Merge #10952: [wallet] Remove vchDefaultKey and have better first run detection

e53615b Remove vchDefaultKey and have better first run detection (Andrew Chow)

Pull request description:

  Removes vchDefaultKey which was only used for first run detection. Improves wallet first run detection by checking to see if any keys were read from the database.

  This also fixes a (rather contrived) case where an encrypted non-HD wallet has corruption such that the default key is no longer valid and is loaded into a Core version that supports HD wallets. This causes a runtime exception since a new hd master key is generated as the software believes the wallet file is newly created but cannot add the generated key to the wallet since it is encrypted. I was only able to replicate this error by creating a non-hd wallet, encrypting it, then editing the wallet using `db_dump` and `db_load` before loading the wallet with hd enabled. This problem has been reported by [two](https://bitcointalk.org/index.php?topic=1993244.0) [users](https://bitcointalk.org/index.php?topic=1746976.msg17511261#msg17511261) so it is something that can happen, although that raises the question of "what corrupted the default key".

  ~P.S. I don't know what's up with the whitespace changes. I think my text editor is doing something stupid but I don't think those are important enough to attempt undoing them.~ Undid those

Tree-SHA512: 63b485f356566e8ffa033ad9b7101f7f6b56372b29ec2a43b947b0eeb1ada4c2cfe24740515d013aedd5f51aa1890dfbe499d2c5c062fc1b5d272324728a7d55

5 files changed, 18 insertions, 33 deletions

diff --git a/src/wallet/crypter.h b/src/wallet/crypter.h
index 1dc44e424f..f1e8a25650 100644
--- a/src/wallet/crypter.h
+++ b/src/wallet/crypter.h
@@ -113,7 +113,6 @@ public:
 class CCryptoKeyStore : public CBasicKeyStore
 {
 private:
-    CryptedKeyMap mapCryptedKeys;
 
     CKeyingMaterial vMasterKey;
 
@@ -131,6 +130,7 @@ protected:
     bool EncryptKeys(CKeyingMaterial& vMasterKeyIn);
 
     bool Unlock(const CKeyingMaterial& vMasterKeyIn);
+    CryptedKeyMap mapCryptedKeys;
 
 public:
     CCryptoKeyStore() : fUseCrypto(false), fDecryptionThoroughlyChecked(false)
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 10c834cb33..c32726aeb0 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -3123,9 +3123,11 @@ DBErrors CWallet::LoadWallet(bool& fFirstRunRet)
         }
     }
 
+    // This wallet is in its first run if all of these are empty
+    fFirstRunRet = mapKeys.empty() && mapCryptedKeys.empty() && mapWatchKeys.empty() && setWatchOnly.empty() && mapScripts.empty();
+
     if (nLoadWalletRet != DB_LOAD_OK)
         return nLoadWalletRet;
-    fFirstRunRet = !vchDefaultKey.IsValid();
 
     uiInterface.LoadWallet(this);
 
@@ -3135,7 +3137,6 @@ DBErrors CWallet::LoadWallet(bool& fFirstRunRet)
 DBErrors CWallet::ZapSelectTx(std::vector<uint256>& vHashIn, std::vector<uint256>& vHashOut)
 {
     AssertLockHeld(cs_wallet); // mapWallet
-    vchDefaultKey = CPubKey();
     DBErrors nZapSelectTxRet = CWalletDB(*dbw,"cr+").ZapSelectTx(vHashIn, vHashOut);
     for (uint256 hash : vHashOut)
         mapWallet.erase(hash);
@@ -3164,7 +3165,6 @@ DBErrors CWallet::ZapSelectTx(std::vector<uint256>& vHashIn, std::vector<uint256
 
 DBErrors CWallet::ZapWalletTx(std::vector<CWalletTx>& vWtx)
 {
-    vchDefaultKey = CPubKey();
     DBErrors nZapWalletTxRet = CWalletDB(*dbw,"cr+").ZapWalletTx(vWtx);
     if (nZapWalletTxRet == DB_NEED_REWRITE)
     {
@@ -3240,14 +3240,6 @@ const std::string& CWallet::GetAccountName(const CScript& scriptPubKey) const
     return DEFAULT_ACCOUNT_NAME;
 }
 
