Include a reference to the validation data in the candidate descriptor (#1442)

* rename GlobalValidationSchedule to GlobalValidationData

* guide: update candidate descriptor to contain validation data hash

* guide: add note in inclusion module about checking validation data hash

* primitives: update CandidateDescriptor to contain new hash

* fix payload computation

* add helpers for computing validation data to runtime modules

* guide: note routines

* inclusion: check validation data hash and fix local_validation_data bug

* add a case to candidate_checks and improve that test substantially

* bump versions

* address review comments

* add a test for including code upgrade

* bump kusama version

* bump westend & polkadot versions

collator/src/lib.rs

@@ -58,7 +58,7 @@ use sp_core::Pair;
 use polkadot_primitives::v0::{
 	BlockId, Hash, Block, DownwardMessage,
 	BlockData, DutyRoster, HeadData, Id as ParaId,
-	PoVBlock, ValidatorId, CollatorPair, LocalValidationData, GlobalValidationSchedule,
+	PoVBlock, ValidatorId, CollatorPair, LocalValidationData, GlobalValidationData,
 	Collation, CollationInfo, collator_signature_payload,
 };
 use polkadot_cli::{
@@ -148,7 +148,7 @@ pub trait ParachainContext: Clone {
 	fn produce_candidate(
 		&mut self,
 		relay_parent: Hash,
-		global_validation: GlobalValidationSchedule,
+		global_validation: GlobalValidationData,
 		local_validation: LocalValidationData,
 		downward_messages: Vec<DownwardMessage>,
 	) -> Self::ProduceCandidate;
@@ -158,7 +158,7 @@ pub trait ParachainContext: Clone {
 pub async fn collate<P>(
 	relay_parent: Hash,
 	local_id: ParaId,
-	global_validation: GlobalValidationSchedule,
+	global_validation: GlobalValidationData,
 	local_validation_data: LocalValidationData,
 	downward_messages: Vec<DownwardMessage>,
 	mut para_context: P,
@@ -315,7 +315,7 @@ fn build_collator_service<P, C, R, Extrinsic>(
 
 			let work = future::lazy(move |_| {
 				let api = client.runtime_api();
-				let global_validation = try_fr!(api.global_validation_schedule(&id));
+				let global_validation = try_fr!(api.global_validation_data(&id));
 				let local_validation = match try_fr!(api.local_validation_data(&id, para_id)) {
 					Some(local_validation) => local_validation,
 					None => return future::Either::Left(future::ok(())),
@@ -477,7 +477,7 @@ mod tests {
 		fn produce_candidate(
 			&mut self,
 			_relay_parent: Hash,
-			_global: GlobalValidationSchedule,
+			_global: GlobalValidationData,
 			_local_validation: LocalValidationData,
 			_: Vec<DownwardMessage>,
 		) -> Self::ProduceCandidate {

network/src/protocol/tests.rs

@@ -21,7 +21,7 @@ use polkadot_primitives::v0::{
 	Block,
 	Id as ParaId, Chain, DutyRoster, ParachainHost, ValidatorId,
 	Retriable, CollatorId, AbridgedCandidateReceipt,
-	GlobalValidationSchedule, LocalValidationData, ErasureChunk, SigningContext,
+	GlobalValidationData, LocalValidationData, ErasureChunk, SigningContext,
 	PoVBlock, BlockData, ValidationCode,
 };
 use polkadot_validation::{SharedTable, TableRouter};
@@ -180,7 +180,7 @@ sp_api::mock_impl_runtime_apis! {
 			Some(ValidationCode(Vec::new()))
 		}
 
-		fn global_validation_schedule() -> GlobalValidationSchedule {
+		fn global_validation_data() -> GlobalValidationData {
 			Default::default()
 		}
 

node/core/backing/src/lib.rs

@@ -606,7 +606,7 @@ impl CandidateBackingJob {
 		with_commitments: impl FnOnce(CandidateCommitments) -> Result<T, E>,
 	) -> Result<Result<T, E>, Error> {
 		let omitted_validation = OmittedValidationData {
-			global_validation: outputs.global_validation_schedule,
+			global_validation: outputs.global_validation_data,
 			local_validation: outputs.local_validation_data,
 		};
 
