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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2013 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 "script.h"
#include "crypto/ripemd160.h"
#include "crypto/sha1.h"
#include "crypto/sha2.h"
#include "core.h"
#include "hash.h"
#include "key.h"
#include "keystore.h"
#include "random.h"
#include "sync.h"
#include "uint256.h"
#include "util.h"
#include <boost/foreach.hpp>
#include <boost/thread.hpp>
#include <boost/tuple/tuple_comparison.hpp>
#include <boost/tuple/tuple.hpp>
#include <boost/foreach.hpp>
using namespace std;
using namespace boost;
typedef vector<unsigned char> valtype;
static const valtype vchFalse(0);
static const valtype vchZero(0);
static const valtype vchTrue(1, 1);
static const CScriptNum bnZero(0);
static const CScriptNum bnOne(1);
static const CScriptNum bnFalse(0);
static const CScriptNum bnTrue(1);
bool CheckSig(vector<unsigned char> vchSig, const vector<unsigned char> &vchPubKey, const CScript &scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType, int flags);
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;
}
//
// 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_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";
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 IsCanonicalPubKey(const valtype &vchPubKey, unsigned int flags) {
if (!(flags & SCRIPT_VERIFY_STRICTENC))
return true;
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: compressed nor uncompressed");
}
return true;
}
bool IsCanonicalSignature(const valtype &vchSig, unsigned int flags) {
if (!(flags & SCRIPT_VERIFY_STRICTENC))
return true;
// 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");
unsigned char nHashType = vchSig[vchSig.size() - 1] & (~(SIGHASH_ANYONECANPAY));
if (nHashType < SIGHASH_ALL || nHashType > SIGHASH_SINGLE)
return error("Non-canonical signature: unknown hashtype byte");
if (vchSig[0] != 0x30)
return error("Non-canonical signature: wrong type");
if (vchSig[1] != vchSig.size()-3)
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+7) != 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");
if (flags & SCRIPT_VERIFY_LOW_S) {
// 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 EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, const CTransaction& txTo, unsigned int nIn, unsigned int flags, int nHashType)
{
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;
// Note how OP_RESERVED does not count towards the opcode limit.
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; // Disabled opcodes.
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)
CScriptNum 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
CScriptNum 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 = CScriptNum(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;
case OP_SIZE:
{
// (in -- in size)
if (stack.size() < 1)
return false;
CScriptNum bn(stacktop(-1).size());
stack.push_back(bn.getvch());
}
break;
//
// Bitwise logic
//
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_NEGATE:
case OP_ABS:
case OP_NOT:
case OP_0NOTEQUAL:
{
// (in -- out)
if (stack.size() < 1)
return false;
CScriptNum bn(stacktop(-1));
switch (opcode)
{
case OP_1ADD: bn += bnOne; break;
case OP_1SUB: bn -= bnOne; 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_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;
CScriptNum bn1(stacktop(-2));
CScriptNum bn2(stacktop(-1));
CScriptNum bn(0);
switch (opcode)
{
case OP_ADD:
bn = bn1 + bn2;
break;
case OP_SUB:
bn = bn1 - bn2;
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;
CScriptNum bn1(stacktop(-3));
CScriptNum bn2(stacktop(-2));
CScriptNum bn3(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)
CRIPEMD160().Write(&vch[0], vch.size()).Finalize(&vchHash[0]);
else if (opcode == OP_SHA1)
CSHA1().Write(&vch[0], vch.size()).Finalize(&vchHash[0]);
else if (opcode == OP_SHA256)
CSHA256().Write(&vch[0], vch.size()).Finalize(&vchHash[0]);
else if (opcode == OP_HASH160)
CHash160().Write(&vch[0], vch.size()).Finalize(&vchHash[0]);
else if (opcode == OP_HASH256)
CHash256().Write(&vch[0], vch.size()).Finalize(&vchHash[0]);
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);
// 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 = IsCanonicalSignature(vchSig, flags) && IsCanonicalPubKey(vchPubKey, flags) &&
CheckSig(vchSig, vchPubKey, scriptCode, txTo, nIn, nHashType, flags);
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 = CScriptNum(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 = CScriptNum(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
bool fOk = IsCanonicalSignature(vchSig, flags) && IsCanonicalPubKey(vchPubKey, flags) &&
CheckSig(vchSig, vchPubKey, scriptCode, txTo, nIn, nHashType, flags);
if (fOk) {
isig++;
nSigsCount--;
}
ikey++;
nKeysCount--;
// If there are more signatures left than keys left,
// then too many signatures have failed
if (nSigsCount > nKeysCount)
fSuccess = false;
}
// Clean up stack of actual arguments
while (i-- > 1)
popstack(stack);
// A bug causes CHECKMULTISIG to consume one extra argument
// whose contents were not checked in any way.
