/src/script/standard.cpp
C++ | 318 lines | 253 code | 39 blank | 26 comment | 78 complexity | e563e9953dc3fc56635a86af669092a3 MD5 | raw file
- // Copyright (c) 2009-2010 Satoshi Nakamoto
- // Copyright (c) 2009-2014 The Bitcoin developers
- // Distributed under the MIT software license, see the accompanying
- // file COPYING or http://www.opensource.org/licenses/mit-license.php.
- #include "script/standard.h"
- #include "pubkey.h"
- #include "script/script.h"
- #include "util.h"
- #include "utilstrencodings.h"
- #include <boost/foreach.hpp>
- using namespace std;
- typedef vector<unsigned char> valtype;
- unsigned nMaxDatacarrierBytes = MAX_OP_RETURN_RELAY;
- CScriptID::CScriptID(const CScript& in) : uint160(in.size() ? Hash160(in.begin(), in.end()) : 0) {}
- const char* GetTxnOutputType(txnouttype t)
- {
- switch (t)
- {
- case TX_NONSTANDARD: return "nonstandard";
- case TX_PUBKEY: return "pubkey";
- case TX_PUBKEYHASH: return "pubkeyhash";
- case TX_SCRIPTHASH: return "scripthash";
- case TX_MULTISIG: return "multisig";
- case TX_NULL_DATA: return "nulldata";
- }
- return NULL;
- }
- /**
- * Return public keys or hashes from scriptPubKey, for 'standard' transaction types.
- */
- bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, vector<vector<unsigned char> >& vSolutionsRet)
- {
- // Templates
- static multimap<txnouttype, CScript> mTemplates;
- if (mTemplates.empty())
- {
- // Standard tx, sender provides pubkey, receiver adds signature
- mTemplates.insert(make_pair(TX_PUBKEY, CScript() << OP_PUBKEY << OP_CHECKSIG));
- // Bitcoin address tx, sender provides hash of pubkey, receiver provides signature and pubkey
- mTemplates.insert(make_pair(TX_PUBKEYHASH, CScript() << OP_DUP << OP_HASH160 << OP_PUBKEYHASH << OP_EQUALVERIFY << OP_CHECKSIG));
- // Sender provides N pubkeys, receivers provides M signatures
- mTemplates.insert(make_pair(TX_MULTISIG, CScript() << OP_SMALLINTEGER << OP_PUBKEYS << OP_SMALLINTEGER << OP_CHECKMULTISIG));
- // Empty, provably prunable, data-carrying output
- if (GetBoolArg("-datacarrier", true))
- mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN << OP_SMALLDATA));
- mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN));
- }
- // Shortcut for pay-to-script-hash, which are more constrained than the other types:
- // it is always OP_HASH160 20 [20 byte hash] OP_EQUAL
- if (scriptPubKey.IsPayToScriptHash())
- {
- typeRet = TX_SCRIPTHASH;
- vector<unsigned char> hashBytes(scriptPubKey.begin()+2, scriptPubKey.begin()+22);
- vSolutionsRet.push_back(hashBytes);
- return true;
- }
- // Scan templates
- const CScript& script1 = scriptPubKey;
- BOOST_FOREACH(const PAIRTYPE(txnouttype, CScript)& tplate, mTemplates)
- {
- const CScript& script2 = tplate.second;
- vSolutionsRet.clear();
- opcodetype opcode1, opcode2;
- vector<unsigned char> vch1, vch2;
- // Compare
- CScript::const_iterator pc1 = script1.begin();
- CScript::const_iterator pc2 = script2.begin();
- while (true)
- {
- if (pc1 == script1.end() && pc2 == script2.end())
- {
- // Found a match
- typeRet = tplate.first;
- if (typeRet == TX_MULTISIG)
- {
- // Additional checks for TX_MULTISIG:
- unsigned char m = vSolutionsRet.front()[0];
- unsigned char n = vSolutionsRet.back()[0];
- if (m < 1 || n < 1 || m > n || vSolutionsRet.size()-2 != n)
- return false;
- }
- return true;
- }
- if (!script1.GetOp(pc1, opcode1, vch1))
- break;
- if (!script2.GetOp(pc2, opcode2, vch2))
- break;
- // Template matching opcodes:
- if (opcode2 == OP_PUBKEYS)
- {
- while (vch1.size() >= 33 && vch1.size() <= 65)
- {
- vSolutionsRet.push_back(vch1);
- if (!script1.GetOp(pc1, opcode1, vch1))
- break;
- }
- if (!script2.GetOp(pc2, opcode2, vch2))
- break;
- // Normal situation is to fall through
- // to other if/else statements
- }
- if (opcode2 == OP_PUBKEY)
- {
- if (vch1.size() < 33 || vch1.size() > 65)
- break;
- vSolutionsRet.push_back(vch1);
- }
- else if (opcode2 == OP_PUBKEYHASH)
- {
- if (vch1.size() != sizeof(uint160))
- break;
- vSolutionsRet.push_back(vch1);
- }
- else if (opcode2 == OP_SMALLINTEGER)
