Save Bob state during swap

swap/src/bob/swap.rs

@@ -1,5 +1,7 @@
 use crate::{
     bob::{event_loop::EventLoopHandle, execution::negotiate},
+    state,
+    state::Bob,
     storage::Database,
     SwapAmounts,
 };
@@ -17,6 +19,7 @@ use xmr_btc::{
 
 // The same data structure is used for swap execution and recovery.
 // This allows for a seamless transition from a failed swap to recovery.
+#[derive(Debug, Clone)]
 pub enum BobState {
     Started {
         state0: bob::State0,
@@ -53,6 +56,32 @@ impl fmt::Display for BobState {
     }
 }
 
+impl From<BobState> for state::Bob {
+    fn from(bob_state: BobState) -> Self {
+        match bob_state {
+            BobState::Started {
+                state0,
+                amounts,
+                addr,
+            } => Bob::Started {
+                state0,
+                amounts,
+                addr,
+            },
+            BobState::Negotiated(state2, peer_id) => Bob::Negotiated { state2, peer_id },
+            BobState::BtcLocked(state3, peer_id) => Bob::BtcLocked { state3, peer_id },
+            BobState::XmrLocked(state4, peer_id) => Bob::XmrLocked { state4, peer_id },
+            BobState::EncSigSent(state4, peer_id) => Bob::EncSigSent { state4, peer_id },
+            BobState::BtcRedeemed(state5) => Bob::BtcRedeemed(state5),
+            BobState::Cancelled(state4) => Bob::BtcCancelled(state4),
+            BobState::BtcRefunded(_)
+            | BobState::XmrRedeemed
+            | BobState::Punished
+            | BobState::SafelyAborted => Bob::SwapComplete,
+        }
+    }
+}
+
 pub async fn swap<R>(
     state: BobState,
     event_loop_handle: EventLoopHandle,
@@ -131,8 +160,13 @@ where
                     bitcoin_wallet.clone(),
                 )
                 .await?;
+
+                let state = BobState::Negotiated(state2, alice_peer_id);
+                let db_state = state.clone().into();
+                db.insert_latest_state(swap_id, state::Swap::Bob(db_state))
+                    .await?;
                 run_until(
-                    BobState::Negotiated(state2, alice_peer_id),
+                    state,
                     is_target_state,
                     event_loop_handle,
                     db,
@@ -146,9 +180,13 @@ where
             BobState::Negotiated(state2, alice_peer_id) => {
                 // Alice and Bob have exchanged info
                 let state3 = state2.lock_btc(bitcoin_wallet.as_ref()).await?;
-                // db.insert_latest_state(state);
+
+                let state = BobState::BtcLocked(state3, alice_peer_id);
+                let db_state = state.clone().into();
+                db.insert_latest_state(swap_id, state::Swap::Bob(db_state))
+                    .await?;
                 run_until(
-                    BobState::BtcLocked(state3, alice_peer_id),
+                    state,
                     is_target_state,
                     event_loop_handle,
                     db,
@@ -168,8 +206,12 @@ where
                     .watch_for_lock_xmr(monero_wallet.as_ref(), msg2)
                     .await?;
 
+                let state = BobState::XmrLocked(state4, alice_peer_id);
+                let db_state = state.clone().into();
+                db.insert_latest_state(swap_id, state::Swap::Bob(db_state))
+                    .await?;
                 run_until(
-                    BobState::XmrLocked(state4, alice_peer_id),
+                    state,
                     is_target_state,
                     event_loop_handle,
                     db,
@@ -192,8 +234,12 @@ where
                     .send_message3(alice_peer_id.clone(), tx_redeem_encsig)
                     .await?;
 
+                let state = BobState::EncSigSent(state, alice_peer_id);
+                let db_state = state.clone().into();
+                db.insert_latest_state(swap_id, state::Swap::Bob(db_state))
+                    .await?;
                 run_until(
-                    BobState::EncSigSent(state, alice_peer_id),
+                    state,
                     is_target_state,
                     event_loop_handle,
                     db,
@@ -209,10 +255,14 @@ where
                 let redeem_watcher = state.watch_for_redeem_btc(bitcoin_wallet.as_ref());
                 let t1_timeout = state.wait_for_t1(bitcoin_wallet.as_ref());
 
