Merge #17621: IsUsedDestination should count any known single-key address

09502452bbbe21bb974f1de8cf53196373921ab9 IsUsedDestination should count any known single-key address (Gregory Sanders)

Pull request description:

  This plugs the privacy leak detailed at https://github.com/bitcoin/bitcoin/issues/17605, at least for the single-key case.

ACKs for top commit:
  meshcollider:
    Code Review ACK 09502452bbbe21bb974f1de8cf53196373921ab9

Tree-SHA512: e1d68281675f05072b3087171cba1df9416a69c9ccf70c72e8555e55eadda2d0fd339e5a894e3a3438ff94b9e3827fb19b8b701faade70c08756b19ff157ee0c

1 files changed, 21 insertions, 4 deletions

diff --git a/test/functional/wallet_avoidreuse.py b/test/functional/wallet_avoidreuse.py
index 3cfb5a648b..0ca8c80956 100755
--- a/test/functional/wallet_avoidreuse.py
+++ b/test/functional/wallet_avoidreuse.py
@@ -86,7 +86,12 @@ class AvoidReuseTest(BitcoinTestFramework):
         reset_balance(self.nodes[1], self.nodes[0].getnewaddress())
         self.test_fund_send_fund_senddirty()
         reset_balance(self.nodes[1], self.nodes[0].getnewaddress())
-        self.test_fund_send_fund_send()
+        self.test_fund_send_fund_send("legacy")
+        reset_balance(self.nodes[1], self.nodes[0].getnewaddress())
+        self.test_fund_send_fund_send("p2sh-segwit")
+        reset_balance(self.nodes[1], self.nodes[0].getnewaddress())
+        self.test_fund_send_fund_send("bech32")
+
 
     def test_persistence(self):
         '''Test that wallet files persist the avoid_reuse flag.'''
@@ -182,7 +187,7 @@ class AvoidReuseTest(BitcoinTestFramework):
         assert_approx(self.nodes[1].getbalance(), 5, 0.001)
         assert_approx(self.nodes[1].getbalance(avoid_reuse=False), 5, 0.001)
 
-    def test_fund_send_fund_send(self):
+    def test_fund_send_fund_send(self, second_addr_type):
         '''
         Test the simple case where [1] generates a new address A, then
         [0] sends 10 BTC to A.
@@ -193,7 +198,7 @@ class AvoidReuseTest(BitcoinTestFramework):
         '''
         self.log.info("Test fund send fund send")
 
-        fundaddr = self.nodes[1].getnewaddress()
+        fundaddr = self.nodes[1].getnewaddress(label="", address_type="legacy")
         retaddr = self.nodes[0].getnewaddress()
 
         self.nodes[0].sendtoaddress(fundaddr, 10)
@@ -214,7 +219,19 @@ class AvoidReuseTest(BitcoinTestFramework):
         # getbalances should show no used, 5 btc trusted
         assert_balances(self.nodes[1], mine={"used": 0, "trusted": 5})
 
-        self.nodes[0].sendtoaddress(fundaddr, 10)
+        # For the second send, we transmute it to a related single-key address
+        # to make sure it's also detected as re-use
+        fund_spk = self.nodes[0].getaddressinfo(fundaddr)["scriptPubKey"]
+        fund_decoded = self.nodes[0].decodescript(fund_spk)
+        if second_addr_type == "p2sh-segwit":
+            new_fundaddr = fund_decoded["segwit"]["p2sh-segwit"]
+        elif second_addr_type == "bech32":
+            new_fundaddr = fund_decoded["segwit"]["addresses"][0]
+        else:
+            new_fundaddr = fundaddr
+            assert_equal(second_addr_type, "legacy")
+
+        self.nodes[0].sendtoaddress(new_fundaddr, 10)
         self.nodes[0].generate(1)
         self.sync_all()