(length, chunk_requested);
MSG_SEND(FirmwareRequest);
} else {
// invalid firmware size
MSG_SEND_INIT(Failure);
MSG_SEND_ASSIGN_VALUE(code, FailureType_Failure_ProcessError);
MSG_SEND_ASSIGN_STRING(message, "Wrong firmware size");
MSG_SEND(Failure);
}
}
static uint32_t chunk_size = 0;
// SRAM is unused, so we can use it for chunk buffer
uint8_t *const chunk_buffer = (uint8_t *const)0x20000000;
/* we don't use secbool/sectrue/secfalse here as it is a nanopb api */
static bool _read_payload(pb_istream_t *stream, const pb_field_t *field,
void **arg) {
#define BUFSIZE 32768
uint32_t offset = (uint32_t)(*arg);
if (stream->bytes_left > IMAGE_CHUNK_SIZE) {
chunk_size = 0;
return false;
}
if (offset == 0) {
// clear chunk buffer
memset(chunk_buffer, 0xFF, IMAGE_CHUNK_SIZE);
}
uint32_t chunk_written = offset;
chunk_size = offset + stream->bytes_left;
while (stream->bytes_left) {
// update loader but skip first block
if (firmware_block > 0) {
ui_screen_install_progress_upload(
250 + 750 * (firmware_block * IMAGE_CHUNK_SIZE + chunk_written) /
(firmware_block * IMAGE_CHUNK_SIZE + firmware_remaining));
}
// read data
if (!pb_read(
stream, (pb_byte_t *)(chunk_buffer + chunk_written),
(stream->bytes_left > BUFSIZE) ? BUFSIZE : stream->bytes_left)) {
chunk_size = 0;
return false;
}
chunk_written += BUFSIZE;
}
return true;
}
secbool load_vendor_header_keys(const uint8_t *const data,
vendor_header *const vhdr);
static int version_compare(uint32_t vera, uint32_t verb) {
int a, b;
a = vera & 0xFF;
b = verb & 0xFF;
if (a != b) return a - b;
a = (vera >> 8) & 0xFF;
b = (verb >> 8) & 0xFF;
if (a != b) return a - b;
a = (vera >> 16) & 0xFF;
b = (verb >> 16) & 0xFF;
if (a != b) return a - b;
a = (vera >> 24) & 0xFF;
b = (verb >> 24) & 0xFF;
return a - b;
}
static void detect_installation(vendor_header *current_vhdr,
image_header *current_hdr,
const vendor_header *const new_vhdr,
const image_header *const new_hdr,
secbool *is_new, secbool *is_upgrade,
secbool *is_downgrade_wipe) {
*is_new = secfalse;
*is_upgrade = secfalse;
*is_downgrade_wipe = secfalse;
if (sectrue !=
load_vendor_header_keys((const uint8_t *)FIRMWARE_START, current_vhdr)) {
*is_new = sectrue;
return;
}
if (sectrue !=
load_image_header((const uint8_t *)FIRMWARE_START + current_vhdr->hdrlen,
FIRMWARE_IMAGE_MAGIC, FIRMWARE_IMAGE_MAXSIZE,
current_vhdr->vsig_m, current_vhdr->vsig_n,
current_vhdr->vpub, current_hdr)) {
*is_new = sectrue;
return;
}
uint8_t hash1[32], hash2[32];
vendor_header_hash(new_vhdr, hash1);
vendor_header_hash(current_vhdr, hash2);
if (0 != memcmp(hash1, hash2, 32)) {
return;
}
if (version_compare(new_hdr->version, current_hdr->fix_version) < 0) {
*is_downgrade_wipe = sectrue;
return;
}
*is_upgrade = sectrue;
}
static int firmware_upload_chunk_retry = FIRMWARE_UPLOAD_CHUNK_RETRY_COUNT;
static uint32_t headers_offset = 0;
static uint32_t read_offset = 0;
int process_msg_FirmwareUpload(uint8_t iface_num, uint32_t msg_size,
uint8_t *buf) {
MSG_RECV_INIT(FirmwareUpload);
MSG_RECV_CALLBACK(payload, _read_payload, read_offset);
const secbool r = MSG_RECV(FirmwareUpload);
if (sectrue != r || chunk_size != (chunk_requested + read_offset)) {
MSG_SEND_INIT(Failure);
MSG_SEND_ASSIGN_VALUE(code, FailureType_Failure_ProcessError);
MSG_SEND_ASSIGN_STRING(message, "Invalid chunk size");
MSG_SEND(Failure);
return -1;
}
static image_header hdr;
secbool is_upgrade = secfalse;
secbool is_downgrade_wipe = secfalse;
if (firmware_block == 0) {
if (headers_offset == 0) {
// first block and headers are not yet parsed
vendor_header vhdr;
if (sectrue != load_vendor_header_keys(chunk_buffer, &vhdr)) {
MSG_SEND_INIT(Failure);
MSG_SEND_ASSIGN_VALUE(code, FailureType_Failure_ProcessError);
MSG_SEND_ASSIGN_STRING(message, "Invalid vendor header");
MSG_SEND(Failure);
return -2;
}
if (sectrue != load_image_header(chunk_buffer + vhdr.hdrlen,
FIRMWARE_IMAGE_MAGIC,
FIRMWARE_IMAGE_MAXSIZE, vhdr.vsig_m,
vhdr.vsig_n, vhdr.vpub, &hdr)) {
MSG_SEND_INIT(Failure);
MSG_SEND_ASSIGN_VALUE(code, FailureType_Failure_ProcessError);
MSG_SEND_ASSIGN_STRING(message, "Invalid firmware header");
MSG_SEND(Failure);
