Derive bitcoin private key from seed

swap/src/bin/nectar.rs

@@ -84,8 +84,12 @@ async fn main() -> Result<()> {
 
             let execution_params = execution_params::Testnet::get_execution_params();
 
-            let (bitcoin_wallet, monero_wallet) =
-                init_wallets(config.clone(), &wallet_data_dir).await?;
+            let (bitcoin_wallet, monero_wallet) = init_wallets(
+                config.clone(),
+                &wallet_data_dir,
+                seed.extended_private_key(BITCOIN_NETWORK)?.private_key,
+            )
+            .await?;
 
             let (mut event_loop, _) = EventLoop::new(
                 config.network.listen,
@@ -121,12 +125,14 @@ async fn main() -> Result<()> {
 async fn init_wallets(
     config: Config,
     bitcoin_wallet_data_dir: &Path,
+    private_key: ::bitcoin::PrivateKey,
 ) -> Result<(bitcoin::Wallet, monero::Wallet)> {
     let bitcoin_wallet = bitcoin::Wallet::new(
         config.bitcoin.electrum_rpc_url,
         config.bitcoin.electrum_http_url,
         BITCOIN_NETWORK,
         bitcoin_wallet_data_dir,
+        private_key,
     )
     .await?;
     let bitcoin_balance = bitcoin_wallet.balance().await?;

swap/src/bin/swap_cli.rs

@@ -90,8 +90,14 @@ async fn main() -> Result<()> {
             alice_addr,
             send_bitcoin,
         } => {
-            let (bitcoin_wallet, monero_wallet) =
-                init_wallets(config, bitcoin_network, &wallet_data_dir, monero_network).await?;
+            let (bitcoin_wallet, monero_wallet) = init_wallets(
+                config,
+                bitcoin_network,
+                &wallet_data_dir,
+                monero_network,
+                seed,
+            )
+            .await?;
 
             let swap_id = Uuid::new_v4();
 
@@ -132,8 +138,14 @@ async fn main() -> Result<()> {
             alice_peer_id,
             alice_addr,
         }) => {
-            let (bitcoin_wallet, monero_wallet) =
-                init_wallets(config, bitcoin_network, &wallet_data_dir, monero_network).await?;
+            let (bitcoin_wallet, monero_wallet) = init_wallets(
+                config,
+                bitcoin_network,
+                &wallet_data_dir,
+                monero_network,
+                seed,
+            )
+            .await?;
 
             let bob_factory = Builder::new(
                 seed,
@@ -157,8 +169,14 @@ async fn main() -> Result<()> {
             force,
         }) => {
             // TODO: Optimization: Only init the Bitcoin wallet, Monero wallet unnecessary
-            let (bitcoin_wallet, monero_wallet) =
-                init_wallets(config, bitcoin_network, &wallet_data_dir, monero_network).await?;
+            let (bitcoin_wallet, monero_wallet) = init_wallets(
+                config,
+                bitcoin_network,
+                &wallet_data_dir,
+                monero_network,
+                seed,
+            )
+            .await?;
 
             let bob_factory = Builder::new(
                 seed,
@@ -201,8 +219,14 @@ async fn main() -> Result<()> {
             alice_addr,
             force,
         }) => {
-            let (bitcoin_wallet, monero_wallet) =
-                init_wallets(config, bitcoin_network, &wallet_data_dir, monero_network).await?;
+            let (bitcoin_wallet, monero_wallet) = init_wallets(
+                config,
+                bitcoin_network,
+                &wallet_data_dir,
+                monero_network,
+                seed,
+            )
+            .await?;
 
             // TODO: Optimize to only use the Bitcoin wallet, Monero wallet is unnecessary
             let bob_factory = Builder::new(
@@ -238,12 +262,14 @@ async fn init_wallets(
     bitcoin_network: bitcoin::Network,
     bitcoin_wallet_data_dir: &Path,
     monero_network: monero::Network,
+    seed: Seed,
 ) -> Result<(bitcoin::Wallet, monero::Wallet)> {
     let bitcoin_wallet = bitcoin::Wallet::new(
         config.bitcoin.electrum_rpc_url,
         config.bitcoin.electrum_http_url,
         bitcoin_network,
         bitcoin_wallet_data_dir,
+        seed.extended_private_key(bitcoin_network)?.private_key,
     )
     .await?;
 

