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339 lines
11 KiB
339 lines
11 KiB
// Copyright (c) 2009-2010 Satoshi Nakamoto |
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// Copyright (c) 2009-2014 The Bitcoin developers |
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// Distributed under the MIT/X11 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 "core.h" |
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#include "hash.h" |
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#include "tinyformat.h" |
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#include "utilstrencodings.h" |
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std::string COutPoint::ToString() const |
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{ |
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return strprintf("COutPoint(%s, %u)", hash.ToString().substr(0,10), n); |
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} |
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CTxIn::CTxIn(COutPoint prevoutIn, CScript scriptSigIn, uint32_t nSequenceIn) |
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{ |
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prevout = prevoutIn; |
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scriptSig = scriptSigIn; |
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nSequence = nSequenceIn; |
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} |
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CTxIn::CTxIn(uint256 hashPrevTx, uint32_t nOut, CScript scriptSigIn, uint32_t nSequenceIn) |
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{ |
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prevout = COutPoint(hashPrevTx, nOut); |
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scriptSig = scriptSigIn; |
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nSequence = nSequenceIn; |
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} |
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std::string CTxIn::ToString() const |
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{ |
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std::string str; |
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str += "CTxIn("; |
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str += prevout.ToString(); |
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if (prevout.IsNull()) |
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str += strprintf(", coinbase %s", HexStr(scriptSig)); |
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else |
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str += strprintf(", scriptSig=%s", scriptSig.ToString().substr(0,24)); |
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if (nSequence != std::numeric_limits<unsigned int>::max()) |
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str += strprintf(", nSequence=%u", nSequence); |
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str += ")"; |
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return str; |
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} |
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CTxOut::CTxOut(const CAmount& nValueIn, CScript scriptPubKeyIn) |
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{ |
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nValue = nValueIn; |
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scriptPubKey = scriptPubKeyIn; |
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} |
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uint256 CTxOut::GetHash() const |
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{ |
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return SerializeHash(*this); |
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} |
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std::string CTxOut::ToString() const |
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{ |
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return strprintf("CTxOut(nValue=%d.%08d, scriptPubKey=%s)", nValue / COIN, nValue % COIN, scriptPubKey.ToString().substr(0,30)); |
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} |
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CFeeRate::CFeeRate(const CAmount& nFeePaid, size_t nSize) |
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{ |
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if (nSize > 0) |
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nSatoshisPerK = nFeePaid*1000/nSize; |
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else |
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nSatoshisPerK = 0; |
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} |
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CAmount CFeeRate::GetFee(size_t nSize) const |
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{ |
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CAmount nFee = nSatoshisPerK*nSize / 1000; |
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if (nFee == 0 && nSatoshisPerK > 0) |
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nFee = nSatoshisPerK; |
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return nFee; |
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} |
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std::string CFeeRate::ToString() const |
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{ |
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return strprintf("%d.%08d BTC/kB", nSatoshisPerK / COIN, nSatoshisPerK % COIN); |
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} |
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CMutableTransaction::CMutableTransaction() : nVersion(CTransaction::CURRENT_VERSION), nLockTime(0) {} |
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CMutableTransaction::CMutableTransaction(const CTransaction& tx) : nVersion(tx.nVersion), vin(tx.vin), vout(tx.vout), nLockTime(tx.nLockTime) {} |
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uint256 CMutableTransaction::GetHash() const |
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{ |
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return SerializeHash(*this); |
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} |
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void CTransaction::UpdateHash() const |
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{ |
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*const_cast<uint256*>(&hash) = SerializeHash(*this); |
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} |
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CTransaction::CTransaction() : hash(0), nVersion(CTransaction::CURRENT_VERSION), vin(), vout(), nLockTime(0) { } |
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CTransaction::CTransaction(const CMutableTransaction &tx) : nVersion(tx.nVersion), vin(tx.vin), vout(tx.vout), nLockTime(tx.nLockTime) { |
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UpdateHash(); |
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} |
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CTransaction& CTransaction::operator=(const CTransaction &tx) { |
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*const_cast<int*>(&nVersion) = tx.nVersion; |
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*const_cast<std::vector<CTxIn>*>(&vin) = tx.vin; |
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*const_cast<std::vector<CTxOut>*>(&vout) = tx.vout; |
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*const_cast<unsigned int*>(&nLockTime) = tx.nLockTime; |
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*const_cast<uint256*>(&hash) = tx.hash; |
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return *this; |
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} |
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CAmount CTransaction::GetValueOut() const |
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{ |
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CAmount nValueOut = 0; |
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for (std::vector<CTxOut>::const_iterator it(vout.begin()); it != vout.end(); ++it) |
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{ |
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nValueOut += it->nValue; |
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if (!MoneyRange(it->nValue) || !MoneyRange(nValueOut)) |
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throw std::runtime_error("CTransaction::GetValueOut() : value out of range"); |
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} |
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return nValueOut; |
