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2303 lines (2036 loc) · 77.9 KB
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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2012 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <boost/foreach.hpp>
#include <boost/tuple/tuple.hpp>
#include <boost/tuple/tuple_comparison.hpp>
using namespace std;
using namespace boost;
#include "script.h"
#include "keystore.h"
#include "bignum.h"
#include "key.h"
#include "main.h"
#include "sync.h"
#include "util.h"
bool CheckSig(vector<unsigned char> vchSig, const vector<unsigned char> &vchPubKey, const CScript &scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType, int flags);
static const valtype vchFalse(0);
static const valtype vchZero(0);
static const valtype vchTrue(1, 1);
static const CBigNum bnZero(0);
static const CBigNum bnOne(1);
static const CBigNum bnFalse(0);
static const CBigNum bnTrue(1);
static const size_t nDefaultMaxNumSize = 4;
CBigNum CastToBigNum(const valtype& vch, const size_t nMaxNumSize = nDefaultMaxNumSize)
{
if (vch.size() > nMaxNumSize)
throw runtime_error("CastToBigNum() : overflow");
// Get rid of extra leading zeros
return CBigNum(CBigNum(vch).getvch());
}
bool CastToBool(const valtype& vch)
{
for (unsigned int i = 0; i < vch.size(); i++)
{
if (vch[i] != 0)
{
// Can be negative zero
if (i == vch.size()-1 && vch[i] == 0x80)
return false;
return true;
}
}
return false;
}
//
// WARNING: This does not work as expected for signed integers; the sign-bit
// is left in place as the integer is zero-extended. The correct behavior
// would be to move the most significant bit of the last byte during the
// resize process. MakeSameSize() is currently only used by the disabled
// opcodes OP_AND, OP_OR, and OP_XOR.
//
void MakeSameSize(valtype& vch1, valtype& vch2)
{
// Lengthen the shorter one
if (vch1.size() < vch2.size())
// PATCH:
// +unsigned char msb = vch1[vch1.size()-1];
// +vch1[vch1.size()-1] &= 0x7f;
// vch1.resize(vch2.size(), 0);
// +vch1[vch1.size()-1] = msb;
vch1.resize(vch2.size(), 0);
if (vch2.size() < vch1.size())
// PATCH:
// +unsigned char msb = vch2[vch2.size()-1];
// +vch2[vch2.size()-1] &= 0x7f;
// vch2.resize(vch1.size(), 0);
// +vch2[vch2.size()-1] = msb;
vch2.resize(vch1.size(), 0);
}
//
// Script is a stack machine (like Forth) that evaluates a predicate
// returning a bool indicating valid or not. There are no loops.
//
#define stacktop(i) (stack.at(stack.size()+(i)))
#define altstacktop(i) (altstack.at(altstack.size()+(i)))
static inline void popstack(vector<valtype>& stack)
{
if (stack.empty())
throw runtime_error("popstack() : stack empty");
stack.pop_back();
}
const char* GetTxnOutputType(txnouttype t)
{
switch (t)
{
case TX_NONSTANDARD: return "nonstandard";
case TX_PUBKEY: return "pubkey";
case TX_PUBKEYHASH: return "pubkeyhash";
case TX_SCRIPTHASH: return "scripthash";
case TX_MULTISIG: return "multisig";
case TX_NULL_DATA: return "nulldata";
}
return NULL;
}
const char* GetOpName(opcodetype opcode)
{
switch (opcode)
{
// push value
case OP_0 : return "0";
case OP_PUSHDATA1 : return "OP_PUSHDATA1";
case OP_PUSHDATA2 : return "OP_PUSHDATA2";
case OP_PUSHDATA4 : return "OP_PUSHDATA4";
case OP_1NEGATE : return "-1";
case OP_RESERVED : return "OP_RESERVED";
case OP_1 : return "1";
case OP_2 : return "2";
case OP_3 : return "3";
case OP_4 : return "4";
case OP_5 : return "5";
case OP_6 : return "6";
case OP_7 : return "7";
case OP_8 : return "8";
case OP_9 : return "9";
case OP_10 : return "10";
case OP_11 : return "11";
case OP_12 : return "12";
case OP_13 : return "13";
case OP_14 : return "14";
case OP_15 : return "15";
case OP_16 : return "16";
