policy.cpp File Reference

#include "policy/policy.h"
#include "validation.h"
#include "tinyformat.h"
#include "util.h"
#include "utilstrencodings.h"
#include <boost/foreach.hpp>

Go to the source code of this file.

Functions
bool	IsStandard (const CScript &scriptPubKey, txnouttype &whichType)
bool	IsStandardTx (const CTransaction &tx, std::string &reason)
bool	AreInputsStandard (const CTransaction &tx, const CCoinsViewCache &mapInputs)

Function Documentation

AreInputsStandard()

bool AreInputsStandard	(	const CTransaction &	tx,
		const CCoinsViewCache &	mapInputs
	)

Check for standard transaction types

Parameters

[in]

mapInputs

Map of previous transactions that have outputs we're spending

Returns

True if all inputs (scriptSigs) use only standard transaction forms

Definition at line 123 of file policy.cpp.

Referenced by AcceptToMemoryPoolWorker().

IsStandard()

bool IsStandard	(	const CScript &	scriptPubKey,
		txnouttype &	whichType
	)

Check transaction inputs to mitigate two potential denial-of-service attacks:

1. scriptSigs with extra data stuffed into them, not consumed by scriptPubKey (or P2SH script)
2. P2SH scripts with a crazy number of expensive CHECKSIG/CHECKMULTISIG operations

Check transaction inputs, and make sure any pay-to-script-hash transactions are evaluating IsStandard scripts

Why bother? To avoid denial-of-service attacks; an attacker can submit a standard HASH... OP_EQUAL transaction, which will get accepted into blocks. The redemption script can be anything; an attacker could use a very expensive-to-check-upon-redemption script like: DUP CHECKSIG DROP ... repeated 100 times... OP_1

Definition at line 37 of file policy.cpp.

Referenced by IsStandardTx().

IsStandardTx()

bool IsStandardTx	(	const CTransaction &	tx,
		std::string &	reason
	)

Check for standard transaction types

Returns

True if all outputs (scriptPubKeys) use only standard transaction forms

Definition at line 59 of file policy.cpp.

Referenced by AcceptToMemoryPoolWorker().