feat(pczt): Add implementation of PCZT signing (#4576)

* feat(pczt): Add implementation of PCZT signing

* feat(pczt): Add a successfully broadcasted tx test

* feat(pczt): Address PR comments

Author: satoshiotomakan

rust/Cargo.lock

@@ -4,8 +4,8 @@
 
 use crate::modules::protobuf_builder::standard_protobuf_builder::StandardProtobufBuilder;
 use crate::modules::protobuf_builder::ProtobufBuilder;
-use crate::modules::psbt_request::standard_psbt_request_builder::StandardPsbtRequestBuilder;
-use crate::modules::psbt_request::PsbtRequestBuilder;
+use crate::modules::psbt_request::standard_psbt_request_handler::StandardPsbtRequestHandler;
+use crate::modules::psbt_request::PsbtRequestHandler;
 use crate::modules::signing_request::standard_signing_request::StandardSigningRequestBuilder;
 use crate::modules::signing_request::SigningRequestBuilder;
 use tw_coin_entry::error::prelude::SigningResult;
@@ -21,7 +21,7 @@ use tw_utxo::transaction::standard_transaction::Transaction;
 pub trait BitcoinSigningContext: UtxoContext + Sized {
     type SigningRequestBuilder: SigningRequestBuilder<Self>;
     type ProtobufBuilder: ProtobufBuilder<Self>;
-    type PsbtRequestBuilder: PsbtRequestBuilder<Self>;
+    type PsbtRequestHandler: PsbtRequestHandler<Self>;
 }
 
 #[derive(Default)]
@@ -31,6 +31,7 @@ impl UtxoContext for StandardBitcoinContext {
     type Address = StandardBitcoinAddress;
     type Transaction = Transaction;
     type FeeEstimator = StandardFeeEstimator<Self::Transaction>;
+    type Psbt = bitcoin::psbt::Psbt;
 
     fn addr_to_script_pubkey(
         addr: &Self::Address,
@@ -49,5 +50,5 @@ impl UtxoContext for StandardBitcoinContext {
 impl BitcoinSigningContext for StandardBitcoinContext {
     type SigningRequestBuilder = StandardSigningRequestBuilder;
     type ProtobufBuilder = StandardProtobufBuilder;
-    type PsbtRequestBuilder = StandardPsbtRequestBuilder;
+    type PsbtRequestHandler = StandardPsbtRequestHandler;
 }

rust/chains/tw_bitcoin/src/context.rs

@@ -4,7 +4,7 @@
 
 use crate::context::BitcoinSigningContext;
 use crate::modules::protobuf_builder::ProtobufBuilder;
-use crate::modules::psbt_request::{PsbtRequest, PsbtRequestBuilder};
+use crate::modules::psbt_request::{PsbtRequest, PsbtRequestHandler};
 use crate::modules::signing_request::SigningRequestBuilder;
 use std::borrow::Cow;
 use std::marker::PhantomData;
@@ -53,7 +53,7 @@ impl<Context: BitcoinSigningContext> BitcoinCompiler<Context> {
                 TxPlanner::plan(request)?.unsigned_tx
             },
             TransactionType::psbt(ref psbt) => {
-                Context::PsbtRequestBuilder::build(&input, psbt)?.unsigned_tx
+                Context::PsbtRequestHandler::parse_request(&input, psbt)?.unsigned_tx
             },
             TransactionType::None => {
                 return SigningError::err(SigningErrorType::Error_invalid_params)
@@ -137,7 +137,8 @@ impl<Context: BitcoinSigningContext> BitcoinCompiler<Context> {
         psbt: &Proto::Psbt,
         signatures: Vec<SignatureBytes>,
     ) -> SigningResult<Proto::SigningOutput<'static>> {
-        let PsbtRequest { unsigned_tx, .. } = Context::PsbtRequestBuilder::build(input, psbt)?;
+        let PsbtRequest { unsigned_tx, .. } =
+            Context::PsbtRequestHandler::parse_request(input, psbt)?;
         let fee = unsigned_tx.fee()?;
 
         SighashVerifier::verify_signatures(&unsigned_tx, &signatures)?;

rust/chains/tw_bitcoin/src/modules/compiler.rs

@@ -5,7 +5,6 @@
 pub mod compiler;
 pub mod planner;
 pub mod protobuf_builder;
-pub mod psbt;
 pub mod psbt_request;
 pub mod signer;
 pub mod signing_request;

rust/chains/tw_bitcoin/src/modules/mod.rs

@@ -3,7 +3,7 @@
 // Copyright © 2017 Trust Wallet.
 