// control
case OP_NOP : return "OP_NOP";
case OP_VER : return "OP_VER";
case OP_IF : return "OP_IF";
case OP_NOTIF : return "OP_NOTIF";
case OP_VERIF : return "OP_VERIF";
case OP_VERNOTIF : return "OP_VERNOTIF";
case OP_ELSE : return "OP_ELSE";
case OP_ENDIF : return "OP_ENDIF";
case OP_VERIFY : return "OP_VERIFY";
case OP_RETURN : return "OP_RETURN";
// stack ops
case OP_TOALTSTACK : return "OP_TOALTSTACK";
case OP_FROMALTSTACK : return "OP_FROMALTSTACK";
case OP_2DROP : return "OP_2DROP";
case OP_2DUP : return "OP_2DUP";
case OP_3DUP : return "OP_3DUP";
case OP_2OVER : return "OP_2OVER";
case OP_2ROT : return "OP_2ROT";
case OP_2SWAP : return "OP_2SWAP";
case OP_IFDUP : return "OP_IFDUP";
case OP_DEPTH : return "OP_DEPTH";
case OP_DROP : return "OP_DROP";
case OP_DUP : return "OP_DUP";
case OP_NIP : return "OP_NIP";
case OP_OVER : return "OP_OVER";
case OP_PICK : return "OP_PICK";
case OP_ROLL : return "OP_ROLL";
case OP_ROT : return "OP_ROT";
case OP_SWAP : return "OP_SWAP";
case OP_TUCK : return "OP_TUCK";
// splice ops
case OP_CAT : return "OP_CAT";
case OP_SUBSTR : return "OP_SUBSTR";
case OP_LEFT : return "OP_LEFT";
case OP_RIGHT : return "OP_RIGHT";
case OP_SIZE : return "OP_SIZE";
// bit logic
case OP_INVERT : return "OP_INVERT";
case OP_AND : return "OP_AND";
case OP_OR : return "OP_OR";
case OP_XOR : return "OP_XOR";
case OP_EQUAL : return "OP_EQUAL";
case OP_EQUALVERIFY : return "OP_EQUALVERIFY";
case OP_RESERVED1 : return "OP_RESERVED1";
case OP_RESERVED2 : return "OP_RESERVED2";
// numeric
case OP_1ADD : return "OP_1ADD";
case OP_1SUB : return "OP_1SUB";
case OP_2MUL : return "OP_2MUL";
case OP_2DIV : return "OP_2DIV";
case OP_NEGATE : return "OP_NEGATE";
case OP_ABS : return "OP_ABS";
case OP_NOT : return "OP_NOT";
case OP_0NOTEQUAL : return "OP_0NOTEQUAL";
case OP_ADD : return "OP_ADD";
case OP_SUB : return "OP_SUB";
case OP_MUL : return "OP_MUL";
case OP_DIV : return "OP_DIV";
case OP_MOD : return "OP_MOD";
case OP_LSHIFT : return "OP_LSHIFT";
case OP_RSHIFT : return "OP_RSHIFT";
case OP_BOOLAND : return "OP_BOOLAND";
case OP_BOOLOR : return "OP_BOOLOR";
case OP_NUMEQUAL : return "OP_NUMEQUAL";
case OP_NUMEQUALVERIFY : return "OP_NUMEQUALVERIFY";
case OP_NUMNOTEQUAL : return "OP_NUMNOTEQUAL";
case OP_LESSTHAN : return "OP_LESSTHAN";
case OP_GREATERTHAN : return "OP_GREATERTHAN";
case OP_LESSTHANOREQUAL : return "OP_LESSTHANOREQUAL";
case OP_GREATERTHANOREQUAL : return "OP_GREATERTHANOREQUAL";
case OP_MIN : return "OP_MIN";
case OP_MAX : return "OP_MAX";
case OP_WITHIN : return "OP_WITHIN";
// crypto
case OP_RIPEMD160 : return "OP_RIPEMD160";
case OP_SHA1 : return "OP_SHA1";
case OP_SHA256 : return "OP_SHA256";
case OP_HASH160 : return "OP_HASH160";
case OP_HASH256 : return "OP_HASH256";
case OP_CODESEPARATOR : return "OP_CODESEPARATOR";
case OP_CHECKSIG : return "OP_CHECKSIG";
case OP_CHECKSIGVERIFY : return "OP_CHECKSIGVERIFY";
case OP_CHECKMULTISIG : return "OP_CHECKMULTISIG";
case OP_CHECKMULTISIGVERIFY : return "OP_CHECKMULTISIGVERIFY";
// expanson
case OP_NOP1 : return "OP_NOP1";
case OP_CHECKLOCKTIMEVERIFY : return "OP_CHECKLOCKTIMEVERIFY";
case OP_NOP3 : return "OP_NOP3";
case OP_NOP4 : return "OP_NOP4";
case OP_NOP5 : return "OP_NOP5";
case OP_NOP6 : return "OP_NOP6";
case OP_NOP7 : return "OP_NOP7";
case OP_NOP8 : return "OP_NOP8";
case OP_NOP9 : return "OP_NOP9";
case OP_NOP10 : return "OP_NOP10";
case OP_INVALIDOPCODE : return "OP_INVALIDOPCODE";
// Note:
// The template matching params OP_SMALLDATA/etc are defined in opcodetype enum
// as kind of implementation hack, they are *NOT* real opcodes. If found in real
// Script, just let the default: case deal with them.
