Rename script.h/.cpp to scriptutils.h/.cpp (plus remove duplicated includes)

1 files changed, 815 insertions, 0 deletions

diff --git a/src/scriptutils.h b/src/scriptutils.h
new file mode 100644
index 0000000000..44f18483c3
--- /dev/null
+++ b/src/scriptutils.h
@@ -0,0 +1,815 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2013 The Bitcoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef H_BITCOIN_SCRIPTUTILS
+#define H_BITCOIN_SCRIPTUTILS
+
+#include "key.h"
+#include "utilstrencodings.h"
+#include "tinyformat.h"
+
+#include <stdexcept>
+#include <stdint.h>
+#include <string>
+#include <vector>
+
+#include <boost/variant.hpp>
+
+class CKeyStore;
+class CTransaction;
+struct CMutableTransaction;
+
+static const unsigned int MAX_SCRIPT_ELEMENT_SIZE = 520; // bytes
+static const unsigned int MAX_OP_RETURN_RELAY = 40;      // bytes
+
+class scriptnum_error : public std::runtime_error
+{
+public:
+    explicit scriptnum_error(const std::string& str) : std::runtime_error(str) {}
+};
+
+class CScriptNum
+{
+// Numeric opcodes (OP_1ADD, etc) are restricted to operating on 4-byte integers.
+// The semantics are subtle, though: operands must be in the range [-2^31 +1...2^31 -1],
+// but results may overflow (and are valid as long as they are not used in a subsequent
+// numeric operation). CScriptNum enforces those semantics by storing results as
+// an int64 and allowing out-of-range values to be returned as a vector of bytes but
+// throwing an exception if arithmetic is done or the result is interpreted as an integer.
+public:
+
+    explicit CScriptNum(const int64_t& n)
+    {
+        m_value = n;
+    }
+
+    explicit CScriptNum(const std::vector<unsigned char>& vch)
+    {
+        if (vch.size() > nMaxNumSize)
+            throw scriptnum_error("CScriptNum(const std::vector<unsigned char>&) : overflow");
+        m_value = set_vch(vch);
+    }
+
+    inline bool operator==(const int64_t& rhs) const    { return m_value == rhs; }
+    inline bool operator!=(const int64_t& rhs) const    { return m_value != rhs; }
+    inline bool operator<=(const int64_t& rhs) const    { return m_value <= rhs; }
+    inline bool operator< (const int64_t& rhs) const    { return m_value <  rhs; }
+    inline bool operator>=(const int64_t& rhs) const    { return m_value >= rhs; }
+    inline bool operator> (const int64_t& rhs) const    { return m_value >  rhs; }
+
+    inline bool operator==(const CScriptNum& rhs) const { return operator==(rhs.m_value); }
+    inline bool operator!=(const CScriptNum& rhs) const { return operator!=(rhs.m_value); }
+    inline bool operator<=(const CScriptNum& rhs) const { return operator<=(rhs.m_value); }
+    inline bool operator< (const CScriptNum& rhs) const { return operator< (rhs.m_value); }
+    inline bool operator>=(const CScriptNum& rhs) const { return operator>=(rhs.m_value); }
+    inline bool operator> (const CScriptNum& rhs) const { return operator> (rhs.m_value); }
+
+    inline CScriptNum operator+(   const int64_t& rhs)    const { return CScriptNum(m_value + rhs);}
+    inline CScriptNum operator-(   const int64_t& rhs)    const { return CScriptNum(m_value - rhs);}
+    inline CScriptNum operator+(   const CScriptNum& rhs) const { return operator+(rhs.m_value);   }
