Git-Mirrors/xmr-btc-swap
1
0
Fork 0
mirror of https://github.com/comit-network/xmr-btc-swap.git synced 2025-05-02 14:56:10 -04:00
Code Issues Projects Releases Packages Wiki Activity

Add Alice execution path

Browse source 
Consolidate and simplify swap execution. Generators are no longer
needed. Consolidate recovery and swap data structures. The
recursive calls can be replaced with a loop if returning prior to
completion is desired for testing purposes.

Fill out alice abort path

Move state machine executors into seperate files

Not compiling due to recursion/async issues

Fix async recursion compilation errors

Fix Bob swap execution

Remove check for ack message from Alice. Seems like a bad idea to
rely on an acknowledgement message instead of looking at the
blockchain.

Fix Bob abort

Fix warnings

Xmr lock complete

Add TxCancel submit to XmrLocked

Bob swap completed

Remove alice
This commit is contained in:
rishflab 2020-11-12 11:06:34 +11:00
parent e7682a42a4
commit dd07e2f882
10 changed files with 538 additions and 510 deletions
Download patch file Download diff file Expand all files Collapse all files

461
swap/src/alice.rs
View file

@ -1,461 +0,0 @@
//! Run an XMR/BTC swap in the role of Alice.
//! Alice holds XMR and wishes receive BTC.
use anyhow::Result;
use async_trait::async_trait;
use backoff::{backoff::Constant as ConstantBackoff, future::FutureOperation as _};
use genawaiter::GeneratorState;
use libp2p::{
core::{identity::Keypair, Multiaddr},
request_response::ResponseChannel,
NetworkBehaviour, PeerId,
};
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;
mod message1;
mod message2;
mod message3;
use self::{amounts::*, message0::*, message1::*, message2::*, message3::*};
use crate::{
bitcoin,
bitcoin::TX_LOCK_MINE_TIMEOUT,
monero,
network::{
peer_tracker::{self, PeerTracker},
request_response::AliceToBob,
transport::SwapTransport,
TokioExecutor,
},
state,
storage::Database,
SwapAmounts, PUNISH_TIMELOCK, REFUND_TIMELOCK,
};
use xmr_btc::{
alice::{self, action_generator, Action, ReceiveBitcoinRedeemEncsig, State0},
bitcoin::BroadcastSignedTransaction,
bob,
monero::{CreateWalletForOutput, Transfer},
};
pub async fn swap(
bitcoin_wallet: Arc<bitcoin::Wallet>,
monero_wallet: Arc<monero::Wallet>,
db: Database,
listen: Multiaddr,
transport: SwapTransport,
behaviour: Alice,
) -> Result<()> {
struct Network {
swarm: Arc<Mutex<Swarm>>,
channel: Option<ResponseChannel<AliceToBob>>,
}
impl Network {
pub async fn send_message2(&mut self, proof: monero::TransferProof) {
match self.channel.take() {
None => warn!("Channel not found, did you call this twice?"),
Some(channel) => {
let mut guard = self.swarm.lock().await;
guard.send_message2(channel, alice::Message2 {
tx_lock_proof: proof,
});
info!("Sent transfer proof");
}
}
}
}
// TODO: For retry, use `backoff::ExponentialBackoff` in production as opposed
// to `ConstantBackoff`.
#[async_trait]
impl ReceiveBitcoinRedeemEncsig for Network {
async fn receive_bitcoin_redeem_encsig(&mut self) -> bitcoin::EncryptedSignature {
#[derive(Debug)]
struct UnexpectedMessage;
let encsig = (|| async {
let mut guard = self.swarm.lock().await;
let encsig = match guard.next().await {
OutEvent::Message3(msg) => msg.tx_redeem_encsig,
other => {
warn!("Expected Bob's Bitcoin redeem encsig, got: {:?}", other);
return Err(backoff::Error::Transient(UnexpectedMessage));
}
};
Result::<_, backoff::Error<UnexpectedMessage>>::Ok(encsig)
})
.retry(ConstantBackoff::new(Duration::from_secs(1)))
.await
.expect("transient errors to be retried");
