Update README now that main svn has -testnet built in
[novacoin.git] / script.cpp
index 98f5afd..a09031b 100644 (file)
-// Copyright (c) 2009-2010 Satoshi Nakamoto\r
-// Distributed under the MIT/X11 software license, see the accompanying\r
-// file license.txt or http://www.opensource.org/licenses/mit-license.php.\r
-\r
-#include "headers.h"\r
-\r
-bool CheckSig(vector<unsigned char> vchSig, vector<unsigned char> vchPubKey, CScript scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType);\r
-\r
-\r
-\r
-typedef vector<unsigned char> valtype;\r
-static const valtype vchFalse(0);\r
-static const valtype vchZero(0);\r
-static const valtype vchTrue(1, 1);\r
-static const CBigNum bnZero(0);\r
-static const CBigNum bnOne(1);\r
-static const CBigNum bnFalse(0);\r
-static const CBigNum bnTrue(1);\r
-\r
-\r
-bool CastToBool(const valtype& vch)\r
-{\r
-    return (CBigNum(vch) != bnZero);\r
-}\r
-\r
-void MakeSameSize(valtype& vch1, valtype& vch2)\r
-{\r
-    // Lengthen the shorter one\r
-    if (vch1.size() < vch2.size())\r
-        vch1.resize(vch2.size(), 0);\r
-    if (vch2.size() < vch1.size())\r
-        vch2.resize(vch1.size(), 0);\r
-}\r
-\r
-\r
-\r
-//\r
-// Script is a stack machine (like Forth) that evaluates a predicate\r
-// returning a bool indicating valid or not.  There are no loops.\r
-//\r
-#define stacktop(i)  (stack.at(stack.size()+(i)))\r
-#define altstacktop(i)  (altstack.at(altstack.size()+(i)))\r
-\r
-bool EvalScript(const CScript& script, const CTransaction& txTo, unsigned int nIn, int nHashType,\r
-                vector<vector<unsigned char> >* pvStackRet)\r
-{\r
-    CAutoBN_CTX pctx;\r
-    CScript::const_iterator pc = script.begin();\r
-    CScript::const_iterator pend = script.end();\r
-    CScript::const_iterator pbegincodehash = script.begin();\r
-    vector<bool> vfExec;\r
-    vector<valtype> stack;\r
-    vector<valtype> altstack;\r
-    if (pvStackRet)\r
-        pvStackRet->clear();\r
-\r
-\r
-    while (pc < pend)\r
-    {\r
-        bool fExec = !count(vfExec.begin(), vfExec.end(), false);\r
-\r
-        //\r
-        // Read instruction\r
-        //\r
-        opcodetype opcode;\r
-        valtype vchPushValue;\r
-        if (!script.GetOp(pc, opcode, vchPushValue))\r
-            return false;\r
-\r
-        if (fExec && opcode <= OP_PUSHDATA4)\r
-            stack.push_back(vchPushValue);\r
-        else if (fExec || (OP_IF <= opcode && opcode <= OP_ENDIF))\r
-        switch (opcode)\r
-        {\r
-            //\r
-            // Push value\r
-            //\r
-            case OP_1NEGATE:\r
-            case OP_1:\r
-            case OP_2:\r
-            case OP_3:\r
-            case OP_4:\r
-            case OP_5:\r
-            case OP_6:\r
-            case OP_7:\r
-            case OP_8:\r
-            case OP_9:\r
-            case OP_10:\r
-            case OP_11:\r
-            case OP_12:\r
-            case OP_13:\r
-            case OP_14:\r
-            case OP_15:\r
-            case OP_16:\r
-            {\r
-                // ( -- value)\r
-                CBigNum bn((int)opcode - (int)(OP_1 - 1));\r
-                stack.push_back(bn.getvch());\r
-            }\r
-            break;\r
-\r
-\r
-            //\r
-            // Control\r
-            //\r
-            case OP_NOP:\r
-            break;\r
-\r
-            case OP_VER:\r
-            {\r
-                CBigNum bn(VERSION);\r
-                stack.push_back(bn.getvch());\r
-            }\r
-            break;\r
-\r
-            case OP_IF:\r
-            case OP_NOTIF:\r
-            case OP_VERIF:\r
-            case OP_VERNOTIF:\r
-            {\r
-                // <expression> if [statements] [else [statements]] endif\r
-                bool fValue = false;\r
-                if (fExec)\r
-                {\r
-                    if (stack.size() < 1)\r
-                        return false;\r
-                    valtype& vch = stacktop(-1);\r
-                    if (opcode == OP_VERIF || opcode == OP_VERNOTIF)\r
-                        fValue = (CBigNum(VERSION) >= CBigNum(vch));\r
-                    else\r
-                        fValue = CastToBool(vch);\r
-                    if (opcode == OP_NOTIF || opcode == OP_VERNOTIF)\r
-                        fValue = !fValue;\r
-                    stack.pop_back();\r
-                }\r
-                vfExec.push_back(fValue);\r
-            }\r
-            break;\r
-\r
-            case OP_ELSE:\r
-            {\r
-                if (vfExec.empty())\r
-                    return false;\r
-                vfExec.back() = !vfExec.back();\r
-            }\r
-            break;\r
-\r
-            case OP_ENDIF:\r
-            {\r
-                if (vfExec.empty())\r
-                    return false;\r
-                vfExec.pop_back();\r
-            }\r
-            break;\r
-\r
-            case OP_VERIFY:\r
-            {\r
-                // (true -- ) or\r
-                // (false -- false) and return\r
-                if (stack.size() < 1)\r
-                    return false;\r
-                bool fValue = CastToBool(stacktop(-1));\r
-                if (fValue)\r
-                    stack.pop_back();\r
-                else\r
-                    pc = pend;\r
-            }\r
-            break;\r
-\r
-            case OP_RETURN:\r
-            {\r
-                pc = pend;\r
-            }\r
-            break;\r
-\r
-\r
-            //\r
