def compute_hash(rr: MoneroTransferDetails) -> bytes: kck = crypto.get_keccak() kck.update(rr.out_key) kck.update(rr.tx_pub_key) if rr.additional_tx_pub_keys: for x in rr.additional_tx_pub_keys: kck.update(x) kck.update(dump_uvarint_b(rr.internal_output_index)) return kck.digest()
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
def generate_mlsag( message: bytes, pk: KeyM, xx: List[Sc25519], index: int, dsRows: int, mg_buff: List[bytes], ) -> List[bytes]: """ Multilayered Spontaneous Anonymous Group Signatures (MLSAG signatures) :param message: the full message to be signed (actually its hash) :param pk: matrix of public keys and commitments :param xx: input secret array composed of a private key and commitment mask :param index: specifies corresponding public key to the `xx`'s private key in the `pk` array :param dsRows: separates pubkeys from commitment :param mg_buff: mg signature buffer """ rows, cols = gen_mlsag_assert(pk, xx, index, dsRows) rows_b_size = int_serialize.uvarint_size(rows) # Preallocation of the chunked buffer, len + cols + cc for _ in range(1 + cols + 1): mg_buff.append(None) mg_buff[0] = int_serialize.dump_uvarint_b(cols) cc = crypto.new_scalar() # rv.cc c = crypto.new_scalar() L = crypto.new_point() R = crypto.new_point() Hi = crypto.new_point() # calculates the "first" c, key images and random scalars alpha c_old, II, alpha = generate_first_c_and_key_images(message, pk, xx, index, dsRows, rows, cols) i = (index + 1) % cols if i == 0: crypto.sc_copy(cc, c_old) ss = [crypto.new_scalar() for _ in range(rows)] tmp_buff = bytearray(32) while i != index: hasher = _hasher_message(message) # Serialize size of the row mg_buff[i + 1] = bytearray(rows_b_size + 32 * rows) int_serialize.dump_uvarint_b_into(rows, mg_buff[i + 1]) for x in ss: crypto.random_scalar(x) for j in range(dsRows): # L = rv.ss[i][j] * G + c_old * pk[i][j] crypto.add_keys2_into(L, ss[j], c_old, crypto.decodepoint_into(Hi, pk[i][j])) crypto.hash_to_point_into(Hi, pk[i][j]) # R = rv.ss[i][j] * H(pk[i][j]) + c_old * Ip[j] crypto.add_keys3_into(R, ss[j], Hi, c_old, II[j]) hasher.update(pk[i][j]) _hash_point(hasher, L, tmp_buff) _hash_point(hasher, R, tmp_buff) for j in range(dsRows, rows): # again, omitting R here as discussed above crypto.add_keys2_into(L, ss[j], c_old, crypto.decodepoint_into(Hi, pk[i][j])) hasher.update(pk[i][j]) _hash_point(hasher, L, tmp_buff) for si in range(rows): crypto.encodeint_into(mg_buff[i + 1], ss[si], rows_b_size + 32 * si) crypto.decodeint_into(c, hasher.digest()) crypto.sc_copy(c_old, c) pk[i] = None i = (i + 1) % cols if i == 0: crypto.sc_copy(cc, c_old) gc.collect() del II # Finalizing rv.ss by processing rv.ss[index] mg_buff[index + 1] = bytearray(rows_b_size + 32 * rows) int_serialize.dump_uvarint_b_into(rows, mg_buff[index + 1]) for j in range(rows): crypto.sc_mulsub_into(ss[j], c, xx[j], alpha[j]) crypto.encodeint_into(mg_buff[index + 1], ss[j], rows_b_size + 32 * j) # rv.cc mg_buff[-1] = crypto.encodeint(cc) return mg_buff