new simple authority engine

Cargo.lock

@@ -569,6 +569,7 @@ name = "ethkey"
 version = "0.2.0"
 dependencies = [
  "bigint 0.1.0",
+ "docopt 0.6.80 (registry+https://github.com/rust-lang/crates.io-index)",
  "eth-secp256k1 0.5.4 (git+https://github.com/ethcore/rust-secp256k1)",
  "lazy_static 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -580,6 +581,7 @@ dependencies = [
 name = "ethstore"
 version = "0.1.0"
 dependencies = [
+ "docopt 0.6.80 (registry+https://github.com/rust-lang/crates.io-index)",
  "ethcrypto 0.1.0",
  "ethkey 0.2.0",
  "itertools 0.4.13 (registry+https://github.com/rust-lang/crates.io-index)",

ethcore/src/engines/authority_round.rs

@@ -0,0 +1,320 @@
+// Copyright 2015, 2016 Ethcore (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 blockchain engine that supports a basic, non-BFT proof-of-authority.
+
+use std::sync::atomic::{AtomicUsize, Ordering as AtomicOrdering};
+use std::sync::Weak;
+use common::*;
+use ethkey::{recover, public_to_address};
+use rlp::{UntrustedRlp, View, encode, decode};
+use account_provider::AccountProvider;
+use block::*;
+use spec::CommonParams;
+use engines::Engine;
+use evm::Schedule;
+use ethjson;
+use io::{IoContext, IoHandler, TimerToken, IoService};
+use time::get_time;
+
+/// `AuthorityRound` params.
+#[derive(Debug, PartialEq)]
+pub struct AuthorityRoundParams {
+	/// Gas limit divisor.
+	pub gas_limit_bound_divisor: U256,
+	/// Time to wait before next block or authority switching.
+	pub step_duration: u64,
+	/// Valid authorities.
+	pub authorities: Vec<Address>,
+	/// Number of authorities.
+	pub authority_n: usize,
+}
+
+impl From<ethjson::spec::AuthorityRoundParams> for AuthorityRoundParams {
+	fn from(p: ethjson::spec::AuthorityRoundParams) -> Self {
+		AuthorityRoundParams {
+			gas_limit_bound_divisor: p.gas_limit_bound_divisor.into(),
+			step_duration: p.step_duration.into(),
+			authority_n: p.authorities.len(),
+			authorities: p.authorities.into_iter().map(Into::into).collect::<Vec<_>>(),
+		}
+	}
+}
+
+/// Engine using `AuthorityRound` proof-of-work consensus algorithm, suitable for Ethereum
+/// mainnet chains in the Olympic, Frontier and Homestead eras.
+pub struct AuthorityRound {
+	params: CommonParams,
+	our_params: AuthorityRoundParams,
+	builtins: BTreeMap<Address, Builtin>,
+	transistion_service: IoService<BlockArrived>,
+	step: AtomicUsize,
+}
+
+impl AuthorityRound {
+	/// Create a new instance of AuthorityRound engine
+	pub fn new(params: CommonParams, our_params: AuthorityRoundParams, builtins: BTreeMap<Address, Builtin>) -> Arc<Self> {
+		let engine = Arc::new(
+			AuthorityRound {
+				params: params,
+				our_params: our_params,
+				builtins: builtins,
+				transistion_service: IoService::<BlockArrived>::start().expect("Error creating engine timeout service"),
+				step: AtomicUsize::new(0),
+			});
+		let handler = TransitionHandler { engine: Arc::downgrade(&engine) };
+		engine.transistion_service.register_handler(Arc::new(handler)).expect("Error creating engine timeout service");
+		engine
+	}
+
+	fn proposer(&self) -> &Address {
+		let ref p = self.our_params;
+		p.authorities.get(self.step.load(AtomicOrdering::Relaxed)%p.authority_n).unwrap()
+	}
+
+	fn is_proposer(&self, address: &Address) -> bool {
+		self.proposer() == address
+	}
+}
+
+struct TransitionHandler {
+	engine: Weak<AuthorityRound>,
+}
+
+#[derive(Clone)]
+struct BlockArrived;
+
+const ENGINE_TIMEOUT_TOKEN: TimerToken = 0;
+
+impl IoHandler<BlockArrived> for TransitionHandler {
+	fn initialize(&self, io: &IoContext<BlockArrived>) {
+		if let Some(engine) = self.engine.upgrade() {
+			io.register_timer_once(ENGINE_TIMEOUT_TOKEN, engine.our_params.step_duration).expect("Error registering engine timeout");
+		}
+	}
+
+	fn timeout(&self, io: &IoContext<BlockArrived>, timer: TimerToken) {
+		if timer == ENGINE_TIMEOUT_TOKEN {
+			if let Some(engine) = self.engine.upgrade() {
+				engine.step.fetch_add(1, AtomicOrdering::Relaxed);
+				io.register_timer_once(ENGINE_TIMEOUT_TOKEN, engine.our_params.step_duration).expect("Failed to restart consensus step timer.")
