Revert "Add a mandatory --change-address parameter to buy-xmr"

This reverts commit 5463bde4

CHANGELOG.md

@@ -26,9 +26,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   The rendezvous node address (`rendezvous_point`), as well as the ASB's external addresses (`external_addresses`) to be registered, is configured in the `network` section of the ASB config file.
   A rendezvous node is provided at `/dnsaddr/rendezvous.coblox.tech/p2p/12D3KooWQUt9DkNZxEn2R5ymJzWj15MpG6mTW84kyd8vDaRZi46o` which is used as default for discovery in the CLI.
   Upon discovery using `list-sellers` CLI users are provided with quote and connection information for each ASB discovered through the rendezvous node.
-- A mandatory `--change-address` parameter to the CLI's `buy-xmr` command.
-  The provided address is used to transfer Bitcoin in case of a refund and in case the user transfers more than the specified amount into the swap.
-  For more information see [#513](https://github.com/comit-network/xmr-btc-swap/issues/513).
 
 ### Fixed
 

swap/Cargo.toml

@@ -45,7 +45,7 @@ rust_decimal_macros = "1"
 serde = { version = "1", features = [ "derive" ] }
 serde_cbor = "0.11"
 serde_json = "1"
-serde_with = { version = "1", features = [ "macros" ] }
+serde_with = { version = "1.9.4", features = [ "macros" ] }
 sha2 = "0.9"
 sigma_fun = { git = "https://github.com/LLFourn/secp256kfun", default-features = false, features = [ "ed25519", "serde" ] }
 sled = "0.34"

swap/src/bin/asb.rs

@@ -225,9 +225,7 @@ async fn main() -> Result<()> {
                 }
             };
 
-            let psbt = bitcoin_wallet
+            let psbt = bitcoin_wallet.send_to_address(address, amount).await?;
-                .send_to_address(address, amount, None)
-                .await?;
             let signed_tx = bitcoin_wallet.sign_and_finalize(psbt).await?;
 
             bitcoin_wallet.broadcast(signed_tx, "withdraw").await?;

swap/src/bin/swap.rs

@@ -58,7 +58,6 @@ async fn main() -> Result<()> {
             seller,
             bitcoin_electrum_rpc_url,
             bitcoin_target_block,
-            bitcoin_change_address,
             monero_receive_address,
             monero_daemon_address,
             tor_socks5_port,
@@ -124,7 +123,6 @@ async fn main() -> Result<()> {
                 env_config,
                 event_loop_handle,
                 monero_receive_address,
-                bitcoin_change_address,
                 amount,
             );
 

swap/src/bitcoin/lock.rs

@@ -24,7 +24,6 @@ impl TxLock {
         amount: Amount,
         A: PublicKey,
         B: PublicKey,
-        change: bitcoin::Address,
     ) -> Result<Self>
     where
         C: EstimateFeeRate,
@@ -35,9 +34,7 @@ impl TxLock {
             .address(wallet.get_network())
             .expect("can derive address from descriptor");
 
-        let psbt = wallet
+        let psbt = wallet.send_to_address(address, amount).await?;
-            .send_to_address(address, amount, Some(change))
-            .await?;
 
         Ok(Self {
             inner: psbt,
@@ -254,11 +251,7 @@ mod tests {
         wallet: &Wallet<(), bdk::database::MemoryDatabase, StaticFeeRate>,
         amount: Amount,
     ) -> PartiallySignedTransaction {
-        let change = wallet.new_address().await.unwrap();
+        TxLock::new(&wallet, amount, A, B).await.unwrap().into()
-        TxLock::new(&wallet, amount, A, B, change)
-            .await
-            .unwrap()
-            .into()
     }
 
     fn alice_and_bob() -> (PublicKey, PublicKey) {

swap/src/bitcoin/wallet.rs

@@ -314,18 +314,11 @@ where
         &self,
         address: Address,
         amount: Amount,
-        change_override: Option<Address>,
     ) -> Result<PartiallySignedTransaction> {
         if self.network != address.network {
             bail!("Cannot build PSBT because network of given address is {} but wallet is on network {}", address.network, self.network);
         }
 
-        if let Some(change) = change_override.as_ref() {
-            if self.network != change.network {
-                bail!("Cannot build PSBT because network of given address is {} but wallet is on network {}", change.network, self.network);
-            }
-        }
-
         let wallet = self.wallet.lock().await;
         let client = self.client.lock().await;
         let fee_rate = client.estimate_feerate(self.target_block)?;
@@ -352,17 +345,6 @@ where
             _ => bail!("Unexpected transaction layout"),
         }
 
