From d9fb70e8edf52caa63e2665cbda637dc73f5add4 Mon Sep 17 00:00:00 2001
From: kdmukai <kdmukai@gmail.com>
Date: Thu, 19 Jan 2023 17:28:57 -0600
Subject: [PATCH] Integrate Event and RelayManager w/validity checking (#30)

---
 README.md                  |  3 +--
 nostr/event.py             | 27 +++++++++++++++++----------
 nostr/relay_manager.py     | 22 +++++++++++++++++++++-
 test/test_relay_manager.py | 30 ++++++++++++++++++++++++++++++
 4 files changed, 69 insertions(+), 13 deletions(-)
 create mode 100644 test/test_relay_manager.py

diff --git a/README.md b/README.md
index f00def5..42f7486 100644
--- a/README.md
+++ b/README.md
@@ -51,8 +51,7 @@ private_key = PrivateKey()
 event = Event(private_key.public_key.hex(), "Hello Nostr")
 event.sign(private_key.hex())
 
-message = json.dumps([ClientMessageType.EVENT, event.to_json_object()])
-relay_manager.publish_message(message)
+relay_manager.publish_event(event)
 time.sleep(1) # allow the messages to send
 
 relay_manager.close_connections()
diff --git a/nostr/event.py b/nostr/event.py
index b5ee4f6..10d3829 100644
--- a/nostr/event.py
+++ b/nostr/event.py
@@ -4,6 +4,8 @@ from enum import IntEnum
 from secp256k1 import PrivateKey, PublicKey
 from hashlib import sha256
 
+from nostr.message_type import ClientMessageType
+
 
 class EventKind(IntEnum):
     SET_METADATA = 0
@@ -55,13 +57,18 @@ class Event():
         event_id = Event.compute_id(self.public_key, self.created_at, self.kind, self.tags, self.content)
         return pub_key.schnorr_verify(bytes.fromhex(event_id), bytes.fromhex(self.signature), None, raw=True)
 
-    def to_json_object(self) -> dict:
-        return {
-            "id": self.id,
-            "pubkey": self.public_key,
-            "created_at": self.created_at,
-            "kind": self.kind,
-            "tags": self.tags,
-            "content": self.content,
-            "sig": self.signature
-        }
+    def to_message(self) -> str:
+        return json.dumps(
+            [
+                ClientMessageType.EVENT,
+                {
+                    "id": self.id,
+                    "pubkey": self.public_key,
+                    "created_at": self.created_at,
+                    "kind": self.kind,
+                    "tags": self.tags,
+                    "content": self.content,
+                    "sig": self.signature
+                }
+            ]
+        )
diff --git a/nostr/relay_manager.py b/nostr/relay_manager.py
index e4d177e..c0664f6 100644
--- a/nostr/relay_manager.py
+++ b/nostr/relay_manager.py
@@ -1,8 +1,19 @@
+import json
 import threading
+
+from .event import Event
 from .filter import Filters
 from .message_pool import MessagePool
+from .message_type import ClientMessageType
 from .relay import Relay, RelayPolicy
 
+
+
+class RelayException(Exception):
+    pass
+
+
+
 class RelayManager:
     def __init__(self) -> None:
         self.relays: dict[str, Relay] = {}
@@ -40,4 +51,13 @@ class RelayManager:
         for relay in self.relays.values():
             if relay.policy.should_write:
                 relay.publish(message)
-            
+
+    def publish_event(self, event: Event):
+        """ Verifies that the Event is publishable before submitting it to relays """
+        if event.signature is None:
+            raise RelayException(f"Could not publish {event.id}: must be signed")
+
+        if not event.verify():
+            raise RelayException(f"Could not publish {event.id}: failed to verify signature {event.signature}")
+
+        self.publish_message(event.to_message())
diff --git a/test/test_relay_manager.py b/test/test_relay_manager.py
new file mode 100644
index 0000000..c6e838a
--- /dev/null
+++ b/test/test_relay_manager.py
@@ -0,0 +1,30 @@
+import pytest
+from nostr.event import Event
+from nostr.key import PrivateKey
+from nostr.relay_manager import RelayManager, RelayException
+
+
+def test_only_relay_valid_events():
+    """ publish_event raise a RelayException if an Event fails verification """
+    pk = PrivateKey()
+    event = Event(
+        public_key=pk.public_key.hex(),
+        content="Hello, world!",
+    )
+    
+    relay_manager = RelayManager()
+
+    # Deliberately forget to sign the Event
+    with pytest.raises(RelayException) as e:
+        relay_manager.publish_event(event)
+    assert "must be signed" in str(e)
+
+    # Attempt to relay with a nonsense signature
+    event.signature = '0' * 32
+    with pytest.raises(RelayException) as e:
+        relay_manager.publish_event(event)
+    assert "failed to verify" in str(e)
+
+    # Properly signed Event can be relayed
+    event.sign(pk.hex())
+    relay_manager.publish_event(event)