From 2a3a873524dc97a7f73e3f2c9e5d4dc94517067b Mon Sep 17 00:00:00 2001 From: Kittywhiskers Van Gogh <63189531+kittywhiskers@users.noreply.github.com> Date: Tue, 20 Sep 2022 13:56:17 +0530 Subject: [PATCH] partial bitcoin#13932: Additional utility RPCs for PSBT Contains cb40b3abd4514361a024a1e7a1a281da9261261b and 540729ef4bf1b6c6da1ec795e441d2ce56a9a58b Verbatim for release notes borrowed from https://raw.githubusercontent.com/bitcoin/bitcoin/master/doc/release-notes/release-notes-0.18.0.md --- doc/release-notes-5017.md | 15 +++ src/psbt.cpp | 20 +++- src/psbt.h | 2 +- src/rpc/rawtransaction.cpp | 192 ++++++++++++++++++++++++++++++++++++ test/functional/rpc_psbt.py | 22 +++++ 5 files changed, 246 insertions(+), 5 deletions(-) create mode 100644 doc/release-notes-5017.md diff --git a/doc/release-notes-5017.md b/doc/release-notes-5017.md new file mode 100644 index 0000000000..1955028b59 --- /dev/null +++ b/doc/release-notes-5017.md @@ -0,0 +1,15 @@ +New RPCs +-------- + +- `analyzepsbt` examines a PSBT and provides information about what + the PSBT contains and the next steps that need to be taken in order + to complete the transaction. For each input of a PSBT, `analyzepsbt` + provides information about what information is missing for that + input, including whether a UTXO needs to be provided, what pubkeys + still need to be provided, which scripts need to be provided, and + what signatures are still needed. Every input will also list which + role is needed to complete that input, and `analyzepsbt` will also + list the next role in general needed to complete the PSBT. + `analyzepsbt` will also provide the estimated fee rate and estimated + virtual size of the completed transaction if it has enough + information to do so. diff --git a/src/psbt.cpp b/src/psbt.cpp index 0fa7ef2d5a..696084c952 100644 --- a/src/psbt.cpp +++ b/src/psbt.cpp @@ -189,13 +189,12 @@ void UpdatePSBTOutput(const SigningProvider& provider, PartiallySignedTransactio // Put redeem_script, key paths, into PSBTOutput. psbt_out.FromSignatureData(sigdata); } - bool PSBTInputSigned(PSBTInput& input) { return !input.final_script_sig.empty(); } -bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction& psbt, int index, int sighash) +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; @@ -227,9 +226,22 @@ bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction& return false; } - MutableTransactionSignatureCreator creator(&tx, index, utxo.nValue, sighash); - bool sig_complete = ProduceSignature(provider, creator, utxo.scriptPubKey, sigdata); + 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); + } input.FromSignatureData(sigdata); + + // 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; + } + return sig_complete; } diff --git a/src/psbt.h b/src/psbt.h index c868e1f15f..e0b1cdfc05 100644 --- a/src/psbt.h +++ b/src/psbt.h @@ -488,7 +488,7 @@ struct PartiallySignedTransaction 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); +bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction& psbt, int index, int sighash = SIGHASH_ALL, SignatureData* out_sigdata = nullptr, bool use_dummy = false); /** Updates a PSBTOutput with information from provider. * diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp index b46f5bd9c3..83b9b86740 100644 --- a/src/rpc/rawtransaction.cpp +++ b/src/rpc/rawtransaction.cpp @@ -1575,6 +1575,197 @@ UniValue joinpsbts(const JSONRPCRequest& request) return EncodeBase64(ssTx.str()); } +UniValue analyzepsbt(const JSONRPCRequest& request) +{ + RPCHelpMan{"analyzepsbt", + "\nAnalyzes and provides information about the current status of a PSBT and its inputs\n", + { + {"psbt", RPCArg::Type::STR, RPCArg::Optional::NO, "A base64 string of a PSBT"} + }, + RPCResult { + RPCResult::Type::OBJ, "", "", + { + {RPCResult::Type::ARR, "inputs", "", + { + {RPCResult::Type::OBJ, "", "", + { + {RPCResult::Type::BOOL, "has_utxo", "Whether a UTXO is provided"}, + {RPCResult::Type::BOOL, "is_final", "Whether the input is finalized"}, + {RPCResult::Type::OBJ, "missing", /* optional */ true, "Things that are missing that are required