1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Distributed under the MIT/X11 software license, see the accompanying
3 // file license.txt or http://www.opensource.org/licenses/mit-license.php.
7 bool CheckSig(vector<unsigned char> vchSig, vector<unsigned char> vchPubKey, CScript scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType);
11 typedef vector<unsigned char> valtype;
12 static const valtype vchFalse(0);
13 static const valtype vchZero(0);
14 static const valtype vchTrue(1, 1);
15 static const CBigNum bnZero(0);
16 static const CBigNum bnOne(1);
17 static const CBigNum bnFalse(0);
18 static const CBigNum bnTrue(1);
19 static const size_t nMaxNumSize = 4;
22 CBigNum CastToBigNum(const valtype& vch)
24 if (vch.size() > nMaxNumSize)
25 throw runtime_error("CastToBigNum() : overflow");
26 // Get rid of extra leading zeros
27 return CBigNum(CBigNum(vch).getvch());
30 bool CastToBool(const valtype& vch)
32 for (int i = 0; i < vch.size(); i++)
36 // Can be negative zero
37 if (i == vch.size()-1 && vch[i] == 0x80)
45 void MakeSameSize(valtype& vch1, valtype& vch2)
47 // Lengthen the shorter one
48 if (vch1.size() < vch2.size())
49 vch1.resize(vch2.size(), 0);
50 if (vch2.size() < vch1.size())
51 vch2.resize(vch1.size(), 0);
57 // Script is a stack machine (like Forth) that evaluates a predicate
58 // returning a bool indicating valid or not. There are no loops.
60 #define stacktop(i) (stack.at(stack.size()+(i)))
61 #define altstacktop(i) (altstack.at(altstack.size()+(i)))
62 static inline void popstack(vector<valtype>& stack)
65 throw runtime_error("popstack() : stack empty");
70 bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, const CTransaction& txTo, unsigned int nIn, int nHashType)
73 CScript::const_iterator pc = script.begin();
74 CScript::const_iterator pend = script.end();
75 CScript::const_iterator pbegincodehash = script.begin();
79 vector<valtype> altstack;
80 if (script.size() > 10000)
89 bool fExec = !count(vfExec.begin(), vfExec.end(), false);
94 if (!script.GetOp(pc, opcode, vchPushValue))
96 if (vchPushValue.size() > 520)
98 if (opcode > OP_16 && ++nOpCount > 201)
101 if (opcode == OP_CAT ||
102 opcode == OP_SUBSTR ||
104 opcode == OP_RIGHT ||
105 opcode == OP_INVERT ||
114 opcode == OP_LSHIFT ||
118 if (fExec && 0 <= opcode && opcode <= OP_PUSHDATA4)
119 stack.push_back(vchPushValue);
120 else if (fExec || (OP_IF <= opcode && opcode <= OP_ENDIF))
145 CBigNum bn((int)opcode - (int)(OP_1 - 1));
146 stack.push_back(bn.getvch());
155 case OP_NOP1: case OP_NOP2: case OP_NOP3: case OP_NOP4: case OP_NOP5:
156 case OP_NOP6: case OP_NOP7: case OP_NOP8: case OP_NOP9: case OP_NOP10:
162 // <expression> if [statements] [else [statements]] endif
166 if (stack.size() < 1)
168 valtype& vch = stacktop(-1);
169 fValue = CastToBool(vch);
170 if (opcode == OP_NOTIF)
174 vfExec.push_back(fValue);
182 vfExec.back() = !vfExec.back();
197 // (false -- false) and return
198 if (stack.size() < 1)
200 bool fValue = CastToBool(stacktop(-1));
220 if (stack.size() < 1)
