BABE signing and verification (#2270)

* Add basic BABE consensus type * Update core/consensus/babe/slots/Cargo.toml Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com> * Fix parameterization and run `rustfmt` * Respond to review comments * Update various Cargo.lock files * Revert "Update various Cargo.lock files" This reverts commit af53d7624752a744320e9cbb25749fdd8e6f46d2. * `BabeSealSignature` → `BabeSeal` * Move slot code to its own crate This was highly non-trivial, due to cyclic dependencies. * Remove redundancy between AuRa and BABE Some of the code duplication was removed using a macro. * Fix build error * Avoid non-`#[doc(hidden)]` re-exports Also, bump some library versions in `Cargo.toml`. * Remove dead code in AuRa * Remove impl_slot macro It was more trouble than it was worth. Also, delete useless dependencies on Serde. * AuRa and BABE need different DB keys * Bring back `aura::Network`, but deprecate it. * Improve docs and add `slot_duration` inherent method * Add docs to `substrate_consensus_aura::SlotDuration` * Add missing documentation and #![forbid(missing_docs, unsafe_code)] * Add a #![forbid(missing_docs)] * Remove dependency of `test-runtime` on `slots` * Update core/consensus/babe/src/lib.rs Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com> * Remove wrongly added file * Fix copyright notice Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com> * Bump `impl_version` and `spec_version` * Add more code to BABE Most of it is copied from AuRa code, but at least the initial core is there. * Stuck on horrible compiler error message * add missing files * Spaces → tabs * Simplify code * Fix compilation This involved fixing dependencies and adding a `Mutex`. * More work on BABE * Fix deprecation version * Fix deprecation version; remove spurious carets * Fix Cargo.toml * Implement VRF signing logic * The import queue code compiles, though it probably doesn’t work. * Add VRF verification * Update Cargo.lock * Update dependencies * Move test network to sr25519 authority keys * Fix accidental build bustage * Trying to get the tests to work * Add logging messages and remove dead code There seems to be a problem with the test network. Since AuRa and BABE are both affected, this is most likely due to the switch from ed25519 to sr25519. * Trying to get the tests to work * Add logging messages and remove dead code There seems to be a problem with the test network. Since AuRa and BABE are both affected, this is most likely due to the switch from ed25519 to sr25519. * Working testsuite at last! The problem was with serialization and deserialization. Normally, those functions are generated automatically, but those for `BabeSeal` had to be written manually. The hand-written versions were not correct, however, as shown by the decoder not being able to decode the output of the encoder. * Enable BabeSeal::Encode asserts in --release tests * Bump runtime and dependency versions * Fix wasm compilation The wasm build was broken because of a typo in `core/test-runtime/src/lib.rs`, and missing gates on the `std` feature in `core/consensus/{aura,babe}/primitives/Cargo.toml`. Additionally, improve the quotation in the build scripts. * Merge Cargo.lock * Change expected JSON string The test was also broken on `master`, so I suspect that the test was incorrect. * Responded to review * Remove hard-coded threshold from production code A hard-coded threshold is now only used in tests. * Fix swapped doc comments * Fix unused import warnings * fix ci error * fix typo * Fix spacing in docs * Minor changes suggested by @joepetrowski on https://github.com/paritytech/substrate/pull/2372 * Remove unnecessary getters * fix compile error * Fix silly unused-variable error * Improve documentation formatting Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com> * Add issue links * Revert excess verbosity and #![forbid(warnings)] * Apply suggestions from code review Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com> * Reformat some comments * Threshold should depend on number of validators Also, respond to code review * Fix silly compilation errors * Reduce logging verbosity * Fix missing import
2026-05-30 23:21:02 +00:00 · 2019-05-02 11:16:54 -04:00
parent d3f59a0712
commit fb19684358
40 changed files with 1570 additions and 263 deletions
@@ -2892,23 +2892,6 @@ dependencies = [
 "winapi 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

-[[package]]
-name = "schnorrkel"
-version = "0.1.1"
-source = "git+https://github.com/paritytech/schnorrkel#1762df02ac48ba5c3fa8c162e19a393247079f88"
-dependencies = [
- "clear_on_drop 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "curve25519-dalek 1.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "ed25519-dalek 1.0.0-pre.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "merlin 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "sha2 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "sha3 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "subtle 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "schnorrkel"
 version = "0.1.1"
@@ -3271,6 +3254,29 @@ dependencies = [
 "substrate-primitives 1.0.0",
 ]

+[[package]]
+name = "srml-babe"
+version = "0.1.0"
+dependencies = [
+ "hex-literal 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-codec 3.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.90 (registry+https://github.com/rust-lang/crates.io-index)",
+ "sr-io 1.0.0",
+ "sr-primitives 1.0.0",
+ "sr-std 1.0.0",
+ "srml-consensus 1.0.0",
+ "srml-session 1.0.0",
+ "srml-staking 1.0.0",
+ "srml-support 1.0.0",
+ "srml-system 1.0.0",
+ "srml-timestamp 1.0.0",
+ "substrate-consensus-babe-primitives 1.0.0",
+ "substrate-inherents 1.0.0",
+ "substrate-primitives 1.0.0",
+]
+
 [[package]]
 name = "srml-balances"
 version = "1.0.0"
@@ -3936,13 +3942,16 @@ dependencies = [
 "error-chain 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "futures 0.1.26 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "merlin 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "parity-codec 3.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "parity-codec-derive 3.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "schnorrkel 0.1.1 (git+https://github.com/paritytech/schnorrkel)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "schnorrkel 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "sr-io 1.0.0",
 "sr-primitives 1.0.0",
 "sr-version 1.0.0",
+ "srml-babe 0.1.0",
 "srml-consensus 1.0.0",
 "srml-support 1.0.0",
 "substrate-client 1.0.0",
@@ -4450,6 +4459,7 @@ dependencies = [
 "substrate-client 1.0.0",
 "substrate-consensus-aura-primitives 1.0.0",
 "substrate-consensus-authorities 1.0.0",
+ "substrate-consensus-babe-primitives 1.0.0",
 "substrate-executor 1.0.0",
 "substrate-inherents 1.0.0",
 "substrate-keyring 1.0.0",
@@ -5671,7 +5681,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum safemem 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8dca453248a96cb0749e36ccdfe2b0b4e54a61bfef89fb97ec621eb8e0a93dd9"
 "checksum same-file 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "8f20c4be53a8a1ff4c1f1b2bd14570d2f634628709752f0702ecdd2b3f9a5267"
 "checksum schannel 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)" = "f2f6abf258d99c3c1c5c2131d99d064e94b7b3dd5f416483057f308fea253339"
-"checksum schnorrkel 0.1.1 (git+https://github.com/paritytech/schnorrkel)" = "<none>"
 "checksum schnorrkel 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b5eff518f9bed3d803a0d002af0ab96339b0ebbedde3bec98a684986134b7a39"
 "checksum scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "94258f53601af11e6a49f722422f6e3425c52b06245a5cf9bc09908b174f5e27"
 "checksum secp256k1 0.12.2 (registry+https://github.com/rust-lang/crates.io-index)" = "bfaccd3a23619349e0878d9a241f34b1982343cdf67367058cd7d078d326b63e"
@@ -12,5 +12,6 @@ runtime_primitives = { package = "sr-primitives", path = "../../../sr-primitives
 [features]
 default = ["std"]
 std = [
+	"runtime_primitives/std",
 	"substrate-client/std",
 ]
@@ -62,10 +62,10 @@ use srml_aura::{
 };
 use substrate_telemetry::{telemetry, CONSENSUS_TRACE, CONSENSUS_DEBUG, CONSENSUS_WARN, CONSENSUS_INFO};

-use slots::{CheckedHeader, SlotWorker, SlotInfo, SlotCompatible};
+use slots::{CheckedHeader, SlotWorker, SlotInfo, SlotCompatible, slot_now};

 pub use aura_primitives::*;
-pub use consensus_common::SyncOracle;
+pub use consensus_common::{SyncOracle, ExtraVerification};

 type AuthorityId<P> = <P as Pair>::Public;
 type Signature<P> = <P as Pair>::Signature;
@@ -120,20 +120,6 @@ fn slot_author<P: Pair>(slot_num: u64, authorities: &[AuthorityId<P>]) -> Option
 	Some(current_author)
 }

-fn duration_now() -> Option<Duration> {
-	use std::time::SystemTime;
-
-	let now = SystemTime::now();
-	now.duration_since(SystemTime::UNIX_EPOCH).map_err(|e| {
-			warn!("Current time {:?} is before unix epoch. Something is wrong: {:?}", now, e);
-	}).ok()
-}
-
-/// Get the slot for now.
-fn slot_now(slot_duration: u64) -> Option<u64> {
-	duration_now().map(|s| s.as_secs() / slot_duration)
-}
-
 fn inherent_to_common_error(err: RuntimeString) -> consensus_common::Error {
 	consensus_common::ErrorKind::InherentData(err.into()).into()
 }
@@ -467,7 +453,6 @@ impl<B: Block, C, E, I, P, Error, SO> SlotWorker<B> for AuraWorker<C, E, I, P, S
 /// This digest item will always return `Some` when used with `as_aura_seal`.
 //
 // FIXME #1018 needs misbehavior types
-#[forbid(deprecated)]
 fn check_header<B: Block, P: Pair>(
 	slot_now: u64,
 	mut header: B::Header,
@@ -517,19 +502,6 @@ fn check_header<B: Block, P: Pair>(
 	}
 }

