Merge pull request #172 from benthecarman/sign-psbt

Change Signer::sign_tx_input to Signer::sign_psbt_input

bitcoin-rpc-provider/src/lib.rs

@@ -7,6 +7,7 @@ use std::sync::{Arc, Mutex};
 use std::time::Duration;
 
 use bitcoin::consensus::encode::Error as EncodeError;
+use bitcoin::psbt::PartiallySignedTransaction;
 use bitcoin::secp256k1::rand::thread_rng;
 use bitcoin::secp256k1::{PublicKey, SecretKey};
 use bitcoin::{
@@ -185,14 +186,32 @@ impl Signer for BitcoinCoreProvider {
         Ok(pk.inner)
     }
 
-    fn sign_tx_input(
+    fn sign_psbt_input(
         &self,
-        tx: &mut Transaction,
+        psbt: &mut PartiallySignedTransaction,
         input_index: usize,
-        tx_out: &TxOut,
-        redeem_script: Option<Script>,
     ) -> Result<(), ManagerError> {
-        let outpoint = &tx.input[input_index].previous_output;
+        let outpoint = &psbt.unsigned_tx.input[input_index].previous_output;
+        let tx_out = if let Some(input) = psbt.inputs.get(input_index) {
+            if let Some(wit_utxo) = &input.witness_utxo {
+                Ok(wit_utxo.clone())
+            } else if let Some(in_tx) = &input.non_witness_utxo {
+                Ok(in_tx.output[outpoint.vout as usize].clone())
+            } else {
+                Err(ManagerError::InvalidParameters(
+                    "No TxOut for PSBT input".to_string(),
+                ))
+            }
+        } else {
+            Err(ManagerError::InvalidParameters(
+                "No TxOut for PSBT input".to_string(),
+            ))
+        }?;
+
+        let redeem_script = psbt
+            .inputs
+            .get(input_index)
+            .and_then(|i| i.redeem_script.clone());
 
         let input = json::SignRawTransactionInput {
             txid: outpoint.txid,
@@ -206,13 +225,15 @@ impl Signer for BitcoinCoreProvider {
             .client
             .lock()
             .unwrap()
-            .sign_raw_transaction_with_wallet(&*tx, Some(&[input]), None)
+            .sign_raw_transaction_with_wallet(&psbt.unsigned_tx, Some(&[input]), None)
             .map_err(rpc_err_to_manager_err)?;
         let signed_tx = Transaction::consensus_decode(&mut sign_result.hex.as_slice())
             .map_err(enc_err_to_manager_err)?;
 
-        tx.input[input_index].script_sig = signed_tx.input[input_index].script_sig.clone();
-        tx.input[input_index].witness = signed_tx.input[input_index].witness.clone();
+        psbt.inputs[input_index].final_script_sig =
+            Some(signed_tx.input[input_index].script_sig.clone());
+        psbt.inputs[input_index].final_script_witness =
+            Some(signed_tx.input[input_index].witness.clone());
 
         Ok(())
     }

dlc-manager/src/channel_updater.rs

@@ -435,7 +435,7 @@ pub fn verify_signed_channel<S: Deref>(
     accepted_contract: &AcceptedContract,
     sign_channel: &SignChannel,
     signer: &S,
-) -> Result<(SignedChannel, SignedContract), Error>
+) -> Result<(SignedChannel, SignedContract, Transaction), Error>
 where
     S::Target: Signer,
 {
@@ -458,7 +458,7 @@ where
 
     let cet_adaptor_signatures: Vec<_> = (&sign_channel.cet_adaptor_signatures).into();
 
-    let (signed_contract, fund_tx) = verify_signed_contract_internal(
+    let (signed_contract, signed_fund_tx) = verify_signed_contract_internal(
         secp,
         accepted_contract,
         &sign_channel.refund_signature,
@@ -493,7 +493,11 @@ where
             is_offer: false,
         },
         update_idx: INITIAL_UPDATE_NUMBER,
-        fund_tx,
+        fund_tx: signed_contract
+            .accepted_contract
+            .dlc_transactions
+            .fund
+            .clone(),
         fund_script_pubkey: accepted_contract
             .dlc_transactions
             .funding_script_pubkey
@@ -507,7 +511,7 @@ where
             .fee_rate_per_vb,
     };
 
