URI: 
       tsubmarine swaps: create refund transaction - electrum - Electrum Bitcoin wallet
  HTML git clone https://git.parazyd.org/electrum
   DIR Log
   DIR Files
   DIR Refs
   DIR Submodules
       ---
   DIR commit 1b1c7d1f9e836acef8b8ee3db53cde12deacc756
   DIR parent 756dd8eb6669af37fad90f83475b414be15a6829
  HTML Author: ThomasV <thomasv@electrum.org>
       Date:   Fri, 22 May 2020 10:39:30 +0200
       
       submarine swaps: create refund transaction
       
       Diffstat:
         M electrum/commands.py                |      20 ++++++++++++--------
         M electrum/submarine_swaps.py         |      89 +++++++++++++++++++++----------
       
       2 files changed, 73 insertions(+), 36 deletions(-)
       ---
   DIR diff --git a/electrum/commands.py b/electrum/commands.py
       t@@ -60,6 +60,7 @@ from .plugin import run_hook
        from .version import ELECTRUM_VERSION
        from .simple_config import SimpleConfig
        from .invoices import LNInvoice
       +from . import submarine_swaps
        
        
        if TYPE_CHECKING:
       t@@ -1102,20 +1103,23 @@ class Commands:
        
            @command('wnp')
            async def submarine_swap(self, amount, password=None, wallet: Abstract_Wallet = None):
       -        from .submarine_swaps import submarine_swap
       -        amount_sat = satoshis(amount)
       -        return await submarine_swap(amount_sat, wallet, self.network, password)
       +        return await submarine_swaps.normal_swap(satoshis(amount), wallet, self.network, password)
        
            @command('wn')
            async def reverse_swap(self, amount, wallet: Abstract_Wallet = None):
       -        from .submarine_swaps import reverse_swap
       -        amount_sat = satoshis(amount)
       -        return await reverse_swap(amount_sat, wallet, self.network)
       +        return await submarine_swaps.reverse_swap(satoshis(amount), wallet, self.network)
       +
       +    @command('n')
       +    async def get_pairs(self):
       +        return await submarine_swaps.get_pairs(self.network)
        
            @command('wn')
            async def claim_swap(self, key, wallet: Abstract_Wallet = None):
       -        from .submarine_swaps import claim_swap
       -        return await claim_swap(key, wallet)
       +        return await submarine_swaps.claim_swap(key, wallet)
       +
       +    @command('wn')
       +    async def refund_swap(self, key, wallet: Abstract_Wallet = None):
       +        return await submarine_swaps.refund_swap(key, wallet)
        
        def eval_bool(x: str) -> bool:
            if x == 'false': return False
   DIR diff --git a/electrum/submarine_swaps.py b/electrum/submarine_swaps.py
       t@@ -3,11 +3,12 @@ import json
        import os
        from .crypto import sha256, hash_160
        from .ecc import ECPrivkey
       -from .bitcoin import address_to_script, script_to_p2wsh, redeem_script_to_address, opcodes
       +from .bitcoin import address_to_script, script_to_p2wsh, redeem_script_to_address, opcodes, p2wsh_nested_script
        from .transaction import TxOutpoint, PartialTxInput, PartialTxOutput, PartialTransaction, construct_witness
        from .transaction import script_GetOp, match_script_against_template, OPPushDataGeneric, OPPushDataPubkey
        from .transaction import Transaction
        from .util import log_exceptions
       +from .bitcoin import dust_threshold
        
        
        API_URL = 'http://ecdsa.org:9001'
       t@@ -49,32 +50,44 @@ WITNESS_TEMPLATE_REVERSE_SWAP = [
        ]
        