//
// Unfortunately this is a potential source of mutability,
// so optionally verify it is exactly equal to zero prior
// to removing it from the stack.
if (stack.size() < 1)
return false;
if ((flags & SCRIPT_VERIFY_NULLDUMMY) && stacktop(-1).size())
return error("CHECKMULTISIG dummy argument not null");
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;
}
namespace {
/** Wrapper that serializes like CTransaction, but with the modifications
* required for the signature hash done in-place
*/
class CTransactionSignatureSerializer {
private:
const CTransaction &txTo; // reference to the spending transaction (the one being serialized)
const CScript &scriptCode; // output script being consumed
const unsigned int nIn; // input index of txTo being signed
const bool fAnyoneCanPay; // whether the hashtype has the SIGHASH_ANYONECANPAY flag set
const bool fHashSingle; // whether the hashtype is SIGHASH_SINGLE
const bool fHashNone; // whether the hashtype is SIGHASH_NONE
public:
CTransactionSignatureSerializer(const CTransaction &txToIn, const CScript &scriptCodeIn, unsigned int nInIn, int nHashTypeIn) :
txTo(txToIn), scriptCode(scriptCodeIn), nIn(nInIn),
fAnyoneCanPay(!!(nHashTypeIn & SIGHASH_ANYONECANPAY)),
fHashSingle((nHashTypeIn & 0x1f) == SIGHASH_SINGLE),
fHashNone((nHashTypeIn & 0x1f) == SIGHASH_NONE) {}
/** Serialize the passed scriptCode, skipping OP_CODESEPARATORs */
template<typename S>
void SerializeScriptCode(S &s, int nType, int nVersion) const {
CScript::const_iterator it = scriptCode.begin();
CScript::const_iterator itBegin = it;
opcodetype opcode;
unsigned int nCodeSeparators = 0;
while (scriptCode.GetOp(it, opcode)) {
if (opcode == OP_CODESEPARATOR)
nCodeSeparators++;
}
::WriteCompactSize(s, scriptCode.size() - nCodeSeparators);
it = itBegin;
while (scriptCode.GetOp(it, opcode)) {
if (opcode == OP_CODESEPARATOR) {
s.write((char*)&itBegin[0], it-itBegin-1);
itBegin = it;
}
}
s.write((char*)&itBegin[0], it-itBegin);
}
/** Serialize an input of txTo */
template<typename S>
void SerializeInput(S &s, unsigned int nInput, int nType, int nVersion) const {
// In case of SIGHASH_ANYONECANPAY, only the input being signed is serialized
if (fAnyoneCanPay)
nInput = nIn;
// Serialize the prevout
::Serialize(s, txTo.vin[nInput].prevout, nType, nVersion);
// Serialize the script
if (nInput != nIn)
// Blank out other inputs' signatures
::Serialize(s, CScript(), nType, nVersion);
else
SerializeScriptCode(s, nType, nVersion);
// Serialize the nSequence
if (nInput != nIn && (fHashSingle || fHashNone))
// let the others update at will
::Serialize(s, (int)0, nType, nVersion);
else
::Serialize(s, txTo.vin[nInput].nSequence, nType, nVersion);
}
/** Serialize an output of txTo */
template<typename S>
void SerializeOutput(S &s, unsigned int nOutput, int nType, int nVersion) const {
if (fHashSingle && nOutput != nIn)
// Do not lock-in the txout payee at other indices as txin
