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1073 lines
44 KiB
1073 lines
44 KiB
#!/usr/bin/env python3 |
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""" |
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Lightning network interface for Electrum |
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Derived from https://gist.github.com/AdamISZ/046d05c156aaeb56cc897f85eecb3eb8 |
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""" |
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|
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from ecdsa.util import sigdecode_der, sigencode_string_canonize |
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from ecdsa import VerifyingKey |
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from ecdsa.curves import SECP256k1 |
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import subprocess |
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import queue |
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import traceback |
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import itertools |
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import json |
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from collections import OrderedDict, defaultdict |
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import asyncio |
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import sys |
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import os |
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import time |
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import binascii |
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import hashlib |
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import hmac |
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import cryptography.hazmat.primitives.ciphers.aead as AEAD |
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|
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from .bitcoin import (public_key_from_private_key, ser_to_point, point_to_ser, |
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string_to_number, deserialize_privkey, EC_KEY, rev_hex, int_to_hex, |
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push_script, script_num_to_hex, add_data_to_script, |
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add_number_to_script, var_int, witness_push) |
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from . import bitcoin |
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from . import constants |
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from . import transaction |
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from .util import PrintError, bh2u, print_error, bfh, profiler |
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from .transaction import opcodes, Transaction |
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|
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from collections import namedtuple |
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LocalCtxArgs = namedtuple("LocalCtxArgs", |
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["ctn", |
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"funding_pubkey", "remote_funding_pubkey", "remotepubkey", |
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"base_point", "remote_payment_basepoint", |
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"remote_revocation_pubkey", "local_delayedpubkey", "to_self_delay", |
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"funding_txid", "funding_index", "funding_satoshis", |
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"local_amount", "remote_amount", "dust_limit_satoshis"]) |
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|
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# hardcoded nodes |
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node_list = [ |
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('ecdsa.net', '9735', '038370f0e7a03eded3e1d41dc081084a87f0afa1c5b22090b4f3abb391eb15d8ff'), |
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('77.58.162.148', '9735', '022bb78ab9df617aeaaf37f6644609abb7295fad0c20327bccd41f8d69173ccb49') |
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] |
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|
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class LightningError(Exception): |
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pass |
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|
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message_types = {} |
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|
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def handlesingle(x, ma): |
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""" |
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Evaluate a term of the simple language used |
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to specify lightning message field lengths. |
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|
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If `x` is an integer, it is returned as is, |
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otherwise it is treated as a variable and |
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looked up in `ma`. |
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|
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It the value in `ma` was no integer, it is |
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assumed big-endian bytes and decoded. |
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|
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Returns int |
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""" |
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try: |
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x = int(x) |
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except ValueError: |
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x = ma[x] |
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try: |
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x = int(x) |
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except ValueError: |
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x = int.from_bytes(x, byteorder="big") |
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return x |
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|
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def calcexp(exp, ma): |
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""" |
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Evaluate simple mathematical expression given |
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in `exp` with variables assigned in the dict `ma` |
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|
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Returns int |
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""" |
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exp = str(exp) |
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if "*" in exp: |
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assert "+" not in exp |
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result = 1 |
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for term in exp.split("*"): |
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result *= handlesingle(term, ma) |
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return result |
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return sum(handlesingle(x, ma) for x in exp.split("+")) |
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|
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def make_handler(k, v): |
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""" |
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Generate a message handler function (taking bytes) |
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for message type `k` with specification `v` |