@@ -773,7 +773,7 @@ mod tests {
 	use futures::{executor, future, Future};
 	use polkadot_primitives::v1::{
 		AssignmentKind, BlockData, CandidateCommitments, CollatorId, CoreAssignment, CoreIndex,
-		LocalValidationData, GlobalValidationSchedule, GroupIndex, HeadData,
+		LocalValidationData, GlobalValidationData, GroupIndex, HeadData,
 		ValidatorPair, ValidityAttestation,
 	};
 	use polkadot_subsystem::{
@@ -792,7 +792,7 @@ mod tests {
 		keystore: KeyStorePtr,
 		validators: Vec<Sr25519Keyring>,
 		validator_public: Vec<ValidatorId>,
-		global_validation_schedule: GlobalValidationSchedule,
+		global_validation_data: GlobalValidationData,
 		local_validation_data: LocalValidationData,
 		roster: SchedulerRoster,
 		head_data: HashMap<ParaId, HeadData>,
@@ -877,7 +877,7 @@ mod tests {
 				validation_code_hash: Default::default(),
 			};
 
-			let global_validation_schedule = GlobalValidationSchedule {
+			let global_validation_data = GlobalValidationData {
 				max_code_size: 1000,
 				max_head_data_size: 1000,
 				block_number: Default::default(),
@@ -891,7 +891,7 @@ mod tests {
 				roster,
 				head_data,
 				local_validation_data,
-				global_validation_schedule,
+				global_validation_data,
 				signing_context,
 				relay_parent,
 			}
@@ -921,7 +921,7 @@ mod tests {
 
 	fn make_erasure_root(test: &TestState, pov: PoV) -> Hash {
 		let omitted_validation = OmittedValidationData {
-			global_validation: test.global_validation_schedule.clone(),
+			global_validation: test.global_validation_data.clone(),
 			local_validation: test.local_validation_data.clone(),
 		};
 
@@ -1048,7 +1048,7 @@ mod tests {
 				) if pov == pov && &c == candidate.descriptor() => {
 					tx.send(Ok(
 						ValidationResult::Valid(ValidationOutputs {
-							global_validation_schedule: test_state.global_validation_schedule,
+							global_validation_data: test_state.global_validation_data,
 							local_validation_data: test_state.local_validation_data,
 							head_data: expected_head_data.clone(),
 							upward_messages: Vec::new(),
@@ -1160,7 +1160,7 @@ mod tests {
 				) if pov == pov && &c == candidate_a.descriptor() => {
 					tx.send(Ok(
 						ValidationResult::Valid(ValidationOutputs {
-							global_validation_schedule: test_state.global_validation_schedule,
+							global_validation_data: test_state.global_validation_data,
 							local_validation_data: test_state.local_validation_data,
 							head_data: expected_head_data.clone(),
 							upward_messages: Vec::new(),
@@ -1281,7 +1281,7 @@ mod tests {
 				) if pov == pov && &c == candidate_a.descriptor() => {
 					tx.send(Ok(
 						ValidationResult::Valid(ValidationOutputs {
-							global_validation_schedule: test_state.global_validation_schedule,
+							global_validation_data: test_state.global_validation_data,
 							local_validation_data: test_state.local_validation_data,
 							head_data: expected_head_data.clone(),
 							upward_messages: Vec::new(),
@@ -1438,7 +1438,7 @@ mod tests {
 				) if pov == pov && &c == candidate_b.descriptor() => {
 					tx.send(Ok(
 						ValidationResult::Valid(ValidationOutputs {
-							global_validation_schedule: test_state.global_validation_schedule,
+							global_validation_data: test_state.global_validation_data,
 							local_validation_data: test_state.local_validation_data,
 							head_data: expected_head_data.clone(),
 							upward_messages: Vec::new(),

node/primitives/src/lib.rs

@@ -24,7 +24,7 @@ use parity_scale_codec::{Decode, Encode};
 use polkadot_primitives::v1::{
 	Hash, CommittedCandidateReceipt, CandidateReceipt, CompactStatement,
 	EncodeAs, Signed, SigningContext, ValidatorIndex, ValidatorId,
-	UpwardMessage, Balance, ValidationCode, GlobalValidationSchedule, LocalValidationData,
+	UpwardMessage, Balance, ValidationCode, GlobalValidationData, LocalValidationData,
 	HeadData,
 };
 use polkadot_statement_table::{
@@ -118,7 +118,7 @@ pub struct ValidationOutputs {
 	/// The head-data produced by validation.
 	pub head_data: HeadData,
 	/// The global validation schedule.
-	pub global_validation_schedule: GlobalValidationSchedule,
+	pub global_validation_data: GlobalValidationData,
 	/// The local validation data.
 	pub local_validation_data: LocalValidationData,
 	/// Upward messages to the relay chain.