default:
return "OP_UNKNOWN";
}
}
bool IsCompressedOrUncompressedPubKey(const valtype &vchPubKey) {
if (vchPubKey.size() < 33)
return error("Non-canonical public key: too short");
if (vchPubKey[0] == 0x04) {
if (vchPubKey.size() != 65)
return error("Non-canonical public key: invalid length for uncompressed key");
} else if (vchPubKey[0] == 0x02 || vchPubKey[0] == 0x03) {
if (vchPubKey.size() != 33)
return error("Non-canonical public key: invalid length for compressed key");
} else {
return error("Non-canonical public key: neither compressed nor uncompressed");
}
return true;
}
bool IsDERSignature(const valtype &vchSig, bool haveHashType) {
// See https://bitcointalk.org/index.php?topic=8392.msg127623#msg127623
// A canonical signature exists of: <30> <total len> <02> <len R> <R> <02> <len S> <S> <hashtype>
// Where R and S are not negative (their first byte has its highest bit not set), and not
// excessively padded (do not start with a 0 byte, unless an otherwise negative number follows,
// in which case a single 0 byte is necessary and even required).
if (vchSig.size() < 9)
return error("Non-canonical signature: too short");
if (vchSig.size() > 73)
return error("Non-canonical signature: too long");
if (vchSig[0] != 0x30)
return error("Non-canonical signature: wrong type");
if (vchSig[1] != vchSig.size() - (haveHashType ? 3 : 2))
return error("Non-canonical signature: wrong length marker");
unsigned int nLenR = vchSig[3];
if (5 + nLenR >= vchSig.size())
return error("Non-canonical signature: S length misplaced");
unsigned int nLenS = vchSig[5+nLenR];
if ((unsigned long)(nLenR + nLenS + (haveHashType ? 7 : 6)) != vchSig.size())
return error("Non-canonical signature: R+S length mismatch");
const unsigned char *R = &vchSig[4];
if (R[-2] != 0x02)
return error("Non-canonical signature: R value type mismatch");
if (nLenR == 0)
return error("Non-canonical signature: R length is zero");
if (R[0] & 0x80)
return error("Non-canonical signature: R value negative");
if (nLenR > 1 && (R[0] == 0x00) && !(R[1] & 0x80))
return error("Non-canonical signature: R value excessively padded");
const unsigned char *S = &vchSig[6+nLenR];
if (S[-2] != 0x02)
return error("Non-canonical signature: S value type mismatch");
if (nLenS == 0)
return error("Non-canonical signature: S length is zero");
if (S[0] & 0x80)
return error("Non-canonical signature: S value negative");
if (nLenS > 1 && (S[0] == 0x00) && !(S[1] & 0x80))
return error("Non-canonical signature: S value excessively padded");
return true;
}
bool IsLowDERSignature(const valtype &vchSig, bool haveHashType) {
if (!IsDERSignature(vchSig, haveHashType)) {
return false;
}
unsigned int nLenR = vchSig[3];
unsigned int nLenS = vchSig[5+nLenR];
const unsigned char *S = &vchSig[6+nLenR];
// If the S value is above the order of the curve divided by two, its
// complement modulo the order could have been used instead, which is
// one byte shorter when encoded correctly.
