Duplicate serializations of consensus objects to use as Bitcoin serialization

src/Makefile.am

@@ -288,6 +288,8 @@ libbitcoin_wallet_a_SOURCES = \
   wallet/walletdb.cpp \
   wallet/walletutil.cpp \
   wallet/coinselection.cpp \
+  primitives/bitcoin/merkleblock.cpp \
+  primitives/bitcoin/block.cpp \
   $(BITCOIN_CORE_H)
 
 # crypto primitives library
@@ -352,6 +354,12 @@ libbitcoin_consensus_a_SOURCES = \
   primitives/block.h \
   primitives/transaction.cpp \
   primitives/transaction.h \
+  primitives/bitcoin/block.cpp \
+  primitives/bitcoin/block.h \
+  primitives/bitcoin/merkleblock.cpp \
+  primitives/bitcoin/merkleblock.h \
+  primitives/bitcoin/transaction.cpp \
+  primitives/bitcoin/transaction.h \
   pubkey.cpp \
   pubkey.h \
   script/bitcoinconsensus.cpp \

src/primitives/bitcoin/block.cpp

@@ -0,0 +1,38 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <primitives/bitcoin/block.h>
+
+#include <hash.h>
+#include <tinyformat.h>
+#include <utilstrencodings.h>
+#include <crypto/common.h>
+
+namespace Sidechain {
+namespace Bitcoin {
+
+uint256 CBlockHeader::GetHash() const
+{
+    return SerializeHash(*this);
+}
+
+std::string CBlock::ToString() const
+{
+    std::stringstream s;
+    s << strprintf("CBlock(hash=%s, ver=0x%08x, hashPrevBlock=%s, hashMerkleRoot=%s, nTime=%u, nBits=%08x, nNonce=%u, vtx=%u)\n",
+        GetHash().ToString(),
+        nVersion,
+        hashPrevBlock.ToString(),
+        hashMerkleRoot.ToString(),
+        nTime, nBits, nNonce,
+        vtx.size());
+    for (const auto& tx : vtx) {
+        s << "  " << tx->ToString() << "\n";
+    }
+    return s.str();
+}
+
+} // Bitcoin
+} // Sidechain

src/primitives/bitcoin/block.h

@@ -0,0 +1,161 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 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_PRIMITIVES_BITCOIN_BLOCK_H
+#define BITCOIN_PRIMITIVES_BITCOIN_BLOCK_H
+
+#include <primitives/bitcoin/transaction.h>
+#include <serialize.h>
+#include <uint256.h>
+
+namespace Sidechain {
+namespace Bitcoin {
+
+/** Nodes collect new transactions into a block, hash them into a hash tree,
+ * and scan through nonce values to make the block's hash satisfy proof-of-work
+ * requirements.  When they solve the proof-of-work, they broadcast the block
+ * to everyone and the block is added to the block chain.  The first transaction
+ * in the block is a special one that creates a new coin owned by the creator
+ * of the block.
+ */
+class CBlockHeader
+{
+public:
+    // header
+    int32_t nVersion;
+    uint256 hashPrevBlock;
+    uint256 hashMerkleRoot;
+    uint32_t nTime;
+    uint32_t nBits;
+    uint32_t nNonce;
+
+    CBlockHeader()
+    {
+        SetNull();
+    }
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(this->nVersion);
+        READWRITE(hashPrevBlock);
+        READWRITE(hashMerkleRoot);
+        READWRITE(nTime);
+        READWRITE(nBits);
+        READWRITE(nNonce);
+    }
+
+    void SetNull()
+    {
+        nVersion = 0;
+        hashPrevBlock.SetNull();
+        hashMerkleRoot.SetNull();
+        nTime = 0;
+        nBits = 0;
+        nNonce = 0;
+    }
+
+    bool IsNull() const
+    {
+        return (nBits == 0);
+    }
+
+    uint256 GetHash() const;
+
+    int64_t GetBlockTime() const
+    {
+        return (int64_t)nTime;
+    }
+};
+
+
+class CBlock : public CBlockHeader
+{
+public:
+    // network and disk
+    std::vector<CTransactionRef> vtx;
+
+    // memory only
+    mutable bool fChecked;
+
+    CBlock()
+    {
+        SetNull();
+    }
+
+    CBlock(const CBlockHeader &header)
+    {
+        SetNull();
+        *(static_cast<CBlockHeader*>(this)) = header;
+    }
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITEAS(CBlockHeader, *this);
+        READWRITE(vtx);
+    }
+
+    void SetNull()
+    {
+        CBlockHeader::SetNull();
+        vtx.clear();
+        fChecked = false;
+    }
+
+    CBlockHeader GetBlockHeader() const
+    {
+        CBlockHeader block;
+        block.nVersion       = nVersion;
+        block.hashPrevBlock  = hashPrevBlock;
+        block.hashMerkleRoot = hashMerkleRoot;
+        block.nTime          = nTime;
+        block.nBits          = nBits;
+        block.nNonce         = nNonce;
+        return block;
+    }
+
+    std::string ToString() const;
+};
+
+/** Describes a place in the block chain to another node such that if the
+ * other node doesn't have the same branch, it can find a recent common trunk.
+ * The further back it is, the further before the fork it may be.
+ */
+struct CBlockLocator
+{
+    std::vector<uint256> vHave;
+
+    CBlockLocator() {}
+
+    explicit CBlockLocator(const std::vector<uint256>& vHaveIn) : vHave(vHaveIn) {}
+
+    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(vHave);
+    }
+
+    void SetNull()
+    {
+        vHave.clear();
+    }
+
+    bool IsNull() const
+    {
+        return vHave.empty();
+    }
+};
+
+} // namespace Bitcoin
+} // namespace Sidechain
+
+#endif // BITCOIN_PRIMITIVES_BITCOIN_BLOCK_H