-            // Stack ops\r
-            //\r
-            case OP_TOALTSTACK:\r
-            {\r
-                if (stack.size() < 1)\r
-                    return false;\r
-                altstack.push_back(stacktop(-1));\r
-                stack.pop_back();\r
-            }\r
-            break;\r
-\r
-            case OP_FROMALTSTACK:\r
-            {\r
-                if (altstack.size() < 1)\r
-                    return false;\r
-                stack.push_back(altstacktop(-1));\r
-                altstack.pop_back();\r
-            }\r
-            break;\r
-\r
-            case OP_2DROP:\r
-            {\r
-                // (x1 x2 -- )\r
-                stack.pop_back();\r
-                stack.pop_back();\r
-            }\r
-            break;\r
-\r
-            case OP_2DUP:\r
-            {\r
-                // (x1 x2 -- x1 x2 x1 x2)\r
-                if (stack.size() < 2)\r
-                    return false;\r
-                valtype vch1 = stacktop(-2);\r
-                valtype vch2 = stacktop(-1);\r
-                stack.push_back(vch1);\r
-                stack.push_back(vch2);\r
-            }\r
-            break;\r
-\r
-            case OP_3DUP:\r
-            {\r
-                // (x1 x2 x3 -- x1 x2 x3 x1 x2 x3)\r
-                if (stack.size() < 3)\r
-                    return false;\r
-                valtype vch1 = stacktop(-3);\r
-                valtype vch2 = stacktop(-2);\r
-                valtype vch3 = stacktop(-1);\r
-                stack.push_back(vch1);\r
-                stack.push_back(vch2);\r
-                stack.push_back(vch3);\r
-            }\r
-            break;\r
-\r
-            case OP_2OVER:\r
-            {\r
-                // (x1 x2 x3 x4 -- x1 x2 x3 x4 x1 x2)\r
-                if (stack.size() < 4)\r
-                    return false;\r
-                valtype vch1 = stacktop(-4);\r
-                valtype vch2 = stacktop(-3);\r
-                stack.push_back(vch1);\r
-                stack.push_back(vch2);\r
-            }\r
-            break;\r
-\r
-            case OP_2ROT:\r
-            {\r
-                // (x1 x2 x3 x4 x5 x6 -- x3 x4 x5 x6 x1 x2)\r
-                if (stack.size() < 6)\r
-                    return false;\r
-                valtype vch1 = stacktop(-6);\r
-                valtype vch2 = stacktop(-5);\r
-                stack.erase(stack.end()-6, stack.end()-4);\r
-                stack.push_back(vch1);\r
-                stack.push_back(vch2);\r
-            }\r
-            break;\r
-\r
-            case OP_2SWAP:\r
-            {\r
-                // (x1 x2 x3 x4 -- x3 x4 x1 x2)\r
-                if (stack.size() < 4)\r
-                    return false;\r
-                swap(stacktop(-4), stacktop(-2));\r
-                swap(stacktop(-3), stacktop(-1));\r
-            }\r
-            break;\r
-\r
-            case OP_IFDUP:\r
-            {\r
-                // (x - 0 | x x)\r
-                if (stack.size() < 1)\r
-                    return false;\r
-                valtype vch = stacktop(-1);\r
-                if (CastToBool(vch))\r
-                    stack.push_back(vch);\r
-            }\r
-            break;\r
-\r
-            case OP_DEPTH:\r
-            {\r
-                // -- stacksize\r
-                CBigNum bn(stack.size());\r
-                stack.push_back(bn.getvch());\r
-            }\r
-            break;\r
-\r
-            case OP_DROP:\r
-            {\r
-                // (x -- )\r
-                if (stack.size() < 1)\r
-                    return false;\r
-                stack.pop_back();\r
-            }\r
-            break;\r
-\r
-            case OP_DUP:\r
-            {\r
-                // (x -- x x)\r
-                if (stack.size() < 1)\r
-                    return false;\r
-                valtype vch = stacktop(-1);\r
-                stack.push_back(vch);\r
-            }\r
-            break;\r
-\r
-            case OP_NIP:\r
-            {\r
-                // (x1 x2 -- x2)\r
-                if (stack.size() < 2)\r
-                    return false;\r
-                stack.erase(stack.end() - 2);\r
-            }\r
-            break;\r
-\r
-            case OP_OVER:\r
-            {\r
-                // (x1 x2 -- x1 x2 x1)\r
-                if (stack.size() < 2)\r
-                    return false;\r
-                valtype vch = stacktop(-2);\r
-                stack.push_back(vch);\r
-            }\r
-            break;\r
-\r
-            case OP_PICK:\r
-            case OP_ROLL:\r
-            {\r
-                // (xn ... x2 x1 x0 n - xn ... x2 x1 x0 xn)\r
-                // (xn ... x2 x1 x0 n - ... x2 x1 x0 xn)\r
-                if (stack.size() < 2)\r
-                    return false;\r
-                int n = CBigNum(stacktop(-1)).getint();\r
-                stack.pop_back();\r
-                if (n < 0 || n >= stack.size())\r
-                    return false;\r
-                valtype vch = stacktop(-n-1);\r
-                if (opcode == OP_ROLL)\r
-                    stack.erase(stack.end()-n-1);\r
-                stack.push_back(vch);\r
-            }\r
-            break;\r
-\r
-            case OP_ROT:\r
-            {\r
-                // (x1 x2 x3 -- x2 x3 x1)\r
-                //  x2 x1 x3  after first swap\r
-                //  x2 x3 x1  after second swap\r
-                if (stack.size() < 3)\r
-                    return false;\r