parachain/test-parachains/adder/collator/src/main.rs

@@ -24,7 +24,7 @@ use sp_core::Pair;
 use codec::{Encode, Decode};
 use primitives::v0::{
 	Hash, DownwardMessage,
-	HeadData, BlockData, Id as ParaId, LocalValidationData, GlobalValidationSchedule,
+	HeadData, BlockData, Id as ParaId, LocalValidationData, GlobalValidationData,
 };
 use collator::{ParachainContext, Network, BuildParachainContext, Cli, SubstrateCli};
 use parking_lot::Mutex;
@@ -58,7 +58,7 @@ impl ParachainContext for AdderContext {
 	fn produce_candidate(
 		&mut self,
 		_relay_parent: Hash,
-		_global_validation: GlobalValidationSchedule,
+		_global_validation: GlobalValidationData,
 		local_validation: LocalValidationData,
 		_: Vec<DownwardMessage>,
 	) -> Self::ProduceCandidate

primitives/src/v0.rs

@@ -179,7 +179,7 @@ pub struct DutyRoster {
 /// These are global parameters that apply to all parachain candidates in a block.
 #[derive(PartialEq, Eq, Clone, Encode, Decode)]
 #[cfg_attr(feature = "std", derive(Debug, Default))]
-pub struct GlobalValidationSchedule<N = BlockNumber> {
+pub struct GlobalValidationData<N = BlockNumber> {
 	/// The maximum code size permitted, in bytes.
 	pub max_code_size: u32,
 	/// The maximum head-data size permitted, in bytes.
@@ -278,7 +278,7 @@ pub struct CandidateReceipt<H = Hash, N = BlockNumber> {
 	/// The hash of the PoV-block.
 	pub pov_block_hash: H,
 	/// The global validation schedule.
-	pub global_validation: GlobalValidationSchedule<N>,
+	pub global_validation: GlobalValidationData<N>,
 	/// The local validation data.
 	pub local_validation: LocalValidationData<N>,
 	/// Commitments made as a result of validation.
@@ -352,7 +352,7 @@ impl Ord for CandidateReceipt {
 #[cfg_attr(feature = "std", derive(Debug, Default))]
 pub struct OmittedValidationData<N = BlockNumber> {
 	/// The global validation schedule.
-	pub global_validation: GlobalValidationSchedule<N>,
+	pub global_validation: GlobalValidationData<N>,
 	/// The local validation data.
 	pub local_validation: LocalValidationData<N>,
 }
@@ -762,7 +762,7 @@ sp_api::decl_runtime_apis! {
 		fn active_parachains() -> Vec<(Id, Option<(CollatorId, Retriable)>)>;
 		/// Get the global validation schedule that all parachains should
 		/// be validated under.
-		fn global_validation_schedule() -> GlobalValidationSchedule;
+		fn global_validation_data() -> GlobalValidationData;
 		/// Get the local validation data for a particular parachain.
 		fn local_validation_data(id: Id) -> Option<LocalValidationData>;
 		/// Get the given parachain's head code blob.

primitives/src/v1.rs

@@ -60,14 +60,16 @@ pub const INCLUSION_INHERENT_IDENTIFIER: InherentIdentifier = *b"inclusn0";
 pub fn collator_signature_payload<H: AsRef<[u8]>>(
 	relay_parent: &H,
 	para_id: &Id,
+	validation_data_hash: &Hash,
 	pov_hash: &Hash,
-) -> [u8; 68] {
+) -> [u8; 100] {
 	// 32-byte hash length is protected in a test below.
-	let mut payload = [0u8; 68];
+	let mut payload = [0u8; 100];
 
 	payload[0..32].copy_from_slice(relay_parent.as_ref());
 	u32::from(*para_id).using_encoded(|s| payload[32..32 + s.len()].copy_from_slice(s));
-	payload[36..68].copy_from_slice(pov_hash.as_ref());
+	payload[36..68].copy_from_slice(validation_data_hash.as_ref());
+	payload[68..100].copy_from_slice(pov_hash.as_ref());
 
