Add a --descriptors option to various tests

Adds a --descriptors option globally to the test framework. This will
make the test create and use descriptor wallets. However some tests may
not work with this.

Some tests are modified to work with --descriptors and run with that
option in test_runer:
* wallet_basic.py
* wallet_encryption.py
* wallet_keypool.py
* wallet_keypool_topup.py
* wallet_labels.py
* wallet_avoidreuse.py

test/functional/rpc_createmultisig.py

@@ -4,13 +4,14 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Test multisig RPCs"""
 
+from test_framework.authproxy import JSONRPCException
 from test_framework.descriptors import descsum_create, drop_origins
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_raises_rpc_error,
     assert_equal,
 )
-from test_framework.key import ECPubKey
+from test_framework.key import ECPubKey, ECKey, bytes_to_wif
 
 import binascii
 import decimal
@@ -28,10 +29,14 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
         self.skip_if_no_wallet()
 
     def get_keys(self):
+        self.pub = []
+        self.priv = []
         node0, node1, node2 = self.nodes
-        add = [node1.getnewaddress() for _ in range(self.nkeys)]
-        self.pub = [node1.getaddressinfo(a)["pubkey"] for a in add]
-        self.priv = [node1.dumpprivkey(a) for a in add]
+        for _ in range(self.nkeys):
+            k = ECKey()
+            k.generate()
+            self.pub.append(k.get_pubkey().get_bytes().hex())
+            self.priv.append(bytes_to_wif(k.get_bytes(), k.is_compressed))
         self.final = node2.getnewaddress()
 
     def run_test(self):
@@ -64,17 +69,20 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
         pk_obj.compressed = False
         pk2 = binascii.hexlify(pk_obj.get_bytes()).decode()
 
+        node0.createwallet(wallet_name='wmulti0', disable_private_keys=True)
+        wmulti0 = node0.get_wallet_rpc('wmulti0')
+
         # Check all permutations of keys because order matters apparently
         for keys in itertools.permutations([pk0, pk1, pk2]):
             # Results should be the same as this legacy one
             legacy_addr = node0.createmultisig(2, keys, 'legacy')['address']
-            assert_equal(legacy_addr, node0.addmultisigaddress(2, keys, '', 'legacy')['address'])
+            assert_equal(legacy_addr, wmulti0.addmultisigaddress(2, keys, '', 'legacy')['address'])
 
             # Generate addresses with the segwit types. These should all make legacy addresses
-            assert_equal(legacy_addr, node0.createmultisig(2, keys, 'bech32')['address'])
-            assert_equal(legacy_addr, node0.createmultisig(2, keys, 'p2sh-segwit')['address'])
-            assert_equal(legacy_addr, node0.addmultisigaddress(2, keys, '', 'bech32')['address'])
-            assert_equal(legacy_addr, node0.addmultisigaddress(2, keys, '', 'p2sh-segwit')['address'])
+            assert_equal(legacy_addr, wmulti0.createmultisig(2, keys, 'bech32')['address'])
+            assert_equal(legacy_addr, wmulti0.createmultisig(2, keys, 'p2sh-segwit')['address'])
+            assert_equal(legacy_addr, wmulti0.addmultisigaddress(2, keys, '', 'bech32')['address'])
+            assert_equal(legacy_addr, wmulti0.addmultisigaddress(2, keys, '', 'p2sh-segwit')['address'])
 
         self.log.info('Testing sortedmulti descriptors with BIP 67 test vectors')
         with open(os.path.join(os.path.dirname(os.path.realpath(__file__)), 'data/rpc_bip67.json'), encoding='utf-8') as f:
@@ -89,6 +97,8 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
             assert_equal(self.nodes[0].deriveaddresses(sorted_key_desc)[0], t['address'])
 
     def check_addmultisigaddress_errors(self):
+        if self.options.descriptors:
+            return
         self.log.info('Check that addmultisigaddress fails when the private keys are missing')
         addresses = [self.nodes[1].getnewaddress(address_type='legacy') for _ in range(2)]
         assert_raises_rpc_error(-5, 'no full public key for address', lambda: self.nodes[0].addmultisigaddress(nrequired=1, keys=addresses))
@@ -115,6 +125,15 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
 
     def do_multisig(self):
         node0, node1, node2 = self.nodes
+        if 'wmulti' not in node1.listwallets():
+            try:
+                node1.loadwallet('wmulti')
+            except JSONRPCException as e:
+                if e.error['code'] == -18 and 'Wallet wmulti not found' in e.error['message']:
+                    node1.createwallet(wallet_name='wmulti', disable_private_keys=True)
+                else:
+                    raise
+        wmulti = node1.get_wallet_rpc('wmulti')
 
         # Construct the expected descriptor
         desc = 'multi({},{})'.format(self.nsigs, ','.join(self.pub))
@@ -134,7 +153,7 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
             assert madd[0:4] == "bcrt"  # actually a bech32 address
 
         # compare against addmultisigaddress
-        msigw = node1.addmultisigaddress(self.nsigs, self.pub, None, self.output_type)
+        msigw = wmulti.addmultisigaddress(self.nsigs, self.pub, None, self.output_type)
         maddw = msigw["address"]
         mredeemw = msigw["redeemScript"]
         assert_equal(desc, drop_origins(msigw['descriptor']))
@@ -194,6 +213,8 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
         txinfo = node0.getrawtransaction(tx, True, blk)
         self.log.info("n/m=%d/%d %s size=%d vsize=%d weight=%d" % (self.nsigs, self.nkeys, self.output_type, txinfo["size"], txinfo["vsize"], txinfo["weight"]))
 
+        wmulti.unloadwallet()
+
 
 if __name__ == '__main__':
     RpcCreateMultiSigTest().main()