swapserver: remove config option LIGHTNING_SWAP_HTLC_FIRST; read it from get_pairs instead.

electrum/plugins/swapserver/server.py

@@ -51,6 +51,7 @@ class SwapServer(Logger, EventListener):
         pairs = {
             "info": [],
             "warnings": [],
+            "htlcFirst": True,
             "pairs": {
                 "BTC/BTC": {
                     "rate": 1,

electrum/simple_config.py

@@ -890,7 +890,6 @@ class SimpleConfig(Logger):
     LIGHTNING_USE_GOSSIP = ConfigVar('use_gossip', default=False, type_=bool)
     LIGHTNING_USE_RECOVERABLE_CHANNELS = ConfigVar('use_recoverable_channels', default=True, type_=bool)
     LIGHTNING_ALLOW_INSTANT_SWAPS = ConfigVar('allow_instant_swaps', default=False, type_=bool)
-    LIGHTNING_SWAP_HTLC_FIRST = ConfigVar('swap_htlc_first', default=False, type_=bool)
     LIGHTNING_TO_SELF_DELAY_CSV = ConfigVar('lightning_to_self_delay', default=7 * 144, type_=int)
     LIGHTNING_MAX_FUNDING_SAT = ConfigVar('lightning_max_funding_sat', default=LN_MAX_FUNDING_SAT_LEGACY, type_=int)
 

electrum/submarine_swaps.py

@@ -181,6 +181,7 @@ class SwapManager(Logger):
         self.percentage = 0
         self._min_amount = None
         self._max_amount = None
+        self.server_supports_htlc_first = False
         self.wallet = wallet
         self.lnworker = lnworker
 
@@ -531,7 +532,7 @@ class SwapManager(Logger):
         refund_privkey = os.urandom(32)
         refund_pubkey = ECPrivkey(refund_privkey).get_public_key_bytes(compressed=True)
 
-        if self.wallet.config.LIGHTNING_SWAP_HTLC_FIRST:
+        if self.server_supports_htlc_first:
             self.logger.info('requesting preimage hash for swap')
             request_data = {
                 "invoiceAmount": lightning_amount_sat,
@@ -580,7 +581,7 @@ class SwapManager(Logger):
         lockup_address = data["address"]
         redeem_script = data["redeemScript"]
         # verify redeem_script is built with our pubkey and preimage
-        if self.wallet.config.LIGHTNING_SWAP_HTLC_FIRST:
+        if self.server_supports_htlc_first:
             claim_pubkey, _ = check_reverse_redeem_script(redeem_script, lockup_address, payment_hash, locktime, refund_pubkey=refund_pubkey)
         else:
             claim_pubkey, _ = check_normal_redeem_script(redeem_script, lockup_address, payment_hash, locktime, refund_pubkey=refund_pubkey)
@@ -605,7 +606,7 @@ class SwapManager(Logger):
             prepay=False)
 
         tx = self.create_funding_tx(swap, tx, password)
-        if self.wallet.config.LIGHTNING_SWAP_HTLC_FIRST:
+        if self.server_supports_htlc_first:
             # send invoice to server and wait for htlcs
             request_data = {
                 "preimageHash": payment_hash.hex(),
@@ -780,6 +781,7 @@ class SwapManager(Logger):
         limits = pairs['pairs']['BTC/BTC']['limits']
         self._min_amount = limits['minimal']
         self._max_amount = limits['maximal']
+        self.server_supports_htlc_first = pairs.get('htlcFirst', False)
 
     def pairs_filename(self):
         return os.path.join(self.wallet.config.path, 'swap_pairs')