aboutsummaryrefslogtreecommitdiff
path: root/test/functional/p2p-segwit.py
blob: 5f7cc05413d01cce442ce7fa6c924dd2c68f4631 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
#!/usr/bin/env python3
# Copyright (c) 2016-2017 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
"""Test segwit transactions and blocks on P2P network."""

from test_framework.mininode import *
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import *
from test_framework.script import *
from test_framework.blocktools import create_block, create_coinbase, add_witness_commitment, get_witness_script, WITNESS_COMMITMENT_HEADER
from test_framework.key import CECKey, CPubKey
import time
import random
from binascii import hexlify

# The versionbit bit used to signal activation of SegWit
VB_WITNESS_BIT = 1
VB_PERIOD = 144
VB_TOP_BITS = 0x20000000

MAX_SIGOP_COST = 80000


# Calculate the virtual size of a witness block:
# (base + witness/4)
def get_virtual_size(witness_block):
    base_size = len(witness_block.serialize(with_witness=False))
    total_size = len(witness_block.serialize(with_witness=True))
    # the "+3" is so we round up
    vsize = int((3*base_size + total_size + 3)/4)
    return vsize

def test_transaction_acceptance(rpc, p2p, tx, with_witness, accepted, reason=None):
    """Send a transaction to the node and check that it's accepted to the mempool

    - Submit the transaction over the p2p interface
    - use the getrawmempool rpc to check for acceptance."""
    tx_message = msg_tx(tx)
    if with_witness:
        tx_message = msg_witness_tx(tx)
    p2p.send_message(tx_message)
    p2p.sync_with_ping()
    assert_equal(tx.hash in rpc.getrawmempool(), accepted)
    if (reason != None and not accepted):
        # Check the rejection reason as well.
        with mininode_lock:
            assert_equal(p2p.last_message["reject"].reason, reason)

def test_witness_block(rpc, p2p, block, accepted, with_witness=True):
    """Send a block to the node and check that it's accepted

    - Submit the block over the p2p interface
    - use the getbestblockhash rpc to check for acceptance."""
    if with_witness:
        p2p.send_message(msg_witness_block(block))
    else:
        p2p.send_message(msg_block(block))
    p2p.sync_with_ping()
    assert_equal(rpc.getbestblockhash() == block.hash, accepted)

class TestNode(P2PInterface):
    def __init__(self):
        super().__init__()
        self.getdataset = set()

    def on_getdata(self, message):
        for inv in message.inv:
            self.getdataset.add(inv.hash)

    def announce_tx_and_wait_for_getdata(self, tx, timeout=60):
        with mininode_lock:
            self.last_message.pop("getdata", None)
        self.send_message(msg_inv(inv=[CInv(1, tx.sha256)]))
        self.wait_for_getdata(timeout)

    def announce_block_and_wait_for_getdata(self, block, use_header, timeout=60):
        with mininode_lock:
            self.last_message.pop("getdata", None)
            self.last_message.pop("getheaders", None)
        msg = msg_headers()
        msg.headers = [ CBlockHeader(block) ]
        if use_header:
            self.send_message(msg)
        else:
            self.send_message(msg_inv(inv=[CInv(2, block.sha256)]))
            self.wait_for_getheaders()
            self.send_message(msg)
        self.wait_for_getdata()

    def request_block(self, blockhash, inv_type, timeout=60):
        with mininode_lock:
            self.last_message.pop("block", None)
        self.send_message(msg_getdata(inv=[CInv(inv_type, blockhash)]))
        self.wait_for_block(blockhash, timeout)
        return self.last_message["block"].block

# Used to keep track of anyone-can-spend outputs that we can use in the tests
class UTXO():
    def __init__(self, sha256, n, nValue):
        self.sha256 = sha256
        self.n = n
        self.nValue = nValue

# Helper for getting the script associated with a P2PKH
def GetP2PKHScript(pubkeyhash):
    return CScript([CScriptOp(OP_DUP), CScriptOp(OP_HASH160), pubkeyhash, CScriptOp(OP_EQUALVERIFY), CScriptOp(OP_CHECKSIG)])

# Add signature for a P2PK witness program.
def sign_P2PK_witness_input(script, txTo, inIdx, hashtype, value, key):
    tx_hash = SegwitVersion1SignatureHash(script, txTo, inIdx, hashtype, value)
    signature = key.sign(tx_hash) + chr(hashtype).encode('latin-1')
    txTo.wit.vtxinwit[inIdx].scriptWitness.stack = [signature, script]
    txTo.rehash()


class SegWitTest(BitcoinTestFramework):
    def set_test_params(self):
        self.setup_clean_chain = True
        self.num_nodes = 3
        # This test tests SegWit both pre and post-activation, so use the normal BIP9 activation.
        self.extra_args = [["-whitelist=127.0.0.1", "-vbparams=segwit:0:999999999999"], ["-whitelist=127.0.0.1", "-acceptnonstdtxn=0", "-vbparams=segwit:0:999999999999"], ["-whitelist=127.0.0.1", "-vbparams=segwit:0:0"]]

    def setup_network(self):
        self.setup_nodes()
        connect_nodes(self.nodes[0], 1)
        connect_nodes(self.nodes[0], 2)
        self.sync_all()

    ''' Helpers '''
    # Build a block on top of node0's tip.
    def build_next_block(self, nVersion=4):
        tip = self.nodes[0].getbestblockhash()
        height = self.nodes[0].getblockcount() + 1
        block_time = self.nodes[0].getblockheader(tip)["mediantime"] + 1
        block = create_block(int(tip, 16), create_coinbase(height), block_time)
        block.nVersion = nVersion
        block.rehash()
        return block

    # Adds list of transactions to block, adds witness commitment, then solves.
    def update_witness_block_with_transactions(self, block, tx_list, nonce=0):
        block.vtx.extend(tx_list)
        add_witness_commitment(block, nonce)
        block.solve()
        return

    ''' Individual tests '''
    def test_witness_services(self):
        self.log.info("Verifying NODE_WITNESS service bit")
        assert((self.test_node.nServices & NODE_WITNESS) != 0)


    # See if sending a regular transaction works, and create a utxo
    # to use in later tests.
    def test_non_witness_transaction(self):
        # Mine a block with an anyone-can-spend coinbase,
        # let it mature, then try to spend it.
        self.log.info("Testing non-witness transaction")
        block = self.build_next_block(nVersion=1)
        block.solve()
        self.test_node.send_message(msg_block(block))
        self.test_node.sync_with_ping() # make sure the block was processed
        txid = block.vtx[0].sha256

        self.nodes[0].generate(99) # let the block mature

        # Create a transaction that spends the coinbase
        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(txid, 0), b""))
        tx.vout.append(CTxOut(49*100000000, CScript([OP_TRUE])))
        tx.calc_sha256()

        # Check that serializing it with or without witness is the same
        # This is a sanity check of our testing framework.
        assert_equal(msg_tx(tx).serialize(), msg_witness_tx(tx).serialize())

        self.test_node.send_message(msg_witness_tx(tx))
        self.test_node.sync_with_ping() # make sure the tx was processed
        assert(tx.hash in self.nodes[0].getrawmempool())
        # Save this transaction for later
        self.utxo.append(UTXO(tx.sha256, 0, 49*100000000))
        self.nodes[0].generate(1)


    # Verify that blocks with witnesses are rejected before activation.
    def test_unnecessary_witness_before_segwit_activation(self):
        self.log.info("Testing behavior of unnecessary witnesses")
        # For now, rely on earlier tests to have created at least one utxo for
        # us to use
        assert(len(self.utxo) > 0)
        assert(get_bip9_status(self.nodes[0], 'segwit')['status'] != 'active')

        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))
        tx.vout.append(CTxOut(self.utxo[0].nValue-1000, CScript([OP_TRUE])))
        tx.wit.vtxinwit.append(CTxInWitness())
        tx.wit.vtxinwit[0].scriptWitness.stack = [CScript([CScriptNum(1)])]

        # Verify the hash with witness differs from the txid
        # (otherwise our testing framework must be broken!)
        tx.rehash()
        assert(tx.sha256 != tx.calc_sha256(with_witness=True))

        # Construct a segwit-signaling block that includes the transaction.
        block = self.build_next_block(nVersion=(VB_TOP_BITS|(1 << VB_WITNESS_BIT)))
        self.update_witness_block_with_transactions(block, [tx])
        # Sending witness data before activation is not allowed (anti-spam
        # rule).
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)
        # TODO: fix synchronization so we can test reject reason
        # Right now, bitcoind delays sending reject messages for blocks
        # until the future, making synchronization here difficult.
        #assert_equal(self.test_node.last_message["reject"].reason, "unexpected-witness")

        # But it should not be permanently marked bad...
        # Resend without witness information.
        self.test_node.send_message(msg_block(block))
        self.test_node.sync_with_ping()
        assert_equal(self.nodes[0].getbestblockhash(), block.hash)

        sync_blocks(self.nodes)

        # Create a p2sh output -- this is so we can pass the standardness
        # rules (an anyone-can-spend OP_TRUE would be rejected, if not wrapped
        # in P2SH).
        p2sh_program = CScript([OP_TRUE])
        p2sh_pubkey = hash160(p2sh_program)
        scriptPubKey = CScript([OP_HASH160, p2sh_pubkey, OP_EQUAL])

        # Now check that unnecessary witnesses can't be used to blind a node
        # to a transaction, eg by violating standardness checks.
        tx2 = CTransaction()
        tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), b""))
        tx2.vout.append(CTxOut(tx.vout[0].nValue-1000, scriptPubKey))
        tx2.rehash()
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx2, False, True)
        self.nodes[0].generate(1)
        sync_blocks(self.nodes)

        # We'll add an unnecessary witness to this transaction that would cause
        # it to be non-standard, to test that violating policy with a witness before
        # segwit activation doesn't blind a node to a transaction.  Transactions
        # rejected for having a witness before segwit activation shouldn't be added
        # to the rejection cache.
        tx3 = CTransaction()
        tx3.vin.append(CTxIn(COutPoint(tx2.sha256, 0), CScript([p2sh_program])))
        tx3.vout.append(CTxOut(tx2.vout[0].nValue-1000, scriptPubKey))
        tx3.wit.vtxinwit.append(CTxInWitness())
        tx3.wit.vtxinwit[0].scriptWitness.stack = [b'a'*400000]
        tx3.rehash()
        # Note that this should be rejected for the premature witness reason,
        # rather than a policy check, since segwit hasn't activated yet.
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, tx3, True, False, b'no-witness-yet')

        # If we send without witness, it should be accepted.
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, tx3, False, True)

