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![Andrew Chow](/assets/img/avatar_default.png)
The places where we need to lookup information for a XOnlyPubKey currently implement a hack which makes both serializations of the full pubkey in order to try the CKeyIDs for the lookup functions. Instead of duplicating this everywhere it is needed, we can consolidate the CKeyID generation into a function, and then have wrappers around GetPubKey, GetKey, and GetKeyOrigin which takes the XOnlyPubKey, retrieves all of the CKeyIDs (using the new GetKeyIDs() function in XOnlyPubKey), and tries their respective underlying lookup function.
684 lines
28 KiB
C++
684 lines
28 KiB
C++
// Copyright (c) 2009-2010 Satoshi Nakamoto
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// Copyright (c) 2009-2020 The Bitcoin Core developers
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// Distributed under the MIT software license, see the accompanying
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// file COPYING or http://www.opensource.org/licenses/mit-license.php.
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#include <script/sign.h>
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#include <key.h>
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#include <policy/policy.h>
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#include <primitives/transaction.h>
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#include <script/signingprovider.h>
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#include <script/standard.h>
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#include <uint256.h>
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#include <util/translation.h>
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#include <util/vector.h>
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typedef std::vector<unsigned char> valtype;
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MutableTransactionSignatureCreator::MutableTransactionSignatureCreator(const CMutableTransaction* txToIn, unsigned int nInIn, const CAmount& amountIn, int nHashTypeIn)
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: txTo(txToIn), nIn(nInIn), nHashType(nHashTypeIn), amount(amountIn), checker(txTo, nIn, amountIn, MissingDataBehavior::FAIL),
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m_txdata(nullptr)
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{
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}
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MutableTransactionSignatureCreator::MutableTransactionSignatureCreator(const CMutableTransaction* txToIn, unsigned int nInIn, const CAmount& amountIn, const PrecomputedTransactionData* txdata, int nHashTypeIn)
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: txTo(txToIn), nIn(nInIn), nHashType(nHashTypeIn), amount(amountIn),
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checker(txdata ? MutableTransactionSignatureChecker(txTo, nIn, amount, *txdata, MissingDataBehavior::FAIL) :
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MutableTransactionSignatureChecker(txTo, nIn, amount, MissingDataBehavior::FAIL)),
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m_txdata(txdata)
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{
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}
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bool MutableTransactionSignatureCreator::CreateSig(const SigningProvider& provider, std::vector<unsigned char>& vchSig, const CKeyID& address, const CScript& scriptCode, SigVersion sigversion) const
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{
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assert(sigversion == SigVersion::BASE || sigversion == SigVersion::WITNESS_V0);
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CKey key;
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if (!provider.GetKey(address, key))
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return false;
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// Signing with uncompressed keys is disabled in witness scripts
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if (sigversion == SigVersion::WITNESS_V0 && !key.IsCompressed())
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return false;
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// Signing without known amount does not work in witness scripts.
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if (sigversion == SigVersion::WITNESS_V0 && !MoneyRange(amount)) return false;
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// BASE/WITNESS_V0 signatures don't support explicit SIGHASH_DEFAULT, use SIGHASH_ALL instead.
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const int hashtype = nHashType == SIGHASH_DEFAULT ? SIGHASH_ALL : nHashType;
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uint256 hash = SignatureHash(scriptCode, *txTo, nIn, hashtype, amount, sigversion, m_txdata);
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if (!key.Sign(hash, vchSig))
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return false;
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vchSig.push_back((unsigned char)hashtype);
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return true;
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}
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bool MutableTransactionSignatureCreator::CreateSchnorrSig(const SigningProvider& provider, std::vector<unsigned char>& sig, const XOnlyPubKey& pubkey, const uint256* leaf_hash, const uint256* merkle_root, SigVersion sigversion) const
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{
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assert(sigversion == SigVersion::TAPROOT || sigversion == SigVersion::TAPSCRIPT);
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CKey key;
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if (!provider.GetKeyByXOnly(pubkey, key)) return false;
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// BIP341/BIP342 signing needs lots of precomputed transaction data. While some
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// (non-SIGHASH_DEFAULT) sighash modes exist that can work with just some subset
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// of data present, for now, only support signing when everything is provided.
