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lnbase: add RevocationStore test, remove unnecessary lnd helper functions

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This commit is contained in:
Janus
2018-05-11 15:43:47 +02:00
committed by ThomasV
parent cf82150aab
commit 3a20c8ce00
2 changed files with 22 additions and 74 deletions
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47
lib/lnbase.py
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@@ -320,30 +320,18 @@ def derive_blinded_pubkey(basepoint, per_commitment_point):
return point_to_ser(k1 + k2)
def shachain_derive(element, toIndex):
""" compact per-commitment secret storage, taken from lnd """
fromIndex = element.index
positions = derive_bit_transformations(fromIndex, toIndex)
buf = bytearray(element.secret)
for position in positions:
byteNumber = position // 8
bitNumber = position % 8
buf[byteNumber] ^= 1 << bitNumber
h = bitcoin.sha256(buf)
buf = bytearray(h)
return ShachainElement(index=toIndex, secret=bytes(buf))
return ShachainElement(get_per_commitment_secret_from_seed(element.secret, toIndex, count_trailing_zeros(element.index)), toIndex)
def get_per_commitment_secret_from_seed(seed: bytes, i: int, bits: int = 47) -> bytes:
def get_per_commitment_secret_from_seed(seed: bytes, i: int, bits: int = 48) -> bytes:
"""Generate per commitment secret."""
per_commitment_secret = bytearray(seed)
for bitindex in range(bits, -1, -1):
for bitindex in range(bits - 1, -1, -1):
mask = 1 << bitindex
if i & mask:
per_commitment_secret[bitindex // 8] ^= 1 << (bitindex % 8)
per_commitment_secret = bytearray(bitcoin.sha256(per_commitment_secret))
bajts = bytes(per_commitment_secret)
assert shachain_derive(ShachainElement(index=0, secret=seed), i).secret == bajts
return bajts
@@ -1569,44 +1557,21 @@ def count_trailing_zeros(index):
return 48
ShachainElement = namedtuple("ShachainElement", ["secret", "index"])
ShachainElement.__str__ = lambda self: "ShachainElement(" + bh2u(self.secret) + "," + str(self.index) + ")"
class RevocationStore:
""" taken from lnd """
def __init__(self):
self.buckets = {}
self.buckets = [None] * 48
self.index = 2**48 - 1
def set_index(self, index):
self.index = index
def add_next_entry(self, hsh):
new_element = ShachainElement(index=self.index, secret=hsh)
bucket = count_trailing_zeros(self.index)
for i in range(0, bucket):
if i not in self.buckets: return
this_bucket = self.buckets[i]
e = shachain_derive(new_element, this_bucket.index)
if e != this_bucket:
return "hash is not derivable: {} {} {}".format(bh2u(e.secret), bh2u(this_bucket.secret), this_bucket.index)
raise Exception("hash is not derivable: {} {} {}".format(bh2u(e.secret), bh2u(this_bucket.secret), this_bucket.index))
self.buckets[bucket] = new_element
self.index -= 1
return
def get_prefix(index, position):
""" taken from lnd """
mask = (1<<64)-1 - ((1<<position)-1)
return index & mask
def derive_bit_transformations(fromm, to):
""" taken from lnd """
positions = []
if fromm == to: return positions
zeros = count_trailing_zeros(fromm)
if fromm > (1<<64)-1: raise Exception("fromm too big")
if fromm != get_prefix(to, zeros):
raise Exception("prefixes are different, indexes are not derivable")
for position in range(zeros, -1, -1):
if to >> position & 1 == 1:
positions.append(position)
return positions