+                // TODO(Franck): Check if db save and run_until can be factorized
                 tokio::select! {
                     val = redeem_watcher => {
+                        let state = BobState::BtcRedeemed(val?);
+                        let db_state = state.clone().into();
+                        db.insert_latest_state(swap_id, state::Swap::Bob(db_state)).await?;
                         run_until(
-                            BobState::BtcRedeemed(val?),
+                            state,
                                  is_target_state,
                             event_loop_handle,
                             db,
@@ -230,15 +280,18 @@ where
                             state.submit_tx_cancel(bitcoin_wallet.as_ref()).await?;
                         }
 
+                        let state = BobState::Cancelled(state);
+                        let db_state = state.clone().into();
+                        db.insert_latest_state(swap_id, state::Swap::Bob(db_state)).await?;
                         run_until(
-                            BobState::Cancelled(state),
-                                 is_target_state,
+                            state,
+                            is_target_state,
                             event_loop_handle,
                             db,
                             bitcoin_wallet,
                             monero_wallet,
                             rng,
-                     swap_id
+                            swap_id
                         )
                         .await
 
@@ -248,8 +301,13 @@ where
             BobState::BtcRedeemed(state) => {
                 // Bob redeems XMR using revealed s_a
                 state.claim_xmr(monero_wallet.as_ref()).await?;
+
+                let state = BobState::XmrRedeemed;
+                let db_state = state.clone().into();
+                db.insert_latest_state(swap_id, state::Swap::Bob(db_state))
+                    .await?;
                 run_until(
-                    BobState::XmrRedeemed,
+                    state,
                     is_target_state,
                     event_loop_handle,
                     db,
@@ -261,37 +319,31 @@ where
                 .await
             }
             BobState::Cancelled(state) => {
+                // TODO
                 // Bob has cancelled the swap
-                match state.current_epoch(bitcoin_wallet.as_ref()).await? {
+                let state = match state.current_epoch(bitcoin_wallet.as_ref()).await? {
                     Epoch::T0 => panic!("Cancelled before t1??? Something is really wrong"),
                     Epoch::T1 => {
                         state.refund_btc(bitcoin_wallet.as_ref()).await?;
-                        run_until(
-                            BobState::BtcRefunded(state),
-                            is_target_state,
-                            event_loop_handle,
-                            db,
-                            bitcoin_wallet,
-                            monero_wallet,
-                            rng,
-                            swap_id,
-                        )
-                        .await
+                        BobState::BtcRefunded(state)
                     }
-                    Epoch::T2 => {
-                        run_until(
-                            BobState::Punished,
-                            is_target_state,
-                            event_loop_handle,
-                            db,
-                            bitcoin_wallet,
-                            monero_wallet,
-                            rng,
-                            swap_id,
-                        )
-                        .await
-                    }
-                }
+                    Epoch::T2 => BobState::Punished,
+                };
+
+                let db_state = state.clone().into();
+                db.insert_latest_state(swap_id, state::Swap::Bob(db_state))
+                    .await?;
+                run_until(
+                    state,
+                    is_target_state,
+                    event_loop_handle,
+                    db,
+                    bitcoin_wallet,
+                    monero_wallet,
+                    rng,
+                    swap_id,
+                )
+                .await
             }
             BobState::BtcRefunded(state4) => Ok(BobState::BtcRefunded(state4)),
             BobState::Punished => Ok(BobState::Punished),

swap/src/lib.rs

@@ -1,6 +1,6 @@
 #![allow(non_snake_case)]
 
-use serde::{Deserialize, Serialize};
+use ::serde::{Deserialize, Serialize};
 use std::fmt::{self, Display};
 
 pub mod alice;
@@ -10,6 +10,7 @@ pub mod cli;
 pub mod monero;
 pub mod network;
 pub mod recover;
+pub mod serde;
 pub mod state;
 pub mod storage;
 pub mod tor;
@@ -31,7 +32,7 @@ pub enum Rsp {
 }
 