return -3;
}
vendor_header current_vhdr;
image_header current_hdr;
secbool is_new = secfalse;
detect_installation(&current_vhdr, &current_hdr, &vhdr, &hdr, &is_new,
&is_upgrade, &is_downgrade_wipe);
// no user confirmations, go directly to upload
headers_offset = IMAGE_HEADER_SIZE + vhdr.hdrlen;
read_offset = IMAGE_INIT_CHUNK_SIZE;
// request the rest of the first chunk
MSG_SEND_INIT(FirmwareRequest);
chunk_requested = IMAGE_CHUNK_SIZE - read_offset;
MSG_SEND_ASSIGN_VALUE(offset, read_offset);
MSG_SEND_ASSIGN_VALUE(length, chunk_requested);
MSG_SEND(FirmwareRequest);
firmware_remaining -= read_offset;
return (int)firmware_remaining;
} else {
// first block with the headers parsed -> the first chunk is now complete
read_offset = 0;
ui_fadeout();
ui_screen_install_start();
ui_fadein();
ensure(flash_erase_sectors(FIRMWARE_SECTORS, FIRMWARE_SECTORS_COUNT,
ui_screen_install_progress_erase),
NULL);
}
}
// should not happen, but double-check
if (firmware_block >= FIRMWARE_SECTORS_COUNT) {
MSG_SEND_INIT(Failure);
MSG_SEND_ASSIGN_VALUE(code, FailureType_Failure_ProcessError);
MSG_SEND_ASSIGN_STRING(message, "Firmware too big");
MSG_SEND(Failure);
return -5;
}
if (sectrue != check_single_hash(hdr.hashes + firmware_block * 32,
chunk_buffer + headers_offset,
chunk_size - headers_offset)) {
if (firmware_upload_chunk_retry > 0) {
--firmware_upload_chunk_retry;
MSG_SEND_INIT(FirmwareRequest);
MSG_SEND_ASSIGN_VALUE(offset, firmware_block * IMAGE_CHUNK_SIZE);
MSG_SEND_ASSIGN_VALUE(length, chunk_requested);
MSG_SEND(FirmwareRequest);
return (int)firmware_remaining;
}
MSG_SEND_INIT(Failure);
MSG_SEND_ASSIGN_VALUE(code, FailureType_Failure_ProcessError);
MSG_SEND_ASSIGN_STRING(message, "Invalid chunk hash");
MSG_SEND(Failure);
return -6;
}
ensure(flash_unlock_write(), NULL);
const uint32_t *const src = (const uint32_t *const)chunk_buffer;
for (int i = 0; i < chunk_size / sizeof(uint32_t); i++) {
ensure(flash_write_word(FIRMWARE_SECTORS[firmware_block],
i * sizeof(uint32_t), src[i]),
NULL);
}
ensure(flash_lock_write(), NULL);
headers_offset = 0;
firmware_remaining -= chunk_requested;
firmware_block++;
firmware_upload_chunk_retry = FIRMWARE_UPLOAD_CHUNK_RETRY_COUNT;
if (firmware_remaining > 0) {
chunk_requested = (firmware_remaining > IMAGE_CHUNK_SIZE)
? IMAGE_CHUNK_SIZE
: firmware_remaining;
MSG_SEND_INIT(FirmwareRequest);
MSG_SEND_ASSIGN_VALUE(offset, firmware_block * IMAGE_CHUNK_SIZE);
MSG_SEND_ASSIGN_VALUE(length, chunk_requested);
MSG_SEND(FirmwareRequest);
} else {
MSG_SEND_INIT(Success);
MSG_SEND(Success);
}
return (int)firmware_remaining;
}
int process_msg_WipeDevice(uint8_t iface_num, uint32_t msg_size, uint8_t *buf) {
static const uint8_t sectors[] = {
FLASH_SECTOR_STORAGE_1,
FLASH_SECTOR_STORAGE_2,
// 3, // skip because of MPU protection
FLASH_SECTOR_FIRMWARE_START,
7,
8,
9,
10,
FLASH_SECTOR_FIRMWARE_END,
FLASH_SECTOR_UNUSED_START,
13,
14,
// FLASH_SECTOR_UNUSED_END, // skip because of MPU protection
FLASH_SECTOR_FIRMWARE_EXTRA_START,
18,
19,
20,
21,
22,
FLASH_SECTOR_FIRMWARE_EXTRA_END,
};
if (sectrue !=
flash_erase_sectors(sectors, sizeof(sectors), ui_screen_wipe_progress)) {
MSG_SEND_INIT(Failure);
MSG_SEND_ASSIGN_VALUE(code, FailureType_Failure_ProcessError);
MSG_SEND_ASSIGN_STRING(message, "Could not erase flash");
MSG_SEND(Failure);
return -1;
} else {
MSG_SEND_INIT(Success);
MSG_SEND(Success);
return 0;
}
}
void process_msg_unknown(uint8_t iface_num, uint32_t msg_size, uint8_t *buf) {
// consume remaining message
int remaining_chunks = 0;
if (msg_size > (USB_PACKET_SIZE - MSG_HEADER1_LEN)) {
// calculate how many blocks need to be read to drain the message (rounded
// up to not leave any behind)
remaining_chunks = (msg_size - (USB_PACKET_SIZE - MSG_HEADER1_LEN) +
((USB_PACKET_SIZE - MSG_HEADER2_LEN) - 1)) /
(USB_PACKET_SIZE - MSG_HEADER2_LEN);
}
for (int i = 0; i < remaining_chunks; i++) {
// read next packet (with retry)
_usb_webusb_read_retry(iface_num, buf);
}
MSG_SEND_INIT(Failure);
MSG_SEND_ASSIGN_VALUE(code, FailureType_Failure_UnexpectedMessage);
MSG_SEND_ASSIGN_STRING(message, "Unexpected message");
MSG_SEND(Failure);
}