info!("Received Bitcoin redeem encsig");
encsig
}
}
let mut swarm = new_swarm(listen, transport, behaviour)?;
let message0: bob::Message0;
let mut state0: Option<alice::State0> = None;
let mut last_amounts: Option<SwapAmounts> = None;
// TODO: This loop is a neat idea for local development, as it allows us to keep
// Alice up and let Bob keep trying to connect, request amounts and/or send the
// first message of the handshake, but it comes at the cost of needing to handle
// mutable state, which has already been the source of a bug at one point. This
// is an obvious candidate for refactoring
loop {
match swarm.next().await {
OutEvent::ConnectionEstablished(bob) => {
info!("Connection established with: {}", bob);
}
OutEvent::Request(amounts::OutEvent::Btc { btc, channel }) => {
let amounts = calculate_amounts(btc);
last_amounts = Some(amounts);
swarm.send_amounts(channel, amounts);
let SwapAmounts { btc, xmr } = amounts;
let redeem_address = bitcoin_wallet.as_ref().new_address().await?;
let punish_address = redeem_address.clone();
// TODO: Pass this in using <R: RngCore + CryptoRng>
let rng = &mut OsRng;
let state = State0::new(
rng,
btc,
xmr,
REFUND_TIMELOCK,
PUNISH_TIMELOCK,
redeem_address,
punish_address,
);
info!("Commencing handshake");
swarm.set_state0(state.clone());
state0 = Some(state)
}
OutEvent::Message0(msg) => {
// We don't want Bob to be able to crash us by sending an out of
// order message. Keep looping if Bob has not requested amounts.
if last_amounts.is_some() {
// TODO: We should verify the amounts and notify Bob if they have changed.
message0 = msg;
break;
}
}
other => panic!("Unexpected event: {:?}", other),
};
}
let state1 = state0.expect("to be set").receive(message0)?;
let (state2, channel) = match swarm.next().await {
OutEvent::Message1 { msg, channel } => {
let state2 = state1.receive(msg);
(state2, channel)
}
other => panic!("Unexpected event: {:?}", other),
};
let msg = state2.next_message();
swarm.send_message1(channel, msg);
let (state3, channel) = match swarm.next().await {
OutEvent::Message2 { msg, channel } => {
let state3 = state2.receive(msg)?;
(state3, channel)
}
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 {
swarm: Arc::new(Mutex::new(swarm)),
channel: Some(channel),
}));
let mut action_generator = action_generator(
network.clone(),
bitcoin_wallet.clone(),
state3.clone(),
TX_LOCK_MINE_TIMEOUT,
);
loop {
let state = action_generator.async_resume().await;
tracing::info!("Resumed execution of generator, got: {:?}", state);
match state {
GeneratorState::Yielded(Action::LockXmr {
amount,
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(()) => {
db.insert_latest_state(swap_id, state::Alice::SwapComplete.into())
.await?;
return Ok(());
}
}
}
}
pub type Swarm = libp2p::Swarm<Alice>;
fn new_swarm(listen: Multiaddr, transport: SwapTransport, behaviour: Alice) -> Result<Swarm> {
use anyhow::Context as _;
let local_peer_id = behaviour.peer_id();
let mut swarm = libp2p::swarm::SwarmBuilder::new(transport, behaviour, local_peer_id.clone())
.executor(Box::new(TokioExecutor {
handle: tokio::runtime::Handle::current(),
}))
.build();
Swarm::listen_on(&mut swarm, listen.clone())
.with_context(|| format!("Address is not supported: {:#}", listen))?;
tracing::info!("Initialized swarm: {}", local_peer_id);
Ok(swarm)
}
#[allow(clippy::large_enum_variant)]
#[derive(Debug)]
pub enum OutEvent {
ConnectionEstablished(PeerId),
Request(amounts::OutEvent), // Not-uniform with Bob on purpose, ready for adding Xmr event.
Message0(bob::Message0),
Message1 {
msg: bob::Message1,
channel: ResponseChannel<AliceToBob>,