-        if let ([_, change], [_, psbt_output], Some(change_override)) = (
-            &mut psbt.global.unsigned_tx.output.as_mut_slice(),
-            &mut psbt.outputs.as_mut_slice(),
-            change_override,
-        ) {
-            change.script_pubkey = change_override.script_pubkey();
-            // Might be populated based on the previously set change address, but for the
-            // overwrite we don't know unless we ask the user for more information.
-            psbt_output.bip32_derivation.clear();
-        }
-
         Ok(psbt)
     }
 
@@ -1082,8 +1064,7 @@ mod tests {
         // if the change output is below dust it will be dropped by the BDK
         for amount in above_dust..(balance - (above_dust - 1)) {
             let (A, B) = (PublicKey::random(), PublicKey::random());
-            let change = wallet.new_address().await.unwrap();
+            let txlock = TxLock::new(&wallet, bitcoin::Amount::from_sat(amount), A, B)
-            let txlock = TxLock::new(&wallet, bitcoin::Amount::from_sat(amount), A, B, change)
                 .await
                 .unwrap();
             let txlock_output = txlock.script_pubkey();
@@ -1098,30 +1079,4 @@ mod tests {
             );
         }
     }
-
-    #[tokio::test]
-    async fn can_override_change_address() {
-        let wallet = Wallet::new_funded_default_fees(50_000);
-        let custom_change = "bcrt1q08pfqpsyrt7acllzyjm8q5qsz5capvyahm49rw"
-            .parse::<Address>()
-            .unwrap();
-
-        let psbt = wallet
-            .send_to_address(
-                wallet.new_address().await.unwrap(),
-                Amount::from_sat(10_000),
-                Some(custom_change.clone()),
-            )
-            .await
-            .unwrap();
-        let transaction = wallet.sign_and_finalize(psbt).await.unwrap();
-
-        match transaction.output.as_slice() {
-            [first, change] => {
-                assert_eq!(first.value, 10_000);
-                assert_eq!(change.script_pubkey, custom_change.script_pubkey());
-            }
-            _ => panic!("expected exactly two outputs"),
-        }
-    }
 }

swap/src/cli/command.rs

@@ -74,7 +74,6 @@ where
                     bitcoin_electrum_rpc_url,
                     bitcoin_target_block,
                 },
-            bitcoin_change_address,
             monero: Monero {
                 monero_daemon_address,
             },
@@ -92,7 +91,6 @@ where
                     is_testnet,
                 )?,
                 bitcoin_target_block: bitcoin_target_block_from(bitcoin_target_block, is_testnet),
-                bitcoin_change_address,
                 monero_receive_address: validate_monero_address(
                     monero_receive_address,
                     is_testnet,
@@ -212,7 +210,6 @@ pub enum Command {
         seller: Multiaddr,
         bitcoin_electrum_rpc_url: Url,
         bitcoin_target_block: usize,
-        bitcoin_change_address: bitcoin::Address,
         monero_receive_address: monero::Address,
         monero_daemon_address: String,
         tor_socks5_port: u16,
@@ -290,12 +287,6 @@ enum RawCommand {
         #[structopt(flatten)]
         bitcoin: Bitcoin,
 
-        #[structopt(
-            long = "change-address",
-            help = "The bitcoin address where any form of change or excess funds should be sent to"
-        )]
-        bitcoin_change_address: bitcoin::Address,
-
         #[structopt(flatten)]
         monero: Monero,
 
@@ -361,7 +352,7 @@ enum RawCommand {
 }
 
 #[derive(structopt::StructOpt, Debug)]
-struct Monero {
+pub struct Monero {
     #[structopt(
         long = "monero-daemon-address",
         help = "Specify to connect to a monero daemon of your choice: <host>:<port>"
@@ -521,9 +512,7 @@ mod tests {
     const MAINNET: &str = "mainnet";
 
