Construct and use PrecomputedTransactionData in PSBT signing

This commit is contained in:
Pieter Wuille 2021-03-03 16:47:44 -08:00
parent 5cb6502ac5
commit fd3f6890f3
10 changed files with 50 additions and 21 deletions

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@ -23,6 +23,8 @@ PSBTAnalysis AnalyzePSBT(PartiallySignedTransaction psbtx)
result.inputs.resize(psbtx.tx->vin.size());
const PrecomputedTransactionData txdata = PrecomputePSBTData(psbtx);
for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
PSBTInput& input = psbtx.inputs[i];
PSBTInputAnalysis& input_analysis = result.inputs[i];
@ -61,7 +63,7 @@ PSBTAnalysis AnalyzePSBT(PartiallySignedTransaction psbtx)
// Figure out what is missing
SignatureData outdata;
bool complete = SignPSBTInput(DUMMY_SIGNING_PROVIDER, psbtx, i, 1, &outdata);
bool complete = SignPSBTInput(DUMMY_SIGNING_PROVIDER, psbtx, i, &txdata, 1, &outdata);
// Things are missing
if (!complete) {
@ -121,7 +123,7 @@ PSBTAnalysis AnalyzePSBT(PartiallySignedTransaction psbtx)
PSBTInput& input = psbtx.inputs[i];
Coin newcoin;
if (!SignPSBTInput(DUMMY_SIGNING_PROVIDER, psbtx, i, 1, nullptr, true) || !psbtx.GetInputUTXO(newcoin.out, i)) {
if (!SignPSBTInput(DUMMY_SIGNING_PROVIDER, psbtx, i, nullptr, 1) || !psbtx.GetInputUTXO(newcoin.out, i)) {
success = false;
break;
} else {

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@ -227,7 +227,24 @@ void UpdatePSBTOutput(const SigningProvider& provider, PartiallySignedTransactio
psbt_out.FromSignatureData(sigdata);
}
bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction& psbt, int index, int sighash, SignatureData* out_sigdata, bool use_dummy)
PrecomputedTransactionData PrecomputePSBTData(const PartiallySignedTransaction& psbt)
{
const CMutableTransaction& tx = *psbt.tx;
bool have_all_spent_outputs = true;
std::vector<CTxOut> utxos(tx.vin.size());
for (size_t idx = 0; idx < tx.vin.size(); ++idx) {
if (!psbt.GetInputUTXO(utxos[idx], idx)) have_all_spent_outputs = false;
}
PrecomputedTransactionData txdata;
if (have_all_spent_outputs) {
txdata.Init(tx, std::move(utxos), true);
} else {
txdata.Init(tx, {}, true);
}
return txdata;
}
bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction& psbt, int index, const PrecomputedTransactionData* txdata, int sighash, SignatureData* out_sigdata)
{
PSBTInput& input = psbt.inputs.at(index);
const CMutableTransaction& tx = *psbt.tx;
@ -267,10 +284,10 @@ bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction&
sigdata.witness = false;
bool sig_complete;
if (use_dummy) {
if (txdata == nullptr) {
sig_complete = ProduceSignature(provider, DUMMY_SIGNATURE_CREATOR, utxo.scriptPubKey, sigdata);
} else {
MutableTransactionSignatureCreator creator(&tx, index, utxo.nValue, sighash);
MutableTransactionSignatureCreator creator(&tx, index, utxo.nValue, txdata, sighash);
sig_complete = ProduceSignature(provider, creator, utxo.scriptPubKey, sigdata);
}
// Verify that a witness signature was produced in case one was required.
@ -302,8 +319,9 @@ bool FinalizePSBT(PartiallySignedTransaction& psbtx)
// PartiallySignedTransaction did not understand them), this will combine them into a final
// script.
bool complete = true;
const PrecomputedTransactionData txdata = PrecomputePSBTData(psbtx);
for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
complete &= SignPSBTInput(DUMMY_SIGNING_PROVIDER, psbtx, i, SIGHASH_ALL);
complete &= SignPSBTInput(DUMMY_SIGNING_PROVIDER, psbtx, i, &txdata, SIGHASH_ALL);
}
return complete;

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@ -567,11 +567,18 @@ enum class PSBTRole {
std::string PSBTRoleName(PSBTRole role);
/** Compute a PrecomputedTransactionData object from a psbt. */
PrecomputedTransactionData PrecomputePSBTData(const PartiallySignedTransaction& psbt);
/** Checks whether a PSBTInput is already signed. */
bool PSBTInputSigned(const 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, SignatureData* out_sigdata = nullptr, bool use_dummy = false);
/** Signs a PSBTInput, verifying that all provided data matches what is being signed.
*
* txdata should be the output of PrecomputePSBTData (which can be shared across
* multiple SignPSBTInput calls). If it is nullptr, a dummy signature will be created.
**/
bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction& psbt, int index, const PrecomputedTransactionData* txdata, int sighash = SIGHASH_ALL, SignatureData* out_sigdata = nullptr);
/** Counts the unsigned inputs of a PSBT. */
size_t CountPSBTUnsignedInputs(const PartiallySignedTransaction& psbt);

