1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2012 The Bitcoin developers
3 // Distributed under the MIT/X11 software license, see the accompanying
4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
5 #ifndef H_BITCOIN_SCRIPT
6 #define H_BITCOIN_SCRIPT
11 #include <boost/foreach.hpp>
16 typedef std::vector<uint8_t> valtype;
20 static const unsigned int MAX_SCRIPT_ELEMENT_SIZE = 520; // bytes
22 /* Setting nSequence to this value for every input in a transaction
23 * disables nLockTime. */
24 static const uint32_t SEQUENCE_FINAL = 0xffffffff;
26 /* Threshold for inverted nSequence: below this value it is interpreted
27 * as a relative lock-time, otherwise ignored. */
28 static const uint32_t SEQUENCE_THRESHOLD = (1 << 31);
30 /* If this flag set, CTxIn::nSequence is NOT interpreted as a
31 * relative lock-time. */
32 static const uint32_t SEQUENCE_LOCKTIME_DISABLE_FLAG = (1 << 31);
34 /* If CTxIn::nSequence encodes a relative lock-time and this flag
35 * is set, the relative lock-time has units of 512 seconds,
36 * otherwise it specifies blocks with a granularity of 1. */
37 static const uint32_t SEQUENCE_LOCKTIME_TYPE_FLAG = (1 << 22);
39 /* If CTxIn::nSequence encodes a relative lock-time, this mask is
40 * applied to extract that lock-time from the sequence field. */
41 static const uint32_t SEQUENCE_LOCKTIME_MASK = 0x0000ffff;
43 /** IsMine() return codes */
49 MINE_ALL = MINE_WATCH_ONLY | MINE_SPENDABLE
52 typedef uint8_t isminefilter;
54 /** Signature hash types/flags */
60 SIGHASH_ANYONECANPAY = 0x80
63 /** Script verification flags */
66 SCRIPT_VERIFY_NONE = 0,
67 SCRIPT_VERIFY_P2SH = (1U << 0), // evaluate P2SH (BIP16) subscripts
68 SCRIPT_VERIFY_STRICTENC = (1U << 1), // enforce strict conformance to DER and SEC2 for signatures and pubkeys
69 SCRIPT_VERIFY_LOW_S = (1U << 2), // enforce low S values in signatures (depends on STRICTENC)
70 SCRIPT_VERIFY_NOCACHE = (1U << 3), // do not store results in signature cache (but do query it)
71 SCRIPT_VERIFY_NULLDUMMY = (1U << 4), // verify dummy stack item consumed by CHECKMULTISIG is of zero-length
72 SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY = (1U << 9),
73 SCRIPT_VERIFY_CHECKSEQUENCEVERIFY = (1U << 10)
76 // Strict verification:
78 // * force DER encoding;
80 // * ensure that CHECKMULTISIG dummy argument is null.
81 static const unsigned int STRICT_FORMAT_FLAGS = SCRIPT_VERIFY_STRICTENC | SCRIPT_VERIFY_LOW_S | SCRIPT_VERIFY_NULLDUMMY;
83 // Mandatory script verification flags that all new blocks must comply with for
84 // them to be valid. (but old blocks may not comply with) Currently just P2SH,
85 // but in the future other flags may be added, such as a soft-fork to enforce
86 // strict DER encoding.
88 // Failing one of these tests may trigger a DoS ban - see ConnectInputs() for
90 static const unsigned int MANDATORY_SCRIPT_VERIFY_FLAGS = SCRIPT_VERIFY_P2SH;
92 // Standard script verification flags that standard transactions will comply
93 // with. However scripts violating these flags may still be present in valid
94 // blocks and we must accept those blocks.