+    inline CScriptNum operator-(   const CScriptNum& rhs) const { return operator-(rhs.m_value);   }
+
+    inline CScriptNum& operator+=( const CScriptNum& rhs)       { return operator+=(rhs.m_value);  }
+    inline CScriptNum& operator-=( const CScriptNum& rhs)       { return operator-=(rhs.m_value);  }
+
+    inline CScriptNum operator-()                         const
+    {
+        assert(m_value != std::numeric_limits<int64_t>::min());
+        return CScriptNum(-m_value);
+    }
+
+    inline CScriptNum& operator=( const int64_t& rhs)
+    {
+        m_value = rhs;
+        return *this;
+    }
+
+    inline CScriptNum& operator+=( const int64_t& rhs)
+    {
+        assert(rhs == 0 || (rhs > 0 && m_value <= std::numeric_limits<int64_t>::max() - rhs) ||
+                           (rhs < 0 && m_value >= std::numeric_limits<int64_t>::min() - rhs));
+        m_value += rhs;
+        return *this;
+    }
+
+    inline CScriptNum& operator-=( const int64_t& rhs)
+    {
+        assert(rhs == 0 || (rhs > 0 && m_value >= std::numeric_limits<int64_t>::min() + rhs) ||
+                           (rhs < 0 && m_value <= std::numeric_limits<int64_t>::max() + rhs));
+        m_value -= rhs;
+        return *this;
+    }
+
+    int getint() const
+    {
+        if (m_value > std::numeric_limits<int>::max())
+            return std::numeric_limits<int>::max();
+        else if (m_value < std::numeric_limits<int>::min())
+            return std::numeric_limits<int>::min();
+        return m_value;
+    }
+
+    std::vector<unsigned char> getvch() const
+    {
+        return serialize(m_value);
+    }
+
+    static std::vector<unsigned char> serialize(const int64_t& value)
+    {
+        if(value == 0)
+            return std::vector<unsigned char>();
+
+        std::vector<unsigned char> result;
+        const bool neg = value < 0;
+        uint64_t absvalue = neg ? -value : value;
+
+        while(absvalue)
+        {
+            result.push_back(absvalue & 0xff);
+            absvalue >>= 8;
+        }
+
+
+//    - If the most significant byte is >= 0x80 and the value is positive, push a
+//    new zero-byte to make the significant byte < 0x80 again.
+
+//    - If the most significant byte is >= 0x80 and the value is negative, push a
+//    new 0x80 byte that will be popped off when converting to an integral.
+
+//    - If the most significant byte is < 0x80 and the value is negative, add
+//    0x80 to it, since it will be subtracted and interpreted as a negative when
+//    converting to an integral.
+
+        if (result.back() & 0x80)
+            result.push_back(neg ? 0x80 : 0);
+        else if (neg)
+            result.back() |= 0x80;
+
+        return result;
+    }
+
+    static const size_t nMaxNumSize = 4;
+
+private:
+    static int64_t set_vch(const std::vector<unsigned char>& vch)
+    {
+      if (vch.empty())
+          return 0;
+
+      int64_t result = 0;
+      for (size_t i = 0; i != vch.size(); ++i)
+          result |= static_cast<int64_t>(vch[i]) << 8*i;
+
+      // If the input vector's most significant byte is 0x80, remove it from
+      // the result's msb and return a negative.
