lbrycrd/src/script.cpp

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// Copyright (c) 2009-2010 Satoshi Nakamoto
2012-02-07 17:28:30 +01:00
// Copyright (c) 2009-2012 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file license.txt or http://www.opensource.org/licenses/mit-license.php.
2012-04-15 22:10:54 +02:00
#include <boost/foreach.hpp>
using namespace std;
using namespace boost;
2012-04-15 22:10:54 +02:00
#include "script.h"
#include "keystore.h"
#include "bignum.h"
#include "key.h"
#include "main.h"
bool CheckSig(vector<unsigned char> vchSig, vector<unsigned char> vchPubKey, CScript scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType);
typedef vector<unsigned char> valtype;
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 nMaxNumSize = 4;
CBigNum CastToBigNum(const valtype& vch)
{
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;
}
void MakeSameSize(valtype& vch1, valtype& vch2)
{
// Lengthen the shorter one
if (vch1.size() < vch2.size())
vch1.resize(vch2.size(), 0);
if (vch2.size() < vch1.size())
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";
}
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_NOP2 : return "OP_NOP2";
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";
// template matching params
case OP_PUBKEYHASH : return "OP_PUBKEYHASH";
case OP_PUBKEY : return "OP_PUBKEY";
case OP_INVALIDOPCODE : return "OP_INVALIDOPCODE";
default:
return "OP_UNKNOWN";
}
}
bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, const CTransaction& txTo, unsigned int nIn, 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() > 520)
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:
case OP_NOP1: case OP_NOP2: case OP_NOP3: case OP_NOP4: case OP_NOP5:
case OP_NOP6: case OP_NOP7: case OP_NOP8: case OP_NOP9: case OP_NOP10:
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() > 520)
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;
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);
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;
case OP_SUB:
bn = bn1 - bn2;
break;
case OP_MUL:
if (!BN_mul(&bn, &bn1, &bn2, pctx))
return false;
break;
case OP_DIV:
if (!BN_div(&bn, NULL, &bn1, &bn2, pctx))
return false;
break;
case OP_MOD:
if (!BN_mod(&bn, &bn1, &bn2, pctx))
return false;
break;
case OP_LSHIFT:
if (bn2 < bnZero || bn2 > CBigNum(2048))
return false;
bn = bn1 << bn2.getulong();
break;
case OP_RSHIFT:
if (bn2 < bnZero || bn2 > CBigNum(2048))
return false;
bn = bn1 >> bn2.getulong();
break;
case OP_BOOLAND: bn = (bn1 != bnZero && bn2 != bnZero); break;
case OP_BOOLOR: bn = (bn1 != bnZero || bn2 != bnZero); break;
case OP_NUMEQUAL: bn = (bn1 == bn2); break;
case OP_NUMEQUALVERIFY: bn = (bn1 == bn2); break;
case OP_NUMNOTEQUAL: bn = (bn1 != bn2); break;
case OP_LESSTHAN: bn = (bn1 < bn2); break;
case OP_GREATERTHAN: bn = (bn1 > bn2); break;
case OP_LESSTHANOREQUAL: bn = (bn1 <= bn2); break;
case OP_GREATERTHANOREQUAL: bn = (bn1 >= bn2); break;
case OP_MIN: bn = (bn1 < bn2 ? bn1 : bn2); break;
case OP_MAX: bn = (bn1 > bn2 ? bn1 : bn2); break;
default: assert(!"invalid opcode"); break;
}
popstack(stack);
popstack(stack);
stack.push_back(bn.getvch());
if (opcode == OP_NUMEQUALVERIFY)
{
if (CastToBool(stacktop(-1)))
popstack(stack);
else
return false;
}
}
break;
case OP_WITHIN:
{
// (x min max -- out)
if (stack.size() < 3)
return false;
CBigNum bn1 = CastToBigNum(stacktop(-3));
CBigNum bn2 = CastToBigNum(stacktop(-2));