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} |
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double CTransaction::ComputePriority(double dPriorityInputs, unsigned int nTxSize) const |
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{ |
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nTxSize = CalculateModifiedSize(nTxSize); |
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if (nTxSize == 0) return 0.0; |
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return dPriorityInputs / nTxSize; |
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} |
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unsigned int CTransaction::CalculateModifiedSize(unsigned int nTxSize) const |
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{ |
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// In order to avoid disincentivizing cleaning up the UTXO set we don't count |
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// the constant overhead for each txin and up to 110 bytes of scriptSig (which |
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// is enough to cover a compressed pubkey p2sh redemption) for priority. |
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// Providing any more cleanup incentive than making additional inputs free would |
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// risk encouraging people to create junk outputs to redeem later. |
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if (nTxSize == 0) |
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nTxSize = ::GetSerializeSize(*this, SER_NETWORK, PROTOCOL_VERSION); |
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for (std::vector<CTxIn>::const_iterator it(vin.begin()); it != vin.end(); ++it) |
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{ |
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unsigned int offset = 41U + std::min(110U, (unsigned int)it->scriptSig.size()); |
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if (nTxSize > offset) |
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nTxSize -= offset; |
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} |
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return nTxSize; |
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} |
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std::string CTransaction::ToString() const |
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{ |
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std::string str; |
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str += strprintf("CTransaction(hash=%s, ver=%d, vin.size=%u, vout.size=%u, nLockTime=%u)\n", |
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GetHash().ToString().substr(0,10), |
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nVersion, |
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vin.size(), |
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vout.size(), |
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nLockTime); |
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for (unsigned int i = 0; i < vin.size(); i++) |
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str += " " + vin[i].ToString() + "\n"; |
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for (unsigned int i = 0; i < vout.size(); i++) |
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str += " " + vout[i].ToString() + "\n"; |
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return str; |
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} |
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// Amount compression: |
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// * If the amount is 0, output 0 |
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// * first, divide the amount (in base units) by the largest power of 10 possible; call the exponent e (e is max 9) |
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// * if e<9, the last digit of the resulting number cannot be 0; store it as d, and drop it (divide by 10) |
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// * call the result n |
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// * output 1 + 10*(9*n + d - 1) + e |
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// * if e==9, we only know the resulting number is not zero, so output 1 + 10*(n - 1) + 9 |
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// (this is decodable, as d is in [1-9] and e is in [0-9]) |
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uint64_t CTxOutCompressor::CompressAmount(uint64_t n) |
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{ |
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if (n == 0) |
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return 0; |
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int e = 0; |
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while (((n % 10) == 0) && e < 9) { |
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n /= 10; |
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e++; |
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} |
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if (e < 9) { |
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int d = (n % 10); |
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assert(d >= 1 && d <= 9); |
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n /= 10; |
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return 1 + (n*9 + d - 1)*10 + e; |
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} else { |
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return 1 + (n - 1)*10 + 9; |
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} |
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} |
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uint64_t CTxOutCompressor::DecompressAmount(uint64_t x) |
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{ |
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// x = 0 OR x = 1+10*(9*n + d - 1) + e OR x = 1+10*(n - 1) + 9 |
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if (x == 0) |
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return 0; |
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x--; |
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// x = 10*(9*n + d - 1) + e |
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int e = x % 10; |
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x /= 10; |
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uint64_t n = 0; |
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if (e < 9) { |
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// x = 9*n + d - 1 |
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int d = (x % 9) + 1; |
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x /= 9; |
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// x = n |
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n = x*10 + d; |
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} else { |
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n = x+1; |
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} |
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while (e) { |
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n *= 10; |
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e--; |
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} |
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return n; |
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} |
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uint256 CBlockHeader::GetHash() const |
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{ |
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return Hash(BEGIN(nVersion), END(nNonce)); |
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} |
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uint256 CBlock::BuildMerkleTree(bool* fMutated) const |
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{ |
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/* WARNING! If you're reading this because you're learning about crypto |
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and/or designing a new system that will use merkle trees, keep in mind |
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that the following merkle tree algorithm has a serious flaw related to |
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duplicate txids, resulting in a vulnerability (CVE-2012-2459). |
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The reason is that if the number of hashes in the list at a given time |
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is odd, the last one is duplicated before computing the next level (which |
