def fetch_previous_mnemonics() -> Optional[List[List[str]]]:
mnemonics = []
if not storage_recovery.get_slip39_group_count():
return None
for i in range(storage_recovery.get_slip39_group_count()):
mnemonics.append(storage_recovery_shares.fetch_group(i))
if not any(p for p in mnemonics):
return None
return mnemonics
def fetch() -> List[str]:
mnemonics = []
if not recovery.get_slip39_group_count():
raise RuntimeError
for index in range(
0, slip39.MAX_SHARE_COUNT * recovery.get_slip39_group_count()):
m = get(index)
if m:
mnemonics.append(m)
return mnemonics
async def _request_share_next_screen(ctx: wire.GenericContext) -> 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")
def process_slip39(words: str) -> Tuple[Optional[bytes], slip39.Share]:
"""
Processes a single mnemonic share. Returns the encrypted master secret
(or None if more shares are needed) and the share's group index and member index.
"""
share = slip39.decode_mnemonic(words)
remaining = storage_recovery.fetch_slip39_remaining_shares()
# if this is the first share, parse and store metadata
if not remaining:
storage_recovery.set_slip39_group_count(share.group_count)
storage_recovery.set_slip39_iteration_exponent(share.iteration_exponent)
storage_recovery.set_slip39_identifier(share.identifier)
storage_recovery.set_slip39_remaining_shares(
share.threshold - 1, share.group_index
)
storage_recovery_shares.set(share.index, share.group_index, words)
# if share threshold and group threshold are 1
# we can calculate the secret right away
if share.threshold == 1 and share.group_threshold == 1:
identifier, iteration_exponent, secret, _ = slip39.combine_mnemonics(
[words]
)
return secret, share
else:
# we need more shares
return None, share
# These should be checked by UI before so it's a Runtime exception otherwise
if share.identifier != storage_recovery.get_slip39_identifier():
raise RuntimeError("Slip39: Share identifiers do not match")
if share.iteration_exponent != storage_recovery.get_slip39_iteration_exponent():
raise RuntimeError("Slip39: Share exponents do not match")
if storage_recovery_shares.get(share.index, share.group_index):
raise RuntimeError("Slip39: This mnemonic was already entered")
if share.group_count != storage_recovery.get_slip39_group_count():
raise RuntimeError("Slip39: Group count does not match")
remaining_for_share = (
storage_recovery.get_slip39_remaining_shares(share.group_index)
or share.threshold
)
storage_recovery.set_slip39_remaining_shares(
remaining_for_share - 1, share.group_index
)
remaining[share.group_index] = remaining_for_share - 1
storage_recovery_shares.set(share.index, share.group_index, words)
if remaining.count(0) < share.group_threshold:
# we need more shares
return None, share
if share.group_count > 1:
mnemonics = []
for i, r in enumerate(remaining):
# if we have multiple groups pass only the ones with threshold reached
if r == 0:
group = storage_recovery_shares.fetch_group(i)
mnemonics.extend(group)
else:
# in case of slip39 basic we only need the first and only group
mnemonics = storage_recovery_shares.fetch_group(0)
identifier, iteration_exponent, secret, _ = slip39.combine_mnemonics(mnemonics)
return secret, share