        
       -def create_claim_tx(txin, witness_script, preimage, privkey:bytes, amount_sat, address, fee):
       +def create_claim_tx(txin, witness_script, preimage, privkey:bytes, address, amount_sat, is_refund):
            pubkey = ECPrivkey(privkey).get_public_key_bytes(compressed=True)
       -    txin.script_type = 'p2wsh'
       +    print(txin.to_json())
       +    if is_refund:
       +        txin.script_type = 'p2wsh-p2sh'
       +        txin.redeem_script = bytes.fromhex(p2wsh_nested_script(witness_script.hex()))
       +    else:
       +        txin.script_type = 'p2wsh'
            txin.script_sig = b''
            txin.pubkeys = [pubkey]
            txin.num_sig = 1
            txin.witness_script = witness_script
       -    txin._trusted_value_sats = amount_sat
       -    txout = PartialTxOutput(scriptpubkey=bytes.fromhex(address_to_script(address)), value=amount_sat - fee)
       +    txout = PartialTxOutput(scriptpubkey=bytes.fromhex(address_to_script(address)), value=amount_sat)
            tx = PartialTransaction.from_io([txin], [txout], version=2)
            sig = bytes.fromhex(tx.sign_txin(0, privkey))
       -    witness = construct_witness([sig, preimage, witness_script])
       -    tx.inputs()[0].witness = bytes.fromhex(witness)
       +    witness = [sig, witness_script] if is_refund else [sig, preimage, witness_script]
       +    tx.inputs()[0].witness = bytes.fromhex(construct_witness(witness))
            assert tx.is_complete()
            return tx
        
        
        @log_exceptions
       -async def _claim_swap(lnworker, lockup_address, redeem_script, preimage, privkey, onchain_amount, address):
       -    # add address to lnwatcher
       +async def _claim_swap(lnworker, lockup_address, redeem_script, preimage, privkey, address, locktime, is_refund=False):
            lnwatcher = lnworker.lnwatcher
            utxos = lnwatcher.get_addr_utxo(lockup_address)
       +    delta = lnwatcher.network.get_local_height() - locktime
            for txin in list(utxos.values()):
                fee = lnwatcher.config.estimate_fee(136, allow_fallback_to_static_rates=True)
       -        tx = create_claim_tx(txin, redeem_script, preimage, privkey, onchain_amount, address, fee)
       -        await lnwatcher.network.broadcast_transaction(tx)
       +        amount_sat = txin._trusted_value_sats - fee
       +        if amount_sat < dust_threshold():
       +            print('dust')
       +            continue
       +        tx = create_claim_tx(txin, redeem_script, preimage, privkey, address, amount_sat, is_refund)
       +        if is_refund and delta < 0:
       +            print('height not reached for refund', delta, locktime)
       +            print(tx.serialize())
       +        else:
       +            await lnwatcher.network.broadcast_transaction(tx)
        
        
        @log_exceptions
       t@@ -85,17 +98,33 @@ async def claim_swap(key, wallet):
            data = swaps[key]
            onchain_amount = data['onchainAmount']
            redeem_script = bytes.fromhex(data['redeemScript'])
       +    locktime = data['timeoutBlockHeight']
            lockup_address = data['lockupAddress']
            preimage = bytes.fromhex(data['preimage'])
            privkey = bytes.fromhex(data['privkey'])
       -    callback = lambda: _claim_swap(lnworker, lockup_address, redeem_script, preimage, privkey, onchain_amount, address)
       +    callback = lambda: _claim_swap(lnworker, lockup_address, redeem_script, preimage, privkey, address, locktime, is_refund=False)
            lnworker.lnwatcher.add_callback(lockup_address, callback)
            return True
        