+      if (vch.back() & 0x80)
+          return -(result & ~(0x80ULL << (8 * (vch.size() - 1))));
+
+      return result;
+    }
+
+    int64_t m_value;
+};
+
+/** Signature hash types/flags */
+enum
+{
+    SIGHASH_ALL = 1,
+    SIGHASH_NONE = 2,
+    SIGHASH_SINGLE = 3,
+    SIGHASH_ANYONECANPAY = 0x80,
+};
+
+/** Script verification flags */
+enum
+{
+    SCRIPT_VERIFY_NONE      = 0,
+    SCRIPT_VERIFY_P2SH      = (1U << 0), // evaluate P2SH (BIP16) subscripts
+    SCRIPT_VERIFY_STRICTENC = (1U << 1), // enforce strict conformance to DER and SEC2 for signatures and pubkeys
+    SCRIPT_VERIFY_LOW_S     = (1U << 2), // enforce low S values (<n/2) in signatures (depends on STRICTENC)
+    SCRIPT_VERIFY_NOCACHE   = (1U << 3), // do not store results in signature cache (but do query it)
+    SCRIPT_VERIFY_NULLDUMMY = (1U << 4), // verify dummy stack item consumed by CHECKMULTISIG is of zero-length
+};
+
+/** IsMine() return codes */
+enum isminetype
+{
+    ISMINE_NO = 0,
+    ISMINE_WATCH_ONLY = 1,
+    ISMINE_SPENDABLE = 2,
+    ISMINE_ALL = ISMINE_WATCH_ONLY | ISMINE_SPENDABLE
+};
+/** used for bitflags of isminetype */
+typedef uint8_t isminefilter;
+
+// Mandatory script verification flags that all new blocks must comply with for
+// them to be valid. (but old blocks may not comply with) Currently just P2SH,
+// but in the future other flags may be added, such as a soft-fork to enforce
+// strict DER encoding.
+//
+// Failing one of these tests may trigger a DoS ban - see CheckInputs() for
+// details.
+static const unsigned int MANDATORY_SCRIPT_VERIFY_FLAGS = SCRIPT_VERIFY_P2SH;
+
+// Standard script verification flags that standard transactions will comply
+// with. However scripts violating these flags may still be present in valid
+// blocks and we must accept those blocks.
+static const unsigned int STANDARD_SCRIPT_VERIFY_FLAGS = MANDATORY_SCRIPT_VERIFY_FLAGS |
+                                                         SCRIPT_VERIFY_STRICTENC |
+                                                         SCRIPT_VERIFY_NULLDUMMY;
+
+// For convenience, standard but not mandatory verify flags.
+static const unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS;
+
+enum txnouttype
+{
+    TX_NONSTANDARD,
+    // 'standard' transaction types:
+    TX_PUBKEY,
+    TX_PUBKEYHASH,
+    TX_SCRIPTHASH,
+    TX_MULTISIG,
+    TX_NULL_DATA,
+};
+
+class CNoDestination {
+public:
+    friend bool operator==(const CNoDestination &a, const CNoDestination &b) { return true; }
+    friend bool operator<(const CNoDestination &a, const CNoDestination &b) { return true; }
+};
+
+/** A txout script template with a specific destination. It is either:
+ *  * CNoDestination: no destination set
+ *  * CKeyID: TX_PUBKEYHASH destination
+ *  * CScriptID: TX_SCRIPTHASH destination
+ *  A CTxDestination is the internal data type encoded in a CBitcoinAddress
+ */
+typedef boost::variant<CNoDestination, CKeyID, CScriptID> CTxDestination;
+
+const char* GetTxnOutputType(txnouttype t);
+
+/** Script opcodes */
+enum opcodetype
+{
+    // push value
+    OP_0 = 0x00,
+    OP_FALSE = OP_0,
+    OP_PUSHDATA1 = 0x4c,
+    OP_PUSHDATA2 = 0x4d,
+    OP_PUSHDATA4 = 0x4e,
