Merge #8851: [wallet] Move key derivation logic from GenerateNewKey to DeriveNewChildKey (pstratem)

e198c52 Move key derivation logic from GenerateNewKey to DeriveNewChildKey (Patrick Strateman)

src/wallet/wallet.cpp

@@ -100,6 +100,29 @@ CPubKey CWallet::GenerateNewKey()
 
     // use HD key derivation if HD was enabled during wallet creation
     if (IsHDEnabled()) {
+        DeriveNewChildKey(metadata, secret);
+    } else {
+        secret.MakeNewKey(fCompressed);
+    }
+
+    // Compressed public keys were introduced in version 0.6.0
+    if (fCompressed)
+        SetMinVersion(FEATURE_COMPRPUBKEY);
+
+    CPubKey pubkey = secret.GetPubKey();
+    assert(secret.VerifyPubKey(pubkey));
+
+    mapKeyMetadata[pubkey.GetID()] = metadata;
+    if (!nTimeFirstKey || nCreationTime < nTimeFirstKey)
+        nTimeFirstKey = nCreationTime;
+
+    if (!AddKeyPubKey(secret, pubkey))
+        throw std::runtime_error(std::string(__func__) + ": AddKey failed");
+    return pubkey;
+}
+
+void CWallet::DeriveNewChildKey(CKeyMetadata& metadata, CKey& secret)
+{
     // for now we use a fixed keypath scheme of m/0'/0'/k
     CKey key;                      //master key seed (256bit)
     CExtKey masterKey;             //hd master key
@@ -121,40 +144,21 @@ CPubKey CWallet::GenerateNewKey()
     accountKey.Derive(externalChainChildKey, BIP32_HARDENED_KEY_LIMIT);
 
     // derive child key at next index, skip keys already known to the wallet
-        do
+    do {
-        {
         // always derive hardened keys
         // childIndex | BIP32_HARDENED_KEY_LIMIT = derive childIndex in hardened child-index-range
         // example: 1 | BIP32_HARDENED_KEY_LIMIT == 0x80000001 == 2147483649
         externalChainChildKey.Derive(childKey, hdChain.nExternalChainCounter | BIP32_HARDENED_KEY_LIMIT);
-            metadata.hdKeypath     = "m/0'/0'/"+std::to_string(hdChain.nExternalChainCounter)+"'";
+        metadata.hdKeypath = "m/0'/0'/" + std::to_string(hdChain.nExternalChainCounter) + "'";
         metadata.hdMasterKeyID = hdChain.masterKeyID;
         // increment childkey index
         hdChain.nExternalChainCounter++;
-        } while(HaveKey(childKey.key.GetPubKey().GetID()));
+    } while (HaveKey(childKey.key.GetPubKey().GetID()));
     secret = childKey.key;
 
     // update the chain model in the database
     if (!CWalletDB(strWalletFile).WriteHDChain(hdChain))
         throw std::runtime_error(std::string(__func__) + ": Writing HD chain model failed");
-    } else {
-        secret.MakeNewKey(fCompressed);
-    }
-
-    // Compressed public keys were introduced in version 0.6.0
-    if (fCompressed)
-        SetMinVersion(FEATURE_COMPRPUBKEY);
-
-    CPubKey pubkey = secret.GetPubKey();
-    assert(secret.VerifyPubKey(pubkey));
-
-    mapKeyMetadata[pubkey.GetID()] = metadata;
-    if (!nTimeFirstKey || nCreationTime < nTimeFirstKey)
-        nTimeFirstKey = nCreationTime;
-
-    if (!AddKeyPubKey(secret, pubkey))
-        throw std::runtime_error(std::string(__func__) + ": AddKey failed");
-    return pubkey;
 }
 
 bool CWallet::AddKeyPubKey(const CKey& secret, const CPubKey &pubkey)

src/wallet/wallet.h

@@ -698,6 +698,7 @@ public:
      * Generate a new key
      */
     CPubKey GenerateNewKey();
+    void DeriveNewChildKey(CKeyMetadata& metadata, CKey& secret);
     //! Adds a key to the store, and saves it to disk.
     bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey);
     //! Adds a key to the store, without saving it to disk (used by LoadWallet)