     const MONERO_STAGENET_ADDRESS: &str = "53gEuGZUhP9JMEBZoGaFNzhwEgiG7hwQdMCqFxiyiTeFPmkbt1mAoNybEUvYBKHcnrSgxnVWgZsTvRBaHBNXPa8tHiCU51a";
-    const BITCOIN_TESTNET_ADDRESS: &str = "tb1qr3em6k3gfnyl8r7q0v7t4tlnyxzgxma3lressv";
     const MONERO_MAINNET_ADDRESS: &str = "44Ato7HveWidJYUAVw5QffEcEtSH1DwzSP3FPPkHxNAS4LX9CqgucphTisH978FLHE34YNEx7FcbBfQLQUU8m3NUC4VqsRa";
-    const BITCOIN_MAINNET_ADDRESS: &str = "bc1qe4epnfklcaa0mun26yz5g8k24em5u9f92hy325";
     const MULTI_ADDRESS: &str =
         "/ip4/127.0.0.1/tcp/9939/p2p/12D3KooWCdMKjesXMJz1SiZ7HgotrxuqhQJbP5sgBm2BwP1cqThi";
     const SWAP_ID: &str = "ea030832-3be9-454f-bb98-5ea9a788406b";
@@ -535,8 +524,6 @@ mod tests {
             "buy-xmr",
             "--receive-address",
             MONERO_MAINNET_ADDRESS,
-            "--change-address",
-            BITCOIN_MAINNET_ADDRESS,
             "--seller",
             MULTI_ADDRESS,
         ];
@@ -555,8 +542,6 @@ mod tests {
             "buy-xmr",
             "--receive-address",
             MONERO_STAGENET_ADDRESS,
-            "--change-address",
-            BITCOIN_TESTNET_ADDRESS,
             "--seller",
             MULTI_ADDRESS,
         ];
@@ -576,8 +561,6 @@ mod tests {
             "buy-xmr",
             "--receive-address",
             MONERO_STAGENET_ADDRESS,
-            "--change-address",
-            BITCOIN_TESTNET_ADDRESS,
             "--seller",
             MULTI_ADDRESS,
         ];
@@ -601,8 +584,6 @@ mod tests {
             "buy-xmr",
             "--receive-address",
             MONERO_MAINNET_ADDRESS,
-            "--change-address",
-            BITCOIN_MAINNET_ADDRESS,
             "--seller",
             MULTI_ADDRESS,
         ];
@@ -699,8 +680,6 @@ mod tests {
             "--data-base-dir",
             data_dir,
             "buy-xmr",
-            "--change-address",
-            BITCOIN_MAINNET_ADDRESS,
             "--receive-address",
             MONERO_MAINNET_ADDRESS,
             "--seller",
@@ -723,8 +702,6 @@ mod tests {
             "--data-base-dir",
             data_dir,
             "buy-xmr",
-            "--change-address",
-            BITCOIN_TESTNET_ADDRESS,
             "--receive-address",
             MONERO_STAGENET_ADDRESS,
             "--seller",
@@ -787,8 +764,6 @@ mod tests {
             BINARY_NAME,
             "--debug",
             "buy-xmr",
-            "--change-address",
-            BITCOIN_MAINNET_ADDRESS,
             "--receive-address",
             MONERO_MAINNET_ADDRESS,
             "--seller",
@@ -806,8 +781,6 @@ mod tests {
             "--testnet",
             "--debug",
             "buy-xmr",
-            "--change-address",
-            BITCOIN_TESTNET_ADDRESS,
             "--receive-address",
             MONERO_STAGENET_ADDRESS,
             "--seller",
@@ -850,8 +823,6 @@ mod tests {
             BINARY_NAME,
             "--json",
             "buy-xmr",
-            "--change-address",
-            BITCOIN_MAINNET_ADDRESS,
             "--receive-address",
             MONERO_MAINNET_ADDRESS,
             "--seller",
@@ -869,8 +840,6 @@ mod tests {
             "--testnet",
             "--json",
             "buy-xmr",
-            "--change-address",
-            BITCOIN_TESTNET_ADDRESS,
             "--receive-address",
             MONERO_STAGENET_ADDRESS,
             "--seller",
@@ -919,7 +888,6 @@ mod tests {
                     bitcoin_electrum_rpc_url: Url::from_str(DEFAULT_ELECTRUM_RPC_URL_TESTNET)
                         .unwrap(),
                     bitcoin_target_block: DEFAULT_BITCOIN_CONFIRMATION_TARGET_TESTNET,
-                    bitcoin_change_address: BITCOIN_TESTNET_ADDRESS.parse().unwrap(),
                     monero_receive_address: monero::Address::from_str(MONERO_STAGENET_ADDRESS)
                         .unwrap(),
                     monero_daemon_address: DEFAULT_MONERO_DAEMON_ADDRESS_STAGENET.to_string(),
@@ -938,7 +906,6 @@ mod tests {
                     seller: Multiaddr::from_str(MULTI_ADDRESS).unwrap(),
                     bitcoin_electrum_rpc_url: Url::from_str(DEFAULT_ELECTRUM_RPC_URL).unwrap(),
                     bitcoin_target_block: DEFAULT_BITCOIN_CONFIRMATION_TARGET,
-                    bitcoin_change_address: BITCOIN_MAINNET_ADDRESS.parse().unwrap(),
                     monero_receive_address: monero::Address::from_str(MONERO_MAINNET_ADDRESS)
                         .unwrap(),
                     monero_daemon_address: DEFAULT_MONERO_DAEMON_ADDRESS.to_string(),

swap/src/database/bob.rs

@@ -3,17 +3,13 @@ use crate::protocol::bob;
 use crate::protocol::bob::BobState;
 use monero_rpc::wallet::BlockHeight;
 use serde::{Deserialize, Serialize};
-use serde_with::{serde_as, DisplayFromStr};
 use std::fmt;
 