        # Now create a new anyone-can-spend utxo for the next test.
        tx4 = CTransaction()
        tx4.vin.append(CTxIn(COutPoint(tx3.sha256, 0), CScript([p2sh_program])))
        tx4.vout.append(CTxOut(tx3.vout[0].nValue-1000, CScript([OP_TRUE])))
        tx4.rehash()
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx3, False, True)
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx4, False, True)

        self.nodes[0].generate(1)
        sync_blocks(self.nodes)

        # Update our utxo list; we spent the first entry.
        self.utxo.pop(0)
        self.utxo.append(UTXO(tx4.sha256, 0, tx4.vout[0].nValue))


    # Mine enough blocks for segwit's vb state to be 'started'.
    def advance_to_segwit_started(self):
        height = self.nodes[0].getblockcount()
        # Will need to rewrite the tests here if we are past the first period
        assert(height < VB_PERIOD - 1)
        # Genesis block is 'defined'.
        assert_equal(get_bip9_status(self.nodes[0], 'segwit')['status'], 'defined')
        # Advance to end of period, status should now be 'started'
        self.nodes[0].generate(VB_PERIOD-height-1)
        assert_equal(get_bip9_status(self.nodes[0], 'segwit')['status'], 'started')

    # Mine enough blocks to lock in segwit, but don't activate.
    # TODO: we could verify that lockin only happens at the right threshold of
    # signalling blocks, rather than just at the right period boundary.
    def advance_to_segwit_lockin(self):
        height = self.nodes[0].getblockcount()
        assert_equal(get_bip9_status(self.nodes[0], 'segwit')['status'], 'started')
        # Advance to end of period, and verify lock-in happens at the end
        self.nodes[0].generate(VB_PERIOD-1)
        height = self.nodes[0].getblockcount()
        assert((height % VB_PERIOD) == VB_PERIOD - 2)
        assert_equal(get_bip9_status(self.nodes[0], 'segwit')['status'], 'started')
        self.nodes[0].generate(1)
        assert_equal(get_bip9_status(self.nodes[0], 'segwit')['status'], 'locked_in')


    # Mine enough blocks to activate segwit.
    # TODO: we could verify that activation only happens at the right threshold
    # of signalling blocks, rather than just at the right period boundary.
    def advance_to_segwit_active(self):
        assert_equal(get_bip9_status(self.nodes[0], 'segwit')['status'], 'locked_in')
        height = self.nodes[0].getblockcount()
        self.nodes[0].generate(VB_PERIOD - (height%VB_PERIOD) - 2)
        assert_equal(get_bip9_status(self.nodes[0], 'segwit')['status'], 'locked_in')
        self.nodes[0].generate(1)
        assert_equal(get_bip9_status(self.nodes[0], 'segwit')['status'], 'active')


    # This test can only be run after segwit has activated
    def test_witness_commitments(self):
        self.log.info("Testing witness commitments")

        # First try a correct witness commitment.
        block = self.build_next_block()
        add_witness_commitment(block)
        block.solve()

        # Test the test -- witness serialization should be different
        assert(msg_witness_block(block).serialize() != msg_block(block).serialize())

        # This empty block should be valid.
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        # Try to tweak the nonce
        block_2 = self.build_next_block()
        add_witness_commitment(block_2, nonce=28)
        block_2.solve()

        # The commitment should have changed!
        assert(block_2.vtx[0].vout[-1] != block.vtx[0].vout[-1])

        # This should also be valid.
        test_witness_block(self.nodes[0].rpc, self.test_node, block_2, accepted=True)

        # Now test commitments with actual transactions
        assert (len(self.utxo) > 0)
        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))

        # Let's construct a witness program
        witness_program = CScript([OP_TRUE])
        witness_hash = sha256(witness_program)
        scriptPubKey = CScript([OP_0, witness_hash])
        tx.vout.append(CTxOut(self.utxo[0].nValue-1000, scriptPubKey))
        tx.rehash()

        # tx2 will spend tx1, and send back to a regular anyone-can-spend address
        tx2 = CTransaction()
        tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), b""))
        tx2.vout.append(CTxOut(tx.vout[0].nValue-1000, witness_program))
        tx2.wit.vtxinwit.append(CTxInWitness())
        tx2.wit.vtxinwit[0].scriptWitness.stack = [witness_program]
        tx2.rehash()

        block_3 = self.build_next_block()
        self.update_witness_block_with_transactions(block_3, [tx, tx2], nonce=1)
        # Add an extra OP_RETURN output that matches the witness commitment template,
        # even though it has extra data after the incorrect commitment.
        # This block should fail.
        block_3.vtx[0].vout.append(CTxOut(0, CScript([OP_RETURN, WITNESS_COMMITMENT_HEADER + ser_uint256(2), 10])))
        block_3.vtx[0].rehash()
        block_3.hashMerkleRoot = block_3.calc_merkle_root()
        block_3.rehash()
        block_3.solve()

        test_witness_block(self.nodes[0].rpc, self.test_node, block_3, accepted=False)

        # Add a different commitment with different nonce, but in the
        # right location, and with some funds burned(!).
        # This should succeed (nValue shouldn't affect finding the
        # witness commitment).
        add_witness_commitment(block_3, nonce=0)
        block_3.vtx[0].vout[0].nValue -= 1
        block_3.vtx[0].vout[-1].nValue += 1
        block_3.vtx[0].rehash()
        block_3.hashMerkleRoot = block_3.calc_merkle_root()
        block_3.rehash()
        assert(len(block_3.vtx[0].vout) == 4) # 3 OP_returns
        block_3.solve()
        test_witness_block(self.nodes[0].rpc, self.test_node, block_3, accepted=True)

        # Finally test that a block with no witness transactions can
        # omit the commitment.
        block_4 = self.build_next_block()
        tx3 = CTransaction()
        tx3.vin.append(CTxIn(COutPoint(tx2.sha256, 0), b""))
        tx3.vout.append(CTxOut(tx.vout[0].nValue-1000, witness_program))
        tx3.rehash()
        block_4.vtx.append(tx3)
        block_4.hashMerkleRoot = block_4.calc_merkle_root()
        block_4.solve()
        test_witness_block(self.nodes[0].rpc, self.test_node, block_4, with_witness=False, accepted=True)

        # Update available utxo's for use in later test.
        self.utxo.pop(0)
        self.utxo.append(UTXO(tx3.sha256, 0, tx3.vout[0].nValue))


    def test_block_malleability(self):
        self.log.info("Testing witness block malleability")

        # Make sure that a block that has too big a virtual size
        # because of a too-large coinbase witness is not permanently
        # marked bad.
        block = self.build_next_block()
        add_witness_commitment(block)
        block.solve()

        block.vtx[0].wit.vtxinwit[0].scriptWitness.stack.append(b'a'*5000000)
        assert(get_virtual_size(block) > MAX_BLOCK_BASE_SIZE)

        # We can't send over the p2p network, because this is too big to relay
        # TODO: repeat this test with a block that can be relayed
        self.nodes[0].submitblock(bytes_to_hex_str(block.serialize(True)))

        assert(self.nodes[0].getbestblockhash() != block.hash)

        block.vtx[0].wit.vtxinwit[0].scriptWitness.stack.pop()
        assert(get_virtual_size(block) < MAX_BLOCK_BASE_SIZE)
        self.nodes[0].submitblock(bytes_to_hex_str(block.serialize(True)))

        assert(self.nodes[0].getbestblockhash() == block.hash)

        # Now make sure that malleating the witness nonce doesn't
        # result in a block permanently marked bad.
        block = self.build_next_block()
        add_witness_commitment(block)
        block.solve()

        # Change the nonce -- should not cause the block to be permanently
        # failed
        block.vtx[0].wit.vtxinwit[0].scriptWitness.stack = [ ser_uint256(1) ]
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)

        # Changing the witness nonce doesn't change the block hash
        block.vtx[0].wit.vtxinwit[0].scriptWitness.stack = [ ser_uint256(0) ]
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)


    def test_witness_block_size(self):
        self.log.info("Testing witness block size limit")
        # TODO: Test that non-witness carrying blocks can't exceed 1MB
        # Skipping this test for now; this is covered in p2p-fullblocktest.py

        # Test that witness-bearing blocks are limited at ceil(base + wit/4) <= 1MB.
        block = self.build_next_block()

        assert(len(self.utxo) > 0)
        
        # Create a P2WSH transaction.
        # The witness program will be a bunch of OP_2DROP's, followed by OP_TRUE.
        # This should give us plenty of room to tweak the spending tx's
        # virtual size.
        NUM_DROPS = 200 # 201 max ops per script!
        NUM_OUTPUTS = 50

        witness_program = CScript([OP_2DROP]*NUM_DROPS + [OP_TRUE])
        witness_hash = uint256_from_str(sha256(witness_program))
        scriptPubKey = CScript([OP_0, ser_uint256(witness_hash)])

        prevout = COutPoint(self.utxo[0].sha256, self.utxo[0].n)
        value = self.utxo[0].nValue

        parent_tx = CTransaction()
        parent_tx.vin.append(CTxIn(prevout, b""))
        child_value = int(value/NUM_OUTPUTS)
        for i in range(NUM_OUTPUTS):
            parent_tx.vout.append(CTxOut(child_value, scriptPubKey))
        parent_tx.vout[0].nValue -= 50000
        assert(parent_tx.vout[0].nValue > 0)
        parent_tx.rehash()

        child_tx = CTransaction()
        for i in range(NUM_OUTPUTS):
            child_tx.vin.append(CTxIn(COutPoint(parent_tx.sha256, i), b""))
        child_tx.vout = [CTxOut(value - 100000, CScript([OP_TRUE]))]
        for i in range(NUM_OUTPUTS):
            child_tx.wit.vtxinwit.append(CTxInWitness())
            child_tx.wit.vtxinwit[-1].scriptWitness.stack = [b'a'*195]*(2*NUM_DROPS) + [witness_program]
        child_tx.rehash()
        self.update_witness_block_with_transactions(block, [parent_tx, child_tx])

        vsize = get_virtual_size(block)
        additional_bytes = (MAX_BLOCK_BASE_SIZE - vsize)*4
        i = 0
        while additional_bytes > 0:
            # Add some more bytes to each input until we hit MAX_BLOCK_BASE_SIZE+1
            extra_bytes = min(additional_bytes+1, 55)
            block.vtx[-1].wit.vtxinwit[int(i/(2*NUM_DROPS))].scriptWitness.stack[i%(2*NUM_DROPS)] = b'a'*(195+extra_bytes)
            additional_bytes -= extra_bytes
            i += 1

        block.vtx[0].vout.pop()  # Remove old commitment
        add_witness_commitment(block)
        block.solve()
        vsize = get_virtual_size(block)
        assert_equal(vsize, MAX_BLOCK_BASE_SIZE + 1)
        # Make sure that our test case would exceed the old max-network-message
        # limit
        assert(len(block.serialize(True)) > 2*1024*1024)