+    OP_1NEGATE = 0x4f,
+    OP_RESERVED = 0x50,
+    OP_1 = 0x51,
+    OP_TRUE=OP_1,
+    OP_2 = 0x52,
+    OP_3 = 0x53,
+    OP_4 = 0x54,
+    OP_5 = 0x55,
+    OP_6 = 0x56,
+    OP_7 = 0x57,
+    OP_8 = 0x58,
+    OP_9 = 0x59,
+    OP_10 = 0x5a,
+    OP_11 = 0x5b,
+    OP_12 = 0x5c,
+    OP_13 = 0x5d,
+    OP_14 = 0x5e,
+    OP_15 = 0x5f,
+    OP_16 = 0x60,
+
+    // control
+    OP_NOP = 0x61,
+    OP_VER = 0x62,
+    OP_IF = 0x63,
+    OP_NOTIF = 0x64,
+    OP_VERIF = 0x65,
+    OP_VERNOTIF = 0x66,
+    OP_ELSE = 0x67,
+    OP_ENDIF = 0x68,
+    OP_VERIFY = 0x69,
+    OP_RETURN = 0x6a,
+
+    // stack ops
+    OP_TOALTSTACK = 0x6b,
+    OP_FROMALTSTACK = 0x6c,
+    OP_2DROP = 0x6d,
+    OP_2DUP = 0x6e,
+    OP_3DUP = 0x6f,
+    OP_2OVER = 0x70,
+    OP_2ROT = 0x71,
+    OP_2SWAP = 0x72,
+    OP_IFDUP = 0x73,
+    OP_DEPTH = 0x74,
+    OP_DROP = 0x75,
+    OP_DUP = 0x76,
+    OP_NIP = 0x77,
+    OP_OVER = 0x78,
+    OP_PICK = 0x79,
+    OP_ROLL = 0x7a,
+    OP_ROT = 0x7b,
+    OP_SWAP = 0x7c,
+    OP_TUCK = 0x7d,
+
+    // splice ops
+    OP_CAT = 0x7e,
+    OP_SUBSTR = 0x7f,
+    OP_LEFT = 0x80,
+    OP_RIGHT = 0x81,
+    OP_SIZE = 0x82,
+
+    // bit logic
+    OP_INVERT = 0x83,
+    OP_AND = 0x84,
+    OP_OR = 0x85,
+    OP_XOR = 0x86,
+    OP_EQUAL = 0x87,
+    OP_EQUALVERIFY = 0x88,
+    OP_RESERVED1 = 0x89,
+    OP_RESERVED2 = 0x8a,
+
+    // numeric
+    OP_1ADD = 0x8b,
+    OP_1SUB = 0x8c,
+    OP_2MUL = 0x8d,
+    OP_2DIV = 0x8e,
+    OP_NEGATE = 0x8f,
+    OP_ABS = 0x90,
+    OP_NOT = 0x91,
+    OP_0NOTEQUAL = 0x92,
+
+    OP_ADD = 0x93,
+    OP_SUB = 0x94,
+    OP_MUL = 0x95,
+    OP_DIV = 0x96,
+    OP_MOD = 0x97,
+    OP_LSHIFT = 0x98,
+    OP_RSHIFT = 0x99,
+
+    OP_BOOLAND = 0x9a,
+    OP_BOOLOR = 0x9b,
+    OP_NUMEQUAL = 0x9c,
+    OP_NUMEQUALVERIFY = 0x9d,
+    OP_NUMNOTEQUAL = 0x9e,
+    OP_LESSTHAN = 0x9f,
+    OP_GREATERTHAN = 0xa0,
+    OP_LESSTHANOREQUAL = 0xa1,
+    OP_GREATERTHANOREQUAL = 0xa2,
+    OP_MIN = 0xa3,
+    OP_MAX = 0xa4,
+
+    OP_WITHIN = 0xa5,
+
+    // crypto
+    OP_RIPEMD160 = 0xa6,
+    OP_SHA1 = 0xa7,
+    OP_SHA256 = 0xa8,
+    OP_HASH160 = 0xa9,
+    OP_HASH256 = 0xaa,
+    OP_CODESEPARATOR = 0xab,
+    OP_CHECKSIG = 0xac,
+    OP_CHECKSIGVERIFY = 0xad,
+    OP_CHECKMULTISIG = 0xae,
+    OP_CHECKMULTISIGVERIFY = 0xaf,
+
+    // expansion
+    OP_NOP1 = 0xb0,
+    OP_NOP2 = 0xb1,
+    OP_NOP3 = 0xb2,
+    OP_NOP4 = 0xb3,
+    OP_NOP5 = 0xb4,
+    OP_NOP6 = 0xb5,
+    OP_NOP7 = 0xb6,
+    OP_NOP8 = 0xb7,
+    OP_NOP9 = 0xb8,
+    OP_NOP10 = 0xb9,
+
+
+
+    // template matching params
+    OP_SMALLDATA = 0xf9,
+    OP_SMALLINTEGER = 0xfa,
+    OP_PUBKEYS = 0xfb,
+    OP_PUBKEYHASH = 0xfd,
+    OP_PUBKEY = 0xfe,
+
+    OP_INVALIDOPCODE = 0xff,
+};
+
+const char* GetOpName(opcodetype opcode);
+
+
+
+inline std::string ValueString(const std::vector<unsigned char>& vch)
+{
+    if (vch.size() <= 4)
+        return strprintf("%d", CScriptNum(vch).getint());
+    else
+        return HexStr(vch);
+}
+
+/** Serialized script, used inside transaction inputs and outputs */
+class CScript : public std::vector<unsigned char>
+{
+protected:
+    CScript& push_int64(int64_t n)
+    {