CBigNum bn3 = CastToBigNum(stacktop(-1));
bool fValue = (bn2 <= bn1 && bn1 < bn3);
popstack(stack);
popstack(stack);
popstack(stack);
stack.push_back(fValue ? vchTrue : vchFalse);
}
break;
//
// Crypto
//
case OP_RIPEMD160:
case OP_SHA1:
case OP_SHA256:
case OP_HASH160:
case OP_HASH256:
{
// (in -- hash)
if (stack.size() < 1)
return false;
valtype& vch = stacktop(-1);
valtype vchHash((opcode == OP_RIPEMD160 || opcode == OP_SHA1 || opcode == OP_HASH160) ? 20 : 32);
if (opcode == OP_RIPEMD160)
RIPEMD160(&vch[0], vch.size(), &vchHash[0]);
else if (opcode == OP_SHA1)
SHA1(&vch[0], vch.size(), &vchHash[0]);
else if (opcode == OP_SHA256)
SHA256(&vch[0], vch.size(), &vchHash[0]);
else if (opcode == OP_HASH160)
{
uint160 hash160 = Hash160(vch);
memcpy(&vchHash[0], &hash160, sizeof(hash160));
}
else if (opcode == OP_HASH256)
{
uint256 hash = Hash(vch.begin(), vch.end());
memcpy(&vchHash[0], &hash, sizeof(hash));
}
popstack(stack);
stack.push_back(vchHash);
}
break;
case OP_CODESEPARATOR:
{
// Hash starts after the code separator
pbegincodehash = pc;
}
break;
case OP_CHECKSIG:
case OP_CHECKSIGVERIFY:
{
// (sig pubkey -- bool)
if (stack.size() < 2)
return false;
valtype& vchSig = stacktop(-2);
valtype& vchPubKey = stacktop(-1);
////// debug print
//PrintHex(vchSig.begin(), vchSig.end(), "sig: %s\n");
//PrintHex(vchPubKey.begin(), vchPubKey.end(), "pubkey: %s\n");
// Subset of script starting at the most recent codeseparator
CScript scriptCode(pbegincodehash, pend);
// Drop the signature, since there's no way for a signature to sign itself
scriptCode.FindAndDelete(CScript(vchSig));
bool fSuccess = CheckSig(vchSig, vchPubKey, scriptCode, txTo, nIn, nHashType);
popstack(stack);
popstack(stack);
stack.push_back(fSuccess ? vchTrue : vchFalse);
if (opcode == OP_CHECKSIGVERIFY)
{
if (fSuccess)
popstack(stack);
else
return false;
}
}
break;
case OP_CHECKMULTISIG:
case OP_CHECKMULTISIGVERIFY:
{
// ([sig ...] num_of_signatures [pubkey ...] num_of_pubkeys -- bool)
int i = 1;
if ((int)stack.size() < i)
return false;
int nKeysCount = CastToBigNum(stacktop(-i)).getint();
if (nKeysCount < 0 || nKeysCount > 20)
return false;
nOpCount += nKeysCount;
if (nOpCount > 201)
return false;
int ikey = ++i;
i += nKeysCount;
if ((int)stack.size() < i)
return false;
int nSigsCount = CastToBigNum(stacktop(-i)).getint();
if (nSigsCount < 0 || nSigsCount > nKeysCount)
return false;
int isig = ++i;
i += nSigsCount;
if ((int)stack.size() < i)
return false;
// Subset of script starting at the most recent codeseparator
CScript scriptCode(pbegincodehash, pend);
// Drop the signatures, since there's no way for a signature to sign itself
for (int k = 0; k < nSigsCount; k++)
{
valtype& vchSig = stacktop(-isig-k);
scriptCode.FindAndDelete(CScript(vchSig));
}
bool fSuccess = true;
while (fSuccess && nSigsCount > 0)
{
valtype& vchSig = stacktop(-isig);
valtype& vchPubKey = stacktop(-ikey);
// Check signature
if (CheckSig(vchSig, vchPubKey, scriptCode, txTo, nIn, nHashType))
{
isig++;
nSigsCount--;
}
ikey++;
nKeysCount--;
// If there are more signatures left than keys left,
// then too many signatures have failed
if (nSigsCount > nKeysCount)
fSuccess = false;
}
while (i-- > 0)
popstack(stack);
stack.push_back(fSuccess ? vchTrue : vchFalse);
if (opcode == OP_CHECKMULTISIGVERIFY)
{
if (fSuccess)
popstack(stack);
else
return false;
}
}
break;
default:
return false;
}
// Size limits
if (stack.size() + altstack.size() > 1000)
return false;
}
}
catch (...)