        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)

        # Now resize the second transaction to make the block fit.
        cur_length = len(block.vtx[-1].wit.vtxinwit[0].scriptWitness.stack[0])
        block.vtx[-1].wit.vtxinwit[0].scriptWitness.stack[0] = b'a'*(cur_length-1)
        block.vtx[0].vout.pop()
        add_witness_commitment(block)
        block.solve()
        assert(get_virtual_size(block) == MAX_BLOCK_BASE_SIZE)

        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        # Update available utxo's
        self.utxo.pop(0)
        self.utxo.append(UTXO(block.vtx[-1].sha256, 0, block.vtx[-1].vout[0].nValue))


    # submitblock will try to add the nonce automatically, so that mining
    # software doesn't need to worry about doing so itself.
    def test_submit_block(self):
        block = self.build_next_block()

        # Try using a custom nonce and then don't supply it.
        # This shouldn't possibly work.
        add_witness_commitment(block, nonce=1)
        block.vtx[0].wit = CTxWitness() # drop the nonce
        block.solve()
        self.nodes[0].submitblock(bytes_to_hex_str(block.serialize(True)))
        assert(self.nodes[0].getbestblockhash() != block.hash)

        # Now redo commitment with the standard nonce, but let bitcoind fill it in.
        add_witness_commitment(block, nonce=0)
        block.vtx[0].wit = CTxWitness()
        block.solve()
        self.nodes[0].submitblock(bytes_to_hex_str(block.serialize(True)))
        assert_equal(self.nodes[0].getbestblockhash(), block.hash)

        # This time, add a tx with non-empty witness, but don't supply
        # the commitment.
        block_2 = self.build_next_block()

        add_witness_commitment(block_2)

        block_2.solve()

        # Drop commitment and nonce -- submitblock should not fill in.
        block_2.vtx[0].vout.pop()
        block_2.vtx[0].wit = CTxWitness()

        self.nodes[0].submitblock(bytes_to_hex_str(block_2.serialize(True)))
        # Tip should not advance!
        assert(self.nodes[0].getbestblockhash() != block_2.hash)


    # Consensus tests of extra witness data in a transaction.
    def test_extra_witness_data(self):
        self.log.info("Testing extra witness data in tx")

        assert(len(self.utxo) > 0)
        
        block = self.build_next_block()

        witness_program = CScript([OP_DROP, OP_TRUE])
        witness_hash = sha256(witness_program)
        scriptPubKey = CScript([OP_0, witness_hash])

        # First try extra witness data on a tx that doesn't require a witness
        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))
        tx.vout.append(CTxOut(self.utxo[0].nValue-2000, scriptPubKey))
        tx.vout.append(CTxOut(1000, CScript([OP_TRUE]))) # non-witness output
        tx.wit.vtxinwit.append(CTxInWitness())
        tx.wit.vtxinwit[0].scriptWitness.stack = [CScript([])]
        tx.rehash()
        self.update_witness_block_with_transactions(block, [tx])

        # Extra witness data should not be allowed.
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)

        # Try extra signature data.  Ok if we're not spending a witness output.
        block.vtx[1].wit.vtxinwit = []
        block.vtx[1].vin[0].scriptSig = CScript([OP_0])
        block.vtx[1].rehash()
        add_witness_commitment(block)
        block.solve()

        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        # Now try extra witness/signature data on an input that DOES require a
        # witness
        tx2 = CTransaction()
        tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), b"")) # witness output
        tx2.vin.append(CTxIn(COutPoint(tx.sha256, 1), b"")) # non-witness
        tx2.vout.append(CTxOut(tx.vout[0].nValue, CScript([OP_TRUE])))
        tx2.wit.vtxinwit.extend([CTxInWitness(), CTxInWitness()])
        tx2.wit.vtxinwit[0].scriptWitness.stack = [ CScript([CScriptNum(1)]), CScript([CScriptNum(1)]), witness_program ]
        tx2.wit.vtxinwit[1].scriptWitness.stack = [ CScript([OP_TRUE]) ]

        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx2])

        # This has extra witness data, so it should fail.
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)

        # Now get rid of the extra witness, but add extra scriptSig data
        tx2.vin[0].scriptSig = CScript([OP_TRUE])
        tx2.vin[1].scriptSig = CScript([OP_TRUE])
        tx2.wit.vtxinwit[0].scriptWitness.stack.pop(0)
        tx2.wit.vtxinwit[1].scriptWitness.stack = []
        tx2.rehash()
        add_witness_commitment(block)
        block.solve()

        # This has extra signature data for a witness input, so it should fail.
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)

        # Now get rid of the extra scriptsig on the witness input, and verify
        # success (even with extra scriptsig data in the non-witness input)
        tx2.vin[0].scriptSig = b""
        tx2.rehash()
        add_witness_commitment(block)
        block.solve()

        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        # Update utxo for later tests
        self.utxo.pop(0)
        self.utxo.append(UTXO(tx2.sha256, 0, tx2.vout[0].nValue))


    def test_max_witness_push_length(self):
        ''' Should only allow up to 520 byte pushes in witness stack '''
        self.log.info("Testing maximum witness push size")
        MAX_SCRIPT_ELEMENT_SIZE = 520
        assert(len(self.utxo))

        block = self.build_next_block()

        witness_program = CScript([OP_DROP, OP_TRUE])
        witness_hash = sha256(witness_program)
        scriptPubKey = CScript([OP_0, witness_hash])

        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))
        tx.vout.append(CTxOut(self.utxo[0].nValue-1000, scriptPubKey))
        tx.rehash()

        tx2 = CTransaction()
        tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), b""))
        tx2.vout.append(CTxOut(tx.vout[0].nValue-1000, CScript([OP_TRUE])))
        tx2.wit.vtxinwit.append(CTxInWitness())
        # First try a 521-byte stack element
        tx2.wit.vtxinwit[0].scriptWitness.stack = [ b'a'*(MAX_SCRIPT_ELEMENT_SIZE+1), witness_program ]
        tx2.rehash()

        self.update_witness_block_with_transactions(block, [tx, tx2])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)

        # Now reduce the length of the stack element
        tx2.wit.vtxinwit[0].scriptWitness.stack[0] = b'a'*(MAX_SCRIPT_ELEMENT_SIZE)

        add_witness_commitment(block)
        block.solve()
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        # Update the utxo for later tests
        self.utxo.pop()
        self.utxo.append(UTXO(tx2.sha256, 0, tx2.vout[0].nValue))

    def test_max_witness_program_length(self):
        # Can create witness outputs that are long, but can't be greater than
        # 10k bytes to successfully spend
        self.log.info("Testing maximum witness program length")
        assert(len(self.utxo))
        MAX_PROGRAM_LENGTH = 10000

        # This program is 19 max pushes (9937 bytes), then 64 more opcode-bytes.
        long_witness_program = CScript([b'a'*520]*19 + [OP_DROP]*63 + [OP_TRUE])
        assert(len(long_witness_program) == MAX_PROGRAM_LENGTH+1)
        long_witness_hash = sha256(long_witness_program)
        long_scriptPubKey = CScript([OP_0, long_witness_hash])

        block = self.build_next_block()

        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))
        tx.vout.append(CTxOut(self.utxo[0].nValue-1000, long_scriptPubKey))
        tx.rehash()

        tx2 = CTransaction()
        tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), b""))
        tx2.vout.append(CTxOut(tx.vout[0].nValue-1000, CScript([OP_TRUE])))
        tx2.wit.vtxinwit.append(CTxInWitness())
        tx2.wit.vtxinwit[0].scriptWitness.stack = [b'a']*44 + [long_witness_program]
        tx2.rehash()

        self.update_witness_block_with_transactions(block, [tx, tx2])

        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)

        # Try again with one less byte in the witness program
        witness_program = CScript([b'a'*520]*19 + [OP_DROP]*62 + [OP_TRUE])
        assert(len(witness_program) == MAX_PROGRAM_LENGTH)
        witness_hash = sha256(witness_program)
        scriptPubKey = CScript([OP_0, witness_hash])

        tx.vout[0] = CTxOut(tx.vout[0].nValue, scriptPubKey)
        tx.rehash()
        tx2.vin[0].prevout.hash = tx.sha256
        tx2.wit.vtxinwit[0].scriptWitness.stack = [b'a']*43 + [witness_program]
        tx2.rehash()
        block.vtx = [block.vtx[0]]
        self.update_witness_block_with_transactions(block, [tx, tx2])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        self.utxo.pop()
        self.utxo.append(UTXO(tx2.sha256, 0, tx2.vout[0].nValue))


    def test_witness_input_length(self):
        ''' Ensure that vin length must match vtxinwit length '''
        self.log.info("Testing witness input length")
        assert(len(self.utxo))

        witness_program = CScript([OP_DROP, OP_TRUE])
        witness_hash = sha256(witness_program)
        scriptPubKey = CScript([OP_0, witness_hash])
        
        # Create a transaction that splits our utxo into many outputs
        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))
        nValue = self.utxo[0].nValue
        for i in range(10):
            tx.vout.append(CTxOut(int(nValue/10), scriptPubKey))
        tx.vout[0].nValue -= 1000
        assert(tx.vout[0].nValue >= 0)

        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        # Try various ways to spend tx that should all break.
        # This "broken" transaction serializer will not normalize
        # the length of vtxinwit.
        class BrokenCTransaction(CTransaction):
            def serialize_with_witness(self):
                flags = 0
                if not self.wit.is_null():
                    flags |= 1
                r = b""
                r += struct.pack("<i", self.nVersion)
                if flags:
                    dummy = []
                    r += ser_vector(dummy)
                    r += struct.pack("<B", flags)
                r += ser_vector(self.vin)
                r += ser_vector(self.vout)
                if flags & 1:
                    r += self.wit.serialize()
                r += struct.pack("<I", self.nLockTime)
                return r

        tx2 = BrokenCTransaction()
        for i in range(10):
            tx2.vin.append(CTxIn(COutPoint(tx.sha256, i), b""))
        tx2.vout.append(CTxOut(nValue-3000, CScript([OP_TRUE])))

        # First try using a too long vtxinwit
        for i in range(11):
            tx2.wit.vtxinwit.append(CTxInWitness())
            tx2.wit.vtxinwit[i].scriptWitness.stack = [b'a', witness_program]

        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx2])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)

        # Now try using a too short vtxinwit
        tx2.wit.vtxinwit.pop()
        tx2.wit.vtxinwit.pop()

        block.vtx = [block.vtx[0]]
        self.update_witness_block_with_transactions(block, [tx2])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)

