feat: sync committee proof server (#100)

* feat: sync committee proof server

docs: rust doc + recompile program

feat: compile program

feat: proper count for signers

feat: remove setup logger

feat: committee change proof server

* docs: fix necessary RUSTFLAGS

* Update ethereum/docs/src/run/setup_proof_server.md

Co-authored-by: wwared <[email protected]>

* refactor: integrate review

Co-authored-by: wwared <[email protected]>

---------

Co-authored-by: wwared <[email protected]>

ethereum/core/Cargo.toml

@@ -11,6 +11,7 @@ anyhow = { workspace = true }
 bls12_381 = { workspace = true, features = ["experimental"] }
 hex = { workspace = true }
 getset = { workspace = true }
+serde = { workspace = true, features = ["derive"] }
 sha2 = { workspace = true }
 thiserror = { workspace = true }
 tiny-keccak = { workspace = true, features = ["keccak"] }

ethereum/core/src/crypto/sig.rs

@@ -274,7 +274,7 @@ pub const SYNC_AGGREGATE_BYTES_LEN: usize = SYNC_COMMITTEE_SIZE / 8 + SIG_LEN;
 /// index who signed the message as bits and the actual signature.
 ///
 /// From [the Altaïr specifications](https://github.com/ethereum/consensus-specs/blob/81f3ea8322aff6b9fb15132d050f8f98b16bdba4/specs/altair/beacon-chain.md#syncaggregate).
-#[derive(Debug, Clone, Getters)]
+#[derive(Debug, Clone, Eq, PartialEq, Getters)]
 #[getset(get = "pub")]
 pub struct SyncAggregate {
     sync_committee_bits: [u8; SYNC_COMMITTEE_SIZE],

ethereum/core/src/types/store.rs

@@ -180,7 +180,8 @@ impl LightClientStore {
             .sync_aggregate()
             .sync_committee_bits()
             .iter()
-            .sum::<u8>()
+            .map(|&bit| u64::from(bit))
+            .sum::<u64>()
             < 1
         {
             return Err(ConsensusError::InsufficientSigners);

ethereum/core/src/types/update.rs

@@ -30,7 +30,7 @@ pub const UPDATE_BASE_BYTES_LEN: usize = LIGHT_CLIENT_HEADER_BASE_BYTES_LEN * 2
 /// A data structure containing the necessary data for a light client to update its state from the Beacon chain.
 ///
 /// From [the Altaïr specifications](https://github.com/ethereum/consensus-specs/blob/81f3ea8322aff6b9fb15132d050f8f98b16bdba4/specs/altair/light-client/sync-protocol.md#lightclientupdate).
-#[derive(Debug, Clone, Getters)]
+#[derive(Debug, Clone, Eq, PartialEq, Getters)]
 #[getset(get = "pub")]
 pub struct Update {
     attested_header: LightClientHeader,

ethereum/docs/src/run/setup_client.md

@@ -10,5 +10,5 @@ With our deployment machine properly configured, we can run the client.
 ```bash
 git clone [email protected]:lurk-lab/zk-light-clients.git && \
   cd zk-light-clients/ethereum && \
-  RUST_LOG="debug" cargo +nightly-2024-05-31 run -p light-client --release --bin client -- -c <CHECKPOINT_PROVIDER_ADDRESS> -b <BEACON_NODE_ADDRESS>
+  RUST_LOG="debug" cargo +nightly-2024-05-31 run -p light-client --release --bin client -- -c <CHECKPOINT_PROVIDER_ADDRESS> -b <BEACON_NODE_ADDRESS> -p <PROOF_SERVER_ADDRESS>
 ```