222 altstack.push_back(stacktop(-1));
227 case OP_FROMALTSTACK:
229 if (altstack.size() < 1)
231 stack.push_back(altstacktop(-1));
239 if (stack.size() < 2)
248 // (x1 x2 -- x1 x2 x1 x2)
249 if (stack.size() < 2)
251 valtype vch1 = stacktop(-2);
252 valtype vch2 = stacktop(-1);
253 stack.push_back(vch1);
254 stack.push_back(vch2);
260 // (x1 x2 x3 -- x1 x2 x3 x1 x2 x3)
261 if (stack.size() < 3)
263 valtype vch1 = stacktop(-3);
264 valtype vch2 = stacktop(-2);
265 valtype vch3 = stacktop(-1);
266 stack.push_back(vch1);
267 stack.push_back(vch2);
268 stack.push_back(vch3);
274 // (x1 x2 x3 x4 -- x1 x2 x3 x4 x1 x2)
275 if (stack.size() < 4)
277 valtype vch1 = stacktop(-4);
278 valtype vch2 = stacktop(-3);
279 stack.push_back(vch1);
280 stack.push_back(vch2);
286 // (x1 x2 x3 x4 x5 x6 -- x3 x4 x5 x6 x1 x2)
287 if (stack.size() < 6)
289 valtype vch1 = stacktop(-6);
290 valtype vch2 = stacktop(-5);
291 stack.erase(stack.end()-6, stack.end()-4);
292 stack.push_back(vch1);
293 stack.push_back(vch2);
299 // (x1 x2 x3 x4 -- x3 x4 x1 x2)
300 if (stack.size() < 4)
302 swap(stacktop(-4), stacktop(-2));
303 swap(stacktop(-3), stacktop(-1));
310 if (stack.size() < 1)
312 valtype vch = stacktop(-1);
314 stack.push_back(vch);
321 CBigNum bn(stack.size());
322 stack.push_back(bn.getvch());
329 if (stack.size() < 1)
338 if (stack.size() < 1)
340 valtype vch = stacktop(-1);
341 stack.push_back(vch);
348 if (stack.size() < 2)
350 stack.erase(stack.end() - 2);
356 // (x1 x2 -- x1 x2 x1)
357 if (stack.size() < 2)
359 valtype vch = stacktop(-2);
360 stack.push_back(vch);
367 // (xn ... x2 x1 x0 n - xn ... x2 x1 x0 xn)
368 // (xn ... x2 x1 x0 n - ... x2 x1 x0 xn)
369 if (stack.size() < 2)
371 int n = CastToBigNum(stacktop(-1)).getint();
373 if (n < 0 || n >= stack.size())
375 valtype vch = stacktop(-n-1);
376 if (opcode == OP_ROLL)
377 stack.erase(stack.end()-n-1);
378 stack.push_back(vch);
384 // (x1 x2 x3 -- x2 x3 x1)
385 // x2 x1 x3 after first swap
386 // x2 x3 x1 after second swap
387 if (stack.size() < 3)
389 swap(stacktop(-3), stacktop(-2));
390 swap(stacktop(-2), stacktop(-1));
397 if (stack.size() < 2)
399 swap(stacktop(-2), stacktop(-1));
405 // (x1 x2 -- x2 x1 x2)
406 if (stack.size() < 2)
408 valtype vch = stacktop(-1);
409 stack.insert(stack.end()-2, vch);
420 if (stack.size() < 2)
422 valtype& vch1 = stacktop(-2);
423 valtype& vch2 = stacktop(-1);
424 vch1.insert(vch1.end(), vch2.begin(), vch2.end());
426 if (stacktop(-1).size() > 520)
433 // (in begin size -- out)
434 if (stack.size() < 3)
436 valtype& vch = stacktop(-3);
437 int nBegin = CastToBigNum(stacktop(-2)).getint();
438 int nEnd = nBegin + CastToBigNum(stacktop(-1)).getint();
439 if (nBegin < 0 || nEnd < nBegin)
441 if (nBegin > vch.size())
443 if (nEnd > vch.size())
445 vch.erase(vch.begin() + nEnd, vch.end());
446 vch.erase(vch.begin(), vch.begin() + nBegin);
456 if (stack.size() < 2)
458 valtype& vch = stacktop(-2);
459 int nSize = CastToBigNum(stacktop(-1)).getint();
462 if (nSize > vch.size())
464 if (opcode == OP_LEFT)
465 vch.erase(vch.begin() + nSize, vch.end());