-/// Extra verification for Aura blocks.
-pub trait ExtraVerification<B: Block>: Send + Sync {
-	/// Future that resolves when the block is verified or fails with error if not.
-	type Verified: IntoFuture<Item=(),Error=String>;
-
-	/// Do additional verification for this block.
-	fn verify(
-		&self,
-		header: &B::Header,
-		body: Option<&[B::Extrinsic]>,
-	) -> Self::Verified;
-}
-
 /// A verifier for Aura blocks.
 pub struct AuraVerifier<C, E, P> {
 	client: Arc<C>,
@@ -785,7 +757,8 @@ pub fn import_queue<B, C, E, P>(

 /// Start an import queue for the Aura consensus algorithm with backwards compatibility.
 #[deprecated(
-	note = "should not be used unless backwards compatibility with an older chain is needed."
+	since = "1.0.1",
+	note = "should not be used unless backwards compatibility with an older chain is needed.",
 )]
 pub fn import_queue_accept_old_seals<B, C, E, P>(
 	slot_duration: SlotDuration,
@@ -828,8 +801,8 @@ mod tests {
 	use network::config::ProtocolConfig;
 	use parking_lot::Mutex;
 	use tokio::runtime::current_thread;
-	use keyring::ed25519::Keyring;
-	use primitives::ed25519;
+	use keyring::sr25519::Keyring;
+	use primitives::sr25519;
 	use client::BlockchainEvents;
 	use test_client;

@@ -844,7 +817,7 @@ mod tests {
 		type Proposer = DummyProposer;
 		type Error = Error;

-		fn init(&self, parent_header: &<TestBlock as BlockT>::Header, _authorities: &[AuthorityId<ed25519::Pair>])
+		fn init(&self, parent_header: &<TestBlock as BlockT>::Header, _authorities: &[AuthorityId<sr25519::Pair>])
 			-> Result<DummyProposer, Error>
 		{
 			Ok(DummyProposer(parent_header.number + 1, self.0.clone()))
@@ -870,7 +843,7 @@ mod tests {

 	impl TestNetFactory for AuraTestNet {
 		type Specialization = DummySpecialization;
-		type Verifier = AuraVerifier<PeersClient, NothingExtra, ed25519::Pair>;
+		type Verifier = AuraVerifier<PeersClient, NothingExtra, sr25519::Pair>;
 		type PeerData = ();

 		/// Create new test network with peers and given config.
@@ -957,7 +930,7 @@ mod tests {
 				&inherent_data_providers, slot_duration.get()
 			).expect("Registers aura inherent data provider");

-			let aura = start_aura::<_, _, _, _, ed25519::Pair, _, _, _>(
+			let aura = start_aura::<_, _, _, _, sr25519::Pair, _, _, _>(
 				slot_duration,
 				Arc::new(key.clone().into()),
 				client.clone(),
@@ -16,6 +16,7 @@ runtime_io = { package = "sr-io", path = "../../sr-io" }
 inherents = { package = "substrate-inherents", path = "../../inherents" }
 srml-consensus = { path = "../../../srml/consensus" }
 substrate-telemetry = { path = "../../telemetry" }
+srml-babe = { path = "../../../srml/babe" }
 client = { package = "substrate-client", path = "../../client" }
 consensus_common = { package = "substrate-consensus-common", path = "../common" }
 authorities = { package = "substrate-consensus-authorities", path = "../authorities" }
@@ -26,10 +27,9 @@ tokio = "0.1.18"
 parking_lot = "0.7.1"
 error-chain = "0.12.0"
 log = "0.4.6"
-
-[dependencies.schnorrkel]
-git = "https://github.com/paritytech/schnorrkel"
-branch = "master"
+schnorrkel = "0.1.1"
+rand = "0.6.5"
+merlin = "1.0.3"

 [dev-dependencies]
 keyring = { package = "substrate-keyring", path = "../../keyring" }
@@ -9,11 +9,13 @@ edition = "2018"
 substrate-client = { path = "../../../client", default-features = false }
 runtime_primitives = { package = "sr-primitives", path = "../../../sr-primitives", default-features = false }
 slots = { package = "substrate-consensus-slots", path = "../../slots", optional = true }
-parity-codec = "^3.4.0"
+parity-codec = { version = "3.5.1", default-features = false }

 [features]
 default = ["std"]
 std = [
+	"runtime_primitives/std",
 	"substrate-client/std",
+	"parity-codec/std",
 	"slots",
 ]
@@ -29,31 +29,28 @@ pub const BABE_ENGINE_ID: ConsensusEngineId = [b'b', b'a', b'b', b'e'];
 /// Configuration data used by the BABE consensus engine.
 #[derive(Copy, Clone, Hash, PartialEq, Eq, Debug, Encode, Decode)]
 pub struct BabeConfiguration {
-	slot_duration: u64,
-	expected_block_time: u64,
-}
-
-impl BabeConfiguration {
-	/// Return the expected block time in milliseconds for BABE.  Currently,
-	/// only the value provided by this type at genesis will be used.
-	///
-	/// Dynamic expected block time may be supported in the future.
-	pub fn expected_block_time(&self) -> u64 {
-		self.expected_block_time
-	}
-
-	/// Return the slot duration in milliseconds for BABE.  Currently, only
+	/// The slot duration in milliseconds for BABE. Currently, only
 	/// the value provided by this type at genesis will be used.
 	///
 	/// Dynamic slot duration may be supported in the future.
-	pub fn slot_duration(&self) -> u64 {
-		self.slot_duration
-	}
+	pub slot_duration: u64,
+
+	/// The expected block time in milliseconds for BABE. Currently,
+	/// only the value provided by this type at genesis will be used.
+	///
+	/// Dynamic expected block time may be supported in the future.
+	pub expected_block_time: u64,
+
+	/// The maximum permitted VRF output, or *threshold*, for BABE. Currently,
+	/// only the value provided by this type at genesis will be used.
+	///
+	/// Dynamic thresholds may be supported in the future.
+	pub threshold: u64,
 }

 #[cfg(feature = "std")]
 impl slots::SlotData for BabeConfiguration {
-	/// Return the slot duration in milliseconds for BABE.  Currently, only
+	/// Return the slot duration in milliseconds for BABE. Currently, only
 	/// the value provided by this type at genesis will be used.
 	///
 	/// Dynamic slot duration may be supported in the future.
@@ -67,7 +64,7 @@ impl slots::SlotData for BabeConfiguration {
 decl_runtime_apis! {
 	/// API necessary for block authorship with BABE.
 	pub trait BabeApi {
-		/// Return the configuration for BABE.  Currently,
+		/// Return the configuration for BABE. Currently,
 		/// only the value provided by this type at genesis will be used.
 		///
 		/// Dynamic configuration may be supported in the future.
@@ -17,12 +17,13 @@
 //! Import Queue primitive: something which can verify and import blocks.
 //!
 //! This serves as an intermediate and abstracted step between synchronization
-//! and import. Each mode of consensus will have its own requirements for block verification.
-//! Some algorithms can verify in parallel, while others only sequentially.
+//! and import. Each mode of consensus will have its own requirements for block
+//! verification. Some algorithms can verify in parallel, while others only
+//! sequentially.
 //!
-//! The `ImportQueue` trait allows such verification strategies to be instantiated.
-//! The `BasicQueue` and `BasicVerifier` traits allow serial queues to be
-//! instantiated simply.
+//! The `ImportQueue` trait allows such verification strategies to be
+//! instantiated. The `BasicQueue` and `BasicVerifier` traits allow serial
+//! queues to be instantiated simply.

 use crate::block_import::{
 	BlockImport, BlockOrigin, ImportBlock, ImportedAux, ImportResult, JustificationImport,
@@ -106,8 +107,8 @@ impl<B: BlockT> Clone for Box<ImportQueue<B>> {
 	}
 }

-/// Interface to a basic block import queue that is importing blocks sequentially in a separate thread,
-/// with pluggable verification.
+/// Interface to a basic block import queue that is importing blocks
+/// sequentially in a separate thread, with pluggable verification.
 #[derive(Clone)]
 pub struct BasicQueue<B: BlockT> {
 	sender: Sender<BlockImportMsg<B>>,
@@ -120,20 +121,24 @@ impl<B: BlockT> ImportQueueClone<B> for BasicQueue<B> {
 }