+        if (n == -1 || (n >= 1 && n <= 16))
+        {
+            push_back(n + (OP_1 - 1));
+        }
+        else
+        {
+            *this << CScriptNum::serialize(n);
+        }
+        return *this;
+    }
+public:
+    CScript() { }
+    CScript(const CScript& b) : std::vector<unsigned char>(b.begin(), b.end()) { }
+    CScript(const_iterator pbegin, const_iterator pend) : std::vector<unsigned char>(pbegin, pend) { }
+#ifndef _MSC_VER
+    CScript(const unsigned char* pbegin, const unsigned char* pend) : std::vector<unsigned char>(pbegin, pend) { }
+#endif
+
+    CScript& operator+=(const CScript& b)
+    {
+        insert(end(), b.begin(), b.end());
+        return *this;
+    }
+
+    friend CScript operator+(const CScript& a, const CScript& b)
+    {
+        CScript ret = a;
+        ret += b;
+        return ret;
+    }
+
+
+    CScript(int64_t b)        { operator<<(b); }
+
+    explicit CScript(opcodetype b)     { operator<<(b); }
+    explicit CScript(const uint256& b) { operator<<(b); }
+    explicit CScript(const CScriptNum& b) { operator<<(b); }
+    explicit CScript(const std::vector<unsigned char>& b) { operator<<(b); }
+
+
+    CScript& operator<<(int64_t b) { return push_int64(b); }
+
+    CScript& operator<<(opcodetype opcode)
+    {
+        if (opcode < 0 || opcode > 0xff)
+            throw std::runtime_error("CScript::operator<<() : invalid opcode");
+        insert(end(), (unsigned char)opcode);
+        return *this;
+    }
+
+    CScript& operator<<(const uint160& b)
+    {
+        insert(end(), sizeof(b));
+        insert(end(), (unsigned char*)&b, (unsigned char*)&b + sizeof(b));
+        return *this;
+    }
+
+    CScript& operator<<(const uint256& b)
+    {
+        insert(end(), sizeof(b));
+        insert(end(), (unsigned char*)&b, (unsigned char*)&b + sizeof(b));
+        return *this;
+    }
+
+    CScript& operator<<(const CPubKey& key)
+    {
+        assert(key.size() < OP_PUSHDATA1);
+        insert(end(), (unsigned char)key.size());
+        insert(end(), key.begin(), key.end());
+        return *this;
+    }
+
+    CScript& operator<<(const CScriptNum& b)
+    {
+        *this << b.getvch();
+        return *this;
+    }
+
+    CScript& operator<<(const std::vector<unsigned char>& b)
+    {
+        if (b.size() < OP_PUSHDATA1)
+        {
+            insert(end(), (unsigned char)b.size());
+        }
+        else if (b.size() <= 0xff)
+        {
+            insert(end(), OP_PUSHDATA1);
+            insert(end(), (unsigned char)b.size());
+        }
+        else if (b.size() <= 0xffff)
+        {
+            insert(end(), OP_PUSHDATA2);
+            unsigned short nSize = b.size();
+            insert(end(), (unsigned char*)&nSize, (unsigned char*)&nSize + sizeof(nSize));
+        }
+        else
+        {
+            insert(end(), OP_PUSHDATA4);
+            unsigned int nSize = b.size();
+            insert(end(), (unsigned char*)&nSize, (unsigned char*)&nSize + sizeof(nSize));
+        }
+        insert(end(), b.begin(), b.end());
+        return *this;
+    }
+
+    CScript& operator<<(const CScript& b)
+    {
+        // I'm not sure if this should push the script or concatenate scripts.