src/primitives/bitcoin/merkleblock.cpp

@@ -0,0 +1,168 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <primitives/bitcoin/merkleblock.h>
+
+#include <hash.h>
+#include <consensus/consensus.h>
+#include <utilstrencodings.h>
+
+namespace Sidechain {
+namespace Bitcoin {
+/*
+CMerkleBlock::CMerkleBlock(const CBlock& block, CBloomFilter* filter, const std::set<uint256>* txids)
+{
+    header = block.GetBlockHeader();
+
+    std::vector<bool> vMatch;
+    std::vector<uint256> vHashes;
+
+    vMatch.reserve(block.vtx.size());
+    vHashes.reserve(block.vtx.size());
+
+    for (unsigned int i = 0; i < block.vtx.size(); i++)
+    {
+        const uint256& hash = block.vtx[i]->GetHash();
+        if (txids && txids->count(hash)) {
+            vMatch.push_back(true);
+        } else if (filter && filter->IsRelevantAndUpdate(*block.vtx[i])) {
+            vMatch.push_back(true);
+            vMatchedTxn.emplace_back(i, hash);
+        } else {
+            vMatch.push_back(false);
+        }
+        vHashes.push_back(hash);
+    }
+
+    txn = CPartialMerkleTree(vHashes, vMatch);
+}
+*/
+uint256 CPartialMerkleTree::CalcHash(int height, unsigned int pos, const std::vector<uint256> &vTxid) {
+    //we can never have zero txs in a merkle block, we always need the coinbase tx
+    //if we do not have this assert, we can hit a memory access violation when indexing into vTxid
+    assert(vTxid.size() != 0);
+    if (height == 0) {
+        // hash at height 0 is the txids themself
+        return vTxid[pos];
+    } else {
+        // calculate left hash
+        uint256 left = CalcHash(height-1, pos*2, vTxid), right;
+        // calculate right hash if not beyond the end of the array - copy left hash otherwise
+        if (pos*2+1 < CalcTreeWidth(height-1))
+            right = CalcHash(height-1, pos*2+1, vTxid);
+        else
+            right = left;
+        // combine subhashes
+        return Hash(BEGIN(left), END(left), BEGIN(right), END(right));
+    }
+}
+
+void CPartialMerkleTree::TraverseAndBuild(int height, unsigned int pos, const std::vector<uint256> &vTxid, const std::vector<bool> &vMatch) {
+    // determine whether this node is the parent of at least one matched txid
+    bool fParentOfMatch = false;
+    for (unsigned int p = pos << height; p < (pos+1) << height && p < nTransactions; p++)
+        fParentOfMatch |= vMatch[p];
+    // store as flag bit
+    vBits.push_back(fParentOfMatch);
+    if (height==0 || !fParentOfMatch) {
+        // if at height 0, or nothing interesting below, store hash and stop
+        vHash.push_back(CalcHash(height, pos, vTxid));
+    } else {
+        // otherwise, don't store any hash, but descend into the subtrees
+        TraverseAndBuild(height-1, pos*2, vTxid, vMatch);
+        if (pos*2+1 < CalcTreeWidth(height-1))
+            TraverseAndBuild(height-1, pos*2+1, vTxid, vMatch);
+    }
+}
+
+uint256 CPartialMerkleTree::TraverseAndExtract(int height, unsigned int pos, unsigned int &nBitsUsed, unsigned int &nHashUsed, std::vector<uint256> &vMatch, std::vector<unsigned int> &vnIndex) {
+    if (nBitsUsed >= vBits.size()) {
+        // overflowed the bits array - failure
+        fBad = true;
+        return uint256();
+    }
+    bool fParentOfMatch = vBits[nBitsUsed++];