-                swap(stacktop(-3), stacktop(-2));\r
-                swap(stacktop(-2), stacktop(-1));\r
-            }\r
-            break;\r
-\r
-            case OP_SWAP:\r
-            {\r
-                // (x1 x2 -- x2 x1)\r
-                if (stack.size() < 2)\r
-                    return false;\r
-                swap(stacktop(-2), stacktop(-1));\r
-            }\r
-            break;\r
-\r
-            case OP_TUCK:\r
-            {\r
-                // (x1 x2 -- x2 x1 x2)\r
-                if (stack.size() < 2)\r
-                    return false;\r
-                valtype vch = stacktop(-1);\r
-                stack.insert(stack.end()-2, vch);\r
-            }\r
-            break;\r
-\r
-\r
-            //\r
-            // Splice ops\r
-            //\r
-            case OP_CAT:\r
-            {\r
-                // (x1 x2 -- out)\r
-                if (stack.size() < 2)\r
-                    return false;\r
-                valtype& vch1 = stacktop(-2);\r
-                valtype& vch2 = stacktop(-1);\r
-                vch1.insert(vch1.end(), vch2.begin(), vch2.end());\r
-                stack.pop_back();\r
-            }\r
-            break;\r
-\r
-            case OP_SUBSTR:\r
-            {\r
-                // (in begin size -- out)\r
-                if (stack.size() < 3)\r
-                    return false;\r
-                valtype& vch = stacktop(-3);\r
-                int nBegin = CBigNum(stacktop(-2)).getint();\r
-                int nEnd = nBegin + CBigNum(stacktop(-1)).getint();\r
-                if (nBegin < 0 || nEnd < nBegin)\r
-                    return false;\r
-                if (nBegin > vch.size())\r
-                    nBegin = vch.size();\r
-                if (nEnd > vch.size())\r
-                    nEnd = vch.size();\r
-                vch.erase(vch.begin() + nEnd, vch.end());\r
-                vch.erase(vch.begin(), vch.begin() + nBegin);\r
-                stack.pop_back();\r
-                stack.pop_back();\r
-            }\r
-            break;\r
-\r
-            case OP_LEFT:\r
-            case OP_RIGHT:\r
-            {\r
-                // (in size -- out)\r
-                if (stack.size() < 2)\r
-                    return false;\r
-                valtype& vch = stacktop(-2);\r
-                int nSize = CBigNum(stacktop(-1)).getint();\r
-                if (nSize < 0)\r
-                    return false;\r
-                if (nSize > vch.size())\r
-                    nSize = vch.size();\r
-                if (opcode == OP_LEFT)\r
-                    vch.erase(vch.begin() + nSize, vch.end());\r
-                else\r
-                    vch.erase(vch.begin(), vch.end() - nSize);\r
-                stack.pop_back();\r
-            }\r
-            break;\r
-\r
-            case OP_SIZE:\r
-            {\r
-                // (in -- in size)\r
-                if (stack.size() < 1)\r
-                    return false;\r
-                CBigNum bn(stacktop(-1).size());\r
-                stack.push_back(bn.getvch());\r
-            }\r
-            break;\r
-\r
-\r
-            //\r
-            // Bitwise logic\r
-            //\r
-            case OP_INVERT:\r
-            {\r
-                // (in - out)\r
-                if (stack.size() < 1)\r
-                    return false;\r
-                valtype& vch = stacktop(-1);\r
-                for (int i = 0; i < vch.size(); i++)\r
-                    vch[i] = ~vch[i];\r
-            }\r
-            break;\r
-\r
-            case OP_AND:\r
-            case OP_OR:\r
-            case OP_XOR:\r
-            {\r
-                // (x1 x2 - out)\r
-                if (stack.size() < 2)\r
-                    return false;\r
-                valtype& vch1 = stacktop(-2);\r
-                valtype& vch2 = stacktop(-1);\r
-                MakeSameSize(vch1, vch2);\r
-                if (opcode == OP_AND)\r
-                {\r
-                    for (int i = 0; i < vch1.size(); i++)\r
-                        vch1[i] &= vch2[i];\r
-                }\r
-                else if (opcode == OP_OR)\r
-                {\r
-                    for (int i = 0; i < vch1.size(); i++)\r
-                        vch1[i] |= vch2[i];\r
-                }\r
-                else if (opcode == OP_XOR)\r
-                {\r
-                    for (int i = 0; i < vch1.size(); i++)\r
-                        vch1[i] ^= vch2[i];\r
-                }\r
-                stack.pop_back();\r
-            }\r
-            break;\r
-\r
-            case OP_EQUAL:\r
-            case OP_EQUALVERIFY:\r
-            //case OP_NOTEQUAL: // use OP_NUMNOTEQUAL\r
-            {\r
-                // (x1 x2 - bool)\r
-                if (stack.size() < 2)\r
-                    return false;\r
-                valtype& vch1 = stacktop(-2);\r
-                valtype& vch2 = stacktop(-1);\r
-                bool fEqual = (vch1 == vch2);\r
-                // OP_NOTEQUAL is disabled because it would be too easy to say\r
-                // something like n != 1 and have some wiseguy pass in 1 with extra\r
-                // zero bytes after it (numerically, 0x01 == 0x0001 == 0x000001)\r
-                //if (opcode == OP_NOTEQUAL)\r
-                //    fEqual = !fEqual;\r
-                stack.pop_back();\r
-                stack.pop_back();\r
-                stack.push_back(fEqual ? vchTrue : vchFalse);\r
-                if (opcode == OP_EQUALVERIFY)\r