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|
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Check lib/lightning.json, `k` could be 'init', |
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and `v` could be |
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|
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{ type: 16, payload: { 'gflen': ..., ... }, ... } |
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|
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Returns function taking bytes |
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""" |
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def handler(data): |
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nonlocal k, v |
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ma = {} |
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pos = 0 |
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for fieldname in v["payload"]: |
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poslenMap = v["payload"][fieldname] |
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if "feature" in poslenMap: continue |
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#print(poslenMap["position"], ma) |
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assert pos == calcexp(poslenMap["position"], ma) |
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length = poslenMap["length"] |
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length = calcexp(length, ma) |
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ma[fieldname] = data[pos:pos+length] |
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pos += length |
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assert pos == len(data), (k, pos, len(data)) |
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return k, ma |
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return handler |
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|
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path = os.path.join(os.path.dirname(__file__), 'lightning.json') |
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with open(path) as f: |
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structured = json.loads(f.read(), object_pairs_hook=OrderedDict) |
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|
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for k in structured: |
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v = structured[k] |
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# these message types are skipped since their types collide |
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# (for example with pong, which also uses type=19) |
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# we don't need them yet |
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if k in ["final_incorrect_cltv_expiry", "final_incorrect_htlc_amount"]: |
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continue |
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if len(v["payload"]) == 0: |
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continue |
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try: |
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num = int(v["type"]) |
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except ValueError: |
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#print("skipping", k) |
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continue |
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byts = num.to_bytes(byteorder="big",length=2) |
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assert byts not in message_types, (byts, message_types[byts].__name__, k) |
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names = [x.__name__ for x in message_types.values()] |
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assert k + "_handler" not in names, (k, names) |
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message_types[byts] = make_handler(k, v) |
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message_types[byts].__name__ = k + "_handler" |
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|
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assert message_types[b"\x00\x10"].__name__ == "init_handler" |
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|
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def decode_msg(data): |
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""" |
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Decode Lightning message by reading the first |
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two bytes to determine message type. |
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|
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Returns message type string and parsed message contents dict |
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""" |
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typ = data[:2] |
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k, parsed = message_types[typ](data[2:]) |
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return k, parsed |
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|
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def gen_msg(msg_type, **kwargs): |
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""" |
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Encode kwargs into a Lightning message (bytes) |
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of the type given in the msg_type string |
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""" |
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typ = structured[msg_type] |
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data = int(typ["type"]).to_bytes(byteorder="big", length=2) |
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lengths = {} |
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for k in typ["payload"]: |
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poslenMap = typ["payload"][k] |
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if "feature" in poslenMap: continue |
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leng = calcexp(poslenMap["length"], lengths) |
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try: |
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clone = dict(lengths) |
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clone.update(kwargs) |
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leng = calcexp(poslenMap["length"], clone) |
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except KeyError: |
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pass |
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try: |
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param = kwargs[k] |
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except KeyError: |
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param = 0 |
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try: |
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if not isinstance(param, bytes): |
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assert isinstance(param, int), "field {} is neither bytes or int".format(k) |
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param = param.to_bytes(length=leng, byteorder="big") |
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except ValueError: |
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raise Exception("{} does not fit in {} bytes".format(k, leng)) |
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lengths[k] = len(param) |
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if lengths[k] != leng: |
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raise Exception("field {} is {} bytes long, should be {} bytes long".format(k, lengths[k], leng)) |
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data += param |
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return data |
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|
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def encode(n, s): |
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"""Return a bytestring version of the integer |
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value n, with a string length of s |
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""" |
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return n.to_bytes(length=s, byteorder="big") |
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|
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def H256(data): |
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return hashlib.sha256(data).digest() |
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|
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class HandshakeState(object): |
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prologue = b"lightning" |
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protocol_name = b"Noise_XK_secp256k1_ChaChaPoly_SHA256" |
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handshake_version = b"\x00" |
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def __init__(self, responder_pub): |
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self.responder_pub = responder_pub |
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self.h = H256(self.protocol_name) |
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self.ck = self.h |
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self.update(self.prologue) |
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self.update(self.responder_pub) |
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|
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def update(self, data): |
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self.h = H256(self.h + data) |
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return self.h |
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|
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def get_nonce_bytes(n): |
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"""BOLT 8 requires the nonce to be 12 bytes, 4 bytes leading |
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zeroes and 8 bytes little endian encoded 64 bit integer. |
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""" |
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nb = b"\x00"*4 |
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#Encode the integer as an 8 byte byte-string |
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nb2 = encode(n, 8) |
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nb2 = bytearray(nb2) |
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#Little-endian is required here |
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nb2.reverse() |
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return nb + nb2 |
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|
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def aead_encrypt(k, nonce, associated_data, data): |
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nonce_bytes = get_nonce_bytes(nonce) |
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a = AEAD.ChaCha20Poly1305(k) |
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return a.encrypt(nonce_bytes, data, associated_data) |
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|
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def aead_decrypt(k, nonce, associated_data, data): |
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nonce_bytes = get_nonce_bytes(nonce) |
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a = AEAD.ChaCha20Poly1305(k) |
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#raises InvalidTag exception if it's not valid |
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return a.decrypt(nonce_bytes, data, associated_data) |
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|
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def get_bolt8_hkdf(salt, ikm): |
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"""RFC5869 HKDF instantiated in the specific form |
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used in Lightning BOLT 8: |
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Extract and expand to 64 bytes using HMAC-SHA256, |
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with info field set to a zero length string as per BOLT8 |
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Return as two 32 byte fields. |
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""" |
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#Extract |
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prk = hmac.new(salt, msg=ikm, digestmod=hashlib.sha256).digest() |
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assert len(prk) == 32 |
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#Expand |
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info = b"" |
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T0 = b"" |
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T1 = hmac.new(prk, T0 + info + b"\x01", digestmod=hashlib.sha256).digest() |
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T2 = hmac.new(prk, T1 + info + b"\x02", digestmod=hashlib.sha256).digest() |
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assert len(T1 + T2) == 64 |
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return T1, T2 |
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|
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def get_ecdh(priv, pub): |
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s = string_to_number(priv) |
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pk = ser_to_point(pub) |
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pt = point_to_ser(pk * s) |
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return H256(pt) |
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|
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def act1_initiator_message(hs, my_privkey): |
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#Get a new ephemeral key |
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epriv, epub = create_ephemeral_key(my_privkey) |
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hs.update(epub) |
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ss = get_ecdh(epriv, hs.responder_pub) |
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ck2, temp_k1 = get_bolt8_hkdf(hs.ck, ss) |
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hs.ck = ck2 |
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c = aead_encrypt(temp_k1, 0, hs.h, b"") |
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#for next step if we do it |
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hs.update(c) |
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msg = hs.handshake_version + epub + c |
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assert len(msg) == 50 |
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return msg |
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|
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def privkey_to_pubkey(priv): |
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pub = public_key_from_private_key(priv[:32], True) |
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return bytes.fromhex(pub) |
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|
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def create_ephemeral_key(privkey): |
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pub = privkey_to_pubkey(privkey) |
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return (privkey[:32], pub) |
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|
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def get_unused_keys(): |
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xprv, xpub = bitcoin.bip32_root(b"testseed", "p2wpkh") |
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for i in itertools.count(): |
