lnbase: create unit test for commitment tx

lib/lnbase.py

@@ -21,12 +21,12 @@ import hashlib
 import hmac
 import cryptography.hazmat.primitives.ciphers.aead as AEAD
 
-from .bitcoin import public_key_from_private_key, ser_to_point, point_to_ser, string_to_number, deserialize_privkey, EC_KEY, rev_hex
+from .bitcoin import public_key_from_private_key, ser_to_point, point_to_ser, string_to_number, deserialize_privkey, EC_KEY, rev_hex, int_to_hex
 from . import bitcoin
 from .constants import set_testnet, set_simnet
 from . import constants
 from . import transaction
-from .util import PrintError, bh2u
+from .util import PrintError, bh2u, print_error
 from .wallet import Wallet
 from .storage import WalletStorage
 from .transaction import opcodes, Transaction
@@ -248,6 +248,45 @@ def aiosafe(f):
             traceback.print_exc()
     return f2
 
+def get_locktime(cn, local, remote):
+    print_error(len(local), len(remote))
+    q = local + remote
+    mask = int.from_bytes(H256(q)[-6:], byteorder="big")
+    print_error('mask', hex(mask))
+    obs = cn ^ mask
+    print_error('obs ', hex(obs))
+    locktime = (0x20 << 48) + obs
+    return locktime
+
+def make_commitment(local_pubkey, remote_pubkey, payment_pubkey, remote_payment_pubkey, revocation_pubkey, delayed_pubkey, funding_txid, funding_pos, funding_satoshis):
+    pubkeys = sorted([bh2u(local_pubkey), bh2u(remote_pubkey)])
+    # 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
+    }]
+    # commitment tx outputs
+    local_script = bytes([opcodes.OP_IF]) + revocation_pubkey + bytes([opcodes.OP_ELSE, opcodes.OP_CSV, opcodes.OP_DROP]) + delayed_pubkey + bytes([opcodes.OP_ENDIF, opcodes.OP_CHECKSIG])
+    local_address = bitcoin.redeem_script_to_address('p2wsh', bh2u(local_script))
+    local_amount = funding_satoshis
+    remote_address = bitcoin.pubkey_to_address('p2wpkh', bh2u(remote_pubkey))
+    remote_amount = 0
+    to_local = (bitcoin.TYPE_ADDRESS, local_address, local_amount)
+    to_remote = (bitcoin.TYPE_ADDRESS, remote_address, remote_amount)
+    # no htlc for the moment
+    c_outputs = [to_local, to_remote]
+    # create commitment tx
+    locktime = get_locktime(0, payment_pubkey, remote_payment_pubkey)
+    print_error('locktime', locktime, hex(locktime))
+    tx = Transaction.from_io(c_inputs, c_outputs, locktime=locktime, version=2)
+    return tx
+
 class Peer(PrintError):
 
     def __init__(self, host, port, pubkey):
@@ -418,36 +457,13 @@ class Peer(PrintError):
         pubkeys = sorted([bh2u(funding_pubkey), bh2u(remote_pubkey)])
         redeem_script = transaction.multisig_script(pubkeys, 2)
         funding_address = bitcoin.redeem_script_to_address('p2wsh', redeem_script)
-        #TODO support passwd, fix fee
         funding_output = (bitcoin.TYPE_ADDRESS, funding_address, funding_satoshis)
         funding_tx = wallet.mktx([funding_output], None, config, 1000)
         funding_index = funding_tx.outputs().index(funding_output)
-        # commitment tx input
-        c_inputs = [{
-            'type': 'p2wsh',
-            'x_pubkeys': pubkeys,
-            'signatures':[None, None],
-            'num_sig': 2,
-            'prevout_n': funding_index,
-            'prevout_hash': funding_tx.txid(),
-            'value': funding_satoshis,
-            'coinbase': False
-        }]
-        # commitment tx outputs
-        local_script = bytes([opcodes.OP_IF]) + revocation_pubkey + bytes([opcodes.OP_ELSE, opcodes.OP_CSV, opcodes.OP_DROP]) + delayed_pubkey + bytes([opcodes.OP_ENDIF, opcodes.OP_CHECKSIG])
-        local_address = bitcoin.redeem_script_to_address('p2wsh', bh2u(local_script))
-        local_amount = funding_satoshis
-        remote_address = bitcoin.pubkey_to_address('p2wpkh', bh2u(remote_pubkey))
-        remote_amount = 0
-        to_local = (bitcoin.TYPE_ADDRESS, local_address, local_amount)
-        to_remote = (bitcoin.TYPE_ADDRESS, remote_address, remote_amount)
-        # no htlc for the moment
-        c_outputs = [to_local, to_remote]
-        # create commitment tx
-        c_tx = Transaction.from_io(c_inputs, c_outputs)
+        remote_payment_pubkey = accept_channel['payment_basepoint']
+        c_tx = make_commitment(funding_pubkey, remote_pubkey, payment_pubkey, remote_payment_pubkey, revocation_pubkey, delayed_pubkey, funding_tx.txid(), funding_index, funding_satoshis)
         c_tx.sign({bh2u(funding_pubkey): (funding_privkey, True)})
-        # 
-        self.print_error('ctx inputs', c_tx.inputs())
+
         sig_index = pubkeys.index(bh2u(funding_pubkey))
         sig = bytes.fromhex(c_tx.inputs()[0]["signatures"][sig_index])
         self.print_error('sig', len(sig))

