Disallow bech32m addresses for legacy wallet things

We don't want the legacy wallet to ever have bech32m addresses so don't
allow importing them. This includes addmultisigaddress as that is a
legacy wallet only RPC

Additionally, bech32m multisigs are not available yet, so disallow them
in createmultisig.

7 files changed, 45 insertions, 16 deletions

diff --git a/src/outputtype.cpp b/src/outputtype.cpp
index 9748fe24c7..8ede7b9974 100644
--- a/src/outputtype.cpp
+++ b/src/outputtype.cpp
@@ -108,3 +108,19 @@ CTxDestination AddAndGetDestinationForScript(FillableSigningProvider& keystore,
     } // no default case, so the compiler can warn about missing cases
     assert(false);
 }
+
+std::optional<OutputType> OutputTypeFromDestination(const CTxDestination& dest) {
+    if (std::holds_alternative<PKHash>(dest) ||
+        std::holds_alternative<ScriptHash>(dest)) {
+        return OutputType::LEGACY;
+    }
+    if (std::holds_alternative<WitnessV0KeyHash>(dest) ||
+        std::holds_alternative<WitnessV0ScriptHash>(dest)) {
+        return OutputType::BECH32;
+    }
+    if (std::holds_alternative<WitnessV1Taproot>(dest) ||
+        std::holds_alternative<WitnessUnknown>(dest)) {
+        return OutputType::BECH32M;
+    }
+    return std::nullopt;
+}
diff --git a/src/outputtype.h b/src/outputtype.h
index 8727d3f543..2b83235cd0 100644
--- a/src/outputtype.h
+++ b/src/outputtype.h
@@ -47,4 +47,7 @@ std::vector<CTxDestination> GetAllDestinationsForKey(const CPubKey& key);
  */
 CTxDestination AddAndGetDestinationForScript(FillableSigningProvider& keystore, const CScript& script, OutputType);
 
+/** Get the OutputType for a CTxDestination */
+std::optional<OutputType> OutputTypeFromDestination(const CTxDestination& dest);
+
 #endif // BITCOIN_OUTPUTTYPE_H
diff --git a/src/rpc/misc.cpp b/src/rpc/misc.cpp
index ab239fe79c..5178ce60e8 100644
--- a/src/rpc/misc.cpp
+++ b/src/rpc/misc.cpp
@@ -131,6 +131,9 @@ static RPCHelpMan createmultisig()
         if (!ParseOutputType(request.params[2].get_str(), output_type)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Unknown address type '%s'", request.params[2].get_str()));
         }
+        if (output_type == OutputType::BECH32M) {
+            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "createmultisig cannot create bech32m multisig addresses");
+        }
     }
 
     // Construct using pay-to-script-hash:
diff --git a/src/script/descriptor.cpp b/src/script/descriptor.cpp
index 5da249b7f9..d796ed26aa 100644
--- a/src/script/descriptor.cpp
+++ b/src/script/descriptor.cpp
@@ -640,22 +640,6 @@ public:
     std::optional<OutputType> GetOutputType() const override { return std::nullopt; }
 };
 
-static std::optional<OutputType> OutputTypeFromDestination(const CTxDestination& dest) {
-    if (std::holds_alternative<PKHash>(dest) ||
-        std::holds_alternative<ScriptHash>(dest)) {
-        return OutputType::LEGACY;
-    }
-    if (std::holds_alternative<WitnessV0KeyHash>(dest) ||
-        std::holds_alternative<WitnessV0ScriptHash>(dest)) {
-        return OutputType::BECH32;
-    }
-    if (std::holds_alternative<WitnessV1Taproot>(dest) ||
-        std::holds_alternative<WitnessUnknown>(dest)) {
-        return OutputType::BECH32M;
-    }
-    return std::nullopt;
-}
-
 /** A parsed addr(A) descriptor. */
 class AddressDescriptor final : public DescriptorImpl
 {
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 4e9ba83ead..35649ab02c 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -286,6 +286,9 @@ RPCHelpMan importaddress()
             if (fP2SH) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Cannot use the p2sh flag with an address - use a script instead");
             }
+            if (OutputTypeFromDestination(dest) == OutputType::BECH32M) {
+                throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Bech32m addresses cannot be imported into legacy wallets");
+            }
 
             pwallet->MarkDirty();
 