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childxprv, childxpub = bitcoin.bip32_private_derivation(xprv, "m/", "m/42/"+str(i)) |
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_, _, _, _, child_c, child_cK = bitcoin.deserialize_xpub(childxpub) |
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_, _, _, _, _, k = bitcoin.deserialize_xprv(childxprv) |
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assert len(k) == 32 |
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yield child_cK, k |
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|
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def aiosafe(f): |
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async def f2(*args, **kwargs): |
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try: |
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return await f(*args, **kwargs) |
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except: |
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# if the loop isn't stopped |
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# run_forever in network.py would not return, |
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# the asyncioThread would not die, |
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# and we would block on shutdown |
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asyncio.get_event_loop().stop() |
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traceback.print_exc() |
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return f2 |
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|
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def get_obscured_ctn(ctn, local, remote): |
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mask = int.from_bytes(H256(local + remote)[-6:], byteorder="big") |
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return ctn ^ mask |
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|
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def secret_to_pubkey(secret): |
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return point_to_ser(SECP256k1.generator * secret) |
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|
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def derive_pubkey(basepoint, per_commitment_point): |
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p = ser_to_point(basepoint) + SECP256k1.generator * bitcoin.string_to_number(bitcoin.sha256(per_commitment_point + basepoint)) |
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return point_to_ser(p) |
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|
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def derive_privkey(secret, per_commitment_point): |
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basepoint = point_to_ser(SECP256k1.generator * secret) |
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return secret + bitcoin.string_to_number(bitcoin.sha256(per_commitment_point + basepoint)) |
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|
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def derive_blinded_pubkey(basepoint, per_commitment_point): |
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k1 = ser_to_point(basepoint) * bitcoin.string_to_number(bitcoin.sha256(basepoint + per_commitment_point)) |
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k2 = ser_to_point(per_commitment_point) * bitcoin.string_to_number(bitcoin.sha256(per_commitment_point + basepoint)) |
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return point_to_ser(k1 + k2) |
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|
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|
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def get_per_commitment_secret_from_seed(seed: bytes, i: int, bits: int = 47) -> bytes: |
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"""Generate per commitment secret.""" |
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per_commitment_secret = bytearray(seed) |
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for bitindex in range(bits, -1, -1): |
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mask = 1 << bitindex |
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if i & mask: |
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per_commitment_secret[bitindex // 8] ^= 1 << (bitindex % 8) |
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per_commitment_secret = bytearray(bitcoin.sha256(per_commitment_secret)) |
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return bytes(per_commitment_secret) |
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|
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|
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def overall_weight(num_htlc): |
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return 500 + 172 * num_htlc + 224 |
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|
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HTLC_TIMEOUT_WEIGHT = 663 |
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HTLC_SUCCESS_WEIGHT = 703 |
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|
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def make_htlc_tx_output(amount_msat, local_feerate, revocationpubkey, local_delayedpubkey, success): |
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assert type(amount_msat) is int |
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assert type(local_feerate) is int |
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assert type(revocationpubkey) is bytes |
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assert type(local_delayedpubkey) is bytes |
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script = bytes([opcodes.OP_IF]) \ |
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+ bfh(push_script(bh2u(revocationpubkey))) \ |
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+ bytes([opcodes.OP_ELSE]) \ |
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+ bitcoin.add_number_to_script(144) \ |
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+ bytes([opcodes.OP_CSV, opcodes.OP_DROP]) \ |
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+ bfh(push_script(bh2u(local_delayedpubkey))) \ |
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+ bytes([opcodes.OP_ENDIF, opcodes.OP_CHECKSIG]) |
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|
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p2wsh = bitcoin.redeem_script_to_address('p2wsh', bh2u(script)) |
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weight = HTLC_SUCCESS_WEIGHT if success else HTLC_TIMEOUT_WEIGHT |
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fee = local_feerate * weight |
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output = (bitcoin.TYPE_ADDRESS, p2wsh, amount_msat // 1000 - fee) |
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return output |
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|
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def make_htlc_tx_witness(remotehtlcsig, localhtlcsig, payment_preimage, witness_script): |
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assert type(remotehtlcsig) is bytes |
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assert type(localhtlcsig) is bytes |
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assert type(payment_preimage) is bytes |
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assert type(witness_script) is bytes |
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return bfh(var_int(5) + '00' + ''.join([witness_push(bh2u(x)) for x in [remotehtlcsig, localhtlcsig, payment_preimage, witness_script]])) |
|
|
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def make_htlc_tx_inputs(htlc_output_txid, htlc_output_index, revocationpubkey, local_delayedpubkey, amount_msat, witness_script): |
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assert type(htlc_output_txid) is str |