if (!CKey::CheckSignatureElement(S, nLenS, true))
return error("Non-canonical signature: S value is unnecessarily high");
return true;
}
bool static IsDefinedHashtypeSignature(const valtype &vchSig) {
if (vchSig.size() == 0) {
return false;
}
unsigned char nHashType = vchSig[vchSig.size() - 1] & (~(SIGHASH_ANYONECANPAY));
if (nHashType < SIGHASH_ALL || nHashType > SIGHASH_SINGLE)
return error("Non-canonical signature: unknown hashtype byte");
return true;
}
bool static CheckSignatureEncoding(const valtype &vchSig, unsigned int flags) {
// Empty signature. Not strictly DER encoded, but allowed to provide a
// compact way to provide an invalid signature for use with CHECK(MULTI)SIG
if ((flags & SCRIPT_VERIFY_ALLOW_EMPTY_SIG) && vchSig.size() == 0) {
return true;
}
if (!IsLowDERSignature(vchSig)) {
return false;
} else if (!(flags & SCRIPT_VERIFY_FIX_HASHTYPE) && !IsDefinedHashtypeSignature(vchSig)) {
return false;
}
return true;
}
bool static CheckPubKeyEncoding(const valtype &vchSig) {
if (!IsCompressedOrUncompressedPubKey(vchSig)) {
return false;
}
return true;
}
static bool CheckLockTime(const CTransaction& txTo, unsigned int nIn, const CBigNum& nLockTime)
{
// There are two times of nLockTime: lock-by-blockheight
// and lock-by-blocktime, distinguished by whether
// nLockTime < LOCKTIME_THRESHOLD.
//
// We want to compare apples to apples, so fail the script
// unless the type of nLockTime being tested is the same as
// the nLockTime in the transaction.
if (!(
(txTo.nLockTime < LOCKTIME_THRESHOLD && nLockTime < LOCKTIME_THRESHOLD) ||
(txTo.nLockTime >= LOCKTIME_THRESHOLD && nLockTime >= LOCKTIME_THRESHOLD)
))
return false;
// Now that we know we're comparing apples-to-apples, the
// comparison is a simple numeric one.
if (nLockTime > (int64_t)txTo.nLockTime)
return false;
// Finally the nLockTime feature can be disabled and thus
// CHECKLOCKTIMEVERIFY bypassed if every txin has been
// finalized by setting nSequence to maxint. The
// transaction would be allowed into the blockchain, making
// the opcode ineffective.
//
// Testing if this vin is not final is sufficient to
// prevent this condition. Alternatively we could test all
// inputs, but testing just this input minimizes the data
// required to prove correct CHECKLOCKTIMEVERIFY execution.
if (txTo.vin[nIn].IsFinal())
return false;
return true;
}
bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, const CTransaction& txTo, unsigned int nIn, unsigned int flags, int nHashType)
{
CAutoBN_CTX pctx;
CScript::const_iterator pc = script.begin();
CScript::const_iterator pend = script.end();
CScript::const_iterator pbegincodehash = script.begin();
opcodetype opcode;
valtype vchPushValue;
vector<bool> vfExec;
vector<valtype> altstack;
if (script.size() > 10000)
return false;
int nOpCount = 0;
try
{
while (pc < pend)
{
bool fExec = !count(vfExec.begin(), vfExec.end(), false);
//
// Read instruction
//
if (!script.GetOp(pc, opcode, vchPushValue))
return false;
if (vchPushValue.size() > MAX_SCRIPT_ELEMENT_SIZE)
return false;
if (opcode > OP_16 && ++nOpCount > 201)
return false;
if (opcode == OP_CAT ||
opcode == OP_SUBSTR ||
opcode == OP_LEFT ||
opcode == OP_RIGHT ||
opcode == OP_INVERT ||
opcode == OP_AND ||
opcode == OP_OR ||
opcode == OP_XOR ||
opcode == OP_2MUL ||
opcode == OP_2DIV ||
opcode == OP_MUL ||
opcode == OP_DIV ||
opcode == OP_MOD ||
opcode == OP_LSHIFT ||
opcode == OP_RSHIFT)
return false;
if (fExec && 0 <= opcode && opcode <= OP_PUSHDATA4)
stack.push_back(vchPushValue);
else if (fExec || (OP_IF <= opcode && opcode <= OP_ENDIF))
switch (opcode)
{
//
// Push value
//
case OP_1NEGATE:
case OP_1:
case OP_2:
case OP_3:
case OP_4:
case OP_5:
case OP_6:
case OP_7:
case OP_8:
case OP_9:
case OP_10:
case OP_11:
case OP_12:
case OP_13:
case OP_14:
case OP_15:
case OP_16:
{
// ( -- value)
CBigNum bn((int)opcode - (int)(OP_1 - 1));
stack.push_back(bn.getvch());
}
break;
//
// Control
//
case OP_NOP:
break;
case OP_CHECKLOCKTIMEVERIFY:
{
if (!(flags & SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY)) {
// not enabled; treat as a NOP2
if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) {
return false;
}
break;
}
if (stack.size() < 1)
return false;
// Note that elsewhere numeric opcodes are limited to
// operands in the range -2**31+1 to 2**31-1, however it is
// legal for opcodes to produce results exceeding that
// range. This limitation is implemented by CScriptNum's
// default 4-byte limit.