 /// "BasicQueue" is a wrapper around a channel sender to the "BlockImporter".
-/// "BasicQueue" itself does not keep any state or do any importing work, and can therefore be send to other threads.
+/// "BasicQueue" itself does not keep any state or do any importing work, and
+/// can therefore be send to other threads.
 ///
-/// "BasicQueue" implements "ImportQueue" by sending messages to the "BlockImporter", which runs in it's own thread.
+/// "BasicQueue" implements "ImportQueue" by sending messages to the
+/// "BlockImporter", which runs in it's own thread.
 ///
-/// The "BlockImporter" is responsible for handling incoming requests from the "BasicQueue",
-/// some of these requests are handled by the "BlockImporter" itself, such as "is_importing" or "status",
-/// and justifications are also imported by the "BlockImporter".
+/// The "BlockImporter" is responsible for handling incoming requests from the
+/// "BasicQueue". Some of these requests are handled by the "BlockImporter"
+/// itself, such as "is_importing", "status", and justifications.
 ///
-/// The "import block" work will be offloaded to a single "BlockImportWorker", running in another thread.
-/// Offloading the work is done via a channel,
-/// ensuring blocks in this implementation are imported sequentially and in order(as received by the "BlockImporter")
+/// The "import block" work will be offloaded to a single "BlockImportWorker",
+/// running in another thread. Offloading the work is done via a channel,
+/// ensuring blocks in this implementation are imported sequentially and in
+/// order (as received by the "BlockImporter").
 ///
-/// As long as the "BasicQueue" is not dropped, the "BlockImporter" will keep running.
-/// The "BlockImporter" owns a sender to the "BlockImportWorker", ensuring that the worker is kept alive until that sender is dropped.
+/// As long as the "BasicQueue" is not dropped, the "BlockImporter" will keep
+/// running. The "BlockImporter" owns a sender to the "BlockImportWorker",
+/// ensuring that the worker is kept alive until that sender is dropped.
 impl<B: BlockT> BasicQueue<B> {
 	/// Instantiate a new basic queue, with given verifier.
 	pub fn new<V: 'static + Verifier<B>>(
@@ -152,8 +157,8 @@ impl<B: BlockT> BasicQueue<B> {

 	/// Send synchronization request to the block import channel.
 	///
-	/// The caller should wait for Link::synchronized() call to ensure that it has synchronized
-	/// with ImportQueue.
+	/// The caller should wait for Link::synchronized() call to ensure that it
+	/// has synchronized with ImportQueue.
 	#[cfg(any(test, feature = "test-helpers"))]
 	pub fn synchronize(&self) {
 		self
@@ -238,6 +243,7 @@ impl<B: BlockT> BlockImporter<B> {
 		worker_sender: Sender<BlockImportWorkerMsg<B>>,
 		justification_import: Option<SharedJustificationImport<B>>,
 	) -> Sender<BlockImportMsg<B>> {
+		trace!(target: "block_import", "Creating new Block Importer!");
 		let (sender, port) = channel::bounded(4);
 		let _ = thread::Builder::new()
 			.name("ImportQueue".into())
@@ -258,6 +264,7 @@ impl<B: BlockT> BlockImporter<B> {
 	}

 	fn run(&mut self) -> bool {
+		trace!(target: "import_queue", "Running import queue");
 		let msg = select! {
 			recv(self.port) -> msg => {
 				match msg {
@@ -297,6 +304,7 @@ impl<B: BlockT> BlockImporter<B> {
 			BlockImportMsg::Stop => return false,
 			#[cfg(any(test, feature = "test-helpers"))]
 			BlockImportMsg::Synchronize => {
+				trace!(target: "sync", "Received synchronization message");
 				self.worker_sender
 					.send(BlockImportWorkerMsg::Synchronize)
 					.expect("1. This is holding a sender to the worker, 2. the worker should not quit while a sender is still held; qed");
@@ -318,6 +326,7 @@ impl<B: BlockT> BlockImporter<B> {
 			BlockImportWorkerMsg::Imported(results) => (results),
 			#[cfg(any(test, feature = "test-helpers"))]
 			BlockImportWorkerMsg::Synchronize => {
+				trace!(target: "sync", "Synchronizing link");
 				link.synchronized();
 				return true;
 			},
@@ -434,6 +443,7 @@ impl<B: BlockT, V: 'static + Verifier<B>> BlockImportWorker<B, V> {
 						},
 						#[cfg(any(test, feature = "test-helpers"))]
 						BlockImportWorkerMsg::Synchronize => {
+							trace!(target: "sync", "Sending sync message");
 							let _ = worker.result_sender.send(BlockImportWorkerMsg::Synchronize);
 						},
 						_ => unreachable!("Import Worker does not receive the Imported message; qed"),
@@ -118,6 +118,20 @@ impl<T: SyncOracle> SyncOracle for Arc<T> {
 	}
 }

+/// Extra verification for blocks.
+pub trait ExtraVerification<B: Block>: Send + Sync {
+	/// Future that resolves when the block is verified, or fails with error if
+	/// not.
+	type Verified: IntoFuture<Item=(),Error=String>;
+
+	/// Do additional verification for this block.
+	fn verify(
+		&self,
+		header: &B::Header,
+		body: Option<&[B::Extrinsic]>,
+	) -> Self::Verified;
+}
+
 /// A list of all well known keys in the cache.
 pub mod well_known_cache_keys {
 	/// The type representing cache keys.
@@ -24,45 +24,44 @@

 mod slots;

-pub use slots::{Slots, SlotInfo};
+pub use slots::{slot_now, SlotInfo, Slots};

+use client::ChainHead;
+use codec::{Decode, Encode};
+use consensus_common::SyncOracle;
+use futures::prelude::*;
+use futures::{
+	future::{self, Either},
+	Future, IntoFuture,
+};
+use inherents::{InherentData, InherentDataProviders};
+use log::{debug, error, info, warn};
+use runtime_primitives::generic::BlockId;
+use runtime_primitives::traits::{ApiRef, Block, ProvideRuntimeApi};
+use std::fmt::Debug;
+use std::ops::Deref;
 use std::sync::{mpsc, Arc};
 use std::thread;
-use std::fmt::Debug;
-use futures::prelude::*;
-use futures::{Future, IntoFuture, future::{self, Either}};
-use log::{warn, debug, info};
-use runtime_primitives::generic::BlockId;
-use runtime_primitives::traits::{ProvideRuntimeApi, Block, ApiRef};
-use consensus_common::SyncOracle;
-use inherents::{InherentData, InherentDataProviders};
-use client::ChainHead;
-use codec::{Encode, Decode};

 /// A worker that should be invoked at every new slot.
 pub trait SlotWorker<B: Block> {
 	/// The type of the future that will be returned when a new slot is
 	/// triggered.
-	type OnSlot: IntoFuture<Item=(), Error=consensus_common::Error>;
+	type OnSlot: IntoFuture<Item = (), Error = consensus_common::Error>;

 	/// Called when the proposer starts.
-	fn on_start(
-		&self,
-		slot_duration: u64
-	) -> Result<(), consensus_common::Error>;
+	fn on_start(&self, slot_duration: u64) -> Result<(), consensus_common::Error>;

 	/// Called when a new slot is triggered.
-	fn on_slot(
-		&self,
-		chain_head: B::Header,
-		slot_info: SlotInfo,
-	) -> Self::OnSlot;
+	fn on_slot(&self, chain_head: B::Header, slot_info: SlotInfo) -> Self::OnSlot;
 }

 /// Slot compatible inherent data.
 pub trait SlotCompatible {
 	/// Extract timestamp and slot from inherent data.
-	fn extract_timestamp_and_slot(inherent: &InherentData) -> Result<(u64, u64), consensus_common::Error>;
+	fn extract_timestamp_and_slot(
+		inherent: &InherentData,
+	) -> Result<(u64, u64), consensus_common::Error>;
 }

 /// Convert an inherent error to common error.
@@ -79,13 +78,14 @@ pub fn start_slot_worker_thread<B, C, W, SO, SC, T, OnExit>(
 	sync_oracle: SO,
 	on_exit: OnExit,
 	inherent_data_providers: InherentDataProviders,
-) -> Result<(), consensus_common::Error> where
+) -> Result<(), consensus_common::Error>
+where
 	B: Block + 'static,
 	C: ChainHead<B> + Send + Sync + 'static,
 	W: SlotWorker<B> + Send + Sync + 'static,
 	SO: SyncOracle + Send + Clone + 'static,
 	SC: SlotCompatible + 'static,
-	OnExit: Future<Item=(), Error=()> + Send + 'static,
+	OnExit: Future<Item = (), Error = ()> + Send + 'static,
 	T: SlotData + Send + Clone + 'static,
 {
 	use tokio::runtime::current_thread::Runtime;
@@ -96,7 +96,7 @@ pub fn start_slot_worker_thread<B, C, W, SO, SC, T, OnExit>(
 		let mut runtime = match Runtime::new() {
 			Ok(r) => r,
 			Err(e) => {
-				warn!("Unable to start authorship: {:?}", e);
+				warn!(target: "slots", "Unable to start authorship: {:?}", e);
 				return;
 			}
 		};
@@ -114,7 +114,7 @@ pub fn start_slot_worker_thread<B, C, W, SO, SC, T, OnExit>(
 					.send(Ok(()))
 					.expect("Receive is not dropped before receiving a result; qed");
 				slot_worker_future
-			},
+			}
 			Err(e) => {
 				result_sender
 					.send(Err(e))
@@ -126,7 +126,9 @@ pub fn start_slot_worker_thread<B, C, W, SO, SC, T, OnExit>(
 		let _ = runtime.block_on(slot_worker_future);
 	});