::Serialize(s, CTxOut(), nType, nVersion);
else
::Serialize(s, txTo.vout[nOutput], nType, nVersion);
}
/** Serialize txTo */
template<typename S>
void Serialize(S &s, int nType, int nVersion) const {
// Serialize nVersion
::Serialize(s, txTo.nVersion, nType, nVersion);
// Serialize vin
unsigned int nInputs = fAnyoneCanPay ? 1 : txTo.vin.size();
::WriteCompactSize(s, nInputs);
for (unsigned int nInput = 0; nInput < nInputs; nInput++)
SerializeInput(s, nInput, nType, nVersion);
// Serialize vout
unsigned int nOutputs = fHashNone ? 0 : (fHashSingle ? nIn+1 : txTo.vout.size());
::WriteCompactSize(s, nOutputs);
for (unsigned int nOutput = 0; nOutput < nOutputs; nOutput++)
SerializeOutput(s, nOutput, nType, nVersion);
// Serialie nLockTime
::Serialize(s, txTo.nLockTime, nType, nVersion);
}
};
} // anon namespace
uint256 SignatureHash(const CScript &scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType)
{
if (nIn >= txTo.vin.size()) {
LogPrintf("ERROR: SignatureHash() : nIn=%d out of range\n", nIn);
return 1;
}
// Check for invalid use of SIGHASH_SINGLE
if ((nHashType & 0x1f) == SIGHASH_SINGLE) {
if (nIn >= txTo.vout.size()) {
LogPrintf("ERROR: SignatureHash() : nOut=%d out of range\n", nIn);
return 1;
}
}
// Wrapper to serialize only the necessary parts of the transaction being signed
CTransactionSignatureSerializer txTmp(txTo, scriptCode, nIn, nHashType);
// Serialize and hash
CHashWriter ss(SER_GETHASH, 0);
ss << txTmp << nHashType;
return ss.GetHash();
}
// Valid signature cache, to avoid doing expensive ECDSA signature checking
// twice for every transaction (once when accepted into memory pool, and
// again when accepted into the block chain)
class CSignatureCache
{
private:
// sigdata_type is (signature hash, signature, public key):
typedef boost::tuple<uint256, std::vector<unsigned char>, CPubKey> sigdata_type;
std::set< sigdata_type> setValid;
boost::shared_mutex cs_sigcache;
public:
bool
Get(const uint256 &hash, const std::vector<unsigned char>& vchSig, const CPubKey& pubKey)
{
boost::shared_lock<boost::shared_mutex> lock(cs_sigcache);
sigdata_type k(hash, vchSig, pubKey);
std::set<sigdata_type>::iterator mi = setValid.find(k);
if (mi != setValid.end())
return true;
return false;
}
void Set(const uint256 &hash, const std::vector<unsigned char>& vchSig, const CPubKey& pubKey)
{
// DoS prevention: limit cache size to less than 10MB
// (~200 bytes per cache entry times 50,000 entries)
// Since there are a maximum of 20,000 signature operations per block
// 50,000 is a reasonable default.
int64_t nMaxCacheSize = GetArg("-maxsigcachesize", 50000);
if (nMaxCacheSize <= 0) return;
boost::unique_lock<boost::shared_mutex> lock(cs_sigcache);
while (static_cast<int64_t>(setValid.size()) > nMaxCacheSize)
{
// Evict a random entry. Random because that helps
// foil would-be DoS attackers who might try to pre-generate
// and re-use a set of valid signatures just-slightly-greater
// than our cache size.