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assert type(htlc_output_index) is int |
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assert type(revocationpubkey) is bytes |
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assert type(local_delayedpubkey) is bytes |
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assert type(amount_msat) is int |
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assert type(witness_script) is str |
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c_inputs = [{ |
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'scriptSig': '', |
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'type': 'p2wsh', |
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'signatures': [], |
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'num_sig': 0, |
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'prevout_n': htlc_output_index, |
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'prevout_hash': htlc_output_txid, |
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'value': amount_msat // 1000, |
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'coinbase': False, |
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'sequence': 0x0, |
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'preimage_script': witness_script, |
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}] |
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return c_inputs |
|
|
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def make_htlc_tx(cltv_timeout, inputs, output): |
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assert type(cltv_timeout) is int |
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c_outputs = [output] |
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tx = Transaction.from_io(inputs, c_outputs, locktime=cltv_timeout, version=2) |
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tx.BIP_LI01_sort() |
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return tx |
|
|
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def make_offered_htlc(revocation_pubkey, remote_htlcpubkey, local_htlcpubkey, payment_preimage): |
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assert type(revocation_pubkey) is bytes |
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assert type(remote_htlcpubkey) is bytes |
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assert type(local_htlcpubkey) is bytes |
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assert type(payment_preimage) is bytes |
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payment_hash = bitcoin.sha256(payment_preimage) |
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return bytes([opcodes.OP_DUP, opcodes.OP_HASH160]) + bfh(push_script(bh2u(bitcoin.hash_160(revocation_pubkey))))\ |
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+ bytes([opcodes.OP_EQUAL, opcodes.OP_IF, opcodes.OP_CHECKSIG, opcodes.OP_ELSE]) \ |
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+ bfh(push_script(bh2u(remote_htlcpubkey)))\ |
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+ bytes([opcodes.OP_SWAP, opcodes.OP_SIZE]) + bitcoin.add_number_to_script(32) + bytes([opcodes.OP_EQUAL, opcodes.OP_NOTIF, opcodes.OP_DROP])\ |
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+ bitcoin.add_number_to_script(2) + bytes([opcodes.OP_SWAP]) + bfh(push_script(bh2u(local_htlcpubkey))) + bitcoin.add_number_to_script(2)\ |
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+ bytes([opcodes.OP_CHECKMULTISIG, opcodes.OP_ELSE, opcodes.OP_HASH160])\ |
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+ bfh(push_script(bh2u(bitcoin.ripemd(payment_hash)))) + bytes([opcodes.OP_EQUALVERIFY, opcodes.OP_CHECKSIG, opcodes.OP_ENDIF, opcodes.OP_ENDIF]) |
|
|
|
def make_received_htlc(revocation_pubkey, remote_htlcpubkey, local_htlcpubkey, payment_preimage, cltv_expiry): |
|
for i in [revocation_pubkey, remote_htlcpubkey, local_htlcpubkey, payment_preimage]: |
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assert type(i) is bytes |
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assert type(cltv_expiry) is int |
|
|
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payment_hash = bitcoin.sha256(payment_preimage) |
|
return bytes([opcodes.OP_DUP, opcodes.OP_HASH160]) \ |
|
+ bfh(push_script(bh2u(bitcoin.hash_160(revocation_pubkey)))) \ |
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+ bytes([opcodes.OP_EQUAL, opcodes.OP_IF, opcodes.OP_CHECKSIG, opcodes.OP_ELSE]) \ |
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+ bfh(push_script(bh2u(remote_htlcpubkey))) \ |
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+ bytes([opcodes.OP_SWAP, opcodes.OP_SIZE]) \ |
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+ bitcoin.add_number_to_script(32) \ |
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+ bytes([opcodes.OP_EQUAL, opcodes.OP_IF, opcodes.OP_HASH160]) \ |
|
+ bfh(push_script(bh2u(bitcoin.ripemd(payment_hash)))) \ |
|
+ bytes([opcodes.OP_EQUALVERIFY]) \ |
|
+ bitcoin.add_number_to_script(2) \ |
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+ bytes([opcodes.OP_SWAP]) \ |
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+ bfh(push_script(bh2u(local_htlcpubkey))) \ |
|
+ bitcoin.add_number_to_script(2) \ |
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+ bytes([opcodes.OP_CHECKMULTISIG, opcodes.OP_ELSE, opcodes.OP_DROP]) \ |
|
+ bitcoin.add_number_to_script(cltv_expiry) \ |
|
+ bytes([opcodes.OP_CLTV, opcodes.OP_DROP, opcodes.OP_CHECKSIG, opcodes.OP_ENDIF, opcodes.OP_ENDIF]) |
|
|
|
|
|
def make_commitment(ctn, local_funding_pubkey, remote_funding_pubkey, remotepubkey, |
|
payment_basepoint, remote_payment_basepoint, |
|
revocation_pubkey, delayed_pubkey, to_self_delay, |
|
funding_txid, funding_pos, funding_satoshis, |
|
local_amount, remote_amount, dust_limit_satoshis, htlcs=[]): |
|
pubkeys = sorted([bh2u(local_funding_pubkey), bh2u(remote_funding_pubkey)]) |
|
obs = get_obscured_ctn(ctn, payment_basepoint, remote_payment_basepoint) |
|
locktime = (0x20 << 24) + (obs & 0xffffff) |
|
sequence = (0x80 << 24) + (obs >> 24) |
|
print_error('locktime', locktime, hex(locktime)) |
|
# commitment tx input |
|
c_inputs = [{ |
|
'type': 'p2wsh', |
|
'x_pubkeys': pubkeys, |
|
'signatures':[None, None], |
|
'num_sig': 2, |
|
'prevout_n': funding_pos, |
|
'prevout_hash': funding_txid, |
|
'value': funding_satoshis, |
|
'coinbase': False, |
|
'sequence':sequence |
|
}] |
|
# commitment tx outputs |
|
local_script = bytes([opcodes.OP_IF]) + bfh(push_script(bh2u(revocation_pubkey))) + bytes([opcodes.OP_ELSE]) + add_number_to_script(to_self_delay) \ |
|
+ bytes([opcodes.OP_CSV, opcodes.OP_DROP]) + bfh(push_script(bh2u(delayed_pubkey))) + bytes([opcodes.OP_ENDIF, opcodes.OP_CHECKSIG]) |
|
local_address = bitcoin.redeem_script_to_address('p2wsh', bh2u(local_script)) |
|
remote_address = bitcoin.pubkey_to_address('p2wpkh', bh2u(remotepubkey)) |
|
to_local = (bitcoin.TYPE_ADDRESS, local_address, local_amount) |
|
to_remote = (bitcoin.TYPE_ADDRESS, remote_address, remote_amount) |
|
c_outputs = [to_local, to_remote] |
|
for script, msat_amount in htlcs: |
|
c_outputs += [(bitcoin.TYPE_ADDRESS, bitcoin.redeem_script_to_address('p2wsh', bh2u(script)), msat_amount // 1000)] |
|
# trim outputs |
|
c_outputs = list(filter(lambda x:x[2]>= dust_limit_satoshis, c_outputs)) |
|
# create commitment tx |
|
tx = Transaction.from_io(c_inputs, c_outputs, locktime=locktime, version=2) |
|
tx.BIP_LI01_sort() |
|
return tx |
|
|
|
class Peer(PrintError): |
|
|
|
def __init__(self, host, port, pubkey, request_initial_sync=False, network=None): |
|
self.host = host |
|
self.port = port |
|
self.privkey = os.urandom(32) + b"\x01" |
|
self.pubkey = pubkey |
|
self.network = network |
|
self.read_buffer = b'' |
|
self.ping_time = 0 |
|
self.futures = ["channel_accepted", |
|
"funding_signed", |
|
"local_funding_locked", |
|
"remote_funding_locked", |
