Merge pull request #36 from comit-network/recovery

Recover from a failed swap

.gitignore

@@ -1,4 +1,3 @@
-
 # Created by https://www.toptal.com/developers/gitignore/api/rust,clion+all,emacs
 # Edit at https://www.toptal.com/developers/gitignore?templates=rust,clion+all,emacs
 
@@ -154,4 +153,7 @@ Cargo.lock
 # These are backup files generated by rustfmt
 **/*.rs.bk
 
+# sled DB directory generated during local development
+.swap-db/
+
 # End of https://www.toptal.com/developers/gitignore/api/rust,clion+all,emacs

swap/Cargo.toml

@@ -14,19 +14,22 @@ base64 = "0.12"
 bitcoin = { version = "0.23", features = ["rand", "use-serde"] } # TODO: Upgrade other crates in this repo to use this version.
 bitcoin-harness = { git = "https://github.com/coblox/bitcoin-harness-rs", rev = "3be644cd9512c157d3337a189298b8257ed54d04" }
 derivative = "2"
+ecdsa_fun = { git = "https://github.com/LLFourn/secp256kfun", rev = "510d48ef6a2b19805f7f5c70c598e5b03f668e7a", features = ["libsecp_compat", "serde", "serialization"] }
 futures = { version = "0.3", default-features = false }
 genawaiter = "0.99.1"
 libp2p = { version = "0.29", default-features = false, features = ["tcp-tokio", "yamux", "mplex", "dns", "noise", "request-response"] }
 libp2p-tokio-socks5 = "0.4"
 log = { version = "0.4", features = ["serde"] }
-monero = "0.9"
+monero = { version = "0.9", features = ["serde_support"] }
 monero-harness = { path = "../monero-harness" }
+prettytable-rs = "0.8"
 rand = "0.7"
 reqwest = { version = "0.10", default-features = false, features = ["socks"] }
 serde = { version = "1", features = ["derive"] }
 serde_cbor = "0.11"
 serde_derive = "1.0"
 serde_json = "1"
+sha2 = "0.9"
 sled = "0.34"
 structopt = "0.3"
 tempfile = "3"
@@ -39,6 +42,7 @@ tracing-futures = { version = "0.2", features = ["std-future", "futures-03"] }
 tracing-log = "0.1"
 tracing-subscriber = { version = "0.2", default-features = false, features = ["fmt", "ansi", "env-filter"] }
 url = "2.1"
+uuid = { version = "0.8", features = ["serde", "v4"] }
 void = "1"
 xmr-btc = { path = "../xmr-btc" }
 

swap/src/alice.rs

@@ -13,6 +13,7 @@ use rand::rngs::OsRng;
 use std::{sync::Arc, time::Duration};
 use tokio::sync::Mutex;
 use tracing::{debug, info, warn};
+use uuid::Uuid;
 
 mod amounts;
 mod message0;
@@ -31,6 +32,8 @@ use crate::{
         transport::SwapTransport,
         TokioExecutor,
     },
+    state,
+    storage::Database,
     SwapAmounts, PUNISH_TIMELOCK, REFUND_TIMELOCK,
 };
 use xmr_btc::{
@@ -43,6 +46,7 @@ use xmr_btc::{
 pub async fn swap(
     bitcoin_wallet: Arc<bitcoin::Wallet>,
     monero_wallet: Arc<monero::Wallet>,
+    db: Database,
     listen: Multiaddr,
     transport: SwapTransport,
     behaviour: Alice,
@@ -71,7 +75,7 @@ pub async fn swap(
     // to `ConstantBackoff`.
     #[async_trait]
     impl ReceiveBitcoinRedeemEncsig for Network {
-        async fn receive_bitcoin_redeem_encsig(&mut self) -> xmr_btc::bitcoin::EncryptedSignature {
+        async fn receive_bitcoin_redeem_encsig(&mut self) -> bitcoin::EncryptedSignature {
             #[derive(Debug)]
             struct UnexpectedMessage;
 
@@ -173,6 +177,10 @@ pub async fn swap(
         other => panic!("Unexpected event: {:?}", other),
     };
 
+    let swap_id = Uuid::new_v4();
+    db.insert_latest_state(swap_id, state::Alice::Handshaken(state3.clone()).into())
+        .await?;
+
     info!("Handshake complete, we now have State3 for Alice.");
 
     let network = Arc::new(Mutex::new(Network {
@@ -183,7 +191,7 @@ pub async fn swap(
     let mut action_generator = action_generator(
         network.clone(),
         bitcoin_wallet.clone(),
-        state3,
+        state3.clone(),
         TX_LOCK_MINE_TIMEOUT,
     );
 
@@ -198,33 +206,68 @@ pub async fn swap(
                 public_spend_key,
                 public_view_key,
             }) => {
+                db.insert_latest_state(swap_id, state::Alice::BtcLocked(state3.clone()).into())
+                    .await?;
+
                 let (transfer_proof, _) = monero_wallet
                     .transfer(public_spend_key, public_view_key, amount)
                     .await?;
 
+                db.insert_latest_state(swap_id, state::Alice::XmrLocked(state3.clone()).into())
+                    .await?;
+
                 let mut guard = network.as_ref().lock().await;
                 guard.send_message2(transfer_proof).await;
                 info!("Sent transfer proof");
             }
 
             GeneratorState::Yielded(Action::RedeemBtc(tx)) => {
+                db.insert_latest_state(
+                    swap_id,
+                    state::Alice::BtcRedeemable {
+                        state: state3.clone(),
+                        redeem_tx: tx.clone(),
+                    }
+                    .into(),
+                )
+                .await?;
+
                 let _ = bitcoin_wallet.broadcast_signed_transaction(tx).await?;
             }
             GeneratorState::Yielded(Action::CancelBtc(tx)) => {
                 let _ = bitcoin_wallet.broadcast_signed_transaction(tx).await?;
             }
             GeneratorState::Yielded(Action::PunishBtc(tx)) => {
+                db.insert_latest_state(swap_id, state::Alice::BtcPunishable(state3.clone()).into())
+                    .await?;
+
                 let _ = bitcoin_wallet.broadcast_signed_transaction(tx).await?;
             }
             GeneratorState::Yielded(Action::CreateMoneroWalletForOutput {
                 spend_key,
                 view_key,
             }) => {
+                db.insert_latest_state(
+                    swap_id,
+                    state::Alice::BtcRefunded {
+                        state: state3.clone(),
+                        spend_key,
+                        view_key,
+                    }
+                    .into(),
+                )
+                .await?;
+
                 monero_wallet
                     .create_and_load_wallet_for_output(spend_key, view_key)
                     .await?;
             }
-            GeneratorState::Complete(()) => return Ok(()),
+            GeneratorState::Complete(()) => {
+                db.insert_latest_state(swap_id, state::Alice::SwapComplete.into())
+                    .await?;
+
+                return Ok(());
+            }
         }
     }
 }

swap/src/bitcoin.rs

@@ -8,13 +8,13 @@ use bitcoin_harness::bitcoind_rpc::PsbtBase64;
 use reqwest::Url;
 use tokio::time;
 use xmr_btc::bitcoin::{
-    Amount, BlockHeight, BroadcastSignedTransaction, BuildTxLockPsbt, SignTxLock,
+    BlockHeight, BroadcastSignedTransaction, BuildTxLockPsbt, SignTxLock, TransactionBlockHeight,
-    TransactionBlockHeight, TxLock, Txid, WatchForRawTransaction,
+    WatchForRawTransaction,
 };
 
-pub const TX_LOCK_MINE_TIMEOUT: u64 = 3600;
+pub use xmr_btc::bitcoin::*;
 
-// This is cut'n'paste from xmr_btc/tests/harness/wallet/bitcoin.rs
+pub const TX_LOCK_MINE_TIMEOUT: u64 = 3600;
 
