test: add dust relay output value test

test/functional/test_runner.py

@@ -113,6 +113,7 @@
     'wallet_elements_regression_1172.py --legacy-wallet',
     'wallet_elements_regression_1259.py --legacy-wallet',
     'wallet_elements_21million.py',
+    'wallet_elements_dust_relay.py',
     'feature_trim_headers.py',
     # Longest test should go first, to favor running tests in parallel
     'wallet_hd.py --legacy-wallet',

test/functional/wallet_elements_dust_relay.py

@@ -0,0 +1,123 @@
+#!/usr/bin/env python3
+# Copyright (c) 2017-2020 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+from decimal import Decimal
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import (
+    assert_equal,
+    assert_raises_rpc_error,
+)
+
+class WalletTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.setup_clean_chain = False
+        self.num_nodes = 2
+        args = [
+            "-blindedaddresses=1",
+            "-minrelaytxfee=0.00000100",
+        ]
+        self.extra_args = [
+            args,
+            args + ["-dustrelayfee=0.00003000"], # second node uses default upstream dustrelayfee
+        ]
+
+    def skip_test_if_missing_module(self):
+        self.skip_if_no_wallet()
+
+    def select_unblinded_utxo(self, node):
+        for utxo in node.listunspent():
+            if utxo["amountblinder"] == "00" * 32:
+                return utxo
+            else:
+                continue
+        raise Exception("no unblinded utxo")
+
+    def run_test(self):
+        assert_equal(self.nodes[0].getbalance(), {'bitcoin': 1250})
+        assert_equal(self.nodes[1].getbalance(), {'bitcoin': 1250})
+
+        addr = self.nodes[0].getnewaddress()
+
+        # test dust threshold for upstream dustrelayfee=3sat/vb
+        # 495 sats should succeed for blinded output value
+        amt = "0.00000495"
+        self.nodes[1].sendtoaddress(address=addr, amount=amt)
+        self.generate(self.nodes[1], 1, sync_fun=self.no_op)
+
+        # 494 sats should fail for blinded output value
+        amt = "0.00000494"
+        assert_raises_rpc_error(-6, "Transaction amount too small", self.nodes[1].sendtoaddress, address=addr, amount=amt)
+
+        addr = self.nodes[1].getnewaddress()
+
+        # test dust threshold for elements default dustrelayfee=0.1sat/vb
+        # 17 sats should succeed for blinded output value
+        amt = "0.00000017"
+        self.nodes[0].sendtoaddress(address=addr, amount=amt)
+        self.generate(self.nodes[0], 1, sync_fun=self.no_op)
+
+        # 16 sats should fail for blinded output value
+        amt = "0.00000016"
+        assert_raises_rpc_error(-6, "Transaction amount too small", self.nodes[0].sendtoaddress, address=addr, amount=amt)
+
+        # a blinded transaction created manually can have an output value as low as 1 sat
+        addr = self.nodes[1].getnewaddress()
+        changeaddr = self.nodes[0].getnewaddress()
+        utxo = self.nodes[0].listunspent()[0]
+        amt = Decimal("0.00000001")
+        fee = Decimal("0.00000258")
+        change = utxo["amount"] - amt - fee
+        inputs = [{"txid": utxo["txid"], "vout": utxo["vout"]}]
+        outputs = [{addr: amt}, {changeaddr: change}, {"fee": fee}]
+        raw = self.nodes[0].createrawtransaction(inputs, outputs)
+        blinded = self.nodes[0].blindrawtransaction(raw)
+        signed = self.nodes[0].signrawtransactionwithwallet(blinded)
+        assert signed["complete"]
+        tx = signed["hex"]
+        assert self.nodes[1].testmempoolaccept([tx])[0]["allowed"]
+        assert self.nodes[0].testmempoolaccept([tx])[0]["allowed"]
+        assert_equal(self.nodes[1].sendrawtransaction(tx), self.nodes[0].sendrawtransaction(tx))
+        self.generate(self.nodes[0], 1, sync_fun=self.no_op)
+
+        # explicit transactions have slightly smaller outputs
+        # node 0 will accept an output value of 14 sats but node 1 will not
+        addr = self.nodes[1].getnewaddress(address_type="bech32")
+        changeaddr = self.nodes[0].getnewaddress(address_type="bech32")
+        utxo = self.select_unblinded_utxo(self.nodes[0])
+        amt = Decimal("0.00000014")
+        fee = Decimal("0.00000258")
+        change = utxo["amount"] - amt - fee
+        inputs = [{"txid": utxo["txid"], "vout": utxo["vout"]}]
+        outputs = [{addr: amt}, {changeaddr: change}, {"fee": fee}]
+        raw = self.nodes[0].createrawtransaction(inputs, outputs)
+        signed = self.nodes[0].signrawtransactionwithwallet(raw)
+        assert signed["complete"]
+        tx = signed["hex"]
+        assert self.nodes[0].testmempoolaccept([tx])[0]["allowed"]
+        assert not self.nodes[1].testmempoolaccept([tx])[0]["allowed"]
+        self.nodes[0].sendrawtransaction(tx)
+        assert_raises_rpc_error(-26, "dust", self.nodes[1].sendrawtransaction, tx)
+        self.generate(self.nodes[0], 1, sync_fun=self.no_op)
+
+        # neither node will accept an explicit output value of 13 sats
+        addr = self.nodes[1].getnewaddress(address_type="bech32")
+        changeaddr = self.nodes[0].getnewaddress(address_type="bech32")
+        utxo = self.select_unblinded_utxo(self.nodes[0])
+        amt = Decimal("0.00000013")
+        fee = Decimal("0.00000258")
+        change = utxo["amount"] - amt - fee
+        inputs = [{"txid": utxo["txid"], "vout": utxo["vout"]}]
+        outputs = [{addr: amt}, {changeaddr: change}, {"fee": fee}]
+        raw = self.nodes[0].createrawtransaction(inputs, outputs)
+        signed = self.nodes[0].signrawtransactionwithwallet(raw)
+        assert signed["complete"]
+        tx = signed["hex"]
+        assert not self.nodes[0].testmempoolaccept([tx])[0]["allowed"]
+        assert not self.nodes[1].testmempoolaccept([tx])[0]["allowed"]
+        assert_raises_rpc_error(-26, "dust", self.nodes[0].sendrawtransaction, tx)
+        assert_raises_rpc_error(-26, "dust", self.nodes[1].sendrawtransaction, tx)
+
+if __name__ == '__main__':
+    WalletTest().main()