95 static const unsigned int STRICT_FLAGS = MANDATORY_SCRIPT_VERIFY_FLAGS | STRICT_FORMAT_FLAGS;
100 // 'standard' transaction types:
109 const char* GetTxnOutputType(txnouttype t);
111 /** Script opcodes */
151 OP_CHECKLOCKTIMEVERIFY = 0xb1,
152 OP_CHECKSEQUENCEVERIFY = 0xb2,
155 OP_TOALTSTACK = 0x6b,
156 OP_FROMALTSTACK = 0x6c,
188 OP_EQUALVERIFY = 0x88,
213 OP_NUMEQUALVERIFY = 0x9d,
214 OP_NUMNOTEQUAL = 0x9e,
216 OP_GREATERTHAN = 0xa0,
217 OP_LESSTHANOREQUAL = 0xa1,
218 OP_GREATERTHANOREQUAL = 0xa2,
230 OP_CODESEPARATOR = 0xab,
232 OP_CHECKSIGVERIFY = 0xad,
233 OP_CHECKMULTISIG = 0xae,
234 OP_CHECKMULTISIGVERIFY = 0xaf,
246 // template matching params
248 OP_SMALLINTEGER = 0xfa,
251 OP_PUBKEYHASH = 0xfd,
254 OP_INVALIDOPCODE = 0xff
257 const char* GetOpName(opcodetype opcode);
259 inline std::string ValueString(const std::vector<unsigned char>& vch)
262 return strprintf("%d", CBigNum(vch).getint32());
267 inline std::string StackString(const std::vector<std::vector<unsigned char> >& vStack)
270 BOOST_FOREACH(const std::vector<unsigned char>& vch, vStack)
274 str += ValueString(vch);
279 /** Serialized script, used inside transaction inputs and outputs */
280 class CScript : public std::vector<uint8_t>
283 CScript& push_int64(int64_t n)
285 if (n == -1 || (n >= 1 && n <= 16))
287 push_back((uint8_t)n + (OP_1 - 1));
292 *this << bn.getvch();
297 CScript& push_uint64(uint64_t n)
299 if (n >= 1 && n <= 16)
301 push_back((uint8_t)n + (OP_1 - 1));
306 *this << bn.getvch();
313 CScript(const CScript& b) : std::vector<uint8_t>(b.begin(), b.end()) { }
314 CScript(const_iterator pbegin, const_iterator pend) : std::vector<uint8_t>(pbegin, pend) { }
316 CScript(const uint8_t* pbegin, const uint8_t* pend) : std::vector<uint8_t>(pbegin, pend) { }
319 CScript& operator+=(const CScript& b)
321 insert(end(), b.begin(), b.end());
325 friend CScript operator+(const CScript& a, const CScript& b)
332 explicit CScript(int8_t b) { operator<<(b); }
333 explicit CScript(int16_t b) { operator<<(b); }
334 explicit CScript(int32_t b) { operator<<(b); }
335 explicit CScript(int64_t b) { operator<<(b); }
337 explicit CScript(uint8_t b) { operator<<(b); }
338 explicit CScript(uint16_t b) { operator<<(b); }
339 explicit CScript(uint32_t b) { operator<<(b); }
340 explicit CScript(uint64_t b) { operator<<(b); }
342 explicit CScript(opcodetype b) { operator<<(b); }
343 explicit CScript(const uint256& b) { operator<<(b); }
344 explicit CScript(const CBigNum& b) { operator<<(b); }
345 explicit CScript(const std::vector<uint8_t>& b) { operator<<(b); }
347 CScript& operator<<(int8_t b) { return push_int64(b); }
348 CScript& operator<<(int16_t b) { return push_int64(b); }
349 CScript& operator<<(int32_t b) { return push_int64(b); }
350 CScript& operator<<(int64_t b) { return push_int64(b); }
352 CScript& operator<<(uint8_t b) { return push_uint64(b); }
353 CScript& operator<<(uint16_t b) { return push_uint64(b); }
354 CScript& operator<<(uint32_t b) { return push_uint64(b); }
355 CScript& operator<<(uint64_t b) { return push_uint64(b); }
357 CScript& operator<<(opcodetype opcode)
359 if (opcode < 0 || opcode > 0xff)
360 throw std::runtime_error("CScript::operator<<() : invalid opcode");
361 insert(end(), (uint8_t)opcode);
365 CScript& operator<<(const uint160& b)
367 insert(end(), sizeof(b));
