Merge #16026: Ensure that uncompressed public keys in a multisig always returns a legacy address

a49503402b6bc21e3878e151c07529941d36aed0 Make and get the multisig redeemscript and destination in one function instead of two (Andrew Chow)

Pull request description:

  `CreateMultisigRedeemscript()` is changed to `AddAndGetMultisigDestination()` so that the process of constructing the redeemScript and then getting the `CTxDestination` are done in the same function. This allows that function to see what the keys in the multisig are so that the correct address type is returned from `AddAndGetDestinationForScript()`.

  This only effects the `createmultisig` and `addmultisigaddress` RPCs and does not change signing logic as #16022 does.

  Alternative to #16022 and #16012

  Fixes #16011

ACKs for commit a49503:

Tree-SHA512: 5b0154a714deea3b2cc3a54beb420c95eeeacf4ca30c40ca80940d9d640f8b03611b0fc14c2f0710bfd8a79e8d27ad7d9ae380b4b83d52b40ab201624f2a63f0

1 files changed, 29 insertions, 1 deletions

diff --git a/test/functional/rpc_createmultisig.py b/test/functional/rpc_createmultisig.py
index 7abcd71bb8..58010f7c2e 100755
--- a/test/functional/rpc_createmultisig.py
+++ b/test/functional/rpc_createmultisig.py
@@ -7,9 +7,13 @@
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_raises_rpc_error,
+    assert_equal,
 )
-import decimal
+from test_framework.key import ECPubKey
 
+import binascii
+import decimal
+import itertools
 
 class RpcCreateMultiSigTest(BitcoinTestFramework):
     def set_test_params(self):
@@ -44,6 +48,30 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
 
         self.checkbalances()
 
+        # Test mixed compressed and uncompressed pubkeys
+        self.log.info('Mixed compressed and uncompressed multisigs are not allowed')
+        pk0 = node0.getaddressinfo(node0.getnewaddress())['pubkey']
+        pk1 = node1.getaddressinfo(node1.getnewaddress())['pubkey']
+        pk2 = node2.getaddressinfo(node2.getnewaddress())['pubkey']
+
+        # decompress pk2
+        pk_obj = ECPubKey()
+        pk_obj.set(binascii.unhexlify(pk2))
+        pk_obj.compressed = False
+        pk2 = binascii.hexlify(pk_obj.get_bytes()).decode()
+
+        # 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'])
+
+            # 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'])
+
     def check_addmultisigaddress_errors(self):
         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)]