{
return false;
}
if (!vfExec.empty())
return false;
return true;
}
uint256 SignatureHash(CScript scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType)
{
if (nIn >= txTo.vin.size())
{
printf("ERROR: SignatureHash() : nIn=%d out of range\n", nIn);
return 1;
}
CTransaction txTmp(txTo);
// In case concatenating two scripts ends up with two codeseparators,
// or an extra one at the end, this prevents all those possible incompatibilities.
scriptCode.FindAndDelete(CScript(OP_CODESEPARATOR));
// Blank out other inputs' signatures
for (unsigned int i = 0; i < txTmp.vin.size(); i++)
txTmp.vin[i].scriptSig = CScript();
txTmp.vin[nIn].scriptSig = scriptCode;
// Blank out some of the outputs
if ((nHashType & 0x1f) == SIGHASH_NONE)
{
// Wildcard payee
txTmp.vout.clear();
// Let the others update at will
for (unsigned int i = 0; i < txTmp.vin.size(); i++)
if (i != nIn)
txTmp.vin[i].nSequence = 0;
}
else if ((nHashType & 0x1f) == SIGHASH_SINGLE)
{
// Only lockin the txout payee at same index as txin
unsigned int nOut = nIn;
if (nOut >= txTmp.vout.size())
{
printf("ERROR: SignatureHash() : nOut=%d out of range\n", nOut);
return 1;
}
txTmp.vout.resize(nOut+1);
for (unsigned int i = 0; i < nOut; i++)
txTmp.vout[i].SetNull();
// Let the others update at will
for (unsigned int i = 0; i < txTmp.vin.size(); i++)
if (i != nIn)
txTmp.vin[i].nSequence = 0;
}
// Blank out other inputs completely, not recommended for open transactions
if (nHashType & SIGHASH_ANYONECANPAY)
{
txTmp.vin[0] = txTmp.vin[nIn];
txTmp.vin.resize(1);
}
// Serialize and hash
CDataStream ss(SER_GETHASH, 0);
ss.reserve(10000);
ss << txTmp << nHashType;
return Hash(ss.begin(), ss.end());
}
bool CheckSig(vector<unsigned char> vchSig, vector<unsigned char> vchPubKey, CScript scriptCode,
const CTransaction& txTo, unsigned int nIn, int nHashType)
{
CKey key;
if (!key.SetPubKey(vchPubKey))
return false;
// Hash type is one byte tacked on to the end of the signature
if (vchSig.empty())
return false;
if (nHashType == 0)
nHashType = vchSig.back();
else if (nHashType != vchSig.back())
return false;
vchSig.pop_back();
return key.Verify(SignatureHash(scriptCode, txTo, nIn, nHashType), vchSig);
}
//
// Return public keys or hashes from scriptPubKey, for 'standard' transaction types.
//
bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, vector<vector<unsigned char> >& vSolutionsRet)
{
// Templates
static map<txnouttype, CScript> mTemplates;
if (mTemplates.empty())
{
// Standard tx, sender provides pubkey, receiver adds signature
mTemplates.insert(make_pair(TX_PUBKEY, CScript() << OP_PUBKEY << OP_CHECKSIG));
// Bitcoin address tx, sender provides hash of pubkey, receiver provides signature and pubkey
mTemplates.insert(make_pair(TX_PUBKEYHASH, CScript() << OP_DUP << OP_HASH160 << OP_PUBKEYHASH << OP_EQUALVERIFY << OP_CHECKSIG));
// Sender provides N pubkeys, receivers provides M signatures
mTemplates.insert(make_pair(TX_MULTISIG, CScript() << OP_SMALLINTEGER << OP_PUBKEYS << OP_SMALLINTEGER << OP_CHECKMULTISIG));
}
// Shortcut for pay-to-script-hash, which are more constrained than the other types:
// it is always OP_HASH160 20 [20 byte hash] OP_EQUAL
