You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
trezor-firmware/core/src/apps/management/reset_device/__init__.py

324 lines
11 KiB

from typing import TYPE_CHECKING
import storage
import storage.device as storage_device
from trezor.crypto import slip39
from trezor.enums import BackupType
from trezor.wire import ActionCancelled, ProcessError
from . import layout
if __debug__:
import storage.debug
if TYPE_CHECKING:
from trezor.messages import ResetDevice, Success
BAK_T_BIP39 = BackupType.Bip39 # global_import_cache
BAK_T_SLIP39_BASIC = BackupType.Slip39_Basic # global_import_cache
BAK_T_SLIP39_ADVANCED = BackupType.Slip39_Advanced # global_import_cache
_DEFAULT_BACKUP_TYPE = BAK_T_BIP39
async def reset_device(msg: ResetDevice) -> Success:
from trezor import config
from trezor.crypto import bip39, random
from trezor.messages import EntropyAck, EntropyRequest, Success
from trezor.pin import render_empty_loader
from trezor.ui.layouts import confirm_reset_device, prompt_backup
from trezor.wire.context import call
from apps.common.request_pin import request_pin_confirm
backup_type = msg.backup_type # local_cache_attribute
# validate parameters and device state
_validate_reset_device(msg)
# make sure user knows they're setting up a new wallet
if backup_type in (BAK_T_SLIP39_BASIC, BAK_T_SLIP39_ADVANCED):
title = "Create wallet (Shamir)"
else:
title = "Create wallet"
await confirm_reset_device(title)
# Rendering empty loader so users do not feel a freezing screen
render_empty_loader("PROCESSING", "")
# wipe storage to make sure the device is in a clear state
storage.reset()
# request and set new PIN
if msg.pin_protection:
newpin = await request_pin_confirm()
if not config.change_pin("", newpin, None, None):
raise ProcessError("Failed to set PIN")
# generate and display internal entropy
int_entropy = random.bytes(32, True)
if __debug__:
storage.debug.reset_internal_entropy = int_entropy
if msg.display_random:
await layout.show_internal_entropy(int_entropy)
# request external entropy and compute the master secret
entropy_ack = await call(EntropyRequest(), EntropyAck)
ext_entropy = entropy_ack.entropy
# For SLIP-39 this is the Encrypted Master Secret
secret = _compute_secret_from_entropy(int_entropy, ext_entropy, msg.strength)
# Check backup type, perform type-specific handling
if backup_type == BAK_T_BIP39:
# in BIP-39 we store mnemonic string instead of the secret
secret = bip39.from_data(secret).encode()
elif backup_type in (BAK_T_SLIP39_BASIC, BAK_T_SLIP39_ADVANCED):
# generate and set SLIP39 parameters
storage_device.set_slip39_identifier(slip39.generate_random_identifier())
storage_device.set_slip39_iteration_exponent(slip39.DEFAULT_ITERATION_EXPONENT)
else:
# Unknown backup type.
raise RuntimeError
# If either of skip_backup or no_backup is specified, we are not doing backup now.
# Otherwise, we try to do it.
perform_backup = not msg.no_backup and not msg.skip_backup
# If doing backup, ask the user to confirm.
if perform_backup:
perform_backup = await prompt_backup()
# generate and display backup information for the master secret
if perform_backup:
await backup_seed(backup_type, secret)
# write settings and master secret into storage
if msg.label is not None:
storage_device.set_label(msg.label)
storage_device.set_passphrase_enabled(bool(msg.passphrase_protection))
storage_device.store_mnemonic_secret(
secret, # for SLIP-39, this is the EMS
backup_type,
needs_backup=not perform_backup,
no_backup=bool(msg.no_backup),
)
# if we backed up the wallet, show success message
if perform_backup:
await layout.show_backup_success()
return Success(message="Initialized")
async def _backup_mnemonic_or_share(
mnemonic: bytes,
backup_type: BackupType,
share_index: int | None = None,
shares_total: int | None = None,
group_index: int | None = None,
groups_total: int | None = None,
):
from storage.sd_seed_backup import BackupMedium
from trezor import utils
while True:
# let the user choose between Words/SDcard backup
backup_medium = BackupMedium.Words
if utils.USE_SD_CARD:
backup_medium = await layout.choose_backup_medium(share_index, group_index)
# proceed with backup
if backup_medium == BackupMedium.Words:
# show words
await layout.show_and_confirm_mnemonic(
mnemonic.decode(),
share_index=share_index,
shares_total=shares_total,
group_index=group_index,
groups_total=groups_total,
)
return
else:
# try to store seed on SD card
try:
await sdcard_backup_seed(mnemonic, backup_type)
return
except ActionCancelled:
# 1) Not a Trezor card.
# 2) Backup present on the card.
# TODO show guidance: Pick different card/choose words
pass
except Exception:
# generic exception, let the user choose again
pass
async def sdcard_backup_seed(mnemonic_secret: bytes, backup_type: BackupType) -> None:
from storage.sd_seed_backup import is_backup_present_on_sdcard, store_seed_on_sdcard
from trezor.ui.layouts import confirm_action, show_success
from trezor.ui.layouts.sdcard_eject import make_user_eject_sdcard
from apps.common.sdcard import ensure_sdcard, is_trz_card
await ensure_sdcard(ensure_filesystem=False)
if not is_trz_card():
await confirm_action(
"confirm_not_trezor_card",
"Not Trezor card",
action="This is not Trezor Card! Still continue?",
verb="Continue",
)
if is_backup_present_on_sdcard():
await confirm_action(
"confirm_sdcard_backup_exists",
"Backup present",
action="There is already a Trezor backup on this card!",
description="Replace the backup?",
verb="Replace",
verb_cancel="Abort",
hold=True,
hold_danger=True,
reverse=True,
)
await ensure_sdcard(ensure_filesystem=True, for_sd_backup=True)
store_seed_on_sdcard(mnemonic_secret, backup_type)
await show_success("success_sdcard_backup", "Backup on SD card successful!")
