Add tests for failed signature validation cases

tests/pubsub/test_pubsub.py

@@ -5,6 +5,7 @@ import pytest
 
 from libp2p.exceptions import ValidationError
 from libp2p.peer.id import ID
+from libp2p.pubsub.pubsub import PUBSUB_SIGNING_PREFIX
 from libp2p.pubsub.pb import rpc_pb2
 from libp2p.tools.pubsub.utils import make_pubsub_msg
 from libp2p.tools.utils import connect
@@ -514,7 +515,7 @@ async def test_push_msg(pubsubs_fsub, monkeypatch):
 
 @pytest.mark.parametrize("num_hosts, is_strict_signing", ((2, True),))
 @pytest.mark.asyncio
-async def test_strict_signing(pubsubs_fsub, hosts, monkeypatch):
+async def test_strict_signing(pubsubs_fsub, hosts):
     await connect(hosts[0], hosts[1])
     await pubsubs_fsub[0].subscribe(TESTING_TOPIC)
     await pubsubs_fsub[1].subscribe(TESTING_TOPIC)
@@ -525,3 +526,57 @@ async def test_strict_signing(pubsubs_fsub, hosts, monkeypatch):
 
     assert len(pubsubs_fsub[0].seen_messages) == 1
     assert len(pubsubs_fsub[1].seen_messages) == 1
+
+
+@pytest.mark.parametrize("num_hosts, is_strict_signing", ((2, True),))
+@pytest.mark.asyncio
+async def test_strict_signing_failed_validation(pubsubs_fsub, hosts, monkeypatch):
+    msg = make_pubsub_msg(
+        origin_id=pubsubs_fsub[0].my_id,
+        topic_ids=[TESTING_TOPIC],
+        data=TESTING_DATA,
+        seqno=b"\x00" * 8,
+    )
+    priv_key = pubsubs_fsub[0].sign_key
+    signature = priv_key.sign(
+        PUBSUB_SIGNING_PREFIX.encode() + msg.SerializeToString()
+    )
+
+    event = asyncio.Event()
+
+    def _is_msg_seen(msg):
+        return False
+
+    # Use router publish to check if `push_msg` succeed.
+    async def router_publish(*args, **kwargs):
+        # The event will only be set if `push_msg` succeed.
+        event.set()
+
+    monkeypatch.setattr(pubsubs_fsub[0], "_is_msg_seen", _is_msg_seen)
+    monkeypatch.setattr(pubsubs_fsub[0].router, "publish", router_publish)
+
+    # Test: no signature attached in `msg`
+    await pubsubs_fsub[0].push_msg(pubsubs_fsub[0].my_id, msg)
+    await asyncio.sleep(0.01)
+    assert not event.is_set()
+
+    # Test: `msg.key` does not match `msg.from_id`
+    msg.key = hosts[1].get_public_key().serialize()
+    msg.signature = signature
+    await pubsubs_fsub[0].push_msg(pubsubs_fsub[0].my_id, msg)
+    await asyncio.sleep(0.01)
+    assert not event.is_set()
+
+    # Test: invalid signature
+    msg.key = hosts[0].get_public_key().serialize()
+    msg.signature = b"\x12" * 100
+    await pubsubs_fsub[0].push_msg(pubsubs_fsub[0].my_id, msg)
+    await asyncio.sleep(0.01)
+    assert not event.is_set()
+
+    # Finally, assert the signature indeed will pass validation
+    msg.key = hosts[0].get_public_key().serialize()
+    msg.signature = signature
+    await pubsubs_fsub[0].push_msg(pubsubs_fsub[0].my_id, msg)
+    await asyncio.sleep(0.01)
+    assert event.is_set()