|
"commitment_signed"] |
|
self.channel_accepted = {} |
|
self.funding_signed = {} |
|
self.local_funding_locked = {} |
|
self.remote_funding_locked = {} |
|
self.commitment_signed = {} |
|
self.initialized = asyncio.Future() |
|
self.localfeatures = (0x08 if request_initial_sync else 0) |
|
# view of the network |
|
self.nodes = {} # received node announcements |
|
self.channel_db = ChannelDB() |
|
self.path_finder = LNPathFinder(self.channel_db) |
|
self.unfulfilled_htlcs = [] |
|
|
|
def diagnostic_name(self): |
|
return self.host |
|
|
|
def ping_if_required(self): |
|
if time.time() - self.ping_time > 120: |
|
self.send_message(gen_msg('ping', num_pong_bytes=4, byteslen=4)) |
|
self.ping_time = time.time() |
|
|
|
def send_message(self, msg): |
|
message_type, payload = decode_msg(msg) |
|
self.print_error("Sending '%s'"%message_type.upper(), payload) |
|
l = encode(len(msg), 2) |
|
lc = aead_encrypt(self.sk, self.sn(), b'', l) |
|
c = aead_encrypt(self.sk, self.sn(), b'', msg) |
|
assert len(lc) == 18 |
|
assert len(c) == len(msg) + 16 |
|
self.writer.write(lc+c) |
|
|
|
async def read_message(self): |
|
rn_l, rk_l = self.rn() |
|
rn_m, rk_m = self.rn() |
|
while True: |
|
s = await self.reader.read(2**10) |
|
if not s: |
|
raise Exception('connection closed') |
|
self.read_buffer += s |
|
if len(self.read_buffer) < 18: |
|
continue |
|
lc = self.read_buffer[:18] |
|
l = aead_decrypt(rk_l, rn_l, b'', lc) |
|
length = int.from_bytes(l, byteorder="big") |
|
offset = 18 + length + 16 |
|
if len(self.read_buffer) < offset: |
|
continue |
|
c = self.read_buffer[18:offset] |
|
self.read_buffer = self.read_buffer[offset:] |
|
msg = aead_decrypt(rk_m, rn_m, b'', c) |
|
return msg |
|
|
|
async def handshake(self): |
|
hs = HandshakeState(self.pubkey) |
|
msg = act1_initiator_message(hs, self.privkey) |
|
# act 1 |
|
self.writer.write(msg) |
|
rspns = await self.reader.read(2**10) |
|
assert len(rspns) == 50 |
|
hver, alice_epub, tag = rspns[0], rspns[1:34], rspns[34:] |
|
assert bytes([hver]) == hs.handshake_version |
|
# act 2 |
|
hs.update(alice_epub) |
|
myepriv, myepub = create_ephemeral_key(self.privkey) |
|
ss = get_ecdh(myepriv, alice_epub) |
|
ck, temp_k2 = get_bolt8_hkdf(hs.ck, ss) |
|
hs.ck = ck |
|
p = aead_decrypt(temp_k2, 0, hs.h, tag) |
|
hs.update(tag) |
|
# act 3 |
|
my_pubkey = privkey_to_pubkey(self.privkey) |
|
c = aead_encrypt(temp_k2, 1, hs.h, my_pubkey) |
|
hs.update(c) |
|
ss = get_ecdh(self.privkey[:32], alice_epub) |
|
ck, temp_k3 = get_bolt8_hkdf(hs.ck, ss) |
|
hs.ck = ck |
|
t = aead_encrypt(temp_k3, 0, hs.h, b'') |
|
self.sk, self.rk = get_bolt8_hkdf(hs.ck, b'') |
|
msg = hs.handshake_version + c + t |
|
self.writer.write(msg) |
|
# init counters |
|
self._sn = 0 |
|
self._rn = 0 |
|
self.r_ck = ck |
|
self.s_ck = ck |
|
|
|
def rn(self): |
|
o = self._rn, self.rk |
|
self._rn += 1 |
|
if self._rn == 1000: |
|
self.r_ck, self.rk = get_bolt8_hkdf(self.r_ck, self.rk) |
|
self._rn = 0 |
|
return o |
|
|
|
def sn(self): |
|
o = self._sn |
|
self._sn += 1 |
|
if self._sn == 1000: |
|
self.s_ck, self.sk = get_bolt8_hkdf(self.s_ck, self.sk) |
|
self._sn = 0 |
|
return o |
|
|
|
def process_message(self, message): |
|
message_type, payload = decode_msg(message) |
|
try: |
|
f = getattr(self, 'on_' + message_type) |
|
except AttributeError: |
|
self.print_error("Received '%s'" % message_type.upper(), payload) |
|
return |
|
# raw message is needed to check signature |
|
if message_type=='node_announcement': |
|
payload['raw'] = message |
|
f(payload) |
|
|
|
def on_error(self, payload): |
|
for i in self.futures: |
|
if payload["channel_id"] in getattr(self, i): |
|
getattr(self, i)[payload["channel_id"]].set_exception(LightningError(payload["data"])) |
|
return |
|
self.print_error("no future found to resolve", payload) |
|
|
|
def on_ping(self, payload): |
|
l = int.from_bytes(payload['num_pong_bytes'], byteorder="big") |
|
self.send_message(gen_msg('pong', byteslen=l)) |
|
|
|
def on_accept_channel(self, payload): |
|
self.channel_accepted[payload["temporary_channel_id"]].set_result(payload) |
|
|
|
def on_funding_signed(self, payload): |
|
channel_id = int.from_bytes(payload['channel_id'], byteorder="big") |
|
self.funding_signed[channel_id].set_result(payload) |
|
|
|
def on_funding_locked(self, payload): |
|
channel_id = int.from_bytes(payload['channel_id'], byteorder="big") |
|
self.remote_funding_locked[channel_id].set_result(payload) |
|
|
|
def on_node_announcement(self, payload): |
|
pubkey = payload['node_id'] |
|
signature = payload['signature'] |
|
h = bitcoin.Hash(payload['raw'][66:]) |
|
if not bitcoin.verify_signature(pubkey, signature, h): |
|
return False |
|
self.s = payload['addresses'] |
|
def read(n): |
|
data, self.s = self.s[0:n], self.s[n:] |
|
return data |
|
addresses = [] |
|
while self.s: |
|
atype = ord(read(1)) |
|
if atype == 0: |
|
pass |
|
elif atype == 1: |
|
ipv4_addr = '.'.join(map(lambda x: '%d'%x, read(4))) |
|
port = int.from_bytes(read(2), byteorder="big") |
|
x = ipv4_addr, port, binascii.hexlify(pubkey) |
|
addresses.append((ipv4_addr, port)) |
|
elif atype == 2: |
|
ipv6_addr = b':'.join([binascii.hexlify(read(2)) for i in range(4)]) |
|
port = int.from_bytes(read(2), byteorder="big") |
|
addresses.append((ipv6_addr, port)) |
|
else: |
|
pass |
|
continue |
|
alias = payload['alias'].rstrip(b'\x00') |
|
self.nodes[pubkey] = { |
|
'alias': alias, |
|
'addresses': addresses |
|
} |
|
self.print_error('node announcement', binascii.hexlify(pubkey), alias, addresses) |
|
|
|
def on_init(self, payload): |
|
pass |
|
|
|
def on_channel_update(self, payload): |
|
self.channel_db.on_channel_update(payload) |
|
|
|
def on_channel_announcement(self, payload): |
|
self.channel_db.on_channel_announcement(payload) |
|
|
|
#def open_channel(self, funding_sat, push_msat): |
|
# self.send_message(gen_msg('open_channel', funding_satoshis=funding_sat, push_msat=push_msat)) |
|
|
|
@aiosafe |
|
async def main_loop(self): |
|
self.reader, self.writer = await asyncio.open_connection(self.host, self.port) |
|
await self.handshake() |
|
# send init |
|
self.send_message(gen_msg("init", gflen=0, lflen=1, localfeatures=self.localfeatures)) |
|
# read init |
|
msg = await self.read_message() |
|
self.process_message(msg) |
|
# initialized |
|
self.initialized.set_result(msg) |
|
# loop |
|
while True: |
|
self.ping_if_required() |
|
msg = await self.read_message() |
|
self.process_message(msg) |
|
# close socket |
|
self.print_error('closing lnbase') |
|
self.writer.close() |
|
|
|
@aiosafe |
|
async def channel_establishment_flow(self, wallet, config, funding_satoshis, push_msat): |
|
await self.initialized |
|
temp_channel_id = os.urandom(32) |
|
keys = get_unused_keys() |
|
funding_pubkey, funding_privkey = next(keys) |
|
revocation_basepoint, revocation_privkey = next(keys) |
|
htlc_basepoint, htlc_privkey = next(keys) |
|
delayed_payment_basepoint, delayed_privkey = next(keys) |
|
base_secret = 0x000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f |
|
per_commitment_secret_seed = 0x1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100.to_bytes(length=32, byteorder="big") |
|
per_commitment_secret_index = 2**48 - 1 |
|
# amounts |
|
local_feerate = 20000 |
|
dust_limit_satoshis = 10 |
|
to_self_delay = 144 |
|
ctn = 0 |
|
# |
|
base_point = secret_to_pubkey(base_secret) |
|
per_commitment_secret_first = get_per_commitment_secret_from_seed(per_commitment_secret_seed, per_commitment_secret_index) |
|
per_commitment_point_first = secret_to_pubkey(int.from_bytes( |
|
per_commitment_secret_first, |
|
byteorder="big")) |
|
msg = gen_msg( |
|
"open_channel", |
|
temporary_channel_id=temp_channel_id, |
|
chain_hash=bytes.fromhex(rev_hex(constants.net.GENESIS)), |
|
funding_satoshis=funding_satoshis, |
|
push_msat=push_msat, |
|
dust_limit_satoshis=dust_limit_satoshis, |
|
feerate_per_kw=local_feerate, |
|
max_accepted_htlcs=5, |
|
funding_pubkey=funding_pubkey, |
