Reset the state after processing the transaction

Author: Lbqds

app/src/handler.rs

@@ -107,7 +107,13 @@ pub fn handle_apdu(
             }
         }
         Ins::SignTx => {
-            let data = comm.get_data()?;
+            let data = match comm.get_data() {
+                Ok(data) => data,
+                Err(code) => {
+                    reset(sign_tx_context, tx_reviewer);
+                    return Err(code.into());
+                }
+            };
             match handle_sign_tx(apdu_header, data, sign_tx_context, tx_reviewer) {
                 Ok(()) if !sign_tx_context.is_complete() => {
                     return Ok(());
@@ -125,9 +131,11 @@ pub fn handle_apdu(
                         }
                         Err(code) => Err(code.into()),
                     };
+                    reset(sign_tx_context, tx_reviewer);
                     return result;
                 }
                 Err(code) => {
+                    reset(sign_tx_context, tx_reviewer);
                     return Err(code.into());
                 }
             }
@@ -158,11 +166,6 @@ fn handle_sign_tx(
             let token_size = data[0]; // the first byte is the token size
             check_token_size(token_size)?;
             tx_reviewer.init(token_size)?;
-
-            // we check whether the tx is completed after processing each data frame
-            // so we need to call `reset` to reset the status of the previous tx
-            // we will initialize the `sign_tx_context` upon receiving the first tx data frame
-            sign_tx_context.reset();
             if token_size == 0 {
                 return Ok(());
             }
@@ -198,3 +201,9 @@ fn check_token_size(size: u8) -> Result<(), ErrorCode> {
         Ok(())
     }
 }
+
+#[inline]
+fn reset(sign_tx_context: &mut SignTxContext, tx_reviewer: &mut TxReviewer) {
+    sign_tx_context.reset();
+    tx_reviewer.reset();
+}

app/src/sign_tx_context.rs

@@ -61,7 +61,12 @@ impl SignTxContext {
     }
 
     pub fn reset(&mut self) {
+        self.path = [0; PATH_LENGTH];
+        self.tx_decoder.reset();
         self.current_step = DecodeStep::Init;
+        self.hasher.reset();
+        self.temp_data.reset(0);
+        self.device_address = None;
     }
 
     pub fn is_complete(&self) -> bool {

app/src/ui/tx_reviewer.rs

@@ -79,6 +79,16 @@ impl TxReviewer {
         Ok(())
     }
 
+    pub fn reset(&mut self) {
+        self.reset_buffer(0);
+        self.has_external_inputs = false;
+        self.next_output_index = FIRST_OUTPUT_INDEX;
+        self.tx_fee = None;
+        self.is_tx_execute_script = false;
+        self.token_metadata_length = 0;
+        self.token_verifier = None;
+    }
+
     pub fn handle_token_metadata(&mut self, data: &[u8]) -> Result<(), ErrorCode> {
         assert!(self.token_verifier.is_none());
         let token_verifier = TokenVerifier::new(data)?;