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trezor-firmware/core/src/apps/management/recovery_device/homescreen.py

264 lines
9.1 KiB

from trezor import loop, utils, wire
from trezor.crypto.hashlib import sha256
from trezor.crypto.slip39 import MAX_SHARE_COUNT, Share
from trezor.errors import MnemonicError
from trezor.messages import BackupType
from trezor.messages.Success import Success
from . import recover
from apps.common import mnemonic, storage
from apps.common.layout import show_success
from apps.management import backup_types
from apps.management.recovery_device import layout
if False:
from typing import Optional, Tuple
from trezor.messages.ResetDevice import EnumTypeBackupType
async def recovery_homescreen() -> None:
# recovery process does not communicate on the wire
ctx = wire.DummyContext()
try:
await recovery_process(ctx)
finally:
# clear the loop state, so loop.run will exit
loop.clear()
# clear the registered wire handlers to avoid conflicts
wire.clear()
async def recovery_process(ctx: wire.Context) -> Success:
try:
result = await _continue_recovery_process(ctx)
except recover.RecoveryAborted:
dry_run = storage.recovery.is_dry_run()
if dry_run:
storage.recovery.end_progress()
else:
storage.wipe()
raise wire.ActionCancelled("Cancelled")
return result
async def _continue_recovery_process(ctx: wire.Context) -> Success:
# gather the current recovery state from storage
word_count = storage.recovery.get_word_count()
dry_run = storage.recovery.is_dry_run()
backup_type = storage.recovery.get_backup_type()
if not word_count: # the first run, prompt word count from the user
word_count = await _request_and_store_word_count(ctx, dry_run)
is_slip39 = backup_types.is_slip39_word_count(word_count)
await _request_share_first_screen(ctx, word_count, is_slip39)
secret = None
while secret is None:
# ask for mnemonic words one by one
words = await layout.request_mnemonic(ctx, word_count, backup_type)
# if they were invalid or some checks failed we continue and request them again
if not words:
continue
try:
secret, backup_type = await _process_words(
ctx, words, is_slip39, backup_type
)
except MnemonicError:
await layout.show_invalid_mnemonic(ctx, is_slip39)
# If the backup type is not stored, we have processed zero mnemonics.
# In that case we prompt the word count again to give the user an
# opportunity to change the word count if they've made a mistake.
first_mnemonic = storage.recovery.get_backup_type() is None
if first_mnemonic:
word_count = await _request_and_store_word_count(ctx, dry_run)
is_slip39 = backup_types.is_slip39_word_count(word_count)
backup_type = None
continue
if dry_run:
result = await _finish_recovery_dry_run(ctx, secret)
else:
result = await _finish_recovery(ctx, secret)
return result
async def _finish_recovery_dry_run(ctx: wire.Context, secret: bytes) -> Success:
backup_type = storage.recovery.get_backup_type()
if backup_type is None:
raise RuntimeError
digest_input = sha256(secret).digest()
stored = mnemonic.get_secret()
digest_stored = sha256(stored).digest()
result = utils.consteq(digest_stored, digest_input)
is_slip39 = backup_types.is_slip39_backup_type(backup_type)
# Check that the identifier and iteration exponent match as well
if is_slip39:
result &= (
storage.device.get_slip39_identifier()
== storage.recovery.get_slip39_identifier()
)
result &= (
storage.device.get_slip39_iteration_exponent()
== storage.recovery.get_slip39_iteration_exponent()
)
await layout.show_dry_run_result(ctx, result, is_slip39)
storage.recovery.end_progress()
if result:
return Success("The seed is valid and matches the one in the device")
else:
raise wire.ProcessError("The seed does not match the one in the device")
async def _finish_recovery(ctx: wire.Context, secret: bytes) -> Success:
backup_type = storage.recovery.get_backup_type()
if backup_type is None:
raise RuntimeError
storage.device.store_mnemonic_secret(
secret, backup_type, needs_backup=False, no_backup=False
)
if backup_type in (BackupType.Slip39_Basic, BackupType.Slip39_Advanced):
identifier = storage.recovery.get_slip39_identifier()
exponent = storage.recovery.get_slip39_iteration_exponent()
if identifier is None or exponent is None:
# Identifier and exponent need to be stored in storage at this point
raise RuntimeError
storage.device.set_slip39_identifier(identifier)
storage.device.set_slip39_iteration_exponent(exponent)
await show_success(ctx, ("You have successfully", "recovered your wallet."))
