Merge #9294: Use internal HD chain for change outputs (hd split)

4115af7 Fix rebase issue where pwalletMain was used instead of pwallet Ser./Deser. nInternalChainCounter as last element (Jonas Schnelli)
9382f04 Do not break backward compatibility during wallet encryption (Jonas Schnelli)
1df08d1 Add assertion for CanSupportFeature(FEATURE_HD_SPLIT) (Jonas Schnelli)
cd468d0 Define CWallet::DeriveNewChildKey() as private (Jonas Schnelli)
ed79e4f Optimize GetOldestKeyPoolTime(), return as soon as we have both oldest keys (Jonas Schnelli)
771a304 Make sure we set the wallets min version to FEATURE_HD_SPLIT at the very first point (Jonas Schnelli)
1b3b5c6 Slightly modify fundrawtransaction.py test (change getnewaddress() into getrawchangeaddress()) (Jonas Schnelli)
003e197 Remove FEATURE_HD_SPLIT bump TODO (Jonas Schnelli)
d9638e5 Overhaul the internal/external key derive switch (Jonas Schnelli)
1090502 Fix superfluous cast and code style nits in RPC wallet-hd.py test (Jonas Schnelli)
58e1483 CKeyPool avoid "catch (...)" in SerializationOp (Jonas Schnelli)
e138876 Only show keypoolsize_hd_internal if HD split is enabled (Jonas Schnelli)
add38d9 GetOldestKeyPoolTime: if HD & HD Chain Split is enabled, response max(oldest-internal-key, oldest-external-key) (Jonas Schnelli)
dd526c2 Don't switch to HD-chain-split during wallet encryption of non HD-chain-split wallets (Jonas Schnelli)
79df9df Switch to 100% for the HD internal keypool size (Jonas Schnelli)
bcafca1 Make sure we always generate one keypool key at minimum (Jonas Schnelli)
d0a627a Fix issue where CDataStream->nVersion was taken a CKeyPool record version (Jonas Schnelli)
9af8f00 Make sure we hand out keypool keys if HD_SPLIT is not enabled (Jonas Schnelli)
469a47b Make sure ReserveKeyFromKeyPool only hands out internal keys if HD_SPLIT is supported (Jonas Schnelli)
05a9b49 Fix wrong keypool internal size in RPC getwalletinfo help (Jonas Schnelli)
01de822 Removed redundant IsLocked() check in NewKeyPool() (Jonas Schnelli)
d59531d Immediately return setKeyPool's size if HD or HD_SPLIT is disabled or not supported (Jonas Schnelli)
02592f4 [Wallet] split the keypool in an internal and external part (Jonas Schnelli)

Tree-SHA512: 80d355d5e844b48c3163b56c788ab8b5b5285db0ceeb19858a3ef517d5a702afeca21dbae526d7b8fb4101c2a745af1d92bf557c40cf516780f17992bf678c1a

1 files changed, 30 insertions, 8 deletions

diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index ae4321eef8..ccede60097 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -86,6 +86,9 @@ enum WalletFeature
     FEATURE_COMPRPUBKEY = 60000, // compressed public keys
 
     FEATURE_HD = 130000, // Hierarchical key derivation after BIP32 (HD Wallet)
+
+    FEATURE_HD_SPLIT = 139900, // Wallet with HD chain split (change outputs will use m/0'/1'/k)
+
     FEATURE_LATEST = FEATURE_COMPRPUBKEY // HD is optional, use FEATURE_COMPRPUBKEY as latest version
 };
 
@@ -96,9 +99,10 @@ class CKeyPool
 public:
     int64_t nTime;
     CPubKey vchPubKey;
+    bool fInternal; // for change outputs
 
     CKeyPool();
-    CKeyPool(const CPubKey& vchPubKeyIn);
+    CKeyPool(const CPubKey& vchPubKeyIn, bool internalIn);
 
     ADD_SERIALIZE_METHODS;
 
@@ -109,6 +113,19 @@ public:
             READWRITE(nVersion);
         READWRITE(nTime);
         READWRITE(vchPubKey);
+        if (ser_action.ForRead()) {
+            try {
+                READWRITE(fInternal);
+            }
+            catch (std::ios_base::failure&) {
+                /* flag as external address if we can't read the internal boolean
+                   (this will be the case for any wallet before the HD chain split version) */
+                fInternal = false;
+            }
+        }
+        else {
+            READWRITE(fInternal);
+        }
     }
 };
 
@@ -647,6 +664,9 @@ private:
     /* the HD chain data model (external chain counters) */
     CHDChain hdChain;
 
+    /* HD derive new child key (on internal or external chain) */
+    void DeriveNewChildKey(CKeyMetadata& metadata, CKey& secret, bool internal = false);
+
     bool fFileBacked;
 
     std::set<int64_t> setKeyPool;
@@ -774,8 +794,7 @@ public:
      * keystore implementation
      * Generate a new key
      */
-    CPubKey GenerateNewKey();
-    void DeriveNewChildKey(CKeyMetadata& metadata, CKey& secret);
+    CPubKey GenerateNewKey(bool internal = false);
     //! Adds a key to the store, and saves it to disk.
     bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey) override;
     //! Adds a key to the store, without saving it to disk (used by LoadWallet)
@@ -883,11 +902,12 @@ public:
     static CAmount GetRequiredFee(unsigned int nTxBytes);
 
     bool NewKeyPool();
+    size_t KeypoolCountExternalKeys();
     bool TopUpKeyPool(unsigned int kpSize = 0);
-    void ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool);
+    void ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool internal);
     void KeepKey(int64_t nIndex);
     void ReturnKey(int64_t nIndex);
-    bool GetKeyFromPool(CPubKey &key);
+    bool GetKeyFromPool(CPubKey &key, bool internal = false);
     int64_t GetOldestKeyPoolTime();
     void GetAllReserveKeys(std::set<CKeyID>& setAddress) const;
 
@@ -1035,8 +1055,10 @@ public:
     /* 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 CPubKey& key);
+    /* Set the current HD master key (will reset the chain child index counters)
+       If possibleOldChain is provided, the parameters from the old chain (version)
+       will be preserved. */
+    bool SetHDMasterKey(const CPubKey& key, CHDChain *possibleOldChain = nullptr);
 };
 
 /** A key allocated from the key pool. */
@@ -1063,7 +1085,7 @@ public:
     }
 
     void ReturnKey();
-    bool GetReservedKey(CPubKey &pubkey);
+    bool GetReservedKey(CPubKey &pubkey, bool internal = false);
     void KeepKey();
     void KeepScript() { KeepKey(); }
 };