uint256 randomHash = GetRandHash();
std::vector<unsigned char> unused;
std::set<sigdata_type>::iterator it =
setValid.lower_bound(sigdata_type(randomHash, unused, unused));
if (it == setValid.end())
it = setValid.begin();
setValid.erase(*it);
}
sigdata_type k(hash, vchSig, pubKey);
setValid.insert(k);
}
};
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 CSignatureCache signatureCache;
CPubKey pubkey(vchPubKey);
if (!pubkey.IsValid())
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();
uint256 sighash = SignatureHash(scriptCode, txTo, nIn, nHashType);
if (signatureCache.Get(sighash, vchSig, pubkey))
return true;
if (!pubkey.Verify(sighash, vchSig))
return false;
if (!(flags & SCRIPT_VERIFY_NOCACHE))
signatureCache.Set(sighash, vchSig, pubkey);
return true;
}
//
// 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 multimap<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));
// Empty, provably prunable, data-carrying output
if (GetBoolArg("-datacarrier", true))
mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN << OP_SMALLDATA));
mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN));
}
// 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();
while (true)
{
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() <= 65)
{
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 statements
}
if (opcode2 == OP_PUBKEY)
{
if (vch1.size() < 33 || vch1.size() > 65)
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 (opcode2 == OP_SMALLDATA)
{
// small pushdata, <= MAX_OP_RETURN_RELAY bytes
if (vch1.size() > MAX_OP_RETURN_RELAY)
break;
}
else if (opcode1 != opcode2 || vch1 != vch2)
{
// Others must match exactly
break;
}
}
}
vSolutionsRet.clear();
typeRet = TX_NONSTANDARD;
return false;
}
bool Sign1(const CKeyID& 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 (unsigned int i = 1; i < multisigdata.size()-1 && nSigned < nRequired; i++)
{
const valtype& pubkey = multisigdata[i];
CKeyID keyID = CPubKey(pubkey).GetID();
if (Sign1(keyID, keystore, hash, nHashType, scriptSigRet))
++nSigned;
}
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 satisfied.
//
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;
CKeyID keyID;
switch (whichTypeRet)
{
case TX_NONSTANDARD:
case TX_NULL_DATA:
return false;
case TX_PUBKEY:
keyID = CPubKey(vSolutions[0]).GetID();
return Sign1(keyID, keystore, hash, nHashType, scriptSigRet);
case TX_PUBKEYHASH:
keyID = CKeyID(uint160(vSolutions[0]));
if (!Sign1(keyID, keystore, hash, nHashType, scriptSigRet))
return false;
else
{
CPubKey vch;
keystore.GetPubKey(keyID, 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:
case TX_NULL_DATA:
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, txnouttype& whichType)
{
vector<valtype> vSolutions;
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)
{
CKeyID keyID = CPubKey(pubkey).GetID();
if (keystore.HaveKey(keyID))
++nResult;
}
return nResult;
}
isminetype IsMine(const CKeyStore &keystore, const CTxDestination& dest)
{
CScript script;
script.SetDestination(dest);
return IsMine(keystore, script);
}
isminetype IsMine(const CKeyStore &keystore, const CScript& scriptPubKey)
{
vector<valtype> vSolutions;
txnouttype whichType;
if (!Solver(scriptPubKey, whichType, vSolutions)) {
if (keystore.HaveWatchOnly(scriptPubKey))
return ISMINE_WATCH_ONLY;
return ISMINE_NO;
}
CKeyID keyID;
switch (whichType)
{
case TX_NONSTANDARD:
case TX_NULL_DATA:
break;
case TX_PUBKEY:
keyID = CPubKey(vSolutions[0]).GetID();
if (keystore.HaveKey(keyID))
return ISMINE_SPENDABLE;
break;
case TX_PUBKEYHASH:
keyID = CKeyID(uint160(vSolutions[0]));
if (keystore.HaveKey(keyID))
return ISMINE_SPENDABLE;
break;
case TX_SCRIPTHASH:
{
CScriptID scriptID = CScriptID(uint160(vSolutions[0]));
CScript subscript;
if (keystore.GetCScript(scriptID, subscript)) {
isminetype ret = IsMine(keystore, subscript);
if (ret == ISMINE_SPENDABLE)
return ret;
}
break;
}
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);
if (HaveKeys(keys, keystore) == keys.size())
return ISMINE_SPENDABLE;
break;
}
}
if (keystore.HaveWatchOnly(scriptPubKey))
return ISMINE_WATCH_ONLY;
return ISMINE_NO;
}
bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
{
vector<valtype> vSolutions;
txnouttype whichType;
if (!Solver(scriptPubKey, whichType, vSolutions))
return false;
if (whichType == TX_PUBKEY)
{
addressRet = CPubKey(vSolutions[0]).GetID();
return true;
}
else if (whichType == TX_PUBKEYHASH)
{
addressRet = CKeyID(uint160(vSolutions[0]));
return true;
}
else if (whichType == TX_SCRIPTHASH)
{
addressRet = CScriptID(uint160(vSolutions[0]));
return true;
}
// Multisig txns have more than one address...
