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core/recovery: refactor to exceptions

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This commit is contained in:
Tomas Susanka 2019-12-27 19:02:30 +00:00
parent f4e11a9176
commit 7f730cb6f9
3 changed files with 56 additions and 50 deletions
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22
core/src/apps/management/recovery_device/layout.py
View File

@ -72,18 +72,20 @@ async def request_mnemonic(
else:
word = await ctx.wait(keyboard)
validity = word_validity.check(i, word, backup_type, words)
if validity != word_validity.OK:
if validity == word_validity.NOK_ALREADY_ADDED:
await show_share_already_added(ctx)
elif validity == word_validity.NOK_IDENTIFIER_MISMATCH:
await show_identifier_mismatch(ctx)
elif validity == word_validity.NOK_THRESHOLD_REACHED:
await show_group_threshold_reached(ctx)
return None
words.append(word)
try:
word_validity.check(backup_type, words)
except word_validity.AlreadyAdded:
await show_share_already_added(ctx)
return None
except word_validity.IdentifierMismatch:
await show_identifier_mismatch(ctx)
return None
except word_validity.ThresholdReached:
await show_group_threshold_reached(ctx)
return None
return " ".join(words)

60
core/src/apps/management/recovery_device/word_validity.py
View File

@ -1,5 +1,3 @@
from micropython import const
import storage.recovery
from trezor.messages import BackupType
@ -9,21 +7,32 @@ if False:
from typing import List, Optional
from trezor.messages.ResetDevice import EnumTypeBackupType
OK = const(0)
NOK_IDENTIFIER_MISMATCH = const(1)
NOK_ALREADY_ADDED = const(2)
NOK_THRESHOLD_REACHED = const(3)
class WordValidityResult(BaseException):
pass
class IdentifierMismatch(WordValidityResult):
pass
class AlreadyAdded(WordValidityResult):
pass
class ThresholdReached(WordValidityResult):
pass
def check(
backup_type: Optional[EnumTypeBackupType], partial_mnemonic: List[str]
) -> int:
) -> None:
# we can't perform any checks if the backup type was not yet decided
if backup_type is None:
return OK
return
# there are no "on-the-fly" checks for BIP-39
if backup_type is BackupType.Bip39:
return OK
return
previous_mnemonics = recover.fetch_previous_mnemonics()
if previous_mnemonics is None:
@ -31,18 +40,17 @@ def check(
raise RuntimeError
if backup_type == BackupType.Slip39_Basic:
return check_slip39_basic(partial_mnemonic, previous_mnemonics)
if backup_type == BackupType.Slip39_Advanced:
return check_slip39_advanced(partial_mnemonic, previous_mnemonics)
# there are no other backup types
raise RuntimeError
check_slip39_basic(partial_mnemonic, previous_mnemonics)
elif backup_type == BackupType.Slip39_Advanced:
check_slip39_advanced(partial_mnemonic, previous_mnemonics)
else:
# there are no other backup types
raise RuntimeError
def check_slip39_basic(
partial_mnemonic: List[str], previous_mnemonics: List[List[str]]
) -> int:
) -> None:
# check if first 3 words of mnemonic match
# we can check against the first one, others were checked already
current_index = len(partial_mnemonic) - 1
@ -50,26 +58,25 @@ def check_slip39_basic(
if current_index < 3:
share_list = previous_mnemonics[0][0].split(" ")
if share_list[current_index] != current_word:
return NOK_IDENTIFIER_MISMATCH
raise IdentifierMismatch
elif current_index == 3:
for share in previous_mnemonics[0]:
share_list = share.split(" ")
# check if the fourth word is different from previous shares
if share_list[current_index] == current_word:
return NOK_ALREADY_ADDED
return OK
raise AlreadyAdded
def check_slip39_advanced(
partial_mnemonic: List[str], previous_mnemonics: List[List[str]]
) -> int:
) -> None:
current_index = len(partial_mnemonic) - 1
current_word = partial_mnemonic[-1]
if current_index < 2:
share_list = next(s for s in previous_mnemonics if s)[0].split(" ")
if share_list[current_index] != current_word:
return NOK_IDENTIFIER_MISMATCH
raise IdentifierMismatch
# check if we reached threshold in group
elif current_index == 2:
for i, group in enumerate(previous_mnemonics):
@ -79,7 +86,8 @@ def check_slip39_advanced(
# if backup_type is not None, some share was already entered -> remaining needs to be set
assert remaining_shares is not None
if remaining_shares[i] == 0:
return NOK_THRESHOLD_REACHED
raise ThresholdReached
# check if share was already added for group
elif current_index == 3:
# we use the 3rd word from previously entered shares to find the group id
@ -94,6 +102,4 @@ def check_slip39_advanced(
group = previous_mnemonics[group_index]
for share in group:
if current_word == share.split(" ")[current_index]:
return NOK_ALREADY_ADDED
return OK
raise AlreadyAdded