 use crate::context::BitcoinSigningContext;
-use crate::modules::psbt_request::{PsbtRequest, PsbtRequestBuilder};
+use crate::modules::psbt_request::{PsbtRequest, PsbtRequestHandler};
 use crate::modules::signing_request::standard_signing_request::chain_info;
 use crate::modules::tx_builder::script_parser::StandardScriptParser;
 use crate::modules::tx_builder::BitcoinChainInfo;
@@ -32,7 +32,7 @@ impl<Context: BitcoinSigningContext> PsbtPlanner<Context> {
     ) -> SigningResult<Proto::TransactionPlan<'static>> {
         let chain_info = chain_info(coin, &input.chain_info)?;
         let PsbtRequest { unsigned_tx, .. } =
-            Context::PsbtRequestBuilder::build(input, psbt_input)?;
+            Context::PsbtRequestHandler::parse_request(input, psbt_input)?;
 
         let total_input = unsigned_tx.total_input()?;
         let fee_estimate = unsigned_tx.fee()?;

rust/chains/tw_bitcoin/src/modules/planner/psbt_planner.rs

@@ -2,38 +2,62 @@
 //
 // Copyright © 2017 Trust Wallet.
 
-use bitcoin::psbt::Psbt;
 use std::marker::PhantomData;
 use tw_coin_entry::error::prelude::*;
+use tw_memory::Data;
 use tw_proto::BitcoinV2::Proto;
 use tw_utxo::context::UtxoContext;
 use tw_utxo::transaction::unsigned_transaction::UnsignedTransaction;
 
 pub mod output_psbt;
-pub mod standard_psbt_request_builder;
+pub mod standard_psbt_request_handler;
 pub mod utxo_psbt;
 
-pub trait PsbtRequestBuilder<Context: UtxoContext> {
-    fn build(
+pub trait PsbtRequestHandler<Context: UtxoContext> {
+    /// Parses a PSBT request from Protobuf.
+    fn parse_request(
         input: &Proto::SigningInput,
         psbt_input: &Proto::Psbt,
     ) -> SigningResult<PsbtRequest<Context>>;
+
+    /// Finalizes the [Partially Signed Bitcoin Transaction](Psbt)
+    /// by updating the final `script_sig` and/or `witness`.
+    fn update_signed(
+        psbt: &mut Context::Psbt,
+        signed_tx: &Context::Transaction,
+    ) -> SigningResult<()>;
+
+    /// Serializes the PSBT into bytes.
+    fn serialize_psbt(psbt: &Context::Psbt) -> SigningResult<Data>;
 }
 
 pub struct PsbtRequest<Context: UtxoContext> {
-    pub psbt: Psbt,
+    pub psbt: Context::Psbt,
     pub unsigned_tx: UnsignedTransaction<Context::Transaction>,
-    _phantom: PhantomData<Context>,
+    pub _phantom: PhantomData<Context>,
 }
 
 pub struct NoPsbtRequestBuilder;
 
-impl<Context: UtxoContext> PsbtRequestBuilder<Context> for NoPsbtRequestBuilder {
-    fn build(
+impl<Context: UtxoContext> PsbtRequestHandler<Context> for NoPsbtRequestBuilder {
+    fn parse_request(
         _input: &Proto::SigningInput,
         _psbt_input: &Proto::Psbt,
     ) -> SigningResult<PsbtRequest<Context>> {
         SigningError::err(SigningErrorType::Error_not_supported)
             .context("PSBT signing is not supported")
     }
+
+    fn update_signed(
+        _psbt: &mut Context::Psbt,
+        _signed_tx: &Context::Transaction,
+    ) -> SigningResult<()> {
+        SigningError::err(SigningErrorType::Error_not_supported)
+            .context("PSBT signing is not supported")
+    }
+
+    fn serialize_psbt(_psbt: &Context::Psbt) -> SigningResult<Data> {
+        SigningError::err(SigningErrorType::Error_not_supported)
+            .context("PSBT signing is not supported")
+    }
 }

rust/chains/tw_bitcoin/src/modules/psbt.rs

@@ -4,23 +4,26 @@
 
 use crate::modules::psbt_request::output_psbt::OutputPsbt;
 use crate::modules::psbt_request::utxo_psbt::UtxoPsbt;
-use crate::modules::psbt_request::{PsbtRequest, PsbtRequestBuilder};
+use crate::modules::psbt_request::{PsbtRequest, PsbtRequestHandler};
 use crate::modules::signing_request::standard_signing_request::StandardSigningRequestBuilder;
-use bitcoin::psbt::Psbt;
 use std::marker::PhantomData;
 use tw_coin_entry::error::prelude::*;
+use tw_memory::Data;
 use tw_proto::BitcoinV2::Proto;
 use tw_utxo::context::UtxoContext;
 use tw_utxo::transaction::standard_transaction::builder::TransactionBuilder;
 use tw_utxo::transaction::standard_transaction::Transaction;
+use tw_utxo::transaction::transaction_interface::{TransactionInterface, TxInputInterface};
 