 	payload
 }
@@ -75,11 +77,18 @@ pub fn collator_signature_payload<H: AsRef<[u8]>>(
 fn check_collator_signature<H: AsRef<[u8]>>(
 	relay_parent: &H,
 	para_id: &Id,
+	validation_data_hash: &Hash,
 	pov_hash: &Hash,
 	collator: &CollatorId,
 	signature: &CollatorSignature,
 ) -> Result<(),()> {
-	let payload = collator_signature_payload(relay_parent, para_id, pov_hash);
+	let payload = collator_signature_payload(
+		relay_parent,
+		para_id,
+		validation_data_hash,
+		pov_hash,
+	);
+
 	if signature.verify(&payload[..], collator) {
 		Ok(())
 	} else {
@@ -87,6 +96,14 @@ fn check_collator_signature<H: AsRef<[u8]>>(
 	}
 }
 
+/// Compute the `validation_data_hash` from global & local validation data.
+pub fn validation_data_hash<N: Encode>(
+	global: &GlobalValidationData<N>,
+	local: &LocalValidationData<N>,
+) -> Hash {
+	BlakeTwo256::hash_of(&(global, local))
+}
+
 /// A unique descriptor of the candidate receipt.
 #[derive(PartialEq, Eq, Clone, Encode, Decode)]
 #[cfg_attr(feature = "std", derive(Debug, Default))]
@@ -97,11 +114,16 @@ pub struct CandidateDescriptor<H = Hash> {
 	pub relay_parent: H,
 	/// The collator's sr25519 public key.
 	pub collator: CollatorId,
-	/// Signature on blake2-256 of components of this receipt:
-	/// The parachain index, the relay parent, and the pov_hash.
-	pub signature: CollatorSignature,
+	/// The blake2-256 hash of the validation data. This is extra data derived from
+	/// relay-chain state which may vary based on bitfields included before the candidate.
+	/// Thus it cannot be derived entirely from the relay-parent.
+	pub validation_data_hash: Hash,
 	/// The blake2-256 hash of the pov.
 	pub pov_hash: Hash,
+	/// Signature on blake2-256 of components of this receipt:
+	/// The parachain index, the relay parent, the validation data hash, and the pov_hash.
+	pub signature: CollatorSignature,
+
 }
 
 impl<H: AsRef<[u8]>> CandidateDescriptor<H> {
@@ -110,6 +132,7 @@ impl<H: AsRef<[u8]>> CandidateDescriptor<H> {
 		check_collator_signature(
 			&self.relay_parent,
 			&self.para_id,
+			&self.validation_data_hash,
 			&self.pov_hash,
 			&self.collator,
 			&self.signature,
@@ -146,7 +169,7 @@ pub struct FullCandidateReceipt<H = Hash, N = BlockNumber> {
 	/// The inner candidate receipt.
 	pub inner: CandidateReceipt<H>,
 	/// The global validation schedule.
-	pub global_validation: GlobalValidationSchedule<N>,
+	pub global_validation: GlobalValidationData<N>,
 	/// The local validation data.
 	pub local_validation: LocalValidationData<N>,
 }
@@ -232,7 +255,7 @@ pub struct LocalValidationData<N = BlockNumber> {
 /// These are global parameters that apply to all candidates in a block.
 #[derive(PartialEq, Eq, Clone, Encode, Decode)]
 #[cfg_attr(feature = "std", derive(Debug, Default))]
-pub struct GlobalValidationSchedule<N = BlockNumber> {
+pub struct GlobalValidationData<N = BlockNumber> {
 	/// The maximum code size permitted, in bytes.
 	pub max_code_size: u32,
 	/// The maximum head-data size permitted, in bytes.
@@ -465,7 +488,7 @@ impl CoreAssignment {
 #[cfg_attr(feature = "std", derive(PartialEq, Debug))]
 pub struct OmittedValidationData {
 	/// The global validation schedule.
-	pub global_validation: GlobalValidationSchedule,
+	pub global_validation: GlobalValidationData,
 	/// The local validation data.
 	pub local_validation: LocalValidationData,
 }
@@ -636,9 +659,9 @@ sp_api::decl_runtime_apis! {
 		/// cores can have paras assigned to them.
 		fn availability_cores() -> Vec<CoreState<N>>;
 