+    if (height==0 || !fParentOfMatch) {
+        // if at height 0, or nothing interesting below, use stored hash and do not descend
+        if (nHashUsed >= vHash.size()) {
+            // overflowed the hash array - failure
+            fBad = true;
+            return uint256();
+        }
+        const uint256 &hash = vHash[nHashUsed++];
+        if (height==0 && fParentOfMatch) { // in case of height 0, we have a matched txid
+            vMatch.push_back(hash);
+            vnIndex.push_back(pos);
+        }
+        return hash;
+    } else {
+        // otherwise, descend into the subtrees to extract matched txids and hashes
+        uint256 left = TraverseAndExtract(height-1, pos*2, nBitsUsed, nHashUsed, vMatch, vnIndex), right;
+        if (pos*2+1 < CalcTreeWidth(height-1)) {
+            right = TraverseAndExtract(height-1, pos*2+1, nBitsUsed, nHashUsed, vMatch, vnIndex);
+            if (right == left) {
+                // The left and right branches should never be identical, as the transaction
+                // hashes covered by them must each be unique.
+                fBad = true;
+            }
+        } else {
+            right = left;
+        }
+        // and combine them before returning
+        return Hash(BEGIN(left), END(left), BEGIN(right), END(right));
+    }
+}
+
+CPartialMerkleTree::CPartialMerkleTree(const std::vector<uint256> &vTxid, const std::vector<bool> &vMatch) : nTransactions(vTxid.size()), fBad(false) {
+    // reset state
+    vBits.clear();
+    vHash.clear();
+
+    // calculate height of tree
+    int nHeight = 0;
+    while (CalcTreeWidth(nHeight) > 1)
+        nHeight++;
+
+    // traverse the partial tree
+    TraverseAndBuild(nHeight, 0, vTxid, vMatch);
+}
+
+CPartialMerkleTree::CPartialMerkleTree() : nTransactions(0), fBad(true) {}
+
+uint256 CPartialMerkleTree::ExtractMatches(std::vector<uint256> &vMatch, std::vector<unsigned int> &vnIndex) {
+    vMatch.clear();
+    // An empty set will not work
+    if (nTransactions == 0)
+        return uint256();
+    // check for excessively high numbers of transactions
+    if (nTransactions > MAX_BLOCK_WEIGHT / MIN_TRANSACTION_WEIGHT)
+        return uint256();
+    // there can never be more hashes provided than one for every txid
+    if (vHash.size() > nTransactions)
+        return uint256();
+    // there must be at least one bit per node in the partial tree, and at least one node per hash
+    if (vBits.size() < vHash.size())
+        return uint256();
+    // calculate height of tree
+    int nHeight = 0;
+    while (CalcTreeWidth(nHeight) > 1)
+        nHeight++;
+    // traverse the partial tree
+    unsigned int nBitsUsed = 0, nHashUsed = 0;
+    uint256 hashMerkleRoot = TraverseAndExtract(nHeight, 0, nBitsUsed, nHashUsed, vMatch, vnIndex);
+    // verify that no problems occurred during the tree traversal
+    if (fBad)
+        return uint256();
+    // verify that all bits were consumed (except for the padding caused by serializing it as a byte sequence)
+    if ((nBitsUsed+7)/8 != (vBits.size()+7)/8)
+        return uint256();
+    // verify that all hashes were consumed
+    if (nHashUsed != vHash.size())
+        return uint256();
+    return hashMerkleRoot;
+}
+
+} // namespace Bitcoin
+} // namespace Sidechain

