Removes Snowbridge parachain directory (#3186)

Removes the `bridges/snowbridge/parachain` directory and moves
everything up to under `snowbridge` directly. We are cleaning up our
local dev env after merging our crates into the polkadot-sdk.

---------

Co-authored-by: claravanstaden <Cats 4 life!>

bridges/snowbridge/pallets/ethereum-client/src/impls.rs

@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use super::*;
+
+use snowbridge_core::inbound::{
+	VerificationError::{self, *},
+	*,
+};
+use snowbridge_ethereum::Receipt;
+
+impl<T: Config> Verifier for Pallet<T> {
+	/// Verify a message by verifying the existence of the corresponding
+	/// Ethereum log in a block. Returns the log if successful. The execution header containing
+	/// the log should be in the beacon client storage, meaning it has been verified and is an
+	/// ancestor of a finalized beacon block.
+	fn verify(event_log: &Log, proof: &Proof) -> Result<(), VerificationError> {
+		log::info!(
+			target: "ethereum-client",
+			"💫 Verifying message with block hash {}",
+			proof.block_hash,
+		);
+
+		let header = <ExecutionHeaderBuffer<T>>::get(proof.block_hash).ok_or(HeaderNotFound)?;
+
+		let receipt = match Self::verify_receipt_inclusion(header.receipts_root, proof) {
+			Ok(receipt) => receipt,
+			Err(err) => {
+				log::error!(
+					target: "ethereum-client",
+					"💫 Verification of receipt inclusion failed for block {}: {:?}",
+					proof.block_hash,
+					err
+				);
+				return Err(err)
+			},
+		};
+
+		log::trace!(
+			target: "ethereum-client",
+			"💫 Verified receipt inclusion for transaction at index {} in block {}",
+			proof.tx_index, proof.block_hash,
+		);
+
+		event_log.validate().map_err(|_| InvalidLog)?;
+
+		// Convert snowbridge_core::inbound::Log to snowbridge_ethereum::Log.
+		let event_log = snowbridge_ethereum::Log {
+			address: event_log.address,
+			topics: event_log.topics.clone(),
+			data: event_log.data.clone(),
+		};
+
+		if !receipt.contains_log(&event_log) {
+			log::error!(
+				target: "ethereum-client",
+				"💫 Event log not found in receipt for transaction at index {} in block {}",
+				proof.tx_index, proof.block_hash,
+			);
+			return Err(LogNotFound)
+		}
+
+		log::info!(
+			target: "ethereum-client",
+			"💫 Receipt verification successful for {}",
+			proof.block_hash,
+		);
+
+		Ok(())
+	}
+}
+
+impl<T: Config> Pallet<T> {
+	/// Verifies that the receipt encoded in `proof.data` is included in the block given by
+	/// `proof.block_hash`.
+	pub fn verify_receipt_inclusion(
+		receipts_root: H256,
+		proof: &Proof,
+	) -> Result<Receipt, VerificationError> {
+		let result = verify_receipt_proof(receipts_root, &proof.data.1).ok_or(InvalidProof)?;
+
+		match result {
+			Ok(receipt) => Ok(receipt),
+			Err(err) => {
+				log::trace!(
+					target: "ethereum-client",
+					"💫 Failed to decode transaction receipt: {}",
+					err
+				);
+				Err(InvalidProof)
+			},
+		}
+	}
+}