to complete this input", + { + {RPCResult::Type::ARR, "pubkeys", /* optional */ true, "", + { + {RPCResult::Type::STR_HEX, "keyid", "Public key ID, hash160 of the public key, of a public key whose BIP 32 derivation path is missing"}, + }}, + {RPCResult::Type::ARR, "signatures", /* optional */ true, "", + { + {RPCResult::Type::STR_HEX, "keyid", "Public key ID, hash160 of the public key, of a public key whose signature is missing"}, + }}, + {RPCResult::Type::STR_HEX, "redeemscript", /* optional */ true, "Hash160 of the redeemScript that is missing"}, + }}, + {RPCResult::Type::STR, "next", /* optional */ true, "Role of the next person that this input needs to go to"}, + }}, + }}, + {RPCResult::Type::NUM, "estimated_vsize", /* optional */ true, "Estimated vsize of the final signed transaction"}, + {RPCResult::Type::STR_AMOUNT, "estimated_feerate", /* optional */ true, "Estimated feerate of the final signed transaction in " + CURRENCY_UNIT + "/kB. Shown only if all UTXO slots in the PSBT have been filled"}, + {RPCResult::Type::STR_AMOUNT, "fee", /* optional */ true, "The transaction fee paid. Shown only if all UTXO slots in the PSBT have been filled"}, + {RPCResult::Type::STR, "next", "Role of the next person that this psbt needs to go to"}, + {RPCResult::Type::STR, "error", "Error message if there is one"}, + } + }, + RPCExamples { + HelpExampleCli("analyzepsbt", "\"psbt\"") + }}.Check(request); + + RPCTypeCheck(request.params, {UniValue::VSTR}); + + // Unserialize the transaction + PartiallySignedTransaction psbtx; + std::string error; + if (!DecodeBase64PSBT(psbtx, request.params[0].get_str(), error)) { + throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("TX decode failed %s", error)); + } + + // Go through each input and build status + UniValue result(UniValue::VOBJ); + UniValue inputs_result(UniValue::VARR); + bool calc_fee = true; + bool all_final = true; + bool only_missing_sigs = true; + bool only_missing_final = false; + CAmount in_amt = 0; + for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) { + PSBTInput& input = psbtx.inputs[i]; + UniValue input_univ(UniValue::VOBJ); + UniValue missing(UniValue::VOBJ); + + // Check for a UTXO + CTxOut utxo; + if (psbtx.GetInputUTXO(utxo, i)) { + in_amt += utxo.nValue; + input_univ.pushKV("has_utxo", true); + } else { + input_univ.pushKV("has_utxo", false); + input_univ.pushKV("is_final", false); + input_univ.pushKV("next", "updater"); + calc_fee = false; + } + + // Check if it is final + if (!utxo.IsNull() && !PSBTInputSigned(input)) { + input_univ.pushKV("is_final", false); + all_final = false; + + // Figure out what is missing + SignatureData outdata; + bool complete = SignPSBTInput(DUMMY_SIGNING_PROVIDER, psbtx, i, 1, &outdata); + + // Things are missing + if (!complete) { + if (!outdata.missing_pubkeys.empty()) { + // Missing pubkeys + UniValue missing_pubkeys_univ(UniValue::VARR); + for (const CKeyID& pubkey : outdata.missing_pubkeys) { + missing_pubkeys_univ.push_back(HexStr(pubkey)); + } + missing.pushKV("pubkeys", missing_pubkeys_univ); + } + if (!outdata.missing_redeem_script.IsNull()) { + // Missing redeemScript + missing.pushKV("redeemscript", HexStr(outdata.missing_redeem_script)); + } + if (!outdata.missing_sigs.empty()) { + // Missing sigs + UniValue missing_sigs_univ(UniValue::VARR); + for (const CKeyID& pubkey : outdata.missing_sigs) { + missing_sigs_univ.push_back(HexStr(pubkey)); + } + missing.pushKV("signatures", missing_sigs_univ); + } + input_univ.pushKV("missing", missing); + + // If we are only missing signatures and nothing else, then next is signer + if (outdata.missing_pubkeys.empty() && outdata.missing_redeem_script.IsNull() && !outdata.missing_sigs.empty()) { + input_univ.pushKV("next", "signer"); + } else { + only_missing_sigs = false; + input_univ.pushKV("next", "updater"); + } + } else { + only_missing_final = true; + input_univ.pushKV("next", "finalizer"); + } + } else if (!utxo.IsNull()){ + input_univ.pushKV("is_final", true); + } + inputs_result.push_back(input_univ); + } + result.pushKV("inputs", inputs_result); + + if (all_final) { + only_missing_sigs = false; + result.pushKV("next", "extractor"); + } + if (calc_fee) { + // Get the output amount + CAmount out_amt = std::accumulate(psbtx.tx->vout.begin(), psbtx.tx->vout.end(), 0, + [](int a, const CTxOut& b) { + return a += b.nValue; + } + ); + + // Get the fee + CAmount fee = in_amt - out_amt; + + // Estimate the size + CMutableTransaction mtx(*psbtx.tx); + CCoinsView view_dummy; + CCoinsViewCache view(&view_dummy); + bool success = true; + + for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) { + PSBTInput& input = psbtx.inputs[i]; + if (SignPSBTInput(DUMMY_SIGNING_PROVIDER, psbtx, i, 1, nullptr, true)) { + mtx.vin[i].scriptSig = input.final_script_sig; + + Coin newcoin; + if (!psbtx.GetInputUTXO(newcoin.out, i)) { + success = false; + break; + } + newcoin.nHeight = 1; + view.AddCoin(psbtx.tx->vin[i].prevout, std::move(newcoin), true); + } else { + success = false; + break; + } + } + + if (success) { + CTransaction ctx = CTransaction(mtx); + size_t size = GetVirtualTransactionSize(ctx, GetTransactionSigOpCost(ctx, view, STANDARD_SCRIPT_VERIFY_FLAGS)); + result.pushKV("estimated_vsize", (int)size); + // Estimate fee rate + CFeeRate feerate(fee, size); + result.pushKV("estimated_feerate", feerate.ToString()); + } + result.pushKV("fee", ValueFromAmount(fee)); + + if (only_missing_sigs) { + result.pushKV("next", "signer"); + } else if (only_missing_final) { + result.pushKV("next", "finalizer"); + } else if (all_final) { + result.pushKV("next", "extractor"); + } else { + result.pushKV("next", "updater"); + } + } else { + result.pushKV("next", "updater"); + } + return result; +} + // clang-format off static const CRPCCommand commands[] = { // category name actor (function) argNames @@ -1594,6 +1785,7 @@ static const CRPCCommand commands[] = { "rawtransactions", "converttopsbt", &converttopsbt, {"hexstring","permitsigdata"} }, { "rawtransactions", "utxoupdatepsbt", &utxoupdatepsbt, {"psbt"} }, { "rawtransactions", "joinpsbts", &joinpsbts, {"txs"} }, + { "rawtransactions", "analyzepsbt", &analyzepsbt, {"psbt"} }, { "blockchain", "gettxoutproof", &gettxoutproof, {"txids", "blockhash"} }, { "blockchain", "verifytxoutproof", &verifytxoutproof, {"proof"} }, diff --git a/test/functional/rpc_psbt.py b/test/functional/rpc_psbt.py index bae98fba07..aeba3a2bf8 100755 --- a/test/functional/rpc_psbt.py +++ b/test/functional/rpc_psbt.py @@ -263,6 +263,28 @@ class PSBTTest(BitcoinTestFramework): joined_decoded = self.nodes[0].decodepsbt(joined) assert len(joined_decoded['inputs']) == 4 and len(joined_decoded['outputs']) == 2 and "final_scriptwitness" not in joined_decoded['inputs'][3] and "final_scriptSig" not in joined_decoded['inputs'][3] + # Newly created PSBT needs UTXOs and updating + addr = self.nodes[1].getnewaddress() + txid = self.nodes[0].sendtoaddress(addr, 7) + self.nodes[0].generate(6) + self.sync_all() + vout = find_output(self.nodes[0], txid, 7) + psbt = self.nodes[1].createpsbt([{"txid":txid, "vout":vout}], {self.nodes[0].getnewaddress():Decimal('6.999')}) + analyzed = self.nodes[0].analyzepsbt(psbt) + assert not analyzed['inputs'][0]['has_utxo'] and not analyzed['inputs'][0]['is_final'] and analyzed['inputs'][0]['next'] == 'updater' and analyzed['next'] == 'updater' + + # After update with wallet, only needs signing + updated = self.nodes[1].walletprocesspsbt(psbt, False, 'ALL', True)['psbt'] + analyzed = self.nodes[0].analyzepsbt(updated) + assert analyzed['inputs'][0]['has_utxo'] and not analyzed['inputs'][0]['is_final'] and analyzed['inputs'][0]['next'] == 'signer' and analyzed['next'] == 'signer' + + # Check fee and size things + assert analyzed['fee'] == Decimal('0.00100000') and analyzed['estimated_vsize'] == 191 and analyzed['estimated_feerate'] == Decimal('0.00523560') + + # After signing and finalizing, needs extracting + signed = self.nodes[1].walletprocesspsbt(updated)['psbt'] + analyzed = self.nodes[0].analyzepsbt(signed) + assert analyzed['inputs'][0]['has_utxo'] and analyzed['inputs'][0]['is_final'] and analyzed['next'] == 'extractor' if __name__ == '__main__': PSBTTest().main()