src/primitives/bitcoin/merkleblock.h

@@ -0,0 +1,179 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 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_PRIMITIVES_BITCOIN_MERKLEBLOCK_H
+#define BITCOIN_PRIMITIVES_BITCOIN_MERKLEBLOCK_H
+
+#include <serialize.h>
+#include <uint256.h>
+#include <primitives/bitcoin/block.h>
+#include <bloom.h>
+
+#include <vector>
+
+namespace Sidechain {
+namespace Bitcoin {
+
+/** Data structure that represents a partial merkle tree.
+ *
+ * It represents a subset of the txid's of a known block, in a way that
+ * allows recovery of the list of txid's and the merkle root, in an
+ * authenticated way.
+ *
+ * The encoding works as follows: we traverse the tree in depth-first order,
+ * storing a bit for each traversed node, signifying whether the node is the
+ * parent of at least one matched leaf txid (or a matched txid itself). In
+ * case we are at the leaf level, or this bit is 0, its merkle node hash is
+ * stored, and its children are not explored further. Otherwise, no hash is
+ * stored, but we recurse into both (or the only) child branch. During
+ * decoding, the same depth-first traversal is performed, consuming bits and
+ * hashes as they written during encoding.
+ *
+ * The serialization is fixed and provides a hard guarantee about the
+ * encoded size:
+ *
+ *   SIZE <= 10 + ceil(32.25*N)
+ *
+ * Where N represents the number of leaf nodes of the partial tree. N itself
+ * is bounded by:
+ *
+ *   N <= total_transactions
+ *   N <= 1 + matched_transactions*tree_height
+ *
+ * The serialization format:
+ *  - uint32     total_transactions (4 bytes)
+ *  - varint     number of hashes   (1-3 bytes)
+ *  - uint256[]  hashes in depth-first order (<= 32*N bytes)
+ *  - varint     number of bytes of flag bits (1-3 bytes)
+ *  - byte[]     flag bits, packed per 8 in a byte, least significant bit first (<= 2*N-1 bits)
+ * The size constraints follow from this.
+ */
+class CPartialMerkleTree
+{
+protected:
+    /** the total number of transactions in the block */
+    unsigned int nTransactions;
+
+    /** node-is-parent-of-matched-txid bits */
+    std::vector<bool> vBits;
+
+    /** txids and internal hashes */
+    std::vector<uint256> vHash;
+
+    /** flag set when encountering invalid data */
+    bool fBad;
+
+    /** helper function to efficiently calculate the number of nodes at given height in the merkle tree */
+    unsigned int CalcTreeWidth(int height) const {
+        return (nTransactions+(1 << height)-1) >> height;
+    }
+
+    /** calculate the hash of a node in the merkle tree (at leaf level: the txid's themselves) */
+    uint256 CalcHash(int height, unsigned int pos, const std::vector<uint256> &vTxid);
+
+    /** recursive function that traverses tree nodes, storing the data as bits and hashes */
+    void TraverseAndBuild(int height, unsigned int pos, const std::vector<uint256> &vTxid, const std::vector<bool> &vMatch);
+
+    /**
+     * recursive function that traverses tree nodes, consuming the bits and hashes produced by TraverseAndBuild.
+     * it returns the hash of the respective node and its respective index.
+     */
+    uint256 TraverseAndExtract(int height, unsigned int pos, unsigned int &nBitsUsed, unsigned int &nHashUsed, std::vector<uint256> &vMatch, std::vector<unsigned int> &vnIndex);
+
+public:
+
+    /** serialization implementation */
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(nTransactions);
+        READWRITE(vHash);
+        std::vector<unsigned char> vBytes;
+        if (ser_action.ForRead()) {
+            READWRITE(vBytes);
+            CPartialMerkleTree &us = *(const_cast<CPartialMerkleTree*>(this));
+            us.vBits.resize(vBytes.size() * 8);
+            for (unsigned int p = 0; p < us.vBits.size(); p++)
+                us.vBits[p] = (vBytes[p / 8] & (1 << (p % 8))) != 0;
+            us.fBad = false;
+        } else {
+            vBytes.resize((vBits.size()+7)/8);
+            for (unsigned int p = 0; p < vBits.size(); p++)
+                vBytes[p / 8] |= vBits[p] << (p % 8);
+            READWRITE(vBytes);
+        }
+    }
+
+    /** Construct a partial merkle tree from a list of transaction ids, and a mask that selects a subset of them */
+    CPartialMerkleTree(const std::vector<uint256> &vTxid, const std::vector<bool> &vMatch);
+
+    CPartialMerkleTree();
+
+    /**
+     * extract the matching txid's represented by this partial merkle tree
+     * and their respective indices within the partial tree.
+     * returns the merkle root, or 0 in case of failure
+     */
+    uint256 ExtractMatches(std::vector<uint256> &vMatch, std::vector<unsigned int> &vnIndex);
+
+    /** Get number of transactions the merkle proof is indicating for cross-reference with
+     * local blockchain knowledge.
+     */
+    unsigned int GetNumTransactions() const { return nTransactions; };
+
+};
+
+
+/**
+ * Used to relay blocks as header + vector<merkle branch>
+ * to filtered nodes.
+ *
+ * NOTE: The class assumes that the given CBlock has *at least* 1 transaction. If the CBlock has 0 txs, it will hit an assertion.
+ */
+class CMerkleBlock
+{
+public:
+    /** Public only for unit testing */
+    CBlockHeader header;
+    CPartialMerkleTree txn;
+
+    /**
+     * Public only for unit testing and relay testing (not relayed).
+     *
+     * Used only when a bloom filter is specified to allow
+     * testing the transactions which matched the bloom filter.
+     */
+    std::vector<std::pair<unsigned int, uint256> > vMatchedTxn;
+
+    /**
+     * Create from a CBlock, filtering transactions according to filter
+     * Note that this will call IsRelevantAndUpdate on the filter for each transaction,
+     * thus the filter will likely be modified.
+     */
+    CMerkleBlock(const CBlock& block, CBloomFilter& filter) : CMerkleBlock(block, &filter, nullptr) { }
+
+    // Create from a CBlock, matching the txids in the set
+    CMerkleBlock(const CBlock& block, const std::set<uint256>& txids) : CMerkleBlock(block, nullptr, &txids) { }
+
+    CMerkleBlock() {}
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(header);
+        READWRITE(txn);
+    }
+
+private:
+    // Combined constructor to consolidate code
+    CMerkleBlock(const CBlock& block, CBloomFilter* filter, const std::set<uint256>* txids);
+};
+
+} // namespace Bitcoin
+} // namespace Sidechain
+
+#endif // BITCOIN_PRIMITIVES_BITCOIN_MERKLEBLOCK_H