        # Now make one of the intermediate witnesses be incorrect
        tx2.wit.vtxinwit.append(CTxInWitness())
        tx2.wit.vtxinwit[-1].scriptWitness.stack = [b'a', witness_program]
        tx2.wit.vtxinwit[5].scriptWitness.stack = [ witness_program ]

        block.vtx = [block.vtx[0]]
        self.update_witness_block_with_transactions(block, [tx2])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)

        # Fix the broken witness and the block should be accepted.
        tx2.wit.vtxinwit[5].scriptWitness.stack = [b'a', witness_program]
        block.vtx = [block.vtx[0]]
        self.update_witness_block_with_transactions(block, [tx2])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        self.utxo.pop()
        self.utxo.append(UTXO(tx2.sha256, 0, tx2.vout[0].nValue))


    def test_witness_tx_relay_before_segwit_activation(self):
        self.log.info("Testing relay of witness transactions")
        # Generate a transaction that doesn't require a witness, but send it
        # with a witness.  Should be rejected for premature-witness, but should
        # not be added to recently rejected list.
        assert(len(self.utxo))
        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))
        tx.vout.append(CTxOut(self.utxo[0].nValue-1000, CScript([OP_TRUE])))
        tx.wit.vtxinwit.append(CTxInWitness())
        tx.wit.vtxinwit[0].scriptWitness.stack = [ b'a' ]
        tx.rehash()

        tx_hash = tx.sha256
        tx_value = tx.vout[0].nValue

        # Verify that if a peer doesn't set nServices to include NODE_WITNESS,
        # the getdata is just for the non-witness portion.
        self.old_node.announce_tx_and_wait_for_getdata(tx)
        assert(self.old_node.last_message["getdata"].inv[0].type == 1)

        # Since we haven't delivered the tx yet, inv'ing the same tx from
        # a witness transaction ought not result in a getdata.
        try:
            self.test_node.announce_tx_and_wait_for_getdata(tx, timeout=2)
            self.log.error("Error: duplicate tx getdata!")
            assert(False)
        except AssertionError as e:
            pass

        # Delivering this transaction with witness should fail (no matter who
        # its from)
        assert_equal(len(self.nodes[0].getrawmempool()), 0)
        assert_equal(len(self.nodes[1].getrawmempool()), 0)
        test_transaction_acceptance(self.nodes[0].rpc, self.old_node, tx, with_witness=True, accepted=False)
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx, with_witness=True, accepted=False)

        # But eliminating the witness should fix it
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx, with_witness=False, accepted=True)

        # Cleanup: mine the first transaction and update utxo
        self.nodes[0].generate(1)
        assert_equal(len(self.nodes[0].getrawmempool()),  0)

        self.utxo.pop(0)
        self.utxo.append(UTXO(tx_hash, 0, tx_value))


    # After segwit activates, verify that mempool:
    # - rejects transactions with unnecessary/extra witnesses
    # - accepts transactions with valid witnesses
    # and that witness transactions are relayed to non-upgraded peers.
    def test_tx_relay_after_segwit_activation(self):
        self.log.info("Testing relay of witness transactions")
        # Generate a transaction that doesn't require a witness, but send it
        # with a witness.  Should be rejected because we can't use a witness
        # when spending a non-witness output.
        assert(len(self.utxo))
        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))
        tx.vout.append(CTxOut(self.utxo[0].nValue-1000, CScript([OP_TRUE])))
        tx.wit.vtxinwit.append(CTxInWitness())
        tx.wit.vtxinwit[0].scriptWitness.stack = [ b'a' ]
        tx.rehash()

        tx_hash = tx.sha256

        # Verify that unnecessary witnesses are rejected.
        self.test_node.announce_tx_and_wait_for_getdata(tx)
        assert_equal(len(self.nodes[0].getrawmempool()), 0)
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx, with_witness=True, accepted=False)

        # Verify that removing the witness succeeds.
        self.test_node.announce_tx_and_wait_for_getdata(tx)
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx, with_witness=False, accepted=True)

        # Now try to add extra witness data to a valid witness tx.
        witness_program = CScript([OP_TRUE])
        witness_hash = sha256(witness_program)
        scriptPubKey = CScript([OP_0, witness_hash])
        tx2 = CTransaction()
        tx2.vin.append(CTxIn(COutPoint(tx_hash, 0), b""))
        tx2.vout.append(CTxOut(tx.vout[0].nValue-1000, scriptPubKey))
        tx2.rehash()

        tx3 = CTransaction()
        tx3.vin.append(CTxIn(COutPoint(tx2.sha256, 0), b""))
        tx3.wit.vtxinwit.append(CTxInWitness())

        # Add too-large for IsStandard witness and check that it does not enter reject filter
        p2sh_program = CScript([OP_TRUE])
        p2sh_pubkey = hash160(p2sh_program)
        witness_program2 = CScript([b'a'*400000])
        tx3.vout.append(CTxOut(tx2.vout[0].nValue-1000, CScript([OP_HASH160, p2sh_pubkey, OP_EQUAL])))
        tx3.wit.vtxinwit[0].scriptWitness.stack = [witness_program2]
        tx3.rehash()

        # Node will not be blinded to the transaction
        self.std_node.announce_tx_and_wait_for_getdata(tx3)
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, tx3, True, False, b'tx-size')
        self.std_node.announce_tx_and_wait_for_getdata(tx3)
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, tx3, True, False, b'tx-size')

        # Remove witness stuffing, instead add extra witness push on stack
        tx3.vout[0] = CTxOut(tx2.vout[0].nValue-1000, CScript([OP_TRUE]))
        tx3.wit.vtxinwit[0].scriptWitness.stack = [CScript([CScriptNum(1)]), witness_program ]
        tx3.rehash()

        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx2, with_witness=True, accepted=True)
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx3, with_witness=True, accepted=False)

        # Get rid of the extra witness, and verify acceptance.
        tx3.wit.vtxinwit[0].scriptWitness.stack = [ witness_program ]
        # Also check that old_node gets a tx announcement, even though this is
        # a witness transaction.
        self.old_node.wait_for_inv([CInv(1, tx2.sha256)]) # wait until tx2 was inv'ed
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx3, with_witness=True, accepted=True)
        self.old_node.wait_for_inv([CInv(1, tx3.sha256)])

        # Test that getrawtransaction returns correct witness information
        # hash, size, vsize
        raw_tx = self.nodes[0].getrawtransaction(tx3.hash, 1)
        assert_equal(int(raw_tx["hash"], 16), tx3.calc_sha256(True))
        assert_equal(raw_tx["size"], len(tx3.serialize_with_witness()))
        vsize = (len(tx3.serialize_with_witness()) + 3*len(tx3.serialize_without_witness()) + 3) / 4
        assert_equal(raw_tx["vsize"], vsize)
        assert_equal(len(raw_tx["vin"][0]["txinwitness"]), 1)
        assert_equal(raw_tx["vin"][0]["txinwitness"][0], hexlify(witness_program).decode('ascii'))
        assert(vsize != raw_tx["size"])

        # Cleanup: mine the transactions and update utxo for next test
        self.nodes[0].generate(1)
        assert_equal(len(self.nodes[0].getrawmempool()),  0)

        self.utxo.pop(0)
        self.utxo.append(UTXO(tx3.sha256, 0, tx3.vout[0].nValue))


    # Test that block requests to NODE_WITNESS peer are with MSG_WITNESS_FLAG
    # This is true regardless of segwit activation.
    # Also test that we don't ask for blocks from unupgraded peers
    def test_block_relay(self, segwit_activated):
        self.log.info("Testing block relay")

        blocktype = 2|MSG_WITNESS_FLAG

        # test_node has set NODE_WITNESS, so all getdata requests should be for
        # witness blocks.
        # Test announcing a block via inv results in a getdata, and that
        # announcing a version 4 or random VB block with a header results in a getdata
        block1 = self.build_next_block()
        block1.solve()

        self.test_node.announce_block_and_wait_for_getdata(block1, use_header=False)
        assert(self.test_node.last_message["getdata"].inv[0].type == blocktype)
        test_witness_block(self.nodes[0].rpc, self.test_node, block1, True)

        block2 = self.build_next_block(nVersion=4)
        block2.solve()

        self.test_node.announce_block_and_wait_for_getdata(block2, use_header=True)
        assert(self.test_node.last_message["getdata"].inv[0].type == blocktype)
        test_witness_block(self.nodes[0].rpc, self.test_node, block2, True)

        block3 = self.build_next_block(nVersion=(VB_TOP_BITS | (1<<15)))
        block3.solve()
        self.test_node.announce_block_and_wait_for_getdata(block3, use_header=True)
        assert(self.test_node.last_message["getdata"].inv[0].type == blocktype)
        test_witness_block(self.nodes[0].rpc, self.test_node, block3, True)

        # Check that we can getdata for witness blocks or regular blocks,
        # and the right thing happens.
        if segwit_activated == False:
            # Before activation, we should be able to request old blocks with
            # or without witness, and they should be the same.
            chain_height = self.nodes[0].getblockcount()
            # Pick 10 random blocks on main chain, and verify that getdata's
            # for MSG_BLOCK, MSG_WITNESS_BLOCK, and rpc getblock() are equal.
            all_heights = list(range(chain_height+1))
            random.shuffle(all_heights)
            all_heights = all_heights[0:10]
            for height in all_heights:
                block_hash = self.nodes[0].getblockhash(height)
                rpc_block = self.nodes[0].getblock(block_hash, False)
                block_hash = int(block_hash, 16)
                block = self.test_node.request_block(block_hash, 2)
                wit_block = self.test_node.request_block(block_hash, 2|MSG_WITNESS_FLAG)
                assert_equal(block.serialize(True), wit_block.serialize(True))
                assert_equal(block.serialize(), hex_str_to_bytes(rpc_block))
        else:
            # After activation, witness blocks and non-witness blocks should
            # be different.  Verify rpc getblock() returns witness blocks, while
            # getdata respects the requested type.
            block = self.build_next_block()
            self.update_witness_block_with_transactions(block, [])
            # This gives us a witness commitment.
            assert(len(block.vtx[0].wit.vtxinwit) == 1)
            assert(len(block.vtx[0].wit.vtxinwit[0].scriptWitness.stack) == 1)
            test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)
            # Now try to retrieve it...
            rpc_block = self.nodes[0].getblock(block.hash, False)
            non_wit_block = self.test_node.request_block(block.sha256, 2)
            wit_block = self.test_node.request_block(block.sha256, 2|MSG_WITNESS_FLAG)
            assert_equal(wit_block.serialize(True), hex_str_to_bytes(rpc_block))
            assert_equal(wit_block.serialize(False), non_wit_block.serialize())
            assert_equal(wit_block.serialize(True), block.serialize(True))