-    Ok((signed_channel, signed_contract))
+    Ok((signed_channel, signed_contract, signed_fund_tx))
 }
 
 /// Creates a [`SettleOffer`] message from the given [`SignedChannel`] and parameters,

dlc-manager/src/contract_updater.rs

@@ -2,6 +2,7 @@
 
 use std::ops::Deref;
 
+use bitcoin::psbt::PartiallySignedTransaction;
 use bitcoin::{consensus::Decodable, Script, Transaction, Witness};
 use dlc::{DlcTransactions, PartyParams};
 use dlc_messages::{
@@ -284,6 +285,31 @@ where
     Ok((signed_contract, signed_msg))
 }
 
+fn populate_psbt(
+    psbt: &mut PartiallySignedTransaction,
+    all_funding_inputs: &[&FundingInputInfo],
+) -> Result<(), Error> {
+    // add witness utxo to fund_psbt for all inputs
+    for (input_index, x) in all_funding_inputs.iter().enumerate() {
+        let tx = Transaction::consensus_decode(&mut x.funding_input.prev_tx.as_slice()).map_err(
+            |_| {
+                Error::InvalidParameters(
+                    "Could not decode funding input previous tx parameter".to_string(),
+                )
+            },
+        )?;
+        let vout = x.funding_input.prev_tx_vout;
+        let tx_out = tx.output.get(vout as usize).ok_or_else(|| {
+            Error::InvalidParameters(format!("Previous tx output not found at index {}", vout))
+        })?;
+
+        psbt.inputs[input_index].witness_utxo = Some(tx_out.clone());
+        psbt.inputs[input_index].redeem_script = Some(x.funding_input.redeem_script.clone());
+    }
+
+    Ok(())
+}
+
 pub(crate) fn verify_accepted_and_sign_contract_internal<S: Deref>(
     secp: &Secp256k1<All>,
     offered_contract: &OfferedContract,
@@ -309,7 +335,8 @@ where
         funding_script_pubkey,
     } = dlc_transactions;
 
-    let mut fund = fund.clone();
+    let mut fund_psbt = PartiallySignedTransaction::from_unsigned_tx(fund.clone())
+        .map_err(|_| Error::InvalidState("Tried to create PSBT from signed tx".to_string()))?;
     let mut cets = cets.clone();
 
     let input_script_pubkey = input_script_pubkey.unwrap_or_else(|| funding_script_pubkey.clone());
@@ -392,43 +419,42 @@ where
         own_signatures.extend(sigs);
     }
 
-    let mut input_serial_ids: Vec<_> = offered_contract
+    // get all funding inputs
+    let mut all_funding_inputs = offered_contract
         .funding_inputs_info
         .iter()
-        .map(|x| x.funding_input.input_serial_id)
-        .chain(accept_params.inputs.iter().map(|x| x.serial_id))
-        .collect();
-    input_serial_ids.sort_unstable();
+        .chain(funding_inputs_info.iter())
+        .collect::<Vec<_>>();
+    // sort by serial id
+    all_funding_inputs.sort_by_key(|x| x.funding_input.input_serial_id);
+
+    populate_psbt(&mut fund_psbt, &all_funding_inputs)?;
 