 #[derive(Debug)]
 pub struct Wallet(pub bitcoin_harness::Wallet);

swap/src/bob.rs

@@ -13,6 +13,7 @@ use rand::rngs::OsRng;
 use std::{process, sync::Arc, time::Duration};
 use tokio::sync::Mutex;
 use tracing::{debug, info, warn};
+use uuid::Uuid;
 
 mod amounts;
 mod message0;
@@ -22,14 +23,15 @@ mod message3;
 
 use self::{amounts::*, message0::*, message1::*, message2::*, message3::*};
 use crate::{
-    bitcoin,
+    bitcoin::{self, TX_LOCK_MINE_TIMEOUT},
-    bitcoin::TX_LOCK_MINE_TIMEOUT,
     monero,
     network::{
         peer_tracker::{self, PeerTracker},
         transport::SwapTransport,
         TokioExecutor,
     },
+    state,
+    storage::Database,
     Cmd, Rsp, SwapAmounts, PUNISH_TIMELOCK, REFUND_TIMELOCK,
 };
 use xmr_btc::{
@@ -43,6 +45,7 @@ use xmr_btc::{
 pub async fn swap(
     bitcoin_wallet: Arc<bitcoin::Wallet>,
     monero_wallet: Arc<monero::Wallet>,
+    db: Database,
     btc: u64,
     addr: Multiaddr,
     mut cmd_tx: Sender<Cmd>,
@@ -141,6 +144,10 @@ pub async fn swap(
         other => panic!("unexpected event: {:?}", other),
     };
 
+    let swap_id = Uuid::new_v4();
+    db.insert_latest_state(swap_id, state::Bob::Handshaken(state2.clone()).into())
+        .await?;
+
     swarm.send_message2(alice.clone(), state2.next_message());
 
     info!("Handshake complete");
@@ -151,7 +158,7 @@ pub async fn swap(
         network.clone(),
         monero_wallet.clone(),
         bitcoin_wallet.clone(),
-        state2,
+        state2.clone(),
         TX_LOCK_MINE_TIMEOUT,
     );
 
@@ -160,20 +167,29 @@ pub async fn swap(
 
         info!("Resumed execution of generator, got: {:?}", state);
 
+        // TODO: Protect against transient errors
+        // TODO: Ignore transaction-already-in-block-chain errors
+
         match state {
             GeneratorState::Yielded(bob::Action::LockBtc(tx_lock)) => {
                 let signed_tx_lock = bitcoin_wallet.sign_tx_lock(tx_lock).await?;
                 let _ = bitcoin_wallet
                     .broadcast_signed_transaction(signed_tx_lock)
                     .await?;
+                db.insert_latest_state(swap_id, state::Bob::BtcLocked(state2.clone()).into())
+                    .await?;
             }
             GeneratorState::Yielded(bob::Action::SendBtcRedeemEncsig(tx_redeem_encsig)) => {
+                db.insert_latest_state(swap_id, state::Bob::XmrLocked(state2.clone()).into())
+                    .await?;
+
                 let mut guard = network.as_ref().lock().await;
                 guard.0.send_message3(alice.clone(), tx_redeem_encsig);
                 info!("Sent Bitcoin redeem encsig");
 
-                // TODO: Does Bob need to wait for Alice to send an empty response, or can we
+                // FIXME: Having to wait for Alice's response here is a big problem, because
-                // just continue?
+                // we're stuck if she doesn't send her response back. I believe this is
+                // currently necessary, so we may have to rework this and/or how we use libp2p
                 match guard.0.next().shared().await {
                     OutEvent::Message3 => {
                         debug!("Got Message3 empty response");
@@ -185,21 +201,35 @@ pub async fn swap(
                 spend_key,
                 view_key,
             }) => {
+                db.insert_latest_state(swap_id, state::Bob::BtcRedeemed(state2.clone()).into())
+                    .await?;
+
                 monero_wallet
                     .create_and_load_wallet_for_output(spend_key, view_key)
                     .await?;
             }
             GeneratorState::Yielded(bob::Action::CancelBtc(tx_cancel)) => {
+                db.insert_latest_state(swap_id, state::Bob::BtcRefundable(state2.clone()).into())
+                    .await?;
+
                 let _ = bitcoin_wallet
                     .broadcast_signed_transaction(tx_cancel)
                     .await?;
             }
             GeneratorState::Yielded(bob::Action::RefundBtc(tx_refund)) => {
+                db.insert_latest_state(swap_id, state::Bob::BtcRefundable(state2.clone()).into())
+                    .await?;
+
                 let _ = bitcoin_wallet
                     .broadcast_signed_transaction(tx_refund)
                     .await?;
             }
-            GeneratorState::Complete(()) => return Ok(()),
+            GeneratorState::Complete(()) => {
+                db.insert_latest_state(swap_id, state::Bob::SwapComplete.into())
+                    .await?;
+
+                return Ok(());
+            }
         }
     }
 }

swap/src/cli.rs

@@ -1,5 +1,6 @@
 use libp2p::core::Multiaddr;
 use url::Url;
+use uuid::Uuid;
 
 #[derive(structopt::StructOpt, Debug)]
 #[structopt(name = "xmr-btc-swap", about = "Trustless XMR BTC swaps")]
@@ -8,7 +9,7 @@ pub enum Options {
         #[structopt(default_value = "http://127.0.0.1:8332", long = "bitcoind")]
         bitcoind_url: Url,
 
-        #[structopt(default_value = "http://127.0.0.1:18083", long = "monerod")]
+        #[structopt(default_value = "http://127.0.0.1:18083/json_rpc", long = "monerod")]
         monerod_url: Url,
 
         #[structopt(default_value = "/ip4/127.0.0.1/tcp/9876", long = "listen-addr")]
@@ -27,10 +28,21 @@ pub enum Options {
         #[structopt(default_value = "http://127.0.0.1:8332", long = "bitcoind")]
         bitcoind_url: Url,
 
-        #[structopt(default_value = "http://127.0.0.1:18083", long = "monerod")]
+        #[structopt(default_value = "http://127.0.0.1:18083/json_rpc", long = "monerod")]
         monerod_url: Url,
 
         #[structopt(long = "tor")]
         tor: bool,
     },
+    History,
+    Recover {
+        #[structopt(required = true)]
+        swap_id: Uuid,
+
+        #[structopt(default_value = "http://127.0.0.1:8332", long = "bitcoind")]
+        bitcoind_url: Url,
+
+        #[structopt(default_value = "http://127.0.0.1:18083/json_rpc", long = "monerod")]
+        monerod_url: Url,
+    },
 }

swap/src/lib.rs

@@ -6,6 +6,8 @@ pub mod bitcoin;
 pub mod bob;
 pub mod monero;
 pub mod network;
+pub mod recover;
+pub mod state;
 pub mod storage;
 pub mod tor;
 
@@ -32,10 +34,10 @@ pub enum Rsp {
 pub struct SwapAmounts {
     /// Amount of BTC to swap.
     #[serde(with = "::bitcoin::util::amount::serde::as_sat")]
-    pub btc: ::bitcoin::Amount,
+    pub btc: bitcoin::Amount,
     /// Amount of XMR to swap.
     #[serde(with = "xmr_btc::serde::monero_amount")]
-    pub xmr: xmr_btc::monero::Amount,
+    pub xmr: monero::Amount,
 }
 
 // TODO: Display in XMR and BTC (not picos and sats).

swap/src/main.rs

@@ -16,23 +16,28 @@ use anyhow::Result;
 use futures::{channel::mpsc, StreamExt};
 use libp2p::Multiaddr;
 use log::LevelFilter;
+use prettytable::{row, Table};
 use std::{io, io::Write, process, sync::Arc};
 use structopt::StructOpt;
 use swap::{
-    alice,
+    alice::{self, Alice},
-    alice::Alice,
+    bitcoin,
-    bitcoin, bob,
+    bob::{self, Bob},
-    bob::Bob,
     monero,
     network::transport::{build, build_tor, SwapTransport},
+    recover::recover,
     Cmd, Rsp, SwapAmounts,
 };
 use tracing::info;
 
+#[macro_use]
+extern crate prettytable;
+
 mod cli;
 mod trace;
 
 use cli::Options;
+use swap::storage::Database;
 
 // TODO: Add root seed file instead of generating new seed each run.
 
