dash/src/script/standard.cpp

286 lines
8.8 KiB
C++

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2020 The Bitcoin Core 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 <string>
typedef std::vector<unsigned char> valtype;
bool fAcceptDatacarrier = DEFAULT_ACCEPT_DATACARRIER;
unsigned nMaxDatacarrierBytes = MAX_OP_RETURN_RELAY;
CScriptID::CScriptID(const CScript& in) : BaseHash(Hash160(in)) {}
CScriptID::CScriptID(const ScriptHash& in) : BaseHash(static_cast<uint160>(in)) {}
ScriptHash::ScriptHash(const CScript& in) : BaseHash(Hash160(in)) {}
ScriptHash::ScriptHash(const CScriptID& in) : BaseHash(static_cast<uint160>(in)) {}
PKHash::PKHash(const CPubKey& pubkey) : BaseHash(pubkey.GetID()) {}
PKHash::PKHash(const CKeyID& pubkey_id) : BaseHash(pubkey_id) {}
CKeyID ToKeyID(const PKHash& key_hash)
{
return CKeyID{static_cast<uint160>(key_hash)};
}
std::string GetTxnOutputType(TxoutType t)
{
switch (t) {
case TxoutType::NONSTANDARD: return "nonstandard";
case TxoutType::PUBKEY: return "pubkey";
case TxoutType::PUBKEYHASH: return "pubkeyhash";
case TxoutType::SCRIPTHASH: return "scripthash";
case TxoutType::MULTISIG: return "multisig";
case TxoutType::NULL_DATA: return "nulldata";
} // no default case, so the compiler can warn about missing cases
assert(false);
}
static bool MatchPayToPubkey(const CScript& script, valtype& pubkey)
{
if (script.size() == CPubKey::SIZE + 2 && script[0] == CPubKey::SIZE && script.back() == OP_CHECKSIG) {
pubkey = valtype(script.begin() + 1, script.begin() + CPubKey::SIZE + 1);
return CPubKey::ValidSize(pubkey);
}
if (script.size() == CPubKey::COMPRESSED_SIZE + 2 && script[0] == CPubKey::COMPRESSED_SIZE && script.back() == OP_CHECKSIG) {
pubkey = valtype(script.begin() + 1, script.begin() + CPubKey::COMPRESSED_SIZE + 1);
return CPubKey::ValidSize(pubkey);
}
return false;
}
static bool MatchPayToPubkeyHash(const CScript& script, valtype& pubkeyhash)
{
if (script.size() == 25 && script[0] == OP_DUP && script[1] == OP_HASH160 && script[2] == 20 && script[23] == OP_EQUALVERIFY && script[24] == OP_CHECKSIG) {
pubkeyhash = valtype(script.begin () + 3, script.begin() + 23);
return true;
}
return false;
}
/** Test for "small positive integer" script opcodes - OP_1 through OP_16. */
static constexpr bool IsSmallInteger(opcodetype opcode)
{
return opcode >= OP_1 && opcode <= OP_16;
}
static constexpr bool IsPushdataOp(opcodetype opcode)
{
return opcode > OP_FALSE && opcode <= OP_PUSHDATA4;
}
static constexpr bool IsValidMultisigKeyCount(int n_keys)
{
return n_keys > 0 && n_keys <= MAX_PUBKEYS_PER_MULTISIG;
}
static bool GetMultisigKeyCount(opcodetype opcode, valtype data, int& count)
{
if (IsSmallInteger(opcode)) {
count = CScript::DecodeOP_N(opcode);
return IsValidMultisigKeyCount(count);
}
if (IsPushdataOp(opcode)) {
if (!CheckMinimalPush(data, opcode)) return false;
try {
count = CScriptNum(data, /* fRequireMinimal = */ true).getint();
return IsValidMultisigKeyCount(count);
} catch (const scriptnum_error&) {
return false;
}
}
return false;
}
static bool MatchMultisig(const CScript& script, int& required_sigs, std::vector<valtype>& pubkeys)
{
opcodetype opcode;
valtype data;
int num_keys;
CScript::const_iterator it = script.begin();
if (script.size() < 1 || script.back() != OP_CHECKMULTISIG) return false;
if (!script.GetOp(it, opcode, data) || !GetMultisigKeyCount(opcode, data, required_sigs)) return false;
while (script.GetOp(it, opcode, data) && CPubKey::ValidSize(data)) {
pubkeys.emplace_back(std::move(data));
}
if (!GetMultisigKeyCount(opcode, data, num_keys)) return false;
if (pubkeys.size() != static_cast<unsigned long>(num_keys) || num_keys < required_sigs) return false;
return (it + 1 == script.end());
}
TxoutType Solver(const CScript& scriptPubKey, std::vector<std::vector<unsigned char>>& vSolutionsRet)
{
vSolutionsRet.clear();
// 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())
{
std::vector<unsigned char> hashBytes(scriptPubKey.begin()+2, scriptPubKey.begin()+22);
vSolutionsRet.push_back(hashBytes);
return TxoutType::SCRIPTHASH;
}
// Provably prunable, data-carrying output
//
// So long as script passes the IsUnspendable() test and all but the first
// byte passes the IsPushOnly() test we don't care what exactly is in the
// script.
