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trezor-firmware/core/src/apps/management/reset_device/__init__.py

251 lines
8.7 KiB

from typing import TYPE_CHECKING, Sequence
import storage
import storage.device as storage_device
from trezor import TR
from trezor.crypto import slip39
from trezor.enums import BackupType
from trezor.ui.layouts import confirm_action
from trezor.wire import 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 TR, 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 = TR.reset__title_create_wallet_shamir
else:
title = TR.reset__title_create_wallet
await confirm_reset_device(title)
# Rendering empty loader so users do not feel a freezing screen
render_empty_loader(config.StorageMessage.PROCESSING_MSG)
# 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_slip39_basic(encrypted_master_secret: bytes) -> None:
group_threshold = 1
# get number of shares
await layout.slip39_show_checklist(0, BAK_T_SLIP39_BASIC)
share_count = await layout.slip39_prompt_number_of_shares()
# get threshold
await layout.slip39_show_checklist(1, BAK_T_SLIP39_BASIC)
share_threshold = await layout.slip39_prompt_threshold(share_count)
mnemonics = _get_slip39_mnemonics(
encrypted_master_secret, group_threshold, ((share_threshold, share_count),)
)
# show and confirm individual shares
await layout.slip39_show_checklist(2, BAK_T_SLIP39_BASIC)
await layout.slip39_basic_show_and_confirm_shares(mnemonics[0])
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))
mnemonics = _get_slip39_mnemonics(encrypted_master_secret, group_threshold, groups)
# show and confirm individual shares
await layout.slip39_advanced_show_and_confirm_shares(mnemonics)
async def backup_slip39_custom(
encrypted_master_secret: bytes,
group_threshold: int,
groups: Sequence[tuple[int, int]],
) -> None:
mnemonics = _get_slip39_mnemonics(encrypted_master_secret, group_threshold, groups)
# show and confirm individual shares
if len(groups) == 1 and groups[0][0] == 1 and groups[0][1] == 1:
# for a single 1-of-1 group, we use the same layouts as for BIP39
await layout.show_and_confirm_mnemonic(mnemonics[0][0])
else:
await confirm_action(
"warning_shamir_backup",
TR.reset__title_shamir_backup,
description=TR.reset__create_x_of_y_shamir_backup_template.format(
groups[0][0], groups[0][1]
),
verb=TR.buttons__continue,
)
if len(groups) == 1:
await layout.slip39_basic_show_and_confirm_shares(mnemonics[0])
else:
await layout.slip39_advanced_show_and_confirm_shares(mnemonics)
def _get_slip39_mnemonics(
encrypted_master_secret: bytes,
group_threshold: int,
groups: Sequence[tuple[int, int]],
):
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
return slip39.split_ems(
group_threshold,
groups,
identifier,
iteration_exponent,
encrypted_master_secret,
)
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 layout.show_and_confirm_mnemonic(mnemonic_secret.decode())