+			}
+		}
+	}
+
+	fn message(&self, io: &IoContext<BlockArrived>, _net_message: &BlockArrived) {
+		if let Some(engine) = self.engine.upgrade() {
+			println!("Message: {:?}", get_time().sec);
+			engine.step.fetch_add(1, AtomicOrdering::Relaxed);
+			io.clear_timer(ENGINE_TIMEOUT_TOKEN).expect("Failed to restart consensus step timer.");
+			io.register_timer_once(ENGINE_TIMEOUT_TOKEN, engine.our_params.step_duration).expect("Failed to restart consensus step timer.")
+		}
+	}
+}
+
+impl Engine for AuthorityRound {
+	fn name(&self) -> &str { "AuthorityRound" }
+	fn version(&self) -> SemanticVersion { SemanticVersion::new(1, 0, 0) }
+	// One field - the proposer signature.
+	fn seal_fields(&self) -> usize { 1 }
+
+	fn params(&self) -> &CommonParams { &self.params }
+	fn builtins(&self) -> &BTreeMap<Address, Builtin> { &self.builtins }
+
+	/// Additional engine-specific information for the user/developer concerning `header`.
+	fn extra_info(&self, _header: &Header) -> HashMap<String, String> { hash_map!["signature".to_owned() => "TODO".to_owned()] }
+
+	fn schedule(&self, _env_info: &EnvInfo) -> Schedule {
+		Schedule::new_homestead()
+	}
+
+	fn populate_from_parent(&self, header: &mut Header, parent: &Header, gas_floor_target: U256, _gas_ceil_target: U256) {
+		header.set_difficulty(parent.difficulty().clone());
+		header.set_gas_limit({
+			let gas_limit = parent.gas_limit().clone();
+			let bound_divisor = self.our_params.gas_limit_bound_divisor;
+			if gas_limit < gas_floor_target {
+				min(gas_floor_target, gas_limit + gas_limit / bound_divisor - 1.into())
+			} else {
+				max(gas_floor_target, gas_limit - gas_limit / bound_divisor + 1.into())
+			}
+		});
+	}
+
+	/// Apply the block reward on finalisation of the block.
+	/// This assumes that all uncles are valid uncles (i.e. of at least one generation before the current).
+	fn on_close_block(&self, _block: &mut ExecutedBlock) {}
+
+	/// Attempt to seal the block internally.
+	///
+	/// This operation is synchronous and may (quite reasonably) not be available, in which `false` will
+	/// be returned.
+	fn generate_seal(&self, block: &ExecutedBlock, accounts: Option<&AccountProvider>) -> Option<Vec<Bytes>> {
+		if self.is_proposer(block.header().author()) {
+			if let Some(ap) = accounts {
+				let header = block.header();
+				let message = header.bare_hash();
+				// Account should be pernamently unlocked, otherwise sealing will fail.
+				if let Ok(signature) = ap.sign(*header.author(), message) {
+					return Some(vec![encode(&(&*signature as &[u8])).to_vec()]);
+				} else {
+					trace!(target: "authorityround", "generate_seal: FAIL: accounts secret key unavailable");
+				}
+			} else {
+				trace!(target: "authorityround", "generate_seal: FAIL: accounts not provided");
+			}
+		}
+		None
+	}
+
+	/// Check the number of seal fields.
+	fn verify_block_basic(&self, header: &Header, _block: Option<&[u8]>) -> result::Result<(), Error> {
+		if header.seal().len() != self.seal_fields() {
+			return Err(From::from(BlockError::InvalidSealArity(
+				Mismatch { expected: self.seal_fields(), found: header.seal().len() }
+			)));
+		}
+		Ok(())
+	}
+
+	/// Check if the signature belongs to the correct proposer.
+	fn verify_block_unordered(&self, header: &Header, _block: Option<&[u8]>) -> result::Result<(), Error> {
+		let sig = try!(UntrustedRlp::new(&header.seal()[0]).as_val::<H520>());
+		let signer = public_to_address(&try!(recover(&sig.into(), &header.bare_hash())));
+		if self.is_proposer(&signer) {
+			Ok(())
+		} else {
+			try!(Err(BlockError::InvalidSeal))
+		}
+	}
+
+	fn verify_block_family(&self, header: &Header, parent: &Header, _block: Option<&[u8]>) -> result::Result<(), Error> {
+		// Don't calculate difficulty for genesis blocks.
+		if header.number() == 0 {
+			return Err(From::from(BlockError::RidiculousNumber(OutOfBounds { min: Some(1), max: None, found: header.number() })));
+		}
+
+		// Check difficulty is correct given the two timestamps.