 /// XMR/BTC swap amounts.
-#[derive(Copy, Clone, Debug, Serialize, Deserialize)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq)]
 // TODO(Franck): review necessity of this struct
 pub struct SwapAmounts {
     /// Amount of BTC to swap.

swap/src/recover.rs

@@ -24,9 +24,12 @@ use futures::{
 };
 use sha2::Sha256;
 use tracing::info;
-use xmr_btc::bitcoin::{
-    poll_until_block_height_is_gte, BroadcastSignedTransaction, TransactionBlockHeight,
-    WatchForRawTransaction,
+use xmr_btc::{
+    bitcoin::{
+        poll_until_block_height_is_gte, BroadcastSignedTransaction, TransactionBlockHeight,
+        WatchForRawTransaction,
+    },
+    bob::{State3, State4},
 };
 
 pub async fn recover(
@@ -366,18 +369,53 @@ pub async fn bob_recover(
     state: Bob,
 ) -> Result<()> {
     match state {
-        Bob::Handshaken(_) | Bob::SwapComplete => {
+        Bob::Negotiated { .. } | Bob::SwapComplete => {
             info!("Nothing to do");
         }
-        Bob::BtcLocked(state) | Bob::XmrLocked(state) | Bob::BtcRefundable(state) => {
+        Bob::BtcLocked {
+            state3:
+                State3 {
+                    A,
+                    b,
+                    s_b,
+                    refund_timelock,
+                    refund_address,
+                    tx_lock,
+                    tx_cancel_sig_a,
+                    tx_refund_encsig,
+                    ..
+                },
+            ..
+        }
+        | Bob::XmrLocked {
+            state4:
+                State4 {
+                    A,
+                    b,
+                    s_b,
+                    refund_timelock,
+                    refund_address,
+                    tx_lock,
+                    tx_cancel_sig_a,
+                    tx_refund_encsig,
+                    ..
+                },
+            ..
+        }
+        | Bob::BtcCancelled(State4 {
+            A,
+            b,
+            s_b,
+            refund_timelock,
+            refund_address,
+            tx_lock,
+            tx_cancel_sig_a,
+            tx_refund_encsig,
+            ..
+        }) => {
             info!("Bitcoin may still be locked up, attempting to refund");
 
-            let tx_cancel = bitcoin::TxCancel::new(
-                &state.tx_lock,
-                state.refund_timelock,
-                state.A,
-                state.b.public(),
-            );
+            let tx_cancel = bitcoin::TxCancel::new(&tx_lock, refund_timelock, A, b.public());
 
             info!("Checking if the Bitcoin cancel transaction has been published");
             if bitcoin_wallet
@@ -389,20 +427,17 @@ pub async fn bob_recover(
                 info!("Bitcoin cancel transaction not yet published");
 
                 let tx_lock_height = bitcoin_wallet
-                    .transaction_block_height(state.tx_lock.txid())
+                    .transaction_block_height(tx_lock.txid())
+                    .await;
+                poll_until_block_height_is_gte(&bitcoin_wallet, tx_lock_height + refund_timelock)
                     .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 sig_a = tx_cancel_sig_a.clone();
+                let sig_b = b.sign(tx_cancel.digest());
 
                 let tx_cancel = tx_cancel
                     .clone()
-                    .add_signatures(&state.tx_lock, (state.A, sig_a), (state.b.public(), sig_b))
+                    .add_signatures(&tx_lock, (A, sig_a), (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
@@ -413,15 +448,15 @@ pub async fn bob_recover(
 
             info!("Confirmed that Bitcoin cancel transaction is on the blockchain");
 
-            let tx_refund = bitcoin::TxRefund::new(&tx_cancel, &state.refund_address);
+            let tx_refund = bitcoin::TxRefund::new(&tx_cancel, &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());
+                let sig_a =
+                    adaptor.decrypt_signature(&s_b.into_secp256k1(), tx_refund_encsig.clone());
+                let sig_b = b.sign(tx_refund.digest());
 
                 tx_refund
-                    .add_signatures(&tx_cancel, (state.A, sig_a), (state.b.public(), sig_b))
+                    .add_signatures(&tx_cancel, (A, sig_a), (b.public(), sig_b))
                     .expect("sig_{a,b} to be valid signatures for tx_refund")
             };
 