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is unusual in Merkle trees). This results in certain sequences of |
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transactions leading to the same merkle root. For example, these two |
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trees: |
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A A |
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/ \ / \ |
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B C B C |
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/ \ | / \ / \ |
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D E F D E F F |
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/ \ / \ / \ / \ / \ / \ / \ |
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1 2 3 4 5 6 1 2 3 4 5 6 5 6 |
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for transaction lists [1,2,3,4,5,6] and [1,2,3,4,5,6,5,6] (where 5 and |
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6 are repeated) result in the same root hash A (because the hash of both |
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of (F) and (F,F) is C). |
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The vulnerability results from being able to send a block with such a |
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transaction list, with the same merkle root, and the same block hash as |
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the original without duplication, resulting in failed validation. If the |
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receiving node proceeds to mark that block as permanently invalid |
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however, it will fail to accept further unmodified (and thus potentially |
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valid) versions of the same block. We defend against this by detecting |
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the case where we would hash two identical hashes at the end of the list |
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together, and treating that identically to the block having an invalid |
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merkle root. Assuming no double-SHA256 collisions, this will detect all |
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known ways of changing the transactions without affecting the merkle |
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root. |
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*/ |
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vMerkleTree.clear(); |
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vMerkleTree.reserve(vtx.size() * 2 + 16); // Safe upper bound for the number of total nodes. |
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for (std::vector<CTransaction>::const_iterator it(vtx.begin()); it != vtx.end(); ++it) |
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vMerkleTree.push_back(it->GetHash()); |
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int j = 0; |
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bool mutated = false; |
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for (int nSize = vtx.size(); nSize > 1; nSize = (nSize + 1) / 2) |
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{ |
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for (int i = 0; i < nSize; i += 2) |
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{ |
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int i2 = std::min(i+1, nSize-1); |
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if (i2 == i + 1 && i2 + 1 == nSize && vMerkleTree[j+i] == vMerkleTree[j+i2]) { |
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// Two identical hashes at the end of the list at a particular level. |
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mutated = true; |
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} |
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vMerkleTree.push_back(Hash(BEGIN(vMerkleTree[j+i]), END(vMerkleTree[j+i]), |
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BEGIN(vMerkleTree[j+i2]), END(vMerkleTree[j+i2]))); |
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} |
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j += nSize; |
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} |
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if (fMutated) { |
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*fMutated = mutated; |
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} |
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return (vMerkleTree.empty() ? 0 : vMerkleTree.back()); |
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} |
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std::vector<uint256> CBlock::GetMerkleBranch(int nIndex) const |
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{ |
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if (vMerkleTree.empty()) |
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BuildMerkleTree(); |
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std::vector<uint256> vMerkleBranch; |
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int j = 0; |
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for (int nSize = vtx.size(); nSize > 1; nSize = (nSize + 1) / 2) |
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{ |
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int i = std::min(nIndex^1, nSize-1); |
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vMerkleBranch.push_back(vMerkleTree[j+i]); |
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nIndex >>= 1; |
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j += nSize; |
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} |
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return vMerkleBranch; |
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} |
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uint256 CBlock::CheckMerkleBranch(uint256 hash, const std::vector<uint256>& vMerkleBranch, int nIndex) |
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{ |
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if (nIndex == -1) |
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return 0; |
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for (std::vector<uint256>::const_iterator it(vMerkleBranch.begin()); it != vMerkleBranch.end(); ++it) |
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{ |
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if (nIndex & 1) |
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hash = Hash(BEGIN(*it), END(*it), BEGIN(hash), END(hash)); |
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else |
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hash = Hash(BEGIN(hash), END(hash), BEGIN(*it), END(*it)); |
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nIndex >>= 1; |
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} |
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return hash; |
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} |
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std::string CBlock::ToString() const |
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{ |
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std::stringstream s; |
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s << strprintf("CBlock(hash=%s, ver=%d, hashPrevBlock=%s, hashMerkleRoot=%s, nTime=%u, nBits=%08x, nNonce=%u, vtx=%u)\n", |
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GetHash().ToString(), |
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nVersion, |
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hashPrevBlock.ToString(), |
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hashMerkleRoot.ToString(), |
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nTime, nBits, nNonce, |
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vtx.size()); |
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for (unsigned int i = 0; i < vtx.size(); i++) |
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{ |
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s << " " << vtx[i].ToString() << "\n"; |
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} |
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s << " vMerkleTree: "; |
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for (unsigned int i = 0; i < vMerkleTree.size(); i++) |
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s << " " << vMerkleTree[i].ToString(); |
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s << "\n"; |
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return s.str(); |
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}
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