feat(emergency kit): Add resend settle finalize message

crates/ln-dlc-node/src/bitcoin_conversion.rs

@@ -179,6 +179,11 @@ pub fn to_secp_sk_30(sk: bitcoin_old::secp256k1::SecretKey) -> bitcoin::secp256k
     bitcoin::secp256k1::SecretKey::from_slice(&sk).expect("valid conversion")
 }
 
+pub fn to_secp_sk_29(sk: bitcoin::secp256k1::SecretKey) -> bitcoin_old::secp256k1::SecretKey {
+    let sk = sk.secret_bytes();
+    bitcoin_old::secp256k1::SecretKey::from_slice(&sk).expect("valid conversion")
+}
+
 pub fn to_ecdsa_signature_30(signature: bitcoin_old::secp256k1::ecdsa::Signature) -> Signature {
     let sig = signature.serialize_compact();
     Signature::from_compact(&sig).expect("valid conversion")

mobile/lib/common/settings/emergency_kit_screen.dart

@@ -163,6 +163,24 @@ class _EmergencyKitScreenState extends State<EmergencyKitScreen> {
                           goRouter.pop();
                         }),
                     const SizedBox(height: 30),
+                    EmergencyKitButton(
+                        icon: const Icon(FontAwesomeIcons.broom),
+                        title: "Resend SettleFinalize Message",
+                        onPressed: () async {
+                          final messenger = ScaffoldMessenger.of(context);
+                          final goRouter = GoRouter.of(context);
+
+                          try {
+                            await rust.api.resendSettleFinalizeMessage();
+                            showSnackBar(messenger, "Successfully resend SettleFinalize message");
+                          } catch (e) {
+                            showSnackBar(
+                                messenger, "Failed to resend SettleFinalize message. Error: $e");
+                          }
+
+                          goRouter.pop();
+                        }),
+                    const SizedBox(height: 30),
                     Visibility(
                         visible: config.network == "regtest",
                         child: EmergencyKitButton(

mobile/native/src/api.rs

@@ -395,6 +395,10 @@ pub fn delete_position() -> Result<()> {
     emergency_kit::delete_position()
 }
 
+pub fn resend_settle_finalize_message() -> Result<()> {
+    emergency_kit::resend_settle_finalize_message()
+}
+
 pub fn subscribe(stream: StreamSink<event::api::Event>) {
     tracing::debug!("Subscribing flutter to event hub");
     event::subscribe(FlutterSubscriber::new(stream))

mobile/native/src/emergency_kit.rs

@@ -1,11 +1,22 @@
+use crate::config;
 use crate::db;
 use crate::db::connection;
 use crate::event;
 use crate::event::EventInternal;
 use crate::ln_dlc;
+use crate::state::get_node;
+use anyhow::ensure;
 use anyhow::Result;
+use bitcoin::secp256k1::SecretKey;
 use dlc_manager::DlcChannelId;
+use dlc_manager::Signer;
+use dlc_messages::channel::SettleFinalize;
+use dlc_messages::ChannelMessage;
+use dlc_messages::Message;
 use hex::FromHex;
+use lightning::ln::chan_utils::build_commitment_secret;
+use ln_dlc_node::bitcoin_conversion::to_secp_sk_29;
+use ln_dlc_node::node::event::NodeEvent;
 use trade::ContractSymbol;
 
 pub fn set_filling_orders_to_failed() -> Result<()> {
@@ -32,3 +43,46 @@ pub fn delete_position() -> Result<()> {
     ));
     Ok(())
 }
+
+pub fn resend_settle_finalize_message() -> Result<()> {
+    tracing::warn!("Executing emergency kit! Resending settle finalize message");
+    let coordinator_pubkey = config::get_coordinator_info().pubkey;
+
+    let node = get_node();
+    let signed_channel = node
+        .inner
+        .get_signed_channel_by_trader_id(coordinator_pubkey)?;
+
+    ensure!(
+        matches!(
+            signed_channel.state,
+            dlc_manager::channel::signed_channel::SignedChannelState::Settled { .. }
+        ),
+        "Signed channel state must be settled to resend settle finalize message!"
+    );
+
+    let per_update_seed_pk = signed_channel.own_per_update_seed;
+    let per_update_seed = node
+        .inner
+        .dlc_wallet
+        .get_secret_key_for_pubkey(&per_update_seed_pk)?;
+    let prev_per_update_secret = SecretKey::from_slice(&build_commitment_secret(
+        per_update_seed.as_ref(),
+        signed_channel.update_idx + 1,
+    ))?;
+
+    let msg = Message::Channel(ChannelMessage::SettleFinalize(SettleFinalize {
+        channel_id: signed_channel.channel_id,
+        prev_per_update_secret: to_secp_sk_29(prev_per_update_secret),
+        reference_id: signed_channel.reference_id,
+    }));
+
+    node.inner
+        .event_handler
+        .publish(NodeEvent::SendDlcMessage {
+            peer: coordinator_pubkey,
+            msg: msg.clone(),
+        })?;
+
+    Ok(())
+}