if (scriptPubKey.IsPayToScriptHash())
{
typeRet = TX_SCRIPTHASH;
vector<unsigned char> hashBytes(scriptPubKey.begin()+2, scriptPubKey.begin()+22);
vSolutionsRet.push_back(hashBytes);
return true;
}
// Scan templates
const CScript& script1 = scriptPubKey;
BOOST_FOREACH(const PAIRTYPE(txnouttype, CScript)& tplate, mTemplates)
{
const CScript& script2 = tplate.second;
vSolutionsRet.clear();
opcodetype opcode1, opcode2;
vector<unsigned char> vch1, vch2;
// Compare
CScript::const_iterator pc1 = script1.begin();
CScript::const_iterator pc2 = script2.begin();
loop
{
if (pc1 == script1.end() && pc2 == script2.end())
{
// Found a match
typeRet = tplate.first;
if (typeRet == TX_MULTISIG)
{
// Additional checks for TX_MULTISIG:
unsigned char m = vSolutionsRet.front()[0];
unsigned char n = vSolutionsRet.back()[0];
if (m < 1 || n < 1 || m > n || vSolutionsRet.size()-2 != n)
return false;
}
return true;
}
if (!script1.GetOp(pc1, opcode1, vch1))
break;
if (!script2.GetOp(pc2, opcode2, vch2))
break;
// Template matching opcodes:
if (opcode2 == OP_PUBKEYS)
{
while (vch1.size() >= 33 && vch1.size() <= 120)
{
vSolutionsRet.push_back(vch1);
if (!script1.GetOp(pc1, opcode1, vch1))
break;
}
if (!script2.GetOp(pc2, opcode2, vch2))
break;
// Normal situation is to fall through
// to other if/else statments
}
if (opcode2 == OP_PUBKEY)
{
if (vch1.size() < 33 || vch1.size() > 120)
break;
vSolutionsRet.push_back(vch1);
}
else if (opcode2 == OP_PUBKEYHASH)
{
if (vch1.size() != sizeof(uint160))
break;
vSolutionsRet.push_back(vch1);
}
else if (opcode2 == OP_SMALLINTEGER)
{ // Single-byte small integer pushed onto vSolutions
if (opcode1 == OP_0 ||
(opcode1 >= OP_1 && opcode1 <= OP_16))
{
char n = (char)CScript::DecodeOP_N(opcode1);
vSolutionsRet.push_back(valtype(1, n));
}
else
break;
}
else if (opcode1 != opcode2 || vch1 != vch2)
{
// Others must match exactly
break;
}
}
}
vSolutionsRet.clear();
typeRet = TX_NONSTANDARD;
return false;
}
bool Sign1(const CBitcoinAddress& address, const CKeyStore& keystore, uint256 hash, int nHashType, CScript& scriptSigRet)
{
CKey key;
if (!keystore.GetKey(address, key))
return false;
vector<unsigned char> vchSig;
if (!key.Sign(hash, vchSig))
return false;
vchSig.push_back((unsigned char)nHashType);
scriptSigRet << vchSig;
return true;
}
bool SignN(const vector<valtype>& multisigdata, const CKeyStore& keystore, uint256 hash, int nHashType, CScript& scriptSigRet)
{
int nSigned = 0;
int nRequired = multisigdata.front()[0];
for (vector<valtype>::const_iterator it = multisigdata.begin()+1; it != multisigdata.begin()+multisigdata.size()-1; it++)
{
const valtype& pubkey = *it;
CBitcoinAddress address;
address.SetPubKey(pubkey);
if (Sign1(address, keystore, hash, nHashType, scriptSigRet))
{
++nSigned;
if (nSigned == nRequired) break;
}
}
return nSigned==nRequired;
}
//
// Sign scriptPubKey with private keys stored in keystore, given transaction hash and hash type.
// Signatures are returned in scriptSigRet (or returns false if scriptPubKey can't be signed),
// unless whichTypeRet is TX_SCRIPTHASH, in which case scriptSigRet is the redemption script.
// Returns false if scriptPubKey could not be completely satisified.