            # Test size, vsize, weight
            rpc_details = self.nodes[0].getblock(block.hash, True)
            assert_equal(rpc_details["size"], len(block.serialize(True)))
            assert_equal(rpc_details["strippedsize"], len(block.serialize(False)))
            weight = 3*len(block.serialize(False)) + len(block.serialize(True))
            assert_equal(rpc_details["weight"], weight)

            # Upgraded node should not ask for blocks from unupgraded
            block4 = self.build_next_block(nVersion=4)
            block4.solve()
            self.old_node.getdataset = set()

            # Blocks can be requested via direct-fetch (immediately upon processing the announcement)
            # or via parallel download (with an indeterminate delay from processing the announcement)
            # so to test that a block is NOT requested, we could guess a time period to sleep for,
            # and then check. We can avoid the sleep() by taking advantage of transaction getdata's
            # being processed after block getdata's, and announce a transaction as well,
            # and then check to see if that particular getdata has been received.
            # Since 0.14, inv's will only be responded to with a getheaders, so send a header
            # to announce this block.
            msg = msg_headers()
            msg.headers = [ CBlockHeader(block4) ]
            self.old_node.send_message(msg)
            self.old_node.announce_tx_and_wait_for_getdata(block4.vtx[0])
            assert(block4.sha256 not in self.old_node.getdataset)

    # V0 segwit outputs should be standard after activation, but not before.
    def test_standardness_v0(self, segwit_activated):
        self.log.info("Testing standardness of v0 outputs (%s activation)" % ("after" if segwit_activated else "before"))
        assert(len(self.utxo))

        witness_program = CScript([OP_TRUE])
        witness_hash = sha256(witness_program)
        scriptPubKey = CScript([OP_0, witness_hash])

        p2sh_pubkey = hash160(witness_program)
        p2sh_scriptPubKey = CScript([OP_HASH160, p2sh_pubkey, OP_EQUAL])

        # First prepare a p2sh output (so that spending it will pass standardness)
        p2sh_tx = CTransaction()
        p2sh_tx.vin = [CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")]
        p2sh_tx.vout = [CTxOut(self.utxo[0].nValue-1000, p2sh_scriptPubKey)]
        p2sh_tx.rehash()

        # Mine it on test_node to create the confirmed output.
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, p2sh_tx, with_witness=True, accepted=True)
        self.nodes[0].generate(1)
        sync_blocks(self.nodes)

        # Now test standardness of v0 P2WSH outputs.
        # Start by creating a transaction with two outputs.
        tx = CTransaction()
        tx.vin = [CTxIn(COutPoint(p2sh_tx.sha256, 0), CScript([witness_program]))]
        tx.vout = [CTxOut(p2sh_tx.vout[0].nValue-10000, scriptPubKey)]
        tx.vout.append(CTxOut(8000, scriptPubKey)) # Might burn this later
        tx.rehash()

        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, tx, with_witness=True, accepted=segwit_activated)

        # Now create something that looks like a P2PKH output. This won't be spendable.
        scriptPubKey = CScript([OP_0, hash160(witness_hash)])
        tx2 = CTransaction()
        if segwit_activated:
            # if tx was accepted, then we spend the second output.
            tx2.vin = [CTxIn(COutPoint(tx.sha256, 1), b"")]
            tx2.vout = [CTxOut(7000, scriptPubKey)]
            tx2.wit.vtxinwit.append(CTxInWitness())
            tx2.wit.vtxinwit[0].scriptWitness.stack = [witness_program]
        else:
            # if tx wasn't accepted, we just re-spend the p2sh output we started with.
            tx2.vin = [CTxIn(COutPoint(p2sh_tx.sha256, 0), CScript([witness_program]))]
            tx2.vout = [CTxOut(p2sh_tx.vout[0].nValue-1000, scriptPubKey)]
        tx2.rehash()

        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, tx2, with_witness=True, accepted=segwit_activated)

        # Now update self.utxo for later tests.
        tx3 = CTransaction()
        if segwit_activated:
            # tx and tx2 were both accepted.  Don't bother trying to reclaim the
            # P2PKH output; just send tx's first output back to an anyone-can-spend.
            sync_mempools([self.nodes[0], self.nodes[1]])
            tx3.vin = [CTxIn(COutPoint(tx.sha256, 0), b"")]
            tx3.vout = [CTxOut(tx.vout[0].nValue-1000, CScript([OP_TRUE]))]
            tx3.wit.vtxinwit.append(CTxInWitness())
            tx3.wit.vtxinwit[0].scriptWitness.stack = [witness_program]
            tx3.rehash()
            test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx3, with_witness=True, accepted=True)
        else:
            # tx and tx2 didn't go anywhere; just clean up the p2sh_tx output.
            tx3.vin = [CTxIn(COutPoint(p2sh_tx.sha256, 0), CScript([witness_program]))]
            tx3.vout = [CTxOut(p2sh_tx.vout[0].nValue-1000, witness_program)]
            tx3.rehash()
            test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx3, with_witness=True, accepted=True)

        self.nodes[0].generate(1)
        sync_blocks(self.nodes)
        self.utxo.pop(0)
        self.utxo.append(UTXO(tx3.sha256, 0, tx3.vout[0].nValue))
        assert_equal(len(self.nodes[1].getrawmempool()), 0)


    # Verify that future segwit upgraded transactions are non-standard,
    # but valid in blocks. Can run this before and after segwit activation.
    def test_segwit_versions(self):
        self.log.info("Testing standardness/consensus for segwit versions (0-16)")
        assert(len(self.utxo))
        NUM_TESTS = 17 # will test OP_0, OP1, ..., OP_16
        if (len(self.utxo) < NUM_TESTS):
            tx = CTransaction()
            tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))
            split_value = (self.utxo[0].nValue - 4000) // NUM_TESTS
            for i in range(NUM_TESTS):
                tx.vout.append(CTxOut(split_value, CScript([OP_TRUE])))
            tx.rehash()
            block = self.build_next_block()
            self.update_witness_block_with_transactions(block, [tx])
            test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)
            self.utxo.pop(0)
            for i in range(NUM_TESTS):
                self.utxo.append(UTXO(tx.sha256, i, split_value))

        sync_blocks(self.nodes)
        temp_utxo = []
        tx = CTransaction()
        count = 0
        witness_program = CScript([OP_TRUE])
        witness_hash = sha256(witness_program)
        assert_equal(len(self.nodes[1].getrawmempool()), 0)
        for version in list(range(OP_1, OP_16+1)) + [OP_0]:
            count += 1
            # First try to spend to a future version segwit scriptPubKey.
            scriptPubKey = CScript([CScriptOp(version), witness_hash])
            tx.vin = [CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")]
            tx.vout = [CTxOut(self.utxo[0].nValue-1000, scriptPubKey)]
            tx.rehash()
            test_transaction_acceptance(self.nodes[1].rpc, self.std_node, tx, with_witness=True, accepted=False)
            test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx, with_witness=True, accepted=True)
            self.utxo.pop(0)
            temp_utxo.append(UTXO(tx.sha256, 0, tx.vout[0].nValue))

        self.nodes[0].generate(1) # Mine all the transactions
        sync_blocks(self.nodes)
        assert(len(self.nodes[0].getrawmempool()) == 0)

        # Finally, verify that version 0 -> version 1 transactions
        # are non-standard
        scriptPubKey = CScript([CScriptOp(OP_1), witness_hash])
        tx2 = CTransaction()
        tx2.vin = [CTxIn(COutPoint(tx.sha256, 0), b"")]
        tx2.vout = [CTxOut(tx.vout[0].nValue-1000, scriptPubKey)]
        tx2.wit.vtxinwit.append(CTxInWitness())
        tx2.wit.vtxinwit[0].scriptWitness.stack = [ witness_program ]
        tx2.rehash()
        # Gets accepted to test_node, because standardness of outputs isn't
        # checked with fRequireStandard
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx2, with_witness=True, accepted=True)
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, tx2, with_witness=True, accepted=False)
        temp_utxo.pop() # last entry in temp_utxo was the output we just spent
        temp_utxo.append(UTXO(tx2.sha256, 0, tx2.vout[0].nValue))

        # Spend everything in temp_utxo back to an OP_TRUE output.
        tx3 = CTransaction()
        total_value = 0
        for i in temp_utxo:
            tx3.vin.append(CTxIn(COutPoint(i.sha256, i.n), b""))
            tx3.wit.vtxinwit.append(CTxInWitness())
            total_value += i.nValue
        tx3.wit.vtxinwit[-1].scriptWitness.stack = [witness_program]
        tx3.vout.append(CTxOut(total_value - 1000, CScript([OP_TRUE])))
        tx3.rehash()
        # Spending a higher version witness output is not allowed by policy,
        # even with fRequireStandard=false.
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx3, with_witness=True, accepted=False)
        self.test_node.sync_with_ping()
        with mininode_lock:
            assert(b"reserved for soft-fork upgrades" in self.test_node.last_message["reject"].reason)

        # Building a block with the transaction must be valid, however.
        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx2, tx3])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)
        sync_blocks(self.nodes)

        # Add utxo to our list
        self.utxo.append(UTXO(tx3.sha256, 0, tx3.vout[0].nValue))


    def test_premature_coinbase_witness_spend(self):
        self.log.info("Testing premature coinbase witness spend")
        block = self.build_next_block()
        # Change the output of the block to be a witness output.
        witness_program = CScript([OP_TRUE])
        witness_hash = sha256(witness_program)
        scriptPubKey = CScript([OP_0, witness_hash])
        block.vtx[0].vout[0].scriptPubKey = scriptPubKey
        # This next line will rehash the coinbase and update the merkle
        # root, and solve.
        self.update_witness_block_with_transactions(block, [])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        spend_tx = CTransaction()
        spend_tx.vin = [CTxIn(COutPoint(block.vtx[0].sha256, 0), b"")]
        spend_tx.vout = [CTxOut(block.vtx[0].vout[0].nValue, witness_program)]
        spend_tx.wit.vtxinwit.append(CTxInWitness())
        spend_tx.wit.vtxinwit[0].scriptWitness.stack = [ witness_program ]
        spend_tx.rehash()

        # Now test a premature spend.
        self.nodes[0].generate(98)
        sync_blocks(self.nodes)
        block2 = self.build_next_block()
        self.update_witness_block_with_transactions(block2, [spend_tx])
        test_witness_block(self.nodes[0].rpc, self.test_node, block2, accepted=False)

        # Advancing one more block should allow the spend.
        self.nodes[0].generate(1)
        block2 = self.build_next_block()
        self.update_witness_block_with_transactions(block2, [spend_tx])
        test_witness_block(self.nodes[0].rpc, self.test_node, block2, accepted=True)
        sync_blocks(self.nodes)


    def test_signature_version_1(self):
        self.log.info("Testing segwit signature hash version 1")
        key = CECKey()
        key.set_secretbytes(b"9")
        pubkey = CPubKey(key.get_pubkey())

        witness_program = CScript([pubkey, CScriptOp(OP_CHECKSIG)])
        witness_hash = sha256(witness_program)
        scriptPubKey = CScript([OP_0, witness_hash])