@@ -962,6 +965,9 @@ static UniValue ProcessImportLegacy(ImportData& import_data, std::map<CKeyID, CP
         if (!IsValidDestination(dest)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid address \"" + output + "\"");
         }
+        if (OutputTypeFromDestination(dest) == OutputType::BECH32M) {
+            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Bech32m addresses cannot be imported into legacy wallets");
+        }
         script = GetScriptForDestination(dest);
     } else {
         if (!IsHex(output)) {
@@ -1086,6 +1092,9 @@ static UniValue ProcessImportDescriptor(ImportData& import_data, std::map<CKeyID
     if (!parsed_desc) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, error);
     }
+    if (parsed_desc->GetOutputType() == OutputType::BECH32M) {
+        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Bech32m descriptors cannot be imported into legacy wallets");
+    }
 
     have_solving_data = parsed_desc->IsSolvable();
     const bool watch_only = data.exists("watchonly") ? data["watchonly"].get_bool() : false;
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 8b1b6c6d95..951f575c2f 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -269,6 +269,9 @@ static RPCHelpMan getnewaddress()
         if (!ParseOutputType(request.params[1].get_str(), output_type)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Unknown address type '%s'", request.params[1].get_str()));
         }
+        if (output_type == OutputType::BECH32M && pwallet->GetLegacyScriptPubKeyMan()) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Legacy wallets cannot provide bech32m addresses");
+        }
     }
 
     CTxDestination dest;
@@ -313,6 +316,9 @@ static RPCHelpMan getrawchangeaddress()
         if (!ParseOutputType(request.params[0].get_str(), output_type)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Unknown address type '%s'", request.params[0].get_str()));
         }
+        if (output_type == OutputType::BECH32M && pwallet->GetLegacyScriptPubKeyMan()) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Legacy wallets cannot provide bech32m addresses");
+        }
     }
 
     CTxDestination dest;
@@ -1004,6 +1010,9 @@ static RPCHelpMan addmultisigaddress()
         if (!ParseOutputType(request.params[3].get_str(), output_type)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Unknown address type '%s'", request.params[3].get_str()));
         }
+        if (output_type == OutputType::BECH32M) {
+            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Bech32m multisig addresses cannot be created with legacy wallets");
+        }
     }
 
     // Construct using pay-to-script-hash:
diff --git a/src/wallet/scriptpubkeyman.cpp b/src/wallet/scriptpubkeyman.cpp
index dedd40694e..2f7729a901 100644
--- a/src/wallet/scriptpubkeyman.cpp
+++ b/src/wallet/scriptpubkeyman.cpp
@@ -26,6 +26,7 @@ bool LegacyScriptPubKeyMan::GetNewDestination(const OutputType type, CTxDestinat
         error = _("Error: Legacy wallets only support the \"legacy\", \"p2sh-segwit\", and \"bech32\" address types").translated;
         return false;
     }
+    assert(type != OutputType::BECH32M);
 
     LOCK(cs_KeyStore);
     error.clear();
@@ -299,6 +300,7 @@ bool LegacyScriptPubKeyMan::GetReservedDestination(const OutputType type, bool i
     if (LEGACY_OUTPUT_TYPES.count(type) == 0) {
         return false;
     }
+    assert(type != OutputType::BECH32M);
 
     LOCK(cs_KeyStore);
     if (!CanGetAddresses(internal)) {
@@ -1303,6 +1305,7 @@ void LegacyScriptPubKeyMan::AddKeypoolPubkeyWithDB(const CPubKey& pubkey, const
 
 void LegacyScriptPubKeyMan::KeepDestination(int64_t nIndex, const OutputType& type)
 {
+    assert(type != OutputType::BECH32M);
     // Remove from key pool
     WalletBatch batch(m_storage.GetDatabase());
     batch.ErasePool(nIndex);
@@ -1336,6 +1339,7 @@ void LegacyScriptPubKeyMan::ReturnDestination(int64_t nIndex, bool fInternal, co
 
 bool LegacyScriptPubKeyMan::GetKeyFromPool(CPubKey& result, const OutputType type, bool internal)
 {
+    assert(type != OutputType::BECH32M);
     if (!CanGetAddresses(internal)) {
         return false;
     }
@@ -1404,6 +1408,7 @@ bool LegacyScriptPubKeyMan::ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& key
 
 void LegacyScriptPubKeyMan::LearnRelatedScripts(const CPubKey& key, OutputType type)
 {
+    assert(type != OutputType::BECH32M);
     if (key.IsCompressed() && (type == OutputType::P2SH_SEGWIT || type == OutputType::BECH32)) {
         CTxDestination witdest = WitnessV0KeyHash(key.GetID());
         CScript witprog = GetScriptForDestination(witdest);