From 8da38fa98b8c88fee4242e988f405b7657d49d77 Mon Sep 17 00:00:00 2001 From: keorn Date: Fri, 19 Aug 2016 17:18:30 +0200 Subject: [PATCH] intro simple seal bft engine --- ethcore/res/bft.json | 39 +++++ ethcore/src/engines/bft.rs | 289 +++++++++++++++++++++++++++++++++++++ ethcore/src/engines/mod.rs | 4 + 3 files changed, 332 insertions(+) create mode 100644 ethcore/res/bft.json create mode 100644 ethcore/src/engines/bft.rs diff --git a/ethcore/res/bft.json b/ethcore/res/bft.json new file mode 100644 index 000000000..24bd386b2 --- /dev/null +++ b/ethcore/res/bft.json @@ -0,0 +1,39 @@ +{ + "name": "TestBFT", + "engine": { + "BFT": { + "params": { + "gasLimitBoundDivisor": "0x0400", + "durationLimit": "0x0d", + "validators" : ["0x9cce34f7ab185c7aba1b7c8140d620b4bda941d6"] + } + } + }, + "params": { + "accountStartNonce": "0x0100000", + "maximumExtraDataSize": "0x20", + "minGasLimit": "0x1388", + "networkID" : "0x69" + }, + "genesis": { + "seal": { + "generic": { + "fields": 1, + "rlp": "0x11bbe8db4e347b4e8c937c1c8370e4b5ed33adb3db69cbdb7a38e1e50b1b82fa" + } + }, + "difficulty": "0x20000", + "author": "0x0000000000000000000000000000000000000000", + "timestamp": "0x00", + "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000", + "extraData": "0x", + "gasLimit": "0x2fefd8" + }, + "accounts": { + "0000000000000000000000000000000000000001": { "balance": "1", "nonce": "1048576", "builtin": { "name": "ecrecover", "pricing": { "linear": { "base": 3000, "word": 0 } } } }, + "0000000000000000000000000000000000000002": { "balance": "1", "nonce": "1048576", "builtin": { "name": "sha256", "pricing": { "linear": { "base": 60, "word": 12 } } } }, + "0000000000000000000000000000000000000003": { "balance": "1", "nonce": "1048576", "builtin": { "name": "ripemd160", "pricing": { "linear": { "base": 600, "word": 120 } } } }, + "0000000000000000000000000000000000000004": { "balance": "1", "nonce": "1048576", "builtin": { "name": "identity", "pricing": { "linear": { "base": 15, "word": 3 } } } }, + "9cce34f7ab185c7aba1b7c8140d620b4bda941d6": { "balance": "1606938044258990275541962092341162602522202993782792835301376", "nonce": "1048576" } + } +} diff --git a/ethcore/src/engines/bft.rs b/ethcore/src/engines/bft.rs new file mode 100644 index 000000000..aae6854d2 --- /dev/null +++ b/ethcore/src/engines/bft.rs @@ -0,0 +1,289 @@ +// 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 . + +//! A blockchain engine that supports a basic, non-BFT proof-of-authority. + +use common::*; +use account_provider::AccountProvider; +use block::*; +use spec::CommonParams; +use engines::Engine; +use evm::Schedule; +use ethjson; + +/// `BFT` params. +#[derive(Debug, PartialEq)] +pub struct BFTParams { + /// Gas limit divisor. + pub gas_limit_bound_divisor: U256, + /// Block duration. + pub duration_limit: u64, + /// Validators. + pub validators: Vec
, + /// Number of validators. + pub validator_n: usize, + /// Precommit step votes. + precommits: HashMap> +} + +impl From for BFTParams { + fn from(p: ethjson::spec::BFTParams) -> Self { + let val = p.validators.into_iter().map(Into::into).collect::>(); + BFTParams { + gas_limit_bound_divisor: p.gas_limit_bound_divisor.into(), + duration_limit: p.duration_limit.into(), + validators: auth, + validator_n: val.len() + } + } +} + +/// Engine using `BFT` consensus algorithm, suitable for EVM chain. +pub struct BFT { + params: CommonParams, + our_params: BFTParams, + builtins: BTreeMap, +} + +impl BFT { + /// Create a new instance of BFT engine + pub fn new(params: CommonParams, our_params: BFTParams, builtins: BTreeMap) -> Self { + BFT { + params: params, + our_params: our_params, + builtins: builtins, + } + } + + fn check_precommit(&self, bare_hash: &H256, signature: &H520) -> result::Result<(), Error> { + let signer = Address::from(try!(ec::recover(&sig, bare_hash)).sha3()); + if !self.our_params.validators.contains(&signer) { + return try!