-#[serde_as]
 #[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
 pub enum Bob {
     Started {
         #[serde(with = "::bitcoin::util::amount::serde::as_sat")]
         btc_amount: bitcoin::Amount,
-        #[serde_as(as = "DisplayFromStr")]
-        change_address: bitcoin::Address,
     },
     ExecutionSetupDone {
         state2: bob::State2,
@@ -49,13 +45,7 @@ pub enum BobEndState {
 impl From<BobState> for Bob {
     fn from(bob_state: BobState) -> Self {
         match bob_state {
-            BobState::Started {
+            BobState::Started { btc_amount } => Bob::Started { btc_amount },
-                btc_amount,
-                change_address,
-            } => Bob::Started {
-                btc_amount,
-                change_address,
-            },
             BobState::SwapSetupCompleted(state2) => Bob::ExecutionSetupDone { state2 },
             BobState::BtcLocked(state3) => Bob::BtcLocked { state3 },
             BobState::XmrLockProofReceived {
@@ -87,13 +77,7 @@ impl From<BobState> for Bob {
 impl From<Bob> for BobState {
     fn from(db_state: Bob) -> Self {
         match db_state {
-            Bob::Started {
+            Bob::Started { btc_amount } => BobState::Started { btc_amount },
-                btc_amount,
-                change_address,
-            } => BobState::Started {
-                btc_amount,
-                change_address,
-            },
             Bob::ExecutionSetupDone { state2 } => BobState::SwapSetupCompleted(state2),
             Bob::BtcLocked { state3 } => BobState::BtcLocked(state3),
             Bob::XmrLockProofReceived {

swap/src/protocol/bob.rs

@@ -33,14 +33,10 @@ impl Swap {
         env_config: env::Config,
         event_loop_handle: cli::EventLoopHandle,
         monero_receive_address: monero::Address,
-        bitcoin_change_address: bitcoin::Address,
         btc_amount: bitcoin::Amount,
     ) -> Self {
         Self {
-            state: BobState::Started {
+            state: BobState::Started { btc_amount },
-                btc_amount,
-                change_address: bitcoin_change_address,
-            },
             event_loop_handle,
             db,
             bitcoin_wallet,
@@ -51,7 +47,6 @@ impl Swap {
         }
     }
 
-    #[allow(clippy::too_many_arguments)]
     pub fn from_db(
         db: Database,
         id: Uuid,

swap/src/protocol/bob/state.rs

@@ -25,7 +25,6 @@ use uuid::Uuid;
 pub enum BobState {
     Started {
         btc_amount: bitcoin::Amount,
-        change_address: bitcoin::Address,
     },
     SwapSetupCompleted(State2),
     BtcLocked(State3),
@@ -170,14 +169,7 @@ impl State0 {
             bail!("Alice's dleq proof doesn't verify")
         }
 
-        let tx_lock = bitcoin::TxLock::new(
+        let tx_lock = bitcoin::TxLock::new(wallet, self.btc, msg.A, self.b.public()).await?;
-            wallet,
-            self.btc,
-            msg.A,
-            self.b.public(),
-            self.refund_address.clone(),
-        )
-        .await?;
         let v = msg.v_a + self.v_b;
 
         Ok(State1 {

swap/src/protocol/bob/swap.rs

@@ -61,10 +61,8 @@ async fn next_state(
     tracing::trace!(%state, "Advancing state");
 
     Ok(match state {
-        BobState::Started {
+        BobState::Started { btc_amount } => {
-            btc_amount,
+            let bitcoin_refund_address = bitcoin_wallet.new_address().await?;
-            change_address,
-        } => {
             let tx_refund_fee = bitcoin_wallet
                 .estimate_fee(TxRefund::weight(), btc_amount)
                 .await?;
@@ -78,7 +76,7 @@ async fn next_state(
                     btc: btc_amount,
                     tx_refund_fee,
                     tx_cancel_fee,
-                    bitcoin_refund_address: change_address,
+                    bitcoin_refund_address,
                 })
                 .await?;
 

swap/tests/harness/mod.rs

@@ -434,7 +434,6 @@ impl BobParams {
             self.env_config,
             handle,
             self.monero_wallet.get_main_address(),
-            self.bitcoin_wallet.new_address().await?,
             btc_amount,
         );