creates method for taking commitments from participants and creating …

…a signing package (#4562)

ironfish-rust-nodejs/src/structs/transaction.rs

@@ -3,6 +3,7 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use std::cell::RefCell;
+
 use std::convert::TryInto;
 
 use ironfish::assets::asset_identifier::AssetIdentifier;
@@ -174,7 +175,6 @@ impl NativeTransaction {
     pub fn new(version: u8) -> Result<Self> {
         let tx_version = version.try_into().map_err(to_napi_err)?;
         let transaction = ProposedTransaction::new(tx_version);
-
         Ok(NativeTransaction { transaction })
     }
 

ironfish-rust/src/transaction/unsigned.rs

@@ -4,8 +4,13 @@
 
 use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
 use group::GroupEncoding;
+use ironfish_frost::frost::{round1::SigningCommitments, Identifier, SigningPackage};
+
 use ironfish_zkp::redjubjub::{self, Signature};
-use std::io::{self, Write};
+use std::{
+    collections::BTreeMap,
+    io::{self, Write},
+};
 
 use crate::{
     errors::IronfishError, serializing::read_scalar, transaction::Blake2b, OutputDescription,
@@ -209,4 +214,15 @@ impl UnsignedTransaction {
             randomized_public_key: self.randomized_public_key.clone(),
         })
     }
+
+    // Creates frost signing package for use in round two of FROST multisig protocol
+    // only applicable for multisig transactions
+    pub fn signing_package(
+        &self,
+        commitments: BTreeMap<Identifier, SigningCommitments>,
+    ) -> Result<SigningPackage, IronfishError> {
+        // Create the transaction signature hash
+        let data_to_sign = self.transaction_signature_hash()?;
+        Ok(SigningPackage::new(commitments, &data_to_sign))
+    }
 }