Merge #18192: Bugfix: Wallet: Safely deal with change in the address book

b5795a7 Wallet: Add warning comments and assert to CWallet::DelAddressBook (Luke Dashjr)
6d2905f Wallet: Avoid unnecessary/redundant m_address_book lookups (Luke Dashjr)
c751d88 Wallet: Avoid treating change-in-the-addressbook as non-change everywhere (Luke Dashjr)
8e64b8c Wallet: New FindAddressBookEntry method to filter out change entries (and skip ->second everywhere) (Luke Dashjr)
65b6bdc Wallet: Add CAddressBookData::IsChange which returns true iff label has never been set (Luke Dashjr)
144b2f8 Wallet: Require usage of new CAddressBookData::setLabel to change label (Luke Dashjr)
b86cd15 scripted-diff: Wallet: Rename mapAddressBook to m_address_book (Luke Dashjr)

Pull request description:

  In many places, our code assumes that presence in the address book indicates a non-change key, and absence of an entry in mapAddressBook indicates change.

  This no longer holds true after #13756 (first released in 0.19) since it added a "used" DestData populated even for change addresses. Only avoid-reuse wallets should be affected by this issue.

  Thankfully, populating DestData does not write a label to the database, so we can retroactively fix this (so long as the user didn't see the change address and manually assign it a real label).

  Fixing it is accomplished by:

  * Adding a new bool to CAddressBookData to track if the label has ever been assigned, either by loading one from the database, or by assigning one at runtime.
  * `CAddressBookData::IsChange` and `CWallet::FindAddressBookEntry` are new methods to assist in excluding change from code that doesn't expect to see them.
  * For safety in merging, `CAddressBookData::name` has been made read-only (the actual data is stored in `m_label`, a new private member, and can be changed only with `setLabel` which updates the `m_change` flag), and `mapAddressBook` has been renamed to `m_address_book` (to force old code to be rebased to compile).

  A final commit also does some minor optimisation, avoiding redundant lookups in `m_address_book` when we already have a pointer to the `CAddressBookData`.

ACKs for top commit:
  ryanofsky:
    Code review ACK b5795a7. Pretty clever and nicely implemented fix!
  jonatack:
    ACK b5795a7 nice improvements -- code review, built/ran tests rebased on current master ff53433 and tested manually with rpc/cli
  jnewbery:
    Good fix. utACK b5795a7.

Tree-SHA512: 40525185a0bcc1723f602243c269499ec86ecb298fecb5ef24d626bbdd5e3efece86cdb1084ad7eebf7eeaf251db4a6e056bcd25bc8457b417fcbb53d032ebf0

Author: MarcoFalke

src/interfaces/wallet.cpp

@@ -151,8 +151,8 @@ class WalletImpl : public Wallet
         std::string* purpose) override
     {
         LOCK(m_wallet->cs_wallet);
-        auto it = m_wallet->mapAddressBook.find(dest);
-        if (it == m_wallet->mapAddressBook.end()) {
+        auto it = m_wallet->m_address_book.find(dest);
+        if (it == m_wallet->m_address_book.end() || it->second.IsChange()) {
             return false;
         }
         if (name) {
@@ -170,7 +170,8 @@ class WalletImpl : public Wallet
     {
         LOCK(m_wallet->cs_wallet);
         std::vector<WalletAddress> result;
-        for (const auto& item : m_wallet->mapAddressBook) {
+        for (const auto& item : m_wallet->m_address_book) {
+            if (item.second.IsChange()) continue;
             result.emplace_back(item.first, m_wallet->IsMine(item.first), item.second.name, item.second.purpose);
         }
         return result;

src/qt/addresstablemodel.cpp

@@ -55,7 +55,7 @@ struct AddressTableEntryLessThan
 static AddressTableEntry::Type translateTransactionType(const QString &strPurpose, bool isMine)
 {
     AddressTableEntry::Type addressType = AddressTableEntry::Hidden;
-    // "refund" addresses aren't shown, and change addresses aren't in mapAddressBook at all.
+    // "refund" addresses aren't shown, and change addresses aren't returned by getAddresses at all.
     if (strPurpose == "send")
         addressType = AddressTableEntry::Sending;
     else if (strPurpose == "receive")

src/qt/test/addressbooktests.cpp

@@ -97,7 +97,7 @@ void TestAddAddressesToSendBook(interfaces::Node& node)
 
     auto check_addbook_size = [&wallet](int expected_size) {
         LOCK(wallet->cs_wallet);
-        QCOMPARE(static_cast<int>(wallet->mapAddressBook.size()), expected_size);
+        QCOMPARE(static_cast<int>(wallet->m_address_book.size()), expected_size);
     };
 