     // Vec<Witness>
     let witnesses: Vec<Witness> = offered_contract
         .funding_inputs_info
         .iter()
         .map(|x| {
-            let input_index = input_serial_ids
+            let input_index = all_funding_inputs
                 .iter()
-                .position(|y| y == &x.funding_input.input_serial_id)
+                .position(|y| y.funding_input == x.funding_input)
                 .ok_or_else(|| {
                     Error::InvalidState(format!(
                         "Could not find input for serial id {}",
                         x.funding_input.input_serial_id
                     ))
                 })?;
-            let tx = Transaction::consensus_decode(&mut x.funding_input.prev_tx.as_slice())
-                .map_err(|_| {
-                    Error::InvalidParameters(
-                        "Could not decode funding input previous tx parameter".to_string(),
-                    )
-                })?;
-            let vout = x.funding_input.prev_tx_vout;
-            let tx_out = tx.output.get(vout as usize).ok_or_else(|| {
-                Error::InvalidParameters(format!("Previous tx output not found at index {}", vout))
-            })?;
 
-            // pass wallet instead of privkeys
-            signer.sign_tx_input(&mut fund, input_index, tx_out, None)?;
+            signer.sign_psbt_input(&mut fund_psbt, input_index)?;
 
-            Ok(fund.input[input_index].witness.clone())
+            let witness = fund_psbt.inputs[input_index]
+                .final_script_witness
+                .clone()
+                .ok_or(Error::InvalidParameters(
+                    "No witness from signing psbt input".to_string(),
+                ))?;
+
+            Ok(witness)
         })
         .collect::<Result<Vec<_>, Error>>()?;
 
@@ -445,8 +471,6 @@ where
         })
         .collect::<Result<Vec<_>, Error>>()?;
 
-    input_serial_ids.sort_unstable();
-
     let offer_refund_signature = dlc::util::get_raw_sig_for_tx_input(
         secp,
         refund,
@@ -457,7 +481,7 @@ where
     )?;
 
     let dlc_transactions = DlcTransactions {
-        fund,
+        fund: fund.clone(),
         cets,
         refund: refund.clone(),
         funding_script_pubkey: funding_script_pubkey.clone(),
@@ -565,63 +589,57 @@ where
         )?;
     }
 
-    let mut input_serials: Vec<_> = offered_contract
+    let fund_tx = &accepted_contract.dlc_transactions.fund;
+    let mut fund_psbt = PartiallySignedTransaction::from_unsigned_tx(fund_tx.clone())
+        .map_err(|_| Error::InvalidState("Tried to create PSBT from signed tx".to_string()))?;
+
+    // get all funding inputs
+    let mut all_funding_inputs = offered_contract
         .funding_inputs_info
         .iter()
         .chain(accepted_contract.funding_inputs.iter())
-        .map(|x| x.funding_input.input_serial_id)
-        .collect();
-    input_serials.sort_unstable();
+        .collect::<Vec<_>>();
+    // sort by serial id
+    all_funding_inputs.sort_by_key(|x| x.funding_input.input_serial_id);
 
-    let mut fund_tx = accepted_contract.dlc_transactions.fund.clone();
+    populate_psbt(&mut fund_psbt, &all_funding_inputs)?;
 
     for (funding_input, funding_signatures) in offered_contract
         .funding_inputs_info
         .iter()
         .zip(funding_signatures.funding_signatures.iter())
     {
-        let input_index = input_serials
+        let input_index = all_funding_inputs
             .iter()
-            .position(|x| x == &funding_input.funding_input.input_serial_id)
+            .position(|x| x.funding_input == funding_input.funding_input)
             .ok_or_else(|| {
                 Error::InvalidState(format!(
                     "Could not find input for serial id {}",
                     funding_input.funding_input.input_serial_id
                 ))
             })?;
 
-        fund_tx.input[input_index].witness = Witness::from_vec(
+        fund_psbt.inputs[input_index].final_script_witness = Some(Witness::from_vec(
             funding_signatures
                 .witness_elements
                 .iter()
                 .map(|x| x.witness.clone())
                 .collect(),
-        );
+        ));
     }
 
