hush3/src/script/standard.h

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2014 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef BITCOIN_SCRIPT_STANDARD_H
#define BITCOIN_SCRIPT_STANDARD_H

#include "script/interpreter.h"
#include "uint256.h"

#include <boost/variant.hpp>

#include <stdint.h>

class CKeyID;
class CScript;

/** A reference to a CScript: the Hash160 of its serialization (see script.h) */
class CScriptID : public uint160
{
public:
    CScriptID() : uint160() {}
    CScriptID(const CScript& in);
    CScriptID(const uint160& in) : uint160(in) {}
};

static const unsigned int MAX_OP_RETURN_RELAY = 8192;      //! bytes
extern unsigned nMaxDatacarrierBytes;

/**
 * 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.
 *
 * 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_DERSIG is always enforced
                                                         SCRIPT_VERIFY_STRICTENC |
                                                         SCRIPT_VERIFY_MINIMALDATA |
                                                         SCRIPT_VERIFY_NULLDUMMY |
                                                         SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS |
                                                         SCRIPT_VERIFY_CLEANSTACK |
                                                         SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY |
                                                         SCRIPT_VERIFY_LOW_S;

/** 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_CRYPTOCONDITION,
    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 bitcoin address
 */
typedef boost::variant<CNoDestination, CPubKey, CKeyID, CScriptID> CTxDestination;

class COptCCParams
{
    public:
        static const uint8_t VERSION = 1;

        uint8_t version;
        uint8_t evalCode;
        uint8_t n, m; // for n of m sigs required, m addresses for sigs will follow

        COptCCParams() : version(0), evalCode(0), n(0), m(0) {}

        COptCCParams(uint8_t ver, uint8_t code, uint8_t _n, uint8_t _m) : version(ver), evalCode(code), n(_n), m(_m) {}

        COptCCParams(std::vector<unsigned char> &vch)
        {
            version = 0;
            if (vch.size() == 4)
            {
                version = vch[0];
                evalCode = vch[1];
                n = vch[2];
                m = vch[3];
                if (version != VERSION && n == 1 && (m == 1 || m == 2))
                {
                    // we only support one version, and 1 of 1 or 1 of 2 now, so set invalid
                    version = 0;
                }
            }
        }

        bool IsValid() { return version != 0; }

        std::vector<unsigned char> AsVector()
        {
            std::vector<unsigned char> vch = std::vector<unsigned char>({version, evalCode, n, m});
        }
};

/** Check whether a CTxDestination is a CNoDestination. */
bool IsValidDestination(const CTxDestination& dest);

const char* GetTxnOutputType(txnouttype t);

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);
bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet, bool returnPubKey=false);
bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet);

CScript GetScriptForDestination(const CTxDestination& dest);
CScript GetScriptForMultisig(int nRequired, const std::vector<CPubKey>& keys);

#endif // BITCOIN_SCRIPT_STANDARD_H