467 vch.erase(vch.begin(), vch.end() - nSize);
475 if (stack.size() < 1)
477 CBigNum bn(stacktop(-1).size());
478 stack.push_back(bn.getvch());
489 if (stack.size() < 1)
491 valtype& vch = stacktop(-1);
492 for (int i = 0; i < vch.size(); i++)
502 if (stack.size() < 2)
504 valtype& vch1 = stacktop(-2);
505 valtype& vch2 = stacktop(-1);
506 MakeSameSize(vch1, vch2);
507 if (opcode == OP_AND)
509 for (int i = 0; i < vch1.size(); i++)
512 else if (opcode == OP_OR)
514 for (int i = 0; i < vch1.size(); i++)
517 else if (opcode == OP_XOR)
519 for (int i = 0; i < vch1.size(); i++)
528 //case OP_NOTEQUAL: // use OP_NUMNOTEQUAL
531 if (stack.size() < 2)
533 valtype& vch1 = stacktop(-2);
534 valtype& vch2 = stacktop(-1);
535 bool fEqual = (vch1 == vch2);
536 // OP_NOTEQUAL is disabled because it would be too easy to say
537 // something like n != 1 and have some wiseguy pass in 1 with extra
538 // zero bytes after it (numerically, 0x01 == 0x0001 == 0x000001)
539 //if (opcode == OP_NOTEQUAL)
543 stack.push_back(fEqual ? vchTrue : vchFalse);
544 if (opcode == OP_EQUALVERIFY)
568 if (stack.size() < 1)
570 CBigNum bn = CastToBigNum(stacktop(-1));
573 case OP_1ADD: bn += bnOne; break;
574 case OP_1SUB: bn -= bnOne; break;
575 case OP_2MUL: bn <<= 1; break;
576 case OP_2DIV: bn >>= 1; break;
577 case OP_NEGATE: bn = -bn; break;
578 case OP_ABS: if (bn < bnZero) bn = -bn; break;
579 case OP_NOT: bn = (bn == bnZero); break;
580 case OP_0NOTEQUAL: bn = (bn != bnZero); break;
583 stack.push_back(bn.getvch());
597 case OP_NUMEQUALVERIFY:
601 case OP_LESSTHANOREQUAL:
602 case OP_GREATERTHANOREQUAL:
607 if (stack.size() < 2)
609 CBigNum bn1 = CastToBigNum(stacktop(-2));
610 CBigNum bn2 = CastToBigNum(stacktop(-1));
623 if (!BN_mul(&bn, &bn1, &bn2, pctx))
628 if (!BN_div(&bn, NULL, &bn1, &bn2, pctx))
633 if (!BN_mod(&bn, &bn1, &bn2, pctx))
638 if (bn2 < bnZero || bn2 > CBigNum(2048))
640 bn = bn1 << bn2.getulong();
644 if (bn2 < bnZero || bn2 > CBigNum(2048))
646 bn = bn1 >> bn2.getulong();
649 case OP_BOOLAND: bn = (bn1 != bnZero && bn2 != bnZero); break;
650 case OP_BOOLOR: bn = (bn1 != bnZero || bn2 != bnZero); break;
651 case OP_NUMEQUAL: bn = (bn1 == bn2); break;
652 case OP_NUMEQUALVERIFY: bn = (bn1 == bn2); break;
653 case OP_NUMNOTEQUAL: bn = (bn1 != bn2); break;
654 case OP_LESSTHAN: bn = (bn1 < bn2); break;
655 case OP_GREATERTHAN: bn = (bn1 > bn2); break;
656 case OP_LESSTHANOREQUAL: bn = (bn1 <= bn2); break;
657 case OP_GREATERTHANOREQUAL: bn = (bn1 >= bn2); break;
658 case OP_MIN: bn = (bn1 < bn2 ? bn1 : bn2); break;
659 case OP_MAX: bn = (bn1 > bn2 ? bn1 : bn2); break;
663 stack.push_back(bn.getvch());
665 if (opcode == OP_NUMEQUALVERIFY)
667 if (CastToBool(stacktop(-1)))
677 // (x min max -- out)
678 if (stack.size() < 3)
680 CBigNum bn1 = CastToBigNum(stacktop(-3));
681 CBigNum bn2 = CastToBigNum(stacktop(-2));
682 CBigNum bn3 = CastToBigNum(stacktop(-1));
683 bool fValue = (bn2 <= bn1 && bn1 < bn3);
687 stack.push_back(fValue ? vchTrue : vchFalse);
702 if (stack.size() < 1)
704 valtype& vch = stacktop(-1);
