Move messages into `protocol` module

This allows us to remove all visibility modifiers from the message
fields because child modules (in this case {alice,bob}::state) can
always access private fields of structs.

It also moves the messages into a more natural place. Previously,
they were defined within the network layer even though they are
independent of the libp2p implementation.

swap/src/protocol.rs

@@ -1,7 +1,9 @@
+use crate::{bitcoin, monero};
 use conquer_once::Lazy;
 use ecdsa_fun::fun::marker::Mark;
+use serde::{Deserialize, Serialize};
 use sha2::Sha256;
-use sigma_fun::ext::dl_secp256k1_ed25519_eq::CrossCurveDLEQ;
+use sigma_fun::ext::dl_secp256k1_ed25519_eq::{CrossCurveDLEQ, CrossCurveDLEQProof};
 use sigma_fun::HashTranscript;
 
 pub mod alice;
@@ -18,6 +20,44 @@ pub static CROSS_CURVE_PROOF_SYSTEM: Lazy<
 
 #[derive(Debug, Copy, Clone)]
 pub struct StartingBalances {
-    pub xmr: crate::monero::Amount,
+    pub xmr: monero::Amount,
     pub btc: bitcoin::Amount,
 }
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct Message0 {
+    B: bitcoin::PublicKey,
+    S_b_monero: monero::PublicKey,
+    S_b_bitcoin: bitcoin::PublicKey,
+    dleq_proof_s_b: CrossCurveDLEQProof,
+    v_b: monero::PrivateViewKey,
+    refund_address: bitcoin::Address,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct Message1 {
+    A: bitcoin::PublicKey,
+    S_a_monero: monero::PublicKey,
+    S_a_bitcoin: bitcoin::PublicKey,
+    dleq_proof_s_a: CrossCurveDLEQProof,
+    v_a: monero::PrivateViewKey,
+    redeem_address: bitcoin::Address,
+    punish_address: bitcoin::Address,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct Message2 {
+    tx_lock: bitcoin::TxLock,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct Message3 {
+    tx_cancel_sig: bitcoin::Signature,
+    tx_refund_encsig: bitcoin::EncryptedSignature,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct Message4 {
+    tx_punish_sig: bitcoin::Signature,
+    tx_cancel_sig: bitcoin::Signature,
+}

swap/src/protocol/alice.rs

@@ -8,10 +8,8 @@ use uuid::Uuid;
 
 pub use self::behaviour::{Behaviour, OutEvent};
 pub use self::event_loop::{EventLoop, EventLoopHandle};
-pub use self::execution_setup::Message1;
 pub use self::state::*;
 pub use self::swap::{run, run_until};
-pub use execution_setup::Message3;
 
 mod behaviour;
 pub mod event_loop;

swap/src/protocol/alice/execution_setup.rs

@@ -1,30 +1,9 @@
-use crate::bitcoin::{EncryptedSignature, Signature};
 use crate::network::cbor_request_response::BUF_SIZE;
 use crate::protocol::alice::{State0, State3};
-use crate::protocol::bob::{Message0, Message2, Message4};
-use crate::{bitcoin, monero};
+use crate::protocol::{Message0, Message2, Message4};
 use anyhow::{Context, Error};
 use libp2p::PeerId;
 use libp2p_async_await::BehaviourOutEvent;
-use serde::{Deserialize, Serialize};
-use sigma_fun::ext::dl_secp256k1_ed25519_eq::CrossCurveDLEQProof;
-
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub struct Message1 {
-    pub(crate) A: bitcoin::PublicKey,
-    pub(crate) S_a_monero: monero::PublicKey,
-    pub(crate) S_a_bitcoin: bitcoin::PublicKey,
-    pub(crate) dleq_proof_s_a: CrossCurveDLEQProof,
-    pub(crate) v_a: monero::PrivateViewKey,
-    pub(crate) redeem_address: bitcoin::Address,
-    pub(crate) punish_address: bitcoin::Address,
-}
-
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub struct Message3 {
-    pub(crate) tx_cancel_sig: Signature,
-    pub(crate) tx_refund_encsig: EncryptedSignature,
-}
 
 #[derive(Debug)]
 pub enum OutEvent {

swap/src/protocol/alice/state.rs

@@ -5,9 +5,7 @@ use crate::env::Config;
 use crate::monero::wallet::{TransferRequest, WatchRequest};
 use crate::monero::TransferProof;
 use crate::monero_ext::ScalarExt;
-use crate::protocol::alice::{Message1, Message3};
-use crate::protocol::bob::{Message0, Message2, Message4};
-use crate::protocol::CROSS_CURVE_PROOF_SYSTEM;
+use crate::protocol::{Message0, Message1, Message2, Message3, Message4, CROSS_CURVE_PROOF_SYSTEM};
 use crate::{bitcoin, monero};
 use anyhow::{anyhow, bail, Context, Result};
 use monero_rpc::wallet::BlockHeight;

swap/src/protocol/bob.rs

@@ -4,7 +4,6 @@ use crate::network::{encrypted_signature, spot_price};
 use crate::protocol::bob;
 use crate::{bitcoin, monero};
 use anyhow::{anyhow, Error, Result};
-pub use execution_setup::{Message0, Message2, Message4};
 use libp2p::core::Multiaddr;
 use libp2p::request_response::{RequestResponseEvent, RequestResponseMessage, ResponseChannel};
 use libp2p::{NetworkBehaviour, PeerId};

swap/src/protocol/bob/execution_setup.rs

@@ -1,35 +1,11 @@
-use crate::bitcoin::Signature;
 use crate::network::cbor_request_response::BUF_SIZE;
-use crate::protocol::alice::{Message1, Message3};
 use crate::protocol::bob::{State0, State2};
+use crate::protocol::{Message1, Message3};
 use anyhow::{Context, Error, Result};
 use libp2p::PeerId;
 use libp2p_async_await::BehaviourOutEvent;
-use serde::{Deserialize, Serialize};
-use sigma_fun::ext::dl_secp256k1_ed25519_eq::CrossCurveDLEQProof;
 use std::sync::Arc;
 
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub struct Message0 {
-    pub(crate) B: crate::bitcoin::PublicKey,
-    pub(crate) S_b_monero: monero::PublicKey,
-    pub(crate) S_b_bitcoin: crate::bitcoin::PublicKey,
-    pub(crate) dleq_proof_s_b: CrossCurveDLEQProof,
-    pub(crate) v_b: crate::monero::PrivateViewKey,
-    pub(crate) refund_address: bitcoin::Address,
-}
-
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub struct Message2 {
-    pub(crate) tx_lock: crate::bitcoin::TxLock,
-}
-
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub struct Message4 {
-    pub(crate) tx_punish_sig: Signature,
-    pub(crate) tx_cancel_sig: Signature,
-}
-
 #[derive(Debug)]
 pub enum OutEvent {
     Done(Result<State2>),

swap/src/protocol/bob/state.rs

@@ -6,9 +6,7 @@ use crate::monero;
 use crate::monero::wallet::WatchRequest;
 use crate::monero::{monero_private_key, TransferProof};
 use crate::monero_ext::ScalarExt;
-use crate::protocol::alice::{Message1, Message3};
-use crate::protocol::bob::{Message0, Message2, Message4};
-use crate::protocol::CROSS_CURVE_PROOF_SYSTEM;
+use crate::protocol::{Message0, Message1, Message2, Message3, Message4, CROSS_CURVE_PROOF_SYSTEM};
 use anyhow::{anyhow, bail, Context, Result};
 use ecdsa_fun::adaptor::{Adaptor, HashTranscript};
 use ecdsa_fun::nonce::Deterministic;