(Err(BlockError::InvalidSeal)); + } + Ok(()) + } + + fn supermajority(&self) -> usize { 2*self.our_params.validator_n/3 } + + fn signatures_seal(&self, signatures: &HashSet) -> Vec { + signatures.iter().map(|sig| encode(&(&*sig as &[u8])).to_vec()).collect() + } +} + +impl Engine for BFT { + fn name(&self) -> &str { "BFT" } + fn version(&self) -> SemanticVersion { SemanticVersion::new(1, 0, 0) } + /// Possibly signatures of all validators. + fn seal_fields(&self) -> usize { self.our_params.validator_n } + + fn params(&self) -> &CommonParams { &self.params } + fn builtins(&self) -> &BTreeMap { &self.builtins } + + /// Additional engine-specific information for the user/developer concerning `header`. + fn extra_info(&self, _header: &Header) -> HashMap { 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.difficulty = parent.difficulty; + header.gas_limit = { + let gas_limit = parent.gas_limit; + 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()) + } + }; + header.note_dirty(); + } + + /// 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 using all available signatures. + /// + /// None is returned if not enough signatures can be collected. + fn generate_seal(&self, block: &ExecutedBlock, accounts: Option<&AccountProvider>) -> Option> { + let hash = block.bare_hash(); + let signatures = self.our_params.precommits.entry(hash).or_insert(HashSet::new()); + let threshold = self.supermajority(); + match (signatures.len(), accounts) { + (threshold-1, Some(ap)) => { + // account should be pernamently unlocked, otherwise signing will fail + if let Ok(signature) = ap.sign(*block.header().author(), hash) { + *signatures.insert(signature); + Some(self.signatures_seal(signatures)); + } else { + trace!(target: "bft", "generate_seal: FAIL: secret key unavailable"); + None + } + }, + (0..threshold, _) => None, + (threshold.., _) => Some(block.header().seal), + } + } + + fn verify_block_basic(&self, header: &Header, _block: Option<&[u8]>) -> result::Result<(), Error> { + // check the seal fields. + // TODO: pull this out into common code. + if header.seal.len() != self.seal_fields() { + return Err(From::from(BlockError::InvalidSealArity( + Mismatch { expected: self.seal_fields(), found: header.seal.len() } + ))); + } + Ok(()) + } + + fn verify_block_unordered(&self, header: &Header, _block: Option<&[u8]>) -> result::Result<(), Error> { + let hash = header.bare_hash(); + let threshold = self.supermajority(); + let signatures = self.our_params.precommits.entry(hash).or_insert(HashSet::new()); + if signatures.len() > threshold { return Ok(()) } + // Count all valid precommits. + for seal_field in header.seal { + let sig = try!(UntrustedRlp::new(seal_field).as_val::()); + if !signatures.contains(sig) || self.check_precommit(hash, sig).is_ok() { + trace!(target: "bft", "verify_block_unordered: new validator vote found"); + *signatures.insert(sig); + if signatures.len() > threshold { return Ok(()) } + } + } + Err(BlockError::InvalidSeal) + } + + fn verify_block_family(&self, header: &Header, parent: &Header, _block: Option<&[u8]>) -> result::Result<(), Error> { + // we should not 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 - parent.gas_limit / gas_limit_divisor; + let max_gas = parent.gas_limit + parent.gas_limit / 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 }))); + } + 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 block::*; + use tests::helpers::*; + use account_provider::AccountProvider; + use spec::Spec; + + /// Create a new test chain spec with `BFT` consensus engine. + fn new_test_authority() -> Spec { Spec::load(include_bytes!("../../res/test_authority.json")) } + + #[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![rlp::encode(&Signature::zero()).to_vec()]); + + let verify_result = engine.verify_block_unordered(&header, None); + + match verify_result { + Err(Error::Util(UtilError::Crypto(CryptoError::InvalidSignature))) => {}, + Err(_) => { panic!("should be block difficulty error (got {:?})", verify_result); }, + _ => { panic!("Should be error, got Ok"); }, + } + } + + #[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 vm_factory = Default::default(); + let b = OpenBlock::new(engine, &vm_factory, 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()); + } +} diff --git a/ethcore/src/engines/mod.rs b/ethcore/src/engines/mod.rs index e7738fbaa..2f3c0d189 100644 --- a/ethcore/src/engines/mod.rs +++ b/ethcore/src/engines/mod.rs @@ -113,6 +113,10 @@ pub trait Engine : Sync + Send { header.note_dirty(); } + /// Handle any potential consensus messages; + /// updating consensus state and potentially issuing a new one. + fn handle_message(&self, sender: Address, message: Bytes) -> Option> { None } + // TODO: builtin contract routing - to do this properly, it will require removing the built-in configuration-reading logic // from Spec into here and removing the Spec::builtins field. /// Determine whether a particular address is a builtin contract.