-                {\r
-                    if (fEqual)\r
-                        stack.pop_back();\r
-                    else\r
-                        pc = pend;\r
-                }\r
-            }\r
-            break;\r
-\r
-\r
-            //\r
-            // Numeric\r
-            //\r
-            case OP_1ADD:\r
-            case OP_1SUB:\r
-            case OP_2MUL:\r
-            case OP_2DIV:\r
-            case OP_NEGATE:\r
-            case OP_ABS:\r
-            case OP_NOT:\r
-            case OP_0NOTEQUAL:\r
-            {\r
-                // (in -- out)\r
-                if (stack.size() < 1)\r
-                    return false;\r
-                CBigNum bn(stacktop(-1));\r
-                switch (opcode)\r
-                {\r
-                case OP_1ADD:       bn += bnOne; break;\r
-                case OP_1SUB:       bn -= bnOne; break;\r
-                case OP_2MUL:       bn <<= 1; break;\r
-                case OP_2DIV:       bn >>= 1; break;\r
-                case OP_NEGATE:     bn = -bn; break;\r
-                case OP_ABS:        if (bn < bnZero) bn = -bn; break;\r
-                case OP_NOT:        bn = (bn == bnZero); break;\r
-                case OP_0NOTEQUAL:  bn = (bn != bnZero); break;\r
-                }\r
-                stack.pop_back();\r
-                stack.push_back(bn.getvch());\r
-            }\r
-            break;\r
-\r
-            case OP_ADD:\r
-            case OP_SUB:\r
-            case OP_MUL:\r
-            case OP_DIV:\r
-            case OP_MOD:\r
-            case OP_LSHIFT:\r
-            case OP_RSHIFT:\r
-            case OP_BOOLAND:\r
-            case OP_BOOLOR:\r
-            case OP_NUMEQUAL:\r
-            case OP_NUMEQUALVERIFY:\r
-            case OP_NUMNOTEQUAL:\r
-            case OP_LESSTHAN:\r
-            case OP_GREATERTHAN:\r
-            case OP_LESSTHANOREQUAL:\r
-            case OP_GREATERTHANOREQUAL:\r
-            case OP_MIN:\r
-            case OP_MAX:\r
-            {\r
-                // (x1 x2 -- out)\r
-                if (stack.size() < 2)\r
-                    return false;\r
-                CBigNum bn1(stacktop(-2));\r
-                CBigNum bn2(stacktop(-1));\r
-                CBigNum bn;\r
-                switch (opcode)\r
-                {\r
-                case OP_ADD:\r
-                    bn = bn1 + bn2;\r
-                    break;\r
-\r
-                case OP_SUB:\r
-                    bn = bn1 - bn2;\r
-                    break;\r
-\r
-                case OP_MUL:\r
-                    if (!BN_mul(&bn, &bn1, &bn2, pctx))\r
-                        return false;\r
-                    break;\r
-\r
-                case OP_DIV:\r
-                    if (!BN_div(&bn, NULL, &bn1, &bn2, pctx))\r
-                        return false;\r
-                    break;\r
-\r
-                case OP_MOD:\r
-                    if (!BN_mod(&bn, &bn1, &bn2, pctx))\r
-                        return false;\r
-                    break;\r
-\r
-                case OP_LSHIFT:\r
-                    if (bn2 < bnZero)\r
-                        return false;\r
-                    bn = bn1 << bn2.getulong();\r
-                    break;\r
-\r
-                case OP_RSHIFT:\r
-                    if (bn2 < bnZero)\r
-                        return false;\r
-                    bn = bn1 >> bn2.getulong();\r
-                    break;\r
-\r
-                case OP_BOOLAND:             bn = (bn1 != bnZero && bn2 != bnZero); break;\r
-                case OP_BOOLOR:              bn = (bn1 != bnZero || bn2 != bnZero); break;\r
-                case OP_NUMEQUAL:            bn = (bn1 == bn2); break;\r
-                case OP_NUMEQUALVERIFY:      bn = (bn1 == bn2); break;\r
-                case OP_NUMNOTEQUAL:         bn = (bn1 != bn2); break;\r
-                case OP_LESSTHAN:            bn = (bn1 < bn2); break;\r
-                case OP_GREATERTHAN:         bn = (bn1 > bn2); break;\r
-                case OP_LESSTHANOREQUAL:     bn = (bn1 <= bn2); break;\r
-                case OP_GREATERTHANOREQUAL:  bn = (bn1 >= bn2); break;\r
-                case OP_MIN:                 bn = (bn1 < bn2 ? bn1 : bn2); break;\r
-                case OP_MAX:                 bn = (bn1 > bn2 ? bn1 : bn2); break;\r
-                }\r
-                stack.pop_back();\r
-                stack.pop_back();\r
-                stack.push_back(bn.getvch());\r
-\r
-                if (opcode == OP_NUMEQUALVERIFY)\r
-                {\r
-                    if (CastToBool(stacktop(-1)))\r
-                        stack.pop_back();\r
-                    else\r
-                        pc = pend;\r
-                }\r
-            }\r
-            break;\r
-\r
-            case OP_WITHIN:\r
-            {\r
-                // (x min max -- out)\r
-                if (stack.size() < 3)\r
-                    return false;\r
-                CBigNum bn1(stacktop(-3));\r
-                CBigNum bn2(stacktop(-2));\r
-                CBigNum bn3(stacktop(-1));\r
-                bool fValue = (bn2 <= bn1 && bn1 < bn3);\r
-                stack.pop_back();\r
-                stack.pop_back();\r
-                stack.pop_back();\r
-                stack.push_back(fValue ? vchTrue : vchFalse);\r
-            }\r
-            break;\r
-\r
-\r
-            //\r
-            // Crypto\r
-            //\r
-            case OP_RIPEMD160:\r
-            case OP_SHA1:\r