return false;
}
bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, vector<CTxDestination>& addressRet, int& nRequiredRet)
{
addressRet.clear();
typeRet = TX_NONSTANDARD;
vector<valtype> vSolutions;
if (!Solver(scriptPubKey, typeRet, vSolutions))
return false;
if (typeRet == TX_NULL_DATA){
// This is data, not addresses
return false;
}
if (typeRet == TX_MULTISIG)
{
nRequiredRet = vSolutions.front()[0];
for (unsigned int i = 1; i < vSolutions.size()-1; i++)
{
CTxDestination address = CPubKey(vSolutions[i]).GetID();
addressRet.push_back(address);
}
}
else
{
nRequiredRet = 1;
CTxDestination address;
if (!ExtractDestination(scriptPubKey, address))
return false;
addressRet.push_back(address);
}
return true;
}
class CAffectedKeysVisitor : public boost::static_visitor<void> {
private:
const CKeyStore &keystore;
std::vector<CKeyID> &vKeys;
public:
CAffectedKeysVisitor(const CKeyStore &keystoreIn, std::vector<CKeyID> &vKeysIn) : keystore(keystoreIn), vKeys(vKeysIn) {}
void Process(const CScript &script) {
txnouttype type;
std::vector<CTxDestination> vDest;
int nRequired;
if (ExtractDestinations(script, type, vDest, nRequired)) {
BOOST_FOREACH(const CTxDestination &dest, vDest)
boost::apply_visitor(*this, dest);
}
}
void operator()(const CKeyID &keyId) {
if (keystore.HaveKey(keyId))
vKeys.push_back(keyId);
}
void operator()(const CScriptID &scriptId) {
CScript script;
if (keystore.GetCScript(scriptId, script))
Process(script);
}
void operator()(const CNoDestination &none) {}
};
void ExtractAffectedKeys(const CKeyStore &keystore, const CScript& scriptPubKey, std::vector<CKeyID> &vKeys) {
CAffectedKeysVisitor(keystore, vKeys).Process(scriptPubKey);
}
bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, const CTransaction& txTo, unsigned int nIn,
unsigned int flags, int nHashType)
{
vector<vector<unsigned char> > stack, stackCopy;
if (!EvalScript(stack, scriptSig, txTo, nIn, flags, nHashType))
return false;
if (flags & SCRIPT_VERIFY_P2SH)
stackCopy = stack;
if (!EvalScript(stack, scriptPubKey, txTo, nIn, flags, nHashType))
return false;
if (stack.empty())
return false;
if (CastToBool(stack.back()) == false)
return false;
// Additional validation for spend-to-script-hash transactions:
if ((flags & SCRIPT_VERIFY_P2SH) && scriptPubKey.IsPayToScriptHash())
{
if (!scriptSig.IsPushOnly()) // scriptSig must be literals-only
return false; // or validation fails
// stackCopy cannot be empty here, because if it was the
// P2SH HASH <> EQUAL scriptPubKey would be evaluated with
// an empty stack and the EvalScript above would return false.
