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Diffstat (limited to 'src/psbt.h')
| -rw-r--r-- | src/psbt.h | 574 |
1 files changed, 574 insertions, 0 deletions
diff --git a/src/psbt.h b/src/psbt.h new file mode 100644 index 0000000000..e18790322b --- /dev/null +++ b/src/psbt.h @@ -0,0 +1,574 @@ +// 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. + +#ifndef BITCOIN_PSBT_H +#define BITCOIN_PSBT_H + +#include <attributes.h> +#include <node/transaction.h> +#include <primitives/transaction.h> +#include <pubkey.h> +#include <script/sign.h> + +// Magic bytes +static constexpr uint8_t PSBT_MAGIC_BYTES[5] = {'p', 's', 'b', 't', 0xff}; + +// Global types +static constexpr uint8_t PSBT_GLOBAL_UNSIGNED_TX = 0x00; + +// Input types +static constexpr uint8_t PSBT_IN_NON_WITNESS_UTXO = 0x00; +static constexpr uint8_t PSBT_IN_WITNESS_UTXO = 0x01; +static constexpr uint8_t PSBT_IN_PARTIAL_SIG = 0x02; +static constexpr uint8_t PSBT_IN_SIGHASH = 0x03; +static constexpr uint8_t PSBT_IN_REDEEMSCRIPT = 0x04; +static constexpr uint8_t PSBT_IN_WITNESSSCRIPT = 0x05; +static constexpr uint8_t PSBT_IN_BIP32_DERIVATION = 0x06; +static constexpr uint8_t PSBT_IN_SCRIPTSIG = 0x07; +static constexpr uint8_t PSBT_IN_SCRIPTWITNESS = 0x08; + +// Output types +static constexpr uint8_t PSBT_OUT_REDEEMSCRIPT = 0x00; +static constexpr uint8_t PSBT_OUT_WITNESSSCRIPT = 0x01; +static constexpr uint8_t PSBT_OUT_BIP32_DERIVATION = 0x02; + +// The separator is 0x00. Reading this in means that the unserializer can interpret it +// as a 0 length key which indicates that this is the separator. The separator has no value. +static constexpr uint8_t PSBT_SEPARATOR = 0x00; + +/** A structure for PSBTs which contain per-input information */ +struct PSBTInput +{ + CTransactionRef non_witness_utxo; + CTxOut witness_utxo; + CScript redeem_script; + CScript witness_script; + CScript final_script_sig; + CScriptWitness final_script_witness; + std::map<CPubKey, KeyOriginInfo> hd_keypaths; + std::map<CKeyID, SigPair> partial_sigs; + std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown; + int sighash_type = 0; + + bool IsNull() const; + void FillSignatureData(SignatureData& sigdata) const; + void FromSignatureData(const SignatureData& sigdata); + void Merge(const PSBTInput& input); + bool IsSane() const; + PSBTInput() {} + + template <typename Stream> + inline void Serialize(Stream& s) const { + // Write the utxo + // If there is a non-witness utxo, then don't add the witness one. + if (non_witness_utxo) { + SerializeToVector(s, PSBT_IN_NON_WITNESS_UTXO); + OverrideStream<Stream> os(&s, s.GetType(), s.GetVersion() | SERIALIZE_TRANSACTION_NO_WITNESS); + SerializeToVector(os, non_witness_utxo); + } else if (!witness_utxo.IsNull()) { + SerializeToVector(s, PSBT_IN_WITNESS_UTXO); + SerializeToVector(s, witness_utxo); + } + + if (final_script_sig.empty() && final_script_witness.IsNull()) { + // Write any partial signatures + for (auto sig_pair : partial_sigs) { + SerializeToVector(s, PSBT_IN_PARTIAL_SIG, MakeSpan(sig_pair.second.first)); + s << sig_pair.second.second; + } + + // Write the sighash type + if (sighash_type > 0) { + SerializeToVector(s, PSBT_IN_SIGHASH); + SerializeToVector(s, sighash_type); + } + + // Write the redeem script + if (!redeem_script.empty()) { + SerializeToVector(s, PSBT_IN_REDEEMSCRIPT); + s << redeem_script; + } + + // Write the witness script + if (!witness_script.empty()) { + SerializeToVector(s, PSBT_IN_WITNESSSCRIPT); + s << witness_script; + } + + // Write any hd keypaths + SerializeHDKeypaths(s, hd_keypaths, PSBT_IN_BIP32_DERIVATION); + } + + // Write script sig + if (!final_script_sig.empty()) { + SerializeToVector(s, PSBT_IN_SCRIPTSIG); + s << final_script_sig; + } + // write script witness + if (!final_script_witness.IsNull()) { + SerializeToVector(s, PSBT_IN_SCRIPTWITNESS); + SerializeToVector(s, final_script_witness.stack); + } + + // Write unknown things + for (auto& entry : unknown) { + s << entry.first; + s << entry.second; + } + + s << PSBT_SEPARATOR; + } + + + template <typename Stream> + inline void Unserialize(Stream& s) { + // Read loop + bool found_sep = false; + while(!s.empty()) { + // Read + std::vector<unsigned char> key; + s >> key; + + // the key is empty if that was actually a separator byte + // This is a special case for key lengths 0 as those are not allowed (except for separator) + if (key.empty()) { + found_sep = true; + break; + } + + // First byte of key is the type + unsigned char type = key[0]; + + // Do stuff based on type + switch(type) { + case PSBT_IN_NON_WITNESS_UTXO: + { + if (non_witness_utxo) { + throw std::ios_base::failure("Duplicate Key, input non-witness utxo already provided"); + } else if (key.size() != 1) { + throw std::ios_base::failure("Non-witness utxo key is more than one byte type"); + } + // Set the stream to unserialize with witness since this is always a valid network transaction + OverrideStream<Stream> os(&s, s.GetType(), s.GetVersion() & ~SERIALIZE_TRANSACTION_NO_WITNESS); + UnserializeFromVector(os, non_witness_utxo); + break; + } + case PSBT_IN_WITNESS_UTXO: + if (!witness_utxo.IsNull()) { + throw std::ios_base::failure("Duplicate Key, input witness utxo already provided"); + } else if (key.size() != 1) { + throw std::ios_base::failure("Witness utxo key is more than one byte type"); + } + UnserializeFromVector(s, witness_utxo); + break; + case PSBT_IN_PARTIAL_SIG: + { + // Make sure that the key is the size of pubkey + 1 + if (key.size() != CPubKey::PUBLIC_KEY_SIZE + 1 && key.size() != CPubKey::COMPRESSED_PUBLIC_KEY_SIZE + 1) { + throw std::ios_base::failure("Size of key was not the expected size for the type partial signature pubkey"); + } + // Read in the pubkey from key + CPubKey pubkey(key.begin() + 1, key.end()); + if (!pubkey.IsFullyValid()) { + throw std::ios_base::failure("Invalid pubkey"); + } + if (partial_sigs.count(pubkey.GetID()) > 0) { + throw std::ios_base::failure("Duplicate Key, input partial signature for pubkey already provided"); + } + + // Read in the signature from value + std::vector<unsigned char> sig; + s >> sig; + + // Add to list + partial_sigs.emplace(pubkey.GetID(), SigPair(pubkey, std::move(sig))); + break; + } + case PSBT_IN_SIGHASH: + if (sighash_type > 0) { + throw std::ios_base::failure("Duplicate Key, input sighash type already provided"); + } else if (key.size() != 1) { + throw std::ios_base::failure("Sighash type key is more than one byte type"); + } + UnserializeFromVector(s, sighash_type); + break; + case PSBT_IN_REDEEMSCRIPT: + { + if (!redeem_script.empty()) { + throw std::ios_base::failure("Duplicate Key, input redeemScript already provided"); + } else if (key.size() != 1) { + throw std::ios_base::failure("Input redeemScript key is more than one byte type"); + } + s >> redeem_script; + break; + } + case PSBT_IN_WITNESSSCRIPT: + { + if (!witness_script.empty()) { + throw std::ios_base::failure("Duplicate Key, input witnessScript already provided"); + } else if (key.size() != 1) { + throw std::ios_base::failure("Input witnessScript key is more than