-            case OP_SHA256:\r
-            case OP_HASH160:\r
-            case OP_HASH256:\r
-            {\r
-                // (in -- hash)\r
-                if (stack.size() < 1)\r
-                    return false;\r
-                valtype& vch = stacktop(-1);\r
-                valtype vchHash((opcode == OP_RIPEMD160 || opcode == OP_SHA1 || opcode == OP_HASH160) ? 20 : 32);\r
-                if (opcode == OP_RIPEMD160)\r
-                    RIPEMD160(&vch[0], vch.size(), &vchHash[0]);\r
-                else if (opcode == OP_SHA1)\r
-                    SHA1(&vch[0], vch.size(), &vchHash[0]);\r
-                else if (opcode == OP_SHA256)\r
-                    SHA256(&vch[0], vch.size(), &vchHash[0]);\r
-                else if (opcode == OP_HASH160)\r
-                {\r
-                    uint160 hash160 = Hash160(vch);\r
-                    memcpy(&vchHash[0], &hash160, sizeof(hash160));\r
-                }\r
-                else if (opcode == OP_HASH256)\r
-                {\r
-                    uint256 hash = Hash(vch.begin(), vch.end());\r
-                    memcpy(&vchHash[0], &hash, sizeof(hash));\r
-                }\r
-                stack.pop_back();\r
-                stack.push_back(vchHash);\r
-            }\r
-            break;\r
-\r
-            case OP_CODESEPARATOR:\r
-            {\r
-                // Hash starts after the code separator\r
-                pbegincodehash = pc;\r
-            }\r
-            break;\r
-\r
-            case OP_CHECKSIG:\r
-            case OP_CHECKSIGVERIFY:\r
-            {\r
-                // (sig pubkey -- bool)\r
-                if (stack.size() < 2)\r
-                    return false;\r
-\r
-                valtype& vchSig    = stacktop(-2);\r
-                valtype& vchPubKey = stacktop(-1);\r
-\r
-                ////// debug print\r
-                //PrintHex(vchSig.begin(), vchSig.end(), "sig: %s\n");\r
-                //PrintHex(vchPubKey.begin(), vchPubKey.end(), "pubkey: %s\n");\r
-\r
-                // Subset of script starting at the most recent codeseparator\r
-                CScript scriptCode(pbegincodehash, pend);\r
-\r
-                // Drop the signature, since there's no way for a signature to sign itself\r
-                scriptCode.FindAndDelete(CScript(vchSig));\r
-\r
-                bool fSuccess = CheckSig(vchSig, vchPubKey, scriptCode, txTo, nIn, nHashType);\r
-\r
-                stack.pop_back();\r
-                stack.pop_back();\r
-                stack.push_back(fSuccess ? vchTrue : vchFalse);\r
-                if (opcode == OP_CHECKSIGVERIFY)\r
-                {\r
-                    if (fSuccess)\r
-                        stack.pop_back();\r
-                    else\r
-                        pc = pend;\r
-                }\r
-            }\r
-            break;\r
-\r
-            case OP_CHECKMULTISIG:\r
-            case OP_CHECKMULTISIGVERIFY:\r
-            {\r
-                // ([sig ...] num_of_signatures [pubkey ...] num_of_pubkeys -- bool)\r
-\r
-                int i = 1;\r
-                if (stack.size() < i)\r
-                    return false;\r
-\r
-                int nKeysCount = CBigNum(stacktop(-i)).getint();\r
-                if (nKeysCount < 0)\r
-                    return false;\r
-                int ikey = ++i;\r
-                i += nKeysCount;\r
-                if (stack.size() < i)\r
-                    return false;\r
-\r
-                int nSigsCount = CBigNum(stacktop(-i)).getint();\r
-                if (nSigsCount < 0 || nSigsCount > nKeysCount)\r
-                    return false;\r
-                int isig = ++i;\r
-                i += nSigsCount;\r
-                if (stack.size() < i)\r
-                    return false;\r
-\r
-                // Subset of script starting at the most recent codeseparator\r
-                CScript scriptCode(pbegincodehash, pend);\r
-\r
-                // Drop the signatures, since there's no way for a signature to sign itself\r
-                for (int k = 0; k < nSigsCount; k++)\r
-                {\r
-                    valtype& vchSig = stacktop(-isig-k);\r
-                    scriptCode.FindAndDelete(CScript(vchSig));\r
-                }\r
-\r
-                bool fSuccess = true;\r
-                while (fSuccess && nSigsCount > 0)\r
-                {\r
-                    valtype& vchSig    = stacktop(-isig);\r
-                    valtype& vchPubKey = stacktop(-ikey);\r
-\r
-                    // Check signature\r
-                    if (CheckSig(vchSig, vchPubKey, scriptCode, txTo, nIn, nHashType))\r
-                    {\r
-                        isig++;\r
-                        nSigsCount--;\r
-                    }\r
-                    ikey++;\r
-                    nKeysCount--;\r
-\r
-                    // If there are more signatures left than keys left,\r
-                    // then too many signatures have failed\r
-                    if (nSigsCount > nKeysCount)\r
-                        fSuccess = false;\r
-                }\r
-\r
-                while (i-- > 0)\r
-                    stack.pop_back();\r
-                stack.push_back(fSuccess ? vchTrue : vchFalse);\r
-\r
-                if (opcode == OP_CHECKMULTISIGVERIFY)\r
-                {\r
-                    if (fSuccess)\r
-                        stack.pop_back();\r
-                    else\r
-                        pc = pend;\r
