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Diffstat (limited to 'src/wallet/scriptpubkeyman.h')
| -rw-r--r-- | src/wallet/scriptpubkeyman.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/src/wallet/scriptpubkeyman.h b/src/wallet/scriptpubkeyman.h new file mode 100644 index 0000000000..f151cec444 --- /dev/null +++ b/src/wallet/scriptpubkeyman.h @@ -0,0 +1,115 @@ +// Copyright (c) 2019 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#ifndef BITCOIN_WALLET_SCRIPTPUBKEYMAN_H +#define BITCOIN_WALLET_SCRIPTPUBKEYMAN_H + +#include <script/signingprovider.h> +#include <script/standard.h> +#include <wallet/crypter.h> +#include <wallet/ismine.h> +#include <wallet/walletdb.h> +#include <wallet/walletutil.h> + +#include <boost/signals2/signal.hpp> + +enum class OutputType; + +//! Default for -keypool +static const unsigned int DEFAULT_KEYPOOL_SIZE = 1000; + +/** A key from a CWallet's keypool + * + * The wallet holds one (for pre HD-split wallets) or several keypools. These + * are sets of keys that have not yet been used to provide addresses or receive + * change. + * + * The Bitcoin Core wallet was originally a collection of unrelated private + * keys with their associated addresses. If a non-HD wallet generated a + * key/address, gave that address out and then restored a backup from before + * that key's generation, then any funds sent to that address would be + * lost definitively. + * + * The keypool was implemented to avoid this scenario (commit: 10384941). The + * wallet would generate a set of keys (100 by default). When a new public key + * was required, either to give out as an address or to use in a change output, + * it would be drawn from the keypool. The keypool would then be topped up to + * maintain 100 keys. This ensured that as long as the wallet hadn't used more + * than 100 keys since the previous backup, all funds would be safe, since a + * restored wallet would be able to scan for all owned addresses. + * + * A keypool also allowed encrypted wallets to give out addresses without + * having to be decrypted to generate a new private key. + * + * With the introduction of HD wallets (commit: f1902510), the keypool + * essentially became an address look-ahead pool. Restoring old backups can no + * longer definitively lose funds as long as the addresses used were from the + * wallet's HD seed (since all private keys can be rederived from the seed). + * However, if many addresses were used since the backup, then the wallet may + * not know how far ahead in the HD chain to look for its addresses. The + * keypool is used to implement a 'gap limit'. The keypool maintains a set of + * keys (by default 1000) ahead of the last used key and scans for the + * addresses of those keys. This avoids the risk of not seeing transactions + * involving the wallet's addresses, or of re-using the same address. + * + * The HD-split wallet feature added a second keypool (commit: 02592f4c). There + * is an external keypool (for addresses to hand out) and an internal keypool + * (for change addresses). + * + * Keypool keys are stored in the wallet/keystore's keymap. The keypool data is + * stored as sets of indexes in the wallet (setInternalKeyPool, + * setExternalKeyPool and set_pre_split_keypool), and a map from the key to the + * index (m_pool_key_to_index). The CKeyPool object is used to + * serialize/deserialize the pool data to/from the database. + */ +class CKeyPool +{ +public: + //! The time at which the key was generated. Set in AddKeypoolPubKeyWithDB + int64_t nTime; + //! The public key + CPubKey vchPubKey; + //! Whether this keypool entry is in the internal keypool (for change outputs) + bool fInternal; + //! Whether this key was generated for a keypool before the wallet was upgraded to HD-split + bool m_pre_split; + + CKeyPool(); + CKeyPool(const CPubKey& vchPubKeyIn, bool internalIn); + + ADD_SERIALIZE_METHODS; + + template <typename Stream, typename Operation> + inline void SerializationOp(Stream& s, Operation ser_action) { + int nVersion = s.GetVersion(); + if (!(s.GetType() & SER_GETHASH)) + 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; + } + try { + READWRITE(m_pre_split); + } + catch (std::ios_base::failure&) { + /* flag as postsplit address if we can't read the m_pre_split boolean + (this will be the case for any wallet that upgrades to HD chain split)*/ + m_pre_split = false; + } + } + else { + READWRITE(fInternal); + READWRITE(m_pre_split); + } + } +}; + +#endif // BITCOIN_WALLET_SCRIPTPUBKEYMAN_H |