src/primitives/bitcoin/transaction.cpp

@@ -0,0 +1,121 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <primitives/bitcoin/transaction.h>
+
+#include <hash.h>
+#include <tinyformat.h>
+#include <utilstrencodings.h>
+
+namespace Sidechain {
+namespace Bitcoin {
+
+std::string COutPoint::ToString() const
+{
+    return strprintf("COutPoint(%s, %u)", hash.ToString().substr(0,10), n);
+}
+
+CTxIn::CTxIn(COutPoint prevoutIn, CScript scriptSigIn, uint32_t nSequenceIn)
+{
+    prevout = prevoutIn;
+    scriptSig = scriptSigIn;
+    nSequence = nSequenceIn;
+}
+
+CTxIn::CTxIn(uint256 hashPrevTx, uint32_t nOut, CScript scriptSigIn, uint32_t nSequenceIn)
+{
+    prevout = COutPoint(hashPrevTx, nOut);
+    scriptSig = scriptSigIn;
+    nSequence = nSequenceIn;
+}
+
+std::string CTxIn::ToString() const
+{
+    std::string str;
+    str += "CTxIn(";
+    str += prevout.ToString();
+    if (prevout.IsNull())
+        str += strprintf(", coinbase %s", HexStr(scriptSig));
+    else
+        str += strprintf(", scriptSig=%s", HexStr(scriptSig).substr(0, 24));
+    if (nSequence != SEQUENCE_FINAL)
+        str += strprintf(", nSequence=%u", nSequence);
+    str += ")";
+    return str;
+}
+
+CTxOut::CTxOut(const CAmount& nValueIn, CScript scriptPubKeyIn)
+{
+    nValue = nValueIn;
+    scriptPubKey = scriptPubKeyIn;
+}
+
+std::string CTxOut::ToString() const
+{
+    return strprintf("CTxOut(nValue=%d.%08d, scriptPubKey=%s)", nValue / COIN, nValue % COIN, HexStr(scriptPubKey).substr(0, 30));
+}
+
+CMutableTransaction::CMutableTransaction() : nVersion(CTransaction::CURRENT_VERSION), nLockTime(0) {}
+CMutableTransaction::CMutableTransaction(const CTransaction& tx) : vin(tx.vin), vout(tx.vout), nVersion(tx.nVersion), nLockTime(tx.nLockTime) {}
+
+uint256 CMutableTransaction::GetHash() const
+{
+    return SerializeHash(*this, SER_GETHASH, SERIALIZE_TRANSACTION_NO_WITNESS);
+}
+
+uint256 CTransaction::ComputeHash() const
+{
+    return SerializeHash(*this, SER_GETHASH, SERIALIZE_TRANSACTION_NO_WITNESS);
+}
+
+uint256 CTransaction::ComputeWitnessHash() const
+{
+    if (!HasWitness()) {
+        return hash;
+    }
+    return SerializeHash(*this, SER_GETHASH, 0);
+}
+
+/* For backward compatibility, the hash is initialized to 0. TODO: remove the need for this default constructor entirely. */
+CTransaction::CTransaction() : vin(), vout(), nVersion(CTransaction::CURRENT_VERSION), nLockTime(0), hash{}, m_witness_hash{} {}
+CTransaction::CTransaction(const CMutableTransaction& tx) : vin(tx.vin), vout(tx.vout), nVersion(tx.nVersion), nLockTime(tx.nLockTime), hash{ComputeHash()}, m_witness_hash{ComputeWitnessHash()} {}
+CTransaction::CTransaction(CMutableTransaction&& tx) : vin(std::move(tx.vin)), vout(std::move(tx.vout)), nVersion(tx.nVersion), nLockTime(tx.nLockTime), hash{ComputeHash()}, m_witness_hash{ComputeWitnessHash()} {}
+
+CAmount CTransaction::GetValueOut() const
+{
+    CAmount nValueOut = 0;
+    for (const auto& tx_out : vout) {
+        nValueOut += tx_out.nValue;
+        if (!MoneyRange(tx_out.nValue) || !MoneyRange(nValueOut))
+            throw std::runtime_error(std::string(__func__) + ": value out of range");
+    }
+    return nValueOut;
+}
+
+unsigned int CTransaction::GetTotalSize() const
+{
+    return ::GetSerializeSize(*this, SER_NETWORK, PROTOCOL_VERSION);
+}
+
+std::string CTransaction::ToString() const
+{
+    std::string str;
+    str += strprintf("CTransaction(hash=%s, ver=%d, vin.size=%u, vout.size=%u, nLockTime=%u)\n",
+        GetHash().ToString().substr(0,10),
+        nVersion,
+        vin.size(),
+        vout.size(),
+        nLockTime);
+    for (const auto& tx_in : vin)
+        str += "    " + tx_in.ToString() + "\n";
+    for (const auto& tx_in : vin)
+        str += "    " + tx_in.scriptWitness.ToString() + "\n";
+    for (const auto& tx_out : vout)
+        str += "    " + tx_out.ToString() + "\n";
+    return str;
+}
+
+} // namespace Bitcoin
+} // namespace Sidechain