//
// If we kept to that limit we'd have a year 2038 problem,
// even though the nLockTime field in transactions
// themselves is uint32 which only becomes meaningless
// after the year 2106.
//
// Thus as a special case we tell CScriptNum to accept up
// to 5-byte bignums, which are good until 2**32-1, the
// same limit as the nLockTime field itself.
const CBigNum nLockTime = CastToBigNum(stacktop(-1), 5);
// In the rare event that the argument may be < 0 due to
// some arithmetic being done first, you can always use
// 0 MAX CHECKLOCKTIMEVERIFY.
if (nLockTime < 0)
return false;
// Actually compare the specified lock time with the transaction.
if (!CheckLockTime(txTo, nIn, nLockTime))
return false;
break;
}
case OP_NOP1: case OP_NOP3: case OP_NOP4: case OP_NOP5:
case OP_NOP6: case OP_NOP7: case OP_NOP8: case OP_NOP9: case OP_NOP10:
{
if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS)
return false;
}
break;
case OP_IF:
case OP_NOTIF:
{
// <expression> if [statements] [else [statements]] endif
bool fValue = false;
if (fExec)
{
if (stack.size() < 1)
return false;
valtype& vch = stacktop(-1);
fValue = CastToBool(vch);
if (opcode == OP_NOTIF)
fValue = !fValue;
popstack(stack);
}
vfExec.push_back(fValue);
}
break;
case OP_ELSE:
{
if (vfExec.empty())
return false;
vfExec.back() = !vfExec.back();
}
break;
case OP_ENDIF:
{
if (vfExec.empty())
return false;
vfExec.pop_back();
}
break;
case OP_VERIFY:
{
// (true -- ) or
// (false -- false) and return
if (stack.size() < 1)
return false;
bool fValue = CastToBool(stacktop(-1));
if (fValue)
popstack(stack);
else
return false;
}
break;
case OP_RETURN:
{
return false;
}
break;
//
// Stack ops
//
case OP_TOALTSTACK:
{
if (stack.size() < 1)
return false;
altstack.push_back(stacktop(-1));
popstack(stack);
}
break;
case OP_FROMALTSTACK:
{
if (altstack.size() < 1)
return false;
stack.push_back(altstacktop(-1));
popstack(altstack);
}
break;
case OP_2DROP:
{
// (x1 x2 -- )
if (stack.size() < 2)
return false;
popstack(stack);
popstack(stack);
}
break;
case OP_2DUP:
{
// (x1 x2 -- x1 x2 x1 x2)
if (stack.size() < 2)
return false;
valtype vch1 = stacktop(-2);
valtype vch2 = stacktop(-1);
stack.push_back(vch1);
stack.push_back(vch2);
}
break;
case OP_3DUP:
{
// (x1 x2 x3 -- x1 x2 x3 x1 x2 x3)
if (stack.size() < 3)
return false;
valtype vch1 = stacktop(-3);
valtype vch2 = stacktop(-2);
valtype vch3 = stacktop(-1);
stack.push_back(vch1);
stack.push_back(vch2);
stack.push_back(vch3);
}
break;
case OP_2OVER:
{
// (x1 x2 x3 x4 -- x1 x2 x3 x4 x1 x2)
if (stack.size() < 4)
return false;
valtype vch1 = stacktop(-4);
valtype vch2 = stacktop(-3);
stack.push_back(vch1);
stack.push_back(vch2);
}
break;
case OP_2ROT:
{
// (x1 x2 x3 x4 x5 x6 -- x3 x4 x5 x6 x1 x2)
if (stack.size() < 6)
return false;
valtype vch1 = stacktop(-6);
valtype vch2 = stacktop(-5);
stack.erase(stack.end()-6, stack.end()-4);
stack.push_back(vch1);
stack.push_back(vch2);
}
break;
case OP_2SWAP:
{
// (x1 x2 x3 x4 -- x3 x4 x1 x2)
if (stack.size() < 4)
return false;
swap(stacktop(-4), stacktop(-2));
swap(stacktop(-3), stacktop(-1));
}
break;
case OP_IFDUP:
{
// (x - 0 | x x)
if (stack.size() < 1)
return false;