@@ -42,6 +47,9 @@ async fn main() -> Result<()> {
 
     trace::init_tracing(LevelFilter::Debug)?;
 
+    // This currently creates the directory if it's not there in the first place
+    let db = Database::open(std::path::Path::new("./.swap-db/")).unwrap();
+
     match opt {
         Options::Alice {
             bitcoind_url,
@@ -83,6 +91,7 @@ async fn main() -> Result<()> {
             swap_as_alice(
                 bitcoin_wallet,
                 monero_wallet,
+                db,
                 listen_addr,
                 transport,
                 behaviour,
@@ -116,6 +125,7 @@ async fn main() -> Result<()> {
             swap_as_bob(
                 bitcoin_wallet,
                 monero_wallet,
+                db,
                 satoshis,
                 alice_addr,
                 transport,
@@ -123,6 +133,31 @@ async fn main() -> Result<()> {
             )
             .await?;
         }
+        Options::History => {
+            let mut table = Table::new();
+
+            table.add_row(row!["SWAP ID", "STATE"]);
+
+            for (swap_id, state) in db.all()? {
+                table.add_row(row![swap_id, state]);
+            }
+
+            // Print the table to stdout
+            table.printstd();
+        }
+        Options::Recover {
+            swap_id,
+            bitcoind_url,
+            monerod_url,
+        } => {
+            let state = db.get_state(swap_id)?;
+            let bitcoin_wallet = bitcoin::Wallet::new("bob", bitcoind_url)
+                .await
+                .expect("failed to create bitcoin wallet");
+            let monero_wallet = monero::Wallet::new(monerod_url);
+
+            recover(bitcoin_wallet, monero_wallet, state).await?;
+        }
     }
 
     Ok(())
@@ -149,16 +184,26 @@ async fn create_tor_service(
 async fn swap_as_alice(
     bitcoin_wallet: Arc<swap::bitcoin::Wallet>,
     monero_wallet: Arc<swap::monero::Wallet>,
+    db: Database,
     addr: Multiaddr,
     transport: SwapTransport,
     behaviour: Alice,
 ) -> Result<()> {
-    alice::swap(bitcoin_wallet, monero_wallet, addr, transport, behaviour).await
+    alice::swap(
+        bitcoin_wallet,
+        monero_wallet,
+        db,
+        addr,
+        transport,
+        behaviour,
+    )
+    .await
 }
 
 async fn swap_as_bob(
     bitcoin_wallet: Arc<swap::bitcoin::Wallet>,
     monero_wallet: Arc<swap::monero::Wallet>,
+    db: Database,
     sats: u64,
     alice: Multiaddr,
     transport: SwapTransport,
@@ -169,6 +214,7 @@ async fn swap_as_bob(
     tokio::spawn(bob::swap(
         bitcoin_wallet,
         monero_wallet,
+        db,
         sats,
         alice,
         cmd_tx,

swap/src/monero.rs

@@ -1,15 +1,11 @@
 use anyhow::Result;
 use async_trait::async_trait;
 use backoff::{backoff::Constant as ConstantBackoff, future::FutureOperation as _};
-use monero::{Address, Network, PrivateKey};
 use monero_harness::rpc::wallet;
 use std::{str::FromStr, time::Duration};
-
 use url::Url;
-pub use xmr_btc::monero::{
+
-    Amount, CreateWalletForOutput, InsufficientFunds, PrivateViewKey, PublicKey, PublicViewKey,
+pub use xmr_btc::monero::*;
-    Transfer, TransferProof, TxHash, WatchForTransfer, *,
-};
 
 pub struct Wallet(pub wallet::Client);
 