src/primitives/bitcoin/transaction.h

@@ -0,0 +1,412 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 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_PRIMITIVES_BITCOIN_TRANSACTION_H
+#define BITCOIN_PRIMITIVES_BITCOIN_TRANSACTION_H
+
+#include <stdint.h>
+#include <amount.h>
+#include <script/script.h>
+#include <serialize.h>
+#include <uint256.h>
+
+namespace Sidechain {
+namespace Bitcoin {
+
+static const int SERIALIZE_TRANSACTION_NO_WITNESS = 0x40000000;
+
+/** An outpoint - a combination of a transaction hash and an index n into its vout */
+class COutPoint
+{
+public:
+    uint256 hash;
+    uint32_t n;
+
+    COutPoint(): n((uint32_t) -1) { }
+    COutPoint(const uint256& hashIn, uint32_t nIn): hash(hashIn), n(nIn) { }
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(hash);
+        READWRITE(n);
+    }
+
+    void SetNull() { hash.SetNull(); n = (uint32_t) -1; }
+    bool IsNull() const { return (hash.IsNull() && n == (uint32_t) -1); }
+
+    friend bool operator<(const COutPoint& a, const COutPoint& b)
+    {
+        int cmp = a.hash.Compare(b.hash);
+        return cmp < 0 || (cmp == 0 && a.n < b.n);
+    }
+
+    friend bool operator==(const COutPoint& a, const COutPoint& b)
+    {
+        return (a.hash == b.hash && a.n == b.n);
+    }
+
+    friend bool operator!=(const COutPoint& a, const COutPoint& b)
+    {
+        return !(a == b);
+    }
+
+    std::string ToString() const;
+};
+
+/** An input of a transaction.  It contains the location of the previous
+ * transaction's output that it claims and a signature that matches the
+ * output's public key.
+ */
+class CTxIn
+{
+public:
+    COutPoint prevout;
+    CScript scriptSig;
+    uint32_t nSequence;
+    CScriptWitness scriptWitness; //! Only serialized through CTransaction
+
+    /* Setting nSequence to this value for every input in a transaction
+     * disables nLockTime. */
+    static const uint32_t SEQUENCE_FINAL = 0xffffffff;
+
+    /* Below flags apply in the context of BIP 68*/
+    /* If this flag set, CTxIn::nSequence is NOT interpreted as a
+     * relative lock-time. */
+    static const uint32_t SEQUENCE_LOCKTIME_DISABLE_FLAG = (1 << 31);
+
+    /* If CTxIn::nSequence encodes a relative lock-time and this flag
+     * is set, the relative lock-time has units of 512 seconds,
+     * otherwise it specifies blocks with a granularity of 1. */
+    static const uint32_t SEQUENCE_LOCKTIME_TYPE_FLAG = (1 << 22);
+
+    /* If CTxIn::nSequence encodes a relative lock-time, this mask is
+     * applied to extract that lock-time from the sequence field. */
+    static const uint32_t SEQUENCE_LOCKTIME_MASK = 0x0000ffff;
+
+    /* In order to use the same number of bits to encode roughly the
+     * same wall-clock duration, and because blocks are naturally
+     * limited to occur every 600s on average, the minimum granularity
+     * for time-based relative lock-time is fixed at 512 seconds.
+     * Converting from CTxIn::nSequence to seconds is performed by
+     * multiplying by 512 = 2^9, or equivalently shifting up by
+     * 9 bits. */
+    static const int SEQUENCE_LOCKTIME_GRANULARITY = 9;
+
+    CTxIn()
+    {
+        nSequence = SEQUENCE_FINAL;
+    }
+
+    explicit CTxIn(COutPoint prevoutIn, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=SEQUENCE_FINAL);
+    CTxIn(uint256 hashPrevTx, uint32_t nOut, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=SEQUENCE_FINAL);
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(prevout);
+        READWRITE(scriptSig);
+        READWRITE(nSequence);
+    }
+
+    friend bool operator==(const CTxIn& a, const CTxIn& b)
+    {
+        return (a.prevout   == b.prevout &&
+                a.scriptSig == b.scriptSig &&
+                a.nSequence == b.nSequence);
+    }
+
+    friend bool operator!=(const CTxIn& a, const CTxIn& b)
+    {
+        return !(a == b);
+    }
+
+    std::string ToString() const;
+};
+
+/** An output of a transaction.  It contains the public key that the next input
