dogecoin/src/script/standard.h
Patrick Lodder 1b8848d5f3 Make low-s verification mandatory for standard script verification
This change makes a node only accept transactions with low-s
signature encoding for relay and mining, but allows transactions
with high-s signature encoding in mined blocks (no blocks will
be rejected)

Pros:
- If deployed by all miners, this will eliminate this particular
  malleability attack.
- There is no impact on consensus

Cons:
- Wallets that do not implement low-s signature encoding will
  see their transactions be rejected by growing numbers of peers
  and ultimately not be able to get any transaction mined.

Follow ups:
- Eventually, this verification needs to be confirmed through a
  consensus rule (enforcement of BIP62)
2015-10-06 17:51:59 +02:00

97 lines
3.7 KiB
C++

// 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 = 80; //! 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, 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_DERSIG |
SCRIPT_VERIFY_STRICTENC |
SCRIPT_VERIFY_MINIMALDATA |
SCRIPT_VERIFY_NULLDUMMY |
SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS |
SCRIPT_VERIFY_CLEANSTACK |
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_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);
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 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