+		if header.difficulty() != parent.difficulty() {
+			return Err(From::from(BlockError::InvalidDifficulty(Mismatch { expected: *parent.difficulty(), found: *header.difficulty() })))
+		}
+		let gas_limit_divisor = self.our_params.gas_limit_bound_divisor;
+		let min_gas = parent.gas_limit().clone() - parent.gas_limit().clone() / gas_limit_divisor;
+		let max_gas = parent.gas_limit().clone() + parent.gas_limit().clone() / gas_limit_divisor;
+		if header.gas_limit() <= &min_gas || header.gas_limit() >= &max_gas {
+			return Err(From::from(BlockError::InvalidGasLimit(OutOfBounds { min: Some(min_gas), max: Some(max_gas), found: header.gas_limit().clone() })));
+		}
+		Ok(())
+	}
+
+	fn verify_transaction_basic(&self, t: &SignedTransaction, _header: &Header) -> result::Result<(), Error> {
+		try!(t.check_low_s());
+		Ok(())
+	}
+
+	fn verify_transaction(&self, t: &SignedTransaction, _header: &Header) -> Result<(), Error> {
+		t.sender().map(|_|()) // Perform EC recovery and cache sender
+	}
+}
+
+impl Header {
+	/// Get the none field of the header.
+	pub fn signature(&self) -> H520 {
+		decode(&self.seal()[0])
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use common::*;
+	use rlp::{UntrustedRlp, View, encode, decode};
+	use block::*;
+	use tests::helpers::*;
+	use account_provider::AccountProvider;
+	use spec::Spec;
+
+	/// Create a new test chain spec with `AuthorityRound` consensus engine.
+	fn new_test_authority() -> Spec {
+		let bytes: &[u8] = include_bytes!("../../res/authority_round.json");
+		Spec::load(bytes).expect("invalid chain spec")
+	}
+
+	#[test]
+	fn has_valid_metadata() {
+		let engine = new_test_authority().engine;
+		assert!(!engine.name().is_empty());
+		assert!(engine.version().major >= 1);
+	}
+
+	#[test]
+	fn can_return_schedule() {
+		let engine = new_test_authority().engine;
+		let schedule = engine.schedule(&EnvInfo {
+			number: 10000000,
+			author: 0.into(),
+			timestamp: 0,
+			difficulty: 0.into(),
+			last_hashes: Arc::new(vec![]),
+			gas_used: 0.into(),
+			gas_limit: 0.into(),
+		});
+
+		assert!(schedule.stack_limit > 0);
+	}
+
+	#[test]
+	fn can_do_seal_verification_fail() {
+		let engine = new_test_authority().engine;
+		let header: Header = Header::default();
+
+		let verify_result = engine.verify_block_basic(&header, None);
+
+		match verify_result {
+			Err(Error::Block(BlockError::InvalidSealArity(_))) => {},
+			Err(_) => { panic!("should be block seal-arity mismatch error (got {:?})", verify_result); },
+			_ => { panic!("Should be error, got Ok"); },
+		}
+	}
+
+	#[test]
+	fn can_do_signature_verification_fail() {
+		let engine = new_test_authority().engine;
+		let mut header: Header = Header::default();
+		header.set_seal(vec![encode(&H520::default()).to_vec()]);
+
+		let verify_result = engine.verify_block_unordered(&header, None);
+		assert!(verify_result.is_err());
+	}
+
+	#[test]
+	fn can_generate_seal() {
+		let tap = AccountProvider::transient_provider();
+		let addr = tap.insert_account("".sha3(), "").unwrap();
+		tap.unlock_account_permanently(addr, "".into()).unwrap();
+
+		let spec = new_test_authority();
+		let engine = &*spec.engine;
+		let genesis_header = spec.genesis_header();
+		let mut db_result = get_temp_journal_db();
+		let mut db = db_result.take();
+		spec.ensure_db_good(db.as_hashdb_mut()).unwrap();
+		let last_hashes = Arc::new(vec![genesis_header.hash()]);
+		let b = OpenBlock::new(engine, Default::default(), false, db, &genesis_header, last_hashes, addr, (3141562.into(), 31415620.into()), vec![]).unwrap();
+		let b = b.close_and_lock();
+		let seal = engine.generate_seal(b.block(), Some(&tap)).unwrap();
+		assert!(b.try_seal(engine, seal).is_ok());
+	}
+}

ethcore/src/engines/mod.rs

@@ -19,10 +19,12 @@
 mod null_engine;
 mod instant_seal;
 mod basic_authority;
+mod authority_round;
 
 pub use self::null_engine::NullEngine;
 pub use self::instant_seal::InstantSeal;
 pub use self::basic_authority::BasicAuthority;
+pub use self::authority_round::AuthorityRound;
 
 use common::*;
 use account_provider::AccountProvider;