//
bool Solver(const CKeyStore& keystore, const CScript& scriptPubKey, uint256 hash, int nHashType,
CScript& scriptSigRet, txnouttype& whichTypeRet)
{
scriptSigRet.clear();
vector<valtype> vSolutions;
if (!Solver(scriptPubKey, whichTypeRet, vSolutions))
return false;
CBitcoinAddress address;
switch (whichTypeRet)
{
case TX_NONSTANDARD:
return false;
case TX_PUBKEY:
address.SetPubKey(vSolutions[0]);
return Sign1(address, keystore, hash, nHashType, scriptSigRet);
case TX_PUBKEYHASH:
address.SetHash160(uint160(vSolutions[0]));
if (!Sign1(address, keystore, hash, nHashType, scriptSigRet))
return false;
else
{
valtype vch;
keystore.GetPubKey(address, vch);
scriptSigRet << vch;
}
return true;
case TX_SCRIPTHASH:
return keystore.GetCScript(uint160(vSolutions[0]), scriptSigRet);
case TX_MULTISIG:
scriptSigRet << OP_0; // workaround CHECKMULTISIG bug
return (SignN(vSolutions, keystore, hash, nHashType, scriptSigRet));
}
return false;
}
int ScriptSigArgsExpected(txnouttype t, const std::vector<std::vector<unsigned char> >& vSolutions)
{
switch (t)
{
case TX_NONSTANDARD:
return -1;
case TX_PUBKEY:
return 1;
case TX_PUBKEYHASH:
return 2;
case TX_MULTISIG:
if (vSolutions.size() < 1 || vSolutions[0].size() < 1)
return -1;
return vSolutions[0][0] + 1;
case TX_SCRIPTHASH:
return 1; // doesn't include args needed by the script
}
return -1;
}
bool IsStandard(const CScript& scriptPubKey)
{
vector<valtype> vSolutions;
txnouttype whichType;
if (!Solver(scriptPubKey, whichType, vSolutions))
return false;
if (whichType == TX_MULTISIG)
{
unsigned char m = vSolutions.front()[0];
unsigned char n = vSolutions.back()[0];
// Support up to x-of-3 multisig txns as standard
if (n < 1 || n > 3)
return false;
if (m < 1 || m > n)
return false;
}
return whichType != TX_NONSTANDARD;
}
unsigned int HaveKeys(const vector<valtype>& pubkeys, const CKeyStore& keystore)
{
unsigned int nResult = 0;
BOOST_FOREACH(const valtype& pubkey, pubkeys)
{
CBitcoinAddress address;
address.SetPubKey(pubkey);
if (keystore.HaveKey(address))
++nResult;
}
return nResult;
}
bool IsMine(const CKeyStore &keystore, const CScript& scriptPubKey)
{
vector<valtype> vSolutions;
txnouttype whichType;
if (!Solver(scriptPubKey, whichType, vSolutions))
Add wallet privkey encryption. This commit adds support for ckeys, or enCrypted private keys, to the wallet. All keys are stored in memory in their encrypted form and thus the passphrase is required from the user to spend coins, or to create new addresses. Keys are encrypted with AES-256-CBC using OpenSSL's EVP library. The key is calculated via EVP_BytesToKey using SHA512 with (by default) 25000 rounds and a random salt. By default, the user's wallet remains unencrypted until they call the RPC command encryptwallet <passphrase> or, from the GUI menu, Options-> Encrypt Wallet. When the user is attempting to call RPC functions which require the password to unlock the wallet, an error will be returned unless they call walletpassphrase <passphrase> <time to keep key in memory> first. A keypoolrefill command has been added which tops up the users keypool (requiring the passphrase via walletpassphrase first). keypoolsize has been added to the output of getinfo to show the user the number of keys left before they need to specify their passphrase (and call keypoolrefill). Note that walletpassphrase will automatically fill keypool in a separate thread which it spawns when the passphrase is set. This could cause some delays in other threads waiting for locks on the wallet passphrase, including one which could cause the passphrase to be stored longer than expected, however it will not allow the passphrase to be used longer than expected as ThreadCleanWalletPassphrase will attempt to get a lock on the key as soon as the specified lock time has arrived. When the keypool runs out (and wallet is locked) GetOrReuseKeyFromPool returns vchDefaultKey, meaning miners may start to generate many blocks to vchDefaultKey instead of a new key each time. A walletpassphrasechange <oldpassphrase> <newpassphrase> has been added to allow the user to change their password via RPC. Whenever keying material (unencrypted private keys, the user's passphrase, the wallet's AES key) is stored unencrypted in memory, any reasonable attempt is made to mlock/VirtualLock that memory before storing the keying material. This is not true in several (commented) cases where mlock/VirtualLocking the memory is not possible. Although encryption of private keys in memory can be very useful on desktop systems (as some small amount of protection against stupid viruses), on an RPC server, the password is entered fairly insecurely. Thus, the only main advantage encryption has for RPC servers is for RPC servers that do not spend coins, except in rare cases, eg. a webserver of a merchant which only receives payment except for cases of manual intervention. Thanks to jgarzik for the original patch and sipa, gmaxwell and many others for all their input. Conflicts: src/wallet.cpp
2011-07-08 15:47:35 +02:00
return false;
CBitcoinAddress address;
switch (whichType)