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@ -1655,6 +1655,7 @@ static RPCHelpMan utxoupdatepsbt()
}
// Fill the inputs
const PrecomputedTransactionData txdata = PrecomputePSBTData(psbtx);
for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
PSBTInput& input = psbtx.inputs.at(i);
@ -1671,7 +1672,7 @@ static RPCHelpMan utxoupdatepsbt()
// Update script/keypath information using descriptor data.
// Note that SignPSBTInput does a lot more than just constructing ECDSA signatures
// we don't actually care about those here, in fact.
SignPSBTInput(public_provider, psbtx, i, /* sighash_type */ 1);
SignPSBTInput(public_provider, psbtx, i, &txdata, /* sighash_type */ 1);
}
// Update script/keypath information using descriptor data.

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@ -62,10 +62,10 @@ bool ExternalSignerScriptPubKeyMan::DisplayAddress(const CScript scriptPubKey, c
}
// If sign is true, transaction must previously have been filled
TransactionError ExternalSignerScriptPubKeyMan::FillPSBT(PartiallySignedTransaction& psbt, int sighash_type, bool sign, bool bip32derivs, int* n_signed) const
TransactionError ExternalSignerScriptPubKeyMan::FillPSBT(PartiallySignedTransaction& psbt, const PrecomputedTransactionData& txdata, int sighash_type, bool sign, bool bip32derivs, int* n_signed) const
{
if (!sign) {
return DescriptorScriptPubKeyMan::FillPSBT(psbt, sighash_type, false, bip32derivs, n_signed);
return DescriptorScriptPubKeyMan::FillPSBT(psbt, txdata, sighash_type, false, bip32derivs, n_signed);
}
// Already complete if every input is now signed

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@ -29,7 +29,7 @@ class ExternalSignerScriptPubKeyMan : public DescriptorScriptPubKeyMan
bool DisplayAddress(const CScript scriptPubKey, const ExternalSigner &signer) const;
TransactionError FillPSBT(PartiallySignedTransaction& psbt, int sighash_type = 1 /* SIGHASH_ALL */, bool sign = true, bool bip32derivs = false, int* n_signed = nullptr) const override;
TransactionError FillPSBT(PartiallySignedTransaction& psbt, const PrecomputedTransactionData& txdata, int sighash_type = 1 /* SIGHASH_ALL */, bool sign = true, bool bip32derivs = false, int* n_signed = nullptr) const override;
};
#endif

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@ -597,7 +597,7 @@ SigningResult LegacyScriptPubKeyMan::SignMessage(const std::string& message, con
return SigningResult::SIGNING_FAILED;
}
TransactionError LegacyScriptPubKeyMan::FillPSBT(PartiallySignedTransaction& psbtx, int sighash_type, bool sign, bool bip32derivs, int* n_signed) const
TransactionError LegacyScriptPubKeyMan::FillPSBT(PartiallySignedTransaction& psbtx, const PrecomputedTransactionData& txdata, int sighash_type, bool sign, bool bip32derivs, int* n_signed) const
{
if (n_signed) {
*n_signed = 0;
@ -626,7 +626,7 @@ TransactionError LegacyScriptPubKeyMan::FillPSBT(PartiallySignedTransaction& psb
}
SignatureData sigdata;
input.FillSignatureData(sigdata);
SignPSBTInput(HidingSigningProvider(this, !sign, !bip32derivs), psbtx, i, sighash_type);
SignPSBTInput(HidingSigningProvider(this, !sign, !bip32derivs), psbtx, i, &txdata, sighash_type);
bool signed_one = PSBTInputSigned(input);
if (n_signed && (signed_one || !sign)) {
@ -2083,7 +2083,7 @@ SigningResult DescriptorScriptPubKeyMan::SignMessage(const std::string& message,
return SigningResult::OK;
}
TransactionError DescriptorScriptPubKeyMan::FillPSBT(PartiallySignedTransaction& psbtx, int sighash_type, bool sign, bool bip32derivs, int* n_signed) const
TransactionError DescriptorScriptPubKeyMan::FillPSBT(PartiallySignedTransaction& psbtx, const PrecomputedTransactionData& txdata, int sighash_type, bool sign, bool bip32derivs, int* n_signed) const
{
if (n_signed) {
*n_signed = 0;
@ -2133,7 +2133,7 @@ TransactionError DescriptorScriptPubKeyMan::FillPSBT(PartiallySignedTransaction&
}
}
SignPSBTInput(HidingSigningProvider(keys.get(), !sign, !bip32derivs), psbtx, i, sighash_type);
SignPSBTInput(HidingSigningProvider(keys.get(), !sign, !bip32derivs), psbtx, i, &txdata, sighash_type);
bool signed_one = PSBTInputSigned(input);
if (n_signed && (signed_one || !sign)) {