+        // If there's ever a use for pushing a script onto a script, delete this member fn
+        assert(!"Warning: Pushing a CScript onto a CScript with << is probably not intended, use + to concatenate!");
+        return *this;
+    }
+
+
+    bool GetOp(iterator& pc, opcodetype& opcodeRet, std::vector<unsigned char>& vchRet)
+    {
+         // Wrapper so it can be called with either iterator or const_iterator
+         const_iterator pc2 = pc;
+         bool fRet = GetOp2(pc2, opcodeRet, &vchRet);
+         pc = begin() + (pc2 - begin());
+         return fRet;
+    }
+
+    bool GetOp(iterator& pc, opcodetype& opcodeRet)
+    {
+         const_iterator pc2 = pc;
+         bool fRet = GetOp2(pc2, opcodeRet, NULL);
+         pc = begin() + (pc2 - begin());
+         return fRet;
+    }
+
+    bool GetOp(const_iterator& pc, opcodetype& opcodeRet, std::vector<unsigned char>& vchRet) const
+    {
+        return GetOp2(pc, opcodeRet, &vchRet);
+    }
+
+    bool GetOp(const_iterator& pc, opcodetype& opcodeRet) const
+    {
+        return GetOp2(pc, opcodeRet, NULL);
+    }
+
+    bool GetOp2(const_iterator& pc, opcodetype& opcodeRet, std::vector<unsigned char>* pvchRet) const
+    {
+        opcodeRet = OP_INVALIDOPCODE;
+        if (pvchRet)
+            pvchRet->clear();
+        if (pc >= end())
+            return false;
+
+        // Read instruction
+        if (end() - pc < 1)
+            return false;
+        unsigned int opcode = *pc++;
+
+        // Immediate operand
+        if (opcode <= OP_PUSHDATA4)
+        {
+            unsigned int nSize = 0;
+            if (opcode < OP_PUSHDATA1)
+            {
+                nSize = opcode;
+            }
+            else if (opcode == OP_PUSHDATA1)
+            {
+                if (end() - pc < 1)
+                    return false;
+                nSize = *pc++;
+            }
+            else if (opcode == OP_PUSHDATA2)
+            {
+                if (end() - pc < 2)
+                    return false;
+                nSize = 0;
+                memcpy(&nSize, &pc[0], 2);
+                pc += 2;
+            }
+            else if (opcode == OP_PUSHDATA4)
+            {
+                if (end() - pc < 4)
+                    return false;
+                memcpy(&nSize, &pc[0], 4);
+                pc += 4;
+            }
+            if (end() - pc < 0 || (unsigned int)(end() - pc) < nSize)
+                return false;
+            if (pvchRet)
+                pvchRet->assign(pc, pc + nSize);
+            pc += nSize;
+        }
+
+        opcodeRet = (opcodetype)opcode;
+        return true;
+    }
+
+    // Encode/decode small integers:
+    static int DecodeOP_N(opcodetype opcode)
+    {
+        if (opcode == OP_0)
+            return 0;
+        assert(opcode >= OP_1 && opcode <= OP_16);
+        return (int)opcode - (int)(OP_1 - 1);
+    }
+    static opcodetype EncodeOP_N(int n)
+    {
+        assert(n >= 0 && n <= 16);
+        if (n == 0)
+            return OP_0;
+        return (opcodetype)(OP_1+n-1);
+    }
+
+    int FindAndDelete(const CScript& b)
+    {
+        int nFound = 0;
+        if (b.empty())
+            return nFound;
+        iterator pc = begin();
+        opcodetype opcode;
+        do
+        {