368 insert(end(), (uint8_t*)&b, (uint8_t*)&b + sizeof(b));
372 CScript& operator<<(const uint256& b)
374 insert(end(), sizeof(b));
375 insert(end(), (uint8_t*)&b, (uint8_t*)&b + sizeof(b));
379 CScript& operator<<(const CPubKey& key)
381 std::vector<uint8_t> vchKey = key.Raw();
382 return (*this) << vchKey;
385 CScript& operator<<(const CBigNum& b)
391 CScript& operator<<(const std::vector<uint8_t>& b)
393 if (b.size() < OP_PUSHDATA1)
395 insert(end(), (uint8_t)b.size());
397 else if (b.size() <= 0xff)
399 insert(end(), OP_PUSHDATA1);
400 insert(end(), (uint8_t)b.size());
402 else if (b.size() <= 0xffff)
404 insert(end(), OP_PUSHDATA2);
405 uint16_t nSize = (uint16_t) b.size();
406 insert(end(), (uint8_t*)&nSize, (uint8_t*)&nSize + sizeof(nSize));
410 insert(end(), OP_PUSHDATA4);
411 uint32_t nSize = (uint32_t) b.size();
412 insert(end(), (uint8_t*)&nSize, (uint8_t*)&nSize + sizeof(nSize));
414 insert(end(), b.begin(), b.end());
418 CScript& operator<<(const CScript& b)
420 // I'm not sure if this should push the script or concatenate scripts.
421 // If there's ever a use for pushing a script onto a script, delete this member fn
422 assert(!"Warning: Pushing a CScript onto a CScript with << is probably not intended, use + to concatenate!");
427 bool GetOp(iterator& pc, opcodetype& opcodeRet, std::vector<uint8_t>& vchRet)
429 // Wrapper so it can be called with either iterator or const_iterator
430 const_iterator pc2 = pc;
431 bool fRet = GetOp2(pc2, opcodeRet, &vchRet);
432 pc = begin() + (pc2 - begin());
436 bool GetOp(iterator& pc, opcodetype& opcodeRet)
438 const_iterator pc2 = pc;
439 bool fRet = GetOp2(pc2, opcodeRet, NULL);
440 pc = begin() + (pc2 - begin());
444 bool GetOp(const_iterator& pc, opcodetype& opcodeRet, std::vector<uint8_t>& vchRet) const
446 return GetOp2(pc, opcodeRet, &vchRet);
449 bool GetOp(const_iterator& pc, opcodetype& opcodeRet) const
451 return GetOp2(pc, opcodeRet, NULL);
454 bool GetOp2(const_iterator& pc, opcodetype& opcodeRet, std::vector<uint8_t>* pvchRet) const
456 opcodeRet = OP_INVALIDOPCODE;
465 uint32_t opcode = *pc++;
468 if (opcode <= OP_PUSHDATA4)
470 uint32_t nSize = OP_0;
471 if (opcode < OP_PUSHDATA1)
475 else if (opcode == OP_PUSHDATA1)
481 else if (opcode == OP_PUSHDATA2)
485 memcpy(&nSize, &pc[0], 2);
488 else if (opcode == OP_PUSHDATA4)
492 memcpy(&nSize, &pc[0], 4);
495 if (end() - pc < 0 || (uint32_t)(end() - pc) < nSize)
498 pvchRet->assign(pc, pc + nSize);
502 opcodeRet = (opcodetype)opcode;
506 // Encode/decode small integers:
507 static int DecodeOP_N(opcodetype opcode)
511 assert(opcode >= OP_1 && opcode <= OP_16);
512 return (opcode - (OP_1 - 1));
514 static opcodetype EncodeOP_N(int n)
516 assert(n >= 0 && n <= 16);
519 return (opcodetype)(OP_1+n-1);
522 int FindAndDelete(const CScript& b)
527 iterator pc = begin();
531 while (end() - pc >= (long)b.size() && memcmp(&pc[0], &b[0], b.size()) == 0)
533 erase(pc, pc + b.size());
537 while (GetOp(pc, opcode));
540 int Find(opcodetype op) const
544 for (const_iterator pc = begin(); pc != end() && GetOp(pc, opcode);)
550 // Pre-version-0.6, Bitcoin always counted CHECKMULTISIGs
551 // as 20 sigops. With pay-to-script-hash, that changed:
552 // CHECKMULTISIGs serialized in scriptSigs are
553 // counted more accurately, assuming they are of the form
554 // ... OP_N CHECKMULTISIG ...