-	result_recv.recv().expect("Slots start thread result sender dropped")
+	result_recv
+		.recv()
+		.expect("Slots start thread result sender dropped")
 }

 /// Start a new slot worker.
@@ -137,13 +139,14 @@ pub fn start_slot_worker<B, C, W, T, SO, SC, OnExit>(
 	sync_oracle: SO,
 	on_exit: OnExit,
 	inherent_data_providers: InherentDataProviders,
-) -> Result<impl Future<Item=(), Error=()>, consensus_common::Error> where
+) -> Result<impl Future<Item = (), Error = ()>, consensus_common::Error>
+where
 	B: Block,
 	C: ChainHead<B>,
 	W: SlotWorker<B>,
 	SO: SyncOracle + Send + Clone,
 	SC: SlotCompatible,
-	OnExit: Future<Item=(), Error=()>,
+	OnExit: Future<Item = (), Error = ()>,
 	T: SlotData + Clone,
 {
 	worker.on_start(slot_duration.slot_duration())?;
@@ -174,15 +177,14 @@ pub fn start_slot_worker<B, C, W, T, SO, SC, OnExit>(
 					Ok(x) => x,
 					Err(e) => {
 						warn!(target: "slots", "Unable to author block in slot {}. \
-							no best block header: {:?}", slot_num, e);
-						return Either::B(future::ok(()))
+						no best block header: {:?}", slot_num, e);
+						return Either::B(future::ok(()));
 					}
 				};

-				Either::A(
-					worker.on_slot(chain_head, slot_info).into_future()
-						.map_err(|e| debug!(target: "slots", "Encountered consensus error: {:?}", e))
-				)
+				Either::A(worker.on_slot(chain_head, slot_info).into_future().map_err(
+					|e| warn!(target: "slots", "Encountered consensus error: {:?}", e),
+				))
 			})
 	};

@@ -230,7 +232,9 @@ pub trait SlotData {
 }

 impl SlotData for u64 {
-	fn slot_duration(&self) -> u64 { *self }
+	fn slot_duration(&self) -> u64 {
+		*self
+	}

 	const SLOT_KEY: &'static [u8] = b"aura_slot_duration";
 }
@@ -238,7 +242,25 @@ impl SlotData for u64 {
 /// A slot duration. Create with `get_or_compute`.
 // The internal member should stay private here.
 #[derive(Clone, Copy, Debug, Encode, Decode, Hash, PartialOrd, Ord, PartialEq, Eq)]
-pub struct SlotDuration<T: Clone>(T);
+pub struct SlotDuration<T>(T);
+
+impl<T> Deref for SlotDuration<T> {
+	type Target = T;
+	fn deref(&self) -> &T {
+		&self.0
+	}
+}
+
+impl<T: SlotData + Clone> SlotData for SlotDuration<T> {
+	/// Get the slot duration in milliseconds.
+	fn slot_duration(&self) -> u64
+		where T: SlotData,
+	{
+		self.0.slot_duration()
+	}
+
+	const SLOT_KEY: &'static [u8] = T::SLOT_KEY;
+}

 impl<T: Clone> SlotDuration<T> {
 	/// Either fetch the slot duration from disk or compute it from the
@@ -255,23 +277,25 @@ impl<T: Clone> SlotDuration<T> {
 		match client.get_aux(T::SLOT_KEY)? {
 			Some(v) => <T as codec::Decode>::decode(&mut &v[..])
 				.map(SlotDuration)
-				.ok_or_else(|| ::client::error::Error::Backend(
-					format!("slot duration kept in invalid format"),
-				).into()),
+				.ok_or_else(|| {
+					::client::error::Error::Backend({
+						error!(target: "slots", "slot duration kept in invalid format");
+						format!("slot duration kept in invalid format")
+					})
+					.into()
+				}),
 			None => {
 				use runtime_primitives::traits::Zero;
-				let genesis_slot_duration = cb(
-					client.runtime_api(),
-					&BlockId::number(Zero::zero()))?;
+				let genesis_slot_duration =
+					cb(client.runtime_api(), &BlockId::number(Zero::zero()))?;

 				info!(
 					"Loaded block-time = {:?} seconds from genesis on first-launch",
 					genesis_slot_duration
 				);

-				genesis_slot_duration.using_encoded(|s| {
-					client.insert_aux(&[(T::SLOT_KEY, &s[..])], &[])
-				})?;
+				genesis_slot_duration
+					.using_encoded(|s| client.insert_aux(&[(T::SLOT_KEY, &s[..])], &[]))?;

 				Ok(SlotDuration(genesis_slot_duration))
 			}
@@ -282,11 +306,4 @@ impl<T: Clone> SlotDuration<T> {
 	pub fn get(&self) -> T {
 		self.0.clone()
 	}
-
-	/// Get the slot duration in milliseconds
-	pub fn slot_duration(&self) -> u64
-		where T: SlotData
-	{
-		self.0.slot_duration()
-	}
 }
@@ -18,24 +18,34 @@
 //!
 //! This is used instead of `tokio_timer::Interval` because it was unreliable.

-use std::time::{Instant, Duration};
-use std::marker::PhantomData;
-use tokio::timer::Delay;
+use super::SlotCompatible;
+use consensus_common::{Error, ErrorKind};
 use futures::prelude::*;
 use futures::try_ready;
+use inherents::{InherentData, InherentDataProviders};
 use log::warn;
-use inherents::{InherentDataProviders, InherentData};
-use consensus_common::{Error, ErrorKind};
-use crate::SlotCompatible;
+use std::marker::PhantomData;
+use std::time::{Duration, Instant};
+use tokio::timer::Delay;

 /// Returns current duration since unix epoch.
 pub fn duration_now() -> Option<Duration> {
 	use std::time::SystemTime;

 	let now = SystemTime::now();
-	now.duration_since(SystemTime::UNIX_EPOCH).map_err(|e| {
-		warn!("Current time {:?} is before unix epoch. Something is wrong: {:?}", now, e);
-	}).ok()
+	now.duration_since(SystemTime::UNIX_EPOCH)
+		.map_err(|e| {
+			warn!(
+				"Current time {:?} is before unix epoch. Something is wrong: {:?}",
+				now, e
+			);
+		})
+		.ok()
+}
+
+/// Get the slot for now.
+pub fn slot_now(slot_duration: u64) -> Option<u64> {
+	duration_now().map(|s| s.as_secs() / slot_duration)
 }

 /// Returns the duration until the next slot, based on current duration since
@@ -113,34 +123,35 @@ impl<SC: SlotCompatible> Stream for Slots<SC> {
 		};

 		if let Some(ref mut inner_delay) = self.inner_delay {
-			try_ready!(inner_delay.poll().map_err(|e| Error::from(ErrorKind::FaultyTimer(e))));
+			try_ready!(inner_delay
+				.poll()
+				.map_err(|e| Error::from(ErrorKind::FaultyTimer(e))));
 		}

 		// timeout has fired.

-		let inherent_data = self.inherent_data_providers.create_inherent_data()
+		let inherent_data = self
+			.inherent_data_providers
+			.create_inherent_data()
 			.map_err(crate::inherent_to_common_error)?;
 		let (timestamp, slot_num) = SC::extract_timestamp_and_slot(&inherent_data)?;

 		// reschedule delay for next slot.
-		let ends_at = Instant::now() + time_until_next(Duration::from_secs(timestamp), slot_duration);
+		let ends_at =
+			Instant::now() + time_until_next(Duration::from_secs(timestamp), slot_duration);
 		self.inner_delay = Some(Delay::new(ends_at));

 		// never yield the same slot twice.
 		if slot_num > self.last_slot {
 			self.last_slot = slot_num;

-			Ok(
-				Async::Ready(
-					Some(SlotInfo {
-						number: slot_num,
-						duration: self.slot_duration,
-						timestamp,
-						ends_at,
-						inherent_data,
-					})
-				)
-			)
+			Ok(Async::Ready(Some(SlotInfo {
+				number: slot_num,
+				duration: self.slot_duration,
+				timestamp,
+				ends_at,
+				inherent_data,
+			})))
 		} else {
 			// re-poll until we get a new slot.
 			self.poll()
@@ -33,10 +33,10 @@ use fg_primitives::GrandpaApi;
 use runtime_primitives::Justification;
 use runtime_primitives::generic::BlockId;
 use runtime_primitives::traits::{
-	Block as BlockT, DigestFor, DigestItemFor, DigestItem,
+	Block as BlockT, DigestFor,
 	Header as HeaderT, NumberFor, ProvideRuntimeApi,
 };
-use substrate_primitives::{H256, ed25519, Blake2Hasher};
+use substrate_primitives::{H256, Blake2Hasher};

 use crate::{Error, CommandOrError, NewAuthoritySet, VoterCommand};
 use crate::authorities::{AuthoritySet, SharedAuthoritySet, DelayKind, PendingChange};
@@ -44,8 +44,6 @@ use crate::consensus_changes::SharedConsensusChanges;
 use crate::environment::{finalize_block, is_descendent_of};
 use crate::justification::GrandpaJustification;

