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Diffstat (limited to 'src/psbt.cpp')
| -rw-r--r-- | src/psbt.cpp | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/src/psbt.cpp b/src/psbt.cpp new file mode 100644 index 0000000000..f31f2af0d1 --- /dev/null +++ b/src/psbt.cpp @@ -0,0 +1,368 @@ +// Copyright (c) 2009-2018 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 <coins.h> +#include <consensus/tx_verify.h> +#include <policy/policy.h> +#include <psbt.h> +#include <util/strencodings.h> + +#include <numeric> + +PartiallySignedTransaction::PartiallySignedTransaction(const CMutableTransaction& tx) : tx(tx) +{ + inputs.resize(tx.vin.size()); + outputs.resize(tx.vout.size()); +} + +bool PartiallySignedTransaction::IsNull() const +{ + return !tx && inputs.empty() && outputs.empty() && unknown.empty(); +} + +bool PartiallySignedTransaction::Merge(const PartiallySignedTransaction& psbt) +{ + // Prohibited to merge two PSBTs over different transactions + if (tx->GetHash() != psbt.tx->GetHash()) { + return false; + } + + for (unsigned int i = 0; i < inputs.size(); ++i) { + inputs[i].Merge(psbt.inputs[i]); + } + for (unsigned int i = 0; i < outputs.size(); ++i) { + outputs[i].Merge(psbt.outputs[i]); + } + unknown.insert(psbt.unknown.begin(), psbt.unknown.end()); + + return true; +} + +bool PartiallySignedTransaction::IsSane() const +{ + for (PSBTInput input : inputs) { + if (!input.IsSane()) return false; + } + return true; +} + +bool PartiallySignedTransaction::AddInput(const CTxIn& txin, PSBTInput& psbtin) +{ + if (std::find(tx->vin.begin(), tx->vin.end(), txin) != tx->vin.end()) { + return false; + } + tx->vin.push_back(txin); + psbtin.partial_sigs.clear(); + psbtin.final_script_sig.clear(); + psbtin.final_script_witness.SetNull(); + inputs.push_back(psbtin); + return true; +} + +bool PartiallySignedTransaction::AddOutput(const CTxOut& txout, const PSBTOutput& psbtout) +{ + tx->vout.push_back(txout); + outputs.push_back(psbtout); + return true; +} + +bool PartiallySignedTransaction::GetInputUTXO(CTxOut& utxo, int input_index) const +{ + PSBTInput input = inputs[input_index]; + int prevout_index = tx->vin[input_index].prevout.n; + if (input.non_witness_utxo) { + utxo = input.non_witness_utxo->vout[prevout_index]; + } else if (!input.witness_utxo.IsNull()) { + utxo = input.witness_utxo; + } else { + return false; + } + return true; +} + +bool PSBTInput::IsNull() const +{ + return !non_witness_utxo && witness_utxo.IsNull() && partial_sigs.empty() && unknown.empty() && hd_keypaths.empty() && redeem_script.empty() && witness_script.empty(); +} + +void PSBTInput::FillSignatureData(SignatureData& sigdata) const +{ + if (!final_script_sig.empty()) { + sigdata.scriptSig = final_script_sig; + sigdata.complete = true; + } + if (!final_script_witness.IsNull()) { + sigdata.scriptWitness = final_script_witness; + sigdata.complete = true; + } + if (sigdata.complete) { + return; + } + + sigdata.signatures.insert(partial_sigs.begin(), partial_sigs.end()); + if (!redeem_script.empty()) { + sigdata.redeem_script = redeem_script; + } + if (!witness_script.empty()) { + sigdata.witness_script = witness_script; + } + for (const auto& key_pair : hd_keypaths) { + sigdata.misc_pubkeys.emplace(key_pair.first.GetID(), key_pair); + } +} + +void PSBTInput::FromSignatureData(const SignatureData& sigdata) +{ + if (sigdata.complete) { + partial_sigs.clear(); + hd_keypaths.clear(); + redeem_script.clear(); + witness_script.clear(); + + if (!sigdata.scriptSig.empty()) { + final_script_sig = sigdata.scriptSig; + } + if (!sigdata.scriptWitness.IsNull()) { + final_script_witness = sigdata.scriptWitness; + } + return; + } + + partial_sigs.insert(sigdata.signatures.begin(), sigdata.signatures.end()); + 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; + } + for (const