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@ -235,7 +235,7 @@ public:
/** Sign a message with the given script */
virtual SigningResult SignMessage(const std::string& message, const PKHash& pkhash, std::string& str_sig) const { return SigningResult::SIGNING_FAILED; };
/** Adds script and derivation path information to a PSBT, and optionally signs it. */
virtual TransactionError FillPSBT(PartiallySignedTransaction& psbt, int sighash_type = 1 /* SIGHASH_ALL */, bool sign = true, bool bip32derivs = false, int* n_signed = nullptr) const { return TransactionError::INVALID_PSBT; }
virtual TransactionError FillPSBT(PartiallySignedTransaction& psbt, const PrecomputedTransactionData& txdata, int sighash_type = 1 /* SIGHASH_ALL */, bool sign = true, bool bip32derivs = false, int* n_signed = nullptr) const { return TransactionError::INVALID_PSBT; }
virtual uint256 GetID() const { return uint256(); }
@ -394,7 +394,7 @@ public:
bool SignTransaction(CMutableTransaction& tx, const std::map<COutPoint, Coin>& coins, int sighash, std::map<int, std::string>& input_errors) const override;
SigningResult SignMessage(const std::string& message, const PKHash& pkhash, std::string& str_sig) const override;
TransactionError FillPSBT(PartiallySignedTransaction& psbt, int sighash_type = 1 /* SIGHASH_ALL */, bool sign = true, bool bip32derivs = false, int* n_signed = nullptr) const override;
TransactionError FillPSBT(PartiallySignedTransaction& psbt, const PrecomputedTransactionData& txdata, int sighash_type = 1 /* SIGHASH_ALL */, bool sign = true, bool bip32derivs = false, int* n_signed = nullptr) const override;
uint256 GetID() const override;
@ -605,7 +605,7 @@ public:
bool SignTransaction(CMutableTransaction& tx, const std::map<COutPoint, Coin>& coins, int sighash, std::map<int, std::string>& input_errors) const override;
SigningResult SignMessage(const std::string& message, const PKHash& pkhash, std::string& str_sig) const override;
TransactionError FillPSBT(PartiallySignedTransaction& psbt, int sighash_type = 1 /* SIGHASH_ALL */, bool sign = true, bool bip32derivs = false, int* n_signed = nullptr) const override;
TransactionError FillPSBT(PartiallySignedTransaction& psbt, const PrecomputedTransactionData& txdata, int sighash_type = 1 /* SIGHASH_ALL */, bool sign = true, bool bip32derivs = false, int* n_signed = nullptr) const override;
uint256 GetID() const override;

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@ -71,7 +71,7 @@ BOOST_AUTO_TEST_CASE(psbt_updater_test)
// Try to sign the mutated input
SignatureData sigdata;
BOOST_CHECK(spk_man->FillPSBT(psbtx, SIGHASH_ALL, true, true) != TransactionError::OK);
BOOST_CHECK(spk_man->FillPSBT(psbtx, PrecomputePSBTData(psbtx), SIGHASH_ALL, true, true) != TransactionError::OK);
}
BOOST_AUTO_TEST_CASE(parse_hd_keypath)

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@ -1830,6 +1830,7 @@ TransactionError CWallet::FillPSBT(PartiallySignedTransaction& psbtx, bool& comp
if (n_signed) {
*n_signed = 0;
}
const PrecomputedTransactionData txdata = PrecomputePSBTData(psbtx);
LOCK(cs_wallet);
// Get all of the previous transactions
for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
@ -1856,7 +1857,7 @@ TransactionError CWallet::FillPSBT(PartiallySignedTransaction& psbtx, bool& comp
// Fill in information from ScriptPubKeyMans
for (ScriptPubKeyMan* spk_man : GetAllScriptPubKeyMans()) {
int n_signed_this_spkm = 0;
TransactionError res = spk_man->FillPSBT(psbtx, sighash_type, sign, bip32derivs, &n_signed_this_spkm);
TransactionError res = spk_man->FillPSBT(psbtx, txdata, sighash_type, sign, bip32derivs, &n_signed_this_spkm);
if (res != TransactionError::OK) {
return res;
}