-use ed25519::Public as AuthorityId;
-
 /// A block-import handler for GRANDPA.
 ///
 /// This scans each imported block for signals of changing authority set.
@@ -69,7 +67,6 @@ impl<B, E, Block: BlockT<Hash=H256>, RA, PRA> JustificationImport<Block>
 		B: Backend<Block, Blake2Hasher> + 'static,
 		E: CallExecutor<Block, Blake2Hasher> + 'static + Clone + Send + Sync,
 		DigestFor<Block>: Encode,
-		DigestItemFor<Block>: DigestItem<AuthorityId=AuthorityId>,
 		RA: Send + Sync,
 		PRA: ProvideRuntimeApi,
 		PRA::Api: GrandpaApi<Block>,
@@ -163,7 +160,6 @@ impl<B, E, Block: BlockT<Hash=H256>, RA, PRA> GrandpaBlockImport<B, E, Block, RA
 	B: Backend<Block, Blake2Hasher> + 'static,
 	E: CallExecutor<Block, Blake2Hasher> + 'static + Clone + Send + Sync,
 	DigestFor<Block>: Encode,
-	DigestItemFor<Block>: DigestItem<AuthorityId=AuthorityId>,
 	RA: Send + Sync,
 	PRA: ProvideRuntimeApi,
 	PRA::Api: GrandpaApi<Block>,
@@ -381,7 +377,6 @@ impl<B, E, Block: BlockT<Hash=H256>, RA, PRA> BlockImport<Block>
 		B: Backend<Block, Blake2Hasher> + 'static,
 		E: CallExecutor<Block, Blake2Hasher> + 'static + Clone + Send + Sync,
 		DigestFor<Block>: Encode,
-		DigestItemFor<Block>: DigestItem<AuthorityId=AuthorityId>,
 		RA: Send + Sync,
 		PRA: ProvideRuntimeApi,
 		PRA::Api: GrandpaApi<Block>,
@@ -51,7 +51,7 @@
 //! number (this is num(signal) + N). When finalizing a block, we either apply
 //! or prune any signaled changes based on whether the signaling block is
 //! included in the newly-finalized chain.
-
+#![forbid(warnings)]
 use futures::prelude::*;
 use log::{debug, info, warn};
 use futures::sync::mpsc;
@@ -62,7 +62,7 @@ use client::{
 use client::blockchain::HeaderBackend;
 use parity_codec::Encode;
 use runtime_primitives::traits::{
-	NumberFor, Block as BlockT, DigestFor, ProvideRuntimeApi, DigestItemFor, DigestItem,
+	NumberFor, Block as BlockT, DigestFor, ProvideRuntimeApi,
 };
 use fg_primitives::GrandpaApi;
 use inherents::InherentDataProviders;
@@ -362,7 +362,6 @@ fn global_communication<Block: BlockT<Hash=H256>, B, E, N, RA>(
 	N: Network<Block>,
 	RA: Send + Sync,
 	NumberFor<Block>: BlockNumberOps,
-	DigestItemFor<Block>: DigestItem<AuthorityId=AuthorityId>,
 {

 	let is_voter = local_key
@@ -463,7 +462,6 @@ pub fn run_grandpa_voter<B, E, Block: BlockT<Hash=H256>, N, RA, X>(
 	N::In: Send + 'static,
 	NumberFor<Block>: BlockNumberOps,
 	DigestFor<Block>: Encode,
-	DigestItemFor<Block>: DigestItem<AuthorityId=AuthorityId>,
 	RA: Send + Sync + 'static,
 	X: Future<Item=(),Error=()> + Clone + Send + 'static,
 {
@@ -716,7 +714,6 @@ pub fn run_grandpa<B, E, Block: BlockT<Hash=H256>, N, RA, X>(
 	N::In: Send + 'static,
 	NumberFor<Block>: BlockNumberOps,
 	DigestFor<Block>: Encode,
-	DigestItemFor<Block>: DigestItem<AuthorityId=AuthorityId>,
 	RA: Send + Sync + 'static,
 	X: Future<Item=(),Error=()> + Clone + Send + 'static,
 {
@@ -25,9 +25,8 @@ use grandpa::{
 use log::{debug, info, warn};

 use client::{CallExecutor, Client, backend::Backend};
-use ed25519::Public as AuthorityId;
-use runtime_primitives::traits::{NumberFor, Block as BlockT, DigestItemFor, DigestItem};
-use substrate_primitives::{ed25519, H256, Blake2Hasher};
+use runtime_primitives::traits::{NumberFor, Block as BlockT};
+use substrate_primitives::{ed25519::Public as AuthorityId, H256, Blake2Hasher};

 use crate::{
 	AuthoritySignature, global_communication, CommandOrError, Config, environment,
@@ -155,7 +154,6 @@ pub fn run_grandpa_observer<B, E, Block: BlockT<Hash=H256>, N, RA>(
 	N: Network<Block> + Send + Sync + 'static,
 	N::In: Send + 'static,
 	NumberFor<Block>: BlockNumberOps,
-	DigestItemFor<Block>: DigestItem<AuthorityId=AuthorityId>,
 	RA: Send + Sync + 'static,
 {
 	let LinkHalf {
@@ -23,7 +23,7 @@ use network::config::{ProtocolConfig, Roles};
 use network::consensus_gossip as network_gossip;
 use parking_lot::Mutex;
 use tokio::runtime::current_thread;
-use keyring::AuthorityKeyring;
+use keyring::ed25519::{Keyring as AuthorityKeyring};
 use client::{
 	BlockchainEvents, error::Result,
 	blockchain::Backend as BlockchainBackend,
@@ -36,7 +36,7 @@ use std::collections::{HashMap, HashSet};
 use std::result;
 use runtime_primitives::traits::{ApiRef, ProvideRuntimeApi, Header as HeaderT};
 use runtime_primitives::generic::BlockId;
-use substrate_primitives::{NativeOrEncoded, ExecutionContext};
+use substrate_primitives::{NativeOrEncoded, ExecutionContext, ed25519::Public as AuthorityId};

 use authorities::AuthoritySet;
 use communication::GRANDPA_ENGINE_ID;
@@ -290,7 +290,7 @@ impl Core<Block> for RuntimeApi {
 		_: ExecutionContext,
 		_: Option<()>,
 		_: Vec<u8>,
-	) -> Result<NativeOrEncoded<Vec<AuthorityId>>> {
+	) -> Result<NativeOrEncoded<Vec<substrate_primitives::sr25519::Public>>> {
 		unimplemented!("Not required for testing!")
 	}
 }
@@ -323,7 +323,7 @@ impl GrandpaApi<Block> for RuntimeApi {
 		_: ExecutionContext,
 		_: Option<()>,
 		_: Vec<u8>,
-	) -> Result<NativeOrEncoded<Vec<(AuthorityId, u64)>>> {
+	) -> Result<NativeOrEncoded<Vec<(substrate_primitives::ed25519::Public, u64)>>> {
 		if at == &BlockId::Number(0) {
 			Ok(self.inner.genesis_authorities.clone()).map(NativeOrEncoded::Native)
 		} else {
@@ -370,7 +370,7 @@ impl GrandpaApi<Block> for RuntimeApi {
 const TEST_GOSSIP_DURATION: Duration = Duration::from_millis(500);
 const TEST_ROUTING_INTERVAL: Duration = Duration::from_millis(50);

-fn make_ids(keys: &[AuthorityKeyring]) -> Vec<(AuthorityId, u64)> {
+fn make_ids(keys: &[AuthorityKeyring]) -> Vec<(substrate_primitives::ed25519::Public, u64)> {
 	keys.iter()
 		.map(|key| AuthorityId(key.to_raw_public()))
 		.map(|id| (id, 1))
@@ -734,7 +734,7 @@ fn justification_is_emitted_when_consensus_data_changes() {
 	let mut net = GrandpaTestNet::new(TestApi::new(make_ids(peers)), 3);

 	// import block#1 WITH consensus data change
-	let new_authorities = vec![AuthorityId::from_raw([42; 32])];
+	let new_authorities = vec![substrate_primitives::sr25519::Public::from_raw([42; 32])];
 	net.peer(0).push_authorities_change_block(new_authorities);
 	net.sync();
 	let net = Arc::new(Mutex::new(net));
@@ -114,7 +114,9 @@ impl InherentData {
 		match self.data.get(identifier) {
 			Some(inherent) =>
 				I::decode(&mut &inherent[..])
-					.ok_or_else(|| "Could not decode requested inherent type!".into())
+					.ok_or_else(|| {
+						"Could not decode requested inherent type!".into()
+					})
 					.map(Some),
 			None => Ok(None)
 		}
@@ -40,4 +40,4 @@ consensus = { package = "substrate-consensus-common", path = "../../core/consens