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if (!m_txdata || !m_txdata->m_bip341_taproot_ready || !m_txdata->m_spent_outputs_ready) return false;
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ScriptExecutionData execdata;
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execdata.m_annex_init = true;
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execdata.m_annex_present = false; // Only support annex-less signing for now.
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if (sigversion == SigVersion::TAPSCRIPT) {
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execdata.m_codeseparator_pos_init = true;
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execdata.m_codeseparator_pos = 0xFFFFFFFF; // Only support non-OP_CODESEPARATOR BIP342 signing for now.
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if (!leaf_hash) return false; // BIP342 signing needs leaf hash.
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execdata.m_tapleaf_hash_init = true;
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execdata.m_tapleaf_hash = *leaf_hash;
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}
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uint256 hash;
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if (!SignatureHashSchnorr(hash, execdata, *txTo, nIn, nHashType, sigversion, *m_txdata, MissingDataBehavior::FAIL)) return false;
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sig.resize(64);
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if (!key.SignSchnorr(hash, sig, merkle_root, nullptr)) return false;
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if (nHashType) sig.push_back(nHashType);
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return true;
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}
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static bool GetCScript(const SigningProvider& provider, const SignatureData& sigdata, const CScriptID& scriptid, CScript& script)
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{
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if (provider.GetCScript(scriptid, script)) {
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return true;
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}
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// Look for scripts in SignatureData
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if (CScriptID(sigdata.redeem_script) == scriptid) {
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script = sigdata.redeem_script;
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return true;
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} else if (CScriptID(sigdata.witness_script) == scriptid) {
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script = sigdata.witness_script;
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return true;
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}
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return false;
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}
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static bool GetPubKey(const SigningProvider& provider, const SignatureData& sigdata, const CKeyID& address, CPubKey& pubkey)
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{
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// Look for pubkey in all partial sigs
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const auto it = sigdata.signatures.find(address);
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if (it != sigdata.signatures.end()) {
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pubkey = it->second.first;
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return true;
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}
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// Look for pubkey in pubkey list
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const auto& pk_it = sigdata.misc_pubkeys.find(address);
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if (pk_it != sigdata.misc_pubkeys.end()) {
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pubkey = pk_it->second.first;
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return true;
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}
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// Query the underlying provider
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return provider.GetPubKey(address, pubkey);
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}
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static bool CreateSig(const BaseSignatureCreator& creator, SignatureData& sigdata, const SigningProvider& provider, std::vector<unsigned char>& sig_out, const CPubKey& pubkey, const CScript& scriptcode, SigVersion sigversion)
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{
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CKeyID keyid = pubkey.GetID();
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const auto it = sigdata.signatures.find(keyid);
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if (it != sigdata.signatures.end()) {
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sig_out = it->second.second;
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return true;
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}
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KeyOriginInfo info;
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if (provider.GetKeyOrigin(keyid, info)) {
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sigdata.misc_pubkeys.emplace(keyid, std::make_pair(pubkey, std::move(info)));
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}
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if (creator.CreateSig(provider, sig_out, keyid, scriptcode, sigversion)) {
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auto i = sigdata.signatures.emplace(keyid, SigPair(pubkey, sig_out));
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assert(i.second);
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return true;
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}
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// Could not make signature or signature not found, add keyid to missing
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sigdata.missing_sigs.push_back(keyid);
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return false;
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}
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static bool CreateTaprootScriptSig(const BaseSignatureCreator& creator, SignatureData& sigdata, const SigningProvider& provider, std::vector<unsigned char>& sig_out, const XOnlyPubKey& pubkey, const uint256& leaf_hash, SigVersion sigversion)
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{
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auto lookup_key = std::make_pair(pubkey, leaf_hash);
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auto it = sigdata.taproot_script_sigs.find(lookup_key);
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if (it != sigdata.taproot_script_sigs.end()) {
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sig_out = it->second;
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}
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if (creator.CreateSchnorrSig(provider, sig_out, pubkey, &leaf_hash, nullptr, sigversion)) {
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sigdata.taproot_script_sigs[lookup_key] = sig_out;
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return true;
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}
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return false;
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}
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static bool SignTaprootScript(const SigningProvider& provider, const BaseSignatureCreator& creator, SignatureData& sigdata, int leaf_version, const CScript& script, std::vector<valtype>& result)
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{
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// Only BIP342 tapscript signing is supported for now.