-bool CWallet::SetDefaultKey(const CPubKey &vchPubKey)
-{
-    if (!CWalletDB(*dbw).WriteDefaultKey(vchPubKey))
-        return false;
-    vchDefaultKey = vchPubKey;
-    return true;
-}
-
 /**
  * Mark old keypool keys as used,
  * and generate all new keys
@@ -4019,13 +4011,11 @@ CWallet* CWallet::CreateWalletFromFile(const std::string walletFile)
             if (!walletInstance->SetHDMasterKey(masterPubKey))
                 throw std::runtime_error(std::string(__func__) + ": Storing master key failed");
         }
-        CPubKey newDefaultKey;
-        if (walletInstance->GetKeyFromPool(newDefaultKey, false)) {
-            walletInstance->SetDefaultKey(newDefaultKey);
-            if (!walletInstance->SetAddressBook(walletInstance->vchDefaultKey.GetID(), "", "receive")) {
-                InitError(_("Cannot write default address") += "\n");
-                return nullptr;
-            }
+
+        // Top up the keypool
+        if (!walletInstance->TopUpKeyPool()) {
+            InitError(_("Unable to generate initial keys") += "\n");
+            return NULL;
         }
 
         walletInstance->SetBestChain(chainActive.GetLocator());
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 48a25666f7..0d2cb2e29d 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -807,8 +807,6 @@ public:
 
     std::map<CTxDestination, CAddressBookData> mapAddressBook;
 
-    CPubKey vchDefaultKey;
-
     std::set<COutPoint> setLockedCoins;
 
     const CWalletTx* GetWalletTx(const uint256& hash) const;
@@ -1038,8 +1036,6 @@ public:
         return setInternalKeyPool.size() + setExternalKeyPool.size();
     }
 
-    bool SetDefaultKey(const CPubKey &vchPubKey);
-
     //! signify that a particular wallet feature is now used. this may change nWalletVersion and nWalletMaxVersion if those are lower
     bool SetMinVersion(enum WalletFeature, CWalletDB* pwalletdbIn = nullptr, bool fExplicit = false);
 
diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index cd26d87fdb..12da3cce64 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -130,11 +130,6 @@ bool CWalletDB::WriteOrderPosNext(int64_t nOrderPosNext)
     return WriteIC(std::string("orderposnext"), nOrderPosNext);
 }
 
-bool CWalletDB::WriteDefaultKey(const CPubKey& vchPubKey)
-{
-    return WriteIC(std::string("defaultkey"), vchPubKey);
-}
-
 bool CWalletDB::ReadPool(int64_t nPool, CKeyPool& keypool)
 {
     return batch.Read(std::make_pair(std::string("pool"), nPool), keypool);
@@ -452,7 +447,14 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
         }
         else if (strType == "defaultkey")
         {
-            ssValue >> pwallet->vchDefaultKey;
+            // We don't want or need the default key, but if there is one set,
+            // we want to make sure that it is valid so that we can detect corruption
+            CPubKey vchPubKey;
+            ssValue >> vchPubKey;
+            if (!vchPubKey.IsValid()) {
+                strErr = "Error reading wallet database: Default Key corrupt";
+                return false;
+            }
         }
         else if (strType == "pool")
         {
@@ -522,7 +524,6 @@ bool CWalletDB::IsKeyType(const std::string& strType)
 
 DBErrors CWalletDB::LoadWallet(CWallet* pwallet)
 {
-    pwallet->vchDefaultKey = CPubKey();
     CWalletScanState wss;
     bool fNoncriticalErrors = false;
     DBErrors result = DB_LOAD_OK;
@@ -565,7 +566,7 @@ DBErrors CWalletDB::LoadWallet(CWallet* pwallet)
             {
                 // losing keys is considered a catastrophic error, anything else
                 // we assume the user can live with:
-                if (IsKeyType(strType))
+                if (IsKeyType(strType) || strType == "defaultkey")
                     result = DB_CORRUPT;
                 else
                 {
diff --git a/src/wallet/walletdb.h b/src/wallet/walletdb.h
index e4857f6cab..4f8ea185d5 100644
--- a/src/wallet/walletdb.h
+++ b/src/wallet/walletdb.h
@@ -191,8 +191,6 @@ public:
 
     bool WriteOrderPosNext(int64_t nOrderPosNext);
 
-    bool WriteDefaultKey(const CPubKey& vchPubKey);
-
     bool ReadPool(int64_t nPool, CKeyPool& keypool);
     bool WritePool(int64_t nPool, const CKeyPool& keypool);
     bool ErasePool(int64_t nPool);