swap/src/bitcoin/wallet.rs

@@ -13,7 +13,7 @@ use backoff::{backoff::Constant as ConstantBackoff, tokio::retry};
 use bdk::{
     blockchain::{noop_progress, Blockchain, ElectrumBlockchain},
     electrum_client::{self, Client, ElectrumApi},
-    keys::GeneratableDefaultOptions,
+    miniscript::bitcoin::PrivateKey,
     FeeRate,
 };
 use reqwest::{Method, Url};
@@ -43,7 +43,8 @@ impl Wallet {
         electrum_rpc_url: Url,
         electrum_http_url: Url,
         network: bitcoin::Network,
-        waller_dir: &Path,
+        wallet_dir: &Path,
+        private_key: PrivateKey,
     ) -> Result<Self> {
         // Workaround for https://github.com/bitcoindevkit/rust-electrum-client/issues/47.
         let config = electrum_client::ConfigBuilder::default().retry(2).build();
@@ -51,11 +52,10 @@ impl Wallet {
         let client = Client::from_config(electrum_rpc_url.as_str(), config)
             .map_err(|e| anyhow!("Failed to init electrum rpc client: {:?}", e))?;
 
-        let db = bdk::sled::open(waller_dir)?.open_tree(SLED_TREE_NAME)?;
+        let db = bdk::sled::open(wallet_dir)?.open_tree(SLED_TREE_NAME)?;
 
-        let p_key = ::bitcoin::PrivateKey::generate_default()?;
         let bdk_wallet = bdk::Wallet::new(
-            bdk::template::P2WPKH(p_key),
+            bdk::template::P2WPKH(private_key),
             None,
             network,
             db,

swap/src/seed.rs

@@ -1,5 +1,7 @@
 use crate::fs::ensure_directory_exists;
 use ::bitcoin::secp256k1::{self, constants::SECRET_KEY_SIZE, SecretKey};
+use anyhow::Result;
+use bdk::bitcoin::util::bip32::ExtendedPrivKey;
 use pem::{encode, Pem};
 use rand::prelude::*;
 use std::{
@@ -26,6 +28,11 @@ impl Seed {
         Ok(Seed(bytes))
     }
 
+    pub fn extended_private_key(&self, network: bitcoin::Network) -> Result<ExtendedPrivKey> {
+        let private_key = ExtendedPrivKey::new_master(network, &self.bytes())?;
+        Ok(private_key)
+    }
+
     pub fn bytes(&self) -> [u8; SEED_LENGTH] {
         self.0
     }

swap/tests/testutils/mod.rs

@@ -346,6 +346,9 @@ where
         .get_host_port(testutils::electrs::HTTP_PORT)
         .expect("Could not map electrs http port");
 
+    let alice_seed = Seed::random().unwrap();
+    let bob_seed = Seed::random().unwrap();
+
     let (alice_bitcoin_wallet, alice_monero_wallet) = init_test_wallets(
         "alice",
         containers.bitcoind_url.clone(),
@@ -354,6 +357,7 @@ where
         tempdir().unwrap().path(),
         electrs_rpc_port,
         electrs_http_port,
+        alice_seed,
     )
     .await;
 
@@ -375,6 +379,7 @@ where
         tempdir().unwrap().path(),
         electrs_rpc_port,
         electrs_http_port,
+        bob_seed,
     )
     .await;
 
@@ -570,6 +575,7 @@ async fn init_monero_container(
     (monero, monerods)
 }
 
+#[allow(clippy::too_many_arguments)]
 async fn init_test_wallets(
     name: &str,
     bitcoind_url: Url,
@@ -578,6 +584,7 @@ async fn init_test_wallets(
     datadir: &Path,
     electrum_rpc_port: u16,
     electrum_http_port: u16,
+    seed: Seed,
 ) -> (Arc<bitcoin::Wallet>, Arc<monero::Wallet>) {
     monero
         .init(vec![(name, starting_balances.xmr.as_piconero())])
@@ -603,6 +610,9 @@ async fn init_test_wallets(
         electrum_http_url,
         bitcoin::Network::Regtest,
         datadir,
+        seed.extended_private_key(bitcoin::Network::Regtest)
+            .expect("Could not create extended private key from seed")
+            .private_key,
     )
     .await
     .expect("could not init btc wallet");