-                }\r
-            }\r
-            break;\r
-\r
-            default:\r
-                return false;\r
-        }\r
-    }\r
-\r
-\r
-    if (pvStackRet)\r
-        *pvStackRet = stack;\r
-    return (stack.empty() ? false : CastToBool(stack.back()));\r
-}\r
-\r
-#undef top\r
-\r
-\r
-\r
-\r
-\r
-\r
-\r
-\r
-\r
-uint256 SignatureHash(CScript scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType)\r
-{\r
-    if (nIn >= txTo.vin.size())\r
-    {\r
-        printf("ERROR: SignatureHash() : nIn=%d out of range\n", nIn);\r
-        return 1;\r
-    }\r
-    CTransaction txTmp(txTo);\r
-\r
-    // In case concatenating two scripts ends up with two codeseparators,\r
-    // or an extra one at the end, this prevents all those possible incompatibilities.\r
-    scriptCode.FindAndDelete(CScript(OP_CODESEPARATOR));\r
-\r
-    // Blank out other inputs' signatures\r
-    for (int i = 0; i < txTmp.vin.size(); i++)\r
-        txTmp.vin[i].scriptSig = CScript();\r
-    txTmp.vin[nIn].scriptSig = scriptCode;\r
-\r
-    // Blank out some of the outputs\r
-    if ((nHashType & 0x1f) == SIGHASH_NONE)\r
-    {\r
-        // Wildcard payee\r
-        txTmp.vout.clear();\r
-\r
-        // Let the others update at will\r
-        for (int i = 0; i < txTmp.vin.size(); i++)\r
-            if (i != nIn)\r
-                txTmp.vin[i].nSequence = 0;\r
-    }\r
-    else if ((nHashType & 0x1f) == SIGHASH_SINGLE)\r
-    {\r
-        // Only lockin the txout payee at same index as txin\r
-        unsigned int nOut = nIn;\r
-        if (nOut >= txTmp.vout.size())\r
-        {\r
-            printf("ERROR: SignatureHash() : nOut=%d out of range\n", nOut);\r
-            return 1;\r
-        }\r
-        txTmp.vout.resize(nOut+1);\r
-        for (int i = 0; i < nOut; i++)\r
-            txTmp.vout[i].SetNull();\r
-\r
-        // Let the others update at will\r
-        for (int i = 0; i < txTmp.vin.size(); i++)\r
-            if (i != nIn)\r
-                txTmp.vin[i].nSequence = 0;\r
-    }\r
-\r
-    // Blank out other inputs completely, not recommended for open transactions\r
-    if (nHashType & SIGHASH_ANYONECANPAY)\r
-    {\r
-        txTmp.vin[0] = txTmp.vin[nIn];\r
-        txTmp.vin.resize(1);\r
-    }\r
-\r
-    // Serialize and hash\r
-    CDataStream ss(SER_GETHASH);\r
-    ss.reserve(10000);\r
-    ss << txTmp << nHashType;\r
-    return Hash(ss.begin(), ss.end());\r
-}\r
-\r
-\r
-bool CheckSig(vector<unsigned char> vchSig, vector<unsigned char> vchPubKey, CScript scriptCode,\r
-              const CTransaction& txTo, unsigned int nIn, int nHashType)\r
-{\r
-    CKey key;\r
-    if (!key.SetPubKey(vchPubKey))\r
-        return false;\r
-\r
-    // Hash type is one byte tacked on to the end of the signature\r
-    if (vchSig.empty())\r
-        return false;\r
-    if (nHashType == 0)\r
-        nHashType = vchSig.back();\r
-    else if (nHashType != vchSig.back())\r
-        return false;\r
-    vchSig.pop_back();\r
-\r
-    if (key.Verify(SignatureHash(scriptCode, txTo, nIn, nHashType), vchSig))\r
-        return true;\r
-\r
-    return false;\r
-}\r
-\r
-\r
-\r
-\r
-\r
-\r
-\r
-\r
-\r
-\r
-bool Solver(const CScript& scriptPubKey, vector<pair<opcodetype, valtype> >& vSolutionRet)\r
-{\r
-    // Templates\r
-    static vector<CScript> vTemplates;\r
-    if (vTemplates.empty())\r
-    {\r
-        // Standard tx, sender provides pubkey, receiver adds signature\r
-        vTemplates.push_back(CScript() << OP_PUBKEY << OP_CHECKSIG);\r
-\r
-        // Bitcoin address tx, sender provides hash of pubkey, receiver provides signature and pubkey\r
-        vTemplates.push_back(CScript() << OP_DUP << OP_HASH160 << OP_PUBKEYHASH << OP_EQUALVERIFY << OP_CHECKSIG);\r
-    }\r
-\r
-    // Scan templates\r
-    const CScript& script1 = scriptPubKey;\r
-    foreach(const CScript& script2, vTemplates)\r
-    {\r
-        vSolutionRet.clear();\r
-        opcodetype opcode1, opcode2;\r
-        vector<unsigned char> vch1, vch2;\r
-\r
-        // Compare\r
-        CScript::const_iterator pc1 = script1.begin();\r
-        CScript::const_iterator pc2 = script2.begin();\r
-        loop\r
-        {\r
-            bool f1 = script1.GetOp(pc1, opcode1, vch1);\r
-            bool f2 = script2.GetOp(pc2, opcode2, vch2);\r
-            if (!f1 && !f2)\r
-            {\r
-                // Success\r
-                reverse(vSolutionRet.begin(), vSolutionRet.end());\r
-                return true;\r
-            }\r
-            else if (f1 != f2)\r
-            {\r
-                break;\r
-            }\r
-            else if (opcode2 == OP_PUBKEY)\r
-            {\r
-                if (vch1.size() <= sizeof(uint256))\r
-                    break;\r
-                vSolutionRet.push_back(make_pair(opcode2, vch1));\r
-            }\r
-            else if (opcode2 == OP_PUBKEYHASH)\r
-            {\r
-                if (vch1.size() != sizeof(uint160))\r
-                    break;\r
-                vSolutionRet.push_back(make_pair(opcode2, vch1));\r
-            }\r
-            else if (opcode1 != opcode2)\r
-            {\r
-                break;\r
-            }\r
-        }\r
-    }\r
-\r
-    vSolutionRet.clear();\r
-    return false;\r
-}\r
-\r
-\r
-bool Solver(const CScript& scriptPubKey, uint256 hash, int nHashType, CScript& scriptSigRet)\r
-{\r
-    scriptSigRet.clear();\r
-\r
-    vector<pair<opcodetype, valtype> > vSolution;\r