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if (leaf_version != TAPROOT_LEAF_TAPSCRIPT) return false;
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SigVersion sigversion = SigVersion::TAPSCRIPT;
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uint256 leaf_hash = (CHashWriter(HASHER_TAPLEAF) << uint8_t(leaf_version) << script).GetSHA256();
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// <xonly pubkey> OP_CHECKSIG
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if (script.size() == 34 && script[33] == OP_CHECKSIG && script[0] == 0x20) {
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XOnlyPubKey pubkey(MakeSpan(script).subspan(1, 32));
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std::vector<unsigned char> sig;
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if (CreateTaprootScriptSig(creator, sigdata, provider, sig, pubkey, leaf_hash, sigversion)) {
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result = Vector(std::move(sig));
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return true;
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}
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}
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return false;
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}
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static bool SignTaproot(const SigningProvider& provider, const BaseSignatureCreator& creator, const WitnessV1Taproot& output, SignatureData& sigdata, std::vector<valtype>& result)
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{
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TaprootSpendData spenddata;
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// Gather information about this output.
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if (provider.GetTaprootSpendData(output, spenddata)) {
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sigdata.tr_spenddata.Merge(spenddata);
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}
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// Try key path spending.
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{
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std::vector<unsigned char> sig;
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if (sigdata.taproot_key_path_sig.size() == 0) {
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if (creator.CreateSchnorrSig(provider, sig, spenddata.internal_key, nullptr, &spenddata.merkle_root, SigVersion::TAPROOT)) {
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sigdata.taproot_key_path_sig = sig;
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}
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}
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if (sigdata.taproot_key_path_sig.size()) {
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result = Vector(sigdata.taproot_key_path_sig);
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return true;
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}
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}
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// Try script path spending.
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std::vector<std::vector<unsigned char>> smallest_result_stack;
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for (const auto& [key, control_blocks] : sigdata.tr_spenddata.scripts) {
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const auto& [script, leaf_ver] = key;
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std::vector<std::vector<unsigned char>> result_stack;
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if (SignTaprootScript(provider, creator, sigdata, leaf_ver, script, result_stack)) {
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result_stack.emplace_back(std::begin(script), std::end(script)); // Push the script
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result_stack.push_back(*control_blocks.begin()); // Push the smallest control block
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if (smallest_result_stack.size() == 0 ||
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GetSerializeSize(result_stack, PROTOCOL_VERSION) < GetSerializeSize(smallest_result_stack, PROTOCOL_VERSION)) {
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smallest_result_stack = std::move(result_stack);
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}
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}
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}
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if (smallest_result_stack.size() != 0) {
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result = std::move(smallest_result_stack);
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return true;
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}
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return false;
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}
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/**
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* Sign scriptPubKey using signature made with creator.
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* Signatures are returned in scriptSigRet (or returns false if scriptPubKey can't be signed),
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* unless whichTypeRet is TxoutType::SCRIPTHASH, in which case scriptSigRet is the redemption script.
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* Returns false if scriptPubKey could not be completely satisfied.
