[0.13] Create a new HD seed after encrypting the wallet

https://github.com/bitcoin/bitcoin/pull/8389/commits

src/wallet/rpcwallet.cpp

@@ -2127,7 +2127,7 @@ UniValue encryptwallet(const UniValue& params, bool fHelp)
     // slack space in .dat files; that is bad if the old data is
     // unencrypted private keys. So:
     StartShutdown();
-    return "wallet encrypted; Bitcoin server stopping, restart to run with encrypted wallet. The keypool has been flushed, you need to make a new backup.";
+    return "wallet encrypted; Bitcoin server stopping, restart to run with encrypted wallet. The keypool has been flushed and a new HD seed was generated (if you are using HD). You need to make a new backup.";
 }
 
 UniValue lockunspent(const UniValue& params, bool fHelp)

src/wallet/wallet.cpp

@@ -946,6 +946,15 @@ bool CWallet::EncryptWallet(const SecureString& strWalletPassphrase)
 
         Lock();
         Unlock(strWalletPassphrase);
+
+        // if we are using HD, replace the HD master key with a new one
+        if (!hdChain.masterKeyID.IsNull()) {
+            CKey key;
+            key.MakeNewKey(true);
+            if (!SetHDMasterKey(key))
+                return false;
+        }
+
         NewKeyPool();
         Lock();
 
@@ -1378,19 +1387,42 @@ CAmount CWallet::GetChange(const CTxOut& txout) const
     return (IsChange(txout) ? txout.nValue : 0);
 }
 
+CPubKey CWallet::GenerateNewHDMasterKey()
+{
+    CKey key;
+    key.MakeNewKey(true);
+
+    int64_t nCreationTime = GetTime();
+    CKeyMetadata metadata(nCreationTime);
+
+    // 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 CKey& key)
 {
     LOCK(cs_wallet);
 
     // ensure this wallet.dat can only be opened by clients supporting HD
     SetMinVersion(FEATURE_HD);
-    
-    // store the key as normal "key"/"ckey" object
-    // in the database
-    // key metadata is not required
-    CPubKey pubkey = key.GetPubKey();
-    if (!AddKeyPubKey(key, pubkey))
-        throw std::runtime_error("CWallet::GenerateNewKey(): AddKey failed");
 
     // store the keyid (hash160) together with
     // the child index counter in the database

src/wallet/wallet.h

@@ -819,10 +819,13 @@ public:
     uint64_t GetStakeWeight() const;
     /* Set the hd chain model (chain child index counters) */
     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);
-    const CHDChain& GetHDChain() { return hdChain; }
+    bool SetHDMasterKey(const CPubKey& key);
 };
 
 /** A key allocated from the key pool. */