From dc1c0404d0a5dcd0acf79a0e9d4cdc95bcf9afc2 Mon Sep 17 00:00:00 2001
From: Kevin Wang <wy721@qq.com>
Date: Sun, 18 Feb 2024 03:18:01 +0000
Subject: [PATCH] Use constants and remove unnecessary check

---
 crates/phactory/src/nts.rs          |  6 ++++--
 crates/phactory/src/prpc_service.rs | 14 ++++++--------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/crates/phactory/src/nts.rs b/crates/phactory/src/nts.rs
index 2f2fe8a8f..9d0c42f4f 100644
--- a/crates/phactory/src/nts.rs
+++ b/crates/phactory/src/nts.rs
@@ -32,7 +32,9 @@ pub(crate) async fn nts_get_time_secs() -> Result<u64> {
 }
 
 fn validate_results(results: Vec<u64>) -> Result<u64> {
-    if results.len() < 2 {
+    const MIN_RESULTS: usize = 2;
+    const MAX_VARIANCE: u64 = 60;
+    if results.len() < MIN_RESULTS {
         anyhow::bail!("Not enough results");
     }
     let average = results.iter().sum::<u64>() / results.len() as u64;
@@ -41,7 +43,7 @@ fn validate_results(results: Vec<u64>) -> Result<u64> {
         .map(|r| (*r as i64 - average as i64).unsigned_abs())
         .max()
         .unwrap_or_default();
-    if max_diff > 60 {
+    if max_diff > MAX_VARIANCE {
         anyhow::bail!("Time difference is too large: {}", max_diff);
     }
     Ok(average)
diff --git a/crates/phactory/src/prpc_service.rs b/crates/phactory/src/prpc_service.rs
index 234c884cb..7f14669b9 100644
--- a/crates/phactory/src/prpc_service.rs
+++ b/crates/phactory/src/prpc_service.rs
@@ -1866,6 +1866,8 @@ impl<Platform: pal::Platform + Serialize + DeserializeOwned> PhactoryApi for Rpc
         &mut self,
         request: pb::DcapHandoverChallengeResponse,
     ) -> RpcResult<pb::DcapHandoverWorkerKey> {
+        const CLIENT_TIMEOUT_SECS: u64 = 60;
+
         let ntp_now = crate::nts::nts_get_time_secs()
             .await
             .map_err(from_display)?;
@@ -1884,7 +1886,9 @@ impl<Platform: pal::Platform + Serialize + DeserializeOwned> PhactoryApi for Rpc
             return Err(from_display("Invalid challenge"));
         }
         // 2. ensure delta time between client and server is within 1 minutes
-        if challenge.ntp_time_secs > ntp_now || ntp_now - challenge.ntp_time_secs > 60 {
+        if challenge.ntp_time_secs > ntp_now
+            || ntp_now - challenge.ntp_time_secs > CLIENT_TIMEOUT_SECS
+        {
             return Err(from_display("Invalid NTP time"));
         }
         // 3. verify sgx local attestation report to ensure the handover pRuntimes are on the same machine
@@ -1897,13 +1901,7 @@ impl<Platform: pal::Platform + Serialize + DeserializeOwned> PhactoryApi for Rpc
         if handler_hash != recv_local_report.body.report_data[..32] {
             return Err(from_display("Invalid challenge handler"));
         }
-        // 4. verify challenge block height and report timestamp
-        // only challenge within 150 blocks (30 minutes) is accepted
-        let challenge_height = challenge.block_number;
-        if !(challenge_height <= block_number && block_number - challenge_height <= 150) {
-            return Err(from_display("Outdated challenge"));
-        }
-        // 5. verify pruntime launch date, never handover to old pruntime
+        // 4. verify pruntime launch date, never handover to old pruntime
         if !dev_mode {
             let runtime_state = phactory.runtime_state()?;
             let my_runtime_timestamp = runtime_state