        # First create a witness output for use in the tests.
        assert(len(self.utxo))
        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))
        tx.vout.append(CTxOut(self.utxo[0].nValue-1000, scriptPubKey))
        tx.rehash()

        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx, with_witness=True, accepted=True)
        # Mine this transaction in preparation for following tests.
        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)
        sync_blocks(self.nodes)
        self.utxo.pop(0)

        # Test each hashtype
        prev_utxo = UTXO(tx.sha256, 0, tx.vout[0].nValue)
        for sigflag in [ 0, SIGHASH_ANYONECANPAY ]:
            for hashtype in [SIGHASH_ALL, SIGHASH_NONE, SIGHASH_SINGLE]:
                hashtype |= sigflag
                block = self.build_next_block()
                tx = CTransaction()
                tx.vin.append(CTxIn(COutPoint(prev_utxo.sha256, prev_utxo.n), b""))
                tx.vout.append(CTxOut(prev_utxo.nValue - 1000, scriptPubKey))
                tx.wit.vtxinwit.append(CTxInWitness())
                # Too-large input value
                sign_P2PK_witness_input(witness_program, tx, 0, hashtype, prev_utxo.nValue+1, key)
                self.update_witness_block_with_transactions(block, [tx])
                test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)

                # Too-small input value
                sign_P2PK_witness_input(witness_program, tx, 0, hashtype, prev_utxo.nValue-1, key)
                block.vtx.pop() # remove last tx
                self.update_witness_block_with_transactions(block, [tx])
                test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)

                # Now try correct value
                sign_P2PK_witness_input(witness_program, tx, 0, hashtype, prev_utxo.nValue, key)
                block.vtx.pop()
                self.update_witness_block_with_transactions(block, [tx])
                test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

                prev_utxo = UTXO(tx.sha256, 0, tx.vout[0].nValue)

        # Test combinations of signature hashes.
        # Split the utxo into a lot of outputs.
        # Randomly choose up to 10 to spend, sign with different hashtypes, and
        # output to a random number of outputs.  Repeat NUM_TESTS times.
        # Ensure that we've tested a situation where we use SIGHASH_SINGLE with
        # an input index > number of outputs.
        NUM_TESTS = 500
        temp_utxos = []
        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(prev_utxo.sha256, prev_utxo.n), b""))
        split_value = prev_utxo.nValue // NUM_TESTS
        for i in range(NUM_TESTS):
            tx.vout.append(CTxOut(split_value, scriptPubKey))
        tx.wit.vtxinwit.append(CTxInWitness())
        sign_P2PK_witness_input(witness_program, tx, 0, SIGHASH_ALL, prev_utxo.nValue, key)
        for i in range(NUM_TESTS):
            temp_utxos.append(UTXO(tx.sha256, i, split_value))

        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        block = self.build_next_block()
        used_sighash_single_out_of_bounds = False
        for i in range(NUM_TESTS):
            # Ping regularly to keep the connection alive
            if (not i % 100):
                self.test_node.sync_with_ping()
            # Choose random number of inputs to use.
            num_inputs = random.randint(1, 10)
            # Create a slight bias for producing more utxos
            num_outputs = random.randint(1, 11)
            random.shuffle(temp_utxos)
            assert(len(temp_utxos) > num_inputs)
            tx = CTransaction()
            total_value = 0
            for i in range(num_inputs):
                tx.vin.append(CTxIn(COutPoint(temp_utxos[i].sha256, temp_utxos[i].n), b""))
                tx.wit.vtxinwit.append(CTxInWitness())
                total_value += temp_utxos[i].nValue
            split_value = total_value // num_outputs
            for i in range(num_outputs):
                tx.vout.append(CTxOut(split_value, scriptPubKey))
            for i in range(num_inputs):
                # Now try to sign each input, using a random hashtype.
                anyonecanpay = 0
                if random.randint(0, 1):
                    anyonecanpay = SIGHASH_ANYONECANPAY
                hashtype = random.randint(1, 3) | anyonecanpay
                sign_P2PK_witness_input(witness_program, tx, i, hashtype, temp_utxos[i].nValue, key)
                if (hashtype == SIGHASH_SINGLE and i >= num_outputs):
                    used_sighash_single_out_of_bounds = True
            tx.rehash()
            for i in range(num_outputs):
                temp_utxos.append(UTXO(tx.sha256, i, split_value))
            temp_utxos = temp_utxos[num_inputs:]

            block.vtx.append(tx)

            # Test the block periodically, if we're close to maxblocksize
            if (get_virtual_size(block) > MAX_BLOCK_BASE_SIZE - 1000):
                self.update_witness_block_with_transactions(block, [])
                test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)
                block = self.build_next_block()

        if (not used_sighash_single_out_of_bounds):
            self.log.info("WARNING: this test run didn't attempt SIGHASH_SINGLE with out-of-bounds index value")
        # Test the transactions we've added to the block
        if (len(block.vtx) > 1):
            self.update_witness_block_with_transactions(block, [])
            test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        # Now test witness version 0 P2PKH transactions
        pubkeyhash = hash160(pubkey)
        scriptPKH = CScript([OP_0, pubkeyhash])
        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(temp_utxos[0].sha256, temp_utxos[0].n), b""))
        tx.vout.append(CTxOut(temp_utxos[0].nValue, scriptPKH))
        tx.wit.vtxinwit.append(CTxInWitness())
        sign_P2PK_witness_input(witness_program, tx, 0, SIGHASH_ALL, temp_utxos[0].nValue, key)
        tx2 = CTransaction()
        tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), b""))
        tx2.vout.append(CTxOut(tx.vout[0].nValue, CScript([OP_TRUE])))

        script = GetP2PKHScript(pubkeyhash)
        sig_hash = SegwitVersion1SignatureHash(script, tx2, 0, SIGHASH_ALL, tx.vout[0].nValue)
        signature = key.sign(sig_hash) + b'\x01' # 0x1 is SIGHASH_ALL

        # Check that we can't have a scriptSig
        tx2.vin[0].scriptSig = CScript([signature, pubkey])
        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx, tx2])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=False)

        # Move the signature to the witness.
        block.vtx.pop()
        tx2.wit.vtxinwit.append(CTxInWitness())
        tx2.wit.vtxinwit[0].scriptWitness.stack = [signature, pubkey]
        tx2.vin[0].scriptSig = b""
        tx2.rehash()

        self.update_witness_block_with_transactions(block, [tx2])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        temp_utxos.pop(0)

        # Update self.utxos for later tests. Just spend everything in
        # temp_utxos to a corresponding entry in self.utxos
        tx = CTransaction()
        index = 0
        for i in temp_utxos:
            # Just spend to our usual anyone-can-spend output
            # Use SIGHASH_SINGLE|SIGHASH_ANYONECANPAY so we can build up
            # the signatures as we go.
            tx.vin.append(CTxIn(COutPoint(i.sha256, i.n), b""))
            tx.vout.append(CTxOut(i.nValue, CScript([OP_TRUE])))
            tx.wit.vtxinwit.append(CTxInWitness())
            sign_P2PK_witness_input(witness_program, tx, index, SIGHASH_SINGLE|SIGHASH_ANYONECANPAY, i.nValue, key)
            index += 1
        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        for i in range(len(tx.vout)):
            self.utxo.append(UTXO(tx.sha256, i, tx.vout[i].nValue))


    # Test P2SH wrapped witness programs.
    def test_p2sh_witness(self, segwit_activated):
        self.log.info("Testing P2SH witness transactions")

        assert(len(self.utxo))

        # Prepare the p2sh-wrapped witness output
        witness_program = CScript([OP_DROP, OP_TRUE])
        witness_hash = sha256(witness_program)
        p2wsh_pubkey = CScript([OP_0, witness_hash])
        p2sh_witness_hash = hash160(p2wsh_pubkey)
        scriptPubKey = CScript([OP_HASH160, p2sh_witness_hash, OP_EQUAL])
        scriptSig = CScript([p2wsh_pubkey]) # a push of the redeem script

        # Fund the P2SH output
        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))
        tx.vout.append(CTxOut(self.utxo[0].nValue-1000, scriptPubKey))
        tx.rehash()

        # Verify mempool acceptance and block validity
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx, with_witness=False, accepted=True)
        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True, with_witness=segwit_activated)
        sync_blocks(self.nodes)

        # Now test attempts to spend the output.
        spend_tx = CTransaction()
        spend_tx.vin.append(CTxIn(COutPoint(tx.sha256, 0), scriptSig))
        spend_tx.vout.append(CTxOut(tx.vout[0].nValue-1000, CScript([OP_TRUE])))
        spend_tx.rehash()

        # This transaction should not be accepted into the mempool pre- or
        # post-segwit.  Mempool acceptance will use SCRIPT_VERIFY_WITNESS which
        # will require a witness to spend a witness program regardless of
        # segwit activation.  Note that older bitcoind's that are not
        # segwit-aware would also reject this for failing CLEANSTACK.
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, spend_tx, with_witness=False, accepted=False)

        # Try to put the witness script in the scriptSig, should also fail.
        spend_tx.vin[0].scriptSig = CScript([p2wsh_pubkey, b'a'])
        spend_tx.rehash()
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, spend_tx, with_witness=False, accepted=False)

        # Now put the witness script in the witness, should succeed after
        # segwit activates.
        spend_tx.vin[0].scriptSig = scriptSig
        spend_tx.rehash()
        spend_tx.wit.vtxinwit.append(CTxInWitness())
        spend_tx.wit.vtxinwit[0].scriptWitness.stack = [ b'a', witness_program ]

        # Verify mempool acceptance
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, spend_tx, with_witness=True, accepted=segwit_activated)
        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [spend_tx])

        # If we're before activation, then sending this without witnesses
        # should be valid.  If we're after activation, then sending this with
        # witnesses should be valid.
        if segwit_activated:
            test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)
        else:
            test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True, with_witness=False)

        # Update self.utxo
        self.utxo.pop(0)
        self.utxo.append(UTXO(spend_tx.sha256, 0, spend_tx.vout[0].nValue))

    # Test the behavior of starting up a segwit-aware node after the softfork
    # has activated.  As segwit requires different block data than pre-segwit
    # nodes would have stored, this requires special handling.
    # To enable this test, pass --oldbinary=<path-to-pre-segwit-bitcoind> to
    # the test.
    def test_upgrade_after_activation(self, node_id):
        self.log.info("Testing software upgrade after softfork activation")

        assert(node_id != 0) # node0 is assumed to be a segwit-active bitcoind

        # Make sure the nodes are all up
        sync_blocks(self.nodes)

        # Restart with the new binary
        self.stop_node(node_id)
        self.start_node(node_id, extra_args=["-vbparams=segwit:0:999999999999"])
        connect_nodes(self.nodes[0], node_id)

        sync_blocks(self.nodes)

