def verify_bp(bp_proof, amounts, masks):
"""Verifies Bulletproof"""
from apps.monero.xmr import bulletproof as bp
if amounts:
bp_proof.V = []
for i in range(len(amounts)):
C = crypto.gen_commitment(masks[i], amounts[i])
crypto.scalarmult_into(C, C, crypto.sc_inv_eight())
bp_proof.V.append(crypto.encodepoint(C))
bpi = bp.BulletProofBuilder()
res = bpi.verify(bp_proof)
gc.collect()
return res
def _generate_clsag(
message: bytes,
P: List[bytes],
p: Sc25519,
C_nonzero: List[bytes],
z: Sc25519,
Cout: Ge25519,
index: int,
mg_buff: List[bytes],
) -> List[bytes]:
sI = crypto.new_point() # sig.I
sD = crypto.new_point() # sig.D
sc1 = crypto.new_scalar() # sig.c1
a = crypto.random_scalar()
H = crypto.new_point()
D = crypto.new_point()
Cout_bf = crypto.encodepoint(Cout)
tmp_sc = crypto.new_scalar()
tmp = crypto.new_point()
tmp_bf = bytearray(32)
crypto.hash_to_point_into(H, P[index])
crypto.scalarmult_into(sI, H, p) # I = p*H
crypto.scalarmult_into(D, H, z) # D = z*H
crypto.sc_mul_into(tmp_sc, z, crypto.sc_inv_eight()) # 1/8*z
crypto.scalarmult_into(sD, H, tmp_sc) # sig.D = 1/8*z*H
sD = crypto.encodepoint(sD)
hsh_P = crypto.get_keccak() # domain, I, D, P, C, C_offset
hsh_C = crypto.get_keccak() # domain, I, D, P, C, C_offset
hsh_P.update(_HASH_KEY_CLSAG_AGG_0)
hsh_C.update(_HASH_KEY_CLSAG_AGG_1)
def hsh_PC(x):
nonlocal hsh_P, hsh_C
hsh_P.update(x)
hsh_C.update(x)
for x in P:
hsh_PC(x)
for x in C_nonzero:
hsh_PC(x)
hsh_PC(crypto.encodepoint_into(tmp_bf, sI))
hsh_PC(sD)
hsh_PC(Cout_bf)
mu_P = crypto.decodeint(hsh_P.digest())
mu_C = crypto.decodeint(hsh_C.digest())
del (hsh_PC, hsh_P, hsh_C)
c_to_hash = crypto.get_keccak() # domain, P, C, C_offset, message, aG, aH
c_to_hash.update(_HASH_KEY_CLSAG_ROUND)
for i in range(len(P)):
c_to_hash.update(P[i])
for i in range(len(P)):
c_to_hash.update(C_nonzero[i])
c_to_hash.update(Cout_bf)
c_to_hash.update(message)
chasher = c_to_hash.copy()
crypto.scalarmult_base_into(tmp, a)
chasher.update(crypto.encodepoint_into(tmp_bf, tmp)) # aG
crypto.scalarmult_into(tmp, H, a)
chasher.update(crypto.encodepoint_into(tmp_bf, tmp)) # aH
c = crypto.decodeint(chasher.digest())
del (chasher, H)
L = crypto.new_point()
R = crypto.new_point()
c_p = crypto.new_scalar()
c_c = crypto.new_scalar()
i = (index + 1) % len(P)
if i == 0:
crypto.sc_copy(sc1, c)
mg_buff.append(int_serialize.dump_uvarint_b(len(P)))
for _ in range(len(P)):
mg_buff.append(bytearray(32))
while i != index:
crypto.random_scalar(tmp_sc)
crypto.encodeint_into(mg_buff[i + 1], tmp_sc)
crypto.sc_mul_into(c_p, mu_P, c)
crypto.sc_mul_into(c_c, mu_C, c)
# L = tmp_sc * G + c_P * P[i] + c_c * C[i]
crypto.add_keys2_into(L, tmp_sc, c_p,
crypto.decodepoint_into(tmp, P[i]))
crypto.decodepoint_into(tmp, C_nonzero[i]) # C = C_nonzero - Cout
crypto.point_sub_into(tmp, tmp, Cout)
crypto.scalarmult_into(tmp, tmp, c_c)
crypto.point_add_into(L, L, tmp)
# R = tmp_sc * HP + c_p * I + c_c * D
crypto.hash_to_point_into(tmp, P[i])
crypto.add_keys3_into(R, tmp_sc, tmp, c_p, sI)
crypto.point_add_into(R, R, crypto.scalarmult_into(tmp, D, c_c))
chasher = c_to_hash.copy()
chasher.update(crypto.encodepoint_into(tmp_bf, L))
chasher.update(crypto.encodepoint_into(tmp_bf, R))
crypto.decodeint_into(c, chasher.digest())
P[i] = None
C_nonzero[i] = None
i = (i + 1) % len(P)
if i == 0:
crypto.sc_copy(sc1, c)
if i & 3 == 0:
gc.collect()
# Final scalar = a - c * (mu_P * p + mu_c * Z)
crypto.sc_mul_into(tmp_sc, mu_P, p)
crypto.sc_muladd_into(tmp_sc, mu_C, z, tmp_sc)
crypto.sc_mulsub_into(tmp_sc, c, tmp_sc, a)
crypto.encodeint_into(mg_buff[index + 1], tmp_sc)
mg_buff.append(crypto.encodeint(sc1))
mg_buff.append(sD)
return mg_buff