Add Signer to validator client

eth2/block_producer/src/lib.rs

@@ -1,11 +1,10 @@
-#[cfg(test)]
-mod test_node;
+pub mod test_utils;
 mod traits;
 
 use slot_clock::SlotClock;
 use spec::ChainSpec;
 use std::sync::{Arc, RwLock};
-use types::BeaconBlock;
+use types::{BeaconBlock, Hash256, ProposalSignedData};
 
 pub use self::traits::{BeaconNode, BeaconNodeError, DutiesReader, DutiesReaderError, Signer};
 
@@ -23,6 +22,8 @@ pub enum PollOutcome {
     SlotAlreadyProcessed(u64),
     /// The Beacon Node was unable to produce a block at that slot.
     BeaconNodeUnableToProduceBlock(u64),
+    /// The signer failed to sign the message.
+    SignerRejection(u64),
 }
 
 #[derive(Debug, PartialEq)]
@@ -123,9 +124,12 @@ impl<T: SlotClock, U: BeaconNode, V: DutiesReader, W: Signer> BlockProducer<T, U
     fn produce_block(&mut self, slot: u64) -> Result<PollOutcome, Error> {
         if let Some(block) = self.beacon_node.produce_beacon_block(slot)? {
             if self.safe_to_produce(&block) {
-                let block = self.sign_block(block);
-                self.beacon_node.publish_beacon_block(block)?;
-                Ok(PollOutcome::BlockProduced(slot))
+                if let Some(block) = self.sign_block(block) {
+                    self.beacon_node.publish_beacon_block(block)?;
+                    Ok(PollOutcome::BlockProduced(slot))
+                } else {
+                    Ok(PollOutcome::SignerRejection(slot))
+                }
             } else {
                 Ok(PollOutcome::SlashableBlockNotProduced(slot))
             }
@@ -138,11 +142,30 @@ impl<T: SlotClock, U: BeaconNode, V: DutiesReader, W: Signer> BlockProducer<T, U
     ///
     /// Important: this function will not check to ensure the block is not slashable. This must be
     /// done upstream.
-    fn sign_block(&mut self, block: BeaconBlock) -> BeaconBlock {
-        // TODO: sign the block
-        // https://github.com/sigp/lighthouse/issues/160
+    fn sign_block(&mut self, mut block: BeaconBlock) -> Option<BeaconBlock> {
         self.store_produce(&block);
-        block
+
+        let proposal_root = {
+            let block_without_signature_root = {
+                let mut block_without_signature = block.clone();
+                block_without_signature.signature = self.spec.empty_signature.clone();
+                block_without_signature.canonical_root()
+            };
+            let proposal = ProposalSignedData {
+                slot: block.slot,
+                shard: self.spec.beacon_chain_shard_number,
+                block_root: block_without_signature_root,
+            };
+            hash_tree_root(&proposal)
+        };
+
+        match self.signer.bls_sign(&proposal_root[..]) {
+            None => None,
+            Some(signature) => {
+                block.signature = signature;
+                Some(block)
+            }
+        }
     }
 
     /// Returns `true` if signing a block is safe (non-slashable).
@@ -167,6 +190,11 @@ impl<T: SlotClock, U: BeaconNode, V: DutiesReader, W: Signer> BlockProducer<T, U
     }
 }
 
+fn hash_tree_root<T>(_input: &T) -> Hash256 {
+    // TODO: stubbed out.
+    Hash256::zero()
+}
+
 impl From<BeaconNodeError> for Error {
     fn from(e: BeaconNodeError) -> Error {
         Error::BeaconNodeError(e)
@@ -175,13 +203,12 @@ impl From<BeaconNodeError> for Error {
 
 #[cfg(test)]
 mod tests {
-    use super::test_node::TestBeaconNode;
+    use super::test_utils::{TestBeaconNode, TestEpochMap, TestSigner};
     use super::*;
     use slot_clock::TestingSlotClock;
-    use std::collections::HashMap;
     use types::{
         test_utils::{SeedableRng, TestRandom, XorShiftRng},
-        Signature,
+        Keypair,
     };
 
     // TODO: implement more thorough testing.
@@ -189,31 +216,6 @@ mod tests {
     //
     // These tests should serve as a good example for future tests.
 