        # Make sure that this peer thinks segwit has activated.
        assert(get_bip9_status(self.nodes[node_id], 'segwit')['status'] == "active")

        # Make sure this peers blocks match those of node0.
        height = self.nodes[node_id].getblockcount()
        while height >= 0:
            block_hash = self.nodes[node_id].getblockhash(height)
            assert_equal(block_hash, self.nodes[0].getblockhash(height))
            assert_equal(self.nodes[0].getblock(block_hash), self.nodes[node_id].getblock(block_hash))
            height -= 1


    def test_witness_sigops(self):
        '''Ensure sigop counting is correct inside witnesses.'''
        self.log.info("Testing sigops limit")

        assert(len(self.utxo))

        # Keep this under MAX_OPS_PER_SCRIPT (201)
        witness_program = CScript([OP_TRUE, OP_IF, OP_TRUE, OP_ELSE] + [OP_CHECKMULTISIG]*5 + [OP_CHECKSIG]*193 + [OP_ENDIF])
        witness_hash = sha256(witness_program)
        scriptPubKey = CScript([OP_0, witness_hash])

        sigops_per_script = 20*5 + 193*1
        # We'll produce 2 extra outputs, one with a program that would take us
        # over max sig ops, and one with a program that would exactly reach max
        # sig ops
        outputs = (MAX_SIGOP_COST // sigops_per_script) + 2
        extra_sigops_available = MAX_SIGOP_COST % sigops_per_script

        # We chose the number of checkmultisigs/checksigs to make this work:
        assert(extra_sigops_available < 100) # steer clear of MAX_OPS_PER_SCRIPT

        # This script, when spent with the first
        # N(=MAX_SIGOP_COST//sigops_per_script) outputs of our transaction,
        # would push us just over the block sigop limit.
        witness_program_toomany = CScript([OP_TRUE, OP_IF, OP_TRUE, OP_ELSE] + [OP_CHECKSIG]*(extra_sigops_available + 1) + [OP_ENDIF])
        witness_hash_toomany = sha256(witness_program_toomany)
        scriptPubKey_toomany = CScript([OP_0, witness_hash_toomany])

        # If we spend this script instead, we would exactly reach our sigop
        # limit (for witness sigops).
        witness_program_justright = CScript([OP_TRUE, OP_IF, OP_TRUE, OP_ELSE] + [OP_CHECKSIG]*(extra_sigops_available) + [OP_ENDIF])
        witness_hash_justright = sha256(witness_program_justright)
        scriptPubKey_justright = CScript([OP_0, witness_hash_justright])

        # First split our available utxo into a bunch of outputs
        split_value = self.utxo[0].nValue // outputs
        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))
        for i in range(outputs):
            tx.vout.append(CTxOut(split_value, scriptPubKey))
        tx.vout[-2].scriptPubKey = scriptPubKey_toomany
        tx.vout[-1].scriptPubKey = scriptPubKey_justright
        tx.rehash()

        block_1 = self.build_next_block()
        self.update_witness_block_with_transactions(block_1, [tx])
        test_witness_block(self.nodes[0].rpc, self.test_node, block_1, accepted=True)

        tx2 = CTransaction()
        # If we try to spend the first n-1 outputs from tx, that should be
        # too many sigops.
        total_value = 0
        for i in range(outputs-1):
            tx2.vin.append(CTxIn(COutPoint(tx.sha256, i), b""))
            tx2.wit.vtxinwit.append(CTxInWitness())
            tx2.wit.vtxinwit[-1].scriptWitness.stack = [ witness_program ]
            total_value += tx.vout[i].nValue
        tx2.wit.vtxinwit[-1].scriptWitness.stack = [ witness_program_toomany ] 
        tx2.vout.append(CTxOut(total_value, CScript([OP_TRUE])))
        tx2.rehash()

        block_2 = self.build_next_block()
        self.update_witness_block_with_transactions(block_2, [tx2])
        test_witness_block(self.nodes[0].rpc, self.test_node, block_2, accepted=False)

        # Try dropping the last input in tx2, and add an output that has
        # too many sigops (contributing to legacy sigop count).
        checksig_count = (extra_sigops_available // 4) + 1
        scriptPubKey_checksigs = CScript([OP_CHECKSIG]*checksig_count)
        tx2.vout.append(CTxOut(0, scriptPubKey_checksigs))
        tx2.vin.pop()
        tx2.wit.vtxinwit.pop()
        tx2.vout[0].nValue -= tx.vout[-2].nValue
        tx2.rehash()
        block_3 = self.build_next_block()
        self.update_witness_block_with_transactions(block_3, [tx2])
        test_witness_block(self.nodes[0].rpc, self.test_node, block_3, accepted=False)

        # If we drop the last checksig in this output, the tx should succeed.
        block_4 = self.build_next_block()
        tx2.vout[-1].scriptPubKey = CScript([OP_CHECKSIG]*(checksig_count-1))
        tx2.rehash()
        self.update_witness_block_with_transactions(block_4, [tx2])
        test_witness_block(self.nodes[0].rpc, self.test_node, block_4, accepted=True)

        # Reset the tip back down for the next test
        sync_blocks(self.nodes)
        for x in self.nodes:
            x.invalidateblock(block_4.hash)

        # Try replacing the last input of tx2 to be spending the last
        # output of tx
        block_5 = self.build_next_block()
        tx2.vout.pop()
        tx2.vin.append(CTxIn(COutPoint(tx.sha256, outputs-1), b""))
        tx2.wit.vtxinwit.append(CTxInWitness())
        tx2.wit.vtxinwit[-1].scriptWitness.stack = [ witness_program_justright ]
        tx2.rehash()
        self.update_witness_block_with_transactions(block_5, [tx2])
        test_witness_block(self.nodes[0].rpc, self.test_node, block_5, accepted=True)

        # TODO: test p2sh sigop counting

    def test_getblocktemplate_before_lockin(self):
        self.log.info("Testing getblocktemplate setting of segwit versionbit (before lockin)")
        # Node0 is segwit aware, node2 is not.
        for node in [self.nodes[0], self.nodes[2]]:
            gbt_results = node.getblocktemplate()
            block_version = gbt_results['version']
            # If we're not indicating segwit support, we will still be
            # signalling for segwit activation.
            assert_equal((block_version & (1 << VB_WITNESS_BIT) != 0), node == self.nodes[0])
            # If we don't specify the segwit rule, then we won't get a default
            # commitment.
            assert('default_witness_commitment' not in gbt_results)

        # Workaround:
        # Can either change the tip, or change the mempool and wait 5 seconds
        # to trigger a recomputation of getblocktemplate.
        txid = int(self.nodes[0].sendtoaddress(self.nodes[0].getnewaddress(), 1), 16)
        # Using mocktime lets us avoid sleep()
        sync_mempools(self.nodes)
        self.nodes[0].setmocktime(int(time.time())+10)
        self.nodes[2].setmocktime(int(time.time())+10)

        for node in [self.nodes[0], self.nodes[2]]:
            gbt_results = node.getblocktemplate({"rules" : ["segwit"]})
            block_version = gbt_results['version']
            if node == self.nodes[2]:
                # If this is a non-segwit node, we should still not get a witness
                # commitment, nor a version bit signalling segwit.
                assert_equal(block_version & (1 << VB_WITNESS_BIT), 0)
                assert('default_witness_commitment' not in gbt_results)
            else:
                # For segwit-aware nodes, check the version bit and the witness
                # commitment are correct.
                assert(block_version & (1 << VB_WITNESS_BIT) != 0)
                assert('default_witness_commitment' in gbt_results)
                witness_commitment = gbt_results['default_witness_commitment']

                # Check that default_witness_commitment is present.
                witness_root = CBlock.get_merkle_root([ser_uint256(0),
                                                       ser_uint256(txid)])
                script = get_witness_script(witness_root, 0)
                assert_equal(witness_commitment, bytes_to_hex_str(script))

        # undo mocktime
        self.nodes[0].setmocktime(0)
        self.nodes[2].setmocktime(0)

    # Uncompressed pubkeys are no longer supported in default relay policy,
    # but (for now) are still valid in blocks.
    def test_uncompressed_pubkey(self):
        self.log.info("Testing uncompressed pubkeys")
        # Segwit transactions using uncompressed pubkeys are not accepted
        # under default policy, but should still pass consensus.
        key = CECKey()
        key.set_secretbytes(b"9")
        key.set_compressed(False)
        pubkey = CPubKey(key.get_pubkey())
        assert_equal(len(pubkey), 65) # This should be an uncompressed pubkey

        assert(len(self.utxo) > 0)
        utxo = self.utxo.pop(0)

        # Test 1: P2WPKH
        # First create a P2WPKH output that uses an uncompressed pubkey
        pubkeyhash = hash160(pubkey)
        scriptPKH = CScript([OP_0, pubkeyhash])
        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(utxo.sha256, utxo.n), b""))
        tx.vout.append(CTxOut(utxo.nValue-1000, scriptPKH))
        tx.rehash()

        # Confirm it in a block.
        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        # Now try to spend it. Send it to a P2WSH output, which we'll
        # use in the next test.
        witness_program = CScript([pubkey, CScriptOp(OP_CHECKSIG)])
        witness_hash = sha256(witness_program)
        scriptWSH = CScript([OP_0, witness_hash])

        tx2 = CTransaction()
        tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), b""))
        tx2.vout.append(CTxOut(tx.vout[0].nValue-1000, scriptWSH))
        script = GetP2PKHScript(pubkeyhash)
        sig_hash = SegwitVersion1SignatureHash(script, tx2, 0, SIGHASH_ALL, tx.vout[0].nValue)
        signature = key.sign(sig_hash) + b'\x01' # 0x1 is SIGHASH_ALL
        tx2.wit.vtxinwit.append(CTxInWitness())
        tx2.wit.vtxinwit[0].scriptWitness.stack = [ signature, pubkey ]
        tx2.rehash()

        # Should fail policy test.
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx2, True, False, b'non-mandatory-script-verify-flag (Using non-compressed keys in segwit)')
        # But passes consensus.
        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx2])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        # Test 2: P2WSH
        # Try to spend the P2WSH output created in last test.
        # Send it to a P2SH(P2WSH) output, which we'll use in the next test.
        p2sh_witness_hash = hash160(scriptWSH)
        scriptP2SH = CScript([OP_HASH160, p2sh_witness_hash, OP_EQUAL])
        scriptSig = CScript([scriptWSH])

        tx3 = CTransaction()
        tx3.vin.append(CTxIn(COutPoint(tx2.sha256, 0), b""))
        tx3.vout.append(CTxOut(tx2.vout[0].nValue-1000, scriptP2SH))
        tx3.wit.vtxinwit.append(CTxInWitness())
        sign_P2PK_witness_input(witness_program, tx3, 0, SIGHASH_ALL, tx2.vout[0].nValue, key)