ethereum/docs/src/run/setup_proof_server.md

@@ -0,0 +1,42 @@
+# Deploy the Proof Server
+
+We have two components to deploy for the Proof Server to work as intended. The primary and the secondary server.
+There is no particular order in which they should be deployed, but here we will deploy the secondary and then
+the primary.
+
+For best results, the primary and secondary servers should be deployed to **different server instances**, so that
+proof generation can happen in parallel if necessary.
+
+## Requirements
+
+Make sure to finish the [initial configuration](./configuration.md) first.
+
+## Environment variables
+
+- `RUSTFLAGS="-C target-cpu=native -C opt-level=3"`:
+    - `-C target-cpu=native`: This will ensure that the binary is optimized
+      for the CPU it is running on. This is very important
+      for [plonky3](https://github.com/plonky3/plonky3?tab=readme-ov-file#cpu-features) performance.
+    - `-C opt-level=3`: This turns on the maximum level of compiler optimizations.
+    - This can also be configured in `~/.cargo/config.toml` instead by adding:
+        ```toml
+        [target.'cfg(all())']
+        rustflags = ["-C", "target-cpu=native", "-C", "opt-level=3"]
+        ```
+
+Make sure to launch the proof servers with `cargo +nightly-2024-05-31`.
+
+> **Note**
+>
+> One can also set the `RUST_LOG` environment variable to `debug` to get more information
+> about the execution of the server.
+
+## Deploy the primary server
+
+Finally, once the primary server is configured in the same fashion, run it:
+
+```bash
+git clone [email protected]:lurk-lab/zk-light-clients.git && \
+  cd zk-light-clients/ethereum/light-client && \
+  SHARD_BATCH_SIZE=0 RUSTFLAGS="-C target-cpu=native -C opt-level=3" cargo +nightly-2024-05-31 run --release --bin server_primary -- -a <NETWORK_ADDESS> --snd-addr <SECONDARY_SERVER_ADDRESS>
+```

ethereum/light-client/Cargo.toml

@@ -14,6 +14,7 @@ hex = { workspace = true }
 log = { workspace = true }
 reqwest = { workspace = true, features = ["json"] }
 serde = { workspace = true, features = ["derive"] }
+serde_json = { workspace = true }
 thiserror = { workspace = true }
 tokio = { workspace = true, features = ["full"] }
 # LC crates
@@ -22,9 +23,6 @@ ethereum-programs = { path = "../ethereum-programs" }
 # Sphinx crates
 sphinx-sdk = { workspace = true }
 
-[dev-dependencies]
-serde_json = { workspace = true }
-
 [[bin]]
 name = "client"
 path = "src/bin/client.rs"

ethereum/light-client/src/bin/client.rs

@@ -1,11 +1,14 @@
 // Copyright (c) Yatima, Inc.
 // SPDX-License-Identifier: Apache-2.0
 
+use anyhow::Result;
 use clap::Parser;
-use ethereum_lc_core::merkle::Merkleized;
+use ethereum_lc::client::Client;
+use ethereum_lc::proofs::ProvingMode;
 use ethereum_lc_core::types::store::LightClientStore;
 use ethereum_lc_core::types::utils::calc_sync_period;
 use log::info;
+use std::sync::Arc;
 
 /// The maximum number of light client updates that can be requested.
 ///
@@ -26,22 +29,52 @@ struct Cli {
     /// It is recommended to use https://www.lightclientdata.org
     #[arg(short, long)]
     beacon_node_address: String,
+
+    /// The address of the proof server
+    #[arg(short, long)]
+    proof_server_address: String,
+}
+
+pub struct ClientState {
+    client: Client,
+    store: LightClientStore,
 }
 
 #[tokio::main]
 async fn main() {
     let Cli {
         checkpoint_provider_address,
         beacon_node_address,
+        proof_server_address,
         ..
     } = Cli::parse();
 
     // Initialize the logger.
     env_logger::init();
 
+    let checkpoint_provider_address = Arc::new(checkpoint_provider_address);
+    let beacon_node_address = Arc::new(beacon_node_address);
+    let proof_server_address = Arc::new(proof_server_address);
+
+    let _state = initialize_light_client(
+        checkpoint_provider_address,
+        beacon_node_address,
+        proof_server_address,
+    )
+    .await;
+}
+
+async fn initialize_light_client(
+    checkpoint_provider_address: Arc<String>,
+    beacon_node_address: Arc<String>,
+    proof_server_address: Arc<String>,
+) -> Result<ClientState> {
     // Instantiate client.
-    let client =
-        ethereum_lc::client::Client::new(&checkpoint_provider_address, &beacon_node_address);
+    let client = Client::new(
+        &checkpoint_provider_address,
+        &beacon_node_address,
+        &proof_server_address,
+    );
 
     info!("Fetching latest state checkpoint and bootstrap data...");
 
@@ -79,15 +112,18 @@ async fn main() {
     .try_into()
     .expect("Failed to convert checkpoint bytes to Bytes32");
 
-    let mut store = LightClientStore::initialize(trusted_block_root, &bootstrap)
+    let store = LightClientStore::initialize(trusted_block_root, &bootstrap)
         .expect("Could not initialize the store based on bootstrap data");
 
+    let mut client_state = ClientState { client, store };
+
     info!("Fetching updates...");
 