@@ -459,6 +494,8 @@ pub async fn bob_recover(
                 .await?;
             info!("Successfully redeemed monero")
         }
+        Bob::Started { .. } => todo!(),
+        Bob::EncSigSent { .. } => todo!(),
     };
 
     Ok(())

swap/src/serde.rs

@@ -0,0 +1,47 @@
+pub mod peer_id {
+    use libp2p::PeerId;
+    use serde::{de::Error, Deserialize, Deserializer, Serializer};
+
+    pub fn serialize<S>(peer_id: &PeerId, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let string = peer_id.to_string();
+        serializer.serialize_str(&string)
+    }
+
+    #[allow(dead_code)]
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<PeerId, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let string = String::deserialize(deserializer)?;
+        let peer_id = string.parse().map_err(D::Error::custom)?;
+
+        Ok(peer_id)
+    }
+
+    #[cfg(test)]
+    mod tests {
+        use super::*;
+        use serde::Serialize;
+        use spectral::prelude::*;
+
+        #[derive(Serialize)]
+        struct SerializablePeerId(#[serde(with = "super")] PeerId);
+
+        #[test]
+        fn maker_id_serializes_as_expected() {
+            let peer_id = SerializablePeerId(
+                "QmfUfpC2frwFvcDzpspnfZitHt5wct6n4kpG5jzgRdsxkY"
+                    .parse()
+                    .unwrap(),
+            );
+
+            let got = serde_json::to_string(&peer_id).expect("failed to serialize peer id");
+
+            assert_that(&got)
+                .is_equal_to(r#""QmfUfpC2frwFvcDzpspnfZitHt5wct6n4kpG5jzgRdsxkY""#.to_string());
+        }
+    }
+}

swap/src/state.rs

@@ -1,3 +1,5 @@
+use crate::SwapAmounts;
+use libp2p::{core::Multiaddr, PeerId};
 use serde::{Deserialize, Serialize};
 use std::fmt::Display;
 use xmr_btc::{alice, bitcoin::EncryptedSignature, bob, monero, serde::monero_private_key};
@@ -37,11 +39,33 @@ pub enum Alice {
 
 #[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
 pub enum Bob {
-    Handshaken(bob::State2),
-    BtcLocked(bob::State2),
-    XmrLocked(bob::State2),
-    BtcRedeemed(bob::State2),
-    BtcRefundable(bob::State2),
+    Started {
+        state0: bob::State0,
+        amounts: SwapAmounts,
+        addr: Multiaddr,
+    },
+    Negotiated {
+        state2: bob::State2,
+        #[serde(with = "crate::serde::peer_id")]
+        peer_id: PeerId,
+    },
+    BtcLocked {
+        state3: bob::State3,
+        #[serde(with = "crate::serde::peer_id")]
+        peer_id: PeerId,
+    },
+    XmrLocked {
+        state4: bob::State4,
+        #[serde(with = "crate::serde::peer_id")]
+        peer_id: PeerId,
+    },
+    EncSigSent {
+        state4: bob::State4,
+        #[serde(with = "crate::serde::peer_id")]
+        peer_id: PeerId,
+    },
+    BtcRedeemed(bob::State5),
+    BtcCancelled(bob::State4),
     SwapComplete,
 }
 
@@ -85,12 +109,14 @@ impl Display for Alice {
 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(_) => {
+            Bob::Negotiated { .. } => f.write_str("Handshake complete"),
+            Bob::BtcLocked { .. } | Bob::XmrLocked { .. } | Bob::BtcCancelled(_) => {
                 f.write_str("Bitcoin refundable")
             }
             Bob::BtcRedeemed(_) => f.write_str("Monero redeemable"),
             Bob::SwapComplete => f.write_str("Swap complete"),
+            Bob::Started { .. } => f.write_str("Swap started"),
+            Bob::EncSigSent { .. } => f.write_str("Encrypted signature sent"),
         }
     }
 }

xmr-btc/src/bob.rs

@@ -346,7 +346,7 @@ impl_from_child_enum!(State3, State);
 impl_from_child_enum!(State4, State);
 impl_from_child_enum!(State5, State);
 