Add wallet privkey encryption. This commit adds support for ckeys, or enCrypted private keys, to the wallet. All keys are stored in memory in their encrypted form and thus the passphrase is required from the user to spend coins, or to create new addresses. Keys are encrypted with AES-256-CBC using OpenSSL's EVP library. The key is calculated via EVP_BytesToKey using SHA512 with (by default) 25000 rounds and a random salt. By default, the user's wallet remains unencrypted until they call the RPC command encryptwallet <passphrase> or, from the GUI menu, Options-> Encrypt Wallet. When the user is attempting to call RPC functions which require the password to unlock the wallet, an error will be returned unless they call walletpassphrase <passphrase> <time to keep key in memory> first. A keypoolrefill command has been added which tops up the users keypool (requiring the passphrase via walletpassphrase first). keypoolsize has been added to the output of getinfo to show the user the number of keys left before they need to specify their passphrase (and call keypoolrefill). Note that walletpassphrase will automatically fill keypool in a separate thread which it spawns when the passphrase is set. This could cause some delays in other threads waiting for locks on the wallet passphrase, including one which could cause the passphrase to be stored longer than expected, however it will not allow the passphrase to be used longer than expected as ThreadCleanWalletPassphrase will attempt to get a lock on the key as soon as the specified lock time has arrived. When the keypool runs out (and wallet is locked) GetOrReuseKeyFromPool returns vchDefaultKey, meaning miners may start to generate many blocks to vchDefaultKey instead of a new key each time. A walletpassphrasechange <oldpassphrase> <newpassphrase> has been added to allow the user to change their password via RPC. Whenever keying material (unencrypted private keys, the user's passphrase, the wallet's AES key) is stored unencrypted in memory, any reasonable attempt is made to mlock/VirtualLock that memory before storing the keying material. This is not true in several (commented) cases where mlock/VirtualLocking the memory is not possible. Although encryption of private keys in memory can be very useful on desktop systems (as some small amount of protection against stupid viruses), on an RPC server, the password is entered fairly insecurely. Thus, the only main advantage encryption has for RPC servers is for RPC servers that do not spend coins, except in rare cases, eg. a webserver of a merchant which only receives payment except for cases of manual intervention. Thanks to jgarzik for the original patch and sipa, gmaxwell and many others for all their input. Conflicts: src/wallet.cpp
2011-07-08 15:47:35 +02:00
{
case TX_NONSTANDARD:
return false;
case TX_PUBKEY:
address.SetPubKey(vSolutions[0]);
return keystore.HaveKey(address);
case TX_PUBKEYHASH:
address.SetHash160(uint160(vSolutions[0]));
return keystore.HaveKey(address);
case TX_SCRIPTHASH:
{
CScript subscript;
if (!keystore.GetCScript(uint160(vSolutions[0]), subscript))
return false;
return IsMine(keystore, subscript);
Add wallet privkey encryption. This commit adds support for ckeys, or enCrypted private keys, to the wallet. All keys are stored in memory in their encrypted form and thus the passphrase is required from the user to spend coins, or to create new addresses. Keys are encrypted with AES-256-CBC using OpenSSL's EVP library. The key is calculated via EVP_BytesToKey using SHA512 with (by default) 25000 rounds and a random salt. By default, the user's wallet remains unencrypted until they call the RPC command encryptwallet <passphrase> or, from the GUI menu, Options-> Encrypt Wallet. When the user is attempting to call RPC functions which require the password to unlock the wallet, an error will be returned unless they call walletpassphrase <passphrase> <time to keep key in memory> first. A keypoolrefill command has been added which tops up the users keypool (requiring the passphrase via walletpassphrase first). keypoolsize has been added to the output of getinfo to show the user the number of keys left before they need to specify their passphrase (and call keypoolrefill). Note that walletpassphrase will automatically fill keypool in a separate thread which it spawns when the passphrase is set. This could cause some delays in other threads waiting for locks on the wallet passphrase, including one which could cause the passphrase to be stored longer than expected, however it will not allow the passphrase to be used longer than expected as ThreadCleanWalletPassphrase will attempt to get a lock on the key as soon as the specified lock time has arrived. When the keypool runs out (and wallet is locked) GetOrReuseKeyFromPool returns vchDefaultKey, meaning miners may start to generate many blocks to vchDefaultKey instead of a new key each time. A walletpassphrasechange <oldpassphrase> <newpassphrase> has been added to allow the user to change their password via RPC. Whenever keying material (unencrypted private keys, the user's passphrase, the wallet's AES key) is stored unencrypted in memory, any reasonable attempt is made to mlock/VirtualLock that memory before storing the keying material. This is not true in several (commented) cases where mlock/VirtualLocking the memory is not possible. Although encryption of private keys in memory can be very useful on desktop systems (as some small amount of protection against stupid viruses), on an RPC server, the password is entered fairly insecurely. Thus, the only main advantage encryption has for RPC servers is for RPC servers that do not spend coins, except in rare cases, eg. a webserver of a merchant which only receives payment except for cases of manual intervention. Thanks to jgarzik for the original patch and sipa, gmaxwell and many others for all their input. Conflicts: src/wallet.cpp
2011-07-08 15:47:35 +02:00
}
case TX_MULTISIG:
{
// Only consider transactions "mine" if we own ALL the
// keys involved. multi-signature transactions that are
// partially owned (somebody else has a key that can spend
// them) enable spend-out-from-under-you attacks, especially
// in shared-wallet situations.