swap/src/recover.rs

@@ -0,0 +1,481 @@
+//! This module is used to attempt to recover an unfinished swap.
+//!
+//! Recovery is only supported for certain states and the strategy followed is
+//! to perform the simplest steps that require no further action from the
+//! counterparty.
+//!
+//! The quality of this module is bad because there is a lot of code
+//! duplication, both within the module and with respect to
+//! `xmr_btc/src/{alice,bob}.rs`. In my opinion, a better approach to support
+//! swap recovery would be through the `action_generator`s themselves, but this
+//! was deemed too complicated for the time being.
+
+use crate::{
+    bitcoin, monero,
+    monero::CreateWalletForOutput,
+    state::{Alice, Bob, Swap},
+};
+use anyhow::Result;
+use ecdsa_fun::{adaptor::Adaptor, nonce::Deterministic};
+use futures::{
+    future::{select, Either},
+    pin_mut,
+};
+use sha2::Sha256;
+use tracing::info;
+use xmr_btc::bitcoin::{
+    poll_until_block_height_is_gte, BroadcastSignedTransaction, TransactionBlockHeight,
+    WatchForRawTransaction,
+};
+
+pub async fn recover(
+    bitcoin_wallet: bitcoin::Wallet,
+    monero_wallet: monero::Wallet,
+    state: Swap,
+) -> Result<()> {
+    match state {
+        Swap::Alice(state) => alice_recover(bitcoin_wallet, monero_wallet, state).await,
+        Swap::Bob(state) => bob_recover(bitcoin_wallet, monero_wallet, state).await,
+    }
+}
+
+pub async fn alice_recover(
+    bitcoin_wallet: bitcoin::Wallet,
+    monero_wallet: monero::Wallet,
+    state: Alice,
+) -> Result<()> {
+    match state {
+        Alice::Handshaken(_) | Alice::BtcLocked(_) | Alice::SwapComplete => {
+            info!("Nothing to do");
+        }
+        Alice::XmrLocked(state) => {
+            info!("Monero still locked up");
+
+            let tx_cancel = bitcoin::TxCancel::new(
+                &state.tx_lock,
+                state.refund_timelock,
+                state.a.public(),
+                state.B.clone(),
+            );
+
+            info!("Checking if the Bitcoin cancel transaction has been published");
+            if bitcoin_wallet
+                .0
+                .get_raw_transaction(tx_cancel.txid())
+                .await
+                .is_err()
+            {
+                info!("Bitcoin cancel transaction not yet published");
+
+                let tx_lock_height = bitcoin_wallet
+                    .transaction_block_height(state.tx_lock.txid())
+                    .await;
+                poll_until_block_height_is_gte(
+                    &bitcoin_wallet,
+                    tx_lock_height + state.refund_timelock,
+                )
+                .await;
+
+                let sig_a = state.a.sign(tx_cancel.digest());
+                let sig_b = state.tx_cancel_sig_bob.clone();
+
+                let tx_cancel = tx_cancel
+                    .clone()
+                    .add_signatures(
+                        &state.tx_lock,
+                        (state.a.public(), sig_a),
+                        (state.B.clone(), sig_b),
+                    )
+                    .expect("sig_{a,b} to be valid signatures for tx_cancel");
+
+                // TODO: We should not fail if the transaction is already on the blockchain
+                bitcoin_wallet
+                    .broadcast_signed_transaction(tx_cancel)
+                    .await?;
+            }
+
+            info!("Confirmed that Bitcoin cancel transaction is on the blockchain");
+
+            let tx_cancel_height = bitcoin_wallet
+                .transaction_block_height(tx_cancel.txid())
+                .await;
+            let poll_until_bob_can_be_punished = poll_until_block_height_is_gte(
+                &bitcoin_wallet,
+                tx_cancel_height + state.punish_timelock,
+            );
+            pin_mut!(poll_until_bob_can_be_punished);
+
+            let tx_refund = bitcoin::TxRefund::new(&tx_cancel, &state.refund_address);
+
+            info!("Waiting for either Bitcoin refund or punish timelock");
+            match select(
+                bitcoin_wallet.watch_for_raw_transaction(tx_refund.txid()),
+                poll_until_bob_can_be_punished,
+            )
+            .await
+            {
+                Either::Left((tx_refund_published, ..)) => {
+                    info!("Found Bitcoin refund transaction");
+
+                    let s_a = monero::PrivateKey {
+                        scalar: state.s_a.into_ed25519(),
+                    };
+
+                    let tx_refund_sig = tx_refund
+                        .extract_signature_by_key(tx_refund_published, state.a.public())?;
+                    let tx_refund_encsig = state
+                        .a
+                        .encsign(state.S_b_bitcoin.clone(), tx_refund.digest());
+
+                    let s_b = bitcoin::recover(state.S_b_bitcoin, tx_refund_sig, tx_refund_encsig)?;
+                    let s_b = monero::PrivateKey::from_scalar(
+                        monero::Scalar::from_bytes_mod_order(s_b.to_bytes()),
+                    );
+
+                    monero_wallet
+                        .create_and_load_wallet_for_output(s_a + s_b, state.v)
+                        .await?;
+                    info!("Successfully refunded monero");
+                }
+                Either::Right(_) => {
+                    info!("Punish timelock reached, attempting to punish Bob");
+
+                    let tx_punish = bitcoin::TxPunish::new(
+                        &tx_cancel,
+                        &state.punish_address,
+                        state.punish_timelock,
+                    );
+
+                    let sig_a = state.a.sign(tx_punish.digest());
+                    let sig_b = state.tx_punish_sig_bob.clone();
+
+                    let sig_tx_punish = tx_punish.add_signatures(
+                        &tx_cancel,
+                        (state.a.public(), sig_a),
+                        (state.B.clone(), sig_b),
+                    )?;
+
+                    bitcoin_wallet
+                        .broadcast_signed_transaction(sig_tx_punish)
+                        .await?;
+                    info!("Successfully punished Bob's inactivity by taking bitcoin");
+                }
+            };
+        }
+        Alice::BtcRedeemable { redeem_tx, state } => {
+            info!("Have the means to redeem the Bitcoin");
+
+            let tx_lock_height = bitcoin_wallet
+                .transaction_block_height(state.tx_lock.txid())
+                .await;
+
+            let block_height = bitcoin_wallet.0.block_height().await?;
+            let refund_absolute_expiry = tx_lock_height + state.refund_timelock;
+
+            info!("Checking refund timelock");
+            if block_height < refund_absolute_expiry {
+                info!("Safe to redeem");
+
+                bitcoin_wallet
+                    .broadcast_signed_transaction(redeem_tx)
+                    .await?;
+                info!("Successfully redeemed bitcoin");
+            } else {
+                info!("Refund timelock reached");
+
+                let tx_cancel = bitcoin::TxCancel::new(
+                    &state.tx_lock,
+                    state.refund_timelock,
+                    state.a.public(),
+                    state.B.clone(),
+                );
+
+                info!("Checking if the Bitcoin cancel transaction has been published");
+                if bitcoin_wallet
+                    .0
+                    .get_raw_transaction(tx_cancel.txid())
+                    .await
+                    .is_err()
+                {
+                    let sig_a = state.a.sign(tx_cancel.digest());
+                    let sig_b = state.tx_cancel_sig_bob.clone();
+
+                    let tx_cancel = tx_cancel
+                        .clone()
+                        .add_signatures(
+                            &state.tx_lock,
+                            (state.a.public(), sig_a),
+                            (state.B.clone(), sig_b),
+                        )
+                        .expect("sig_{a,b} to be valid signatures for tx_cancel");
+
+                    // TODO: We should not fail if the transaction is already on the blockchain
+                    bitcoin_wallet
+                        .broadcast_signed_transaction(tx_cancel)
+                        .await?;
+                }
+
+                info!("Confirmed that Bitcoin cancel transaction is on the blockchain");
+
+                let tx_cancel_height = bitcoin_wallet
+                    .transaction_block_height(tx_cancel.txid())
+                    .await;
+                let poll_until_bob_can_be_punished = poll_until_block_height_is_gte(
+                    &bitcoin_wallet,
+                    tx_cancel_height + state.punish_timelock,
+                );
+                pin_mut!(poll_until_bob_can_be_punished);
+
+                let tx_refund = bitcoin::TxRefund::new(&tx_cancel, &state.refund_address);
+
+                info!("Waiting for either Bitcoin refund or punish timelock");
+                match select(
+                    bitcoin_wallet.watch_for_raw_transaction(tx_refund.txid()),
+                    poll_until_bob_can_be_punished,
+                )
+                .await
+                {
+                    Either::Left((tx_refund_published, ..)) => {
+                        info!("Found Bitcoin refund transaction");
+
+                        let s_a = monero::PrivateKey {
+                            scalar: state.s_a.into_ed25519(),
+                        };
+
+                        let tx_refund_sig = tx_refund
+                            .extract_signature_by_key(tx_refund_published, state.a.public())?;
+                        let tx_refund_encsig = state
+                            .a
+                            .encsign(state.S_b_bitcoin.clone(), tx_refund.digest());
+
+                        let s_b =
+                            bitcoin::recover(state.S_b_bitcoin, tx_refund_sig, tx_refund_encsig)?;
+                        let s_b = monero::PrivateKey::from_scalar(
+                            monero::Scalar::from_bytes_mod_order(s_b.to_bytes()),
+                        );
+
+                        monero_wallet
+                            .create_and_load_wallet_for_output(s_a + s_b, state.v)
+                            .await?;
+                        info!("Successfully refunded monero");
+                    }
+                    Either::Right(_) => {
+                        info!("Punish timelock reached, attempting to punish Bob");
+
+                        let tx_punish = bitcoin::TxPunish::new(
+                            &tx_cancel,
+                            &state.punish_address,
+                            state.punish_timelock,
+                        );
+
+                        let sig_a = state.a.sign(tx_punish.digest());
+                        let sig_b = state.tx_punish_sig_bob.clone();
+
+                        let sig_tx_punish = tx_punish.add_signatures(
+                            &tx_cancel,
+                            (state.a.public(), sig_a),
+                            (state.B.clone(), sig_b),
+                        )?;
+
+                        bitcoin_wallet
+                            .broadcast_signed_transaction(sig_tx_punish)
+                            .await?;
+                        info!("Successfully punished Bob's inactivity by taking bitcoin");
+                    }
+                };
+            }
+        }
+        Alice::BtcPunishable(state) => {
+            info!("Punish timelock reached, attempting to punish Bob");
+
+            let tx_cancel = bitcoin::TxCancel::new(
+                &state.tx_lock,
+                state.refund_timelock,
+                state.a.public(),
+                state.B.clone(),
+            );
+            let tx_refund = bitcoin::TxRefund::new(&tx_cancel, &state.refund_address);
+
+            info!("Checking if Bitcoin has already been refunded");
+
+            // TODO: Protect against transient errors so that we can correctly decide if the
+            // bitcoin has been refunded
+            match bitcoin_wallet.0.get_raw_transaction(tx_refund.txid()).await {
+                Ok(tx_refund_published) => {
+                    info!("Bitcoin already refunded");
+
+                    let s_a = monero::PrivateKey {
+                        scalar: state.s_a.into_ed25519(),
+                    };
+
+                    let tx_refund_sig = tx_refund
+                        .extract_signature_by_key(tx_refund_published, state.a.public())?;
+                    let tx_refund_encsig = state
+                        .a
+                        .encsign(state.S_b_bitcoin.clone(), tx_refund.digest());
+
+                    let s_b = bitcoin::recover(state.S_b_bitcoin, tx_refund_sig, tx_refund_encsig)?;
+                    let s_b = monero::PrivateKey::from_scalar(
+                        monero::Scalar::from_bytes_mod_order(s_b.to_bytes()),
+                    );
+
+                    monero_wallet
+                        .create_and_load_wallet_for_output(s_a + s_b, state.v)
+                        .await?;
+                    info!("Successfully refunded monero");
+                }
+                Err(_) => {
+                    info!("Bitcoin not yet refunded");
+
+                    let tx_punish = bitcoin::TxPunish::new(
+                        &tx_cancel,
+                        &state.punish_address,
+                        state.punish_timelock,
+                    );
+
+                    let sig_a = state.a.sign(tx_punish.digest());
+                    let sig_b = state.tx_punish_sig_bob.clone();
+
+                    let sig_tx_punish = tx_punish.add_signatures(
+                        &tx_cancel,
+                        (state.a.public(), sig_a),
+                        (state.B.clone(), sig_b),
+                    )?;
+
+                    bitcoin_wallet
+                        .broadcast_signed_transaction(sig_tx_punish)
+                        .await?;
+                    info!("Successfully punished Bob's inactivity by taking bitcoin");
+                }
+            }
+        }
+        Alice::BtcRefunded {
+            view_key,
+            spend_key,
+            ..
+        } => {
+            info!("Bitcoin was refunded, attempting to refund monero");
+
+            monero_wallet
+                .create_and_load_wallet_for_output(spend_key, view_key)
+                .await?;
+            info!("Successfully refunded monero");
+        }
+    };
+
+    Ok(())
+}
+
+pub async fn bob_recover(
+    bitcoin_wallet: crate::bitcoin::Wallet,
+    monero_wallet: crate::monero::Wallet,
+    state: Bob,
+) -> Result<()> {
+    match state {
+        Bob::Handshaken(_) | Bob::SwapComplete => {
+            info!("Nothing to do");
+        }
+        Bob::BtcLocked(state) | Bob::XmrLocked(state) | Bob::BtcRefundable(state) => {
+            info!("Bitcoin may still be locked up, attempting to refund");
+
+            let tx_cancel = bitcoin::TxCancel::new(
+                &state.tx_lock,
+                state.refund_timelock,
+                state.A.clone(),
+                state.b.public(),
+            );
+
+            info!("Checking if the Bitcoin cancel transaction has been published");
+            if bitcoin_wallet
+                .0
+                .get_raw_transaction(tx_cancel.txid())
+                .await
+                .is_err()
+            {
+                info!("Bitcoin cancel transaction not yet published");
+
+                let tx_lock_height = bitcoin_wallet
+                    .transaction_block_height(state.tx_lock.txid())
+                    .await;
+                poll_until_block_height_is_gte(
+                    &bitcoin_wallet,
+                    tx_lock_height + state.refund_timelock,
+                )
+                .await;
+
+                let sig_a = state.tx_cancel_sig_a.clone();
+                let sig_b = state.b.sign(tx_cancel.digest());
+
+                let tx_cancel = tx_cancel
+                    .clone()
+                    .add_signatures(
+                        &state.tx_lock,
+                        (state.A.clone(), sig_a),
+                        (state.b.public(), sig_b),
+                    )
+                    .expect("sig_{a,b} to be valid signatures for tx_cancel");
+
+                // TODO: We should not fail if the transaction is already on the blockchain
+                bitcoin_wallet
+                    .broadcast_signed_transaction(tx_cancel)
+                    .await?;
+            }
+
+            info!("Confirmed that Bitcoin cancel transaction is on the blockchain");
+
+            let tx_refund = bitcoin::TxRefund::new(&tx_cancel, &state.refund_address);
+            let signed_tx_refund = {
+                let adaptor = Adaptor::<Sha256, Deterministic<Sha256>>::default();
+                let sig_a = adaptor
+                    .decrypt_signature(&state.s_b.into_secp256k1(), state.tx_refund_encsig.clone());
+                let sig_b = state.b.sign(tx_refund.digest());
+
+                tx_refund
+                    .add_signatures(
+                        &tx_cancel,
+                        (state.A.clone(), sig_a),
+                        (state.b.public(), sig_b),
+                    )
+                    .expect("sig_{a,b} to be valid signatures for tx_refund")
+            };
+
+            // TODO: Check if Bitcoin has already been punished and provide a useful error
+            // message/log to the user if so
+            bitcoin_wallet
+                .broadcast_signed_transaction(signed_tx_refund)
+                .await?;
+            info!("Successfully refunded bitcoin");
+        }
+        Bob::BtcRedeemed(state) => {
+            info!("Bitcoin was redeemed, attempting to redeem monero");
+
+            let tx_redeem = bitcoin::TxRedeem::new(&state.tx_lock, &state.redeem_address);
+            let tx_redeem_published = bitcoin_wallet
+                .0
+                .get_raw_transaction(tx_redeem.txid())
+                .await?;
+
+            let tx_redeem_encsig = state
+                .b
+                .encsign(state.S_a_bitcoin.clone(), tx_redeem.digest());
+            let tx_redeem_sig =
+                tx_redeem.extract_signature_by_key(tx_redeem_published, state.b.public())?;
+
+            let s_a = bitcoin::recover(state.S_a_bitcoin, tx_redeem_sig, tx_redeem_encsig)?;
+            let s_a = monero::PrivateKey::from_scalar(monero::Scalar::from_bytes_mod_order(
+                s_a.to_bytes(),
+            ));
+
+            let s_b = monero::PrivateKey {
+                scalar: state.s_b.into_ed25519(),
+            };
+
+            monero_wallet
+                .create_and_load_wallet_for_output(s_a + s_b, state.v)
+                .await?;
+            info!("Successfully redeemed monero")
+        }
+    };
+
+    Ok(())
+}

