Merge #10788: [RPC] Fix addwitnessaddress by replacing ismine with producesignature

e222dc2 Replace ismine with producesignature check in witnessifier (Andrew Chow)

Pull request description:

  Instead of using ismine to check whether an address can be spent by us, make the witness version of the script or address first and then use ProduceSignature with the DummySignatureCreator to check if we can
  solve for the script.

  This is to fix cases where we don't have all of the private keys (for something like a multisig address) but have the redeemscript so we can witnessify it.

Tree-SHA512: 371777aee839cceb41f099109a13689120d35cf3880cde39216596cc2aac5cc1096af7d9cf07ad9306c3b05c073897f4518a7e97f0b88642f1e3b80b799f481e

1 files changed, 16 insertions, 8 deletions

diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 14560860cb..a7c229fa74 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -1130,11 +1130,15 @@ public:
     bool operator()(const CKeyID &keyID) {
         if (pwallet) {
             CScript basescript = GetScriptForDestination(keyID);
-            isminetype typ;
-            typ = IsMine(*pwallet, basescript, SIGVERSION_WITNESS_V0);
-            if (typ != ISMINE_SPENDABLE && typ != ISMINE_WATCH_SOLVABLE)
-                return false;
             CScript witscript = GetScriptForWitness(basescript);
+            SignatureData sigs;
+            // This check is to make sure that the script we created can actually be solved for and signed by us
+            // if we were to have the private keys. This is just to make sure that the script is valid and that,
+            // if found in a transaction, we would still accept and relay that transcation.
+            if (!ProduceSignature(DummySignatureCreator(pwallet), witscript, sigs) ||
+                !VerifyScript(sigs.scriptSig, witscript, &sigs.scriptWitness, MANDATORY_SCRIPT_VERIFY_FLAGS | SCRIPT_VERIFY_WITNESS_PUBKEYTYPE, DummySignatureCreator(pwallet).Checker())) {
+                return false;
+            }
             pwallet->AddCScript(witscript);
             result = CScriptID(witscript);
             return true;
@@ -1151,11 +1155,15 @@ public:
                 result = scriptID;
                 return true;
             }
-            isminetype typ;
-            typ = IsMine(*pwallet, subscript, SIGVERSION_WITNESS_V0);
-            if (typ != ISMINE_SPENDABLE && typ != ISMINE_WATCH_SOLVABLE)
-                return false;
             CScript witscript = GetScriptForWitness(subscript);
+            SignatureData sigs;
+            // This check is to make sure that the script we created can actually be solved for and signed by us
+            // if we were to have the private keys. This is just to make sure that the script is valid and that,
+            // if found in a transaction, we would still accept and relay that transcation.
+            if (!ProduceSignature(DummySignatureCreator(pwallet), witscript, sigs) ||
+                !VerifyScript(sigs.scriptSig, witscript, &sigs.scriptWitness, MANDATORY_SCRIPT_VERIFY_FLAGS | SCRIPT_VERIFY_WITNESS_PUBKEYTYPE, DummySignatureCreator(pwallet).Checker())) {
+                return false;
+            }
             pwallet->AddCScript(witscript);
             result = CScriptID(witscript);
             return true;