-    type EpochMap = HashMap<u64, u64>;
-
-    impl DutiesReader for EpochMap {
-        fn is_block_production_slot(
-            &self,
-            epoch: u64,
-            slot: u64,
-        ) -> Result<bool, DutiesReaderError> {
-            match self.get(&epoch) {
-                Some(s) if *s == slot => Ok(true),
-                Some(s) if *s != slot => Ok(false),
-                _ => Err(DutiesReaderError::UnknownEpoch),
-            }
-        }
-    }
-
-    struct TestSigner();
-
-    impl Signer for TestSigner {
-        fn bls_sign(_message: &[u8]) -> Option<Signature> {
-            let mut rng = XorShiftRng::from_seed([42; 16]);
-            Some(Signature::random_for_test(&mut rng))
-        }
-    }
-
     #[test]
     pub fn polling() {
         let mut rng = XorShiftRng::from_seed([42; 16]);
@@ -221,9 +223,9 @@ mod tests {
         let spec = Arc::new(ChainSpec::foundation());
         let slot_clock = Arc::new(RwLock::new(TestingSlotClock::new(0)));
         let beacon_node = Arc::new(TestBeaconNode::default());
-        let signer = Arc::new(TestSigner());
+        let signer = Arc::new(TestSigner::new(Keypair::random()));
 
-        let mut epoch_map = EpochMap::new();
+        let mut epoch_map = TestEpochMap::new();
         let produce_slot = 100;
         let produce_epoch = produce_slot / spec.epoch_length;
         epoch_map.insert(produce_epoch, produce_slot);

eth2/block_producer/src/test_utils/beacon_node.rs

@@ -1,4 +1,4 @@
-use super::traits::{BeaconNode, BeaconNodeError};
+use crate::traits::{BeaconNode, BeaconNodeError};
 use std::sync::RwLock;
 use types::BeaconBlock;
 

eth2/block_producer/src/test_utils/epoch_map.rs

@@ -0,0 +1,14 @@
+use crate::{DutiesReader, DutiesReaderError};
+use std::collections::HashMap;
+
+pub type TestEpochMap = HashMap<u64, u64>;
+
+impl DutiesReader for TestEpochMap {
+    fn is_block_production_slot(&self, epoch: u64, slot: u64) -> Result<bool, DutiesReaderError> {
+        match self.get(&epoch) {
+            Some(s) if *s == slot => Ok(true),
+            Some(s) if *s != slot => Ok(false),
+            _ => Err(DutiesReaderError::UnknownEpoch),
+        }
+    }
+}

eth2/block_producer/src/test_utils/mod.rs

@@ -0,0 +1,7 @@
+mod beacon_node;
+mod epoch_map;
+mod signer;
+
+pub use self::beacon_node::TestBeaconNode;
+pub use self::epoch_map::TestEpochMap;
+pub use self::signer::TestSigner;

eth2/block_producer/src/test_utils/signer.rs

@@ -0,0 +1,31 @@
+use crate::traits::Signer;
+use std::sync::RwLock;
+use types::{Keypair, Signature};
+
+/// A test-only struct used to simulate a Beacon Node.
+pub struct TestSigner {
+    keypair: Keypair,
+    should_sign: RwLock<bool>,
+}
+
+impl TestSigner {
+    /// Produce a new TestSigner with signing enabled by default.
+    pub fn new(keypair: Keypair) -> Self {
+        Self {
+            keypair,
+            should_sign: RwLock::new(true),
+        }
+    }
+
+    /// If set to `false`, the service will refuse to sign all messages. Otherwise, all messages
+    /// will be signed.
+    pub fn enable_signing(&self, enabled: bool) {
+        *self.should_sign.write().unwrap() = enabled;
+    }
+}
+
+impl Signer for TestSigner {
+    fn bls_sign(&self, message: &[u8]) -> Option<Signature> {
+        Some(Signature::new(message, &self.keypair.sk))
+    }
+}

eth2/block_producer/src/traits.rs

@@ -18,16 +18,18 @@ pub trait BeaconNode: Send + Sync {
     fn publish_beacon_block(&self, block: BeaconBlock) -> Result<bool, BeaconNodeError>;
 }
 
