Skip to content

fix(utxo-lib): honor caller hashType for SmartTransaction signatures (atomic-swap offers) #6

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
caribu66 wants to merge 1 commit into
base: utxo-lib-verus
Choose a base branch
from
Open

fix(utxo-lib): honor caller hashType for SmartTransaction signatures (atomic-swap offers) #6

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
26 changes: 24 additions & 2 deletions dist/src/transaction_builder.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -749,7 +749,9 @@ TransactionBuilder.prototype.sign = function (vin, keyPair, redeemScript, hashTy
signature = ECSignature.fromRSBuffer(signature);
debug('Produced signature (r: %s, s: %s)', signature.r, signature.s);
if (input.signType === scriptTypes.SMART_TRANSACTION) {
input.signatures[i] = new SmartTransactionSignatures(1, 1, [
// Blob must declare the same hashtype used for the digest above,
// or verification fails (e.g. SIGHASH_SINGLE|ANYONECANPAY offers).
input.signatures[i] = new SmartTransactionSignatures(1, hashType, [
new SmartTransactionSignature(1, 1, pubKey, signature.toCompact().slice(1))
]).toChunk();
}
Expand All @@ -768,6 +770,17 @@ TransactionBuilder.prototype.__canModifyInputs = function () {
// any signatures?
if (input.signatures === undefined)
return true;
if (input.signType === scriptTypes.SMART_TRANSACTION) {
var smartTxSigs = SmartTransactionSignatures.fromChunk(bscript.decompile(input.signatures)[0]);
if (smartTxSigs.error != null ||
smartTxSigs.signatures.length === 0 ||
smartTxSigs.signatures.every(function (sig) { return sig.oneSignature.length === 0; })) {
return true;
}
// Smart transaction signatures declare their hash type in the
// serialized blob header, not in the trailing byte of a DER signature.
return (smartTxSigs.sigHashType & Transaction.SIGHASH_ANYONECANPAY) !== 0;
}
return input.signatures.every(function (signature) {
if (!signature)
return true;
Expand All @@ -781,7 +794,7 @@ TransactionBuilder.prototype.__canModifyInputs = function () {
TransactionBuilder.prototype.__canModifyOutputs = function () {
var nInputs = this.tx.ins.length;
var nOutputs = this.tx.outs.length;
return this.inputs.every(function (input) {
return this.inputs.every(function (input, vin) {
if (input.signatures === undefined)
return true;
if (input.signType === scriptTypes.SMART_TRANSACTION) {
Expand All @@ -791,6 +804,15 @@ TransactionBuilder.prototype.__canModifyOutputs = function () {
smartTxSigs.signatures.every(function (sig) { return sig.oneSignature.length === 0; })) {
return true;
}
// Smart transaction signatures declare their hash type in the blob
// header. SIGHASH_SINGLE binds this input to the output at the same
// index, so appending outputs is safe once that output exists.
var smartHashTypeMod = smartTxSigs.sigHashType & 0x1f;
if (smartHashTypeMod === Transaction.SIGHASH_NONE)
return true;
if (smartHashTypeMod === Transaction.SIGHASH_SINGLE)
return vin < nOutputs;
return false;
}
return input.signatures.every(function (signature) {
if (!signature)
Expand Down
32 changes: 30 additions & 2 deletions src/transaction_builder.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -860,7 +860,11 @@ TransactionBuilder.prototype.sign = function (vin, keyPair, redeemScript, hashTy
debug('Produced signature (r: %s, s: %s)', signature.r, signature.s)

if (input.signType === scriptTypes.SMART_TRANSACTION) {
input.signatures[i] = new SmartTransactionSignatures(1, 1, [
// The signature digest above is computed with the caller-requested
// hashType; the serialized blob must declare the SAME hashtype or
// verification recomputes the digest differently and fails (e.g.
// SIGHASH_SINGLE|ANYONECANPAY atomic-swap offers).
input.signatures[i] = new SmartTransactionSignatures(1, hashType, [
new SmartTransactionSignature(
1,
1,
Expand All @@ -885,6 +889,22 @@ TransactionBuilder.prototype.__canModifyInputs = function () {
// any signatures?
if (input.signatures === undefined) return true

if (input.signType === scriptTypes.SMART_TRANSACTION) {
const smartTxSigs = SmartTransactionSignatures.fromChunk(bscript.decompile(input.signatures)[0])

if (
smartTxSigs.error != null ||
smartTxSigs.signatures.length === 0 ||
smartTxSigs.signatures.every((sig) => sig.oneSignature.length === 0)
) {
return true
}

// Smart transaction signatures declare their hash type in the
// serialized blob header, not in the trailing byte of a DER signature.
return (smartTxSigs.sigHashType & Transaction.SIGHASH_ANYONECANPAY) !== 0
}

return input.signatures.every(function (signature) {
if (!signature) return true
var hashType = signatureHashType(signature)
Expand All @@ -900,7 +920,7 @@ TransactionBuilder.prototype.__canModifyOutputs = function () {
var nInputs = this.tx.ins.length
var nOutputs = this.tx.outs.length

return this.inputs.every(function (input) {
return this.inputs.every(function (input, vin) {
if (input.signatures === undefined) return true

if (input.signType === scriptTypes.SMART_TRANSACTION) {
Expand All @@ -913,6 +933,14 @@ TransactionBuilder.prototype.__canModifyOutputs = function () {
) {
return true
}

// Smart transaction signatures declare their hash type in the blob
// header. SIGHASH_SINGLE binds this input to the output at the same
// index, so appending outputs is safe once that output exists.
var smartHashTypeMod = smartTxSigs.sigHashType & 0x1f
if (smartHashTypeMod === Transaction.SIGHASH_NONE) return true
if (smartHashTypeMod === Transaction.SIGHASH_SINGLE) return vin < nOutputs
return false
}

return input.signatures.every(function (signature) {
Expand Down