improve wallet load time by removing duplicated calls to EC_KEY_check_key and adding a hash for vchPubKey/vchPrivKey entries in wallet.dat

backwards compatible with previous wallet.dat format

src/key.cpp

@@ -166,9 +166,12 @@ public:
         assert(nSize == nSize2);
     }
 
-    bool SetPrivKey(const CPrivKey &privkey) {
+    bool SetPrivKey(const CPrivKey &privkey, bool fSkipCheck=false) {
         const unsigned char* pbegin = &privkey[0];
         if (d2i_ECPrivateKey(&pkey, &pbegin, privkey.size())) {
+            if(fSkipCheck)
+                return true;
+            
             // d2i_ECPrivateKey returns true if parsing succeeds.
             // This doesn't necessarily mean the key is valid.
             if (EC_KEY_check_key(pkey))
@@ -409,6 +412,18 @@ bool CKey::SignCompact(const uint256 &hash, std::vector<unsigned char>& vchSig)
     return true;
 }
 
+bool CKey::Load(CPrivKey &privkey, CPubKey &vchPubKey, bool fSkipCheck=false) {
+    CECKey key;
+    if (!key.SetPrivKey(privkey, fSkipCheck))
+        return false;
+    
+    key.GetSecretBytes(vch);
+    fCompressed = vchPubKey.IsCompressed();
+    fValid = true;
+    
+    return true;
+}
+
 bool CPubKey::Verify(const uint256 &hash, const std::vector<unsigned char>& vchSig) const {
     if (!IsValid())
         return false;

src/key.h

@@ -261,6 +261,9 @@ public:
 
     // Derive BIP32 child key.
     bool Derive(CKey& keyChild, unsigned char ccChild[32], unsigned int nChild, const unsigned char cc[32]) const;
+    
+    // Load private key and check that public key matches.
+    bool Load(CPrivKey &privkey, CPubKey &vchPubKey, bool fSkipCheck);  
 };
 
 struct CExtPubKey {

src/walletdb.cpp

@@ -306,6 +306,8 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
             }
             CKey key;
             CPrivKey pkey;
+            uint256 hash = 0;
+            
             if (strType == "key")
             {
                 wss.nKeys++;
@@ -315,14 +317,34 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
                 ssValue >> wkey;
                 pkey = wkey.vchPrivKey;
             }
-            if (!key.SetPrivKey(pkey, vchPubKey.IsCompressed()))
+            try
             {
-                strErr = "Error reading wallet database: CPrivKey corrupt";
-                return false;
+                ssValue >> hash;
+            }
+            catch(...){}
+            
+            bool fSkipCheck = false;
+            
+            if (hash != 0)
+            {
+                // hash pubkey/privkey to accelerate wallet load
+                std::vector<unsigned char> vchKey;
+                vchKey.reserve(vchPubKey.size() + pkey.size());
+                vchKey.insert(vchKey.end(), vchPubKey.begin(), vchPubKey.end());
+                vchKey.insert(vchKey.end(), pkey.begin(), pkey.end());
+                
+                if (Hash(vchKey.begin(), vchKey.end()) != hash)
+                {
+                    strErr = "Error reading wallet database: CPubKey/CPrivKey corrupt";
+                    return false;
+                }
+                
+                fSkipCheck = true;
             }
-            if (key.GetPubKey() != vchPubKey)
+            
+            if (!key.Load(pkey, vchPubKey, fSkipCheck))
             {
-                strErr = "Error reading wallet database: CPrivKey pubkey inconsistency";
+                strErr = "Error reading wallet database: CPrivKey corrupt";
                 return false;
             }
             if (!pwallet->LoadKey(key, vchPubKey))

src/walletdb.h

@@ -94,7 +94,13 @@ public:
                    keyMeta))
             return false;
         
-        return Write(std::make_pair(std::string("key"), vchPubKey), vchPrivKey, false);
+        // hash pubkey/privkey to accelerate wallet load
+        std::vector<unsigned char> vchKey;
+        vchKey.reserve(vchPubKey.size() + vchPrivKey.size());
+        vchKey.insert(vchKey.end(), vchPubKey.begin(), vchPubKey.end());
+        vchKey.insert(vchKey.end(), vchPrivKey.begin(), vchPrivKey.end());
+        
+        return Write(std::make_pair(std::string("key"), vchPubKey), std::make_pair(vchPrivKey, Hash(vchKey.begin(), vchKey.end())), false);
     }
 
     bool WriteCryptedKey(const CPubKey& vchPubKey,