sigcache.h

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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2016 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_SCRIPT_SIGCACHE_H
#define BITCOIN_SCRIPT_SIGCACHE_H
 
#include <script/interpreter.h>
#include <util/hasher.h>
 
#include <vector>
 
// DoS prevention: limit cache size to 32MB (over 1000000 entries on 64-bit
// systems). Due to how we count cache size, actual memory usage is slightly
// more (~32.25 MB)
static const unsigned int DEFAULT_MAX_SIG_CACHE_SIZE = 32;
// Maximum sig cache size allowed
static const int64_t MAX_MAX_SIG_CACHE_SIZE = 16384;
 
class CPubKey;
 
class CachingTransactionSignatureChecker : public TransactionSignatureChecker {
private:
    bool store;
 
    bool IsCached(const std::vector<uint8_t> &vchSig, const CPubKey &vchPubKey,
                  const uint256 &sighash) const;
 
public:
    CachingTransactionSignatureChecker(const CTransaction *txToIn,
                                       unsigned int nInIn,
                                       const Amount amountIn, bool storeIn,
                                       PrecomputedTransactionData &txdataIn)
        : TransactionSignatureChecker(txToIn, nInIn, amountIn, txdataIn),
          store(storeIn) {}
 
    bool VerifySignature(const std::vector<uint8_t> &vchSig,
                         const CPubKey &vchPubKey,
                         const uint256 &sighash) const override;
 
    friend class TestCachingTransactionSignatureChecker;
};
 
void InitSignatureCache();
 
#endif // BITCOIN_SCRIPT_SIGCACHE_H