705 valtype vchHash((opcode == OP_RIPEMD160 || opcode == OP_SHA1 || opcode == OP_HASH160) ? 20 : 32);
706 if (opcode == OP_RIPEMD160)
707 RIPEMD160(&vch[0], vch.size(), &vchHash[0]);
708 else if (opcode == OP_SHA1)
709 SHA1(&vch[0], vch.size(), &vchHash[0]);
710 else if (opcode == OP_SHA256)
711 SHA256(&vch[0], vch.size(), &vchHash[0]);
712 else if (opcode == OP_HASH160)
714 uint160 hash160 = Hash160(vch);
715 memcpy(&vchHash[0], &hash160, sizeof(hash160));
717 else if (opcode == OP_HASH256)
719 uint256 hash = Hash(vch.begin(), vch.end());
720 memcpy(&vchHash[0], &hash, sizeof(hash));
723 stack.push_back(vchHash);
727 case OP_CODESEPARATOR:
729 // Hash starts after the code separator
735 case OP_CHECKSIGVERIFY:
737 // (sig pubkey -- bool)
738 if (stack.size() < 2)
741 valtype& vchSig = stacktop(-2);
742 valtype& vchPubKey = stacktop(-1);
745 //PrintHex(vchSig.begin(), vchSig.end(), "sig: %s\n");
746 //PrintHex(vchPubKey.begin(), vchPubKey.end(), "pubkey: %s\n");
748 // Subset of script starting at the most recent codeseparator
749 CScript scriptCode(pbegincodehash, pend);
751 // Drop the signature, since there's no way for a signature to sign itself
752 scriptCode.FindAndDelete(CScript(vchSig));
754 bool fSuccess = CheckSig(vchSig, vchPubKey, scriptCode, txTo, nIn, nHashType);
758 stack.push_back(fSuccess ? vchTrue : vchFalse);
759 if (opcode == OP_CHECKSIGVERIFY)
769 case OP_CHECKMULTISIG:
770 case OP_CHECKMULTISIGVERIFY:
772 // ([sig ...] num_of_signatures [pubkey ...] num_of_pubkeys -- bool)
775 if (stack.size() < i)
778 int nKeysCount = CastToBigNum(stacktop(-i)).getint();
779 if (nKeysCount < 0 || nKeysCount > 20)
781 nOpCount += nKeysCount;
786 if (stack.size() < i)
789 int nSigsCount = CastToBigNum(stacktop(-i)).getint();
790 if (nSigsCount < 0 || nSigsCount > nKeysCount)
794 if (stack.size() < i)
797 // Subset of script starting at the most recent codeseparator
798 CScript scriptCode(pbegincodehash, pend);
800 // Drop the signatures, since there's no way for a signature to sign itself
801 for (int k = 0; k < nSigsCount; k++)
803 valtype& vchSig = stacktop(-isig-k);
804 scriptCode.FindAndDelete(CScript(vchSig));
807 bool fSuccess = true;
808 while (fSuccess && nSigsCount > 0)
810 valtype& vchSig = stacktop(-isig);
811 valtype& vchPubKey = stacktop(-ikey);
814 if (CheckSig(vchSig, vchPubKey, scriptCode, txTo, nIn, nHashType))
822 // If there are more signatures left than keys left,
823 // then too many signatures have failed
824 if (nSigsCount > nKeysCount)
830 stack.push_back(fSuccess ? vchTrue : vchFalse);
832 if (opcode == OP_CHECKMULTISIGVERIFY)
847 if (stack.size() + altstack.size() > 1000)
871 uint256 SignatureHash(CScript scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType)
873 if (nIn >= txTo.vin.size())
875 printf("ERROR: SignatureHash() : nIn=%d out of range\n", nIn);
878 CTransaction txTmp(txTo);
880 // In case concatenating two scripts ends up with two codeseparators,
881 // or an extra one at the end, this prevents all those possible incompatibilities.