+#[derive(Debug, PartialEq, Clone)]
 pub enum DutiesReaderError {
     UnknownEpoch,
     Poisoned,
 }
 
-/// Provides methods for a validator to determine their responsibilities for some slot.
+/// Informs a validator of their duties (e.g., block production).
 pub trait DutiesReader: Send + Sync {
     fn is_block_production_slot(&self, epoch: u64, slot: u64) -> Result<bool, DutiesReaderError>;
 }
 
+/// Signs message using an internally-maintained private key.
 pub trait Signer {
-    fn bls_sign(message: &[u8]) -> Option<Signature>;
+    fn bls_sign(&self, message: &[u8]) -> Option<Signature>;
 }

validator_client/src/block_producer_service/service.rs

@@ -1,17 +1,17 @@
 use block_producer::{
-    BeaconNode, BlockProducer, DutiesReader, PollOutcome as BlockProducerPollOutcome,
+    BeaconNode, BlockProducer, DutiesReader, PollOutcome as BlockProducerPollOutcome, Signer,
 };
 use slog::{error, info, warn, Logger};
 use slot_clock::SlotClock;
 use std::time::Duration;
 
-pub struct BlockProducerService<T: SlotClock, U: BeaconNode, V: DutiesReader> {
-    pub block_producer: BlockProducer<T, U, V>,
+pub struct BlockProducerService<T: SlotClock, U: BeaconNode, V: DutiesReader, W: Signer> {
+    pub block_producer: BlockProducer<T, U, V, W>,
     pub poll_interval_millis: u64,
     pub log: Logger,
 }
 
-impl<T: SlotClock, U: BeaconNode, V: DutiesReader> BlockProducerService<T, U, V> {
+impl<T: SlotClock, U: BeaconNode, V: DutiesReader, W: Signer> BlockProducerService<T, U, V, W> {
     /// Run a loop which polls the block producer each `poll_interval_millis` millseconds.
     ///
     /// Logs the results of the polls.
@@ -39,6 +39,9 @@ impl<T: SlotClock, U: BeaconNode, V: DutiesReader> BlockProducerService<T, U, V>
                 Ok(BlockProducerPollOutcome::BeaconNodeUnableToProduceBlock(slot)) => {
                     error!(self.log, "Beacon node unable to produce block"; "slot" => slot)
                 }
+                Ok(BlockProducerPollOutcome::SignerRejection(slot)) => {
+                    error!(self.log, "The cryptographic signer refused to sign the block"; "slot" => slot)
+                }
             };
 
             std::thread::sleep(Duration::from_millis(self.poll_interval_millis));

validator_client/src/main.rs

@@ -1,7 +1,7 @@
 use self::block_producer_service::{BeaconBlockGrpcClient, BlockProducerService};
 use self::duties::{DutiesManager, DutiesManagerService, EpochDutiesMap};
 use crate::config::ClientConfig;
-use block_producer::BlockProducer;
+use block_producer::{test_utils::TestSigner, BlockProducer};
 use bls::Keypair;
 use clap::{App, Arg};
 use grpcio::{ChannelBuilder, EnvBuilder};
@@ -139,12 +139,14 @@ fn main() {
         // Spawn a new thread to perform block production for the validator.
         let producer_thread = {
             let spec = spec.clone();
+            let signer = Arc::new(TestSigner::new(keypair.clone()));
             let duties_map = duties_map.clone();
             let slot_clock = slot_clock.clone();
             let log = log.clone();
             let client = Arc::new(BeaconBlockGrpcClient::new(beacon_block_grpc_client.clone()));
             thread::spawn(move || {
-                let block_producer = BlockProducer::new(spec, duties_map, slot_clock, client);
+                let block_producer =
+                    BlockProducer::new(spec, duties_map, slot_clock, client, signer);
                 let mut block_producer_service = BlockProducerService {
                     block_producer,
                     poll_interval_millis,