fix: prevent creating Section with elders info signed with wrong key

examples/stress.rs

@@ -439,17 +439,23 @@ impl Network {
             return Ok(false);
         };
 
+        // There can be a significant delay between a node being relocated and us receiving the
+        // `Relocated` event. Using the current node name instead of the one reported by the last
+        // `Relocated` event reduced send errors due to src location mismatch which would cause the
+        // section health to appear lower than it actually is.
+        let src = node.name().await;
+
         // The message dst is unique so we use it also as its indentifier.
         let bytes = bincode::serialize(&dst)?;
         let signature_share = node
             .sign_as_elder(&bytes, &public_key_set.public_key())
             .await
-            .context("failed to sign probe")?;
+            .with_context(|| format!("failed to sign probe by {}", src))?;
 
         let index = node
             .our_index()
             .await
-            .context("failed to retrieve key share index")?;
+            .with_context(|| format!("failed to retrieve key share index by {}", src))?;
 
         let message = ProbeMessage {
             proof_share: ProofShare {
@@ -460,12 +466,6 @@ impl Network {
         };
         let bytes = bincode::serialize(&message)?.into();
 
-        // There can be a significant delay between a node being relocated and us receiving the
-        // `Relocated` event. Using the current node name instead of the one reported by the last
-        // `Relocated` event reduced send errors due to src location mismatch which would cause the
-        // section health to appear lower than it actually is.
-        let src = node.name().await;
-
         let itinerary = Itinerary {
             src: SrcLocation::Node(src),
             dst: DstLocation::Section(dst),
@@ -475,7 +475,9 @@ impl Network {
         match node.send_message(itinerary, bytes).await {
             Ok(()) => Ok(true),
             Err(RoutingError::InvalidSrcLocation) => Ok(false), // node name changed
-            Err(error) => Err(Error::from(error).context("failed to send probe")),
+            Err(error) => {
+                Err(Error::from(error).context(format!("failed to send probe by {}", src)))
+            }
         }
     }
 

src/routing/tests/mod.rs

@@ -1030,7 +1030,7 @@ async fn handle_bounced_unknown_message() -> Result<()> {
     let mut section_chain = SectionChain::new(pk0);
     let _ = section_chain.insert(&pk0, pk1, pk1_signature);
 
-    let proven_elders_info = proven(&sk0, elders_info)?;
+    let proven_elders_info = proven(sk1_set.secret_key(), elders_info)?;
     let section = Section::new(section_chain, proven_elders_info)?;
     let section_key_share = create_section_key_share(&sk1_set, 0);
 
@@ -1123,7 +1123,7 @@ async fn handle_bounced_untrusted_message() -> Result<()> {
     let mut chain = SectionChain::new(pk0);
     let _ = chain.insert(&pk0, pk1, pk1_signature);
 
-    let proven_elders_info = proven(&sk0, elders_info)?;
+    let proven_elders_info = proven(sk1_set.secret_key(), elders_info)?;
     let section = Section::new(chain.clone(), proven_elders_info)?;
     let section_key_share = create_section_key_share(&sk1_set, 0);
 
@@ -1213,7 +1213,7 @@ async fn handle_sync() -> Result<()> {
     assert_eq!(chain.insert(&pk0, pk1, pk1_signature), Ok(()));
 
     let (old_elders_info, mut nodes) = create_elders_info();
-    let proven_old_elders_info = proven(&sk0, old_elders_info.clone())?;
+    let proven_old_elders_info = proven(sk1_set.secret_key(), old_elders_info.clone())?;
     let old_section = Section::new(chain.clone(), proven_old_elders_info)?;
 
     // Create our node
@@ -1374,7 +1374,7 @@ async fn handle_bounced_untrusted_sync() -> Result<()> {
     chain.insert(&pk1, pk2, sig2)?;
 
     let (elders_info, mut nodes) = create_elders_info();
-    let proven_elders_info = proven(&sk0, elders_info.clone())?;
+    let proven_elders_info = proven(sk2, elders_info.clone())?;
     let section_full = Section::new(chain, proven_elders_info)?;
     let section_trimmed = section_full.trimmed(2);
 

src/section/mod.rs

@@ -43,8 +43,11 @@ pub(crate) struct Section {
 impl Section {
     /// Creates a minimal `Section` initially containing only info about our elders
     /// (`elders_info`).
+    ///
+    /// Returns error if `elders_info` is not signed with the last key of `chain`.
     pub fn new(chain: SectionChain, elders_info: Proven<EldersInfo>) -> Result<Self, Error> {
-        if !chain.has_key(&elders_info.proof.public_key) {
+        if elders_info.proof.public_key != *chain.last_key() {
+            error!("can't create section: elders_info signed with incorrect key");
             // TODO: consider more specific error here.
             return Err(Error::InvalidMessage);
         }