fix(dingtalk): harden group reply sender labels

nanobot/channels/dingtalk/runtime.py

@@ -24,6 +24,17 @@ from nanobot.security.network import validate_resolved_url, validate_url_target
 
 DINGTALK_MAX_REMOTE_MEDIA_BYTES = 20 * 1024 * 1024
 DINGTALK_MAX_REMOTE_MEDIA_REDIRECTS = 3
+_DINGTALK_MARKDOWN_INLINE_SPECIALS = frozenset(r"\`*_{}[]()<>#+-.!|~")
+_DINGTALK_SENDER_NAME_MAX_CHARS = 80
+
+
+def _escape_markdown_sender_name(value: str) -> str:
+    """Render an untrusted display name as one bounded Markdown-safe line."""
+    normalized = " ".join(value.split())[:_DINGTALK_SENDER_NAME_MAX_CHARS]
+    return "".join(
+        f"\\{char}" if char in _DINGTALK_MARKDOWN_INLINE_SPECIALS else char
+        for char in normalized
+    )
 
 try:
     from dingtalk_stream import (
@@ -719,8 +730,13 @@ class DingTalkChannel(BaseChannel):
             # sender so the addressed user can spot the reply. Visual only —
             # DingTalk's markdown robot messages do not push real @ notifications.
             sender_name = msg.metadata.get("sender_name") if msg.metadata else None
-            if msg.chat_id.startswith("group:") and sender_name:
-                content = f"# @{sender_name}\n\n{content}"
+            safe_sender_name = (
+                _escape_markdown_sender_name(sender_name)
+                if isinstance(sender_name, str)
+                else ""
+            )
+            if msg.chat_id.startswith("group:") and safe_sender_name:
+                content = f"# @{safe_sender_name}\n\n{content}"
             if not await self._send_markdown_text(token, msg.chat_id, content):
                 raise RuntimeError("DingTalk text message was not delivered")
 
@@ -741,7 +757,7 @@ class DingTalkChannel(BaseChannel):
     async def _on_message(
         self,
         content: str,
-        sender_id: str,
+        sender_id: str | None,
         sender_name: str,
         conversation_type: str | None = None,
         conversation_id: str | None = None,
@@ -753,6 +769,9 @@ class DingTalkChannel(BaseChannel):
         """
         try:
             self.logger.info("inbound: {} from {}", content, sender_name)
+            if not sender_id:
+                self.logger.warning("dropping DingTalk message without a sender ID")
+                return
             is_group = conversation_type == "2" and conversation_id
             chat_id = f"group:{conversation_id}" if is_group else sender_id
             session_key = None
@@ -768,7 +787,7 @@ class DingTalkChannel(BaseChannel):
                 await self.send(
                     OutboundMessage(
                         channel=self.name,
-                        chat_id=str(chat_id),  # str() guards a None sender_id
+                        chat_id=chat_id,
                         content="该机器人未开启私聊，请在群聊中与我对话。",
                     )
                 )

nanobot/channels/dingtalk/tests/test_dingtalk_channel.py

@@ -10,15 +10,15 @@ import pytest
 
 # Check optional dingtalk dependencies before running tests
 try:
-    from nanobot.channels import dingtalk
-    DINGTALK_AVAILABLE = getattr(dingtalk, "DINGTALK_AVAILABLE", False)
+    import nanobot.channels.dingtalk.runtime as dingtalk_module
+
+    DINGTALK_AVAILABLE = dingtalk_module.DINGTALK_AVAILABLE
 except ImportError:
     DINGTALK_AVAILABLE = False
 
 if not DINGTALK_AVAILABLE:
     pytest.skip("DingTalk dependencies not installed (dingtalk-stream)", allow_module_level=True)
 
-import nanobot.channels.dingtalk.runtime as dingtalk_module
 from nanobot.bus.events import OutboundMessage
 from nanobot.bus.queue import MessageBus
 from nanobot.channels.dingtalk.runtime import (
@@ -154,6 +154,13 @@ async def test_group_user_isolation_true_separates_sessions() -> None:
     assert msg1.chat_id == msg2.chat_id == "group:conv123"
 
 
+def test_disable_private_chat_uses_camel_case_config_key() -> None:
+    config = DingTalkConfig.model_validate({"disablePrivateChat": True})
+
+    assert config.disable_private_chat is True
+    assert config.model_dump(mode="json", by_alias=True)["disablePrivateChat"] is True
+
+
 @pytest.mark.asyncio
 async def test_dm_rejected_when_private_chat_disabled(monkeypatch) -> None:
     """With disable_private_chat=True, a 1:1 DM is rejected: nothing reaches the
@@ -278,6 +285,31 @@ async def test_group_send_prepends_sender_mention(monkeypatch) -> None:
     assert sent_text == "# @Alice\n\nhello"
 
 
+@pytest.mark.asyncio
+async def test_group_send_escapes_untrusted_sender_name(monkeypatch) -> None:
+    """A sender nickname cannot inject extra Markdown blocks into the reply."""
+    config = DingTalkConfig(client_id="app", client_secret="secret", allow_from=["*"])
+    channel = DingTalkChannel(config, MessageBus())
+    channel._http = _FakeHttp()
+
+    async def _fake_token() -> str:
+        return "token"
+
+    monkeypatch.setattr(channel, "_get_access_token", _fake_token)
+
+    await channel.send(
+        OutboundMessage(
+            channel="dingtalk",
+            chat_id="group:conv123",
+            content="hello",
+            metadata={"sender_name": "Alice\n# [click](https://evil) *admin*"},
+        )
+    )
+
+    sent_text = json.loads(channel._http.calls[0]["json"]["msgParam"])["text"]
+    assert sent_text == r"# @Alice \# \[click\]\(https://evil\) \*admin\*" + "\n\nhello"
+
+
 @pytest.mark.asyncio
 async def test_private_send_does_not_prepend_mention(monkeypatch) -> None:
     """Private replies are sent verbatim, without the sender header."""
@@ -303,6 +335,30 @@ async def test_private_send_does_not_prepend_mention(monkeypatch) -> None:
     assert sent_text == "hello"
 
 
+@pytest.mark.asyncio
+async def test_message_without_sender_id_is_dropped() -> None:
+    """Malformed inbound events must not publish or attempt an invalid reply."""
+    config = DingTalkConfig(
+        client_id="app",
+        client_secret="secret",
+        allow_from=["*"],
+        disable_private_chat=True,
+    )
+    bus = MessageBus()
+    channel = DingTalkChannel(config, bus)
+    channel._http = _FakeHttp()
+
+    await channel._on_message(
+        "hello",
+        sender_id=None,
+        sender_name="Unknown",
+        conversation_type="1",
+    )
+
+    assert bus.inbound.empty()
+    assert channel._http.calls == []
+
+
 @pytest.mark.asyncio
 async def test_handler_uses_voice_recognition_text_when_text_is_empty(monkeypatch) -> None:
     bus = MessageBus()