From 910f8874ac377a118796a23811bf98a929a6e0c9 Mon Sep 17 00:00:00 2001
From: Jesse Schulman <jesse@caleos.io>
Date: Sat, 28 Sep 2024 16:24:51 -0700
Subject: [PATCH 1/2] Allow trailing zero values in RLP decoding

---
 translator/src/rlp/telos_rlp_decode.rs | 14 +++++++++----
 translator/tests/rlp.rs                | 29 +++++++++++++++++++++++++-
 2 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/translator/src/rlp/telos_rlp_decode.rs b/translator/src/rlp/telos_rlp_decode.rs
index f9f4881..ad52456 100644
--- a/translator/src/rlp/telos_rlp_decode.rs
+++ b/translator/src/rlp/telos_rlp_decode.rs
@@ -4,6 +4,7 @@ use alloy_consensus::{SignableTransaction, Signed, TxLegacy};
 
 use alloy_rlp::Result;
 use bytes::Buf;
+use tracing::error;
 
 fn decode_fields(data: &mut &[u8]) -> Result<TxLegacy, Error> {
     let nonce = u64::decode(data).map_err(|_| Error::Custom("Failed to decode nonce"))?;
@@ -88,10 +89,15 @@ impl TelosTxDecodable for TxLegacy {
 
         let signed = tx.into_signed(sig);
         if buf.len() + header.payload_length != original_len {
-            return Err(Error::ListLengthMismatch {
-                expected: header.payload_length,
-                got: original_len - buf.len(),
-            });
+            for b in buf.iter() {
+                if *b != 128 {
+                    error!("Transaction has trailing non-zero RLP values: {:?}", signed);
+                    return Err(Error::ListLengthMismatch {
+                        expected: header.payload_length,
+                        got: original_len - buf.len(),
+                    });
+                }
+            }
         }
 
         Ok(signed)
diff --git a/translator/tests/rlp.rs b/translator/tests/rlp.rs
index e4b1d9a..81eab35 100644
--- a/translator/tests/rlp.rs
+++ b/translator/tests/rlp.rs
@@ -1,10 +1,12 @@
 use alloy::hex;
 use alloy::hex::FromHex;
-use alloy::primitives::{Address, B256};
+use alloy::primitives::{Address, Signature, B256, U256};
 use alloy_consensus::TxLegacy;
 use antelope::chain::checksum::Checksum256;
+use std::str::FromStr;
 use telos_translator_rs::rlp::telos_rlp_decode::TelosTxDecodable;
 use telos_translator_rs::transaction::make_unique_vrs;
+use tracing::info;
 
 #[test]
 fn test_unsigned_trx() {
@@ -80,3 +82,28 @@ fn test_signed_trx() {
 
     assert!(signed_legacy.is_ok());
 }
+
+#[tokio::test]
+async fn test_trailing_empty_values() {
+    // this buffer has trailing empty RLP values, which have been accepted on chain
+    //   and so we need to handle them
+    let byte_array: [u8; 43] = [
+        234, 21, 133, 117, 98, 209, 251, 63, 131, 30, 132, 128, 148, 221, 124, 155, 23, 110, 221,
+        57, 225, 22, 88, 115, 0, 111, 245, 56, 10, 44, 0, 51, 174, 130, 39, 16, 130, 0, 0, 128,
+        128, 128, 128,
+    ];
+    let mut slice: &[u8] = &byte_array;
+    let buf = &mut slice;
+    let r = U256::from_str(
+        "7478307613393818857995123362551696556625819847066981460737539381080402549198",
+    )
+    .unwrap();
+    let s = U256::from_str(
+        "93208746529385687702128536437164864077231874732405909428462768306792425324544",
+    )
+    .unwrap();
+    let v = 42u64;
+    let sig = Signature::from_rs_and_parity(r, s, v);
+    TxLegacy::decode_telos_signed_fields(buf, Some(sig.unwrap())).unwrap();
+    info!("Passed!");
+}

From 824118f9a3fc1654acf73bf45ba3ff0566b2c445 Mon Sep 17 00:00:00 2001
From: Jesse Schulman <jesse@caleos.io>
Date: Sun, 29 Sep 2024 23:10:25 -0700
Subject: [PATCH 2/2] Better logic for zero values check

---
 translator/src/rlp/telos_rlp_decode.rs | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/translator/src/rlp/telos_rlp_decode.rs b/translator/src/rlp/telos_rlp_decode.rs
index ad52456..21d5dde 100644
--- a/translator/src/rlp/telos_rlp_decode.rs
+++ b/translator/src/rlp/telos_rlp_decode.rs
@@ -88,19 +88,15 @@ impl TelosTxDecodable for TxLegacy {
         tx.chain_id = sig.v().chain_id();
 
         let signed = tx.into_signed(sig);
-        if buf.len() + header.payload_length != original_len {
-            for b in buf.iter() {
-                if *b != 128 {
-                    error!("Transaction has trailing non-zero RLP values: {:?}", signed);
-                    return Err(Error::ListLengthMismatch {
-                        expected: header.payload_length,
-                        got: original_len - buf.len(),
-                    });
-                }
-            }
+        if buf.len() + header.payload_length == original_len || buf.iter().all(|&b| b == 128) {
+            return Ok(signed);
         }
 
-        Ok(signed)
+        error!("Transaction has trailing non-zero RLP values: {:?}", signed);
+        Err(Error::ListLengthMismatch {
+            expected: header.payload_length,
+            got: original_len - buf.len(),
+        })
     }
 }