+            while (end() - pc >= (long)b.size() && memcmp(&pc[0], &b[0], b.size()) == 0)
+            {
+                erase(pc, pc + b.size());
+                ++nFound;
+            }
+        }
+        while (GetOp(pc, opcode));
+        return nFound;
+    }
+    int Find(opcodetype op) const
+    {
+        int nFound = 0;
+        opcodetype opcode;
+        for (const_iterator pc = begin(); pc != end() && GetOp(pc, opcode);)
+            if (opcode == op)
+                ++nFound;
+        return nFound;
+    }
+
+    // Pre-version-0.6, Bitcoin always counted CHECKMULTISIGs
+    // as 20 sigops. With pay-to-script-hash, that changed:
+    // CHECKMULTISIGs serialized in scriptSigs are
+    // counted more accurately, assuming they are of the form
+    //  ... OP_N CHECKMULTISIG ...
+    unsigned int GetSigOpCount(bool fAccurate) const;
+
+    // Accurately count sigOps, including sigOps in
+    // pay-to-script-hash transactions:
+    unsigned int GetSigOpCount(const CScript& scriptSig) const;
+
+    bool IsPayToScriptHash() const;
+
+    // Called by IsStandardTx and P2SH VerifyScript (which makes it consensus-critical).
+    bool IsPushOnly() const;
+
+    // Called by IsStandardTx.
+    bool HasCanonicalPushes() const;
+
+    // Returns whether the script is guaranteed to fail at execution,
+    // regardless of the initial stack. This allows outputs to be pruned
+    // instantly when entering the UTXO set.
+    bool IsUnspendable() const
+    {
+        return (size() > 0 && *begin() == OP_RETURN);
+    }
+
+    void SetDestination(const CTxDestination& address);
+    void SetMultisig(int nRequired, const std::vector<CPubKey>& keys);
+
+    std::string ToString() const
+    {
+        std::string str;
+        opcodetype opcode;
+        std::vector<unsigned char> vch;
+        const_iterator pc = begin();
+        while (pc < end())
+        {
+            if (!str.empty())
+                str += " ";
+            if (!GetOp(pc, opcode, vch))
+            {
+                str += "[error]";
+                return str;
+            }
+            if (0 <= opcode && opcode <= OP_PUSHDATA4)
+                str += ValueString(vch);
+            else
+                str += GetOpName(opcode);
+        }
+        return str;
+    }
+
+    CScriptID GetID() const
+    {
+        return CScriptID(Hash160(*this));
+    }
+
+    void clear()
+    {
+        // The default std::vector::clear() does not release memory.
+        std::vector<unsigned char>().swap(*this);
+    }
+};
+
+/** Compact serializer for scripts.
+ *
+ *  It detects common cases and encodes them much more efficiently.
+ *  3 special cases are defined:
+ *  * Pay to pubkey hash (encoded as 21 bytes)
+ *  * Pay to script hash (encoded as 21 bytes)
+ *  * Pay to pubkey starting with 0x02, 0x03 or 0x04 (encoded as 33 bytes)
+ *
+ *  Other scripts up to 121 bytes require 1 byte + script length. Above
+ *  that, scripts up to 16505 bytes require 2 bytes + script length.
+ */
+class CScriptCompressor
+{
+private:
+    // make this static for now (there are only 6 special scripts defined)
+    // this can potentially be extended together with a new nVersion for
+    // transactions, in which case this value becomes dependent on nVersion
+    // and nHeight of the enclosing transaction.