swap/src/state.rs

@@ -0,0 +1,88 @@
+use serde::{Deserialize, Serialize};
+use std::fmt::Display;
+use xmr_btc::{alice, bob, monero, serde::monero_private_key};
+
+#[allow(clippy::large_enum_variant)]
+#[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
+pub enum Swap {
+    Alice(Alice),
+    Bob(Bob),
+}
+
+#[allow(clippy::large_enum_variant)]
+#[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
+pub enum Alice {
+    Handshaken(alice::State3),
+    BtcLocked(alice::State3),
+    XmrLocked(alice::State3),
+    BtcRedeemable {
+        state: alice::State3,
+        redeem_tx: bitcoin::Transaction,
+    },
+    BtcPunishable(alice::State3),
+    BtcRefunded {
+        state: alice::State3,
+        #[serde(with = "monero_private_key")]
+        spend_key: monero::PrivateKey,
+        view_key: monero::PrivateViewKey,
+    },
+    SwapComplete,
+}
+
+#[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
+pub enum Bob {
+    Handshaken(bob::State2),
+    BtcLocked(bob::State2),
+    XmrLocked(bob::State2),
+    BtcRedeemed(bob::State2),
+    BtcRefundable(bob::State2),
+    SwapComplete,
+}
+
+impl From<Alice> for Swap {
+    fn from(from: Alice) -> Self {
+        Swap::Alice(from)
+    }
+}
+
+impl From<Bob> for Swap {
+    fn from(from: Bob) -> Self {
+        Swap::Bob(from)
+    }
+}
+
+impl Display for Swap {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Swap::Alice(alice) => Display::fmt(alice, f),
+            Swap::Bob(bob) => Display::fmt(bob, f),
+        }
+    }
+}
+
+impl Display for Alice {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Alice::Handshaken(_) => f.write_str("Handshake complete"),
+            Alice::BtcLocked(_) => f.write_str("Bitcoin locked"),
+            Alice::XmrLocked(_) => f.write_str("Monero locked"),
+            Alice::BtcRedeemable { .. } => f.write_str("Bitcoin redeemable"),
+            Alice::BtcPunishable(_) => f.write_str("Bitcoin punishable"),
+            Alice::BtcRefunded { .. } => f.write_str("Monero refundable"),
+            Alice::SwapComplete => f.write_str("Swap complete"),
+        }
+    }
+}
+
+impl Display for Bob {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Bob::Handshaken(_) => f.write_str("Handshake complete"),
+            Bob::BtcLocked(_) | Bob::XmrLocked(_) | Bob::BtcRefundable(_) => {
+                f.write_str("Bitcoin refundable")
+            }
+            Bob::BtcRedeemed(_) => f.write_str("Monero redeemable"),
+            Bob::SwapComplete => f.write_str("Swap complete"),
+        }
+    }
+}

swap/src/storage.rs

@@ -1,62 +1,68 @@
-use anyhow::{anyhow, Context, Result};
+use crate::state::Swap;
+use anyhow::{anyhow, bail, Context, Result};
 use serde::{de::DeserializeOwned, Serialize};
 use std::path::Path;
+use uuid::Uuid;
 
-pub struct Database<T>
+pub struct Database(sled::Db);
-where
-    T: Serialize + DeserializeOwned,
-{
-    db: sled::Db,
-    _marker: std::marker::PhantomData<T>,
-}
-
-impl<T> Database<T>
-where
-    T: Serialize + DeserializeOwned,
-{
-    // TODO: serialize using lazy/one-time initlisation
-    const LAST_STATE_KEY: &'static str = "latest_state";
 
+impl Database {
     pub fn open(path: &Path) -> Result<Self> {
         let db =
             sled::open(path).with_context(|| format!("Could not open the DB at {:?}", path))?;
 
-        Ok(Database {
+        Ok(Database(db))
-            db,
-            _marker: Default::default(),
-        })
     }
 
-    pub async fn insert_latest_state(&self, state: &T) -> Result<()> {
+    pub async fn insert_latest_state(&self, swap_id: Uuid, state: Swap) -> Result<()> {
-        let key = serialize(&Self::LAST_STATE_KEY)?;
+        let key = serialize(&swap_id)?;
         let new_value = serialize(&state).context("Could not serialize new state value")?;
 
-        let old_value = self.db.get(&key)?;
+        let old_value = self.0.get(&key)?;
 
-        self.db
+        self.0
             .compare_and_swap(key, old_value, Some(new_value))
             .context("Could not write in the DB")?
             .context("Stored swap somehow changed, aborting saving")?;
 
         // TODO: see if this can be done through sled config
-        self.db
+        self.0
             .flush_async()
             .await
             .map(|_| ())
             .context("Could not flush db")
     }
 