882 scriptCode.FindAndDelete(CScript(OP_CODESEPARATOR));
884 // Blank out other inputs' signatures
885 for (int i = 0; i < txTmp.vin.size(); i++)
886 txTmp.vin[i].scriptSig = CScript();
887 txTmp.vin[nIn].scriptSig = scriptCode;
889 // Blank out some of the outputs
890 if ((nHashType & 0x1f) == SIGHASH_NONE)
895 // Let the others update at will
896 for (int i = 0; i < txTmp.vin.size(); i++)
898 txTmp.vin[i].nSequence = 0;
900 else if ((nHashType & 0x1f) == SIGHASH_SINGLE)
902 // Only lockin the txout payee at same index as txin
903 unsigned int nOut = nIn;
904 if (nOut >= txTmp.vout.size())
906 printf("ERROR: SignatureHash() : nOut=%d out of range\n", nOut);
909 txTmp.vout.resize(nOut+1);
910 for (int i = 0; i < nOut; i++)
911 txTmp.vout[i].SetNull();
913 // Let the others update at will
914 for (int i = 0; i < txTmp.vin.size(); i++)
916 txTmp.vin[i].nSequence = 0;
919 // Blank out other inputs completely, not recommended for open transactions
920 if (nHashType & SIGHASH_ANYONECANPAY)
922 txTmp.vin[0] = txTmp.vin[nIn];
926 // Serialize and hash
927 CDataStream ss(SER_GETHASH);
929 ss << txTmp << nHashType;
930 return Hash(ss.begin(), ss.end());
934 bool CheckSig(vector<unsigned char> vchSig, vector<unsigned char> vchPubKey, CScript scriptCode,
935 const CTransaction& txTo, unsigned int nIn, int nHashType)
938 if (!key.SetPubKey(vchPubKey))
941 // Hash type is one byte tacked on to the end of the signature
945 nHashType = vchSig.back();
946 else if (nHashType != vchSig.back())
950 return key.Verify(SignatureHash(scriptCode, txTo, nIn, nHashType), vchSig);
962 bool Solver(const CScript& scriptPubKey, vector<pair<opcodetype, valtype> >& vSolutionRet)
965 static vector<CScript> vTemplates;
966 if (vTemplates.empty())
968 // Standard tx, sender provides pubkey, receiver adds signature
969 vTemplates.push_back(CScript() << OP_PUBKEY << OP_CHECKSIG);
971 // Bitcoin address tx, sender provides hash of pubkey, receiver provides signature and pubkey
972 vTemplates.push_back(CScript() << OP_DUP << OP_HASH160 << OP_PUBKEYHASH << OP_EQUALVERIFY << OP_CHECKSIG);
976 const CScript& script1 = scriptPubKey;
977 foreach(const CScript& script2, vTemplates)
979 vSolutionRet.clear();
980 opcodetype opcode1, opcode2;
981 vector<unsigned char> vch1, vch2;
984 CScript::const_iterator pc1 = script1.begin();
985 CScript::const_iterator pc2 = script2.begin();
988 if (pc1 == script1.end() && pc2 == script2.end())
991 reverse(vSolutionRet.begin(), vSolutionRet.end());
994 if (!script1.GetOp(pc1, opcode1, vch1))
996 if (!script2.GetOp(pc2, opcode2, vch2))
998 if (opcode2 == OP_PUBKEY)
1000 if (vch1.size() < 33 || vch1.size() > 120)
1002 vSolutionRet.push_back(make_pair(opcode2, vch1));
1004 else if (opcode2 == OP_PUBKEYHASH)
1006 if (vch1.size() != sizeof(uint160))
1008 vSolutionRet.push_back(make_pair(opcode2, vch1));
1010 else if (opcode1 != opcode2 || vch1 != vch2)
1017 vSolutionRet.clear();
1022 bool Solver(const CScript& scriptPubKey, uint256 hash, int nHashType, CScript& scriptSigRet)
1024 scriptSigRet.clear();
1026 vector<pair<opcodetype, valtype> > vSolution;
1027 if (!Solver(scriptPubKey, vSolution))
1031 CRITICAL_BLOCK(cs_mapKeys)
1033 foreach(PAIRTYPE(opcodetype, valtype)& item, vSolution)
1035 if (item.first == OP_PUBKEY)
1038 const valtype& vchPubKey = item.second;
1039 if (!mapKeys.count(vchPubKey))
1043 vector<unsigned char> vchSig;
1044 if (!CKey::Sign(mapKeys[vchPubKey], hash, vchSig))
1046 vchSig.push_back((unsigned char)nHashType);