- { // Single-byte small integer pushed onto vSolutions
- if (opcode1 == OP_0 ||
- (opcode1 >= OP_1 && opcode1 <= OP_16))
- {
- char n = (char)CScript::DecodeOP_N(opcode1);
- vSolutionsRet.push_back(valtype(1, n));
- }
- else
- break;
- }
- else if (opcode2 == OP_SMALLDATA)
- {
- // small pushdata, <= nMaxDatacarrierBytes
- if (vch1.size() > nMaxDatacarrierBytes)
- break;
- }
- else if (opcode1 != opcode2 || vch1 != vch2)
- {
- // Others must match exactly
- break;
- }
- }
- }
- vSolutionsRet.clear();
- typeRet = TX_NONSTANDARD;
- return false;
- }
- int ScriptSigArgsExpected(txnouttype t, const std::vector<std::vector<unsigned char> >& vSolutions)
- {
- switch (t)
- {
- case TX_NONSTANDARD:
- case TX_NULL_DATA:
- return -1;
- case TX_PUBKEY:
- return 1;
- case TX_PUBKEYHASH:
- return 2;
- case TX_MULTISIG:
- if (vSolutions.size() < 1 || vSolutions[0].size() < 1)
- return -1;
- return vSolutions[0][0] + 1;
- case TX_SCRIPTHASH:
- return 1; // doesn't include args needed by the script
- }
- return -1;
- }
- bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType)
- {
- vector<valtype> vSolutions;
- if (!Solver(scriptPubKey, whichType, vSolutions))
- return false;
- if (whichType == TX_MULTISIG)
- {
- unsigned char m = vSolutions.front()[0];
- unsigned char n = vSolutions.back()[0];
- // Support up to x-of-3 multisig txns as standard
- if (n < 1 || n > 3)
- return false;
- if (m < 1 || m > n)
- return false;
- }
- return whichType != TX_NONSTANDARD;
- }
- bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
- {
- vector<valtype> vSolutions;
- txnouttype whichType;
- if (!Solver(scriptPubKey, whichType, vSolutions))
- return false;
- if (whichType == TX_PUBKEY)
- {
- CPubKey pubKey(vSolutions[0]);
- if (!pubKey.IsValid())
- return false;
- addressRet = pubKey.GetID();
- return true;
- }
- else if (whichType == TX_PUBKEYHASH)
- {
- addressRet = CKeyID(uint160(vSolutions[0]));
- return true;
- }
- else if (whichType == TX_SCRIPTHASH)
- {
- addressRet = CScriptID(uint160(vSolutions[0]));
- return true;
- }
- // Multisig txns have more than one address...
- return false;
- }
- bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, vector<CTxDestination>& addressRet, int& nRequiredRet)
- {
- addressRet.clear();
- typeRet = TX_NONSTANDARD;
- vector<valtype> vSolutions;
- if (!Solver(scriptPubKey, typeRet, vSolutions))
- return false;
- if (typeRet == TX_NULL_DATA){
- // This is data, not addresses
- return false;
- }
- if (typeRet == TX_MULTISIG)
- {
- nRequiredRet = vSolutions.front()[0];
- for (unsigned int i = 1; i < vSolutions.size()-1; i++)
- {
- CPubKey pubKey(vSolutions[i]);
- if (!pubKey.IsValid())
- continue;
- CTxDestination address = pubKey.GetID();
- addressRet.push_back(address);
- }
- if (addressRet.empty())
- return false;
- }
- else
- {
- nRequiredRet = 1;
- CTxDestination address;
- if (!ExtractDestination(scriptPubKey, address))
- return false;
- addressRet.push_back(address);
- }
- return true;
- }
- namespace
- {
- class CScriptVisitor : public boost::static_visitor<bool>
- {
- private:
- CScript *script;
- public:
- CScriptVisitor(CScript *scriptin) { script = scriptin; }
- bool operator()(const CNoDestination &dest) const {
- script->clear();
- return false;
- }
- bool operator()(const CKeyID &keyID) const {
- script->clear();
- *script << OP_DUP << OP_HASH160 << ToByteVector(keyID) << OP_EQUALVERIFY << OP_CHECKSIG;
- return true;
- }
- bool operator()(const CScriptID &scriptID) const {
- script->clear();
- *script << OP_HASH160 << ToByteVector(scriptID) << OP_EQUAL;
- return true;
- }
- };
- }
- CScript GetScriptForDestination(const CTxDestination& dest)
- {
- CScript script;
- boost::apply_visitor(CScriptVisitor(&script), dest);
- return script;
- }
- CScript GetScriptForMultisig(int nRequired, const std::vector<CPubKey>& keys)
- {
- CScript script;
- script << CScript::EncodeOP_N(nRequired);
- BOOST_FOREACH(const CPubKey& key, keys)
- script << ToByteVector(key);
- script << CScript::EncodeOP_N(keys.size()) << OP_CHECKMULTISIG;
- return script;
- }