storage.recovery.end_progress()
return Success(message="Device recovered")
async def _request_and_store_word_count(ctx: wire.Context, dry_run: bool) -> int:
homepage = layout.RecoveryHomescreen("Select number of words")
await layout.homescreen_dialog(ctx, homepage, "Select")
# ask for the number of words
word_count = await layout.request_word_count(ctx, dry_run)
# save them into storage
storage.recovery.set_word_count(word_count)
return word_count
async def _process_words(
ctx: wire.Context,
words: str,
is_slip39: bool,
backup_type: Optional[EnumTypeBackupType],
) -> Tuple[Optional[bytes], EnumTypeBackupType]:
share = None
if not is_slip39: # BIP-39
secret = recover.process_bip39(words)
else:
secret, share = recover.process_slip39(words)
if backup_type is None:
# we have to decide what backup type this is and store it
backup_type = _store_backup_type(is_slip39, share)
if secret is None:
if share.group_count and share.group_count > 1:
await layout.show_group_share_success(ctx, share.index, share.group_index)
await _request_share_next_screen(ctx)
return secret, backup_type
def _store_backup_type(is_slip39: bool, share: Share = None) -> EnumTypeBackupType:
if not is_slip39: # BIP-39
backup_type = BackupType.Bip39
elif not share or share.group_count < 1: # invalid parameters
raise RuntimeError
elif share.group_count == 1:
backup_type = BackupType.Slip39_Basic
else:
backup_type = BackupType.Slip39_Advanced
storage.recovery.set_backup_type(backup_type)
return backup_type
async def _request_share_first_screen(
ctx: wire.Context, word_count: int, is_slip39: bool
) -> None:
if is_slip39:
remaining = storage.recovery.fetch_slip39_remaining_shares()
if remaining:
await _request_share_next_screen(ctx)
else:
content = layout.RecoveryHomescreen(
"Enter any share", "(%d words)" % word_count
)
await layout.homescreen_dialog(ctx, content, "Enter share")
else: # BIP-39
content = layout.RecoveryHomescreen(
"Enter recovery seed", "(%d words)" % word_count
)
await layout.homescreen_dialog(ctx, content, "Enter seed")
async def _request_share_next_screen(ctx: wire.Context) -> None:
remaining = storage.recovery.fetch_slip39_remaining_shares()
group_count = storage.recovery.get_slip39_group_count()
if not remaining:
# 'remaining' should be stored at this point
raise RuntimeError
if group_count > 1:
content = layout.RecoveryHomescreen("More shares needed")
await layout.homescreen_dialog(
ctx, content, "Enter", _show_remaining_groups_and_shares
)
else:
if remaining[0] == 1:
text = "1 more share"
else:
text = "%d more shares" % remaining[0]
content = layout.RecoveryHomescreen(text, "needed to enter")
await layout.homescreen_dialog(ctx, content, "Enter share")
async def _show_remaining_groups_and_shares(ctx: wire.Context) -> None:
"""
Show info dialog for Slip39 Advanced - what shares are to be entered.
"""
shares_remaining = storage.recovery.fetch_slip39_remaining_shares()
identifiers = []
first_entered_index = -1
for i in range(len(shares_remaining)):
if shares_remaining[i] < MAX_SHARE_COUNT:
first_entered_index = i
for i, r in enumerate(shares_remaining):
if 0 < r < MAX_SHARE_COUNT:
identifier = storage.recovery_shares.fetch_group(i)[0].split(" ")[0:3]
identifiers.append([r, identifier])
elif r == MAX_SHARE_COUNT:
identifier = storage.recovery_shares.fetch_group(first_entered_index)[
0
].split(" ")[0:2]
try:
# we only add the group (two words) identifier once
identifiers.index([r, identifier])
except ValueError:
identifiers.append([r, identifier])
return await layout.show_remaining_shares(ctx, identifiers, shares_remaining)