},
Message2 {
msg: bob::Message2,
channel: ResponseChannel<AliceToBob>,
},
Message3(bob::Message3),
}
impl From<peer_tracker::OutEvent> for OutEvent {
fn from(event: peer_tracker::OutEvent) -> Self {
match event {
peer_tracker::OutEvent::ConnectionEstablished(id) => {
OutEvent::ConnectionEstablished(id)
}
}
}
}
impl From<amounts::OutEvent> for OutEvent {
fn from(event: amounts::OutEvent) -> Self {
OutEvent::Request(event)
}
}
impl From<message0::OutEvent> for OutEvent {
fn from(event: message0::OutEvent) -> Self {
match event {
message0::OutEvent::Msg(msg) => OutEvent::Message0(msg),
}
}
}
impl From<message1::OutEvent> for OutEvent {
fn from(event: message1::OutEvent) -> Self {
match event {
message1::OutEvent::Msg { msg, channel } => OutEvent::Message1 { msg, channel },
}
}
}
impl From<message2::OutEvent> for OutEvent {
fn from(event: message2::OutEvent) -> Self {
match event {
message2::OutEvent::Msg { msg, channel } => OutEvent::Message2 { msg, channel },
}
}
}
impl From<message3::OutEvent> for OutEvent {
fn from(event: message3::OutEvent) -> Self {
match event {
message3::OutEvent::Msg(msg) => OutEvent::Message3(msg),
}
}
}
/// A `NetworkBehaviour` that represents an XMR/BTC swap node as Alice.
#[derive(NetworkBehaviour)]
#[behaviour(out_event = "OutEvent", event_process = false)]
#[allow(missing_debug_implementations)]
pub struct Alice {
pt: PeerTracker,
amounts: Amounts,
message0: Message0,
message1: Message1,
message2: Message2,
message3: Message3,
#[behaviour(ignore)]
identity: Keypair,
}
impl Alice {
pub fn identity(&self) -> Keypair {
self.identity.clone()
}
pub fn peer_id(&self) -> PeerId {
PeerId::from(self.identity.public())
}
/// Alice always sends her messages as a response to a request from Bob.
pub fn send_amounts(&mut self, channel: ResponseChannel<AliceToBob>, amounts: SwapAmounts) {
let msg = AliceToBob::Amounts(amounts);
self.amounts.send(channel, msg);
info!("Sent amounts response");
}
/// Message0 gets sent within the network layer using this state0.
pub fn set_state0(&mut self, state: State0) {
debug!("Set state 0");
let _ = self.message0.set_state(state);
}
/// Send Message1 to Bob in response to receiving his Message1.
pub fn send_message1(
&mut self,
channel: ResponseChannel<AliceToBob>,
msg: xmr_btc::alice::Message1,
) {
self.message1.send(channel, msg);
debug!("Sent Message1");
}
/// Send Message2 to Bob in response to receiving his Message2.
pub fn send_message2(
&mut self,
channel: ResponseChannel<AliceToBob>,
msg: xmr_btc::alice::Message2,
) {
self.message2.send(channel, msg);
debug!("Sent Message2");
}
}
impl Default for Alice {
fn default() -> Self {
let identity = Keypair::generate_ed25519();
Self {
pt: PeerTracker::default(),
amounts: Amounts::default(),
message0: Message0::default(),
message1: Message1::default(),
message2: Message2::default(),
message3: Message3::default(),
identity,
}
}
}
fn calculate_amounts(btc: ::bitcoin::Amount) -> SwapAmounts {
// TODO: Get this from an exchange.
// This value corresponds to 100 XMR per BTC
const PICONERO_PER_SAT: u64 = 1_000_000;
let picos = btc.as_sat() * PICONERO_PER_SAT;
let xmr = monero::Amount::from_piconero(picos);
SwapAmounts { btc, xmr }
}
#[cfg(test)]
mod tests {
use super::*;
const ONE_BTC: u64 = 100_000_000;
const HUNDRED_XMR: u64 = 100_000_000_000_000;
#[test]
fn one_bitcoin_equals_a_hundred_moneroj() {
let btc = ::bitcoin::Amount::from_sat(ONE_BTC);
let want = monero::Amount::from_piconero(HUNDRED_XMR);
let SwapAmounts { xmr: got, .. } = calculate_amounts(btc);
assert_eq!(got, want);
}
}