        # Should fail policy test.
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx3, True, False, b'non-mandatory-script-verify-flag (Using non-compressed keys in segwit)')
        # But passes consensus.
        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx3])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        # Test 3: P2SH(P2WSH)
        # Try to spend the P2SH output created in the last test.
        # Send it to a P2PKH output, which we'll use in the next test.
        scriptPubKey = GetP2PKHScript(pubkeyhash)
        tx4 = CTransaction()
        tx4.vin.append(CTxIn(COutPoint(tx3.sha256, 0), scriptSig))
        tx4.vout.append(CTxOut(tx3.vout[0].nValue-1000, scriptPubKey))
        tx4.wit.vtxinwit.append(CTxInWitness())
        sign_P2PK_witness_input(witness_program, tx4, 0, SIGHASH_ALL, tx3.vout[0].nValue, key)

        # Should fail policy test.
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx4, True, False, b'non-mandatory-script-verify-flag (Using non-compressed keys in segwit)')
        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx4])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)

        # Test 4: Uncompressed pubkeys should still be valid in non-segwit
        # transactions.
        tx5 = CTransaction()
        tx5.vin.append(CTxIn(COutPoint(tx4.sha256, 0), b""))
        tx5.vout.append(CTxOut(tx4.vout[0].nValue-1000, CScript([OP_TRUE])))
        (sig_hash, err) = SignatureHash(scriptPubKey, tx5, 0, SIGHASH_ALL)
        signature = key.sign(sig_hash) + b'\x01' # 0x1 is SIGHASH_ALL
        tx5.vin[0].scriptSig = CScript([signature, pubkey])
        tx5.rehash()
        # Should pass policy and consensus.
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx5, True, True)
        block = self.build_next_block()
        self.update_witness_block_with_transactions(block, [tx5])
        test_witness_block(self.nodes[0].rpc, self.test_node, block, accepted=True)
        self.utxo.append(UTXO(tx5.sha256, 0, tx5.vout[0].nValue))

    def test_non_standard_witness(self):
        self.log.info("Testing detection of non-standard P2WSH witness")
        pad = chr(1).encode('latin-1')

        # Create scripts for tests
        scripts = []
        scripts.append(CScript([OP_DROP] * 100))
        scripts.append(CScript([OP_DROP] * 99))
        scripts.append(CScript([pad * 59] * 59 + [OP_DROP] * 60))
        scripts.append(CScript([pad * 59] * 59 + [OP_DROP] * 61))

        p2wsh_scripts = []

        assert(len(self.utxo))
        tx = CTransaction()
        tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))

        # For each script, generate a pair of P2WSH and P2SH-P2WSH output.
        outputvalue = (self.utxo[0].nValue - 1000) // (len(scripts) * 2)
        for i in scripts:
            p2wsh = CScript([OP_0, sha256(i)])
            p2sh = hash160(p2wsh)
            p2wsh_scripts.append(p2wsh)
            tx.vout.append(CTxOut(outputvalue, p2wsh))
            tx.vout.append(CTxOut(outputvalue, CScript([OP_HASH160, p2sh, OP_EQUAL])))
        tx.rehash()
        txid = tx.sha256
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, tx, with_witness=False, accepted=True)

        self.nodes[0].generate(1)
        sync_blocks(self.nodes)

        # Creating transactions for tests
        p2wsh_txs = []
        p2sh_txs = []
        for i in range(len(scripts)):
            p2wsh_tx = CTransaction()
            p2wsh_tx.vin.append(CTxIn(COutPoint(txid,i*2)))
            p2wsh_tx.vout.append(CTxOut(outputvalue - 5000, CScript([OP_0, hash160(hex_str_to_bytes(""))])))
            p2wsh_tx.wit.vtxinwit.append(CTxInWitness())
            p2wsh_tx.rehash()
            p2wsh_txs.append(p2wsh_tx)
            p2sh_tx = CTransaction()
            p2sh_tx.vin.append(CTxIn(COutPoint(txid,i*2+1), CScript([p2wsh_scripts[i]])))
            p2sh_tx.vout.append(CTxOut(outputvalue - 5000, CScript([OP_0, hash160(hex_str_to_bytes(""))])))
            p2sh_tx.wit.vtxinwit.append(CTxInWitness())
            p2sh_tx.rehash()
            p2sh_txs.append(p2sh_tx)

        # Testing native P2WSH
        # Witness stack size, excluding witnessScript, over 100 is non-standard
        p2wsh_txs[0].wit.vtxinwit[0].scriptWitness.stack = [pad] * 101 + [scripts[0]]
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, p2wsh_txs[0], True, False, b'bad-witness-nonstandard')
        # Non-standard nodes should accept
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, p2wsh_txs[0], True, True)

        # Stack element size over 80 bytes is non-standard
        p2wsh_txs[1].wit.vtxinwit[0].scriptWitness.stack = [pad * 81] * 100 + [scripts[1]]
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, p2wsh_txs[1], True, False, b'bad-witness-nonstandard')
        # Non-standard nodes should accept
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, p2wsh_txs[1], True, True)
        # Standard nodes should accept if element size is not over 80 bytes
        p2wsh_txs[1].wit.vtxinwit[0].scriptWitness.stack = [pad * 80] * 100 + [scripts[1]]
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, p2wsh_txs[1], True, True)

        # witnessScript size at 3600 bytes is standard
        p2wsh_txs[2].wit.vtxinwit[0].scriptWitness.stack = [pad, pad, scripts[2]]
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, p2wsh_txs[2], True, True)
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, p2wsh_txs[2], True, True)

        # witnessScript size at 3601 bytes is non-standard
        p2wsh_txs[3].wit.vtxinwit[0].scriptWitness.stack = [pad, pad, pad, scripts[3]]
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, p2wsh_txs[3], True, False, b'bad-witness-nonstandard')
        # Non-standard nodes should accept
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, p2wsh_txs[3], True, True)

        # Repeating the same tests with P2SH-P2WSH
        p2sh_txs[0].wit.vtxinwit[0].scriptWitness.stack = [pad] * 101 + [scripts[0]]
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, p2sh_txs[0], True, False, b'bad-witness-nonstandard')
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, p2sh_txs[0], True, True)
        p2sh_txs[1].wit.vtxinwit[0].scriptWitness.stack = [pad * 81] * 100 + [scripts[1]]
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, p2sh_txs[1], True, False, b'bad-witness-nonstandard')
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, p2sh_txs[1], True, True)
        p2sh_txs[1].wit.vtxinwit[0].scriptWitness.stack = [pad * 80] * 100 + [scripts[1]]
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, p2sh_txs[1], True, True)
        p2sh_txs[2].wit.vtxinwit[0].scriptWitness.stack = [pad, pad, scripts[2]]
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, p2sh_txs[2], True, True)
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, p2sh_txs[2], True, True)
        p2sh_txs[3].wit.vtxinwit[0].scriptWitness.stack = [pad, pad, pad, scripts[3]]
        test_transaction_acceptance(self.nodes[1].rpc, self.std_node, p2sh_txs[3], True, False, b'bad-witness-nonstandard')
        test_transaction_acceptance(self.nodes[0].rpc, self.test_node, p2sh_txs[3], True, True)

        self.nodes[0].generate(1)  # Mine and clean up the mempool of non-standard node
        # Valid but non-standard transactions in a block should be accepted by standard node
        sync_blocks(self.nodes)
        assert_equal(len(self.nodes[0].getrawmempool()), 0)
        assert_equal(len(self.nodes[1].getrawmempool()), 0)

        self.utxo.pop(0)


    def run_test(self):
        # Setup the p2p connections and start up the network thread.
        # self.test_node sets NODE_WITNESS|NODE_NETWORK
        self.test_node = self.nodes[0].add_p2p_connection(TestNode(), services=NODE_NETWORK|NODE_WITNESS)
        # self.old_node sets only NODE_NETWORK
        self.old_node = self.nodes[0].add_p2p_connection(TestNode(), services=NODE_NETWORK)
        # self.std_node is for testing node1 (fRequireStandard=true)
        self.std_node = self.nodes[1].add_p2p_connection(TestNode(), services=NODE_NETWORK|NODE_WITNESS)

        network_thread_start()

        # Keep a place to store utxo's that can be used in later tests
        self.utxo = []

        # Test logic begins here
        self.test_node.wait_for_verack()

        self.log.info("Starting tests before segwit lock in:")

        self.test_witness_services() # Verifies NODE_WITNESS
        self.test_non_witness_transaction() # non-witness tx's are accepted
        self.test_unnecessary_witness_before_segwit_activation()
        self.test_block_relay(segwit_activated=False)

        # Advance to segwit being 'started'
        self.advance_to_segwit_started()
        sync_blocks(self.nodes)
        self.test_getblocktemplate_before_lockin()

        sync_blocks(self.nodes)

        # At lockin, nothing should change.
        self.log.info("Testing behavior post lockin, pre-activation")
        self.advance_to_segwit_lockin()

        # Retest unnecessary witnesses
        self.test_unnecessary_witness_before_segwit_activation()
        self.test_witness_tx_relay_before_segwit_activation()
        self.test_block_relay(segwit_activated=False)
        self.test_p2sh_witness(segwit_activated=False)
        self.test_standardness_v0(segwit_activated=False)

        sync_blocks(self.nodes)

        # Now activate segwit
        self.log.info("Testing behavior after segwit activation")
        self.advance_to_segwit_active()

        sync_blocks(self.nodes)

        # Test P2SH witness handling again
        self.test_p2sh_witness(segwit_activated=True)
        self.test_witness_commitments()
        self.test_block_malleability()
        self.test_witness_block_size()
        self.test_submit_block()
        self.test_extra_witness_data()
        self.test_max_witness_push_length()
        self.test_max_witness_program_length()
        self.test_witness_input_length()
        self.test_block_relay(segwit_activated=True)
        self.test_tx_relay_after_segwit_activation()
        self.test_standardness_v0(segwit_activated=True)
        self.test_segwit_versions()
        self.test_premature_coinbase_witness_spend()
        self.test_uncompressed_pubkey()
        self.test_signature_version_1()
        self.test_non_standard_witness()
        sync_blocks(self.nodes)
        self.test_upgrade_after_activation(node_id=2)
        self.test_witness_sigops()


if __name__ == '__main__':
    SegWitTest().main()