one byte type"); + } + s >> witness_script; + break; + } + case PSBT_IN_BIP32_DERIVATION: + { + DeserializeHDKeypaths(s, key, hd_keypaths); + break; + } + case PSBT_IN_SCRIPTSIG: + { + if (!final_script_sig.empty()) { + throw std::ios_base::failure("Duplicate Key, input final scriptSig already provided"); + } else if (key.size() != 1) { + throw std::ios_base::failure("Final scriptSig key is more than one byte type"); + } + s >> final_script_sig; + break; + } + case PSBT_IN_SCRIPTWITNESS: + { + if (!final_script_witness.IsNull()) { + throw std::ios_base::failure("Duplicate Key, input final scriptWitness already provided"); + } else if (key.size() != 1) { + throw std::ios_base::failure("Final scriptWitness key is more than one byte type"); + } + UnserializeFromVector(s, final_script_witness.stack); + break; + } + // Unknown stuff + default: + if (unknown.count(key) > 0) { + throw std::ios_base::failure("Duplicate Key, key for unknown value already provided"); + } + // Read in the value + std::vector<unsigned char> val_bytes; + s >> val_bytes; + unknown.emplace(std::move(key), std::move(val_bytes)); + break; + } + } + + if (!found_sep) { + throw std::ios_base::failure("Separator is missing at the end of an input map"); + } + } + + template <typename Stream> + PSBTInput(deserialize_type, Stream& s) { + Unserialize(s); + } +}; + +/** A structure for PSBTs which contains per output information */ +struct PSBTOutput +{ + CScript redeem_script; + CScript witness_script; + std::map<CPubKey, KeyOriginInfo> hd_keypaths; + std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown; + + bool IsNull() const; + void FillSignatureData(SignatureData& sigdata) const; + void FromSignatureData(const SignatureData& sigdata); + void Merge(const PSBTOutput& output); + bool IsSane() const; + PSBTOutput() {} + + template <typename Stream> + inline void Serialize(Stream& s) const { + // Write the redeem script + if (!redeem_script.empty()) { + SerializeToVector(s, PSBT_OUT_REDEEMSCRIPT); + s << redeem_script; + } + + // Write the witness script + if (!witness_script.empty()) { + SerializeToVector(s, PSBT_OUT_WITNESSSCRIPT); + s << witness_script; + } + + // Write any hd keypaths + SerializeHDKeypaths(s, hd_keypaths, PSBT_OUT_BIP32_DERIVATION); + + // Write unknown things + for (auto& entry : unknown) { + s << entry.first; + s << entry.second; + } + + s << PSBT_SEPARATOR; + } + + + template <typename Stream> + inline void Unserialize(Stream& s) { + // Read loop + bool found_sep = false; + while(!s.empty()) { + // Read + std::vector<unsigned char> key; + s >> key; + + // the key is empty if that was actually a separator byte + // This is a special case for key lengths 0 as those are not allowed (except for separator) + if (key.empty()) { + found_sep = true; + break; + } + + // First byte of key is the type + unsigned char type = key[0]; + + // Do stuff based on type + switch(type) { + case PSBT_OUT_REDEEMSCRIPT: + { + if (!redeem_script.empty()) { + throw std::ios_base::failure("Duplicate Key, output redeemScript already provided"); + } else if (key.size() != 1) { + throw std::ios_base::failure("Output redeemScript key is more than one byte type"); + } + s >> redeem_script; + break; + } + case PSBT_OUT_WITNESSSCRIPT: + { + if (!witness_script.empty()) { + throw std::ios_base::failure("Duplicate Key, output witnessScript already provided"); + } else if (key.size() != 1) { + throw std::ios_base::failure("Output witnessScript key is more than one byte type"); + } + s >> witness_script; + break; + } + case