Propagate message verification errors (#2114)

* Propagate message verification errors

* Replace parse_finalized_storage_proof() with storage_proof_checker()

* small fixes

* fix comment

bridges/primitives/messages/src/lib.rs

@@ -20,9 +20,15 @@
 // RuntimeApi generated functions
 #![allow(clippy::too_many_arguments)]
 
-use bp_runtime::{BasicOperatingMode, OperatingMode, RangeInclusiveExt};
+use bp_header_chain::HeaderChainError;
+use bp_runtime::{
+	messages::MessageDispatchResult, BasicOperatingMode, OperatingMode, RangeInclusiveExt,
+	StorageProofError,
+};
 use codec::{Decode, Encode, MaxEncodedLen};
-use frame_support::RuntimeDebug;
+use frame_support::{PalletError, RuntimeDebug};
+// Weight is reexported to avoid additional frame-support dependencies in related crates.
+pub use frame_support::weights::Weight;
 use scale_info::TypeInfo;
 use source_chain::RelayersRewards;
 use sp_core::TypeId;
@@ -32,10 +38,6 @@ pub mod source_chain;
 pub mod storage_keys;
 pub mod target_chain;
 
-use bp_runtime::messages::MessageDispatchResult;
-// Weight is reexported to avoid additional frame-support dependencies in related crates.
-pub use frame_support::weights::Weight;
-
 /// Messages pallet operating mode.
 #[derive(Encode, Decode, Clone, Copy, PartialEq, Eq, RuntimeDebug, TypeInfo, MaxEncodedLen)]
 #[cfg_attr(feature = "std", derive(serde::Serialize, serde::Deserialize))]
@@ -414,6 +416,31 @@ pub enum BridgeMessagesCall<AccountId, MessagesProof, MessagesDeliveryProof> {
 	},
 }
 
+/// Error that happens during message verification.
+#[derive(Encode, Decode, RuntimeDebug, PartialEq, Eq, PalletError, TypeInfo)]
+pub enum VerificationError {
+	/// The message proof is empty.
+	EmptyMessageProof,
+	/// Error returned by the bridged header chain.
+	HeaderChain(HeaderChainError),
+	/// Error returned while reading/decoding inbound lane data from the storage proof.
+	InboundLaneStorage(StorageProofError),
+	/// The declared message weight is incorrect.
+	InvalidMessageWeight,
+	/// Declared messages count doesn't match actual value.
+	MessagesCountMismatch,
+	/// Error returned while reading/decoding message data from the storage proof.
+	MessageStorage(StorageProofError),
+	/// The message is too large.
+	MessageTooLarge,
+	/// Error returned while reading/decoding outbound lane data from the storage proof.
+	OutboundLaneStorage(StorageProofError),
+	/// Storage proof related error.
+	StorageProof(StorageProofError),
+	/// Custom error
+	Other(#[codec(skip)] &'static str),
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;