|
revocation_basepoint=revocation_basepoint, |
|
htlc_basepoint=htlc_basepoint, |
|
payment_basepoint=base_point, |
|
delayed_payment_basepoint=delayed_payment_basepoint, |
|
first_per_commitment_point=per_commitment_point_first, |
|
to_self_delay=to_self_delay, |
|
max_htlc_value_in_flight_msat=10_000 |
|
) |
|
self.channel_accepted[temp_channel_id] = asyncio.Future() |
|
self.send_message(msg) |
|
try: |
|
payload = await self.channel_accepted[temp_channel_id] |
|
finally: |
|
del self.channel_accepted[temp_channel_id] |
|
remote_per_commitment_point = payload['first_per_commitment_point'] |
|
remote_funding_pubkey = payload["funding_pubkey"] |
|
remote_delay = int.from_bytes(payload['to_self_delay'], byteorder="big") |
|
remote_dust_limit_satoshis = int.from_bytes(payload['dust_limit_satoshis'], byteorder="big") |
|
remote_revocation_basepoint = payload['revocation_basepoint'] |
|
remote_payment_basepoint = payload['payment_basepoint'] |
|
remote_delayed_payment_basepoint = payload['delayed_payment_basepoint'] |
|
funding_txn_minimum_depth = int.from_bytes(payload['minimum_depth'], byteorder="big") |
|
self.print_error('remote dust limit', remote_dust_limit_satoshis) |
|
self.print_error('remote delay', remote_delay) |
|
self.print_error('funding_txn_minimum_depth', funding_txn_minimum_depth) |
|
# create funding tx |
|
pubkeys = sorted([bh2u(funding_pubkey), bh2u(remote_funding_pubkey)]) |
|
redeem_script = transaction.multisig_script(pubkeys, 2) |
|
funding_address = bitcoin.redeem_script_to_address('p2wsh', redeem_script) |
|
funding_output = (bitcoin.TYPE_ADDRESS, funding_address, funding_satoshis) |
|
funding_tx = wallet.mktx([funding_output], None, config, 1000) |
|
funding_txid = funding_tx.txid() |
|
funding_index = funding_tx.outputs().index(funding_output) |
|
# derive keys |
|
localpubkey = derive_pubkey(base_point, remote_per_commitment_point) |
|
localprivkey = derive_privkey(base_secret, remote_per_commitment_point) |
|
remotepubkey = derive_pubkey(remote_payment_basepoint, per_commitment_point_first) |
|
revocation_pubkey = derive_blinded_pubkey(revocation_basepoint, remote_per_commitment_point) |
|
remote_revocation_pubkey = derive_blinded_pubkey(remote_revocation_basepoint, per_commitment_point_first) |
|
local_delayedpubkey = derive_pubkey(delayed_payment_basepoint, per_commitment_point_first) |
|
remote_delayedpubkey = derive_pubkey(remote_delayed_payment_basepoint, remote_per_commitment_point) |
|
# compute amounts |
|
htlcs = [] |
|
fee = local_feerate * overall_weight(len(htlcs)) // 1000 |
|
to_local_msat = funding_satoshis*1000 - push_msat |
|
to_remote_msat = push_msat |
|
local_amount = to_local_msat // 1000 - fee |
|
remote_amount = to_remote_msat // 1000 |
|
# remote commitment transaction |
|
remote_ctx = make_commitment( |
|
ctn, |
|
remote_funding_pubkey, funding_pubkey, localpubkey, |
|
base_point, remote_payment_basepoint, |
|
revocation_pubkey, remote_delayedpubkey, remote_delay, |
|
funding_txid, funding_index, funding_satoshis, |
|
remote_amount, local_amount, remote_dust_limit_satoshis) |
|
remote_ctx.sign({bh2u(funding_pubkey): (funding_privkey, True)}) |
|
sig_index = pubkeys.index(bh2u(funding_pubkey)) |
|
sig = bytes.fromhex(remote_ctx.inputs()[0]["signatures"][sig_index]) |
|
r, s = sigdecode_der(sig[:-1], SECP256k1.generator.order()) |
|
sig_64 = sigencode_string_canonize(r, s, SECP256k1.generator.order()) |
|
funding_txid_bytes = bytes.fromhex(funding_txid)[::-1] |
|
channel_id = int.from_bytes(funding_txid_bytes, byteorder="big") ^ funding_index |
|
self.send_message(gen_msg("funding_created", temporary_channel_id=temp_channel_id, funding_txid=funding_txid_bytes, funding_output_index=funding_index, signature=sig_64)) |
|
self.funding_signed[channel_id] = asyncio.Future() |
|
try: |
|
payload = await self.funding_signed[channel_id] |
|
finally: |
|
del self.funding_signed[channel_id] |
|
self.print_error('received funding_signed') |
|
remote_sig = payload['signature'] |
|
# verify remote signature |
|
local_ctx_args = LocalCtxArgs( |
|
ctn, |
|
funding_pubkey, remote_funding_pubkey, remotepubkey, |
|
base_point, remote_payment_basepoint, |
|
remote_revocation_pubkey, local_delayedpubkey, to_self_delay, |
|
funding_txid, funding_index, funding_satoshis, |
|
local_amount, remote_amount, dust_limit_satoshis) |
|
local_ctx = make_commitment(*local_ctx_args) |
|
pre_hash = bitcoin.Hash(bfh(local_ctx.serialize_preimage(0))) |
|
if not bitcoin.verify_signature(remote_funding_pubkey, remote_sig, pre_hash): |
|
raise Exception('verifying remote signature failed.') |
|
# broadcast funding tx |
|
self.local_funding_locked[channel_id] = asyncio.Future() |
|
self.remote_funding_locked[channel_id] = asyncio.Future() |
|
success, _txid = self.network.broadcast(funding_tx) |
|
assert success, success |
|
# wait until we see confirmations |
|
def on_network_update(event, *args): |
|
conf = wallet.get_tx_height(funding_txid)[1] |
|
if conf >= funding_txn_minimum_depth: |
|
async def set_local_funding_locked_result(): |
|
try: |
|
self.local_funding_locked[channel_id].set_result(1) |
|
except (asyncio.InvalidStateError, KeyError) as e: |
|
# FIXME race condition if updates come in quickly, set_result might be called multiple times |
|
# or self.local_funding_locked[channel_id] might be deleted already |
|
self.print_error('local_funding_locked.set_result error for channel {}: {}'.format(channel_id, e)) |
|
asyncio.run_coroutine_threadsafe(set_local_funding_locked_result(), asyncio.get_event_loop()) |
|
self.network.unregister_callback(on_network_update) |
|
self.network.register_callback(on_network_update, ['updated']) # thread safe |
|
|
|
try: |
|
await self.local_funding_locked[channel_id] |
|
finally: |
|
del self.local_funding_locked[channel_id] |
|
per_commitment_secret_index -= 1 |
|
per_commitment_point_second = secret_to_pubkey(int.from_bytes( |
|
get_per_commitment_secret_from_seed(per_commitment_secret_seed, per_commitment_secret_index), |
|
byteorder="big")) |
|
self.send_message(gen_msg("funding_locked", channel_id=channel_id, next_per_commitment_point=per_commitment_point_second)) |
|
# wait until we receive funding_locked |
|
try: |
|
payload = await self.remote_funding_locked[channel_id] |
|
finally: |
|
del self.remote_funding_locked[channel_id] |
|
self.print_error('Done waiting for remote_funding_locked', payload) |
|
self.commitment_signed[channel_id] = asyncio.Future() |
|
return channel_id, per_commitment_secret_seed, local_ctx_args, remote_funding_pubkey |
|
async def receive_commitment_revoke_ack(self, channel_id, per_commitment_secret_seed, last_pcs_index, local_ctx_args, expected_received_sat, remote_funding_pubkey, next_commitment_number): |
|
try: |
|
commitment_signed_msg = await self.commitment_signed[channel_id] |
|
finally: |
|
del self.commitment_signed[channel_id] |
|
# TODO make new future? (there could be more updates) |
|
|
|
local_ctx_args = local_ctx_args._replace(local_amount = local_ctx_args.local_amount + expected_received_sat) |
|
local_ctx_args = local_ctx_args._replace(remote_amount = local_ctx_args.remote_amount - expected_received_sat) |
|
local_ctx_args = local_ctx_args._replace(ctn = next_commitment_number) |
|
new_commitment = make_commitment(*local_ctx_args) |
|
pre_hash = bitcoin.Hash(bfh(new_commitment.serialize_preimage(0))) |
|
if not bitcoin.verify_signature(remote_funding_pubkey, commitment_signed_msg["signature"], pre_hash): |
|
raise Exception('failed verifying signature of updated commitment transaction') |
|
|
|
last_per_commitment_secret = get_per_commitment_secret_from_seed(per_commitment_secret_seed, last_pcs_index) |
|
|
|
next_per_commitment_secret = get_per_commitment_secret_from_seed(per_commitment_secret_seed, last_pcs_index - 1) |
|
next_per_commitment_point = secret_to_pubkey(int.from_bytes( |
|
next_per_commitment_secret, |
|
byteorder="big")) |
|
|
|