 [features]
 default = []
-test-helpers = ["keyring", "test_client"]
+test-helpers = ["keyring", "test_client", "consensus/test-helpers"]
@@ -435,7 +435,10 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 				return false;
 			},
 			#[cfg(any(test, feature = "test-helpers"))]
-			ProtocolMsg::Synchronize => self.network_chan.send(NetworkMsg::Synchronized),
+			ProtocolMsg::Synchronize => {
+				trace!(target: "sync", "handle_client_msg: received Synchronize msg");
+				self.network_chan.send(NetworkMsg::Synchronized)
+			}
 		}
 		true
 	}
@@ -755,6 +758,11 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 					"Peer is on different chain (our genesis: {} theirs: {})",
 					self.genesis_hash, status.genesis_hash
 				);
+				trace!(
+					target: "protocol",
+					"Peer is on different chain (our genesis: {} theirs: {})",
+					self.genesis_hash, status.genesis_hash
+				);
 				self.network_chan.send(NetworkMsg::ReportPeer(
 					who,
 					Severity::Bad(reason),
@@ -763,6 +771,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 			}
 			if status.version < MIN_VERSION && CURRENT_VERSION < status.min_supported_version {
 				let reason = format!("Peer using unsupported protocol version {}", status.version);
+				trace!(target: "protocol", "Peer {:?} using unsupported protocol version {}", who, status.version);
 				self.network_chan.send(NetworkMsg::ReportPeer(
 					who,
 					Severity::Bad(reason),
@@ -589,7 +589,7 @@ fn run_thread<B: BlockT + 'static>(
 				}
 			}
 		}
-		
+
 		Ok(Async::NotReady)
 	})
 }
@@ -848,8 +848,9 @@ impl<B: BlockT> ChainSync<B> {
 	/// Handle new block announcement.
 	pub(crate) fn on_block_announce(&mut self, protocol: &mut Context<B>, who: PeerId, hash: B::Hash, header: &B::Header) {
 		let number = *header.number();
+		debug!(target: "sync", "Received block announcement with number {:?}", number);
 		if number <= As::sa(0) {
-			trace!(target: "sync", "Ignored invalid block announcement from {}: {}", who, hash);
+			warn!(target: "sync", "Ignored invalid block announcement from {}: {}", who, hash);
 			return;
 		}
 		let parent_status = block_status(&*protocol.client(), &self.queue_blocks, header.parent_hash().clone()).ok()
@@ -40,7 +40,7 @@ use futures::sync::{mpsc, oneshot};
 use crate::message::Message;
 use network_libp2p::PeerId;
 use parking_lot::{Mutex, RwLock};
-use primitives::{H256, ed25519::Public as AuthorityId};
+use primitives::{H256, sr25519::Public as AuthorityId};
 use crate::protocol::{ConnectedPeer, Context, FromNetworkMsg, Protocol, ProtocolMsg};
 use runtime_primitives::generic::BlockId;
 use runtime_primitives::traits::{AuthorityIdFor, Block as BlockT, Digest, DigestItem, Header, NumberFor};
@@ -48,6 +48,7 @@ use runtime_primitives::{Justification, ConsensusEngineId};
 use crate::service::{network_channel, NetworkChan, NetworkLink, NetworkMsg, NetworkPort, TransactionPool};
 use crate::specialization::NetworkSpecialization;
 use test_client::{self, AccountKeyring};
+use log::debug;

 pub use test_client::runtime::{Block, Extrinsic, Hash, Transfer};
 pub use test_client::TestClient;
@@ -117,17 +118,20 @@ pub type PeersClient = client::Client<test_client::Backend, test_client::Executo
 /// A Link that can wait for a block to have been imported.
 pub struct TestLink<S: NetworkSpecialization<Block>> {
 	link: NetworkLink<Block, S>,
+
+	#[cfg(any(test, feature = "test-helpers"))]
 	network_to_protocol_sender: Sender<FromNetworkMsg<Block>>,
 }

 impl<S: NetworkSpecialization<Block>> TestLink<S> {
 	fn new(
 		protocol_sender: Sender<ProtocolMsg<Block, S>>,
-		network_to_protocol_sender: Sender<FromNetworkMsg<Block>>,
+		_network_to_protocol_sender: Sender<FromNetworkMsg<Block>>,
 		network_sender: NetworkChan<Block>
 	) -> TestLink<S> {
 		TestLink {
-			network_to_protocol_sender,
+			#[cfg(any(test, feature = "test-helpers"))]
+			network_to_protocol_sender: _network_to_protocol_sender,
 			link: NetworkLink {
 				protocol_sender,
 				network_sender,
@@ -165,8 +169,14 @@ impl<S: NetworkSpecialization<Block>> Link<Block> for TestLink<S> {
 		self.link.restart();
 	}

+	/// Send synchronization request to the block import channel.
+	///
+	/// The caller should wait for the `Link::synchronized` call to ensure that it has synchronized
+	/// with `ImportQueue`.
+	#[cfg(any(test, feature = "test-helpers"))]
 	fn synchronized(&self) {
-		let _ = self.network_to_protocol_sender.send(FromNetworkMsg::Synchronize);
+		trace!(target: "test_network", "Synchronizing");
+		drop(self.network_to_protocol_sender.send(FromNetworkMsg::Synchronize))
 	}
 }

@@ -225,12 +235,14 @@ impl<S: NetworkSpecialization<Block>> ProtocolChannel<S> {

 	/// Wait until synchronization response is generated by the protocol.
 	pub fn wait_sync(&self) -> Result<(), RecvError> {
+		trace!(target: "test_network", "Waiting for sync");
 		loop {
 			match self.protocol_to_network_receiver.receiver().recv() {
 				Ok(NetworkMsg::Synchronized) => return Ok(()),
 				Err(error) => return Err(error),
 				Ok(msg) => self.buffered_messages.lock().push_back(msg),
 			}
+			trace!(target: "test_network", "Retrying sync");
 		}
 	}

@@ -370,8 +382,11 @@ impl<D, S: NetworkSpecialization<Block>> Peer<D, S> {
 	}

 	/// Synchronize with import queue.
+	#[cfg(any(test, feature = "test-helpers"))]
 	fn import_queue_sync(&self) {
+		trace!(target: "test_network", "syncing this queue");
 		self.import_queue.synchronize();
+		trace!(target: "test_network", "wating for sync to finish");
 		let _ = self.net_proto_channel.wait_sync();
 	}

@@ -491,6 +506,7 @@ impl<D, S: NetworkSpecialization<Block>> Peer<D, S> {
 			let block = edit_block(builder);
 			let hash = block.header.hash();
 			trace!(
+				target: "test_network",
 				"Generating {}, (#{}, parent={})",
 				hash,
 				block.header.number,
@@ -610,10 +626,12 @@ pub trait TestNetFactory: Sized {

 	/// Create new test network with this many peers.
 	fn new(n: usize) -> Self {
+		trace!(target: "test_network", "Creating test network");
 		let config = Self::default_config();
 		let mut net = Self::from_config(&config);

-		for _ in 0..n {
+		for i in 0..n {
+			trace!(target: "test_network", "Adding peer {}", i);
 			net.add_peer(&config);
 		}
 		net
@@ -681,6 +699,7 @@ pub trait TestNetFactory: Sized {
 		}

 		loop {
+			debug!(target: "test_network", "loop iteration");
 			// we only deliver Status messages during start
 			let need_continue = self.route_single(true, None, &|msg| match *msg {
 				NetworkMsg::Outgoing(_, crate::message::generic::Message::Status(_)) => true,
@@ -706,6 +725,7 @@ pub trait TestNetFactory: Sized {
 		let mut to_disconnect = HashSet::new();
 		let peers = self.peers();
 		for peer in peers {
+			debug!(target: "test_network", "checking peer");
 			if let Some(message) = peer.pending_message(message_filter) {
 				match message {
 					NetworkMsg::Outgoing(recipient_id, packet) => {
@@ -744,10 +764,13 @@ pub trait TestNetFactory: Sized {
 				}
 			}
 		}
+		debug!(target: "test_network", "syncing queues");

 		// make sure that the protocol(s) has processed all messages that have been queued
 		self.peers().iter().for_each(|peer| peer.import_queue_sync());

+		debug!(target: "test_network", "queues synced");
+
 		had_messages
 	}

@@ -288,7 +288,7 @@ impl<T: AsMut<[u8]> + AsRef<[u8]> + Default + Derive> Ss58Codec for T {
 ///
 /// For now it just specifies how to create a key from a phrase and derivation path.
 #[cfg(feature = "std")]
-pub trait Pair: Sized {
+pub trait Pair: Sized + 'static {
 	/// TThe type which is used to encode a public key.
 	type Public;

@@ -18,16 +18,21 @@ use error_chain::*;
 use client;
 use crate::rpc;
 use crate::errors;
+pub use internal_errors::*;