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*/
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static bool SignStep(const SigningProvider& provider, const BaseSignatureCreator& creator, const CScript& scriptPubKey,
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std::vector<valtype>& ret, TxoutType& whichTypeRet, SigVersion sigversion, SignatureData& sigdata)
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{
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CScript scriptRet;
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uint160 h160;
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ret.clear();
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std::vector<unsigned char> sig;
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std::vector<valtype> vSolutions;
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whichTypeRet = Solver(scriptPubKey, vSolutions);
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switch (whichTypeRet) {
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case TxoutType::NONSTANDARD:
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case TxoutType::NULL_DATA:
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case TxoutType::WITNESS_UNKNOWN:
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return false;
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case TxoutType::PUBKEY:
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if (!CreateSig(creator, sigdata, provider, sig, CPubKey(vSolutions[0]), scriptPubKey, sigversion)) return false;
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ret.push_back(std::move(sig));
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return true;
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case TxoutType::PUBKEYHASH: {
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CKeyID keyID = CKeyID(uint160(vSolutions[0]));
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CPubKey pubkey;
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if (!GetPubKey(provider, sigdata, keyID, pubkey)) {
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// Pubkey could not be found, add to missing
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sigdata.missing_pubkeys.push_back(keyID);
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return false;
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}
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if (!CreateSig(creator, sigdata, provider, sig, pubkey, scriptPubKey, sigversion)) return false;
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ret.push_back(std::move(sig));
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ret.push_back(ToByteVector(pubkey));
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return true;
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}
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case TxoutType::SCRIPTHASH:
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h160 = uint160(vSolutions[0]);
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if (GetCScript(provider, sigdata, CScriptID{h160}, scriptRet)) {
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ret.push_back(std::vector<unsigned char>(scriptRet.begin(), scriptRet.end()));
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return true;
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}
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// Could not find redeemScript, add to missing
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sigdata.missing_redeem_script = h160;
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return false;
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case TxoutType::MULTISIG: {
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size_t required = vSolutions.front()[0];
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ret.push_back(valtype()); // workaround CHECKMULTISIG bug
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for (size_t i = 1; i < vSolutions.size() - 1; ++i) {
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CPubKey pubkey = CPubKey(vSolutions[i]);
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// We need to always call CreateSig in order to fill sigdata with all
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// possible signatures that we can create. This will allow further PSBT
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// processing to work as it needs all possible signature and pubkey pairs
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if (CreateSig(creator, sigdata, provider, sig, pubkey, scriptPubKey, sigversion)) {
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if (ret.size() < required + 1) {
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ret.push_back(std::move(sig));
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}
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}
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}
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bool ok = ret.size() == required + 1;
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for (size_t i = 0; i + ret.size() < required + 1; ++i) {
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ret.push_back(valtype());
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}
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return ok;
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}
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case TxoutType::WITNESS_V0_KEYHASH:
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ret.push_back(vSolutions[0]);
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return true;
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case TxoutType::WITNESS_V0_SCRIPTHASH:
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CRIPEMD160().Write(vSolutions[0].data(), vSolutions[0].size()).Finalize(h160.begin());