24
core/tests/test_apps.management.recovery_device.py
View File

@ -5,7 +5,7 @@ import storage
import storage.recovery
from apps.management.recovery_device.recover import process_slip39
from trezor.messages import BackupType
from apps.management.recovery_device.word_validity import check, OK, NOK_IDENTIFIER_MISMATCH, NOK_ALREADY_ADDED, NOK_THRESHOLD_REACHED
from apps.management.recovery_device.word_validity import check, IdentifierMismatch, AlreadyAdded, ThresholdReached
MNEMONIC_SLIP39_BASIC_20_3of6 = [
"extra extend academic bishop cricket bundle tofu goat apart victim enlarge program behavior permit course armed jerky faint language modern",
@ -151,12 +151,10 @@ class TestSlip39(unittest.TestCase):
check(BackupType.Slip39_Advanced, ["ocean"])
# if backup type is not set we can not do any checks
result = check(None, ["ocean"])
self.assertIs(result, OK)
self.assertIsNone(check(None, ["ocean"]))
# BIP-39 has no "on-the-fly" checks
result = check(BackupType.Bip39, ["ocean"])
self.assertIs(result, OK)
self.assertIsNone(check(BackupType.Bip39, ["ocean"]))
# let's store two shares in the storage
secret, share = process_slip39("trash smug adjust ambition criminal prisoner security math cover pecan response pharmacy center criminal salary elbow bracelet lunar briefing dragon")
@ -165,16 +163,16 @@ class TestSlip39(unittest.TestCase):
self.assertIsNone(secret)
# different identifier
result = check(BackupType.Slip39_Advanced, ["slush"])
self.assertIs(result, NOK_IDENTIFIER_MISMATCH)
with self.assertRaises(IdentifierMismatch):
check(BackupType.Slip39_Advanced, ["slush"])
# same first word but still a different identifier
result = check(BackupType.Slip39_Advanced, ["trash", "slush"])
self.assertIs(result, NOK_IDENTIFIER_MISMATCH)
with self.assertRaises(IdentifierMismatch):
check(BackupType.Slip39_Advanced, ["trash", "slush"])
# same mnemonic found out using the index
result = check(BackupType.Slip39_Advanced, ["trash", "smug", "adjust", "ambition"])
self.assertIs(result, NOK_ALREADY_ADDED)
with self.assertRaises(AlreadyAdded):
check(BackupType.Slip39_Advanced, ["trash", "smug", "adjust", "ambition"])
# Let's store two more. The group is 4/6 so this group is now complete.
secret, share = process_slip39("trash smug adjust arena beard quick language program true hush amount round geology should training practice language diet order ruin")
@ -183,8 +181,8 @@ class TestSlip39(unittest.TestCase):
self.assertIsNone(secret)
# If trying to add another one from this group we get a warning.
result = check(BackupType.Slip39_Advanced, ["trash", "smug", "adjust"])
self.assertIs(result, NOK_THRESHOLD_REACHED)
with self.assertRaises(ThresholdReached):
check(BackupType.Slip39_Advanced, ["trash", "smug", "adjust"])
if __name__ == "__main__":