await make_user_eject_sdcard()
async def _backup_bip39(mnemonic_secret: bytes):
await layout.show_backup_warning()
await _backup_mnemonic_or_share(mnemonic_secret, BAK_T_BIP39)
async def _backup_slip39_basic(encrypted_master_secret: bytes) -> None:
# get number of shares
await layout.slip39_show_checklist(0, BAK_T_SLIP39_BASIC)
shares_count = await layout.slip39_prompt_number_of_shares()
# get threshold
await layout.slip39_show_checklist(1, BAK_T_SLIP39_BASIC)
threshold = await layout.slip39_prompt_threshold(shares_count)
identifier = storage_device.get_slip39_identifier()
iteration_exponent = storage_device.get_slip39_iteration_exponent()
if identifier is None or iteration_exponent is None:
raise ValueError
# generate the mnemonics
mnemonics = slip39.split_ems(
1, # Single Group threshold
[(threshold, shares_count)], # Single Group threshold/count
identifier,
iteration_exponent,
encrypted_master_secret,
)[0]
# backup individual shares
await layout.slip39_show_checklist(2, BAK_T_SLIP39_BASIC)
await layout.show_backup_warning(True)
for share_index, share in enumerate(mnemonics):
await _backup_mnemonic_or_share(
share.encode(),
BAK_T_SLIP39_BASIC,
share_index,
len(mnemonics),
)
async def _backup_slip39_advanced(encrypted_master_secret: bytes) -> None:
# get number of groups
await layout.slip39_show_checklist(0, BAK_T_SLIP39_ADVANCED)
groups_count = await layout.slip39_advanced_prompt_number_of_groups()
# get group threshold
await layout.slip39_show_checklist(1, BAK_T_SLIP39_ADVANCED)
group_threshold = await layout.slip39_advanced_prompt_group_threshold(groups_count)
# get shares and thresholds
await layout.slip39_show_checklist(2, BAK_T_SLIP39_ADVANCED)
groups = []
for i in range(groups_count):
share_count = await layout.slip39_prompt_number_of_shares(i)
share_threshold = await layout.slip39_prompt_threshold(share_count, i)
groups.append((share_threshold, share_count))
identifier = storage_device.get_slip39_identifier()
iteration_exponent = storage_device.get_slip39_iteration_exponent()
if identifier is None or iteration_exponent is None:
raise ValueError
# generate the mnemonics
mnemonics = slip39.split_ems(
group_threshold,
groups,
identifier,
iteration_exponent,
encrypted_master_secret,
)
# backup individual shares
await layout.show_backup_warning(True)
for group_index, group in enumerate(mnemonics):
for share_index, share in enumerate(group):
await _backup_mnemonic_or_share(
share.encode(),
BAK_T_SLIP39_ADVANCED,
share_index,
len(group),
group_index,
len(mnemonics),
)
def _validate_reset_device(msg: ResetDevice) -> None:
from trezor.wire import UnexpectedMessage
from .. import backup_types
backup_type = msg.backup_type or _DEFAULT_BACKUP_TYPE
if backup_type not in (
BAK_T_BIP39,
BAK_T_SLIP39_BASIC,
BAK_T_SLIP39_ADVANCED,
):
raise ProcessError("Backup type not implemented.")
if backup_types.is_slip39_backup_type(backup_type):
if msg.strength not in (128, 256):
raise ProcessError("Invalid strength (has to be 128 or 256 bits)")
else: # BIP-39
if msg.strength not in (128, 192, 256):
raise ProcessError("Invalid strength (has to be 128, 192 or 256 bits)")
if msg.display_random and (msg.skip_backup or msg.no_backup):
raise ProcessError("Can't show internal entropy when backup is skipped")
if storage_device.is_initialized():
raise UnexpectedMessage("Already initialized")
def _compute_secret_from_entropy(
int_entropy: bytes, ext_entropy: bytes, strength_in_bytes: int
) -> bytes:
from trezor.crypto import hashlib
# combine internal and external entropy
ehash = hashlib.sha256()
ehash.update(int_entropy)
ehash.update(ext_entropy)
entropy = ehash.digest()
# take a required number of bytes
strength = strength_in_bytes // 8
secret = entropy[:strength]
return secret
async def backup_seed(backup_type: BackupType, mnemonic_secret: bytes) -> None:
if backup_type == BAK_T_SLIP39_BASIC:
await _backup_slip39_basic(mnemonic_secret)
elif backup_type == BAK_T_SLIP39_ADVANCED:
await _backup_slip39_advanced(mnemonic_secret)
else:
await _backup_bip39(mnemonic_secret)