     // We should start with the two addresses we added earlier and nothing else.

src/wallet/rpcdump.cpp

@@ -60,12 +60,13 @@ static bool GetWalletAddressesForKey(LegacyScriptPubKeyMan* spk_man, const CWall
     CKey key;
     spk_man->GetKey(keyid, key);
     for (const auto& dest : GetAllDestinationsForKey(key.GetPubKey())) {
-        if (pwallet->mapAddressBook.count(dest)) {
+        const auto* address_book_entry = pwallet->FindAddressBookEntry(dest);
+        if (address_book_entry) {
             if (!strAddr.empty()) {
                 strAddr += ",";
             }
             strAddr += EncodeDestination(dest);
-            strLabel = EncodeDumpString(pwallet->mapAddressBook.at(dest).name);
+            strLabel = EncodeDumpString(address_book_entry->name);
             fLabelFound = true;
         }
     }
@@ -168,7 +169,7 @@ UniValue importprivkey(const JSONRPCRequest& request)
             // label all new addresses, and label existing addresses if a
             // label was passed.
             for (const auto& dest : GetAllDestinationsForKey(pubkey)) {
-                if (!request.params[1].isNull() || pwallet->mapAddressBook.count(dest) == 0) {
+                if (!request.params[1].isNull() || !pwallet->FindAddressBookEntry(dest)) {
                     pwallet->SetAddressBook(dest, strLabel, "receive");
                 }
             }

src/wallet/rpcwallet.cpp

@@ -499,8 +499,9 @@ static UniValue listaddressgroupings(const JSONRPCRequest& request)
             addressInfo.push_back(EncodeDestination(address));
             addressInfo.push_back(ValueFromAmount(balances[address]));
             {
-                if (pwallet->mapAddressBook.find(address) != pwallet->mapAddressBook.end()) {
-                    addressInfo.push_back(pwallet->mapAddressBook.find(address)->second.name);
+                const auto* address_book_entry = pwallet->FindAddressBookEntry(address);
+                if (address_book_entry) {
+                    addressInfo.push_back(address_book_entry->name);
                 }
             }
             jsonGrouping.push_back(addressInfo);
@@ -1092,20 +1093,21 @@ static UniValue ListReceived(interfaces::Chain::Lock& locked_chain, const CWalle
     UniValue ret(UniValue::VARR);
     std::map<std::string, tallyitem> label_tally;
 
-    // Create mapAddressBook iterator
+    // Create m_address_book iterator
     // If we aren't filtering, go from begin() to end()
-    auto start = pwallet->mapAddressBook.begin();
-    auto end = pwallet->mapAddressBook.end();
+    auto start = pwallet->m_address_book.begin();
+    auto end = pwallet->m_address_book.end();
     // If we are filtering, find() the applicable entry
     if (has_filtered_address) {
-        start = pwallet->mapAddressBook.find(filtered_address);
+        start = pwallet->m_address_book.find(filtered_address);
         if (start != end) {
             end = std::next(start);
         }
     }
 
     for (auto item_it = start; item_it != end; ++item_it)
     {
+        if (item_it->second.IsChange()) continue;
         const CTxDestination& address = item_it->first;
         const std::string& label = item_it->second.name;
         auto it = mapTally.find(address);
@@ -1307,8 +1309,9 @@ static void ListTransactions(interfaces::Chain::Lock& locked_chain, const CWalle
             MaybePushAddress(entry, s.destination);
             entry.pushKV("category", "send");
             entry.pushKV("amount", ValueFromAmount(-s.amount));
-            if (pwallet->mapAddressBook.count(s.destination)) {
-                entry.pushKV("label", pwallet->mapAddressBook.at(s.destination).name);
+            const auto* address_book_entry = pwallet->FindAddressBookEntry(s.destination);
+            if (address_book_entry) {
+                entry.pushKV("label", address_book_entry->name);
             }
             entry.pushKV("vout", s.vout);
             entry.pushKV("fee", ValueFromAmount(-nFee));
@@ -1324,8 +1327,9 @@ static void ListTransactions(interfaces::Chain::Lock& locked_chain, const CWalle
         for (const COutputEntry& r : listReceived)
         {
             std::string label;
-            if (pwallet->mapAddressBook.count(r.destination)) {
-                label = pwallet->mapAddressBook.at(r.destination).name;
+            const auto* address_book_entry = pwallet->FindAddressBookEntry(r.destination);
+            if (address_book_entry) {
+                label = address_book_entry->name;
             }
             if (filter_label && label != *filter_label) {
                 continue;
@@ -1349,7 +1353,7 @@ static void ListTransactions(interfaces::Chain::Lock& locked_chain, const CWalle
                 entry.pushKV("category", "receive");
             }
             entry.pushKV("amount", ValueFromAmount(r.amount));
-            if (pwallet->mapAddressBook.count(r.destination)) {
+            if (address_book_entry) {
                 entry.pushKV("label", label);
             }
             entry.pushKV("vout", r.vout);
@@ -2957,9 +2961,9 @@ static UniValue listunspent(const JSONRPCRequest& request)
         if (fValidAddress) {
             entry.pushKV("address", EncodeDestination(address));
 
-            auto i = pwallet->mapAddressBook.find(address);
-            if (i != pwallet->mapAddressBook.end()) {
-                entry.pushKV("label", i->second.name);
+            const auto* address_book_entry = pwallet->FindAddressBookEntry(address);
+            if (address_book_entry) {
+                entry.pushKV("label", address_book_entry->name);
             }
 
             std::unique_ptr<SigningProvider> provider = pwallet->GetSolvingProvider(scriptPubKey);
@@ -3816,8 +3820,9 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
     // DEPRECATED: Return label field if existing. Currently only one label can
     // be associated with an address, so the label should be equivalent to the
     // value of the name key/value pair in the labels array below.
-    if ((pwallet->chain().rpcEnableDeprecated("label")) && (pwallet->mapAddressBook.count(dest))) {
-        ret.pushKV("label", pwallet->mapAddressBook.at(dest).name);
+    const auto* address_book_entry = pwallet->FindAddressBookEntry(dest);
+    if (pwallet->chain().rpcEnableDeprecated("label") && address_book_entry) {
+        ret.pushKV("label", address_book_entry->name);
     }
 
     ret.pushKV("ischange", pwallet->IsChange(scriptPubKey));
@@ -3840,14 +3845,13 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
     // stable if we allow multiple labels to be associated with an address in
     // the future.
     UniValue labels(UniValue::VARR);
-    std::map<CTxDestination, CAddressBookData>::const_iterator mi = pwallet->mapAddressBook.find(dest);
-    if (mi != pwallet->mapAddressBook.end()) {
+    if (address_book_entry) {
         // DEPRECATED: The previous behavior of returning an array containing a
         // JSON object of `name` and `purpose` key/value pairs is deprecated.
         if (pwallet->chain().rpcEnableDeprecated("labelspurpose")) {
-            labels.push_back(AddressBookDataToJSON(mi->second, true));
+            labels.push_back(AddressBookDataToJSON(*address_book_entry, true));
         } else {
-            labels.push_back(mi->second.name);
+            labels.push_back(address_book_entry->name);
         }
     }
     ret.pushKV("labels", std::move(labels));
@@ -3891,10 +3895,11 @@ static UniValue getaddressesbylabel(const JSONRPCRequest& request)
     // Find all addresses that have the given label
     UniValue ret(UniValue::VOBJ);
     std::set<std::string> addresses;
-    for (const std::pair<const CTxDestination, CAddressBookData>& item : pwallet->mapAddressBook) {
+    for (const std::pair<const CTxDestination, CAddressBookData>& item : pwallet->m_address_book) {
+        if (item.second.IsChange()) continue;
         if (item.second.name == label) {
             std::string address = EncodeDestination(item.first);
-            // CWallet::mapAddressBook is not expected to contain duplicate
+            // CWallet::m_address_book is not expected to contain duplicate
             // address strings, but build a separate set as a precaution just in
             // case it does.
             bool unique = addresses.emplace(address).second;
@@ -3955,7 +3960,8 @@ static UniValue listlabels(const JSONRPCRequest& request)
 
     // Add to a set to sort by label name, then insert into Univalue array
     std::set<std::string> label_set;
-    for (const std::pair<const CTxDestination, CAddressBookData>& entry : pwallet->mapAddressBook) {
+    for (const std::pair<const CTxDestination, CAddressBookData>& entry : pwallet->m_address_book) {
+        if (entry.second.IsChange()) continue;
         if (purpose.empty() || entry.second.purpose == purpose) {
             label_set.insert(entry.second.name);
         }

src/wallet/wallet.cpp

@@ -1242,8 +1242,9 @@ bool CWallet::IsChange(const CScript& script) const
             return true;
 
         LOCK(cs_wallet);
-        if (!mapAddressBook.count(address))
+        if (!FindAddressBookEntry(address)) {
             return true;
+        }
     }
     return false;
 }
@@ -3196,11 +3197,11 @@ bool CWallet::SetAddressBookWithDB(WalletBatch& batch, const CTxDestination& add
     bool fUpdated = false;
     {
         LOCK(cs_wallet);
-        std::map<CTxDestination, CAddressBookData>::iterator mi = mapAddressBook.find(address);
-        fUpdated = mi != mapAddressBook.end();
-        mapAddressBook[address].name = strName;
+        std::map<CTxDestination, CAddressBookData>::iterator mi = m_address_book.find(address);
+        fUpdated = (mi != m_address_book.end() && !mi->second.IsChange());
+        m_address_book[address].SetLabel(strName);
         if (!strPurpose.empty()) /* update purpose only if requested */
-            mapAddressBook[address].purpose = strPurpose;
+            m_address_book[address].purpose = strPurpose;
     }
     NotifyAddressBookChanged(this, address, strName, IsMine(address) != ISMINE_NO,
                              strPurpose, (fUpdated ? CT_UPDATED : CT_NEW) );
@@ -3217,16 +3218,21 @@ bool CWallet::SetAddressBook(const CTxDestination& address, const std::string& s
 
 bool CWallet::DelAddressBook(const CTxDestination& address)
 {
+    // If we want to delete receiving addresses, we need to take care that DestData "used" (and possibly newer DestData) gets preserved (and the "deleted" address transformed into a change entry instead of actually being deleted)
+    // NOTE: This isn't a problem for sending addresses because they never have any DestData yet!
+    // When adding new DestData, it should be considered here whether to retain or delete it (or move it?).
+    assert(!IsMine(address));
+
     {
         LOCK(cs_wallet);
 
         // Delete destdata tuples associated with address
         std::string strAddress = EncodeDestination(address);
-        for (const std::pair<const std::string, std::string> &item : mapAddressBook[address].destdata)
+        for (const std::pair<const std::string, std::string> &item : m_address_book[address].destdata)
         {
             WalletBatch(*database).EraseDestData(strAddress, item.first);
         }
-        mapAddressBook.erase(address);
+        m_address_book.erase(address);
     }
 
     NotifyAddressBookChanged(this, address, "", IsMine(address) != ISMINE_NO, "", CT_DELETED);
@@ -3462,8 +3468,9 @@ std::set<CTxDestination> CWallet::GetLabelAddresses(const std::string& label) co
 {
     LOCK(cs_wallet);
     std::set<CTxDestination> result;
-    for (const std::pair<const CTxDestination, CAddressBookData>& item : mapAddressBook)
+    for (const std::pair<const CTxDestination, CAddressBookData>& item : m_address_book)
     {
+        if (item.second.IsChange()) continue;
         const CTxDestination& address = item.first;
         const std::string& strName = item.second.name;
         if (strName == label)
@@ -3666,26 +3673,26 @@ bool CWallet::AddDestData(WalletBatch& batch, const CTxDestination &dest, const
     if (boost::get<CNoDestination>(&dest))
         return false;
 
-    mapAddressBook[dest].destdata.insert(std::make_pair(key, value));
+    m_address_book[dest].destdata.insert(std::make_pair(key, value));
     return batch.WriteDestData(EncodeDestination(dest), key, value);
 }
 
 bool CWallet::EraseDestData(WalletBatch& batch, const CTxDestination &dest, const std::string &key)
 {
-    if (!mapAddressBook[dest].destdata.erase(key))
+    if (!m_address_book[dest].destdata.erase(key))
         return false;
     return batch.EraseDestData(EncodeDestination(dest), key);
 }
 
 void CWallet::LoadDestData(const CTxDestination &dest, const std::string &key, const std::string &value)
 {
-    mapAddressBook[dest].destdata.insert(std::make_pair(key, value));
+    m_address_book[dest].destdata.insert(std::make_pair(key, value));
 }
 
 bool CWallet::GetDestData(const CTxDestination &dest, const std::string &key, std::string *value) const
 {
-    std::map<CTxDestination, CAddressBookData>::const_iterator i = mapAddressBook.find(dest);
-    if(i != mapAddressBook.end())
+    std::map<CTxDestination, CAddressBookData>::const_iterator i = m_address_book.find(dest);
+    if(i != m_address_book.end())
     {
         CAddressBookData::StringMap::const_iterator j = i->second.destdata.find(key);
         if(j != i->second.destdata.end())
@@ -3701,7 +3708,7 @@ bool CWallet::GetDestData(const CTxDestination &dest, const std::string &key, st
 std::vector<std::string> CWallet::GetDestValues(const std::string& prefix) const
 {
     std::vector<std::string> values;
-    for (const auto& address : mapAddressBook) {
+    for (const auto& address : m_address_book) {
         for (const auto& data : address.second.destdata) {
             if (!data.first.compare(0, prefix.size(), prefix)) {
                 values.emplace_back(data.second);
@@ -4103,12 +4110,22 @@ std::shared_ptr<CWallet> CWallet::CreateWalletFromFile(interfaces::Chain& chain,
     {
         walletInstance->WalletLogPrintf("setKeyPool.size() = %u\n",      walletInstance->GetKeyPoolSize());
         walletInstance->WalletLogPrintf("mapWallet.size() = %u\n",       walletInstance->mapWallet.size());
-        walletInstance->WalletLogPrintf("mapAddressBook.size() = %u\n",  walletInstance->mapAddressBook.size());
+        walletInstance->WalletLogPrintf("m_address_book.size() = %u\n",  walletInstance->m_address_book.size());
     }
 
     return walletInstance;
 }
 
+const CAddressBookData* CWallet::FindAddressBookEntry(const CTxDestination& dest, bool allow_change) const
+{
+    const auto& address_book_it = m_address_book.find(dest);
+    if (address_book_it == m_address_book.end()) return nullptr;
+    if ((!allow_change) && address_book_it->second.IsChange()) {
+        return nullptr;
+    }
+    return &address_book_it->second;
+}
+
 void CWallet::postInitProcess()
 {
     auto locked_chain = chain().lock();

src/wallet/wallet.h

@@ -181,14 +181,23 @@ class ReserveDestination
 /** Address book data */
 class CAddressBookData
 {
+private:
+    bool m_change{true};
+    std::string m_label;
 public:
-    std::string name;
+    const std::string& name;
     std::string purpose;
 
-    CAddressBookData() : purpose("unknown") {}
+    CAddressBookData() : name(m_label), purpose("unknown") {}
 
     typedef std::map<std::string, std::string> StringMap;
     StringMap destdata;
+
+    bool IsChange() const { return m_change; }
+    void SetLabel(const std::string& label) {
+        m_change = false;
+        m_label = label;
+    }
 };
 
 struct CRecipient
@@ -775,7 +784,8 @@ class CWallet final : public WalletStorage, public interfaces::Chain::Notificati
     int64_t nOrderPosNext GUARDED_BY(cs_wallet) = 0;
     uint64_t nAccountingEntryNumber = 0;
 
-    std::map<CTxDestination, CAddressBookData> mapAddressBook GUARDED_BY(cs_wallet);
+    std::map<CTxDestination, CAddressBookData> m_address_book GUARDED_BY(cs_wallet);
+    const CAddressBookData* FindAddressBookEntry(const CTxDestination&, bool allow_change = false) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     std::set<COutPoint> setLockedCoins GUARDED_BY(cs_wallet);
 
@@ -842,7 +852,10 @@ class CWallet final : public WalletStorage, public interfaces::Chain::Notificati
 
     bool LoadMinVersion(int nVersion) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet) { AssertLockHeld(cs_wallet); nWalletVersion = nVersion; nWalletMaxVersion = std::max(nWalletMaxVersion, nVersion); return true; }
 
-    //! Adds a destination data tuple to the store, and saves it to disk
+    /**
+     * Adds a destination data tuple to the store, and saves it to disk
+     * When adding new fields, take care to consider how DelAddressBook should handle it!
+     */
     bool AddDestData(WalletBatch& batch, const CTxDestination& dest, const std::string& key, const std::string& value) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     //! Erases a destination data tuple in the store and on disk
     bool EraseDestData(WalletBatch& batch, const CTxDestination& dest, const std::string& key) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);

src/wallet/walletdb.cpp

@@ -206,11 +206,13 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
         if (strType == DBKeys::NAME) {
             std::string strAddress;
             ssKey >> strAddress;
-            ssValue >> pwallet->mapAddressBook[DecodeDestination(strAddress)].name;
+            std::string label;
+            ssValue >> label;
+            pwallet->m_address_book[DecodeDestination(strAddress)].SetLabel(label);
         } else if (strType == DBKeys::PURPOSE) {
             std::string strAddress;
             ssKey >> strAddress;
-            ssValue >> pwallet->mapAddressBook[DecodeDestination(strAddress)].purpose;
+            ssValue >> pwallet->m_address_book[DecodeDestination(strAddress)].purpose;
         } else if (strType == DBKeys::TX) {
             uint256 hash;
             ssKey >> hash;