assert(!stackCopy.empty());
const valtype& pubKeySerialized = stackCopy.back();
CScript pubKey2(pubKeySerialized.begin(), pubKeySerialized.end());
popstack(stackCopy);
if (!EvalScript(stackCopy, pubKey2, txTo, nIn, flags, nHashType))
return false;
if (stackCopy.empty())
return false;
return CastToBool(stackCopy.back());
}
return true;
}
bool SignSignature(const CKeyStore &keystore, const CScript& fromPubKey, CMutableTransaction& txTo, unsigned int nIn, int nHashType)
{
assert(nIn < txTo.vin.size());
CTxIn& txin = txTo.vin[nIn];
// 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(fromPubKey, txTo, nIn, nHashType);
txnouttype whichType;
if (!Solver(keystore, fromPubKey, 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;
bool fSolved =
Solver(keystore, subscript, hash2, nHashType, txin.scriptSig, subType) && subType != TX_SCRIPTHASH;
// Append serialized subscript whether or not it is completely signed:
txin.scriptSig << static_cast<valtype>(subscript);
if (!fSolved) return false;
}
// Test solution
return VerifyScript(txin.scriptSig, fromPubKey, txTo, nIn, STANDARD_SCRIPT_VERIFY_FLAGS, 0);
}
bool SignSignature(const CKeyStore &keystore, const CTransaction& txFrom, CMutableTransaction& 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];
return SignSignature(keystore, txout.scriptPubKey, txTo, nIn, nHashType);
}
static CScript PushAll(const vector<valtype>& values)
{
CScript result;
BOOST_FOREACH(const valtype& v, values)
result << v;
return result;
}
static CScript CombineMultisig(CScript scriptPubKey, const CMutableTransaction& txTo, unsigned int nIn,
const vector<valtype>& vSolutions,
vector<valtype>& sigs1, vector<valtype>& sigs2)
{
// Combine all the signatures we've got:
set<valtype> allsigs;
BOOST_FOREACH(const valtype& v, sigs1)
{
if (!v.empty())
allsigs.insert(v);
}
BOOST_FOREACH(const valtype& v, sigs2)
{
if (!v.empty())
allsigs.insert(v);
}
// Build a map of pubkey -> signature by matching sigs to pubkeys:
assert(vSolutions.size() > 1);
unsigned int nSigsRequired = vSolutions.front()[0];
unsigned int nPubKeys = vSolutions.size()-2;
map<valtype, valtype> sigs;
BOOST_FOREACH(const valtype& sig, allsigs)
{
for (unsigned int i = 0; i < nPubKeys; i++)
{
const valtype& pubkey = vSolutions[i+1];
if (sigs.count(pubkey))
continue; // Already got a sig for this pubkey
if (CheckSig(sig, pubkey, scriptPubKey, txTo, nIn, 0, 0))
{
sigs[pubkey] = sig;
break;
}
}
}
// Now build a merged CScript:
unsigned int nSigsHave = 0;
CScript result; result << OP_0; // pop-one-too-many workaround
for (unsigned int i = 0; i < nPubKeys && nSigsHave < nSigsRequired; i++)
{
if (sigs.count(vSolutions[i+1]))
{
result << sigs[vSolutions[i+1]];
++nSigsHave;
}
}
// Fill any missing with OP_0:
for (unsigned int i = nSigsHave; i < nSigsRequired; i++)
result << OP_0;
return result;
}
static CScript CombineSignatures(CScript scriptPubKey, const CTransaction& txTo, unsigned int nIn,
const txnouttype txType, const vector<valtype>& vSolutions,