+ * must be able to sign with to claim it.
+ */
+class CTxOut
+{
+public:
+    CAmount nValue;
+    CScript scriptPubKey;
+
+    CTxOut()
+    {
+        SetNull();
+    }
+
+    CTxOut(const CAmount& nValueIn, CScript scriptPubKeyIn);
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(nValue);
+        READWRITE(scriptPubKey);
+    }
+
+    void SetNull()
+    {
+        nValue = -1;
+        scriptPubKey.clear();
+    }
+
+    bool IsNull() const
+    {
+        return (nValue == -1);
+    }
+
+    friend bool operator==(const CTxOut& a, const CTxOut& b)
+    {
+        return (a.nValue       == b.nValue &&
+                a.scriptPubKey == b.scriptPubKey);
+    }
+
+    friend bool operator!=(const CTxOut& a, const CTxOut& b)
+    {
+        return !(a == b);
+    }
+
+    std::string ToString() const;
+};
+
+struct CMutableTransaction;
+
+/**
+ * Basic transaction serialization format:
+ * - int32_t nVersion
+ * - std::vector<CTxIn> vin
+ * - std::vector<CTxOut> vout
+ * - uint32_t nLockTime
+ *
+ * Extended transaction serialization format:
+ * - int32_t nVersion
+ * - unsigned char dummy = 0x00
+ * - unsigned char flags (!= 0)
+ * - std::vector<CTxIn> vin
+ * - std::vector<CTxOut> vout
+ * - if (flags & 1):
+ *   - CTxWitness wit;
+ * - uint32_t nLockTime
+ */
+template<typename Stream, typename TxType>
+inline void UnserializeTransaction(TxType& tx, Stream& s) {
+    const bool fAllowWitness = !(s.GetVersion() & SERIALIZE_TRANSACTION_NO_WITNESS);
+
+    s >> tx.nVersion;
+    unsigned char flags = 0;
+    tx.vin.clear();
+    tx.vout.clear();
+    /* Try to read the vin. In case the dummy is there, this will be read as an empty vector. */
+    s >> tx.vin;
+    if (tx.vin.size() == 0 && fAllowWitness) {
+        /* We read a dummy or an empty vin. */
+        s >> flags;
+        if (flags != 0) {
+            s >> tx.vin;
+            s >> tx.vout;
+        }
+    } else {
+        /* We read a non-empty vin. Assume a normal vout follows. */
+        s >> tx.vout;
+    }
+    if ((flags & 1) && fAllowWitness) {
+        /* The witness flag is present, and we support witnesses. */
+        flags ^= 1;
+        for (size_t i = 0; i < tx.vin.size(); i++) {
+            s >> tx.vin[i].scriptWitness.stack;
+        }
+    }
+    if (flags) {
+        /* Unknown flag in the serialization */
+        throw std::ios_base::failure("Unknown transaction optional data");
+    }
+    s >> tx.nLockTime;
+}
+
+template<typename Stream, typename TxType>
+inline void SerializeTransaction(const TxType& tx, Stream& s) {
+    const bool fAllowWitness = !(s.GetVersion() & SERIALIZE_TRANSACTION_NO_WITNESS);
+
+    s << tx.nVersion;
+    unsigned char flags = 0;
+    // Consistency check
+    if (fAllowWitness) {
+        /* Check whether witnesses need to be serialized. */
+        if (tx.HasWitness()) {
+            flags |= 1;
+        }
+    }
+    if (flags) {
+        /* Use extended format in case witnesses are to be serialized. */
+        std::vector<CTxIn> vinDummy;
+        s << vinDummy;
+        s << flags;
+    }
+    s << tx.vin;
+    s << tx.vout;
+    if (flags & 1) {
+        for (size_t i = 0; i < tx.vin.size(); i++) {
+            s << tx.vin[i].scriptWitness.stack;
+        }
+    }
+    s << tx.nLockTime;
+}
+
+
+/** The basic transaction that is broadcasted on the network and contained in
+ * blocks.  A transaction can contain multiple inputs and outputs.
+ */
+class CTransaction
+{
+public:
+    // Default transaction version.
+    static const int32_t CURRENT_VERSION=2;
+
+    // Changing the default transaction version requires a two step process: first
+    // adapting relay policy by bumping MAX_STANDARD_VERSION, and then later date
+    // bumping the default CURRENT_VERSION at which point both CURRENT_VERSION and
+    // MAX_STANDARD_VERSION will be equal.
+    static const int32_t MAX_STANDARD_VERSION=2;
+
+    // The local variables are made const to prevent unintended modification