valtype vch = stacktop(-1);
if (CastToBool(vch))
stack.push_back(vch);
}
break;
case OP_DEPTH:
{
// -- stacksize
CBigNum bn(stack.size());
stack.push_back(bn.getvch());
}
break;
case OP_DROP:
{
// (x -- )
if (stack.size() < 1)
return false;
popstack(stack);
}
break;
case OP_DUP:
{
// (x -- x x)
if (stack.size() < 1)
return false;
valtype vch = stacktop(-1);
stack.push_back(vch);
}
break;
case OP_NIP:
{
// (x1 x2 -- x2)
if (stack.size() < 2)
return false;
stack.erase(stack.end() - 2);
}
break;
case OP_OVER:
{
// (x1 x2 -- x1 x2 x1)
if (stack.size() < 2)
return false;
valtype vch = stacktop(-2);
stack.push_back(vch);
}
break;
case OP_PICK:
case OP_ROLL:
{
// (xn ... x2 x1 x0 n - xn ... x2 x1 x0 xn)
// (xn ... x2 x1 x0 n - ... x2 x1 x0 xn)
if (stack.size() < 2)
return false;
int n = CastToBigNum(stacktop(-1)).getint();
popstack(stack);
if (n < 0 || n >= (int)stack.size())
return false;
valtype vch = stacktop(-n-1);
if (opcode == OP_ROLL)
stack.erase(stack.end()-n-1);
stack.push_back(vch);
}
break;
case OP_ROT:
{
// (x1 x2 x3 -- x2 x3 x1)
// x2 x1 x3 after first swap
// x2 x3 x1 after second swap
if (stack.size() < 3)
return false;
swap(stacktop(-3), stacktop(-2));
swap(stacktop(-2), stacktop(-1));
}
break;
case OP_SWAP:
{
// (x1 x2 -- x2 x1)
if (stack.size() < 2)
return false;
swap(stacktop(-2), stacktop(-1));
}
break;
case OP_TUCK:
{
// (x1 x2 -- x2 x1 x2)
if (stack.size() < 2)
return false;
valtype vch = stacktop(-1);
stack.insert(stack.end()-2, vch);
}
break;
//
// Splice ops
//
case OP_CAT:
{
// (x1 x2 -- out)
if (stack.size() < 2)
return false;
valtype& vch1 = stacktop(-2);
valtype& vch2 = stacktop(-1);
vch1.insert(vch1.end(), vch2.begin(), vch2.end());
popstack(stack);
if (stacktop(-1).size() > MAX_SCRIPT_ELEMENT_SIZE)
return false;
}
break;
case OP_SUBSTR:
{
// (in begin size -- out)
if (stack.size() < 3)
return false;
valtype& vch = stacktop(-3);
int nBegin = CastToBigNum(stacktop(-2)).getint();
int nEnd = nBegin + CastToBigNum(stacktop(-1)).getint();
if (nBegin < 0 || nEnd < nBegin)
return false;
if (nBegin > (int)vch.size())
nBegin = vch.size();
if (nEnd > (int)vch.size())
nEnd = vch.size();
vch.erase(vch.begin() + nEnd, vch.end());
vch.erase(vch.begin(), vch.begin() + nBegin);
popstack(stack);
popstack(stack);
}
break;
case OP_LEFT:
case OP_RIGHT:
{
// (in size -- out)
if (stack.size() < 2)
return false;
valtype& vch = stacktop(-2);
int nSize = CastToBigNum(stacktop(-1)).getint();
if (nSize < 0)
return false;
if (nSize > (int)vch.size())
nSize = vch.size();
if (opcode == OP_LEFT)
vch.erase(vch.begin() + nSize, vch.end());
else
vch.erase(vch.begin(), vch.end() - nSize);
popstack(stack);
}
break;
case OP_SIZE:
{
// (in -- in size)
if (stack.size() < 1)
return false;
CBigNum bn(stacktop(-1).size());
stack.push_back(bn.getvch());
}
break;
//
// Bitwise logic
//
case OP_INVERT:
{
// (in - out)
if (stack.size() < 1)
return false;
valtype& vch = stacktop(-1);
for (unsigned int i = 0; i < vch.size(); i++)
vch[i] = ~vch[i];
}
break;
//
// WARNING: These disabled opcodes exhibit unexpected behavior
// when used on signed integers due to a bug in MakeSameSize()
// [see definition of MakeSameSize() above].
