Only allow designated participants to send transactions

coordinator/tributary/src/tests/blockchain.rs

@@ -12,19 +12,25 @@ use crate::{
   tests::{ProvidedTransaction, SignedTransaction, random_provided_transaction},
 };
 
-fn new_blockchain<T: Transaction>() -> ([u8; 32], Blockchain<T>) {
+fn new_genesis() -> [u8; 32] {
   let mut genesis = [0; 32];
   OsRng.fill_bytes(&mut genesis);
+  genesis
+}
 
-  let blockchain = Blockchain::new(genesis);
+fn new_blockchain<T: Transaction>(
+  genesis: [u8; 32],
+  participants: &[<Ristretto as Ciphersuite>::G],
+) -> Blockchain<T> {
+  let blockchain = Blockchain::new(genesis, participants);
   assert_eq!(blockchain.tip(), genesis);
-
-  (genesis, blockchain)
+  blockchain
 }
 
 #[test]
 fn block_addition() {
-  let (genesis, mut blockchain) = new_blockchain::<SignedTransaction>();
+  let genesis = new_genesis();
+  let mut blockchain = new_blockchain::<SignedTransaction>(genesis, &[]);
   let block = blockchain.build_block(HashMap::new());
   assert_eq!(block.header.parent, genesis);
   assert_eq!(block.header.transactions, [0; 32]);
@@ -35,7 +41,8 @@ fn block_addition() {
 
 #[test]
 fn invalid_block() {
-  let (genesis, blockchain) = new_blockchain::<SignedTransaction>();
+  let genesis = new_genesis();
+  let blockchain = new_blockchain::<SignedTransaction>(genesis, &[]);
 
   let block = blockchain.build_block(HashMap::new());
 
@@ -55,10 +62,36 @@ fn invalid_block() {
   }
 
   let key = Zeroizing::new(<Ristretto as Ciphersuite>::F::random(&mut OsRng));
+  let tx = crate::tests::signed_transaction(&mut OsRng, genesis, &key, 0);
+
+  // Not a participant
+  {
+    // Manually create the block to bypass build_block's checks
+    let block = Block::new(
+      blockchain.tip(),
+      &ProvidedTransactions::new(),
+      HashMap::from([(tx.hash(), tx.clone())]),
+    );
+    assert_eq!(block.header.transactions, merkle(&[tx.hash()]));
+    assert!(blockchain.verify_block(&block).is_err());
+  }
+
+  // Run the rest of the tests with them as a participant
+  let blockchain = new_blockchain(genesis, &[tx.1.signer]);
+
+  // Re-run the not a participant block to make sure it now works
+  {
+    let block = Block::new(
+      blockchain.tip(),
+      &ProvidedTransactions::new(),
+      HashMap::from([(tx.hash(), tx.clone())]),
+    );
+    assert_eq!(block.header.transactions, merkle(&[tx.hash()]));
+    blockchain.verify_block(&block).unwrap();
+  }
 
   {
     // Add a valid transaction
-    let tx = crate::tests::signed_transaction(&mut OsRng, genesis, &key, 0);
     let mut block = blockchain.build_block(HashMap::from([(tx.hash(), tx.clone())]));
     assert_eq!(block.header.transactions, merkle(&[tx.hash()]));
     blockchain.verify_block(&block).unwrap();
@@ -79,7 +112,6 @@ fn invalid_block() {
 
   {
     // Invalid signature
-    let tx = crate::tests::signed_transaction(&mut OsRng, genesis, &key, 0);
     let mut block = blockchain.build_block(HashMap::from([(tx.hash(), tx)]));
     blockchain.verify_block(&block).unwrap();
     block.transactions[0].1.signature.s += <Ristretto as Ciphersuite>::F::ONE;
@@ -93,11 +125,14 @@ fn invalid_block() {
 
 #[test]
 fn signed_transaction() {
-  let (genesis, mut blockchain) = new_blockchain::<SignedTransaction>();
+  let genesis = new_genesis();
+
   let key = Zeroizing::new(<Ristretto as Ciphersuite>::F::random(&mut OsRng));
   let tx = crate::tests::signed_transaction(&mut OsRng, genesis, &key, 0);
   let signer = tx.1.signer;
-  assert_eq!(blockchain.next_nonce(signer), 0);
+
+  let mut blockchain = new_blockchain::<SignedTransaction>(genesis, &[signer]);
+  assert_eq!(blockchain.next_nonce(signer), Some(0));
 
   let test = |blockchain: &mut Blockchain<SignedTransaction>, mempool: HashMap<_, _>| {
     let mut hashes = mempool.keys().cloned().collect::<HashSet<_>>();
@@ -126,7 +161,7 @@ fn signed_transaction() {
 
   // Test with a single nonce
   test(&mut blockchain, HashMap::from([(tx.hash(), tx)]));
-  assert_eq!(blockchain.next_nonce(signer), 1);
+  assert_eq!(blockchain.next_nonce(signer), Some(1));
 
   // Test with a flood of nonces
   let mut mempool = HashMap::new();
@@ -140,12 +175,12 @@ fn signed_transaction() {
     mempool.insert(tx.hash(), tx);
   }
   test(&mut blockchain, mempool);
-  assert_eq!(blockchain.next_nonce(signer), 64);
+  assert_eq!(blockchain.next_nonce(signer), Some(64));
 }
 
 #[test]
 fn provided_transaction() {
-  let (_, mut blockchain) = new_blockchain::<ProvidedTransaction>();
+  let mut blockchain = new_blockchain::<ProvidedTransaction>(new_genesis(), &[]);
 
   let tx = random_provided_transaction(&mut OsRng);
   let mut txs = ProvidedTransactions::new();