Common EngineSigner (#4189)

* remove register_account_provider

* build rpc module

* new dummy client

* common EngineSigner struct

* from -> into

* return Signature, docs

ethcore/src/engines/authority_round.rs

@@ -36,8 +36,9 @@ use io::{IoContext, IoHandler, TimerToken, IoService};
 use env_info::EnvInfo;
 use builtin::Builtin;
 use client::{Client, EngineClient};
-use super::validator_set::{ValidatorSet, new_validator_set};
 use state::CleanupMode;
+use super::signer::EngineSigner;
+use super::validator_set::{ValidatorSet, new_validator_set};
 
 /// `AuthorityRound` params.
 #[derive(Debug, PartialEq)]
@@ -78,8 +79,7 @@ pub struct AuthorityRound {
 	step: AtomicUsize,
 	proposed: AtomicBool,
 	client: RwLock<Option<Weak<EngineClient>>>,
-	account_provider: Mutex<Arc<AccountProvider>>,
-	password: RwLock<Option<String>>,
+	signer: EngineSigner,
 	validators: Box<ValidatorSet + Send + Sync>,
 }
 
@@ -117,8 +117,7 @@ impl AuthorityRound {
 				step: AtomicUsize::new(initial_step),
 				proposed: AtomicBool::new(false),
 				client: RwLock::new(None),
-				account_provider: Mutex::new(Arc::new(AccountProvider::transient_provider())),
-				password: RwLock::new(None),
+				signer: Default::default(),
 				validators: new_validator_set(our_params.validators),
 			});
 		// Do not initialize timeouts for tests.
@@ -234,11 +233,10 @@ impl Engine for AuthorityRound {
 		let header = block.header();
 		let step = self.step.load(AtomicOrdering::SeqCst);
 		if self.is_step_proposer(step, header.author()) {
-			let ap = self.account_provider.lock();
-			if let Ok(signature) = ap.sign(*header.author(), self.password.read().clone(), header.bare_hash()) {
+			if let Ok(signature) = self.signer.sign(header.bare_hash()) {
 				trace!(target: "poa", "generate_seal: Issuing a block for step {}.", step);
 				self.proposed.store(true, AtomicOrdering::SeqCst);
-				return Seal::Regular(vec![encode(&step).to_vec(), encode(&(&*signature as &[u8])).to_vec()]);
+				return Seal::Regular(vec![encode(&step).to_vec(), encode(&(&H520::from(signature) as &[u8])).to_vec()]);
 			} else {
 				warn!(target: "poa", "generate_seal: FAIL: Accounts secret key unavailable.");
 			}
@@ -330,9 +328,7 @@ impl Engine for AuthorityRound {
 	}
 
 	fn set_signer(&self, ap: Arc<AccountProvider>, address: Address, password: String) {
-		*self.account_provider.lock() = ap;	
-		*self.password.write() = Some(password);
-		debug!(target: "poa", "Setting Engine signer to {}", address);
+		self.signer.set(ap, address, password);
 	}
 }
 

ethcore/src/engines/basic_authority.rs

@@ -30,6 +30,7 @@ use evm::Schedule;
 use ethjson;
 use header::Header;
 use client::Client;
+use super::signer::EngineSigner;
 use super::validator_set::{ValidatorSet, new_validator_set};
 
 /// `BasicAuthority` params.
@@ -56,8 +57,7 @@ pub struct BasicAuthority {
 	params: CommonParams,
 	gas_limit_bound_divisor: U256,
 	builtins: BTreeMap<Address, Builtin>,
-	account_provider: Mutex<Arc<AccountProvider>>,
-	password: RwLock<Option<String>>,
+	signer: EngineSigner,
 	validators: Box<ValidatorSet + Send + Sync>,
 }
 
@@ -69,8 +69,7 @@ impl BasicAuthority {
 			gas_limit_bound_divisor: our_params.gas_limit_bound_divisor,
 			builtins: builtins,
 			validators: new_validator_set(our_params.validators),
-			account_provider: Mutex::new(Arc::new(AccountProvider::transient_provider())),
-			password: RwLock::new(None),
+			signer: Default::default(),
 		}
 	}
 }
@@ -110,14 +109,12 @@ impl Engine for BasicAuthority {
 
 	/// Attempt to seal the block internally.
 	fn generate_seal(&self, block: &ExecutedBlock) -> Seal {
-		let ref ap = *self.account_provider.lock();
 		let header = block.header();
 		let author = header.author();
 		if self.validators.contains(author) {
-			let message = header.bare_hash();
 			// account should be pernamently unlocked, otherwise sealing will fail
-			if let Ok(signature) = ap.sign(*author, self.password.read().clone(), message) {
-				return Seal::Regular(vec![::rlp::encode(&(&*signature as &[u8])).to_vec()]);
+			if let Ok(signature) = self.signer.sign(header.bare_hash()) {
+				return Seal::Regular(vec![::rlp::encode(&(&H520::from(signature) as &[u8])).to_vec()]);
 			} else {
 				trace!(target: "basicauthority", "generate_seal: FAIL: accounts secret key unavailable");
 			}
@@ -171,9 +168,8 @@ impl Engine for BasicAuthority {
 		self.validators.register_call_contract(client);
 	}
 