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if (GetCScript(provider, sigdata, CScriptID{h160}, scriptRet)) {
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ret.push_back(std::vector<unsigned char>(scriptRet.begin(), scriptRet.end()));
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return true;
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}
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// Could not find witnessScript, add to missing
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sigdata.missing_witness_script = uint256(vSolutions[0]);
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return false;
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case TxoutType::WITNESS_V1_TAPROOT:
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return SignTaproot(provider, creator, WitnessV1Taproot(XOnlyPubKey{vSolutions[0]}), sigdata, ret);
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} // no default case, so the compiler can warn about missing cases
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assert(false);
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}
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static CScript PushAll(const std::vector<valtype>& values)
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{
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CScript result;
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for (const valtype& v : values) {
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if (v.size() == 0) {
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result << OP_0;
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} else if (v.size() == 1 && v[0] >= 1 && v[0] <= 16) {
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result << CScript::EncodeOP_N(v[0]);
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} else if (v.size() == 1 && v[0] == 0x81) {
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result << OP_1NEGATE;
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} else {
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result << v;
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}
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}
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return result;
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}
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bool ProduceSignature(const SigningProvider& provider, const BaseSignatureCreator& creator, const CScript& fromPubKey, SignatureData& sigdata)
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{
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if (sigdata.complete) return true;
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std::vector<valtype> result;
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TxoutType whichType;
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bool solved = SignStep(provider, creator, fromPubKey, result, whichType, SigVersion::BASE, sigdata);
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bool P2SH = false;
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CScript subscript;
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if (solved && whichType == TxoutType::SCRIPTHASH)
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{
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// Solver returns the subscript that needs to be evaluated;
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// the final scriptSig is the signatures from that
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// and then the serialized subscript:
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subscript = CScript(result[0].begin(), result[0].end());
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sigdata.redeem_script = subscript;
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solved = solved && SignStep(provider, creator, subscript, result, whichType, SigVersion::BASE, sigdata) && whichType != TxoutType::SCRIPTHASH;
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P2SH = true;
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}
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if (solved && whichType == TxoutType::WITNESS_V0_KEYHASH)
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{
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CScript witnessscript;
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witnessscript << OP_DUP << OP_HASH160 << ToByteVector(result[0]) << OP_EQUALVERIFY << OP_CHECKSIG;
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TxoutType subType;
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solved = solved && SignStep(provider, creator, witnessscript, result, subType, SigVersion::WITNESS_V0, sigdata);
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sigdata.scriptWitness.stack = result;
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sigdata.witness = true;
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result.clear();
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}
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else if (solved && whichType == TxoutType::WITNESS_V0_SCRIPTHASH)
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{
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CScript witnessscript(result[0].begin(), result[0].end());
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sigdata.witness_script = witnessscript;
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TxoutType subType;
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solved = solved && SignStep(provider, creator, witnessscript, result, subType, SigVersion::WITNESS_V0, sigdata) && subType != TxoutType::SCRIPTHASH && subType != TxoutType::WITNESS_V0_SCRIPTHASH && subType != TxoutType::WITNESS_V0_KEYHASH;