+    // without updating the cached hash value. However, CTransaction is not
+    // actually immutable; deserialization and assignment are implemented,
+    // and bypass the constness. This is safe, as they update the entire
+    // structure, including the hash.
+    const std::vector<CTxIn> vin;
+    const std::vector<CTxOut> vout;
+    const int32_t nVersion;
+    const uint32_t nLockTime;
+
+private:
+    /** Memory only. */
+    const uint256 hash;
+    const uint256 m_witness_hash;
+
+    uint256 ComputeHash() const;
+    uint256 ComputeWitnessHash() const;
+
+public:
+    /** Construct a CTransaction that qualifies as IsNull() */
+    CTransaction();
+
+    /** Convert a CMutableTransaction into a CTransaction. */
+    CTransaction(const CMutableTransaction &tx);
+    CTransaction(CMutableTransaction &&tx);
+
+    template <typename Stream>
+    inline void Serialize(Stream& s) const {
+        SerializeTransaction(*this, s);
+    }
+
+    /** This deserializing constructor is provided instead of an Unserialize method.
+     *  Unserialize is not possible, since it would require overwriting const fields. */
+    template <typename Stream>
+    CTransaction(deserialize_type, Stream& s) : CTransaction(CMutableTransaction(deserialize, s)) {}
+
+    bool IsNull() const {
+        return vin.empty() && vout.empty();
+    }
+
+    const uint256& GetHash() const { return hash; }
+    const uint256& GetWitnessHash() const { return m_witness_hash; };
+
+    // Return sum of txouts.
+    CAmount GetValueOut() const;
+    // GetValueIn() is a method on CCoinsViewCache, because
+    // inputs must be known to compute value in.
+
+    /**
+     * Get the total transaction size in bytes, including witness data.
+     * "Total Size" defined in BIP141 and BIP144.
+     * @return Total transaction size in bytes
+     */
+    unsigned int GetTotalSize() const;
+
+    bool IsCoinBase() const
+    {
+        return (vin.size() == 1 && vin[0].prevout.IsNull());
+    }
+
+    friend bool operator==(const CTransaction& a, const CTransaction& b)
+    {
+        return a.hash == b.hash;
+    }
+
+    friend bool operator!=(const CTransaction& a, const CTransaction& b)
+    {
+        return a.hash != b.hash;
+    }
+
+    std::string ToString() const;
+
+    bool HasWitness() const
+    {
+        for (size_t i = 0; i < vin.size(); i++) {
+            if (!vin[i].scriptWitness.IsNull()) {
+                return true;
+            }
+        }
+        return false;
+    }
+};
+
+/** A mutable version of CTransaction. */
+struct CMutableTransaction
+{
+    std::vector<CTxIn> vin;
+    std::vector<CTxOut> vout;
+    int32_t nVersion;
+    uint32_t nLockTime;
+
+    CMutableTransaction();
+    explicit CMutableTransaction(const CTransaction& tx);
+
+    template <typename Stream>
+    inline void Serialize(Stream& s) const {
+        SerializeTransaction(*this, s);
+    }
+
+
+    template <typename Stream>
+    inline void Unserialize(Stream& s) {
+        UnserializeTransaction(*this, s);
+    }
+
+    template <typename Stream>
+    CMutableTransaction(deserialize_type, Stream& s) {
+        Unserialize(s);
+    }
+
+    /** Compute the hash of this CMutableTransaction. This is computed on the
+     * fly, as opposed to GetHash() in CTransaction, which uses a cached result.
+     */
+    uint256 GetHash() const;
+
+    bool HasWitness() const
+    {
+        for (size_t i = 0; i < vin.size(); i++) {
+            if (!vin[i].scriptWitness.IsNull()) {
+                return true;
+            }
+        }
+        return false;
+    }
+};
+
+typedef std::shared_ptr<const CTransaction> CTransactionRef;
+static inline CTransactionRef MakeTransactionRef() { return std::make_shared<const CTransaction>(); }
+template <typename Tx> static inline CTransactionRef MakeTransactionRef(Tx&& txIn) { return std::make_shared<const CTransaction>(std::forward<Tx>(txIn)); }
+
+} // namespace Bitcoin
+} // namespace Sidechain
+
+#endif // BITCOIN_PRIMITIVES_BITCOIN_TRANSACTION_H