PSBT_OUT_BIP32_DERIVATION: + { + DeserializeHDKeypaths(s, key, hd_keypaths); + break; + } + // Unknown stuff + default: { + if (unknown.count(key) > 0) { + throw std::ios_base::failure("Duplicate Key, key for unknown value already provided"); + } + // Read in the value + std::vector<unsigned char> val_bytes; + s >> val_bytes; + unknown.emplace(std::move(key), std::move(val_bytes)); + break; + } + } + } + + if (!found_sep) { + throw std::ios_base::failure("Separator is missing at the end of an output map"); + } + } + + template <typename Stream> + PSBTOutput(deserialize_type, Stream& s) { + Unserialize(s); + } +}; + +/** A version of CTransaction with the PSBT format*/ +struct PartiallySignedTransaction +{ + boost::optional<CMutableTransaction> tx; + std::vector<PSBTInput> inputs; + std::vector<PSBTOutput> outputs; + std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown; + + bool IsNull() const; + + /** Merge psbt into this. The two psbts must have the same underlying CTransaction (i.e. the + * same actual Bitcoin transaction.) Returns true if the merge succeeded, false otherwise. */ + NODISCARD bool Merge(const PartiallySignedTransaction& psbt); + bool IsSane() const; + PartiallySignedTransaction() {} + PartiallySignedTransaction(const PartiallySignedTransaction& psbt_in) : tx(psbt_in.tx), inputs(psbt_in.inputs), outputs(psbt_in.outputs), unknown(psbt_in.unknown) {} + explicit PartiallySignedTransaction(const CMutableTransaction& tx); + + template <typename Stream> + inline void Serialize(Stream& s) const { + + // magic bytes + s << PSBT_MAGIC_BYTES; + + // unsigned tx flag + SerializeToVector(s, PSBT_GLOBAL_UNSIGNED_TX); + + // Write serialized tx to a stream + OverrideStream<Stream> os(&s, s.GetType(), s.GetVersion() | SERIALIZE_TRANSACTION_NO_WITNESS); + SerializeToVector(os, *tx); + + // Write the unknown things + for (auto& entry : unknown) { + s << entry.first; + s << entry.second; + } + + // Separator + s << PSBT_SEPARATOR; + + // Write inputs + for (const PSBTInput& input : inputs) { + s << input; + } + // Write outputs + for (const PSBTOutput& output : outputs) { + s << output; + } + } + + + template <typename Stream> + inline void Unserialize(Stream& s) { + // Read the magic bytes + uint8_t magic[5]; + s >> magic; + if (!std::equal(magic, magic + 5, PSBT_MAGIC_BYTES)) { + throw std::ios_base::failure("Invalid PSBT magic bytes"); + } + + // Read global data + bool found_sep = false; + while(!s.empty()) { + // Read + std::vector<unsigned char> key; + s >> key; + + // the key is empty if that was actually a separator byte + // This is a special case for key lengths 0 as those are not allowed (except for separator) + if (key.empty()) { + found_sep = true; + break; + } + + // First byte of key is the type + unsigned char type = key[0]; + + // Do stuff based on type + switch(type) { + case PSBT_GLOBAL_UNSIGNED_TX: + { + if (tx) { + throw std::ios_base::failure("Duplicate Key, unsigned tx already provided"); + } else if (key.size() != 1) { + throw std::ios_base::failure("Global unsigned tx key is more than one byte type"); + } + CMutableTransaction mtx; + // Set the stream to serialize with non-witness since this should always be non-witness + OverrideStream<Stream> os(&s, s.GetType(), s.GetVersion() | SERIALIZE_TRANSACTION_NO_WITNESS); + UnserializeFromVector(os, mtx); + tx = std::move(mtx); + // Make sure that all scriptSigs and scriptWitnesses are empty + for (const CTxIn& txin : tx->vin) { + if (!txin.scriptSig.empty() || !txin.scriptWitness.IsNull()) { + throw