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result.push_back(std::vector<unsigned char>(witnessscript.begin(), witnessscript.end()));
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sigdata.scriptWitness.stack = result;
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sigdata.witness = true;
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result.clear();
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} else if (whichType == TxoutType::WITNESS_V1_TAPROOT && !P2SH) {
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sigdata.witness = true;
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if (solved) {
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sigdata.scriptWitness.stack = std::move(result);
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}
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result.clear();
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} else if (solved && whichType == TxoutType::WITNESS_UNKNOWN) {
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sigdata.witness = true;
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}
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if (!sigdata.witness) sigdata.scriptWitness.stack.clear();
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if (P2SH) {
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result.push_back(std::vector<unsigned char>(subscript.begin(), subscript.end()));
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}
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sigdata.scriptSig = PushAll(result);
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// Test solution
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sigdata.complete = solved && VerifyScript(sigdata.scriptSig, fromPubKey, &sigdata.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, creator.Checker());
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return sigdata.complete;
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}
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namespace {
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class SignatureExtractorChecker final : public DeferringSignatureChecker
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{
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private:
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SignatureData& sigdata;
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public:
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SignatureExtractorChecker(SignatureData& sigdata, BaseSignatureChecker& checker) : DeferringSignatureChecker(checker), sigdata(sigdata) {}
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bool CheckECDSASignature(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode, SigVersion sigversion) const override
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{
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if (m_checker.CheckECDSASignature(scriptSig, vchPubKey, scriptCode, sigversion)) {
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CPubKey pubkey(vchPubKey);
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sigdata.signatures.emplace(pubkey.GetID(), SigPair(pubkey, scriptSig));
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return true;
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}
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return false;
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}
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};
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struct Stacks
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{
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std::vector<valtype> script;
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std::vector<valtype> witness;
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Stacks() = delete;
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Stacks(const Stacks&) = delete;
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explicit Stacks(const SignatureData& data) : witness(data.scriptWitness.stack) {
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EvalScript(script, data.scriptSig, SCRIPT_VERIFY_STRICTENC, BaseSignatureChecker(), SigVersion::BASE);
|
|
}
|
|
};
|
|
}
|
|
|
|
// Extracts signatures and scripts from incomplete scriptSigs. Please do not extend this, use PSBT instead
|
|
SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nIn, const CTxOut& txout)
|
|
{
|
|
SignatureData data;
|
|
assert(tx.vin.size() > nIn);
|
|
data.scriptSig = tx.vin[nIn].scriptSig;
|
|
data.scriptWitness = tx.vin[nIn].scriptWitness;
|
|
Stacks stack(data);
|
|
|
|
// Get signatures
|
|
MutableTransactionSignatureChecker tx_checker(&tx, nIn, txout.nValue, MissingDataBehavior::FAIL);
|
|
SignatureExtractorChecker extractor_checker(data, tx_checker);
|
|
if (VerifyScript(data.scriptSig, txout.scriptPubKey, &data.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, extractor_checker)) {
|
|
data.complete = true;
|
|
return data;
|
|
}
|
|
|
|
// Get scripts
|
|
std::vector<std::vector<unsigned char>> solutions;
|
|
TxoutType script_type = Solver(txout.scriptPubKey, solutions);
|
|
SigVersion sigversion = SigVersion::BASE;
|
|
CScript next_script = txout.scriptPubKey;
|
|
|
|
if (script_type == TxoutType::SCRIPTHASH && !stack.script.empty() && !stack.script.back().empty()) {
|
|
// Get the redeemScript
|
|
CScript redeem_script(stack.script.back().begin(), stack.script.back().end());
|
|
data.redeem_script = redeem_script;
|
|
next_script = std::move(redeem_script);
|
|
|
|
// Get redeemScript type
|
|
script_type = Solver(next_script, solutions);
|
|
stack.script.pop_back();
|
|
}
|
|
if (script_type == TxoutType::WITNESS_V0_SCRIPTHASH && !stack.witness.empty() && !stack.witness.back().empty()) {
