consensus: Reject candidates with txs count higher than MAX_NUMBER_OF…

…_TRANSACTIONS

consensus/Cargo.toml

@@ -43,3 +43,8 @@ serde_json = "1.0"
 serde = { version = "1.0", features = ["derive"] }
 base64 = "0.13"
 node-data = { version = "0.1", path = "../node-data", features = ["faker"]}
+criterion = "0.5"
+
+[[bench]]
+name = "merkle"
+harness = false

consensus/src/commons.rs

@@ -123,6 +123,7 @@ pub enum ConsensusError {
     ChildTaskTerminated,
     Canceled(u64),
     VoteAlreadyCollected,
+    TooManyTransactions(usize),
 }
 
 impl From<StepSigError> for ConsensusError {

consensus/src/config.rs

@@ -26,6 +26,7 @@ pub const RATIFICATION_COMMITTEE_QUORUM: f64 =
 pub const DEFAULT_BLOCK_GAS_LIMIT: u64 = 5 * 1_000_000_000;
 
 pub const RELAX_ITERATION_THRESHOLD: u8 = 8;
+pub const MAX_NUMBER_OF_TRANSACTIONS: usize = 30_000;
 
 /// Emergency mode is enabled after 16 iterations
 pub const EMERGENCY_MODE_ITERATION_THRESHOLD: u8 = 16;

consensus/src/proposal/handler.rs

@@ -5,6 +5,7 @@
 // Copyright (c) DUSK NETWORK. All rights reserved.
 
 use crate::commons::{ConsensusError, Database, RoundUpdate};
+use crate::config::MAX_NUMBER_OF_TRANSACTIONS;
 use crate::merkle::merkle_root;
 use crate::msg_handler::{HandleMsgOutput, MsgHandler};
 use crate::user::committee::Committee;
@@ -95,6 +96,12 @@ impl<D: Database> ProposalHandler<D> {
             return Err(ConsensusError::InvalidBlockHash);
         }
 
+        if p.candidate.txs().len() >= MAX_NUMBER_OF_TRANSACTIONS {
+            return Err(ConsensusError::TooManyTransactions(
+                p.candidate.txs().len(),
+            ));
+        }
+
         let tx_hashes: Vec<_> =
             p.candidate.txs().iter().map(|t| t.hash()).collect();
         let tx_root = merkle_root(&tx_hashes[..]);