self.send_message(gen_msg("revoke_and_ack", channel_id=channel_id, per_commitment_secret=last_per_commitment_secret, next_per_commitment_point=next_per_commitment_point)) |
|
|
|
async def fulfill_htlc(self, channel_id, htlc_id, payment_preimage): |
|
self.send_message(gen_msg("update_fulfill_htlc", channel_id=channel_id, id=htlc_id, payment_preimage=payment_preimage)) |
|
|
|
def on_commitment_signed(self, payload): |
|
channel_id = int.from_bytes(payload['channel_id'], byteorder="big") |
|
self.commitment_signed[channel_id].set_result(payload) |
|
|
|
def on_update_add_htlc(self, payload): |
|
# no onion routing for the moment: we assume we are the end node |
|
self.print_error('on_update_add_htlc', payload) |
|
assert self.unfulfilled_htlcs == [] |
|
self.unfulfilled_htlcs.append(payload) |
|
|
|
|
|
|
|
# replacement for lightningCall |
|
class LNWorker: |
|
|
|
def __init__(self, wallet, network): |
|
self.wallet = wallet |
|
self.network = network |
|
host, port, pubkey = network.config.get('lightning_peer', node_list[0]) |
|
pubkey = binascii.unhexlify(pubkey) |
|
port = int(port) |
|
self.peer = Peer(host, port, pubkey) |
|
self.network.futures.append(asyncio.run_coroutine_threadsafe(self.peer.main_loop(), asyncio.get_event_loop())) |
|
|
|
def openchannel(self): |
|
# todo: get utxo from wallet |
|
# submit coro to asyncio main loop |
|
self.peer.open_channel() |
|
|
|
|
|
class ChannelInfo(PrintError): |
|
|
|
def __init__(self, channel_announcement_payload): |
|
self.channel_id = channel_announcement_payload['short_channel_id'] |
|
self.node_id_1 = channel_announcement_payload['node_id_1'] |
|
self.node_id_2 = channel_announcement_payload['node_id_2'] |
|
|
|
self.capacity_sat = None |
|
self.policy_node1 = None |
|
self.policy_node2 = None |
|
|
|
def set_capacity(self, capacity): |
|
# TODO call this after looking up UTXO for funding txn on chain |
|
self.capacity_sat = capacity |
|
|
|
def on_channel_update(self, msg_payload): |
|
assert self.channel_id == msg_payload['short_channel_id'] |
|
flags = int.from_bytes(msg_payload['flags'], byteorder="big") |
|
direction = bool(flags & 1) |
|
if direction == 0: |
|
self.policy_node1 = ChannelInfoDirectedPolicy(msg_payload) |
|
else: |
|
self.policy_node2 = ChannelInfoDirectedPolicy(msg_payload) |
|
self.print_error('channel update', binascii.hexlify(self.channel_id), flags) |
|
|
|
def get_policy_for_node(self, node_id): |
|
if node_id == self.node_id_1: |
|
return self.policy_node1 |
|
elif node_id == self.node_id_2: |
|
return self.policy_node2 |
|
else: |
|
raise Exception('node_id {} not in channel {}'.format(node_id, self.channel_id)) |
|
|
|
|
|
class ChannelInfoDirectedPolicy: |
|
|
|
def __init__(self, channel_update_payload): |
|
self.cltv_expiry_delta = channel_update_payload['cltv_expiry_delta'] |
|
self.htlc_minimum_msat = channel_update_payload['htlc_minimum_msat'] |
|
self.fee_base_msat = channel_update_payload['fee_base_msat'] |
|
self.fee_proportional_millionths = channel_update_payload['fee_proportional_millionths'] |
|
|
|
|
|
class ChannelDB(PrintError): |
|
|
|
def __init__(self): |
|
self._id_to_channel_info = {} |
|
self._channels_for_node = defaultdict(set) # node -> set(short_channel_id) |
|
|
|
def get_channel_info(self, channel_id): |
|
return self._id_to_channel_info.get(channel_id, None) |
|
|
|
def get_channels_for_node(self, node_id): |
|
"""Returns the set of channels that have node_id as one of the endpoints.""" |
|
return self._channels_for_node[node_id] |
|
|
|
def on_channel_announcement(self, msg_payload): |
|
short_channel_id = msg_payload['short_channel_id'] |
|
self.print_error('channel announcement', binascii.hexlify(short_channel_id)) |
|
channel_info = ChannelInfo(msg_payload) |
|
self._id_to_channel_info[short_channel_id] = channel_info |
|
self._channels_for_node[channel_info.node_id_1].add(short_channel_id) |
|
self._channels_for_node[channel_info.node_id_2].add(short_channel_id) |
|
|
|
def on_channel_update(self, msg_payload): |
|
short_channel_id = msg_payload['short_channel_id'] |
|
try: |
|
channel_info = self._id_to_channel_info[short_channel_id] |
|
except KeyError: |
|
pass # ignore channel update |
|
else: |
|
channel_info.on_channel_update(msg_payload) |
|
|
|
def remove_channel(self, short_channel_id): |
|
try: |
|
channel_info = self._id_to_channel_info[short_channel_id] |
|
except KeyError: |
|
self.print_error('cannot find channel {}'.format(short_channel_id)) |
|
return |
|
self._id_to_channel_info.pop(short_channel_id, None) |
|
for node in (channel_info.node_id_1, channel_info.node_id_2): |
|
try: |
|
self._channels_for_node[node].remove(short_channel_id) |
|
except KeyError: |
|
pass |
|
|
|
|
|
class LNPathFinder(PrintError): |
|
|
|
def __init__(self, channel_db): |
|
self.channel_db = channel_db |
|
|
|
def _edge_cost(self, short_channel_id, start_node, payment_amt_msat): |
|
"""Heuristic cost of going through a channel. |
|
direction: 0 or 1. --- 0 means node_id_1 -> node_id_2 |
|
""" |
|
channel_info = self.channel_db.get_channel_info(short_channel_id) |
|
if channel_info is None: |
|
return float('inf') |
|
|
|
channel_policy = channel_info.get_policy_for_node(start_node) |
|
cltv_expiry_delta = channel_policy.cltv_expiry_delta |
|
htlc_minimum_msat = channel_policy.htlc_minimum_msat |
|
fee_base_msat = channel_policy.fee_base_msat |
|
fee_proportional_millionths = channel_policy.fee_proportional_millionths |
|
if payment_amt_msat is not None: |
|
if payment_amt_msat < htlc_minimum_msat: |
|
return float('inf') # payment amount too little |
|
if channel_info.capacity_sat is not None and \ |
|
payment_amt_msat // 1000 > channel_info.capacity_sat: |
|
return float('inf') # payment amount too large |
|
amt = payment_amt_msat or 50000 * 1000 # guess for typical payment amount |
|
fee_msat = fee_base_msat + amt * fee_proportional_millionths / 1000000 |
|
# TODO revise |
|
# paying 10 more satoshis ~ waiting one more block |
|
fee_cost = fee_msat / 1000 / 10 |
|
cltv_cost = cltv_expiry_delta |
|
return cltv_cost + fee_cost + 1 |
|
|
|
@profiler |
|
def find_path_for_payment(self, from_node_id, to_node_id, amount_msat=None): |
|
"""Return a path between from_node_id and to_node_id. |
|
|
|
Returns a list of (node_id, short_channel_id) representing a path. |
|
To get from node ret[n][0] to ret[n+1][0], use channel ret[n][1] |
|
""" |
|
# TODO find multiple paths?? |
|
|
|
# run Dijkstra |
|
distance_from_start = defaultdict(lambda: float('inf')) |
|
distance_from_start[from_node_id] = 0 |
|
prev_node = {} |
|
nodes_to_explore = queue.PriorityQueue() |
|
nodes_to_explore.put((0, from_node_id)) |
|
|
|
while nodes_to_explore.qsize() > 0: |
|
dist_to_cur_node, cur_node = nodes_to_explore.get() |
|
if cur_node == to_node_id: |
|
break |
|
if dist_to_cur_node != distance_from_start[cur_node]: |
|
# queue.PriorityQueue does not implement decrease_priority, |
|
# so instead of decreasing priorities, we add items again into the queue. |
|
# so there are duplicates in the queue, that we discard now: |
|
continue |
|
for edge_channel_id in self.channel_db.get_channels_for_node(cur_node): |
|
channel_info = self.channel_db.get_channel_info(edge_channel_id) |
|
node1, node2 = channel_info.node_id_1, channel_info.node_id_2 |
|
neighbour = node2 if node1 == cur_node else node1 |
|
alt_dist_to_neighbour = distance_from_start[cur_node] \ |
|
+ self._edge_cost(edge_channel_id, cur_node, amount_msat) |
|
if alt_dist_to_neighbour < distance_from_start[neighbour]: |
|
distance_from_start[neighbour] = alt_dist_to_neighbour |
|
prev_node[neighbour] = cur_node, edge_channel_id |
|
nodes_to_explore.put((alt_dist_to_neighbour, neighbour)) |
|
else: |
|
return None # no path found |
|
|
|
# backtrack from end to start |
|
cur_node = to_node_id |
|
path = [(cur_node, None)] |
|
while cur_node != from_node_id: |
|
cur_node, edge_taken = prev_node[cur_node] |
|
path += [(cur_node, edge_taken)] |
|
path.reverse() |
|
return path
|
|
|