//
case OP_AND:
case OP_OR:
case OP_XOR:
{
// (x1 x2 - out)
if (stack.size() < 2)
return false;
valtype& vch1 = stacktop(-2);
valtype& vch2 = stacktop(-1);
MakeSameSize(vch1, vch2); // <-- NOT SAFE FOR SIGNED VALUES
if (opcode == OP_AND)
{
for (unsigned int i = 0; i < vch1.size(); i++)
vch1[i] &= vch2[i];
}
else if (opcode == OP_OR)
{
for (unsigned int i = 0; i < vch1.size(); i++)
vch1[i] |= vch2[i];
}
else if (opcode == OP_XOR)
{
for (unsigned int i = 0; i < vch1.size(); i++)
vch1[i] ^= vch2[i];
}
popstack(stack);
}
break;
case OP_EQUAL:
case OP_EQUALVERIFY:
//case OP_NOTEQUAL: // use OP_NUMNOTEQUAL
{
// (x1 x2 - bool)
if (stack.size() < 2)
return false;
valtype& vch1 = stacktop(-2);
valtype& vch2 = stacktop(-1);
bool fEqual = (vch1 == vch2);
// OP_NOTEQUAL is disabled because it would be too easy to say
// something like n != 1 and have some wiseguy pass in 1 with extra
// zero bytes after it (numerically, 0x01 == 0x0001 == 0x000001)
//if (opcode == OP_NOTEQUAL)
// fEqual = !fEqual;
popstack(stack);
popstack(stack);
stack.push_back(fEqual ? vchTrue : vchFalse);
if (opcode == OP_EQUALVERIFY)
{
if (fEqual)
popstack(stack);
else
return false;
}
}
break;
//
// Numeric
//
case OP_1ADD:
case OP_1SUB:
case OP_2MUL:
case OP_2DIV:
case OP_NEGATE:
case OP_ABS:
case OP_NOT:
case OP_0NOTEQUAL:
{
// (in -- out)
if (stack.size() < 1)
return false;
CBigNum bn = CastToBigNum(stacktop(-1));
switch (opcode)
{
case OP_1ADD: bn += bnOne; break;
case OP_1SUB: bn -= bnOne; break;
case OP_2MUL: bn <<= 1; break;
case OP_2DIV: bn >>= 1; break;
case OP_NEGATE: bn = -bn; break;
case OP_ABS: if (bn < bnZero) bn = -bn; break;
case OP_NOT: bn = (bn == bnZero); break;
case OP_0NOTEQUAL: bn = (bn != bnZero); break;
default: assert(!"invalid opcode"); break;
}
popstack(stack);
stack.push_back(bn.getvch());
}
break;
case OP_ADD:
case OP_SUB:
case OP_MUL:
case OP_DIV:
case OP_MOD:
case OP_LSHIFT:
case OP_RSHIFT:
case OP_BOOLAND:
case OP_BOOLOR:
case OP_NUMEQUAL:
case OP_NUMEQUALVERIFY:
case OP_NUMNOTEQUAL:
case OP_LESSTHAN:
case OP_GREATERTHAN:
case OP_LESSTHANOREQUAL:
case OP_GREATERTHANOREQUAL:
case OP_MIN:
case OP_MAX:
{
// (x1 x2 -- out)
if (stack.size() < 2)
return false;
CBigNum bn1 = CastToBigNum(stacktop(-2));
CBigNum bn2 = CastToBigNum(stacktop(-1));
CBigNum bn;
switch (opcode)
{
case OP_ADD:
bn = bn1 + bn2;
break;
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