        
        @log_exceptions
       -async def submarine_swap(amount_sat, wallet: 'Abstract_Wallet', network: 'Network', password):
       -    # 
       +async def refund_swap(key, wallet):
       +    lnworker = wallet.lnworker
       +    address = wallet.get_unused_address()
       +    swaps = wallet.db.get_dict('submarine_swaps')
       +    data = swaps[key]
       +    lockup_address = data['address']
       +    redeem_script = bytes.fromhex(data['redeemScript'])
       +    locktime = data['timeoutBlockHeight']
       +    preimage = bytes.fromhex(data['preimage'])
       +    privkey = bytes.fromhex(data['privkey'])
       +    callback = lambda: _claim_swap(lnworker, lockup_address, redeem_script, preimage, privkey, address, locktime, is_refund=True)
       +    lnworker.lnwatcher.add_callback(lockup_address, callback)
       +    return True
       +
       +
       +@log_exceptions
       +async def normal_swap(amount_sat, wallet: 'Abstract_Wallet', network: 'Network', password):
            lnworker = wallet.lnworker
            privkey = os.urandom(32)
            pubkey = ECPrivkey(privkey).get_public_key_bytes(compressed=True)
       t@@ -124,8 +153,6 @@ async def submarine_swap(amount_sat, wallet: 'Abstract_Wallet', network: 'Networ
            locktime = data["timeoutBlockHeight"],
            lockup_address = data["address"]
            redeem_script = data["redeemScript"]
       -    
       -    print(data)
            # verify redeem_script is built with our pubkey and preimage
            redeem_script = bytes.fromhex(redeem_script)
            parsed_script = [x for x in script_GetOp(redeem_script)]
       t@@ -135,19 +162,15 @@ async def submarine_swap(amount_sat, wallet: 'Abstract_Wallet', network: 'Networ
            assert hash_160(preimage) == parsed_script[1][1]
            assert pubkey == parsed_script[9][1]
            # verify that we will have enought time to get our tx confirmed
       -    cltv = int.from_bytes(parsed_script[6][1], byteorder='little')
       -    assert cltv - network.get_local_height() == 140
       -
       +    assert locktime == int.from_bytes(parsed_script[6][1], byteorder='little')
       +    assert locktime - network.get_local_height() == 140
            # save swap data in wallet in case we need a refund
            data['privkey'] = privkey.hex()
            data['preimage'] = preimage.hex()
            swaps = wallet.db.get_dict('submarine_swaps')
            swaps[response_id] = data
       -    # todo: add callback to lnwatcher (with cltv)
       -    #callback = lambda: _claim_refund(lnworker, lockup_address, redeem_script, preimage, privkey, onchain_amount, address)
       -    #lnworker.lnwatcher.add_callback(lockup_address, callback)
       -
       -    # pay onchain. must not be RBF
       +    callback = lambda: _claim_swap(lnworker, lockup_address, redeem_script, preimage, privkey, address, locktime, is_refund=True)
       +    lnworker.lnwatcher.add_callback(lockup_address, callback)
            outputs = [PartialTxOutput.from_address_and_value(lockup_address, onchain_amount)]
            tx = wallet.create_transaction(outputs=outputs, rbf=False, password=password)
            await network.broadcast_transaction(tx)
       t@@ -183,7 +206,7 @@ async def reverse_swap(amount_sat, wallet: 'Abstract_Wallet', network: 'Network'
            invoice = data['invoice']
            lockup_address = data['lockupAddress']
            redeem_script = data['redeemScript']
       -    timeout_block_height = data['timeoutBlockHeight']
       +    locktime = data['timeoutBlockHeight']
            onchain_amount = data["onchainAmount"]
            response_id = data['id']
            # verify redeem_script is built with our pubkey and preimage
       t@@ -194,8 +217,8 @@ async def reverse_swap(amount_sat, wallet: 'Abstract_Wallet', network: 'Network'
            assert hash_160(preimage) == parsed_script[5][1]
            assert pubkey == parsed_script[7][1]
            # verify that we will have enought time to get our tx confirmed
       -    cltv = int.from_bytes(parsed_script[10][1], byteorder='little')
       -    assert cltv - network.get_local_height() > 10
       +    assert locktime == int.from_bytes(parsed_script[10][1], byteorder='little')
       +    assert locktime - network.get_local_height() > 10
            # verify invoice preimage_hash
            lnworker = wallet.lnworker
            lnaddr = lnworker._check_invoice(invoice, amount_sat)
       t@@ -207,7 +230,7 @@ async def reverse_swap(amount_sat, wallet: 'Abstract_Wallet', network: 'Network'
            swaps = wallet.db.get_dict('submarine_swaps')
            swaps[response_id] = data
            # add callback to lnwatcher
       -    callback = lambda: _claim_swap(lnworker, lockup_address, redeem_script, preimage, privkey, onchain_amount, address)
       +    callback = lambda: _claim_swap(lnworker, lockup_address, redeem_script, preimage, privkey, address, locktime, is_refund=False)
            lnworker.lnwatcher.add_callback(lockup_address, callback)
            # initiate payment.
            success, log = await lnworker._pay(invoice, attempts=5)
       t@@ -218,3 +241,13 @@ async def reverse_swap(amount_sat, wallet: 'Abstract_Wallet', network: 'Network'
                'id':response_id,
                'success':success,
            }
       +
       +
       +@log_exceptions
       +async def get_pairs(network):
       +    response = await network._send_http_on_proxy(
       +        'get',
       +        API_URL + '/getpairs',
       +        timeout=30)
       +    data = json.loads(response)
       +    return data