-pub struct StandardPsbtRequestBuilder;
+pub use bitcoin::psbt::Psbt;
 
-impl<Context> PsbtRequestBuilder<Context> for StandardPsbtRequestBuilder
+pub struct StandardPsbtRequestHandler;
+
+impl<Context> PsbtRequestHandler<Context> for StandardPsbtRequestHandler
 where
-    Context: UtxoContext<Transaction = Transaction>,
+    Context: UtxoContext<Transaction = Transaction, Psbt = Psbt>,
 {
-    fn build(
+    fn parse_request(
         input: &Proto::SigningInput,
         psbt_input: &Proto::Psbt,
     ) -> SigningResult<PsbtRequest<Context>> {
@@ -66,4 +69,34 @@ where
             _phantom: PhantomData,
         })
     }
+
+    fn update_signed(
+        psbt: &mut Context::Psbt,
+        signed_tx: &Context::Transaction,
+    ) -> SigningResult<()> {
+        for (signed_txin, utxo_psbt) in signed_tx.inputs().iter().zip(psbt.inputs.iter_mut()) {
+            if signed_txin.has_script_sig() {
+                utxo_psbt.final_script_sig = Some(bitcoin::ScriptBuf::from_bytes(
+                    signed_txin.script_sig().to_vec(),
+                ));
+            }
+
+            if let Some(witness) = signed_txin.witness() {
+                if witness.is_empty() {
+                    continue;
+                }
+
+                let mut final_witness = bitcoin::Witness::new();
+                for witness_item in witness.as_items() {
+                    final_witness.push(bitcoin::ScriptBuf::from_bytes(witness_item.to_vec()));
+                }
+                utxo_psbt.final_script_witness = Some(final_witness);
+            }
+        }
+        Ok(())
+    }
+
+    fn serialize_psbt(psbt: &Context::Psbt) -> SigningResult<Data> {
+        Ok(psbt.serialize())
+    }
 }

rust/chains/tw_bitcoin/src/modules/psbt_request/mod.rs

@@ -96,7 +96,7 @@ impl<'a> UtxoPsbt<'a> {
             },
             StandardScript::P2SH(_) | StandardScript::P2WSH(_) => {
                 SigningError::err(SigningErrorType::Error_not_supported)
-                    .context("P2SH and P2WSH scriptPubkey's are not supported yet")
+                    .context("P2SH and P2WSH scriptPubkeys are not supported yet")
             },
             StandardScript::OpReturn(_) => SigningError::err(SigningErrorType::Error_invalid_utxo)
                 .context("Cannot spend an OP_RETURN output"),

rust/chains/tw_bitcoin/src/modules/psbt_request/standard_psbt_request_builder.rs renamed to rust/chains/tw_bitcoin/src/modules/psbt_request/standard_psbt_request_handler.rs

@@ -4,8 +4,7 @@
 
 use crate::context::BitcoinSigningContext;
 use crate::modules::protobuf_builder::ProtobufBuilder;
-use crate::modules::psbt::update_psbt_signed;
-use crate::modules::psbt_request::{PsbtRequest, PsbtRequestBuilder};
+use crate::modules::psbt_request::{PsbtRequest, PsbtRequestHandler};
 use crate::modules::signing_request::SigningRequestBuilder;
 use std::borrow::Cow;
 use std::marker::PhantomData;
@@ -89,7 +88,7 @@ impl<Context: BitcoinSigningContext> BitcoinSigner<Context> {
             mut psbt,
             unsigned_tx,
             ..
-        } = Context::PsbtRequestBuilder::build(input, psbt_input)?;
+        } = Context::PsbtRequestHandler::parse_request(input, psbt_input)?;
 
         let fee = unsigned_tx.fee()?;
 
@@ -102,7 +101,7 @@ impl<Context: BitcoinSigningContext> BitcoinSigner<Context> {
         let signed_tx =
             TxSigner::sign_tx(unsigned_tx, &keys_manager).context("Error signing transaction")?;
 
-        update_psbt_signed(&mut psbt, &signed_tx);
+        Context::PsbtRequestHandler::update_signed(&mut psbt, &signed_tx)?;
 
         Ok(Proto::SigningOutput {
             transaction: Context::ProtobufBuilder::tx_to_proto(&signed_tx),
@@ -113,7 +112,7 @@ impl<Context: BitcoinSigningContext> BitcoinSigner<Context> {
             fee,
             weight: signed_tx.weight() as u64,
             psbt: Some(Proto::Psbt {
-                psbt: Cow::from(psbt.serialize()),
+                psbt: Cow::from(Context::PsbtRequestHandler::serialize_psbt(&psbt)?),
             }),
             ..Proto::SigningOutput::default()
         })