-	fn set_signer(&self, ap: Arc<AccountProvider>, _address: Address, password: String) {
-		*self.password.write() = Some(password);
-		*self.account_provider.lock() = ap;
+	fn set_signer(&self, ap: Arc<AccountProvider>, address: Address, password: String) {
+		self.signer.set(ap, address, password);
 	}
 }
 

ethcore/src/engines/mod.rs

@@ -22,6 +22,7 @@ mod basic_authority;
 mod authority_round;
 mod tendermint;
 mod validator_set;
+mod signer;
 
 pub use self::null_engine::NullEngine;
 pub use self::instant_seal::InstantSeal;

ethcore/src/engines/signer.rs

@@ -0,0 +1,63 @@
+// Copyright 2015, 2016 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! A signer used by Engines which need to sign messages.
+
+use util::{Arc, Mutex, RwLock, H256, Address};
+use ethkey::Signature;
+use account_provider::{self, AccountProvider};
+
+/// Everything that an Engine needs to sign messages.
+pub struct EngineSigner {
+	account_provider: Mutex<Arc<AccountProvider>>,
+	address: RwLock<Address>,
+	password: RwLock<Option<String>>,
+}
+
+impl Default for EngineSigner {
+	fn default() -> Self {
+		EngineSigner {
+			account_provider: Mutex::new(Arc::new(AccountProvider::transient_provider())),
+			address: Default::default(),
+			password: Default::default(),
+		}
+	}
+}
+
+impl EngineSigner {
+	/// Set up the signer to sign with given address and password.
+	pub fn set(&self, ap: Arc<AccountProvider>, address: Address, password: String) {
+		*self.account_provider.lock() = ap;
+		*self.address.write()	= address;
+		*self.password.write() = Some(password);
+		debug!(target: "poa", "Setting Engine signer to {}", address);
+	}
+
+	/// Sign a consensus message hash.
+	pub fn sign(&self, hash: H256) -> Result<Signature, account_provider::Error> {
+		self.account_provider.lock().sign(*self.address.read(), self.password.read().clone(), hash)
+	}
+
+	/// Signing address.
+	pub fn address(&self) -> Address {
+		self.address.read().clone()
+	}
+
+	/// Check if the given address is the signing address.
+	pub fn is_address(&self, address: &Address) -> bool {
+		*self.address.read() == *address
+	}
+}

ethcore/src/engines/tendermint/mod.rs

@@ -46,6 +46,7 @@ use views::HeaderView;
 use evm::Schedule;
 use state::CleanupMode;
 use io::IoService;
+use super::signer::EngineSigner;
 use super::validator_set::{ValidatorSet, new_validator_set};
 use self::message::*;
 use self::transition::TransitionHandler;
@@ -81,10 +82,6 @@ pub struct Tendermint {
 	step_service: IoService<Step>,
 	client: RwLock<Option<Weak<EngineClient>>>,
 	block_reward: U256,
-	/// Address to be used as authority.
-	authority: RwLock<Address>,
-	/// Password used for signing messages.
-	password: RwLock<Option<String>>,
 	/// Blockchain height.
 	height: AtomicUsize,
 	/// Consensus round.
@@ -94,7 +91,7 @@ pub struct Tendermint {
 	/// Vote accumulator.
 	votes: VoteCollector,
 	/// Used to sign messages and proposals.
-	account_provider: Mutex<Arc<AccountProvider>>,
+	signer: EngineSigner,
 	/// Message for the last PoLC.
 	lock_change: RwLock<Option<ConsensusMessage>>,
 	/// Last lock round.
@@ -116,13 +113,11 @@ impl Tendermint {
 				client: RwLock::new(None),
 				step_service: IoService::<Step>::start()?,
 				block_reward: our_params.block_reward,
-				authority: RwLock::new(Address::default()),
-				password: RwLock::new(None),
 				height: AtomicUsize::new(1),
 				round: AtomicUsize::new(0),
 				step: RwLock::new(Step::Propose),
 				votes: VoteCollector::new(),
-				account_provider: Mutex::new(Arc::new(AccountProvider::transient_provider())),
+				signer: Default::default(),
 				lock_change: RwLock::new(None),
 				last_lock: AtomicUsize::new(0),
 				proposal: RwLock::new(None),
@@ -158,18 +153,17 @@ impl Tendermint {
 	}
 