-		/// Yields the GlobalValidationSchedule. This applies to all para candidates with the
+		/// Yields the GlobalValidationData. This applies to all para candidates with the
 		/// relay-parent equal to the block in which context this is invoked in.
-		fn global_validation_schedule() -> GlobalValidationSchedule<N>;
+		fn global_validation_data() -> GlobalValidationData<N>;
 
 		/// Yields the LocalValidationData for the given ParaId along with an assumption that
 		/// should be used if the para currently occupies a core.
@@ -696,4 +719,18 @@ mod tests {
 		assert_eq!(info.next_rotation_at(), 0);
 		assert_eq!(info.last_rotation_at(), 0);
 	}
+
+	#[test]
+	fn collator_signature_payload_is_valid() {
+		// if this fails, collator signature verification code has to be updated.
+		let h = Hash::default();
+		assert_eq!(h.as_ref().len(), 32);
+
+		let _payload = collator_signature_payload(
+			&Hash::from([1; 32]),
+			&5u32.into(),
+			&Hash::from([2; 32]),
+			&Hash::from([3; 32]),
+		);
+	}
 }

roadmap/implementers-guide/src/runtime-api/README.md

@@ -137,10 +137,10 @@ enum CoreState {
 
 ## Global Validation Schedule
 
-Yields the [`GlobalValidationSchedule`](../types/candidate.md#globalvalidationschedule) at the state of a given block. This applies to all para candidates with the relay-parent equal to that block.
+Yields the [`GlobalValidationData`](../types/candidate.md#globalvalidationschedule) at the state of a given block. This applies to all para candidates with the relay-parent equal to that block.
 
 ```rust
-fn global_validation_schedule(at: Block) -> GlobalValidationSchedule;
+fn global_validation_data(at: Block) -> GlobalValidationData;
 ```
 
 ## Local Validation Data

roadmap/implementers-guide/src/runtime/configuration.md

@@ -35,6 +35,9 @@ fn update_configuration(f: impl FnOnce(&mut HostConfiguration)) {
     *pending = Some(x);
   })
 }
+
+/// Get the GlobalValidationData, assuming the context is the parent block.
+fn global_validation_data() -> GlobalValidationData;
 ```
 
 ## Entry-points

roadmap/implementers-guide/src/runtime/inclusion.md

@@ -62,6 +62,7 @@ All failed checks should lead to an unrecoverable error making the block invalid
   1. check that each candidate corresponds to a scheduled core and that they are ordered in the same order the cores appear in assignments in `scheduled`.
   1. check that `scheduled` is sorted ascending by `CoreIndex`, without duplicates.
   1. check that there is no candidate pending availability for any scheduled `ParaId`.
+  1. check that each candidate's `validation_data_hash` corresponds to a `(LocalValidationData, GlobalValidationData)` computed from the current state.
   1. If the core assignment includes a specific collator, ensure the backed candidate is issued by that collator.
   1. Ensure that any code upgrade scheduled by the candidate does not happen within `config.validation_upgrade_frequency` of `Paras::last_code_upgrade(para_id, true)`, if any, comparing against the value of `Paras::FutureCodeUpgrades` for the given para ID.
   1. Check the collator's signature on the candidate data.

roadmap/implementers-guide/src/runtime/paras.md

@@ -112,6 +112,7 @@ OutgoingParas: Vec<ParaId>;
 * `is_parathread(ParaId) -> bool`: Returns true if the para ID references any live parathread.
 
 * `last_code_upgrade(id: ParaId, include_future: bool) -> Option<BlockNumber>`: The block number of the last scheduled upgrade of the requested para. Includes future upgrades if the flag is set. This is the `expected_at` number, not the `activated_at` number.
+* `local_validation_data(id: ParaId) -> Option<LocalValidationData>`: Get the LocalValidationData of the given para, assuming the context is the parent block. Returns `None` if the para is not known.
 
 ## Finalization
 

roadmap/implementers-guide/src/types/availability.md

@@ -26,12 +26,12 @@ struct PoV(Vec<u8>);
 
 Validation data that is often omitted from types describing candidates as it can be derived from the relay-parent of the candidate. However, with the expectation of state pruning, these are best kept available elsewhere as well.
 
-This contains the [`GlobalValidationSchedule`](candidate.md#globalvalidationschedule) and [`LocalValidationData`](candidate.md#localvalidationdata)
+This contains the [`GlobalValidationData`](candidate.md#globalvalidationschedule) and [`LocalValidationData`](candidate.md#localvalidationdata)