     // Fetch updates
     let sync_period = calc_sync_period(bootstrap.header().beacon().slot());
 
-    let update_response = client
+    let update_response = client_state
+        .client
         .get_update_data(sync_period, MAX_REQUEST_LIGHT_CLIENT_UPDATES)
         .await
         .expect("Failed to fetch update data");
@@ -109,35 +145,24 @@ async fn main() {
             info!("Sync period changed, updating store...");
         }
 
-        store
+        let proof = client_state
+            .client
+            .prove_committee_change(ProvingMode::STARK, &client_state.store, update.update())
+            .await
+            .expect("Failed to prove committee change");
+
+        client_state
+            .client
+            .verify_committee_change(proof.clone())
+            .await
+            .expect("Failed to prove committee change");
+
+        // TODO this is redundant, to simplify
+        client_state
+            .store
             .process_light_client_update(update.update())
-            .expect("Failed to process update");
-
-        assert_eq!(
-            store
-                .next_sync_committee()
-                .clone()
-                .unwrap()
-                .hash_tree_root()
-                .unwrap(),
-            update
-                .update()
-                .next_sync_committee()
-                .hash_tree_root()
-                .unwrap()
-        );
-
-        if calc_sync_period(bootstrap.header().beacon().slot())
-            != calc_sync_period(update.update().attested_header().beacon().slot())
-        {
-            assert_eq!(
-                store.finalized_header().hash_tree_root().unwrap(),
-                update.update().finalized_header().hash_tree_root().unwrap()
-            );
-            assert_eq!(
-                store.optimistic_header().hash_tree_root().unwrap(),
-                update.update().finalized_header().hash_tree_root().unwrap()
-            )
-        }
+            .unwrap()
     }
+
+    Ok(client_state)
 }

ethereum/light-client/src/bin/server_primary.rs

@@ -1,5 +1,77 @@
 // Copyright (c) Yatima, Inc.
 // SPDX-License-Identifier: Apache-2.0
 
-#[allow(clippy::missing_const_for_fn)]
-fn main() {}
+use anyhow::{Error, Result};
+use clap::Parser;
+use ethereum_lc::proofs::committee_change::CommitteeChangeProver;
+use ethereum_lc::proofs::Prover;
+use ethereum_lc::types::network::Request;
+use ethereum_lc::utils::{read_bytes, write_bytes};
+use log::{error, info};
+use std::sync::Arc;
+use tokio::net::TcpListener;
+use tokio::task::spawn_blocking;
+
+#[derive(Parser)]
+struct Cli {
+    /// Address of this server. E.g. 127.0.0.1:1234
+    #[arg(short, long)]
+    addr: String,
+
+    /// Address of the secondary server. E.g. 127.0.0.1:4321
+    #[arg(long)]
+    snd_addr: String,
+}
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    let Cli { addr, .. } = Cli::parse();
+
+    env_logger::init();
+
+    let listener = TcpListener::bind(addr).await?;
+    info!("Server is running on {}", listener.local_addr()?);
+
+    let committee_prover = Arc::new(CommitteeChangeProver::new());
+
+    loop {
+        let (mut client_stream, _) = listener.accept().await?;
+        info!("Received a connection");
+
+        let committee_prover = committee_prover.clone();
+
+        tokio::spawn(async move {
+            info!("Awaiting request");
+            let request_bytes = read_bytes(&mut client_stream).await?;
+            info!("Request received");
+
+            info!("Deserializing request");
+            match Request::from_bytes(&request_bytes) {
+                Ok(request) => match request {
+                    Request::ProveCommitteeChange(boxed) => {
+                        info!("Start proving");
+                        let proof_handle = spawn_blocking(move || {
+                            let (proving_mode, inputs) = boxed.as_ref();
+                            committee_prover.prove(inputs.clone(), proving_mode.clone())
+                        });
+                        let proof = proof_handle.await??;
+                        info!("Proof generated. Serializing");
+                        let proof_bytes = proof.to_bytes()?;
+                        info!("Sending proof");
+                        write_bytes(&mut client_stream, &proof_bytes).await?;
+                        info!("Proof sent");
+                    }
+                    Request::VerifyCommitteeChange(proof) => {
+                        write_bytes(
+                            &mut client_stream,
+                            &[u8::from(committee_prover.verify(&proof).is_ok())],
+                        )
+                        .await?;
+                    }
+                },
+                Err(err) => error!("Failed to deserialize request object: {err}"),
+            }
+            Ok::<(), Error>(())
+        });
+    }
+}