555 unsigned int GetSigOpCount(bool fAccurate) const;
557 // Accurately count sigOps, including sigOps in
558 // pay-to-script-hash transactions:
559 unsigned int GetSigOpCount(const CScript& scriptSig) const;
561 bool IsPayToScriptHash() const;
563 bool IsPushOnly(const_iterator pc) const
568 if (!GetOp(pc, opcode))
576 // Called by CTransaction::IsStandard and P2SH VerifyScript (which makes it consensus-critical).
577 bool IsPushOnly() const
579 return this->IsPushOnly(begin());
582 // Called by CTransaction::IsStandard.
583 bool HasCanonicalPushes() const;
585 void SetDestination(const CTxDestination& address);
586 void SetDestination(const CPubKey& R, CPubKey& pubKeyVariant);
587 void SetMultisig(int nRequired, const std::vector<CKey>& keys);
590 void PrintHex() const
592 printf("CScript(%s)\n", HexStr(begin(), end(), true).c_str());
595 std::string ToString(bool fShort=false) const
599 std::vector<uint8_t> vch;
600 const_iterator pc = begin();
605 if (!GetOp(pc, opcode, vch))
610 if (0 <= opcode && opcode <= OP_PUSHDATA4)
611 str += fShort? ValueString(vch).substr(0, 10) : ValueString(vch);
613 str += GetOpName(opcode);
620 printf("%s\n", ToString().c_str());
623 CScriptID GetID() const
625 return CScriptID(Hash160(*this));
629 bool IsCanonicalPubKey(const std::vector<unsigned char> &vchPubKey, unsigned int flags);
630 bool IsDERSignature(const valtype &vchSig, bool fWithHashType=false, bool fCheckLow=false);
631 bool IsCanonicalSignature(const std::vector<unsigned char> &vchSig, unsigned int flags);
633 bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript& script, const CTransaction& txTo, unsigned int nIn, unsigned int flags, int nHashType);
634 bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<std::vector<unsigned char> >& vSolutionsRet);
635 int ScriptSigArgsExpected(txnouttype t, const std::vector<std::vector<unsigned char> >& vSolutions);
636 bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType);
637 isminetype IsMine(const CKeyStore& keystore, const CScript& scriptPubKey);
638 isminetype IsMine(const CKeyStore& keystore, const CTxDestination& dest);
639 void ExtractAffectedKeys(const CKeyStore &keystore, const CScript& scriptPubKey, std::vector<CKeyID> &vKeys);
640 bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet);
641 bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet);
642 bool SignSignature(const CKeyStore& keystore, const CScript& fromPubKey, CTransaction& txTo, unsigned int nIn, int nHashType=SIGHASH_ALL);
643 bool SignSignature(const CKeyStore& keystore, const CTransaction& txFrom, CTransaction& txTo, unsigned int nIn, int nHashType=SIGHASH_ALL);
644 bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, const CTransaction& txTo, unsigned int nIn, unsigned int flags, int nHashType);
646 // Given two sets of signatures for scriptPubKey, possibly with OP_0 placeholders,
647 // combine them intelligently and return the result.
648 CScript CombineSignatures(const CScript& scriptPubKey, const CTransaction& txTo, unsigned int nIn, const CScript& scriptSig1, const CScript& scriptSig2);