|
|
// Get the witnessScript
|
|
CScript witness_script(stack.witness.back().begin(), stack.witness.back().end());
|
|
data.witness_script = witness_script;
|
|
next_script = std::move(witness_script);
|
|
|
|
// Get witnessScript type
|
|
script_type = Solver(next_script, solutions);
|
|
stack.witness.pop_back();
|
|
stack.script = std::move(stack.witness);
|
|
stack.witness.clear();
|
|
sigversion = SigVersion::WITNESS_V0;
|
|
}
|
|
if (script_type == TxoutType::MULTISIG && !stack.script.empty()) {
|
|
// Build a map of pubkey -> signature by matching sigs to pubkeys:
|
|
assert(solutions.size() > 1);
|
|
unsigned int num_pubkeys = solutions.size()-2;
|
|
unsigned int last_success_key = 0;
|
|
for (const valtype& sig : stack.script) {
|
|
for (unsigned int i = last_success_key; i < num_pubkeys; ++i) {
|
|
const valtype& pubkey = solutions[i+1];
|
|
// We either have a signature for this pubkey, or we have found a signature and it is valid
|
|
if (data.signatures.count(CPubKey(pubkey).GetID()) || extractor_checker.CheckECDSASignature(sig, pubkey, next_script, sigversion)) {
|
|
last_success_key = i + 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return data;
|
|
}
|
|
|
|
void UpdateInput(CTxIn& input, const SignatureData& data)
|
|
{
|
|
input.scriptSig = data.scriptSig;
|
|
input.scriptWitness = data.scriptWitness;
|
|
}
|
|
|
|
void SignatureData::MergeSignatureData(SignatureData sigdata)
|
|
{
|
|
if (complete) return;
|
|
if (sigdata.complete) {
|
|
*this = std::move(sigdata);
|
|
return;
|
|
}
|
|
if (redeem_script.empty() && !sigdata.redeem_script.empty()) {
|
|
redeem_script = sigdata.redeem_script;
|
|
}
|
|
if (witness_script.empty() && !sigdata.witness_script.empty()) {
|
|
witness_script = sigdata.witness_script;
|
|
}
|
|
signatures.insert(std::make_move_iterator(sigdata.signatures.begin()), std::make_move_iterator(sigdata.signatures.end()));
|
|
}
|
|
|
|
bool SignSignature(const SigningProvider &provider, const CScript& fromPubKey, CMutableTransaction& txTo, unsigned int nIn, const CAmount& amount, int nHashType)
|
|
{
|
|
assert(nIn < txTo.vin.size());
|
|
|
|
MutableTransactionSignatureCreator creator(&txTo, nIn, amount, nHashType);
|
|
|
|
SignatureData sigdata;
|
|
bool ret = ProduceSignature(provider, creator, fromPubKey, sigdata);
|
|
UpdateInput(txTo.vin.at(nIn), sigdata);
|
|
return ret;
|
|
}
|
|
|
|
bool SignSignature(const SigningProvider &provider, const CTransaction& txFrom, CMutableTransaction& txTo, unsigned int nIn, int nHashType)
|
|
{
|
|
assert(nIn < txTo.vin.size());
|
|
const CTxIn& txin = txTo.vin[nIn];
|
|
assert(txin.prevout.n < txFrom.vout.size());
|
|
const CTxOut& txout = txFrom.vout[txin.prevout.n];
|
|
|
|
return SignSignature(provider, txout.scriptPubKey, txTo, nIn, txout.nValue, nHashType);
|
|
}
|
|
|
|
namespace {
|
|
/** Dummy signature checker which accepts all signatures. */
|
|
class DummySignatureChecker final : public BaseSignatureChecker
|
|
{
|
|
public:
|
|
DummySignatureChecker() {}
|
|
bool CheckECDSASignature(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode, SigVersion sigversion) const override { return true; }
|
|
bool CheckSchnorrSignature(Span<const unsigned char> sig, Span<const unsigned char> pubkey, SigVersion sigversion, const ScriptExecutionData& execdata, ScriptError* serror) const override { return true; }
|
|
};
|
|
const DummySignatureChecker DUMMY_CHECKER;
|
|
|
|
class DummySignatureCreator final : public BaseSignatureCreator {
|
|
private:
|
|
char m_r_len = 32;
|
|
char m_s_len = 32;
|
|
public:
|
|
DummySignatureCreator(char r_len, char s_len) : m_r_len(r_len), m_s_len(s_len) {}
|
|
const BaseSignatureChecker& Checker() const override { return DUMMY_CHECKER; }
|
|
bool CreateSig(const SigningProvider& provider, std::vector<unsigned char>& vchSig, const CKeyID& keyid, const CScript& scriptCode, SigVersion sigversion) const override
|
|
{
|
|
// Create a dummy signature that is a valid DER-encoding
|
|
vchSig.assign(m_r_len + m_s_len + 7, '\000');
|
|
vchSig[0] = 0x30;
|
|
vchSig[1] = m_r_len + m_s_len + 4;
|
|
vchSig[2] = 0x02;
|
|
vchSig[3] = m_r_len;
|
|
vchSig[4] = 0x01;
|
|
vchSig[4 + m_r_len] = 0x02;
|
|
vchSig[5 + m_r_len] = m_s_len;
|
|
vchSig[6 + m_r_len] = 0x01;
|
|
vchSig[6 + m_r_len + m_s_len] = SIGHASH_ALL;
|
|
return true;
|
|
}
|
|
bool CreateSchnorrSig(const SigningProvider& provider, std::vector<unsigned char>& sig, const XOnlyPubKey& pubkey, const uint256* leaf_hash, const uint256* tweak, SigVersion sigversion) const override
|
|
{
|
|
sig.assign(64, '\000');
|
|
return true;
|
|
}
|
|
};
|
|
|
|
}
|
|
|
|
const BaseSignatureCreator& DUMMY_SIGNATURE_CREATOR = DummySignatureCreator(32, 32);
|
|
const BaseSignatureCreator& DUMMY_MAXIMUM_SIGNATURE_CREATOR = DummySignatureCreator(33, 32);
|
|
|
|
bool IsSolvable(const SigningProvider& provider, const CScript& script)
|
|
{
|
|
// This check is to make sure that the script we created can actually be solved for and signed by us
|
|
// if we were to have the private keys. This is just to make sure that the script is valid and that,
|
|
// if found in a transaction, we would still accept and relay that transaction. In particular,
|
|
// it will reject witness outputs that require signing with an uncompressed public key.
|
|
SignatureData sigs;
|
|
// Make sure that STANDARD_SCRIPT_VERIFY_FLAGS includes SCRIPT_VERIFY_WITNESS_PUBKEYTYPE, the most
|
|
// important property this function is designed to test for.
|
|
static_assert(STANDARD_SCRIPT_VERIFY_FLAGS & SCRIPT_VERIFY_WITNESS_PUBKEYTYPE, "IsSolvable requires standard script flags to include WITNESS_PUBKEYTYPE");
|
|
if (ProduceSignature(provider, DUMMY_SIGNATURE_CREATOR, script, sigs)) {
|
|
// VerifyScript check is just defensive, and should never fail.