vector<valtype> keys(vSolutions.begin()+1, vSolutions.begin()+vSolutions.size()-1);
return HaveKeys(keys, keystore) == keys.size();
}
}
return false;
}
bool ExtractAddress(const CScript& scriptPubKey, CBitcoinAddress& addressRet)
{
vector<valtype> vSolutions;
txnouttype whichType;
if (!Solver(scriptPubKey, whichType, vSolutions))
return false;
if (whichType == TX_PUBKEY)
{
addressRet.SetPubKey(vSolutions[0]);
return true;
}
else if (whichType == TX_PUBKEYHASH)
{
addressRet.SetHash160(uint160(vSolutions[0]));
return true;
}
else if (whichType == TX_SCRIPTHASH)
{
addressRet.SetScriptHash160(uint160(vSolutions[0]));
return true;
}
// Multisig txns have more than one address...
return false;
}
bool ExtractAddresses(const CScript& scriptPubKey, txnouttype& typeRet, vector<CBitcoinAddress>& addressRet, int& nRequiredRet)
{
addressRet.clear();
typeRet = TX_NONSTANDARD;
vector<valtype> vSolutions;
if (!Solver(scriptPubKey, typeRet, vSolutions))
return false;
if (typeRet == TX_MULTISIG)
{
nRequiredRet = vSolutions.front()[0];
for (unsigned int i = 1; i < vSolutions.size()-1; i++)
{
CBitcoinAddress address;
address.SetPubKey(vSolutions[i]);
addressRet.push_back(address);
}
}
else
{
nRequiredRet = 1;
CBitcoinAddress address;
if (typeRet == TX_PUBKEYHASH)
address.SetHash160(uint160(vSolutions.front()));
else if (typeRet == TX_SCRIPTHASH)
address.SetScriptHash160(uint160(vSolutions.front()));
else if (typeRet == TX_PUBKEY)
address.SetPubKey(vSolutions.front());
addressRet.push_back(address);
}
return true;
}
bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, const CTransaction& txTo, unsigned int nIn,
bool fValidatePayToScriptHash, int nHashType)
{
vector<vector<unsigned char> > stack, stackCopy;
if (!EvalScript(stack, scriptSig, txTo, nIn, nHashType))
return false;
if (fValidatePayToScriptHash)
stackCopy = stack;
if (!EvalScript(stack, scriptPubKey, txTo, nIn, nHashType))
return false;
if (stack.empty())
return false;
if (CastToBool(stack.back()) == false)
return false;
// Additional validation for spend-to-script-hash transactions:
if (fValidatePayToScriptHash && scriptPubKey.IsPayToScriptHash())
{
if (!scriptSig.IsPushOnly()) // scriptSig must be literals-only
return false; // or validation fails
const valtype& pubKeySerialized = stackCopy.back();
CScript pubKey2(pubKeySerialized.begin(), pubKeySerialized.end());
popstack(stackCopy);
if (!EvalScript(stackCopy, pubKey2, txTo, nIn, nHashType))
return false;
if (stackCopy.empty())
return false;
return CastToBool(stackCopy.back());
}
return true;
}
bool SignSignature(const CKeyStore &keystore, const CTransaction& txFrom, CTransaction& txTo, unsigned int nIn, int nHashType)
{
assert(nIn < txTo.vin.size());
CTxIn& txin = txTo.vin[nIn];
assert(txin.prevout.n < txFrom.vout.size());
const CTxOut& txout = txFrom.vout[txin.prevout.n];
// Leave out the signature from the hash, since a signature can't sign itself.