-    pub fn get_latest_state(&self) -> anyhow::Result<T> {
+    pub fn get_state(&self, swap_id: Uuid) -> anyhow::Result<Swap> {
-        let key = serialize(&Self::LAST_STATE_KEY)?;
+        let key = serialize(&swap_id)?;
 
         let encoded = self
-            .db
+            .0
             .get(&key)?
             .ok_or_else(|| anyhow!("State does not exist {:?}", key))?;
 
         let state = deserialize(&encoded).context("Could not deserialize state")?;
         Ok(state)
     }
+
+    pub fn all(&self) -> Result<Vec<(Uuid, Swap)>> {
+        self.0
+            .iter()
+            .map(|item| match item {
+                Ok((key, value)) => {
+                    let swap_id = deserialize::<Uuid>(&key);
+                    let swap = deserialize::<Swap>(&value).context("failed to deserialize swap");
+
+                    match (swap_id, swap) {
+                        (Ok(swap_id), Ok(swap)) => Ok((swap_id, swap)),
+                        (Ok(_), Err(err)) => Err(err),
+                        _ => bail!("failed to deserialize swap"),
+                    }
+                }
+                Err(err) => Err(err).context("failed to retrieve swap from DB"),
+            })
+            .collect()
+    }
 }
 
 pub fn serialize<T>(t: &T) -> anyhow::Result<Vec<u8>>
@@ -75,86 +81,87 @@ where
 
 #[cfg(test)]
 mod tests {
-    #![allow(non_snake_case)]
+    use crate::state::{Alice, Bob};
-    use super::*;
-    use bitcoin::SigHash;
-    use rand::rngs::OsRng;
-    use serde::{Deserialize, Serialize};
-    use std::str::FromStr;
-    use xmr_btc::{cross_curve_dleq, monero, serde::monero_private_key};
 
-    #[derive(Debug, Serialize, Deserialize, PartialEq)]
+    use super::*;
-    pub struct TestState {
-        A: xmr_btc::bitcoin::PublicKey,
-        a: xmr_btc::bitcoin::SecretKey,
-        s_a: cross_curve_dleq::Scalar,
-        #[serde(with = "monero_private_key")]
-        s_b: monero::PrivateKey,
-        S_a_monero: ::monero::PublicKey,
-        S_a_bitcoin: xmr_btc::bitcoin::PublicKey,
-        v: xmr_btc::monero::PrivateViewKey,
-        #[serde(with = "::bitcoin::util::amount::serde::as_sat")]
-        btc: ::bitcoin::Amount,
-        xmr: xmr_btc::monero::Amount,
-        refund_timelock: u32,
-        refund_address: ::bitcoin::Address,
-        transaction: ::bitcoin::Transaction,
-        tx_punish_sig: xmr_btc::bitcoin::Signature,
-    }
 
     #[tokio::test]
-    async fn recover_state_from_db() {
+    async fn can_write_and_read_to_multiple_keys() {
         let db_dir = tempfile::tempdir().unwrap();
         let db = Database::open(db_dir.path()).unwrap();
 
-        let a = xmr_btc::bitcoin::SecretKey::new_random(&mut OsRng);
+        let state_1 = Swap::Alice(Alice::SwapComplete);
-        let s_a = cross_curve_dleq::Scalar::random(&mut OsRng);
+        let swap_id_1 = Uuid::new_v4();
-        let s_b = monero::PrivateKey::from_scalar(monero::Scalar::random(&mut OsRng));
+        db.insert_latest_state(swap_id_1, state_1.clone())
-        let v_a = xmr_btc::monero::PrivateViewKey::new_random(&mut OsRng);
+            .await
-        let S_a_monero = monero::PublicKey::from_private_key(&monero::PrivateKey {
+            .expect("Failed to save second state");
-            scalar: s_a.into_ed25519(),
-        });
-        let S_a_bitcoin = s_a.into_secp256k1().into();
-        let tx_punish_sig = a.sign(SigHash::default());
 
-        let state = TestState {
+        let state_2 = Swap::Bob(Bob::SwapComplete);
-            A: a.public(),
+        let swap_id_2 = Uuid::new_v4();
-            a,
+        db.insert_latest_state(swap_id_2, state_2.clone())
-            s_b,
+            .await
-            s_a,
+            .expect("Failed to save first state");
-            S_a_monero,
-            S_a_bitcoin,
-            v: v_a,
-            btc: ::bitcoin::Amount::from_sat(100),
-            xmr: xmr_btc::monero::Amount::from_piconero(1000),
-            refund_timelock: 0,
-            refund_address: ::bitcoin::Address::from_str("1L5wSMgerhHg8GZGcsNmAx5EXMRXSKR3He")
-                .unwrap(),
-            transaction: ::bitcoin::Transaction {
-                version: 0,
-                lock_time: 0,
-                input: vec![::bitcoin::TxIn::default()],
-                output: vec![::bitcoin::TxOut::default()],
-            },
-            tx_punish_sig,
-        };
 
-        db.insert_latest_state(&state)
+        let recovered_1 = db
+            .get_state(swap_id_1)
+            .expect("Failed to recover first state");
+
+        let recovered_2 = db
+            .get_state(swap_id_2)
+            .expect("Failed to recover second state");
+
+        assert_eq!(recovered_1, state_1);
+        assert_eq!(recovered_2, state_2);
+    }
+
+    #[tokio::test]
+    async fn can_write_twice_to_one_key() {
+        let db_dir = tempfile::tempdir().unwrap();
+        let db = Database::open(db_dir.path()).unwrap();
+
+        let state = Swap::Alice(Alice::SwapComplete);
+
+        let swap_id = Uuid::new_v4();
+        db.insert_latest_state(swap_id, state.clone())
             .await
             .expect("Failed to save state the first time");
-        let recovered: TestState = db
+        let recovered = db
-            .get_latest_state()
+            .get_state(swap_id)
             .expect("Failed to recover state the first time");
 
         // We insert and recover twice to ensure database implementation allows the
         // caller to write to an existing key
-        db.insert_latest_state(&recovered)
+        db.insert_latest_state(swap_id, recovered)
             .await
             .expect("Failed to save state the second time");
-        let recovered: TestState = db
+        let recovered = db
-            .get_latest_state()
+            .get_state(swap_id)
             .expect("Failed to recover state the second time");
 
-        assert_eq!(state, recovered);
+        assert_eq!(recovered, state);
+    }
+
+    #[tokio::test]
+    async fn can_fetch_all_keys() {
+        let db_dir = tempfile::tempdir().unwrap();
+        let db = Database::open(db_dir.path()).unwrap();
+
+        let state_1 = Swap::Alice(Alice::SwapComplete);
+        let swap_id_1 = Uuid::new_v4();
+        db.insert_latest_state(swap_id_1, state_1.clone())
+            .await
+            .expect("Failed to save second state");
+
+        let state_2 = Swap::Bob(Bob::SwapComplete);
+        let swap_id_2 = Uuid::new_v4();
+        db.insert_latest_state(swap_id_2, state_2.clone())
+            .await
+            .expect("Failed to save first state");
+
+        let swaps = db.all().unwrap();
+
+        assert_eq!(swaps.len(), 2);
+        assert!(swaps.contains(&(swap_id_1, state_1)));
+        assert!(swaps.contains(&(swap_id_2, state_2)));
     }
 }

swap/src/trace.rs

@@ -14,7 +14,10 @@ pub fn init_tracing(level: log::LevelFilter) -> anyhow::Result<()> {
 
     let is_terminal = atty::is(Stream::Stdout);
     let subscriber = FmtSubscriber::builder()
-        .with_env_filter(format!("swap={}", level))
+        .with_env_filter(format!(
+            "swap={},xmr_btc={},monero_harness={}",
+            level, level, level
+        ))
         .with_ansi(is_terminal)
         .finish();
 

swap/tests/e2e.rs

@@ -1,20 +1,23 @@
-#[cfg(not(feature = "tor"))]
+use bitcoin_harness::Bitcoind;
-mod e2e_test {
+use futures::{channel::mpsc, future::try_join};
-    use bitcoin_harness::Bitcoind;
+use libp2p::Multiaddr;
-    use futures::{channel::mpsc, future::try_join};
+use monero_harness::Monero;
-    use libp2p::Multiaddr;
+use std::sync::Arc;
-    use monero_harness::Monero;
+use swap::{alice, bob, network::transport::build, storage::Database};
-    use std::sync::Arc;
+use tempfile::tempdir;
-    use swap::{alice, bob, network::transport::build};
+use testcontainers::clients::Cli;
-    use testcontainers::clients::Cli;
+use xmr_btc::bitcoin;
-    use tracing_subscriber::util::SubscriberInitExt;
 
-    #[tokio::test]
+// NOTE: For some reason running these tests overflows the stack. In order to
-    async fn swap() {
+// mitigate this run them with:
+//
+//     RUST_MIN_STACK=100000000 cargo test
+
+#[tokio::test]
+async fn swap() {
+    use tracing_subscriber::util::SubscriberInitExt as _;
     let _guard = tracing_subscriber::fmt()
-        .with_env_filter(
+        .with_env_filter("swap=info,xmr_btc=info")
-            "swap=debug,xmr_btc=debug,hyper=off,reqwest=off,monero_harness=info,testcontainers=info,libp2p=debug",
-        )
         .with_ansi(false)
         .set_default();
 