-    for funding_input_info in &accepted_contract.funding_inputs {
-        let input_index = input_serials
+    for funding_input in &accepted_contract.funding_inputs {
+        let input_index = all_funding_inputs
             .iter()
-            .position(|x| x == &funding_input_info.funding_input.input_serial_id)
+            .position(|x| x.funding_input == funding_input.funding_input)
             .ok_or_else(|| {
                 Error::InvalidState(format!(
                     "Could not find input for serial id {}",
-                    funding_input_info.funding_input.input_serial_id,
+                    funding_input.funding_input.input_serial_id
                 ))
             })?;
-        let tx =
-            Transaction::consensus_decode(&mut funding_input_info.funding_input.prev_tx.as_slice())
-                .map_err(|_| {
-                    Error::InvalidParameters(
-                        "Could not decode funding input previous tx parameter".to_string(),
-                    )
-                })?;
-        let vout = funding_input_info.funding_input.prev_tx_vout;
-        let tx_out = tx.output.get(vout as usize).ok_or_else(|| {
-            Error::InvalidParameters(format!("Previous tx output not found at index {}", vout))
-        })?;
 
-        signer.sign_tx_input(&mut fund_tx, input_index, tx_out, None)?;
+        signer.sign_psbt_input(&mut fund_psbt, input_index)?;
     }
 
     let signed_contract = SignedContract {
@@ -632,7 +650,7 @@ where
         channel_id,
     };
 
-    Ok((signed_contract, fund_tx))
+    Ok((signed_contract, fund_psbt.extract_tx()))
 }
 
 /// Signs and return the CET that can be used to close the given contract.

dlc-manager/src/lib.rs

@@ -36,6 +36,7 @@ pub mod manager;
 pub mod payout_curve;
 mod utils;
 
+use bitcoin::psbt::PartiallySignedTransaction;
 use bitcoin::{Address, Block, OutPoint, Script, Transaction, TxOut, Txid};
 use chain_monitor::ChainMonitor;
 use channel::offered_channel::OfferedChannel;
@@ -78,12 +79,10 @@ impl Time for SystemTimeProvider {
 /// Provides signing related functionalities.
 pub trait Signer {
     /// Signs a transaction input
-    fn sign_tx_input(
+    fn sign_psbt_input(
         &self,
-        tx: &mut Transaction,
+        psbt: &mut PartiallySignedTransaction,
         input_index: usize,
-        tx_out: &TxOut,
-        redeem_script: Option<Script>,
     ) -> Result<(), Error>;
     /// Get the secret key associated with the provided public key.
     fn get_secret_key_for_pubkey(&self, pubkey: &PublicKey) -> Result<SecretKey, Error>;

dlc-manager/src/manager.rs

@@ -1390,7 +1390,7 @@ where
             Some(*peer_id)
         )?;
 
-        let (signed_channel, signed_contract) = {
+        let (signed_channel, signed_contract, signed_fund_tx) = {
             let res = verify_signed_channel(
                 &self.secp,
                 &accepted_channel,
@@ -1430,7 +1430,7 @@ where
             unreachable!();
         }
 
-        self.blockchain.send_transaction(&signed_channel.fund_tx)?;
+        self.blockchain.send_transaction(&signed_fund_tx)?;
 
         self.store.upsert_channel(
             Channel::Signed(signed_channel),

mocks/src/mock_wallet.rs

@@ -1,5 +1,6 @@
 use std::rc::Rc;
 
+use bitcoin::psbt::PartiallySignedTransaction;
 use bitcoin::{Address, PackedLockTime, Script, Transaction, TxOut};
 use dlc_manager::{error::Error, Blockchain, Signer, Utxo, Wallet};
 use secp256k1_zkp::{rand::seq::SliceRandom, SecretKey};
@@ -45,13 +46,11 @@ impl MockWallet {
 }
 
 impl Signer for MockWallet {
-    fn sign_tx_input(
+    fn sign_psbt_input(
         &self,
-        _tx: &mut bitcoin::Transaction,
-        _input_index: usize,
-        _tx_out: &bitcoin::TxOut,
-        _redeem_script: Option<bitcoin::Script>,
-    ) -> Result<(), dlc_manager::error::Error> {
+        _psbt: &mut PartiallySignedTransaction,
+        _idx: usize,
+    ) -> Result<(), Error> {
         Ok(())
     }