-error_chain! {
-	foreign_links {
-		Client(client::error::Error) #[doc = "Client error"];
-	}
-	errors {
-		/// Not implemented yet
-		Unimplemented {
-			description("not yet implemented"),
-			display("Method Not Implemented"),
+#[allow(deprecated)]
+mod internal_errors {
+	use super::*;
+	error_chain! {
+		foreign_links {
+			Client(client::error::Error) #[doc = "Client error"];
+		}
+		errors {
+			/// Not implemented yet
+			Unimplemented {
+				description("not yet implemented"),
+				display("Method Not Implemented"),
+			}
 		}
 	}
 }
@@ -221,7 +221,7 @@ fn should_return_runtime_version() {

 	assert_eq!(
 		::serde_json::to_string(&api.runtime_version(None.into()).unwrap()).unwrap(),
-		r#"{"specName":"test","implName":"parity-test","authoringVersion":1,"specVersion":1,"implVersion":1,"apis":[["0xdf6acb689907609b",2],["0x37e397fc7c91f5e4",1],["0xd2bc9897eed08f15",1],["0x40fe3ad401f8959a",3],["0xc6e9a76309f39b09",1],["0xdd718d5cc53262d4",1],["0xf78b278be53f454c",1],["0x7801759919ee83e5",1]]}"#
+		r#"{"specName":"test","implName":"parity-test","authoringVersion":1,"specVersion":1,"implVersion":1,"apis":[["0xdf6acb689907609b",2],["0x37e397fc7c91f5e4",1],["0xd2bc9897eed08f15",1],["0x40fe3ad401f8959a",3],["0xc6e9a76309f39b09",1],["0xdd718d5cc53262d4",1],["0xcbca25e39f142387",1],["0xf78b278be53f454c",1],["0x7801759919ee83e5",1]]}"#
 	);
 }

@@ -246,3 +246,4 @@ fn should_notify_on_runtime_version_initially() {
 		// no more notifications on this channel
 	assert_eq!(core.block_on(next.into_future()).unwrap().0, None);
 }
+
@@ -11,7 +11,7 @@ rustc_version = "0.2"
 [dependencies]
 rstd = { package = "sr-std", path = "../sr-std", default-features = false }
 primitives = { package = "substrate-primitives", path = "../primitives", default-features = false }
-codec = { package="parity-codec", version = "3.3", default-features = false }
+codec = { package = "parity-codec", version = "3.5.1", default-features = false }
 hash-db = { version = "0.12", default-features = false }
 libsecp256k1 = { version = "0.2.1", optional = true }
 tiny-keccak = { version = "1.4.2", optional = true }
@@ -23,7 +23,7 @@ use crate::traits::{self, Checkable, Applyable, BlakeTwo256, Convert};
 use crate::generic::DigestItem as GenDigestItem;
 pub use substrate_primitives::H256;
 use substrate_primitives::U256;
-use substrate_primitives::ed25519::{Public as AuthorityId, Signature as AuthoritySignature};
+use substrate_primitives::sr25519::{Public as AuthorityId, Signature as AuthoritySignature};

 /// Authority Id
 #[derive(Default, PartialEq, Eq, Clone, Encode, Decode, Debug)]
@@ -6,7 +6,7 @@ build = "build.rs"
 edition = "2018"

 [build-dependencies]
-rustc_version = "0.2"
+rustc_version = "0.2.3"

 [features]
 default = ["std"]
@@ -29,7 +29,7 @@ pub use client::{ExecutionStrategies, blockchain, backend, self};
 pub use executor::{NativeExecutor, self};
 pub use runtime;
 pub use consensus;
-pub use keyring::{AuthorityKeyring, AccountKeyring};
+pub use keyring::{sr25519::Keyring as AuthorityKeyring, AccountKeyring};

 use std::{sync::Arc, collections::HashMap};
 use futures::future::FutureResult;
@@ -13,6 +13,7 @@ substrate-client = { path = "../client", default-features = false }
 primitives = { package = "substrate-primitives", path = "../primitives", default-features = false }
 inherents = { package = "substrate-inherents", path = "../inherents", default-features = false }
 consensus_aura = { package = "substrate-consensus-aura-primitives", path = "../consensus/aura/primitives", default-features = false }
+consensus_babe = { package = "substrate-consensus-babe-primitives", path = "../consensus/babe/primitives", default-features = false }
 rstd = { package = "sr-std", path = "../sr-std", default-features = false }
 runtime_io = { package = "sr-io", path = "../sr-io", default-features = false }
 runtime_primitives = { package = "sr-primitives", path = "../sr-primitives", default-features = false }
@@ -49,6 +50,7 @@ std = [
 	"runtime_primitives/std",
 	"runtime_version/std",
 	"consensus_aura/std",
+	"consensus_babe/std",
 	"primitives/std",
 	"substrate-trie/std",
 	"trie-db/std",
@@ -22,7 +22,7 @@ use super::AccountId;
 use parity_codec::{Encode, KeyedVec, Joiner};
 use primitives::{ChangesTrieConfiguration, map, storage::well_known_keys};
 use runtime_primitives::traits::Block;
-use primitives::ed25519::Public as AuthorityId;
+use primitives::sr25519::Public as AuthorityId;

 /// Configuration of a general Substrate test genesis block.
 pub struct GenesisConfig {
@@ -43,7 +43,7 @@ use runtime_primitives::{
 };
 use runtime_version::RuntimeVersion;
 pub use primitives::hash::H256;
-use primitives::{ed25519, sr25519, OpaqueMetadata};
+use primitives::{sr25519, OpaqueMetadata};
 #[cfg(any(feature = "std", test))]
 use runtime_version::NativeVersion;
 use inherents::{CheckInherentsResult, InherentData};
@@ -142,7 +142,7 @@ impl Extrinsic {
 }

 /// The signature type used by authorities.
-pub type AuthoritySignature = ed25519::Signature;
+pub type AuthoritySignature = sr25519::Signature;
 /// The identity type used by authorities.
 pub type AuthorityId = <AuthoritySignature as Verify>::Signer;
 /// The signature type used by accounts/transactions.
@@ -448,6 +448,16 @@ cfg_if! {
 				fn slot_duration() -> u64 { 1 }
 			}

+			impl consensus_babe::BabeApi<Block> for Runtime {
+				fn startup_data() -> consensus_babe::BabeConfiguration {
+					consensus_babe::BabeConfiguration {
+						slot_duration: 1,
+						expected_block_time: 1,
+						threshold: std::u64::MAX,
+					}
+				}
+			}
+
 			impl offchain_primitives::OffchainWorkerApi<Block> for Runtime {
 				fn offchain_worker(block: u64) {
 					let ex = Extrinsic::IncludeData(block.encode());
@@ -457,7 +467,7 @@ cfg_if! {

 			impl consensus_authorities::AuthoritiesApi<Block> for Runtime {
 				fn authorities() -> Vec<AuthorityIdFor<Block>> {
-					crate::system::authorities()
+					system::authorities()
 				}
 			}
 		}
@@ -580,6 +590,16 @@ cfg_if! {
 				fn slot_duration() -> u64 { 1 }
 			}

+			impl consensus_babe::BabeApi<Block> for Runtime {
+				fn startup_data() -> consensus_babe::BabeConfiguration {
+					consensus_babe::BabeConfiguration {
+						slot_duration: 1,
+						expected_block_time: 1,
+						threshold: core::u64::MAX,
+					}
+				}
+			}
+
 			impl offchain_primitives::OffchainWorkerApi<Block> for Runtime {
 				fn offchain_worker(block: u64) {
 					let ex = Extrinsic::IncludeData(block.encode());
@@ -589,7 +609,7 @@ cfg_if! {

 			impl consensus_authorities::AuthoritiesApi<Block> for Runtime {
 				fn authorities() -> Vec<AuthorityIdFor<Block>> {
-					crate::system::authorities()
+					system::authorities()
 				}
 			}
 		}
@@ -27,7 +27,7 @@ use runtime_primitives::{ApplyError, ApplyOutcome, ApplyResult, transaction_vali
 use parity_codec::{KeyedVec, Encode};
 use super::{AccountId, BlockNumber, Extrinsic, Transfer, H256 as Hash, Block, Header, Digest};
 use primitives::{Blake2Hasher, storage::well_known_keys};
-use primitives::ed25519::Public as AuthorityId;
+use primitives::sr25519::Public as AuthorityId;

 const NONCE_OF: &[u8] = b"nonce:";
 const BALANCE_OF: &[u8] = b"balance:";
@@ -2433,6 +2433,16 @@ dependencies = [
 "substrate-primitives 1.0.0",
 ]

+[[package]]
+name = "substrate-consensus-babe-primitives"
+version = "1.0.0"
+dependencies = [
+ "parity-codec 3.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "sr-primitives 1.0.0",
+ "substrate-client 1.0.0",
+ "substrate-consensus-slots 1.1.0",
+]
+
 [[package]]
 name = "substrate-consensus-common"
 version = "1.0.0"
@@ -2450,6 +2460,23 @@ dependencies = [
 "tokio 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