-#[derive(Debug, Deserialize, Serialize)]
+#[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
 pub struct State0 {
     b: bitcoin::SecretKey,
     s_b: cross_curve_dleq::Scalar,
@@ -560,25 +560,25 @@ impl State2 {
     }
 }
 
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
 pub struct State3 {
-    A: bitcoin::PublicKey,
-    b: bitcoin::SecretKey,
-    s_b: cross_curve_dleq::Scalar,
+    pub A: bitcoin::PublicKey,
+    pub b: bitcoin::SecretKey,
+    pub s_b: cross_curve_dleq::Scalar,
     S_a_monero: monero::PublicKey,
     S_a_bitcoin: bitcoin::PublicKey,
     v: monero::PrivateViewKey,
     #[serde(with = "::bitcoin::util::amount::serde::as_sat")]
     btc: bitcoin::Amount,
     xmr: monero::Amount,
-    refund_timelock: u32,
+    pub refund_timelock: u32,
     punish_timelock: u32,
-    refund_address: bitcoin::Address,
+    pub refund_address: bitcoin::Address,
     redeem_address: bitcoin::Address,
     punish_address: bitcoin::Address,
-    tx_lock: bitcoin::TxLock,
-    tx_cancel_sig_a: Signature,
-    tx_refund_encsig: EncryptedSignature,
+    pub tx_lock: bitcoin::TxLock,
+    pub tx_cancel_sig_a: Signature,
+    pub tx_refund_encsig: EncryptedSignature,
 }
 
 impl State3 {
@@ -626,11 +626,11 @@ impl State3 {
     }
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, PartialEq)]
 pub struct State4 {
     pub A: bitcoin::PublicKey,
     pub b: bitcoin::SecretKey,
-    s_b: cross_curve_dleq::Scalar,
+    pub s_b: cross_curve_dleq::Scalar,
     S_a_monero: monero::PublicKey,
     pub S_a_bitcoin: bitcoin::PublicKey,
     v: monero::PrivateViewKey,
@@ -639,12 +639,12 @@ pub struct State4 {
     xmr: monero::Amount,
     pub refund_timelock: u32,
     punish_timelock: u32,
-    refund_address: bitcoin::Address,
+    pub refund_address: bitcoin::Address,
     pub redeem_address: bitcoin::Address,
     punish_address: bitcoin::Address,
     pub tx_lock: bitcoin::TxLock,
-    tx_cancel_sig_a: Signature,
-    tx_refund_encsig: EncryptedSignature,
+    pub tx_cancel_sig_a: Signature,
+    pub tx_refund_encsig: EncryptedSignature,
 }
 
 impl State4 {
@@ -823,25 +823,25 @@ impl State4 {
     }
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, PartialEq)]
 pub struct State5 {
     A: bitcoin::PublicKey,
-    b: bitcoin::SecretKey,
+    pub b: bitcoin::SecretKey,
     #[serde(with = "monero_private_key")]
     s_a: monero::PrivateKey,
-    s_b: cross_curve_dleq::Scalar,
+    pub s_b: cross_curve_dleq::Scalar,
     S_a_monero: monero::PublicKey,
-    S_a_bitcoin: bitcoin::PublicKey,
-    v: monero::PrivateViewKey,
+    pub S_a_bitcoin: bitcoin::PublicKey,
+    pub v: monero::PrivateViewKey,
     #[serde(with = "::bitcoin::util::amount::serde::as_sat")]
     btc: bitcoin::Amount,
     xmr: monero::Amount,
     refund_timelock: u32,
     punish_timelock: u32,
     refund_address: bitcoin::Address,
-    redeem_address: bitcoin::Address,
+    pub redeem_address: bitcoin::Address,
     punish_address: bitcoin::Address,
-    tx_lock: bitcoin::TxLock,
+    pub tx_lock: bitcoin::TxLock,
     tx_refund_encsig: EncryptedSignature,
     tx_cancel_sig: Signature,
 }