[Wallet] Add CKeyMetadata record for HDMasterKey(s), factor out HD key generation

qa/rpc-tests/keypool.py

@@ -15,7 +15,7 @@ class KeyPoolTest(BitcoinTestFramework):
         addr_before_encrypting = nodes[0].getnewaddress()
         addr_before_encrypting_data = nodes[0].validateaddress(addr_before_encrypting)
         wallet_info_old = nodes[0].getwalletinfo()
-        assert(addr_before_encrypting_data['hdmasterkeyid'] == wallet_info_old['masterkeyid'])
+        assert(addr_before_encrypting_data['hdmasterkeyid'] == wallet_info_old['hdmasterkeyid'])
         
         # Encrypt wallet and wait to terminate
         nodes[0].encryptwallet('test')
@@ -26,8 +26,8 @@ class KeyPoolTest(BitcoinTestFramework):
         addr = nodes[0].getnewaddress()
         addr_data = nodes[0].validateaddress(addr)
         wallet_info = nodes[0].getwalletinfo()
-        assert(addr_before_encrypting_data['hdmasterkeyid'] != wallet_info['masterkeyid'])
-        assert(addr_data['hdmasterkeyid'] == wallet_info['masterkeyid'])
+        assert(addr_before_encrypting_data['hdmasterkeyid'] != wallet_info['hdmasterkeyid'])
+        assert(addr_data['hdmasterkeyid'] == wallet_info['hdmasterkeyid'])
         
         try:
             addr = nodes[0].getnewaddress()

src/wallet/wallet.cpp

@@ -627,11 +627,11 @@ bool CWallet::EncryptWallet(const SecureString& strWalletPassphrase)
         Lock();
         Unlock(strWalletPassphrase);
 
-        // if we are using HD, replace the HD master key with a new one
+        // if we are using HD, replace the HD master key (seed) with a new one
         if (!hdChain.masterKeyID.IsNull()) {
             CKey key;
-            key.MakeNewKey(true);
-            if (!SetHDMasterKey(key))
+            CPubKey masterPubKey = GenerateNewHDMasterKey();
+            if (!SetHDMasterKey(masterPubKey))
                 return false;
         }
 
@@ -1175,19 +1175,42 @@ CAmount CWallet::GetChange(const CTransaction& tx) const
     return nChange;
 }
 
-bool CWallet::SetHDMasterKey(const CKey& key)
+CPubKey CWallet::GenerateNewHDMasterKey()
 {
-    LOCK(cs_wallet);
+    CKey key;
+    key.MakeNewKey(true);
 
-    // ensure this wallet.dat can only be opened by clients supporting HD
-    SetMinVersion(FEATURE_HD);
+    int64_t nCreationTime = GetTime();
+    CKeyMetadata metadata(nCreationTime);
 
-    // store the key as normal "key"/"ckey" object
-    // in the database
-    // key metadata is not required
+    // calculate the pubkey
     CPubKey pubkey = key.GetPubKey();
+    assert(key.VerifyPubKey(pubkey));
+
+    // set the hd keypath to "m" -> Master, refers the masterkeyid to itself
+    metadata.hdKeypath     = "m";
+    metadata.hdMasterKeyID = pubkey.GetID();
+
+    {
+        LOCK(cs_wallet);
+
+        // mem store the metadata
+        mapKeyMetadata[pubkey.GetID()] = metadata;
+
+        // write the key&metadata to the database
         if (!AddKeyPubKey(key, pubkey))
             throw std::runtime_error("CWallet::GenerateNewKey(): AddKey failed");
+    }
+
+    return pubkey;
+}
+
+bool CWallet::SetHDMasterKey(const CPubKey& pubkey)
+{
+    LOCK(cs_wallet);
+
+    // ensure this wallet.dat can only be opened by clients supporting HD
+    SetMinVersion(FEATURE_HD);
 
     // store the keyid (hash160) together with
     // the child index counter in the database
@@ -3308,8 +3331,8 @@ bool CWallet::InitLoadWallet()
         if (GetBoolArg("-usehd", DEFAULT_USE_HD_WALLET) && walletInstance->hdChain.masterKeyID.IsNull()) {
             // generate a new master key
             CKey key;
-            key.MakeNewKey(true);
-            if (!walletInstance->SetHDMasterKey(key))
+            CPubKey masterPubKey = walletInstance->GenerateNewHDMasterKey();
+            if (!walletInstance->SetHDMasterKey(masterPubKey))
                 throw std::runtime_error("CWallet::GenerateNewKey(): Storing master key failed");
         }
         CPubKey newDefaultKey;

src/wallet/wallet.h

@@ -901,8 +901,11 @@ public:
     bool SetHDChain(const CHDChain& chain, bool memonly);
     const CHDChain& GetHDChain() { return hdChain; }
 
+    /* Generates a new HD master key (will not be activated) */
+    CPubKey GenerateNewHDMasterKey();
+    
     /* Set the current HD master key (will reset the chain child index counters) */
-    bool SetHDMasterKey(const CKey& key);
+    bool SetHDMasterKey(const CPubKey& key);
 };
 
 /** A key allocated from the key pool. */