feat: custom block import stage that verifies Sierra -> CASM class in…

…tegrity for declare transactions (#1530)

CHANGELOG.md

@@ -34,6 +34,9 @@
 - chore(db): changed the way hashes are encoded
 - refacto: reusable Eth client config for settlement/DA/other tasks
 - ci: add gomu gomu no gatling perfomrance test
+- feat(runtime): moved StarkEvents from Substrate events to runtime storage
+- feat(node): validate declare txs against local Sierra class in block import
+  queue
 - feat(runtime): moved StarkEvents from Substrate
 - feat(rpc/trace_api): add `trace_transaction`
 - fix(docker): fix dockerfile for `madara-node`

Cargo.toml

@@ -26,6 +26,7 @@ members = [
   "crates/client/commitment-state-diff",
   "crates/client/settlement",
   "crates/client/eth-client",
+  "crates/client/starknet-block-import",
   "starknet-rpc-test",
   "da-test",
   "starknet-e2e-test",
@@ -59,6 +60,7 @@ default-members = [
   "crates/client/commitment-state-diff",
   "crates/client/settlement",
   "crates/client/eth-client",
+  "crates/client/starknet-block-import",
   "starknet-test-utils",
 ]
 
@@ -190,6 +192,7 @@ mc-commitment-state-diff = { path = "crates/client/commitment-state-diff" }
 mc-l1-messages = { path = "crates/client/l1-messages" }
 mc-settlement = { path = "crates/client/settlement" }
 mc-eth-client = { path = "crates/client/eth-client" }
+mc-starknet-block-import = { path = "crates/client/starknet-block-import" }
 
 # Madara runtime
 madara-runtime = { path = "crates/runtime" }

crates/client/db/src/lib.rs

@@ -21,7 +21,7 @@ use starknet_api::hash::StarkHash;
 mod da_db;
 mod db_opening_utils;
 mod messaging_db;
-mod sierra_classes_db;
+pub mod sierra_classes_db;
 pub use messaging_db::LastSyncedEventBlock;
 mod l1_handler_tx_fee;
 mod meta_db;

crates/client/starknet-block-import/Cargo.toml

@@ -0,0 +1,52 @@
+[package]
+name = "mc-starknet-block-import"
+version.workspace = true
+edition.workspace = true
+description = "Starknet specific block import logic"
+homepage = "https://github.com/keep-starknet-strange/madara"
+license = "MIT"
+publish = false
+repository = "https://github.com/keep-starknet-strange/madara"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+async-trait = "0.1"
+log = { workspace = true }
+num-bigint = { workspace = true }
+thiserror = { workspace = true }
+
+# Substrate primitives dependencies
+sp-api = { workspace = true }
+sp-consensus = { workspace = true }
+sp-runtime = { workspace = true }
+
+# Substrate client dependencies
+sc-consensus = { workspace = true }
+sc-rpc-api = { workspace = true }
+
+# Starknet
+blockifier = { workspace = true }
+cairo-lang-starknet = { workspace = true }
+cairo-lang-starknet-classes = { workspace = true }
+cairo-lang-utils = { workspace = true }
+cairo-vm = { workspace = true }
+hex = { workspace = true }
+madara-runtime = { workspace = true }
+mc-db = { workspace = true }
+mc-rpc = { workspace = true }
+pallet-starknet = { workspace = true }
+pallet-starknet-runtime-api = { workspace = true }
+starknet-core = { workspace = true }
+starknet_api = { workspace = true, features = [
+  "scale-info",
+  "parity-scale-codec",
+] }
+
+# Primitives
+mp-felt = { workspace = true }
+mp-transactions = { workspace = true, features = ["scale-info"] }
+
+[dev-dependencies]
+serde_json = { workspace = true }

crates/client/starknet-block-import/README.md

@@ -0,0 +1,50 @@
+# Starknet block import
+
+This crate introduces a Starknet specific handler that can be added to the block
+import pipeline. More specifically, it "wraps" the underlying block import logic
+i.e. executes first in the queue.
+
+Read more about block import pipeline:
+
+- <https://docs.substrate.io/learn/transaction-lifecycle/#block-authoring-and-block-imports>
+- <https://doc.deepernetwork.org/v3/advanced/block-import/>
+
+The purpose of this custom block import logic is to do additional checks for
+declare transactions. Despite the introduction of the safe intermediate
+representation (Sierra) for Cairo, there's still a possibility of the following
+attack:
+
+- User crafts a malicious Cairo contract the execution of which cannot be proven
+- User submits that transaction via a patched node that does not verify Sierra
+  classes
+- The runtime does not have Sierra classes and therefore cannot check the
+  validiy either
+- Sequencer fails to prove the execution and also cannot charge for the work
+  done => DoS attack vector
+
+Read more about Sierra and the problem it addresses:
+
+- <https://docs.starknet.io/documentation/architecture_and_concepts/Smart_Contracts/cairo-and-sierra/>
+
+Starknet block import solves the issue above as follows:
+
+- Upon receiving a new block it searches for declare transactions
+- For every declare transaction found, it tries to find according Sierra classes
+  in the local DB
+- It tries to compile the class to check if they match the contract class from
+  the transaction
+- The block import fails if there is at least one transaction with mismatching
+  class hashes
+
+## Notes
+
+Currently Sierra classes DB is populated when user submits RPC requests and
+therefore the approch works for single node setup only. In order to make it work
+in the multi-node setting, one needs to query missing Sierra classes from other
+nodes via P2P (see
+<https://github.com/starknet-io/starknet-p2p-specs/blob/main/p2p/proto/class.proto>)
+
+Cairo compiler version mismatch can be a problem, e.g. if the version used by
+Madara is lagging behind significantly it can fail to compile Sierra classes
+obtained from the recent compilers. Similarly, old Sierra classes might not
+compile because of the broken backward compatibility.