if (scriptPubKey.size() >= 1 && scriptPubKey[0] == OP_RETURN && scriptPubKey.IsPushOnly(scriptPubKey.begin()+1)) {
return TxoutType::NULL_DATA;
}
std::vector<unsigned char> data;
if (MatchPayToPubkey(scriptPubKey, data)) {
vSolutionsRet.push_back(std::move(data));
return TxoutType::PUBKEY;
}
if (MatchPayToPubkeyHash(scriptPubKey, data)) {
vSolutionsRet.push_back(std::move(data));
return TxoutType::PUBKEYHASH;
}
int required;
std::vector<std::vector<unsigned char>> keys;
if (MatchMultisig(scriptPubKey, required, keys)) {
vSolutionsRet.push_back({static_cast<unsigned char>(required)}); // safe as required is in range 1..20
vSolutionsRet.insert(vSolutionsRet.end(), keys.begin(), keys.end());
vSolutionsRet.push_back({static_cast<unsigned char>(keys.size())}); // safe as size is in range 1..20
return TxoutType::MULTISIG;
}
vSolutionsRet.clear();
return TxoutType::NONSTANDARD;
}
bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
{
std::vector<valtype> vSolutions;
TxoutType whichType = Solver(scriptPubKey, vSolutions);
switch (whichType) {
case TxoutType::PUBKEY: {
CPubKey pubKey(vSolutions[0]);
if (!pubKey.IsValid())
return false;
addressRet = PKHash(pubKey);
return true;
}
case TxoutType::PUBKEYHASH: {
addressRet = PKHash(uint160(vSolutions[0]));
return true;
}
case TxoutType::SCRIPTHASH: {
addressRet = ScriptHash(uint160(vSolutions[0]));
return true;
}
case TxoutType::MULTISIG:
case TxoutType::NULL_DATA:
case TxoutType::NONSTANDARD:
return false;
} // no default case, so the compiler can warn about missing cases
assert(false);
}
// TODO: from v21 ("addresses" and "reqSigs" deprecated) "ExtractDestinations" should be removed
bool ExtractDestinations(const CScript& scriptPubKey, TxoutType& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet)
{
addressRet.clear();
std::vector<valtype> vSolutions;
typeRet = Solver(scriptPubKey, vSolutions);
if (typeRet == TxoutType::NONSTANDARD) {
return false;
} else if (typeRet == TxoutType::NULL_DATA) {
// This is data, not addresses
return false;
}
if (typeRet == TxoutType::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 = PKHash(pubKey);
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:
CScript operator()(const CNoDestination& dest) const
{
return CScript();
}
CScript operator()(const PKHash& keyID) const
{
return CScript() << OP_DUP << OP_HASH160 << ToByteVector(keyID) << OP_EQUALVERIFY << OP_CHECKSIG;
}
CScript operator()(const ScriptHash& scriptID) const
{
return CScript() << OP_HASH160 << ToByteVector(scriptID) << OP_EQUAL;
}
};
} // namespace
CScript GetScriptForDestination(const CTxDestination& dest)
{
return std::visit(CScriptVisitor(), dest);
}
CScript GetScriptForRawPubKey(const CPubKey& pubKey)
{
return CScript() << std::vector<unsigned char>(pubKey.begin(), pubKey.end()) << OP_CHECKSIG;
}
CScript GetScriptForMultisig(int nRequired, const std::vector<CPubKey>& keys)
{
CScript script;
script << nRequired;
for (const CPubKey& key : keys)
script << ToByteVector(key);
script << keys.size() << OP_CHECKMULTISIG;
return script;
}
bool IsValidDestination(const CTxDestination& dest) {
return dest.index() != 0;
}