 	fn generate_message(&self, block_hash: Option<BlockHash>) -> Option<Bytes> {
-		let ref ap = *self.account_provider.lock();
 		let h = self.height.load(AtomicOrdering::SeqCst);
 		let r = self.round.load(AtomicOrdering::SeqCst);
 		let s = self.step.read();
 		let vote_info = message_info_rlp(&VoteStep::new(h, r, *s), block_hash);
-		let authority = self.authority.read();
-		match ap.sign(*authority, self.password.read().clone(), vote_info.sha3()).map(Into::into) {
+		match self.signer.sign(vote_info.sha3()).map(Into::into) {
 			Ok(signature) => {
 				let message_rlp = message_full_rlp(&signature, &vote_info);
 				let message = ConsensusMessage::new(signature, h, r, *s, block_hash);
-				self.votes.vote(message.clone(), &*authority);
-				debug!(target: "poa", "Generated {:?} as {}.", message, *authority);
+				let validator = self.signer.address();
+				self.votes.vote(message.clone(), &validator);
+				debug!(target: "poa", "Generated {:?} as {}.", message, validator);
 				self.handle_valid_message(&message);
 
 				Some(message_rlp)
@@ -240,7 +234,7 @@ impl Tendermint {
 				let height = self.height.load(AtomicOrdering::SeqCst);
 				if let Some(block_hash) = *self.proposal.read() {
 					// Generate seal and remove old votes.
-					if self.is_proposer(&*self.authority.read()).is_ok() {
+					if self.is_signer_proposer() {
 						if let Some(seal) = self.votes.seal_signatures(height, round, &block_hash) {
 							trace!(target: "poa", "Collected seal: {:?}", seal);
 							let seal = vec![
@@ -267,11 +261,16 @@ impl Tendermint {
 		n > self.validators.count() * 2/3
 	}
 
+	/// Find the designated for the given round.
+	fn round_proposer(&self, height: Height, round: Round) -> Address {
+		let proposer_nonce = height + round;
+		trace!(target: "poa", "Proposer nonce: {}", proposer_nonce);
+		self.validators.get(proposer_nonce)
+	}
+
 	/// Check if address is a proposer for given round.
 	fn is_round_proposer(&self, height: Height, round: Round, address: &Address) -> Result<(), EngineError> {
-		let proposer_nonce = height + round;
-		trace!(target: "poa", "is_proposer: Proposer nonce: {}", proposer_nonce);
-		let proposer = self.validators.get(proposer_nonce);
+		let proposer = self.round_proposer(height, round);
 		if proposer == *address {
 			Ok(())
 		} else {
@@ -279,9 +278,10 @@ impl Tendermint {
 		}
 	}
 
-	/// Check if address is the current proposer.
-	fn is_proposer(&self, address: &Address) -> Result<(), EngineError> {
-		self.is_round_proposer(self.height.load(AtomicOrdering::SeqCst), self.round.load(AtomicOrdering::SeqCst), address)
+	/// Check if current signer is the current proposer.
+	fn is_signer_proposer(&self) -> bool {
+		let proposer = self.round_proposer(self.height.load(AtomicOrdering::SeqCst), self.round.load(AtomicOrdering::SeqCst));
+		self.signer.is_address(&proposer)
 	}
 
 	fn is_height(&self, message: &ConsensusMessage) -> bool {
@@ -416,11 +416,10 @@ impl Engine for Tendermint {
 
 	/// Attempt to seal generate a proposal seal.
 	fn generate_seal(&self, block: &ExecutedBlock) -> Seal {
-		let ref ap = *self.account_provider.lock();
 		let header = block.header();
 		let author = header.author();
 		// Only proposer can generate seal if None was generated.
-		if self.is_proposer(author).is_err() || self.proposal.read().is_some() {
+		if !self.is_signer_proposer() || self.proposal.read().is_some() {
 			return Seal::None;
 		}
 
@@ -428,7 +427,7 @@ impl Engine for Tendermint {
 		let round = self.round.load(AtomicOrdering::SeqCst);
 		let bh = Some(header.bare_hash());
 		let vote_info = message_info_rlp(&VoteStep::new(height, round, Step::Propose), bh.clone());
-		if let Ok(signature) = ap.sign(*author, self.password.read().clone(), vote_info.sha3()).map(H520::from) {
+		if let Ok(signature) = self.signer.sign(vote_info.sha3()).map(Into::into) {
 			// Insert Propose vote.
 			debug!(target: "poa", "Submitting proposal {} at height {} round {}.", header.bare_hash(), height, round);
 			self.votes.vote(ConsensusMessage::new(signature, height, round, Step::Propose, bh), author);
@@ -557,9 +556,7 @@ impl Engine for Tendermint {
 
 	fn set_signer(&self, ap: Arc<AccountProvider>, address: Address, password: String) {
 		{
-			*self.authority.write()	= address;
-			*self.password.write() = Some(password);
-			*self.account_provider.lock() = ap;
+			self.signer.set(ap, address, password);
 		}
 		self.to_step(Step::Propose);
 	}