From c05ba79e4b33e0c44bea97492ee26e5299d45099 Mon Sep 17 00:00:00 2001
From: thedevbirb <lorenzo.feroleto.dev@gmail.com>
Date: Thu, 10 Oct 2024 11:41:44 +0200
Subject: [PATCH] feat(sidecar): add keystore signer to driver

---
 bolt-sidecar/bin/sidecar.rs         | 11 ++++++++++-
 bolt-sidecar/src/driver.rs          | 25 ++++++++++++++++++++++---
 bolt-sidecar/src/signer/keystore.rs |  4 +++-
 3 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/bolt-sidecar/bin/sidecar.rs b/bolt-sidecar/bin/sidecar.rs
index ab63b2ee5..909d4e402 100644
--- a/bolt-sidecar/bin/sidecar.rs
+++ b/bolt-sidecar/bin/sidecar.rs
@@ -18,7 +18,16 @@ async fn main() -> Result<()> {
     if opts.signing.private_key.is_some() {
         match SidecarDriver::with_local_signer(&opts).await {
             Ok(driver) => driver.run_forever().await,
-            Err(err) => bail!("Failed to initialize the sidecar driver: {:?}", err),
+            Err(err) => {
+                bail!("Failed to initialize the sidecar driver with local signer: {:?}", err)
+            }
+        }
+    } else if opts.signing.keystore_password.is_some() {
+        match SidecarDriver::with_keystore_signer(&opts).await {
+            Ok(driver) => driver.run_forever().await,
+            Err(err) => {
+                bail!("Failed to initialize the sidecar driver with keystore signer: {:?}", err)
+            }
         }
     } else {
         match SidecarDriver::with_commit_boost_signer(&opts).await {
diff --git a/bolt-sidecar/src/driver.rs b/bolt-sidecar/src/driver.rs
index 4ce5c43db..060120671 100644
--- a/bolt-sidecar/src/driver.rs
+++ b/bolt-sidecar/src/driver.rs
@@ -21,7 +21,7 @@ use crate::{
         CommitmentRequest, ConstraintsMessage, FetchPayloadRequest, LocalPayloadFetcher,
         SignedConstraints, TransactionExt,
     },
-    signer::local::LocalSigner,
+    signer::{keystore::KeystoreSigner, local::LocalSigner},
     start_builder_proxy_server,
     state::{fetcher::StateFetcher, ConsensusState, ExecutionState, HeadTracker, StateClient},
     telemetry::ApiMetrics,
@@ -61,7 +61,7 @@ impl fmt::Debug for SidecarDriver<StateClient, PrivateKeySigner> {
 }
 
 impl SidecarDriver<StateClient, PrivateKeySigner> {
-    /// Create a new sidecar driver with the given [Config] and private key signer.
+    /// Create a new sidecar driver with the given [Opts] and private key signer.
     pub async fn with_local_signer(opts: &Opts) -> eyre::Result<Self> {
         // The default state client simply uses the execution API URL to fetch state updates.
         let state_client = StateClient::new(opts.execution_api_url.clone());
@@ -80,8 +80,27 @@ impl SidecarDriver<StateClient, PrivateKeySigner> {
     }
 }
 
+impl SidecarDriver<StateClient, PrivateKeySigner> {
+    /// Create a new sidecar driver with the given [Opts] and keystore signer.
+    pub async fn with_keystore_signer(opts: &Opts) -> eyre::Result<Self> {
+        // The default state client simply uses the execution API URL to fetch state updates.
+        let state_client = StateClient::new(opts.execution_api_url.clone());
+
+        let keystore_signer = SignerBLS::Keystore(KeystoreSigner::new(
+            None,
+            opts.signing.keystore_password.as_ref().expect("keystore password").as_ref(),
+        )?);
+
+        // Commitment responses are signed with a regular Ethereum wallet private key.
+        // This is now generated randomly because slashing is not yet implemented.
+        let commitment_signer = PrivateKeySigner::random();
+
+        Self::from_components(opts, keystore_signer, commitment_signer, state_client).await
+    }
+}
+
 impl SidecarDriver<StateClient, CommitBoostSigner> {
-    /// Create a new sidecar driver with the given [Config] and commit-boost signer.
+    /// Create a new sidecar driver with the given [Opts] and commit-boost signer.
     pub async fn with_commit_boost_signer(opts: &Opts) -> eyre::Result<Self> {
         // The default state client simply uses the execution API URL to fetch state updates.
         let state_client = StateClient::new(opts.execution_api_url.clone());
diff --git a/bolt-sidecar/src/signer/keystore.rs b/bolt-sidecar/src/signer/keystore.rs
index 9652a603a..e05373503 100644
--- a/bolt-sidecar/src/signer/keystore.rs
+++ b/bolt-sidecar/src/signer/keystore.rs
@@ -15,6 +15,8 @@ use lighthouse_eth2_keystore::Keystore;
 
 use crate::crypto::bls::BLSSig;
 
+pub const KEYSTORES_DEFAULT_PATH: &str = "keys";
+
 #[derive(Clone)]
 pub struct KeystoreSigner {
     keypairs: Vec<Keypair>,
@@ -84,7 +86,7 @@ impl Debug for KeystoreSigner {
 fn keystore_paths(keys_path: Option<&str>) -> Result<Vec<PathBuf>, eyre::Error> {
     // Create the path to the keystore directory, starting from the root of the project
     let project_root = env!("CARGO_MANIFEST_DIR");
-    let keys_path = Path::new(project_root).join(keys_path.unwrap_or("keys"));
+    let keys_path = Path::new(project_root).join(keys_path.unwrap_or(KEYSTORES_DEFAULT_PATH));
 
     let json_extension = OsString::from("json");