Add chainstate obfuscation to avoid spurious antivirus detection

Adds an `obfuscate` parameter to `CLevelDBWrapper` and makes use of it
for all new chainstate stores built via `CCoinsViewDB`. Also adds an
`Xor` method to `CDataStream`.

Thanks to @sipa @laanwj @pstratem @dexX7 @KyrosKrane @gmaxwell.

1 files changed, 10 insertions, 17 deletions

diff --git a/src/txdb.cpp b/src/txdb.cpp
index 21ecd65238..9738dea03d 100644
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -29,18 +29,8 @@ static const char DB_REINDEX_FLAG = 'R';
 static const char DB_LAST_BLOCK = 'l';
 
 
-void static BatchWriteCoins(CLevelDBBatch &batch, const uint256 &hash, const CCoins &coins) {
-    if (coins.IsPruned())
-        batch.Erase(make_pair(DB_COINS, hash));
-    else
-        batch.Write(make_pair(DB_COINS, hash), coins);
-}
-
-void static BatchWriteHashBestChain(CLevelDBBatch &batch, const uint256 &hash) {
-    batch.Write(DB_BEST_BLOCK, hash);
-}
-
-CCoinsViewDB::CCoinsViewDB(size_t nCacheSize, bool fMemory, bool fWipe) : db(GetDataDir() / "chainstate", nCacheSize, fMemory, fWipe) {
+CCoinsViewDB::CCoinsViewDB(size_t nCacheSize, bool fMemory, bool fWipe) : db(GetDataDir() / "chainstate", nCacheSize, fMemory, fWipe, true) 
+{
 }
 
 bool CCoinsViewDB::GetCoins(const uint256 &txid, CCoins &coins) const {
@@ -59,12 +49,15 @@ uint256 CCoinsViewDB::GetBestBlock() const {
 }
 
 bool CCoinsViewDB::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) {
-    CLevelDBBatch batch;
+    CLevelDBBatch batch(db.GetObfuscateKey());
     size_t count = 0;
     size_t changed = 0;
     for (CCoinsMap::iterator it = mapCoins.begin(); it != mapCoins.end();) {
         if (it->second.flags & CCoinsCacheEntry::DIRTY) {
-            BatchWriteCoins(batch, it->first, it->second.coins);
+            if (it->second.coins.IsPruned())
+                batch.Erase(make_pair(DB_COINS, it->first));
+            else
+                batch.Write(make_pair(DB_COINS, it->first), it->second.coins);
             changed++;
         }
         count++;
@@ -72,7 +65,7 @@ bool CCoinsViewDB::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) {
         mapCoins.erase(itOld);
     }
     if (!hashBlock.IsNull())
-        BatchWriteHashBestChain(batch, hashBlock);
+        batch.Write(DB_BEST_BLOCK, hashBlock);
 
     LogPrint("coindb", "Committing %u changed transactions (out of %u) to coin database...\n", (unsigned int)changed, (unsigned int)count);
     return db.WriteBatch(batch);
@@ -158,7 +151,7 @@ bool CCoinsViewDB::GetStats(CCoinsStats &stats) const {
 }
 
 bool CBlockTreeDB::WriteBatchSync(const std::vector<std::pair<int, const CBlockFileInfo*> >& fileInfo, int nLastFile, const std::vector<const CBlockIndex*>& blockinfo) {
-    CLevelDBBatch batch;
+    CLevelDBBatch batch(GetObfuscateKey());
     for (std::vector<std::pair<int, const CBlockFileInfo*> >::const_iterator it=fileInfo.begin(); it != fileInfo.end(); it++) {
         batch.Write(make_pair(DB_BLOCK_FILES, it->first), *it->second);
     }
@@ -174,7 +167,7 @@ bool CBlockTreeDB::ReadTxIndex(const uint256 &txid, CDiskTxPos &pos) {
 }
 
 bool CBlockTreeDB::WriteTxIndex(const std::vector<std::pair<uint256, CDiskTxPos> >&vect) {
-    CLevelDBBatch batch;
+    CLevelDBBatch batch(GetObfuscateKey());
     for (std::vector<std::pair<uint256,CDiskTxPos> >::const_iterator it=vect.begin(); it!=vect.end(); it++)
         batch.Write(make_pair(DB_TXINDEX, it->first), it->second);
     return WriteBatch(batch);