+[[package]]
+name = "substrate-consensus-slots"
+version = "1.1.0"
+dependencies = [
+ "error-chain 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-codec 3.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "sr-primitives 1.0.0",
+ "substrate-client 1.0.0",
+ "substrate-consensus-common 1.0.0",
+ "substrate-inherents 1.0.0",
+ "substrate-primitives 1.0.0",
+ "tokio 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "substrate-executor"
 version = "1.0.0"
@@ -2596,6 +2623,7 @@ dependencies = [
 "substrate-client 1.0.0",
 "substrate-consensus-aura-primitives 1.0.0",
 "substrate-consensus-authorities 1.0.0",
+ "substrate-consensus-babe-primitives 1.0.0",
 "substrate-inherents 1.0.0",
 "substrate-keyring 1.0.0",
 "substrate-offchain-primitives 0.1.0",
@@ -9,5 +9,5 @@ fi
 CARGO_INCREMENTAL=0 RUSTFLAGS="-C link-arg=--export-table" $CARGO_CMD build --target=wasm32-unknown-unknown --release
 for i in substrate_test_runtime
 do
-	wasm-gc target/wasm32-unknown-unknown/release/$i.wasm target/wasm32-unknown-unknown/release/$i.compact.wasm
+	wasm-gc "target/wasm32-unknown-unknown/release/$i.wasm" "target/wasm32-unknown-unknown/release/$i.compact.wasm"
 done
@@ -14,7 +14,7 @@ substrate-primitives = { path = "../../primitives" }
 sr-primitives = { path = "../../sr-primitives" }

 [dev-dependencies]
-assert_matches = "1.1"
-env_logger = "0.6"
-parity-codec = "3.3"
+assert_matches = "1.3.0"
+env_logger = "0.6.1"
+parity-codec = "3.5.1"
 test_runtime = { package = "substrate-test-runtime", path = "../../test-runtime" }
@@ -58,8 +58,8 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	spec_name: create_runtime_str!("node"),
 	impl_name: create_runtime_str!("substrate-node"),
 	authoring_version: 10,
-	spec_version: 67,
-	impl_version: 68,
+	spec_version: 69,
+	impl_version: 70,
 	apis: RUNTIME_API_VERSIONS,
 };

@@ -5,14 +5,14 @@
 set -e

 PROJECT_ROOT=`git rev-parse --show-toplevel`
-source `dirname "$0"`/common.sh
+source "`dirname \"$0\"`/common.sh"

 export CARGO_INCREMENTAL=0

 # Save current directory.
 pushd .

-cd $ROOT
+cd -- "$ROOT"

 for SRC in "${SRCS[@]}"
 do
@@ -0,0 +1,41 @@
+[package]
+name = "srml-babe"
+version = "0.1.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2018"
+
+[dependencies]
+hex-literal = "0.1.4"
+parity-codec = { version = "3.5.1", default-features = false, features = ["derive"] }
+serde = { version = "1.0.90", optional = true }
+inherents = { package = "substrate-inherents", path = "../../core/inherents", default-features = false }
+rstd = { package = "sr-std", path = "../../core/sr-std", default-features = false }
+primitives = { package = "sr-primitives", path = "../../core/sr-primitives", default-features = false }
+srml-support = { path = "../support", default-features = false }
+system = { package = "srml-system", path = "../system", default-features = false }
+timestamp = { package = "srml-timestamp", path = "../timestamp", default-features = false }
+staking = { package = "srml-staking", path = "../staking", default-features = false }
+session = { package = "srml-session", path = "../session", default-features = false }
+babe-primitives = { package = "substrate-consensus-babe-primitives", path = "../../core/consensus/babe/primitives", default-features = false }
+
+[dev-dependencies]
+lazy_static = "1.3.0"
+parking_lot = "0.7.1"
+substrate-primitives = { path = "../../core/primitives" }
+runtime_io = { package = "sr-io", path = "../../core/sr-io" }
+consensus = { package = "srml-consensus", path = "../consensus" }
+
+[features]
+default = ["std"]
+std = [
+	"serde",
+	"parity-codec/std",
+	"rstd/std",
+	"srml-support/std",
+	"primitives/std",
+	"system/std",
+	"timestamp/std",
+	"staking/std",
+	"inherents/std",
+	"babe-primitives/std",
+]
@@ -0,0 +1,155 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate 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.
+
+// Substrate 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 Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Consensus extension module for BABE consensus.
+
+#![cfg_attr(not(feature = "std"), no_std)]
+#![forbid(unsafe_code, warnings)]
+pub use timestamp;
+
+use rstd::{result, prelude::*};
+use srml_support::{decl_storage, decl_module};
+use primitives::traits::As;
+use timestamp::{OnTimestampSet, Trait};
+#[cfg(feature = "std")]
+use timestamp::TimestampInherentData;
+use parity_codec::Decode;
+use inherents::{RuntimeString, InherentIdentifier, InherentData, ProvideInherent, MakeFatalError};
+#[cfg(feature = "std")]
+use inherents::{InherentDataProviders, ProvideInherentData};
+
+/// The BABE inherent identifier.
+pub const INHERENT_IDENTIFIER: InherentIdentifier = *b"babeslot";
+
+/// The type of the BABE inherent.
+pub type InherentType = u64;
+
+/// Auxiliary trait to extract BABE inherent data.
+pub trait BabeInherentData {
+	/// Get BABE inherent data.
+	fn babe_inherent_data(&self) -> result::Result<InherentType, RuntimeString>;
+	/// Replace BABE inherent data.
+	fn babe_replace_inherent_data(&mut self, new: InherentType);
+}
+
+impl BabeInherentData for InherentData {
+	fn babe_inherent_data(&self) -> result::Result<InherentType, RuntimeString> {
+		self.get_data(&INHERENT_IDENTIFIER)
+			.and_then(|r| r.ok_or_else(|| "BABE inherent data not found".into()))
+	}
+
+	fn babe_replace_inherent_data(&mut self, new: InherentType) {
+		self.replace_data(INHERENT_IDENTIFIER, &new);
+	}
+}
+
+/// Provides the slot duration inherent data for BABE.
+#[cfg(feature = "std")]
+pub struct InherentDataProvider {
+	slot_duration: u64,
+}
+
+#[cfg(feature = "std")]
+impl InherentDataProvider {
+	pub fn new(slot_duration: u64) -> Self {
+		Self {
+			slot_duration
+		}
+	}
+}
+
+#[cfg(feature = "std")]
+impl ProvideInherentData for InherentDataProvider {
+	fn on_register(
+		&self,
+		providers: &InherentDataProviders,
+	) -> result::Result<(), RuntimeString> {
+		if !providers.has_provider(&timestamp::INHERENT_IDENTIFIER) {
+			// Add the timestamp inherent data provider, as we require it.
+			providers.register_provider(timestamp::InherentDataProvider)
+		} else {
+			Ok(())
+		}
+	}
+
+	fn inherent_identifier(&self) -> &'static inherents::InherentIdentifier {
+		&INHERENT_IDENTIFIER
+	}
+
+	fn provide_inherent_data(
+		&self,
+		inherent_data: &mut InherentData,
+	) -> result::Result<(), RuntimeString> {
+		let timestamp = inherent_data.timestamp_inherent_data()?;
+		let slot_num = timestamp / self.slot_duration;
+		inherent_data.put_data(INHERENT_IDENTIFIER, &slot_num)
+	}
+
+	fn error_to_string(&self, error: &[u8]) -> Option<String> {
+		RuntimeString::decode(&mut &error[..]).map(Into::into)
+	}
+}
+
+decl_storage! {
+	trait Store for Module<T: Trait> as Babe {
+		// The last timestamp.
+		LastTimestamp get(last): T::Moment;
+	}
+}
+
+decl_module! {
+	pub struct Module<T: Trait> for enum Call where origin: T::Origin { }
+}
+
+impl<T: Trait> Module<T> {
+	/// Determine the BABE slot duration based on the Timestamp module configuration.
+	pub fn slot_duration() -> u64 {
+		// we double the minimum block-period so each author can always propose within
+		// the majority of their slot.
+		<timestamp::Module<T>>::minimum_period().as_().saturating_mul(2)
+	}
+}
+
+impl<T: Trait> OnTimestampSet<T::Moment> for Module<T> {
+	fn on_timestamp_set(_moment: T::Moment) { }
+}
+
+impl<T: Trait> ProvideInherent for Module<T> {
+	type Call = timestamp::Call<T>;
+	type Error = MakeFatalError<RuntimeString>;
+	const INHERENT_IDENTIFIER: InherentIdentifier = INHERENT_IDENTIFIER;
+
+	fn create_inherent(_: &InherentData) -> Option<Self::Call> {
+		None
+	}
+
+	fn check_inherent(call: &Self::Call, data: &InherentData) -> result::Result<(), Self::Error> {
+		let timestamp = match call {
+			timestamp::Call::set(ref timestamp) => timestamp.clone(),
+			_ => return Ok(()),
+		};
+
+		let timestamp_based_slot = timestamp.as_() / Self::slot_duration();
+
+		let seal_slot = data.babe_inherent_data()?;
+
+		if timestamp_based_slot == seal_slot {
+			Ok(())
+		} else {
+			Err(RuntimeString::from("timestamp set in block doesn’t match slot in seal").into())
+		}
+	}
+}
@@ -142,7 +142,7 @@ use inherents::{
 };

 #[cfg(any(feature = "std", test))]
-use substrate_primitives::ed25519::Public as AuthorityId;
+use substrate_primitives::sr25519::Public as AuthorityId;

 mod mock;
 mod tests;