vector<valtype>& sigs1, vector<valtype>& sigs2)
{
switch (txType)
{
case TX_NONSTANDARD:
case TX_NULL_DATA:
// Don't know anything about this, assume bigger one is correct:
if (sigs1.size() >= sigs2.size())
return PushAll(sigs1);
return PushAll(sigs2);
case TX_PUBKEY:
case TX_PUBKEYHASH:
// Signatures are bigger than placeholders or empty scripts:
if (sigs1.empty() || sigs1[0].empty())
return PushAll(sigs2);
return PushAll(sigs1);
case TX_SCRIPTHASH:
if (sigs1.empty() || sigs1.back().empty())
return PushAll(sigs2);
else if (sigs2.empty() || sigs2.back().empty())
return PushAll(sigs1);
else
{
// Recur to combine:
valtype spk = sigs1.back();
CScript pubKey2(spk.begin(), spk.end());
txnouttype txType2;
vector<vector<unsigned char> > vSolutions2;
Solver(pubKey2, txType2, vSolutions2);
sigs1.pop_back();
sigs2.pop_back();
CScript result = CombineSignatures(pubKey2, txTo, nIn, txType2, vSolutions2, sigs1, sigs2);
result << spk;
return result;
}
case TX_MULTISIG:
return CombineMultisig(scriptPubKey, txTo, nIn, vSolutions, sigs1, sigs2);
}
return CScript();
}
CScript CombineSignatures(CScript scriptPubKey, const CTransaction& txTo, unsigned int nIn,
const CScript& scriptSig1, const CScript& scriptSig2)
{
txnouttype txType;
vector<vector<unsigned char> > vSolutions;
Solver(scriptPubKey, txType, vSolutions);
vector<valtype> stack1;
EvalScript(stack1, scriptSig1, CTransaction(), 0, SCRIPT_VERIFY_STRICTENC, 0);
vector<valtype> stack2;
EvalScript(stack2, scriptSig2, CTransaction(), 0, SCRIPT_VERIFY_STRICTENC, 0);
return CombineSignatures(scriptPubKey, txTo, nIn, txType, vSolutions, stack1, stack2);
}
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 its 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);
}
bool CScript::IsPushOnly() const
{
const_iterator pc = begin();
while (pc < end())
{
// Note how a script with an invalid PUSHDATA returns False.
opcodetype opcode;
if (!GetOp(pc, opcode))
return false;
// Note that IsPushOnly() *does* consider OP_RESERVED to be a
// push-type opcode, however execution of OP_RESERVED fails, so
// it's not relevant to P2SH as the scriptSig would fail prior to
// the P2SH special validation code being executed.
if (opcode > OP_16)
return false;
}
return true;
}
bool CScript::HasCanonicalPushes() const
{
const_iterator pc = begin();
while (pc < end())
{
opcodetype opcode;
std::vector<unsigned char> data;
if (!GetOp(pc, opcode, data))
return false;
if (opcode > OP_16)
continue;
if (opcode < OP_PUSHDATA1 && opcode > OP_0 && (data.size() == 1 && data[0] <= 16))
// Could have used an OP_n code, rather than a 1-byte push.
return false;
if (opcode == OP_PUSHDATA1 && data.size() < OP_PUSHDATA1)
// Could have used a normal n-byte push, rather than OP_PUSHDATA1.
return false;
if (opcode == OP_PUSHDATA2 && data.size() <= 0xFF)
// Could have used an OP_PUSHDATA1.
return false;
if (opcode == OP_PUSHDATA4 && data.size() <= 0xFFFF)
// Could have used an OP_PUSHDATA2.