@@ -24,6 +27,7 @@ mod e2e_test {
 
     let cli = Cli::default();
     let bitcoind = Bitcoind::new(&cli, "0.19.1").unwrap();
+    dbg!(&bitcoind.node_url);
     let _ = bitcoind.init(5).await;
 
     let btc = bitcoin::Amount::from_sat(1_000_000);
@@ -51,10 +55,8 @@ mod e2e_test {
         .await
         .unwrap();
 
-        let (monero, _container) = Monero::new(&cli, Some("swap_".to_string()), vec![
+    let (monero, _container) =
-            "alice".to_string(),
+        Monero::new(&cli, None, vec!["alice".to_string(), "bob".to_string()])
-            "bob".to_string(),
-        ])
             .await
             .unwrap();
     monero
@@ -69,14 +71,19 @@ mod e2e_test {
 
     let alice_behaviour = alice::Alice::default();
     let alice_transport = build(alice_behaviour.identity()).unwrap();
+
+    let db = Database::open(std::path::Path::new("../.swap-db/")).unwrap();
     let alice_swap = alice::swap(
         alice_btc_wallet.clone(),
         alice_xmr_wallet.clone(),
+        db,
         alice_multiaddr.clone(),
         alice_transport,
         alice_behaviour,
     );
 
+    let db_dir = tempdir().unwrap();
+    let db = Database::open(db_dir.path()).unwrap();
     let (cmd_tx, mut _cmd_rx) = mpsc::channel(1);
     let (mut rsp_tx, rsp_rx) = mpsc::channel(1);
     let bob_behaviour = bob::Bob::default();
@@ -84,6 +91,7 @@ mod e2e_test {
     let bob_swap = bob::swap(
         bob_btc_wallet.clone(),
         bob_xmr_wallet.clone(),
+        db,
         btc.as_sat(),
         alice_multiaddr,
         cmd_tx,
@@ -107,11 +115,10 @@ mod e2e_test {
 
     assert_eq!(
         btc_alice_final,
-            btc_alice + btc - bitcoin::Amount::from_sat(xmr_btc::bitcoin::TX_FEE)
+        btc_alice + btc - bitcoin::Amount::from_sat(bitcoin::TX_FEE)
     );
     assert!(btc_bob_final <= btc_bob - btc);
 
     assert!(xmr_alice_final.as_piconero() <= xmr_alice - xmr);
     assert_eq!(xmr_bob_final.as_piconero(), xmr_bob + xmr);
-    }
 }

swap/tests/tor.rs

@@ -13,7 +13,6 @@ mod tor_test {
         onion::TorSecretKeyV3,
         utils::{run_tor, AutoKillChild},
     };
-    use tracing_subscriber::util::SubscriberInitExt;
 
     async fn hello_world(
         _req: hyper::Request<hyper::Body>,
@@ -76,10 +75,6 @@ mod tor_test {
 
     #[tokio::test]
     async fn test_tor_control_port() -> Result<()> {
-        let _guard = tracing_subscriber::fmt()
-            .with_env_filter("info")
-            .set_default();
-
         // start tmp tor
         let (_child, control_port, proxy_port, _tmp_torrc) = run_tmp_tor()?;
 

xmr-btc/src/alice.rs

@@ -97,7 +97,7 @@ where
     #[derive(Debug)]
     enum SwapFailed {
         BeforeBtcLock(Reason),
-        AfterXmrLock { tx_lock_height: u32, reason: Reason },
+        AfterXmrLock(Reason),
     }
 
     /// Reason why the swap has failed.
@@ -114,9 +114,7 @@ where
 
     #[derive(Debug)]
     enum RefundFailed {
-        BtcPunishable {
+        BtcPunishable,
-            tx_cancel_was_published: bool,
-        },
         /// Could not find Alice's signature on the refund transaction witness
         /// stack.
         BtcRefundSignature,
@@ -167,12 +165,7 @@ where
                 .await
                 {
                     Either::Left((encsig, _)) => encsig,
-                    Either::Right(_) => {
+                    Either::Right(_) => return Err(SwapFailed::AfterXmrLock(Reason::BtcExpired)),
-                        return Err(SwapFailed::AfterXmrLock {
-                            reason: Reason::BtcExpired,
-                            tx_lock_height,
-                        })
-                    }
                 };
 
                 tracing::debug!("select returned redeem encsig from message");
@@ -191,10 +184,7 @@ where
                     &tx_redeem.digest(),
                     &tx_redeem_encsig,
                 )
-                .map_err(|_| SwapFailed::AfterXmrLock {
+                .map_err(|_| SwapFailed::AfterXmrLock(Reason::InvalidEncryptedSignature))?;
-                    reason: Reason::InvalidEncryptedSignature,
-                    tx_lock_height,
-                })?;
 
                 let sig_a = a.sign(tx_redeem.digest());
                 let sig_b =
@@ -217,12 +207,7 @@ where
             .await
             {
                 Either::Left(_) => {}
-                Either::Right(_) => {
+                Either::Right(_) => return Err(SwapFailed::AfterXmrLock(Reason::BtcExpired)),
-                    return Err(SwapFailed::AfterXmrLock {
-                        reason: Reason::BtcExpired,
-                        tx_lock_height,
-                    })
-                }
             };
 
             Ok(())
@@ -233,19 +218,8 @@ where
             error!("swap failed: {:?}", err);
         }
 
-        if let Err(SwapFailed::AfterXmrLock {
+        if let Err(SwapFailed::AfterXmrLock(Reason::BtcExpired)) = swap_result {
-            reason: Reason::BtcExpired,
-            tx_lock_height,
-        }) = swap_result
-        {
             let refund_result: Result<(), RefundFailed> = async {
-                let poll_until_bob_can_be_punished = poll_until_block_height_is_gte(
-                    bitcoin_client.as_ref(),
-                    tx_lock_height + refund_timelock + punish_timelock,
-                )
-                .shared();
-                pin_mut!(poll_until_bob_can_be_punished);
-
                 let tx_cancel =
                     bitcoin::TxCancel::new(&tx_lock, refund_timelock, a.public(), B.clone());
                 let signed_tx_cancel = {
@@ -260,19 +234,19 @@ where
 
                 co.yield_(Action::CancelBtc(signed_tx_cancel)).await;
 
-                match select(
+                bitcoin_client
-                    bitcoin_client.watch_for_raw_transaction(tx_cancel.txid()),
+                    .watch_for_raw_transaction(tx_cancel.txid())
-                    poll_until_bob_can_be_punished.clone(),
+                    .await;
+
+                let tx_cancel_height = bitcoin_client
+                    .transaction_block_height(tx_cancel.txid())
+                    .await;
+                let poll_until_bob_can_be_punished = poll_until_block_height_is_gte(
+                    bitcoin_client.as_ref(),
+                    tx_cancel_height + punish_timelock,
                 )
-                .await
+                .shared();
-                {
+                pin_mut!(poll_until_bob_can_be_punished);
-                    Either::Left(_) => {}
-                    Either::Right(_) => {
-                        return Err(RefundFailed::BtcPunishable {
-                            tx_cancel_was_published: false,
-                        })
-                    }
-                };
 
                 let tx_refund = bitcoin::TxRefund::new(&tx_cancel, &refund_address);
                 let tx_refund_published = match select(
@@ -282,11 +256,7 @@ where
                 .await
                 {
                     Either::Left((tx, _)) => tx,
-                    Either::Right(_) => {
+                    Either::Right(_) => return Err(RefundFailed::BtcPunishable),
-                        return Err(RefundFailed::BtcPunishable {
-                            tx_cancel_was_published: true,
-                        });
-                    }
                 };
 
                 let s_a = monero::PrivateKey {
@@ -321,32 +291,9 @@ where
             // transaction with his refund transaction. Alice would then need to carry on
             // with the refund on Monero. Doing so may be too verbose with the current,
             // linear approach. A different design may be required
-            if let Err(RefundFailed::BtcPunishable {
+            if let Err(RefundFailed::BtcPunishable) = refund_result {
-                tx_cancel_was_published,
-            }) = refund_result
-            {
                 let tx_cancel =
                     bitcoin::TxCancel::new(&tx_lock, refund_timelock, a.public(), B.clone());
-
-                if !tx_cancel_was_published {
-                    let tx_cancel_txid = tx_cancel.txid();
-                    let signed_tx_cancel = {
-                        let sig_a = a.sign(tx_cancel.digest());
-                        let sig_b = tx_cancel_sig_bob;
-
-                        tx_cancel
-                            .clone()
-                            .add_signatures(&tx_lock, (a.public(), sig_a), (B.clone(), sig_b))
-                            .expect("sig_{a,b} to be valid signatures for tx_cancel")
-                    };
-
-                    co.yield_(Action::CancelBtc(signed_tx_cancel)).await;
-
-                    let _ = bitcoin_client
-                        .watch_for_raw_transaction(tx_cancel_txid)
-                        .await;
-                }
-
                 let tx_punish =
                     bitcoin::TxPunish::new(&tx_cancel, &punish_address, punish_timelock);
                 let tx_punish_txid = tx_punish.txid();
@@ -684,7 +631,7 @@ impl State2 {
     }
 }
 
