lnbase: more work on make_htlc_tx

lib/lnbase.py

@@ -279,42 +279,51 @@ def overall_weight(num_htlc):
 HTLC_TIMEOUT_WEIGHT = 663
 HTLC_SUCCESS_WEIGHT = 703
 
-def make_htlc_tx(cltv_timeout, htlc_output_txid, htlc_output_index, remotehtlcsig, localhtlcsig, payment_preimage, amount_msat, local_feerate, revocationpubkey, local_delayedpubkey):
-    assert type(cltv_timeout) is int
+def make_htlc_tx_output(amount_msat, local_feerate, revocationpubkey, local_delayedpubkey, success):
+    assert type(amount_msat) is int
+    assert type(local_feerate) is int
+    assert type(revocationpubkey) is bytes
+    assert type(local_delayedpubkey) is bytes
+    script = bytes([opcodes.OP_IF]) \
+        + bfh(push_script(bh2u(revocationpubkey))) \
+        + bytes([opcodes.OP_ELSE]) \
+        + bitcoin.add_number_to_script(144) \
+        + bytes([opcodes.OP_CSV, opcodes.OP_DROP]) \
+        + bfh(push_script(bh2u(local_delayedpubkey))) \
+        + bytes([opcodes.OP_ENDIF, opcodes.OP_CHECKSIG])
+
+    p2wsh = bitcoin.redeem_script_to_address('p2wsh', bh2u(script))
+    weight = HTLC_SUCCESS_WEIGHT if success else HTLC_TIMEOUT_WEIGHT
+    fee = local_feerate * weight
+    output = (bitcoin.TYPE_ADDRESS, p2wsh, amount_msat // 1000 - fee)
+    return output
+
+def make_htlc_tx_inputs(htlc_output_txid, htlc_output_index, remotehtlcsig, localhtlcsig, payment_preimage, revocationpubkey, local_delayedpubkey, amount_msat):
     assert type(htlc_output_txid) is str
     assert type(htlc_output_index) is int
     assert type(remotehtlcsig) is bytes
     assert type(localhtlcsig) is bytes
     assert type(payment_preimage) is bytes
-    assert type(amount_msat) is int
-    assert type(local_feerate) is int
     assert type(revocationpubkey) is bytes
     assert type(local_delayedpubkey) is bytes
+    assert type(amount_msat) is int
     c_inputs = [{
         'type': 'p2wsh',
         'x_pubkeys': [bh2u(x) for x in [revocationpubkey, local_delayedpubkey]],
         'signatures': [bh2u(x) for x in [remotehtlcsig, localhtlcsig, payment_preimage]],
-        'num_sig': 2,
+        'num_sig': 3,
         'prevout_n': htlc_output_index,
         'prevout_hash': htlc_output_txid,
         'value': amount_msat // 1000,
         'coinbase': False,
         'sequence': 0x0
     }]
-    script = bytes([opcodes.OP_IF]) \
-        + bfh(push_script(bh2u(revocationpubkey))) \
-        + bytes([opcodes.OP_ELSE]) \
-        + bitcoin.add_number_to_script(0) \
-        + bytes([opcodes.OP_CSV, opcodes.OP_DROP]) \
-        + bfh(push_script(bh2u(local_delayedpubkey))) \
-        + bytes([opcodes.OP_ENDIF, opcodes.OP_CHECKSIG])
+    return c_inputs
 
-    p2wsh = bitcoin.redeem_script_to_address('p2wsh', bh2u(script))
-    weight = HTLC_SUCCESS_WEIGHT if cltv_timeout == 0 else HTLC_TIMEOUT_WEIGHT
-    fee = local_feerate * weight
-    output = (bitcoin.TYPE_ADDRESS, p2wsh, amount_msat // 1000 - fee)
+def make_htlc_tx(cltv_timeout, inputs, output):
+    assert type(cltv_timeout) is int
     c_outputs = [output]
-    tx = Transaction.from_io(c_inputs, c_outputs, locktime=cltv_timeout, version=2)
+    tx = Transaction.from_io(inputs, c_outputs, locktime=cltv_timeout, version=2)
     tx.BIP_LI01_sort()
     return tx