return false;
}
return true;
}
class CScriptVisitor : public boost::static_visitor<bool>
{
private:
CScript *script;
public:
CScriptVisitor(CScript *scriptin) { script = scriptin; }
bool operator()(const CNoDestination &dest) const {
script->clear();
return false;
}
bool operator()(const CKeyID &keyID) const {
script->clear();
*script << OP_DUP << OP_HASH160 << keyID << OP_EQUALVERIFY << OP_CHECKSIG;
return true;
}
bool operator()(const CScriptID &scriptID) const {
script->clear();
*script << OP_HASH160 << scriptID << OP_EQUAL;
return true;
}
};
void CScript::SetDestination(const CTxDestination& dest)
{
boost::apply_visitor(CScriptVisitor(this), dest);
}
void CScript::SetMultisig(int nRequired, const std::vector<CPubKey>& keys)
{
this->clear();
*this << EncodeOP_N(nRequired);
BOOST_FOREACH(const CPubKey& key, keys)
*this << key;
*this << EncodeOP_N(keys.size()) << OP_CHECKMULTISIG;
}
bool CScriptCompressor::IsToKeyID(CKeyID &hash) const
{
if (script.size() == 25 && script[0] == OP_DUP && script[1] == OP_HASH160
&& script[2] == 20 && script[23] == OP_EQUALVERIFY
&& script[24] == OP_CHECKSIG) {
memcpy(&hash, &script[3], 20);
return true;
}
return false;
}
bool CScriptCompressor::IsToScriptID(CScriptID &hash) const
{
if (script.size() == 23 && script[0] == OP_HASH160 && script[1] == 20
&& script[22] == OP_EQUAL) {
memcpy(&hash, &script[2], 20);
return true;
}
return false;
}
bool CScriptCompressor::IsToPubKey(CPubKey &pubkey) const
{
if (script.size() == 35 && script[0] == 33 && script[34] == OP_CHECKSIG
&& (script[1] == 0x02 || script[1] == 0x03)) {
pubkey.Set(&script[1], &script[34]);
return true;
}
if (script.size() == 67 && script[0] == 65 && script[66] == OP_CHECKSIG
&& script[1] == 0x04) {
pubkey.Set(&script[1], &script[66]);
return pubkey.IsFullyValid(); // if not fully valid, a case that would not be compressible
}
return false;
}
bool CScriptCompressor::Compress(std::vector<unsigned char> &out) const
{
CKeyID keyID;
if (IsToKeyID(keyID)) {
out.resize(21);
out[0] = 0x00;
memcpy(&out[1], &keyID, 20);
return true;
}
CScriptID scriptID;
if (IsToScriptID(scriptID)) {
out.resize(21);
out[0] = 0x01;
memcpy(&out[1], &scriptID, 20);
return true;
}
CPubKey pubkey;
if (IsToPubKey(pubkey)) {
out.resize(33);
memcpy(&out[1], &pubkey[1], 32);
if (pubkey[0] == 0x02 || pubkey[0] == 0x03) {
out[0] = pubkey[0];
return true;
} else if (pubkey[0] == 0x04) {
out[0] = 0x04 | (pubkey[64] & 0x01);
return true;
}
}
return false;
}
unsigned int CScriptCompressor::GetSpecialSize(unsigned int nSize) const
{
if (nSize == 0 || nSize == 1)
return 20;
if (nSize == 2 || nSize == 3 || nSize == 4 || nSize == 5)
return 32;
return 0;
}
bool CScriptCompressor::Decompress(unsigned int nSize, const std::vector<unsigned char> &in)
{
switch(nSize) {
case 0x00:
script.resize(25);
script[0] = OP_DUP;
script[1] = OP_HASH160;
script[2] = 20;
memcpy(&script[3], &in[0], 20);
script[23] = OP_EQUALVERIFY;
script[24] = OP_CHECKSIG;
return true;
case 0x01:
script.resize(23);
script[0] = OP_HASH160;
script[1] = 20;
memcpy(&script[2], &in[0], 20);
script[22] = OP_EQUAL;
return true;
case 0x02:
case 0x03:
script.resize(35);
script[0] = 33;
script[1] = nSize;
memcpy(&script[2], &in[0], 32);
script[34] = OP_CHECKSIG;
return true;
case 0x04:
case 0x05:
unsigned char vch[33] = {};
vch[0] = nSize - 2;
memcpy(&vch[1], &in[0], 32);
CPubKey pubkey(&vch[0], &vch[33]);
if (!pubkey.Decompress())
return false;
assert(pubkey.size() == 65);
script.resize(67);
script[0] = 65;
memcpy(&script[1], pubkey.begin(), 65);
script[66] = OP_CHECKSIG;
return true;
}
return false;
}