Merge pull request #1145 from doitian/fix-977-cch-btc-expiry-overflow

fix: handle overflow in BTC final TLC expiry delta calculation

Author: quake

crates/fiber-lib/src/cch/actor.rs

@@ -33,6 +33,9 @@ use crate::time::{Duration, SystemTime, UNIX_EPOCH};
 pub const ACTION_RETRY_BASE_MILLIS: u64 = 1000; // 1 second initial delay
 pub const ACTION_RETRY_MAX_MILLIS: u64 = 600_000; // 10 minute max delay
 
+/// Average time per Bitcoin block in milliseconds (10 minutes = 600 seconds = 600,000 ms).
+pub const BTC_BLOCK_TIME_MILLIS: u64 = 600_000;
+
 fn calculate_retry_delay(retry_count: u32) -> Duration {
     // Exponential backoff starting from ACTION_RETRY_BASE_MILLIS, capped at ACTION_RETRY_MAX_MILLIS
     let max_shift = (ACTION_RETRY_MAX_MILLIS / ACTION_RETRY_BASE_MILLIS).ilog2();
@@ -560,7 +563,16 @@ impl<S: CchOrderStore> CchState<S> {
             .final_tlc_minimum_expiry_delta()
             .copied()
             .unwrap_or(0);
-        let btc_final_cltv_millis = self.config.btc_final_tlc_expiry_delta_blocks * 600 * 1000;
+        let btc_final_cltv_millis = self
+            .config
+            .btc_final_tlc_expiry_delta_blocks
+            .checked_mul(BTC_BLOCK_TIME_MILLIS)
+            .ok_or_else(|| {
+                CchError::ConfigError(format!(
+                    "btc_final_tlc_expiry_delta_blocks ({}) is too large and causes overflow when converting to milliseconds",
+                    self.config.btc_final_tlc_expiry_delta_blocks
+                ))
+            })?;
         if ckb_final_tlc_millis >= btc_final_cltv_millis / 2 {
             return Err(CchError::CKBInvoiceFinalTlcExpiryDeltaTooLarge);
         }

crates/fiber-lib/src/cch/error.rs

@@ -14,6 +14,8 @@ pub enum CchStoreError {
 
 #[derive(Error, Debug)]
 pub enum CchError {
+    #[error("Configuration error: {0}")]
+    ConfigError(String),
     #[error("Store error: {0}")]
     StoreError(#[from] CchStoreError),
     #[error("Outgoing invoice expiry time is too short")]