Build block without checking signatures (#4916)

* in executive

* in other places

* to UnsafeResult

* move doc comment

* apply suggestions

* allow validity mocking for TestXt

* add test

* augment checkable instead of another trait

* fix im online test

* blockbuilder dihotomy

* review suggestions

* update test

* Update client/block-builder/src/lib.rs

* updae spec_version

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

substrate/client/basic-authorship/src/basic_authorship.rs

@@ -195,7 +195,7 @@ impl<Block, B, E, RA, A> ProposerInner<Block, SubstrateClient<B, E, Block, RA>,
 				inherent_data
 			)?
 		{
-			block_builder.push(extrinsic)?;
+			block_builder.push_trusted(extrinsic)?;
 		}
 
 		// proceed with transactions
@@ -218,7 +218,7 @@ impl<Block, B, E, RA, A> ProposerInner<Block, SubstrateClient<B, E, Block, RA>,
 			let pending_tx_data = pending_tx.data().clone();
 			let pending_tx_hash = pending_tx.hash().clone();
 			trace!("[{:?}] Pushing to the block.", pending_tx_hash);
-			match sc_block_builder::BlockBuilder::push(&mut block_builder, pending_tx_data) {
+			match sc_block_builder::BlockBuilder::push_trusted(&mut block_builder, pending_tx_data) {
 				Ok(()) => {
 					debug!("[{:?}] Pushed to the block.", pending_tx_hash);
 				}

substrate/client/block-builder/src/lib.rs

@@ -121,11 +121,23 @@ where
 			backend,
 		})
 	}
+	
+	/// Push onto the block's list of extrinsics.
+	///
+	/// This will ensure the extrinsic can be validly executed (by executing it).
+	pub fn push(&mut self, xt: <Block as BlockT>::Extrinsic) -> Result<(), ApiErrorFor<A, Block>> {
+		self.push_internal(xt, false)
+	}
 
 	/// Push onto the block's list of extrinsics.
 	///
-	/// This will ensure the extrinsic can be validly executed (by executing it);
-	pub fn push(&mut self, xt: <Block as BlockT>::Extrinsic) -> Result<(), ApiErrorFor<A, Block>> {
+	/// This will treat incoming extrinsic `xt` as untrusted and perform additional checks
+	/// (currenty checking signature).
+	pub fn push_trusted(&mut self, xt: <Block as BlockT>::Extrinsic) -> Result<(), ApiErrorFor<A, Block>> {
+		self.push_internal(xt, true)
+	}
+
+	fn push_internal(&mut self, xt: <Block as BlockT>::Extrinsic, skip_signature: bool) -> Result<(), ApiErrorFor<A, Block>> {
 		let block_id = &self.block_id;
 		let extrinsics = &mut self.extrinsics;
 
@@ -152,12 +164,29 @@ where
 				}
 			})
 		} else {
-			self.api.map_api_result(|api| {
-				match api.apply_extrinsic_with_context(
+			let use_trusted = skip_signature && self
+				.api
+				.has_api_with::<dyn BlockBuilderApi<Block, Error = ApiErrorFor<A, Block>>, _>(
 					block_id,
-					ExecutionContext::BlockConstruction,
-					xt.clone(),
-				)? {
+					|version| version >= 5,
+				)?;
+
+			self.api.map_api_result(|api| {
+				let apply_result = if use_trusted {
+					api.apply_trusted_extrinsic_with_context(
+						block_id,
+						ExecutionContext::BlockConstruction,
+						xt.clone(),
+					)?
+				} else  { 
+					api.apply_extrinsic_with_context(
+						block_id,
+						ExecutionContext::BlockConstruction,
+						xt.clone(),
+					)?
+				};
+
+				match apply_result {
 					Ok(_) => {
 						extrinsics.push(xt);
 						Ok(())

substrate/client/rpc/src/state/tests.rs

@@ -402,7 +402,7 @@ fn should_return_runtime_version() {
 
 	let result = "{\"specName\":\"test\",\"implName\":\"parity-test\",\"authoringVersion\":1,\
 		\"specVersion\":1,\"implVersion\":2,\"apis\":[[\"0xdf6acb689907609b\",2],\
-		[\"0x37e397fc7c91f5e4\",1],[\"0xd2bc9897eed08f15\",1],[\"0x40fe3ad401f8959a\",4],\
+		[\"0x37e397fc7c91f5e4\",1],[\"0xd2bc9897eed08f15\",1],[\"0x40fe3ad401f8959a\",5],\
 		[\"0xc6e9a76309f39b09\",1],[\"0xdd718d5cc53262d4\",1],[\"0xcbca25e39f142387\",1],\
 		[\"0xf78b278be53f454c\",2],[\"0xab3c0572291feb8b\",1],[\"0xbc9d89904f5b923f\",1]]}";
 

substrate/client/service/src/lib.rs

@@ -705,6 +705,7 @@ mod tests {
 	use futures::executor::block_on;
 	use sp_consensus::SelectChain;
 	use sp_runtime::traits::BlindCheckable;
+	use sp_runtime::generic::CheckSignature;
 	use substrate_test_runtime_client::{prelude::*, runtime::{Extrinsic, Transfer}};
 	use sc_transaction_pool::{BasicPool, FullChainApi};
 
@@ -733,7 +734,7 @@ mod tests {
 
 		// then
 		assert_eq!(transactions.len(), 1);
-		assert!(transactions[0].1.clone().check().is_ok());
+		assert!(transactions[0].1.clone().check(CheckSignature::Yes).is_ok());
 		// this should not panic
 		let _ = transactions[0].1.transfer();
 	}