+    static const unsigned int nSpecialScripts = 6;
+
+    CScript &script;
+protected:
+    // These check for scripts for which a special case with a shorter encoding is defined.
+    // They are implemented separately from the CScript test, as these test for exact byte
+    // sequence correspondences, and are more strict. For example, IsToPubKey also verifies
+    // whether the public key is valid (as invalid ones cannot be represented in compressed
+    // form).
+    bool IsToKeyID(CKeyID &hash) const;
+    bool IsToScriptID(CScriptID &hash) const;
+    bool IsToPubKey(CPubKey &pubkey) const;
+
+    bool Compress(std::vector<unsigned char> &out) const;
+    unsigned int GetSpecialSize(unsigned int nSize) const;
+    bool Decompress(unsigned int nSize, const std::vector<unsigned char> &out);
+public:
+    CScriptCompressor(CScript &scriptIn) : script(scriptIn) { }
+
+    unsigned int GetSerializeSize(int nType, int nVersion) const {
+        std::vector<unsigned char> compr;
+        if (Compress(compr))
+            return compr.size();
+        unsigned int nSize = script.size() + nSpecialScripts;
+        return script.size() + VARINT(nSize).GetSerializeSize(nType, nVersion);
+    }
+
+    template<typename Stream>
+    void Serialize(Stream &s, int nType, int nVersion) const {
+        std::vector<unsigned char> compr;
+        if (Compress(compr)) {
+            s << CFlatData(compr);
+            return;
+        }
+        unsigned int nSize = script.size() + nSpecialScripts;
+        s << VARINT(nSize);
+        s << CFlatData(script);
+    }
+
+    template<typename Stream>
+    void Unserialize(Stream &s, int nType, int nVersion) {
+        unsigned int nSize = 0;
+        s >> VARINT(nSize);
+        if (nSize < nSpecialScripts) {
+            std::vector<unsigned char> vch(GetSpecialSize(nSize), 0x00);
+            s >> REF(CFlatData(vch));
+            Decompress(nSize, vch);
+            return;
+        }
+        nSize -= nSpecialScripts;
+        script.resize(nSize);
+        s >> REF(CFlatData(script));
+    }
+};
+
+bool IsCanonicalPubKey(const std::vector<unsigned char> &vchPubKey, unsigned int flags);
+bool IsCanonicalSignature(const std::vector<unsigned char> &vchSig, unsigned int flags);
+
+bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript& script, const CTransaction& txTo, unsigned int nIn, unsigned int flags, int nHashType);
+uint256 SignatureHash(const CScript &scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType);
+bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<std::vector<unsigned char> >& vSolutionsRet);
+int ScriptSigArgsExpected(txnouttype t, const std::vector<std::vector<unsigned char> >& vSolutions);
+bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType);
+isminetype IsMine(const CKeyStore& keystore, const CScript& scriptPubKey);
+isminetype IsMine(const CKeyStore& keystore, const CTxDestination& dest);
+void ExtractAffectedKeys(const CKeyStore &keystore, const CScript& scriptPubKey, std::vector<CKeyID> &vKeys);
+bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet);
+bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet);
+bool SignSignature(const CKeyStore& keystore, const CScript& fromPubKey, CMutableTransaction& txTo, unsigned int nIn, int nHashType=SIGHASH_ALL);
+bool SignSignature(const CKeyStore& keystore, const CTransaction& txFrom, CMutableTransaction& txTo, unsigned int nIn, int nHashType=SIGHASH_ALL);
+bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, const CTransaction& txTo, unsigned int nIn, unsigned int flags, int nHashType);
+
+// Given two sets of signatures for scriptPubKey, possibly with OP_0 placeholders,
+// combine them intelligently and return the result.
+CScript CombineSignatures(CScript scriptPubKey, const CTransaction& txTo, unsigned int nIn, const CScript& scriptSig1, const CScript& scriptSig2);
+
+#endif // H_BITCOIN_SCRIPT