-    if (!Solver(scriptPubKey, vSolution))\r
-        return false;\r
-\r
-    // Compile solution\r
-    CRITICAL_BLOCK(cs_mapKeys)\r
-    {\r
-        foreach(PAIRTYPE(opcodetype, valtype)& item, vSolution)\r
-        {\r
-            if (item.first == OP_PUBKEY)\r
-            {\r
-                // Sign\r
-                const valtype& vchPubKey = item.second;\r
-                if (!mapKeys.count(vchPubKey))\r
-                    return false;\r
-                if (hash != 0)\r
-                {\r
-                    vector<unsigned char> vchSig;\r
-                    if (!CKey::Sign(mapKeys[vchPubKey], hash, vchSig))\r
-                        return false;\r
-                    vchSig.push_back((unsigned char)nHashType);\r
-                    scriptSigRet << vchSig;\r
-                }\r
-            }\r
-            else if (item.first == OP_PUBKEYHASH)\r
-            {\r
-                // Sign and give pubkey\r
-                map<uint160, valtype>::iterator mi = mapPubKeys.find(uint160(item.second));\r
-                if (mi == mapPubKeys.end())\r
-                    return false;\r
-                const vector<unsigned char>& vchPubKey = (*mi).second;\r
-                if (!mapKeys.count(vchPubKey))\r
-                    return false;\r
-                if (hash != 0)\r
-                {\r
-                    vector<unsigned char> vchSig;\r
-                    if (!CKey::Sign(mapKeys[vchPubKey], hash, vchSig))\r
-                        return false;\r
-                    vchSig.push_back((unsigned char)nHashType);\r
-                    scriptSigRet << vchSig << vchPubKey;\r
-                }\r
-            }\r
-        }\r
-    }\r
-\r
-    return true;\r
-}\r
-\r
-\r
-bool IsMine(const CScript& scriptPubKey)\r
-{\r
-    CScript scriptSig;\r
-    return Solver(scriptPubKey, 0, 0, scriptSig);\r
-}\r
-\r
-\r
-bool ExtractPubKey(const CScript& scriptPubKey, bool fMineOnly, vector<unsigned char>& vchPubKeyRet)\r
-{\r
-    vchPubKeyRet.clear();\r
-\r
-    vector<pair<opcodetype, valtype> > vSolution;\r
-    if (!Solver(scriptPubKey, vSolution))\r
-        return false;\r
-\r
-    CRITICAL_BLOCK(cs_mapKeys)\r
-    {\r
-        foreach(PAIRTYPE(opcodetype, valtype)& item, vSolution)\r
-        {\r
-            valtype vchPubKey;\r
-            if (item.first == OP_PUBKEY)\r
-            {\r
-                vchPubKey = item.second;\r
-            }\r
-            else if (item.first == OP_PUBKEYHASH)\r
-            {\r
-                map<uint160, valtype>::iterator mi = mapPubKeys.find(uint160(item.second));\r
-                if (mi == mapPubKeys.end())\r
-                    continue;\r
-                vchPubKey = (*mi).second;\r
-            }\r
-            if (!fMineOnly || mapKeys.count(vchPubKey))\r
-            {\r
-                vchPubKeyRet = vchPubKey;\r
-                return true;\r
-            }\r
-        }\r
-    }\r
-    return false;\r
-}\r
-\r
-\r
-bool ExtractHash160(const CScript& scriptPubKey, uint160& hash160Ret)\r
-{\r
-    hash160Ret = 0;\r
-\r
-    vector<pair<opcodetype, valtype> > vSolution;\r
-    if (!Solver(scriptPubKey, vSolution))\r
-        return false;\r
-\r
-    foreach(PAIRTYPE(opcodetype, valtype)& item, vSolution)\r
-    {\r
-        if (item.first == OP_PUBKEYHASH)\r
-        {\r
-            hash160Ret = uint160(item.second);\r
-            return true;\r
-        }\r
-    }\r
-    return false;\r
-}\r
-\r
-\r
-bool SignSignature(const CTransaction& txFrom, CTransaction& txTo, unsigned int nIn, int nHashType, CScript scriptPrereq)\r
-{\r
-    assert(nIn < txTo.vin.size());\r
-    CTxIn& txin = txTo.vin[nIn];\r
-    assert(txin.prevout.n < txFrom.vout.size());\r
-    const CTxOut& txout = txFrom.vout[txin.prevout.n];\r
-\r
-    // Leave out the signature from the hash, since a signature can't sign itself.\r
-    // The checksig op will also drop the signatures from its hash.\r
-    uint256 hash = SignatureHash(scriptPrereq + txout.scriptPubKey, txTo, nIn, nHashType);\r
-\r
-    if (!Solver(txout.scriptPubKey, hash, nHashType, txin.scriptSig))\r
-        return false;\r
-\r
-    txin.scriptSig = scriptPrereq + txin.scriptSig;\r
-\r
-    // Test solution\r
-    if (scriptPrereq.empty())\r
-        if (!EvalScript(txin.scriptSig + CScript(OP_CODESEPARATOR) + txout.scriptPubKey, txTo, nIn))\r
-            return false;\r
-\r
-    return true;\r
-}\r
-\r
-\r
-bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsigned int nIn, int nHashType)\r
-{\r
-    assert(nIn < txTo.vin.size());\r
-    const CTxIn& txin = txTo.vin[nIn];\r
-    if (txin.prevout.n >= txFrom.vout.size())\r
-        return false;\r
-    const CTxOut& txout = txFrom.vout[txin.prevout.n];\r
-\r
-    if (txin.prevout.hash != txFrom.GetHash())\r
-        return false;\r
-\r
-    if (!EvalScript(txin.scriptSig + CScript(OP_CODESEPARATOR) + txout.scriptPubKey, txTo, nIn, nHashType))\r
-        return false;\r
-\r
-    // Anytime a signature is successfully verified, it's proof the outpoint is spent,\r
-    // so lets update the wallet spent flag if it doesn't know due to wallet.dat being\r
-    // restored from backup or the user making copies of wallet.dat.\r
-    WalletUpdateSpent(txin.prevout);\r
-\r
-    return true;\r
-}\r
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Distributed under the MIT/X11 software license, see the accompanying
+// file license.txt or http://www.opensource.org/licenses/mit-license.php.