auto& entry : sigdata.misc_pubkeys) { + hd_keypaths.emplace(entry.second); + } +} + +void PSBTInput::Merge(const PSBTInput& input) +{ + if (!non_witness_utxo && input.non_witness_utxo) non_witness_utxo = input.non_witness_utxo; + if (witness_utxo.IsNull() && !input.witness_utxo.IsNull()) { + witness_utxo = input.witness_utxo; + non_witness_utxo = nullptr; // Clear out any non-witness utxo when we set a witness one. + } + + partial_sigs.insert(input.partial_sigs.begin(), input.partial_sigs.end()); + hd_keypaths.insert(input.hd_keypaths.begin(), input.hd_keypaths.end()); + unknown.insert(input.unknown.begin(), input.unknown.end()); + + if (redeem_script.empty() && !input.redeem_script.empty()) redeem_script = input.redeem_script; + if (witness_script.empty() && !input.witness_script.empty()) witness_script = input.witness_script; + if (final_script_sig.empty() && !input.final_script_sig.empty()) final_script_sig = input.final_script_sig; + if (final_script_witness.IsNull() && !input.final_script_witness.IsNull()) final_script_witness = input.final_script_witness; +} + +bool PSBTInput::IsSane() const +{ + // Cannot have both witness and non-witness utxos + if (!witness_utxo.IsNull() && non_witness_utxo) return false; + + // If we have a witness_script or a scriptWitness, we must also have a witness utxo + if (!witness_script.empty() && witness_utxo.IsNull()) return false; + if (!final_script_witness.IsNull() && witness_utxo.IsNull()) return false; + + return true; +} + +void PSBTOutput::FillSignatureData(SignatureData& sigdata) const +{ + if (!redeem_script.empty()) { + sigdata.redeem_script = redeem_script; + } + if (!witness_script.empty()) { + sigdata.witness_script = witness_script; + } + for (const auto& key_pair : hd_keypaths) { + sigdata.misc_pubkeys.emplace(key_pair.first.GetID(), key_pair); + } +} + +void PSBTOutput::FromSignatureData(const SignatureData& sigdata) +{ + 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; + } + for (const auto& entry : sigdata.misc_pubkeys) { + hd_keypaths.emplace(entry.second); + } +} + +bool PSBTOutput::IsNull() const +{ + return redeem_script.empty() && witness_script.empty() && hd_keypaths.empty() && unknown.empty(); +} + +void PSBTOutput::Merge(const PSBTOutput& output) +{ + hd_keypaths.insert(output.hd_keypaths.begin(), output.hd_keypaths.end()); + unknown.insert(output.unknown.begin(), output.unknown.end()); + + if (redeem_script.empty() && !output.redeem_script.empty()) redeem_script = output.redeem_script; + if (witness_script.empty() && !output.witness_script.empty()) witness_script = output.witness_script; +} +bool PSBTInputSigned(const PSBTInput& input) +{ + return !input.final_script_sig.empty() || !input.final_script_witness.IsNull(); +} + +bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction& psbt, int index, int sighash, SignatureData* out_sigdata, bool use_dummy) +{ + PSBTInput& input = psbt.inputs.at(index); + const CMutableTransaction& tx = *psbt.tx; + + if (PSBTInputSigned(input)) { + return true; + } + + // Fill SignatureData with input info + SignatureData sigdata; + input.FillSignatureData(sigdata); + + // Get UTXO + bool require_witness_sig = false; + CTxOut utxo; + + // Verify input sanity, which checks that at most one of witness or non-witness utxos is provided. + if (!input.IsSane()) { + return false; + } + + if (input.non_witness_utxo) { + // If we're taking our information from a non-witness UTXO, verify that it matches the prevout. + COutPoint prevout = tx.vin[index].prevout; + if (input.non_witness_utxo->GetHash() != prevout.hash) { + return false; + } + utxo = input.non_witness_utxo->vout[prevout.n]; + } else if (!input.witness_utxo.IsNull()) { + utxo = input.witness_utxo; + // When we're taking our information from a witness UTXO, we can't verify it is actually data from + // the output being spent. This is safe in case a witness signature is produced (which includes this + // information directly in the hash), but not for non-witness signatures. Remember that we require + // a witness signature in this situation. + require_witness_sig = true; + } else { + return false; + } + + sigdata.witness = false; + bool sig_complete; + if (use_dummy) { + sig_complete = ProduceSignature(provider, DUMMY_SIGNATURE_CREATOR, utxo.scriptPubKey, sigdata); + } else { + MutableTransactionSignatureCreator creator(&tx, index, utxo.nValue, sighash); + sig_complete = ProduceSignature(provider, creator, utxo.scriptPubKey, sigdata); + } + // Verify that a witness signature was produced in case one was required. + if (require_witness_sig && !sigdata.witness) return false; + input.FromSignatureData(sigdata); + + // If we have a witness signature, use the smaller witness UTXO. + if (sigdata.witness) { + input.witness_utxo = utxo; + input.non_witness_utxo = nullptr; + } + + // Fill in the missing info + if (out_sigdata) { + out_sigdata->missing_pubkeys = sigdata.missing_pubkeys; + out_sigdata->missing_sigs = sigdata.missing_sigs; + out_sigdata->missing_redeem_script = sigdata.missing_redeem_script; + out_sigdata->missing_witness_script = sigdata.missing_witness_script; + } + + return sig_complete; +} + +bool FinalizePSBT(PartiallySignedTransaction& psbtx) +{ + // Finalize input signatures -- in case we have partial signatures that add up to a complete + // signature, but have not combined them yet (e.g. because the combiner that created this + // PartiallySignedTransaction did not understand them), this will combine them into a final + // script. + bool complete = true; + for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) { + complete &= SignPSBTInput(DUMMY_SIGNING_PROVIDER, psbtx, i, SIGHASH_ALL); + } + + return complete; +} + +bool FinalizeAndExtractPSBT(PartiallySignedTransaction& psbtx, CMutableTransaction& result) +{ + // It's not safe to extract a PSBT that isn't finalized, and there's no easy way to check + // whether a PSBT is finalized without finalizing it, so we just do this. + if (!FinalizePSBT(psbtx)) { + return false; + } + + result = *psbtx.tx; + for (unsigned int i = 0; i < result.vin.size(); ++i) { + result.vin[i].scriptSig = psbtx.inputs[i].final_script_sig; + result.vin[i].scriptWitness = psbtx.inputs[i].final_script_witness; + } + return true; +} + +TransactionError CombinePSBTs(PartiallySignedTransaction& out, const std::vector<PartiallySignedTransaction>& psbtxs) +{ + out = psbtxs[0]; // Copy the first one + + // Merge + for (auto it = std::next(psbtxs.begin()); it != psbtxs.end(); ++it) { + if (!out.Merge(*it)) { + return TransactionError::PSBT_MISMATCH; + } + } + if (!out.IsSane()) { + return TransactionError::INVALID_PSBT; + } + + return TransactionError::OK; +} + +std::string PSBTRoleName(PSBTRole role) { + switch (role) { + case PSBTRole::UPDATER: return "updater"; + case PSBTRole::SIGNER: return "signer"; + case PSBTRole::FINALIZER: return "finalizer"; + case PSBTRole::EXTRACTOR: return "extractor"; + } +} + +bool DecodeBase64PSBT(PartiallySignedTransaction& psbt, const std::string& base64_tx, std::string& error) +{ + bool invalid; + std::string tx_data = DecodeBase64(base64_tx, &invalid); + if (invalid) { + error = "invalid base64"; + return false; + } + return DecodeRawPSBT(psbt, tx_data, error); +} + +bool DecodeRawPSBT(PartiallySignedTransaction& psbt, const std::string& tx_data, std::string& error) +{ + CDataStream ss_data(tx_data.data(), tx_data.data() + tx_data.size(), SER_NETWORK, PROTOCOL_VERSION); + try { + ss_data >> psbt; + if (!ss_data.empty()) { + error = "extra data after PSBT"; + return false; + } + } catch (const std::exception& e) { + error = e.what(); + return false; + } + return true; +} |