lib/tests/test_lnbase.py

@@ -0,0 +1,49 @@
+import unittest
+from lib.util import bh2u
+from lib.lnbase import make_commitment, get_locktime
+
+class Test_LNBase(unittest.TestCase):
+
+    def test_commitment_tx(self):
+
+        funding_tx_id = '8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be'
+        funding_output_index = 0
+        funding_amount_satoshi = 10000000
+        commitment_number = 42
+        local_delay = 144
+        local_dust_limit_satoshi = 546
+
+        local_payment_basepoint = bytes.fromhex('034f355bdcb7cc0af728ef3cceb9615d90684bb5b2ca5f859ab0f0b704075871aa')
+        remote_payment_basepoint = bytes.fromhex('032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991')
+        locktime = get_locktime(42, local_payment_basepoint, remote_payment_basepoint)
+
+        local_funding_privkey = bytes.fromhex('30ff4956bbdd3222d44cc5e8a1261dab1e07957bdac5ae88fe3261ef321f374901')
+        local_funding_pubkey = bytes.fromhex('023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb')
+        remote_funding_pubkey = bytes.fromhex('030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c1')
+        local_privkey = bytes.fromhex('bb13b121cdc357cd2e608b0aea294afca36e2b34cf958e2e6451a2f27469449101')
+        localpubkey = bytes.fromhex('030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e7')
+        remotepubkey = bytes.fromhex('0394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b')
+        local_delayedpubkey = bytes.fromhex('03fd5960528dc152014952efdb702a88f71e3c1653b2314431701ec77e57fde83c')
+        local_revocation_pubkey = bytes.fromhex('0212a140cd0c6539d07cd08dfe09984dec3251ea808b892efeac3ede9402bf2b19')
+        # funding wscript = 5221023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb21030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c152ae
+
+        #name: simple commitment tx with no HTLCs
+        to_local_msat = 7000000000
+        to_remote_msat = 3000000000
+        local_feerate_per_kw = 15000
+        # base commitment transaction fee = 10860
+        # actual commitment transaction fee = 10860
+        # to_local amount 6989140 wscript 63210212a140cd0c6539d07cd08dfe09984dec3251ea808b892efeac3ede9402bf2b1967029000b2752103fd5960528dc152014952efdb702a88f71e3c1653b2314431701ec77e57fde83c68ac
+        # to_remote amount 3000000 P2WPKH(0394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b)
+        #remote_signature = 3045022100f51d2e566a70ba740fc5d8c0f07b9b93d2ed741c3c0860c613173de7d39e7968022041376d520e9c0e1ad52248ddf4b22e12be8763007df977253ef45a4ca3bdb7c0
+        # local_signature = 3044022051b75c73198c6deee1a875871c3961832909acd297c6b908d59e3319e5185a46022055c419379c5051a78d00dbbce11b5b664a0c22815fbcc6fcef6b1937c3836939
+        #num_htlcs: 0
+        c_tx = make_commitment(
+            local_funding_pubkey, remote_funding_pubkey,
+            local_payment_basepoint, remote_payment_basepoint,
+            local_revocation_pubkey, local_delayedpubkey,
+            funding_tx_id, funding_output_index, funding_amount_satoshi)
+        
+        commit_tx = '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'
+        self.assertEqual(str(c_tx), commit_tx)
+