From d23cb42b272f7d12e70cdcc94ab1b056cce773c8 Mon Sep 17 00:00:00 2001
From: Adrien Beraud <adrien.beraud@savoirfairelinux.com>
Date: Sat, 17 Oct 2026 19:37:45 -0400
Subject: [PATCH] tests: cover a peer restarting with the same key

A node restarting with the same key and contacting a peer by address gets answers encrypted with the ephemeral key of its previous run.
---
 tests/test_networkengine.cpp | 27 +++++++++++++++++++++++++++
 tests/test_networkengine.h   |  2 ++
 2 files changed, 29 insertions(+)

diff --git a/tests/test_networkengine.cpp b/tests/test_networkengine.cpp
index ff5be6a0..301a83cb 100644
--- a/tests/test_networkengine.cpp
+++ b/tests/test_networkengine.cpp
@@ -1634,6 +1634,33 @@ NetworkEngineTester::testTransportEphemeralBoundToAddress()
     CPPUNIT_ASSERT_EQUAL((size_t) 1, b.socket->sends.size());
 }
 
+void
+NetworkEngineTester::testTransportRestartedPeerReconnects()
+{
+    TransportConfig configA;
+    configA.key = transport::KeyPair::generate();
+    auto a = std::make_unique<TransportTestNode>("127.0.0.2", configA, 1);
+    TransportTestNode b("127.0.0.3", {}, 2);
+    bool done = false;
+    a->ping(b.addr, done);
+    a->deliverTo(b);
+    b.deliverTo(*a);
+    for (int i = 0; i < 2; i++) {
+        a->ping(a->node(b), done);
+        a->deliverTo(b);
+        b.deliverTo(*a);
+    }
+
+    // a restarts with the same key, and contacts b by address: b must forget a's ephemeral key
+    a = std::make_unique<TransportTestNode>("127.0.0.2", configA, 3);
+    done = false;
+    a->ping(b.addr, done);
+    a->deliverTo(b);
+    CPPUNIT_ASSERT(isEnvelope(b.socket->sends.at(0), transport::EnvelopeType::Initial));
+    b.deliverTo(*a);
+    CPPUNIT_ASSERT(done);
+}
+
 } // namespace test
 
 #endif
\ No newline at end of file
diff --git a/tests/test_networkengine.h b/tests/test_networkengine.h
index 84d443ae..dd43df14 100644
--- a/tests/test_networkengine.h
+++ b/tests/test_networkengine.h
@@ -41,6 +41,7 @@ class NetworkEngineTester : public CppUnit::TestFixture
     CPPUNIT_TEST(testTransportSessionAuthorizesWrites);
     CPPUNIT_TEST(testTransportInitialWriteIsUnauthorized);
     CPPUNIT_TEST(testTransportEphemeralBoundToAddress);
+    CPPUNIT_TEST(testTransportRestartedPeerReconnects);
 #endif
     CPPUNIT_TEST_SUITE_END();
 
@@ -79,6 +80,7 @@ public:
     void testTransportSessionAuthorizesWrites();
     void testTransportInitialWriteIsUnauthorized();
     void testTransportEphemeralBoundToAddress();
+    void testTransportRestartedPeerReconnects();
 #endif
 };