+
+#include "headers.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 (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();
+}
+
+
+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 >= 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 > vch.size())
+                        nBegin = vch.size();
+                    if (nEnd > 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 > 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 (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 (int i = 0; i < vch1.size(); i++)
+                            vch1[i] &= vch2[i];
+                    }
+                    else if (opcode == OP_OR)
+                    {
+                        for (int i = 0; i < vch1.size(); i++)
+                            vch1[i] |= vch2[i];
+                    }
+                    else if (opcode == OP_XOR)
+                    {
+                        for (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;
+                    }
+                    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;
+                    }
+                    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 (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 (stack.size() < i)
+                        return false;
+
+                    int nSigsCount = CastToBigNum(stacktop(-i)).getint();
+                    if (nSigsCount < 0 || nSigsCount > nKeysCount)
+                        return false;
+                    int isig = ++i;
+                    i += nSigsCount;
+                    if (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 (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 (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 (int i = 0; i < nOut; i++)
+            txTmp.vout[i].SetNull();
+
+        // Let the others update at will
+        for (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);
+    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);
+}
+
+
+
+
+
+
+
+
+
+
+bool Solver(const CScript& scriptPubKey, vector<pair<opcodetype, valtype> >& vSolutionRet)
+{
+    // Templates
+    static vector<CScript> vTemplates;
+    if (vTemplates.empty())
+    {
+        // Standard tx, sender provides pubkey, receiver adds signature
+        vTemplates.push_back(CScript() << OP_PUBKEY << OP_CHECKSIG);
+
+        // Bitcoin address tx, sender provides hash of pubkey, receiver provides signature and pubkey
+        vTemplates.push_back(CScript() << OP_DUP << OP_HASH160 << OP_PUBKEYHASH << OP_EQUALVERIFY << OP_CHECKSIG);
+    }
+
+    // Scan templates
+    const CScript& script1 = scriptPubKey;
+    foreach(const CScript& script2, vTemplates)
+    {
+        vSolutionRet.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
+                reverse(vSolutionRet.begin(), vSolutionRet.end());
+                return true;
+            }
+            if (!script1.GetOp(pc1, opcode1, vch1))
+                break;
+            if (!script2.GetOp(pc2, opcode2, vch2))
+                break;
+            if (opcode2 == OP_PUBKEY)
+            {
+                if (vch1.size() < 33)
+                    break;
+                vSolutionRet.push_back(make_pair(opcode2, vch1));
+            }
+            else if (opcode2 == OP_PUBKEYHASH)
+            {
+                if (vch1.size() != sizeof(uint160))
+                    break;
+                vSolutionRet.push_back(make_pair(opcode2, vch1));
+            }
+            else if (opcode1 != opcode2 || vch1 != vch2)
+            {
+                break;
+            }
+        }
+    }
+
+    vSolutionRet.clear();
+    return false;
+}
+
+
+bool Solver(const CScript& scriptPubKey, uint256 hash, int nHashType, CScript& scriptSigRet)
+{
+    scriptSigRet.clear();
+
+    vector<pair<opcodetype, valtype> > vSolution;
+    if (!Solver(scriptPubKey, vSolution))
+        return false;
+
+    // Compile solution
+    CRITICAL_BLOCK(cs_mapKeys)
+    {
+        foreach(PAIRTYPE(opcodetype, valtype)& item, vSolution)
+        {
+            if (item.first == OP_PUBKEY)
+            {
+                // Sign
+                const valtype& vchPubKey = item.second;
+                if (!mapKeys.count(vchPubKey))
+                    return false;
+                if (hash != 0)
+                {
+                    vector<unsigned char> vchSig;
+                    if (!CKey::Sign(mapKeys[vchPubKey], hash, vchSig))
+                        return false;
+                    vchSig.push_back((unsigned char)nHashType);
+                    scriptSigRet << vchSig;
+                }
+            }
+            else if (item.first == OP_PUBKEYHASH)
+            {
+                // Sign and give pubkey
+                map<uint160, valtype>::iterator mi = mapPubKeys.find(uint160(item.second));
+                if (mi == mapPubKeys.end())
+                    return false;
+                const vector<unsigned char>& vchPubKey = (*mi).second;
+                if (!mapKeys.count(vchPubKey))
+                    return false;
+                if (hash != 0)
+                {
+                    vector<unsigned char> vchSig;
+                    if (!CKey::Sign(mapKeys[vchPubKey], hash, vchSig))
+                        return false;
+                    vchSig.push_back((unsigned char)nHashType);
+                    scriptSigRet << vchSig << vchPubKey;
+                }
+            }
+            else
+            {
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
+
+
+bool IsMine(const CScript& scriptPubKey)
+{
+    CScript scriptSig;
+    return Solver(scriptPubKey, 0, 0, scriptSig);
+}
+
+
+bool ExtractPubKey(const CScript& scriptPubKey, bool fMineOnly, vector<unsigned char>& vchPubKeyRet)
+{
+    vchPubKeyRet.clear();
+
+    vector<pair<opcodetype, valtype> > vSolution;
+    if (!Solver(scriptPubKey, vSolution))
+        return false;
+
+    CRITICAL_BLOCK(cs_mapKeys)
+    {
+        foreach(PAIRTYPE(opcodetype, valtype)& item, vSolution)
+        {
+            valtype vchPubKey;
+            if (item.first == OP_PUBKEY)
+            {
+                vchPubKey = item.second;
+            }
+            else if (item.first == OP_PUBKEYHASH)
+            {
+                map<uint160, valtype>::iterator mi = mapPubKeys.find(uint160(item.second));
+                if (mi == mapPubKeys.end())
+                    continue;
+                vchPubKey = (*mi).second;
+            }
+            if (!fMineOnly || mapKeys.count(vchPubKey))
+            {
+                vchPubKeyRet = vchPubKey;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+
+bool ExtractHash160(const CScript& scriptPubKey, uint160& hash160Ret)
+{
+    hash160Ret = 0;
+
+    vector<pair<opcodetype, valtype> > vSolution;
+    if (!Solver(scriptPubKey, vSolution))
+        return false;
+
+    foreach(PAIRTYPE(opcodetype, valtype)& item, vSolution)
+    {
+        if (item.first == OP_PUBKEYHASH)
+        {
+            hash160Ret = uint160(item.second);
+            return true;
+        }
+    }
+    return false;
+}
+
+
+bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, const CTransaction& txTo, unsigned int nIn, int nHashType)
+{
+    vector<vector<unsigned char> > stack;
+    if (!EvalScript(stack, scriptSig, txTo, nIn, nHashType))
+        return false;
+    if (!EvalScript(stack, scriptPubKey, txTo, nIn, nHashType))
+        return false;
+    if (stack.empty())
+        return false;
+    return CastToBool(stack.back());
+}
+
+
+bool SignSignature(const CTransaction& txFrom, CTransaction& txTo, unsigned int nIn, int nHashType, CScript scriptPrereq)
+{
+    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(scriptPrereq + txout.scriptPubKey, txTo, nIn, nHashType);
+
+    if (!Solver(txout.scriptPubKey, hash, nHashType, txin.scriptSig))
+        return false;
+
+    txin.scriptSig = scriptPrereq + txin.scriptSig;
+
+    // Test solution
+    if (scriptPrereq.empty())
+        if (!VerifyScript(txin.scriptSig, txout.scriptPubKey, txTo, nIn, 0))
+            return false;
+
+    return true;
+}
+
+
+bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsigned int nIn, 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, nHashType))
+        return false;
+
+    // Anytime a signature is successfully verified, it's proof the outpoint is spent,
+    // so lets update the wallet spent flag if it doesn't know due to wallet.dat being
+    // restored from backup or the user making copies of wallet.dat.
+    WalletUpdateSpent(txin.prevout);
+
+    return true;
+}