1047 scriptSigRet << vchSig;
1050 else if (item.first == OP_PUBKEYHASH)
1052 // Sign and give pubkey
1053 map<uint160, valtype>::iterator mi = mapPubKeys.find(uint160(item.second));
1054 if (mi == mapPubKeys.end())
1056 const vector<unsigned char>& vchPubKey = (*mi).second;
1057 if (!mapKeys.count(vchPubKey))
1061 vector<unsigned char> vchSig;
1062 if (!CKey::Sign(mapKeys[vchPubKey], hash, vchSig))
1064 vchSig.push_back((unsigned char)nHashType);
1065 scriptSigRet << vchSig << vchPubKey;
1079 bool IsStandard(const CScript& scriptPubKey)
1081 vector<pair<opcodetype, valtype> > vSolution;
1082 return Solver(scriptPubKey, vSolution);
1086 bool IsMine(const CScript& scriptPubKey)
1089 return Solver(scriptPubKey, 0, 0, scriptSig);
1093 bool ExtractPubKey(const CScript& scriptPubKey, bool fMineOnly, vector<unsigned char>& vchPubKeyRet)
1095 vchPubKeyRet.clear();
1097 vector<pair<opcodetype, valtype> > vSolution;
1098 if (!Solver(scriptPubKey, vSolution))
1101 CRITICAL_BLOCK(cs_mapKeys)
1103 foreach(PAIRTYPE(opcodetype, valtype)& item, vSolution)
1106 if (item.first == OP_PUBKEY)
1108 vchPubKey = item.second;
1110 else if (item.first == OP_PUBKEYHASH)
1112 map<uint160, valtype>::iterator mi = mapPubKeys.find(uint160(item.second));
1113 if (mi == mapPubKeys.end())
1115 vchPubKey = (*mi).second;
1117 if (!fMineOnly || mapKeys.count(vchPubKey))
1119 vchPubKeyRet = vchPubKey;
1128 bool ExtractHash160(const CScript& scriptPubKey, uint160& hash160Ret)
1132 vector<pair<opcodetype, valtype> > vSolution;
1133 if (!Solver(scriptPubKey, vSolution))
1136 foreach(PAIRTYPE(opcodetype, valtype)& item, vSolution)
1138 if (item.first == OP_PUBKEYHASH)
1140 hash160Ret = uint160(item.second);
1148 bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, const CTransaction& txTo, unsigned int nIn, int nHashType)
1150 vector<vector<unsigned char> > stack;
1151 if (!EvalScript(stack, scriptSig, txTo, nIn, nHashType))
1153 if (!EvalScript(stack, scriptPubKey, txTo, nIn, nHashType))
1157 return CastToBool(stack.back());
1161 bool SignSignature(const CTransaction& txFrom, CTransaction& txTo, unsigned int nIn, int nHashType, CScript scriptPrereq)
1163 assert(nIn < txTo.vin.size());
1164 CTxIn& txin = txTo.vin[nIn];
1165 assert(txin.prevout.n < txFrom.vout.size());
1166 const CTxOut& txout = txFrom.vout[txin.prevout.n];
1168 // Leave out the signature from the hash, since a signature can't sign itself.
1169 // The checksig op will also drop the signatures from its hash.
1170 uint256 hash = SignatureHash(scriptPrereq + txout.scriptPubKey, txTo, nIn, nHashType);
1172 if (!Solver(txout.scriptPubKey, hash, nHashType, txin.scriptSig))
1175 txin.scriptSig = scriptPrereq + txin.scriptSig;
1178 if (scriptPrereq.empty())
1179 if (!VerifyScript(txin.scriptSig, txout.scriptPubKey, txTo, nIn, 0))
1186 bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsigned int nIn, int nHashType)
1188 assert(nIn < txTo.vin.size());
1189 const CTxIn& txin = txTo.vin[nIn];
1190 if (txin.prevout.n >= txFrom.vout.size())
1192 const CTxOut& txout = txFrom.vout[txin.prevout.n];
1194 if (txin.prevout.hash != txFrom.GetHash())
1197 if (!VerifyScript(txin.scriptSig, txout.scriptPubKey, txTo, nIn, nHashType))
1200 // Anytime a signature is successfully verified, it's proof the outpoint is spent,
1201 // so lets update the wallet spent flag if it doesn't know due to wallet.dat being
1202 // restored from backup or the user making copies of wallet.dat.
1203 WalletUpdateSpent(txin.prevout);