333e1eaeea
- Bump copyright headers to 2015 - [devtools] Rewrite fix-copyright-headers.py - [devtools] Use git pretty-format for year parsing Github-Pull: #7205 Rebased-From: fa6ad855e9159b2247da4fa0054f32fa181499ab fa24439ff3d8ab5b9efaf66ef4dae6713b88cb35 fa71669452e57039e4270fd2b33a0e0e1635b813
114 lines
3.0 KiB
C++
114 lines
3.0 KiB
C++
// Copyright (c) 2009-2010 Satoshi Nakamoto
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// Copyright (c) 2009-2015 The Bitcoin Core developers
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// Distributed under the MIT software license, see the accompanying
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// file COPYING or http://www.opensource.org/licenses/mit-license.php.
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#include "sigcache.h"
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#include "memusage.h"
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#include "pubkey.h"
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#include "random.h"
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#include "uint256.h"
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#include "util.h"
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#include <boost/thread.hpp>
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#include <boost/unordered_set.hpp>
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namespace {
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/**
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* We're hashing a nonce into the entries themselves, so we don't need extra
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* blinding in the set hash computation.
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*/
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class CSignatureCacheHasher
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{
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public:
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size_t operator()(const uint256& key) const {
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return key.GetCheapHash();
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}
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};
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/**
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* Valid signature cache, to avoid doing expensive ECDSA signature checking
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* twice for every transaction (once when accepted into memory pool, and
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* again when accepted into the block chain)
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*/
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class CSignatureCache
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{
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private:
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//! Entries are SHA256(nonce || signature hash || public key || signature):
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uint256 nonce;
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typedef boost::unordered_set<uint256, CSignatureCacheHasher> map_type;
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map_type setValid;
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boost::shared_mutex cs_sigcache;
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public:
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CSignatureCache()
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{
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GetRandBytes(nonce.begin(), 32);
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}
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void
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ComputeEntry(uint256& entry, const uint256 &hash, const std::vector<unsigned char>& vchSig, const CPubKey& pubkey)
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{
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CSHA256().Write(nonce.begin(), 32).Write(hash.begin(), 32).Write(&pubkey[0], pubkey.size()).Write(&vchSig[0], vchSig.size()).Finalize(entry.begin());
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}
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bool
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Get(const uint256& entry)
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{
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boost::shared_lock<boost::shared_mutex> lock(cs_sigcache);
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return setValid.count(entry);
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}
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void Erase(const uint256& entry)
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{
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boost::unique_lock<boost::shared_mutex> lock(cs_sigcache);
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setValid.erase(entry);
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}
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void Set(const uint256& entry)
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{
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size_t nMaxCacheSize = GetArg("-maxsigcachesize", DEFAULT_MAX_SIG_CACHE_SIZE) * ((size_t) 1 << 20);
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if (nMaxCacheSize <= 0) return;
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boost::unique_lock<boost::shared_mutex> lock(cs_sigcache);
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while (memusage::DynamicUsage(setValid) > nMaxCacheSize)
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{
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map_type::size_type s = GetRand(setValid.bucket_count());
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map_type::local_iterator it = setValid.begin(s);
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if (it != setValid.end(s)) {
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setValid.erase(*it);
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}
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}
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setValid.insert(entry);
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}
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};
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}
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bool CachingTransactionSignatureChecker::VerifySignature(const std::vector<unsigned char>& vchSig, const CPubKey& pubkey, const uint256& sighash) const
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{
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static CSignatureCache signatureCache;
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uint256 entry;
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signatureCache.ComputeEntry(entry, sighash, vchSig, pubkey);
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if (signatureCache.Get(entry)) {
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if (!store) {
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signatureCache.Erase(entry);
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}
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return true;
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}
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if (!TransactionSignatureChecker::VerifySignature(vchSig, pubkey, sighash))
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return false;
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if (store) {
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signatureCache.Set(entry);
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}
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return true;
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}
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