added some better error handling (#31)

README.md

@@ -76,8 +76,12 @@ Below is a list of the error codes that can be seen in the json output of the cl
 - 12 => `FailedToCallRPC`
 - 13 => `VerificationKeyHashMismatch`
 - 14 => `FailedToDownloadVerificationKey`
-- 15=> `FailedToWriteVerificationKeyToDisk`
+- 15 => `FailedToWriteVerificationKeyToDisk`
 - 16 => `ProofVerificationFailed`
+- 17 => `FailedToLoadVerificationKey`,
+- 18 => `BadCalldataLength`,
+- 19 => `FailedToCallRPCJsonError`,
+- 20 => `FailedToCallRPCResponseError`,
 
 # Future plans
 

src/block_header.rs

@@ -36,6 +36,10 @@ impl BlockAuxilaryOutput {
 pub fn parse_aux_data(func: &Function, calldata: &[u8]) -> Result<BlockAuxilaryOutput, StatusCode> {
     use ethers::abi;
 
+    if calldata.len() < 5 {
+        return Err(StatusCode::BadCalldataLength);
+    }
+
     let mut parsed_calldata = func.decode_input(&calldata[4..]).unwrap();
     assert_eq!(parsed_calldata.len(), 2);
 

src/outputs.rs

@@ -28,6 +28,10 @@ pub enum StatusCode {
     FailedToDownloadVerificationKey,
     FailedToWriteVerificationKeyToDisk,
     ProofVerificationFailed,
+    FailedToLoadVerificationKey,
+    BadCalldataLength,
+    FailedToCallRPCJsonError,
+    FailedToCallRPCResponseError,
 }
 
 #[derive(Default)]

src/requests.rs

@@ -69,7 +69,7 @@ pub async fn fetch_l1_data(
 ) -> Result<L1BatchAndProofData, StatusCode> {
     let commit_data = fetch_l1_commit_data(batch_number, network, rpc_url).await;
     if commit_data.is_err() {
-        return Err(StatusCode::FailedToGetDataFromL1);
+        return Err(commit_data.err().unwrap());
     }
 
     let (batch_l1_data, aux_output) = commit_data.unwrap();
@@ -112,8 +112,7 @@ pub async fn fetch_l1_commit_data(
     let mut curr_batch_commitment = H256::default();
     for b_number in [previous_batch_number, batch_number] {
         let commit_tx = fetch_batch_commit_tx(b_number, network)
-            .await
-            .map_err(|_| StatusCode::FailedToFindCommitTxn);
+            .await;
 
         if commit_tx.is_err() {
             return Err(commit_tx.err().unwrap());
@@ -363,14 +362,14 @@ pub async fn fetch_batch_commit_tx(
             .await;
 
         if json.is_err() {
-            return Err(StatusCode::FailedToCallRPC);
+            return Err(StatusCode::FailedToCallRPCJsonError);
         }
 
         let json = json.unwrap();
 
         return Ok((json.result.commitTxHash, json.result.proveTxHash));
     } else {
-        return Err(StatusCode::FailedToCallRPC);
+        return Err(StatusCode::FailedToCallRPCResponseError);
     }
 }
 
@@ -381,6 +380,10 @@ fn find_state_data_from_log(
 ) -> Result<Option<(u64, Vec<u8>)>, StatusCode> {
     use ethers::abi;
 
+    if calldata.len() < 5 {
+        return Err(StatusCode::BadCalldataLength);
+    }
+
     let mut parsed_input = function.decode_input(&calldata[4..]).unwrap();
     assert_eq!(parsed_input.len(), 2);
     let second_param = parsed_input.pop().unwrap();

src/snark_wrapper_verifier.rs

@@ -80,9 +80,16 @@ pub async fn verify_snark(
     );
 
     println!("=== Loading verification key.");
+    let verification_key = &fs::read_to_string(snark_vk_scheduler_key_file.clone());
+
+    if verification_key.is_err() {
+        println!("Unable to load verification key from: {}", snark_vk_scheduler_key_file.clone());
+        return Err(StatusCode::FailedToLoadVerificationKey);
+    }
+
     use circuit_definitions::snark_wrapper::franklin_crypto::bellman::plonk::better_better_cs::verifier::verify;
     let vk_inner : VerificationKey<Bn256, ZkSyncSnarkWrapperCircuit> = serde_json::from_str(
-        &fs::read_to_string(snark_vk_scheduler_key_file.clone()).unwrap()
+        &verification_key.as_ref().unwrap()
     )
     .unwrap();