std::ios_base::failure("Unsigned tx does not have empty scriptSigs and scriptWitnesses."); + } + } + break; + } + // Unknown stuff + default: { + if (unknown.count(key) > 0) { + throw std::ios_base::failure("Duplicate Key, key for unknown value already provided"); + } + // Read in the value + std::vector<unsigned char> val_bytes; + s >> val_bytes; + unknown.emplace(std::move(key), std::move(val_bytes)); + } + } + } + + if (!found_sep) { + throw std::ios_base::failure("Separator is missing at the end of the global map"); + } + + // Make sure that we got an unsigned tx + if (!tx) { + throw std::ios_base::failure("No unsigned transcation was provided"); + } + + // Read input data + unsigned int i = 0; + while (!s.empty() && i < tx->vin.size()) { + PSBTInput input; + s >> input; + inputs.push_back(input); + + // Make sure the non-witness utxo matches the outpoint + if (input.non_witness_utxo && input.non_witness_utxo->GetHash() != tx->vin[i].prevout.hash) { + throw std::ios_base::failure("Non-witness UTXO does not match outpoint hash"); + } + ++i; + } + // Make sure that the number of inputs matches the number of inputs in the transaction + if (inputs.size() != tx->vin.size()) { + throw std::ios_base::failure("Inputs provided does not match the number of inputs in transaction."); + } + + // Read output data + i = 0; + while (!s.empty() && i < tx->vout.size()) { + PSBTOutput output; + s >> output; + outputs.push_back(output); + ++i; + } + // Make sure that the number of outputs matches the number of outputs in the transaction + if (outputs.size() != tx->vout.size()) { + throw std::ios_base::failure("Outputs provided does not match the number of outputs in transaction."); + } + // Sanity check + if (!IsSane()) { + throw std::ios_base::failure("PSBT is not sane."); + } + } + + template <typename Stream> + PartiallySignedTransaction(deserialize_type, Stream& s) { + Unserialize(s); + } +}; + +/** Checks whether a PSBTInput is already signed. */ +bool PSBTInputSigned(PSBTInput& input); + +/** Signs a PSBTInput, verifying that all provided data matches what is being signed. */ +bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction& psbt, int index, int sighash = SIGHASH_ALL); + +/** + * Finalizes a PSBT if possible, combining partial signatures. + * + * @param[in,out] &psbtx reference to PartiallySignedTransaction to finalize + * return True if the PSBT is now complete, false otherwise + */ +bool FinalizePSBT(PartiallySignedTransaction& psbtx); + +/** + * Finalizes a PSBT if possible, and extracts it to a CMutableTransaction if it could be finalized. + * + * @param[in] &psbtx reference to PartiallySignedTransaction + * @param[out] result CMutableTransaction representing the complete transaction, if successful + * @return True if we successfully extracted the transaction, false otherwise + */ +bool FinalizeAndExtractPSBT(PartiallySignedTransaction& psbtx, CMutableTransaction& result); + +/** + * Combines PSBTs with the same underlying transaction, resulting in a single PSBT with all partial signatures from each input. + * + * @param[out] &out the combined PSBT, if successful + * @param[out] &error reference to TransactionError to fill with error info on failure + * @param[in] psbtxs the PSBTs to combine + * @return True if we successfully combined the transactions, false if they were not compatible + */ +bool CombinePSBTs(PartiallySignedTransaction& out, TransactionError& error, const std::vector<PartiallySignedTransaction>& psbtxs); + +#endif // BITCOIN_PSBT_H |