|
|
bool verified = VerifyScript(sigs.scriptSig, script, &sigs.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, DUMMY_CHECKER);
|
|
assert(verified);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool IsSegWitOutput(const SigningProvider& provider, const CScript& script)
|
|
{
|
|
int version;
|
|
valtype program;
|
|
if (script.IsWitnessProgram(version, program)) return true;
|
|
if (script.IsPayToScriptHash()) {
|
|
std::vector<valtype> solutions;
|
|
auto whichtype = Solver(script, solutions);
|
|
if (whichtype == TxoutType::SCRIPTHASH) {
|
|
auto h160 = uint160(solutions[0]);
|
|
CScript subscript;
|
|
if (provider.GetCScript(CScriptID{h160}, subscript)) {
|
|
if (subscript.IsWitnessProgram(version, program)) return true;
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool SignTransaction(CMutableTransaction& mtx, const SigningProvider* keystore, const std::map<COutPoint, Coin>& coins, int nHashType, std::map<int, bilingual_str>& input_errors)
|
|
{
|
|
bool fHashSingle = ((nHashType & ~SIGHASH_ANYONECANPAY) == SIGHASH_SINGLE);
|
|
|
|
// Use CTransaction for the constant parts of the
|
|
// transaction to avoid rehashing.
|
|
const CTransaction txConst(mtx);
|
|
|
|
PrecomputedTransactionData txdata;
|
|
std::vector<CTxOut> spent_outputs;
|
|
for (unsigned int i = 0; i < mtx.vin.size(); ++i) {
|
|
CTxIn& txin = mtx.vin[i];
|
|
auto coin = coins.find(txin.prevout);
|
|
if (coin == coins.end() || coin->second.IsSpent()) {
|
|
txdata.Init(txConst, /* spent_outputs */ {}, /* force */ true);
|
|
break;
|
|
} else {
|
|
spent_outputs.emplace_back(coin->second.out.nValue, coin->second.out.scriptPubKey);
|
|
}
|
|
}
|
|
if (spent_outputs.size() == mtx.vin.size()) {
|
|
txdata.Init(txConst, std::move(spent_outputs), true);
|
|
}
|
|
|
|
// Sign what we can:
|
|
for (unsigned int i = 0; i < mtx.vin.size(); ++i) {
|
|
CTxIn& txin = mtx.vin[i];
|
|
auto coin = coins.find(txin.prevout);
|
|
if (coin == coins.end() || coin->second.IsSpent()) {
|
|
input_errors[i] = _("Input not found or already spent");
|
|
continue;
|
|
}
|
|
const CScript& prevPubKey = coin->second.out.scriptPubKey;
|
|
const CAmount& amount = coin->second.out.nValue;
|
|
|
|
SignatureData sigdata = DataFromTransaction(mtx, i, coin->second.out);
|
|
// Only sign SIGHASH_SINGLE if there's a corresponding output:
|
|
if (!fHashSingle || (i < mtx.vout.size())) {
|
|
ProduceSignature(*keystore, MutableTransactionSignatureCreator(&mtx, i, amount, &txdata, nHashType), prevPubKey, sigdata);
|
|
}
|
|
|
|
UpdateInput(txin, sigdata);
|
|
|
|
// amount must be specified for valid segwit signature
|
|
if (amount == MAX_MONEY && !txin.scriptWitness.IsNull()) {
|
|
input_errors[i] = _("Missing amount");
|
|
continue;
|
|
}
|
|
|
|
ScriptError serror = SCRIPT_ERR_OK;
|
|
if (!VerifyScript(txin.scriptSig, prevPubKey, &txin.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, TransactionSignatureChecker(&txConst, i, amount, txdata, MissingDataBehavior::FAIL), &serror)) {
|
|
if (serror == SCRIPT_ERR_INVALID_STACK_OPERATION) {
|
|
// Unable to sign input and verification failed (possible attempt to partially sign).
|
|
input_errors[i] = Untranslated("Unable to sign input, invalid stack size (possibly missing key)");
|
|
} else if (serror == SCRIPT_ERR_SIG_NULLFAIL) {
|
|
// Verification failed (possibly due to insufficient signatures).
|
|
input_errors[i] = Untranslated("CHECK(MULTI)SIG failing with non-zero signature (possibly need more signatures)");
|
|
} else {
|
|
input_errors[i] = Untranslated(ScriptErrorString(serror));
|
|
}
|
|
} else {
|
|
// If this input succeeds, make sure there is no error set for it
|
|
input_errors.erase(i);
|
|
}
|
|
}
|
|
return input_errors.empty();
|
|
}
|