-#[derive(Clone, Debug, Deserialize, Serialize)]
+#[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
 pub struct State3 {
     pub a: bitcoin::SecretKey,
     pub B: bitcoin::PublicKey,

xmr-btc/src/bitcoin.rs

@@ -2,12 +2,7 @@ pub mod transactions;
 
 use anyhow::{anyhow, bail, Result};
 use async_trait::async_trait;
-use bitcoin::{
+use bitcoin::hashes::{hex::ToHex, Hash};
-    hashes::{hex::ToHex, Hash},
-    secp256k1,
-    util::psbt::PartiallySignedTransaction,
-    SigHash,
-};
 use ecdsa_fun::{adaptor::Adaptor, fun::Point, nonce::Deterministic, ECDSA};
 use miniscript::{Descriptor, Segwitv0};
 use rand::{CryptoRng, RngCore};
@@ -15,9 +10,9 @@ use serde::{Deserialize, Serialize};
 use sha2::Sha256;
 use std::str::FromStr;
 
-pub use crate::bitcoin::transactions::{TxCancel, TxLock, TxPunish, TxRedeem, TxRefund};
+pub use bitcoin::{util::psbt::PartiallySignedTransaction, *};
-pub use bitcoin::{Address, Amount, OutPoint, Transaction, Txid};
 pub use ecdsa_fun::{adaptor::EncryptedSignature, fun::Scalar, Signature};
+pub use transactions::{TxCancel, TxLock, TxPunish, TxRedeem, TxRefund};
 
 pub const TX_FEE: u64 = 10_000;
 

xmr-btc/src/bob.rs

@@ -495,7 +495,7 @@ impl State1 {
     }
 }
 
-#[derive(Debug, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, PartialEq)]
 pub struct State2 {
     pub A: bitcoin::PublicKey,
     pub b: bitcoin::SecretKey,
@@ -507,10 +507,10 @@ pub struct State2 {
     btc: bitcoin::Amount,
     pub xmr: monero::Amount,
     pub refund_timelock: u32,
-    punish_timelock: u32,
+    pub punish_timelock: u32,
     pub refund_address: bitcoin::Address,
     pub redeem_address: bitcoin::Address,
-    punish_address: bitcoin::Address,
+    pub punish_address: bitcoin::Address,
     pub tx_lock: bitcoin::TxLock,
     pub tx_cancel_sig_a: Signature,
     pub tx_refund_encsig: EncryptedSignature,

xmr-btc/src/monero.rs

@@ -1,12 +1,13 @@
 use crate::serde::monero_private_key;
 use anyhow::Result;
 use async_trait::async_trait;
-pub use curve25519_dalek::scalar::Scalar;
-pub use monero::{Address, PrivateKey, PublicKey};
 use rand::{CryptoRng, RngCore};
 use serde::{Deserialize, Serialize};
 use std::ops::{Add, Sub};
 
+pub use curve25519_dalek::scalar::Scalar;
+pub use monero::*;
+
 pub const MIN_CONFIRMATIONS: u32 = 10;
 
 pub fn random_private_key<R: RngCore + CryptoRng>(rng: &mut R) -> PrivateKey {

xmr-btc/tests/e2e.rs

@@ -13,7 +13,6 @@ mod tests {
     use rand::rngs::OsRng;
     use std::convert::TryInto;
     use testcontainers::clients::Cli;
-    use tracing_subscriber::util::SubscriberInitExt;
     use xmr_btc::{
         alice, bitcoin,
         bitcoin::{Amount, TX_FEE},
@@ -22,10 +21,6 @@ mod tests {
 
     #[tokio::test]
     async fn happy_path() {
-        let _guard = tracing_subscriber::fmt()
-            .with_env_filter("info")
-            .set_default();
-
         let cli = Cli::default();
         let (monero, _container) = Monero::new(&cli, Some("hp".to_string()), vec![
             "alice".to_string(),
@@ -101,10 +96,6 @@ mod tests {
 
     #[tokio::test]
     async fn both_refund() {
-        let _guard = tracing_subscriber::fmt()
-            .with_env_filter("info")
-            .set_default();
-
         let cli = Cli::default();
         let (monero, _container) = Monero::new(&cli, Some("br".to_string()), vec![
             "alice".to_string(),
@@ -182,10 +173,6 @@ mod tests {
 
     #[tokio::test]
     async fn alice_punishes() {
-        let _guard = tracing_subscriber::fmt()
-            .with_env_filter("info")
-            .set_default();
-
         let cli = Cli::default();
         let (monero, _containers) = Monero::new(&cli, Some("ap".to_string()), vec![
             "alice".to_string(),

xmr-btc/tests/harness/wallet/monero.rs

@@ -1,12 +1,11 @@
 use anyhow::Result;
 use async_trait::async_trait;
 use backoff::{backoff::Constant as ConstantBackoff, future::FutureOperation as _};
-use monero::{Address, Network, PrivateKey};
 use monero_harness::rpc::wallet;
 use std::{str::FromStr, time::Duration};
 use xmr_btc::monero::{
-    Amount, CreateWalletForOutput, InsufficientFunds, PrivateViewKey, PublicKey, PublicViewKey,
+    Address, Amount, CreateWalletForOutput, InsufficientFunds, Network, PrivateKey, PrivateViewKey,
-    Transfer, TransferProof, TxHash, WatchForTransfer,
+    PublicKey, PublicViewKey, Transfer, TransferProof, TxHash, WatchForTransfer,
 };
 
 pub struct Wallet(pub wallet::Client);

xmr-btc/tests/on_chain.rs

@@ -20,7 +20,7 @@ use tokio::sync::Mutex;
 use tracing::info;
 use xmr_btc::{
     alice::{self, ReceiveBitcoinRedeemEncsig},
-    bitcoin::{BroadcastSignedTransaction, EncryptedSignature, SignTxLock},
+    bitcoin::{self, BroadcastSignedTransaction, EncryptedSignature, SignTxLock},
     bob::{self, ReceiveTransferProof},
     monero::{CreateWalletForOutput, Transfer, TransferProof},
 };
@@ -309,8 +309,7 @@ async fn on_chain_happy_path() {
 
     assert_eq!(
         alice_final_btc_balance,
-        initial_balances.alice_btc + swap_amounts.btc
+        initial_balances.alice_btc + swap_amounts.btc - bitcoin::Amount::from_sat(bitcoin::TX_FEE)
-            - bitcoin::Amount::from_sat(xmr_btc::bitcoin::TX_FEE)
     );
     assert_eq!(
         bob_final_btc_balance,
@@ -411,7 +410,7 @@ async fn on_chain_both_refund_if_alice_never_redeems() {
         bob_final_btc_balance,
         // The 2 * TX_FEE corresponds to tx_refund and tx_cancel.
         initial_balances.bob_btc
-            - bitcoin::Amount::from_sat(2 * xmr_btc::bitcoin::TX_FEE)
+            - bitcoin::Amount::from_sat(2 * bitcoin::TX_FEE)
             - lock_tx_bitcoin_fee
     );
 
@@ -508,7 +507,7 @@ async fn on_chain_alice_punishes_if_bob_never_acts_after_fund() {
     assert_eq!(
         alice_final_btc_balance,
         initial_balances.alice_btc + swap_amounts.btc
-            - bitcoin::Amount::from_sat(2 * xmr_btc::bitcoin::TX_FEE)
+            - bitcoin::Amount::from_sat(2 * bitcoin::TX_FEE)
     );
     assert_eq!(
         bob_final_btc_balance,