// The checksig op will also drop the signatures from its hash.
uint256 hash = SignatureHash(txout.scriptPubKey, txTo, nIn, nHashType);
txnouttype whichType;
if (!Solver(keystore, txout.scriptPubKey, hash, nHashType, txin.scriptSig, whichType))
return false;
if (whichType == TX_SCRIPTHASH)
{
// Solver returns the subscript that need to be evaluated;
// the final scriptSig is the signatures from that
// and then the serialized subscript:
CScript subscript = txin.scriptSig;
// Recompute txn hash using subscript in place of scriptPubKey:
uint256 hash2 = SignatureHash(subscript, txTo, nIn, nHashType);
txnouttype subType;
if (!Solver(keystore, subscript, hash2, nHashType, txin.scriptSig, subType))
return false;
if (subType == TX_SCRIPTHASH)
return false;
txin.scriptSig << static_cast<valtype>(subscript); // Append serialized subscript
}
// Test solution
if (!VerifyScript(txin.scriptSig, txout.scriptPubKey, txTo, nIn, true, 0))
return false;
return true;
}
bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsigned int nIn, bool fValidatePayToScriptHash, int nHashType)
{
assert(nIn < txTo.vin.size());
const CTxIn& txin = txTo.vin[nIn];
if (txin.prevout.n >= txFrom.vout.size())
return false;
const CTxOut& txout = txFrom.vout[txin.prevout.n];
if (txin.prevout.hash != txFrom.GetHash())
return false;
if (!VerifyScript(txin.scriptSig, txout.scriptPubKey, txTo, nIn, fValidatePayToScriptHash, nHashType))
return false;
return true;
}
unsigned int CScript::GetSigOpCount(bool fAccurate) const
{
unsigned int n = 0;
const_iterator pc = begin();
opcodetype lastOpcode = OP_INVALIDOPCODE;
while (pc < end())
{
opcodetype opcode;
if (!GetOp(pc, opcode))
break;
if (opcode == OP_CHECKSIG || opcode == OP_CHECKSIGVERIFY)
n++;
else if (opcode == OP_CHECKMULTISIG || opcode == OP_CHECKMULTISIGVERIFY)
{
if (fAccurate && lastOpcode >= OP_1 && lastOpcode <= OP_16)
n += DecodeOP_N(lastOpcode);
else
n += 20;
}
lastOpcode = opcode;
}
return n;
}
unsigned int CScript::GetSigOpCount(const CScript& scriptSig) const
{
if (!IsPayToScriptHash())
return GetSigOpCount(true);
// This is a pay-to-script-hash scriptPubKey;
// get the last item that the scriptSig
// pushes onto the stack:
const_iterator pc = scriptSig.begin();
vector<unsigned char> data;
while (pc < scriptSig.end())
{
opcodetype opcode;
if (!scriptSig.GetOp(pc, opcode, data))
return 0;
if (opcode > OP_16)
return 0;
}
/// ... and return it's opcount:
CScript subscript(data.begin(), data.end());
return subscript.GetSigOpCount(true);
}
bool CScript::IsPayToScriptHash() const
{
// Extra-fast test for pay-to-script-hash CScripts:
return (this->size() == 23 &&
this->at(0) == OP_HASH160 &&
this->at(1) == 0x14 &&
this->at(22) == OP_EQUAL);
}
void CScript::SetBitcoinAddress(const CBitcoinAddress& address)
{
this->clear();
if (address.IsScript())
*this << OP_HASH160 << address.GetHash160() << OP_EQUAL;
else
*this << OP_DUP << OP_HASH160 << address.GetHash160() << OP_EQUALVERIFY << OP_CHECKSIG;
}
void CScript::SetMultisig(int nRequired, const std::vector<CKey>& keys)
{
this->clear();
*this << EncodeOP_N(nRequired);
BOOST_FOREACH(const CKey& key, keys)
*this << key.GetPubKey();
*this << EncodeOP_N(keys.size()) << OP_CHECKMULTISIG;
}
void CScript::SetPayToScriptHash(const CScript& subscript)
{
assert(!subscript.empty());
uint160 subscriptHash = Hash160(subscript);
this->clear();
*this << OP_HASH160 << subscriptHash << OP_EQUAL;
}