Merge bitcoin/bitcoin#23113: Add warnings to createmultisig and addmultisig if using uncompressed keys

d5cab1a96d26e66d342fb5ec35c809bb82869d00 Add createmultisig and addmultisigaddress warnings release note (Samuel Dobson)
e46fc935aa6eb392ef9411dad310697aba601f6a Add warnings field to addmultisigaddress to warn about uncompressed keys (Samuel Dobson)
d1a9742623e2a8f3307c84c2df6993f62617a6f6 Add warnings field to createmultisig to warn about uncompressed keys (Samuel Dobson)

Pull request description:

  Fixes #21368

  Currently, if there are any uncompressed keys when calling `AddAndGetMultisigDestination`, it will just default to a legacy address regardless of the chosen `address_type`. Rather than keeping this silent behaviour which may be confusing to users, we explicitly add a `warnings` field which will warn the user why their address format is different.

ACKs for top commit:
  achow101:
    ACK d5cab1a96d26e66d342fb5ec35c809bb82869d00

Tree-SHA512: c2ac7f7689251bd4fcd8c26506f053921fbaf34c7a26a74e82ebc7f82cc0bd25407fd7954bf98365dcafa51fa45dcdbee6214320580ca69509690c3555e71cc0

4 files changed, 43 insertions, 5 deletions

diff --git a/doc/release-notes-23113.md b/doc/release-notes-23113.md
new file mode 100644
index 0000000000..b0904c9d7b
--- /dev/null
+++ b/doc/release-notes-23113.md
@@ -0,0 +1,9 @@
+Notable changes
+===============
+
+Updated RPCs
+------------
+
+- Both `createmultisig` and `addmultisigaddress` now include a `warnings`
+field, which will show a warning if a non-legacy address type is requested
+when using uncompressed public keys.
diff --git a/src/rpc/misc.cpp b/src/rpc/misc.cpp
index a5ee538f67..2761c69167 100644
--- a/src/rpc/misc.cpp
+++ b/src/rpc/misc.cpp
@@ -114,6 +114,10 @@ static RPCHelpMan createmultisig()
                         {RPCResult::Type::STR, "address", "The value of the new multisig address."},
                         {RPCResult::Type::STR_HEX, "redeemScript", "The string value of the hex-encoded redemption script."},
                         {RPCResult::Type::STR, "descriptor", "The descriptor for this multisig"},
+                        {RPCResult::Type::ARR, "warnings", /* optional */ true, "Any warnings resulting from the creation of this multisig",
+                        {
+                            {RPCResult::Type::STR, "", ""},
+                        }},
                     }
                 },
                 RPCExamples{
@@ -162,6 +166,13 @@ static RPCHelpMan createmultisig()
     result.pushKV("redeemScript", HexStr(inner));
     result.pushKV("descriptor", descriptor->ToString());
 
+    UniValue warnings(UniValue::VARR);
+    if (!request.params[2].isNull() && OutputTypeFromDestination(dest) != output_type) {
+        // Only warns if the user has explicitly chosen an address type we cannot generate
+        warnings.push_back("Unable to make chosen address type, please ensure no uncompressed public keys are present.");
+    }
+    if (warnings.size()) result.pushKV("warnings", warnings);
+
     return result;
 },
     };
diff --git a/src/wallet/rpc/addresses.cpp b/src/wallet/rpc/addresses.cpp
index e570c18099..c7400cafe7 100644
--- a/src/wallet/rpc/addresses.cpp
+++ b/src/wallet/rpc/addresses.cpp
@@ -238,6 +238,10 @@ RPCHelpMan addmultisigaddress()
                         {RPCResult::Type::STR, "address", "The value of the new multisig address"},
                         {RPCResult::Type::STR_HEX, "redeemScript", "The string value of the hex-encoded redemption script"},
                         {RPCResult::Type::STR, "descriptor", "The descriptor for this multisig"},
+                        {RPCResult::Type::ARR, "warnings", /* optional */ true, "Any warnings resulting from the creation of this multisig",
+                        {
+                            {RPCResult::Type::STR, "", ""},
+                        }},
                     }
                 },
                 RPCExamples{
@@ -295,6 +299,14 @@ RPCHelpMan addmultisigaddress()
     result.pushKV("address", EncodeDestination(dest));
     result.pushKV("redeemScript", HexStr(inner));
     result.pushKV("descriptor", descriptor->ToString());
+
+    UniValue warnings(UniValue::VARR);
+    if (!request.params[3].isNull() && OutputTypeFromDestination(dest) != output_type) {
+        // Only warns if the user has explicitly chosen an address type we cannot generate
+        warnings.push_back("Unable to make chosen address type, please ensure no uncompressed public keys are present.");
+    }
+    if (warnings.size()) result.pushKV("warnings", warnings);
+
     return result;
 },
     };
diff --git a/test/functional/rpc_createmultisig.py b/test/functional/rpc_createmultisig.py
index f56e71ae7a..1a3d14100f 100755
--- a/test/functional/rpc_createmultisig.py
+++ b/test/functional/rpc_createmultisig.py
@@ -75,13 +75,19 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
         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, wmulti0.addmultisigaddress(2, keys, '', 'legacy')['address'])
+            result = wmulti0.addmultisigaddress(2, keys, '', 'legacy')
+            assert_equal(legacy_addr, result['address'])
+            assert 'warnings' not in result
 
             # Generate addresses with the segwit types. These should all make legacy addresses
-            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'])
+            for addr_type in ['bech32', 'p2sh-segwit']:
+                result = wmulti0.createmultisig(2, keys, addr_type)
+                assert_equal(legacy_addr, result['address'])
+                assert_equal(result['warnings'], ["Unable to make chosen address type, please ensure no uncompressed public keys are present."])
+
+                result = wmulti0.addmultisigaddress(2, keys, '', addr_type)
+                assert_equal(legacy_addr, result['address'])
+                assert_equal(result['warnings'], ["Unable to make chosen address type, please ensure no uncompressed public keys are present."])
 
         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: