[Wallet] Back port FindMySaplingNotes().

src/sapling/saplingscriptpubkeyman.cpp

@@ -4,6 +4,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include "sapling/saplingscriptpubkeyman.h"
+#include "sapling/note.hpp"
 #include "chain.h" // for CBlockIndex
 #include "validation.h" // for ReadBlockFromDisk()
 
@@ -212,6 +213,50 @@ void SaplingScriptPubKeyMan::DecrementNoteWitnesses(const CBlockIndex* pindex)
     // of the wallet.dat is maintained).
 }
 
+/**
+ * Finds all output notes in the given transaction that have been sent to
+ * SaplingPaymentAddresses in this wallet.
+ *
+ * It should never be necessary to call this method with a CWalletTx, because
+ * the result of FindMySaplingNotes (for the addresses available at the time) will
+ * already have been cached in CWalletTx.mapSaplingNoteData.
+ */
+std::pair<mapSaplingNoteData_t, SaplingIncomingViewingKeyMap> SaplingScriptPubKeyMan::FindMySaplingNotes(const CTransaction &tx) const
+{
+    LOCK(wallet->cs_KeyStore);
+    uint256 hash = tx.GetHash();
+
+    mapSaplingNoteData_t noteData;
+    SaplingIncomingViewingKeyMap viewingKeysToAdd;
+
+    // Protocol Spec: 4.19 Block Chain Scanning (Sapling)
+    for (uint32_t i = 0; i < tx.sapData->vShieldedOutput.size(); ++i) {
+        const OutputDescription output = tx.sapData->vShieldedOutput[i];
+        for (auto it = wallet->mapSaplingFullViewingKeys.begin(); it != wallet->mapSaplingFullViewingKeys.end(); ++it) {
+            libzcash::SaplingIncomingViewingKey ivk = it->first;
+            auto result = libzcash::SaplingNotePlaintext::decrypt(output.encCiphertext, ivk, output.ephemeralKey, output.cmu);
+            if (!result) {
+                continue;
+            }
+
+            // Check if we already have it.
+            auto address = ivk.address(result.get().d);
+            if (address && wallet->mapSaplingIncomingViewingKeys.count(address.get()) == 0) {
+                viewingKeysToAdd[address.get()] = ivk;
+            }
+            // We don't cache the nullifier here as computing it requires knowledge of the note position
+            // in the commitment tree, which can only be determined when the transaction has been mined.
+            SaplingOutPoint op {hash, i};
+            SaplingNoteData nd;
+            nd.ivk = ivk;
+            noteData.insert(std::make_pair(op, nd));
+            break;
+        }
+    }
+
+    return std::make_pair(noteData, viewingKeysToAdd);
+}
+
 bool SaplingScriptPubKeyMan::UpdatedNoteData(const CWalletTx& wtxIn, CWalletTx& wtx)
 {
     bool unchangedSaplingFlag = (wtxIn.mapSaplingNoteData.empty() || wtxIn.mapSaplingNoteData == wtx.mapSaplingNoteData);

src/sapling/saplingscriptpubkeyman.h

@@ -86,6 +86,8 @@ enum KeyAddResult {
     KeyNotAdded,
 };
 
+typedef std::map<SaplingOutPoint, SaplingNoteData> mapSaplingNoteData_t;
+
 /*
  * Sapling keys manager
  * todo: add real description..
@@ -176,6 +178,10 @@ class SaplingScriptPubKeyMan {
     //! Return the spending key for the payment address (nullopt if the wallet has no spending key for such address)
     Optional<libzcash::SaplingExtendedSpendingKey> GetSpendingKeyForPaymentAddress(const libzcash::SaplingPaymentAddress &addr) const;
 
+    //! Finds all output notes in the given tx that have been sent to a
+    //! SaplingPaymentAddress in this wallet
+    std::pair<mapSaplingNoteData_t, SaplingIncomingViewingKeyMap> FindMySaplingNotes(const CTransaction& tx) const;
+
     //! Update note data if is needed
     bool UpdatedNoteData(const CWalletTx& wtxIn, CWalletTx& wtx);
 

src/wallet/wallet.cpp

@@ -965,7 +965,22 @@ bool CWallet::AddToWalletIfInvolvingMe(const CTransaction& tx, const CBlockIndex
 
         bool fExisted = mapWallet.count(tx.GetHash()) != 0;
         if (fExisted && !fUpdate) return false;
-        if (fExisted || IsMine(tx) || IsFromMe(tx)) {
+
+        // Check tx for Sapling notes
+        mapSaplingNoteData_t saplingNoteData;
+        if (HasSaplingSPKM()) {
+            auto saplingNoteDataAndAddressesToAdd = m_sspk_man->FindMySaplingNotes(tx);
+            saplingNoteData = saplingNoteDataAndAddressesToAdd.first;
+            auto addressesToAdd = saplingNoteDataAndAddressesToAdd.second;
+            // Add my addresses addresses
+            for (const auto &addressToAdd : addressesToAdd) {
+                if (!m_sspk_man->AddSaplingIncomingViewingKey(addressToAdd.second, addressToAdd.first)) {
+                    return false;
+                }
+            }
+        }
+
+        if (fExisted || IsMine(tx) || IsFromMe(tx) || saplingNoteData.size() > 0) {
 
             /* Check if any keys in the wallet keypool that were supposed to be unused
              * have appeared in a new transaction. If so, remove those keys from the keypool.
@@ -979,6 +994,11 @@ bool CWallet::AddToWalletIfInvolvingMe(const CTransaction& tx, const CBlockIndex
             }
 
             CWalletTx wtx(this, tx);
+
+            if (saplingNoteData.size() > 0) {
+                wtx.SetSaplingNoteData(saplingNoteData);
+            }
+
             // Get merkle branch if transaction was found in a block
             if (posInBlock != -1)
                 wtx.SetMerkleBranch(pIndex, posInBlock);