fix(security): widen non-ASCII compare_digest crash fix to all sibling sites

Same bug class as the salvaged #65305/#65307: hmac.compare_digest (and
secrets.compare_digest) raise TypeError when given a str containing
non-ASCII characters, and these call sites feed it raw request input.
Compare as UTF-8 bytes everywhere:

- gateway/platforms/msgraph_webhook.py: clientState from request body
- gateway/platforms/whatsapp_cloud.py: hub.verify_token query param +
  X-Hub-Signature-256 header (comment claimed 'works on str' — it
  doesn't for non-ASCII)
- plugins/platforms/feishu: verification token + x-lark-signature
- plugins/platforms/raft: bridge token header
- plugins/platforms/line: X-Line-Signature
- plugins/platforms/sms: X-Twilio-Signature
- tools/code_execution_tool.py: sandbox RPC token (both loops)

Regression tests for the two gateway-core sites (msgraph, whatsapp).

gateway/platforms/msgraph_webhook.py

@@ -358,7 +358,9 @@ class MSGraphWebhookAdapter(BasePlatformAdapter):
         provided = self._string_or_none(notification.get("clientState"))
         if provided is None:
             return False
-        return hmac.compare_digest(provided, expected)
+        # Compare as bytes: ``compare_digest`` raises TypeError on a str with
+        # non-ASCII characters, and clientState comes from the request body.
+        return hmac.compare_digest(provided.encode(), expected.encode())
 
     def _has_seen_receipt(self, receipt_key: str) -> bool:
         return receipt_key in self._seen_receipts

gateway/platforms/whatsapp_cloud.py

@@ -1413,10 +1413,11 @@ class WhatsAppCloudAdapter(WhatsAppBehaviorMixin, BasePlatformAdapter):
             return web.Response(status=400, text="bad mode")
 
         # Constant-time compare to avoid token-length / token-content leaks
-        # via timing. ``hmac.compare_digest`` works on str.
+        # via timing. Compare as bytes: ``compare_digest`` raises TypeError on
+        # a str with non-ASCII characters, and the token is a raw query param.
         import hmac as _hmac
 
-        if not _hmac.compare_digest(token, self._verify_token):
+        if not _hmac.compare_digest(token.encode(), self._verify_token.encode()):
             return web.Response(status=403, text="verify_token mismatch")
         if not challenge:
             return web.Response(status=400, text="missing challenge")
@@ -1509,7 +1510,11 @@ class WhatsAppCloudAdapter(WhatsAppBehaviorMixin, BasePlatformAdapter):
             raw_body,
             hashlib.sha256,
         ).hexdigest()
-        return hmac.compare_digest(computed.lower(), expected_hex.lower())
+        # Compare as bytes: compare_digest raises TypeError on a str with
+        # non-ASCII characters, and the signature is a raw request header.
+        return hmac.compare_digest(
+            computed.lower().encode(), expected_hex.lower().encode()
+        )
 
     # ------------------------------------------------------------------ dispatch
     def _dedup_wamid(self, wamid: str) -> bool:

plugins/platforms/feishu/adapter.py

@@ -3512,7 +3512,11 @@ class FeishuAdapter(BasePlatformAdapter):
         if self._verification_token:
             header = payload.get("header") or {}
             incoming_token = str(header.get("token") or payload.get("token") or "")
-            if not incoming_token or not hmac.compare_digest(incoming_token, self._verification_token):
+            # Compare as bytes: compare_digest raises TypeError on a str with
+            # non-ASCII characters, and the token comes from the request body.
+            if not incoming_token or not hmac.compare_digest(
+                incoming_token.encode(), self._verification_token.encode()
+            ):
                 logger.warning("[Feishu] Webhook rejected: invalid verification token from %s", remote_ip)
                 self._record_webhook_anomaly(remote_ip, "401-token")
                 return web.Response(status=401, text="Invalid verification token")
@@ -3575,7 +3579,9 @@ class FeishuAdapter(BasePlatformAdapter):
             body_str = body_bytes.decode("utf-8", errors="replace")
             content = f"{timestamp}{nonce}{self._encrypt_key}{body_str}"
             computed = hashlib.sha256(content.encode("utf-8")).hexdigest()
-            return hmac.compare_digest(computed, signature)
+            # Compare as bytes: compare_digest raises TypeError on a str with
+            # non-ASCII characters, and the signature is a raw request header.
+            return hmac.compare_digest(computed.encode(), signature.encode())
         except Exception:
             logger.debug("[Feishu] Signature verification raised an exception", exc_info=True)
             return False

plugins/platforms/line/adapter.py

@@ -273,7 +273,9 @@ def verify_line_signature(body: bytes, signature: str, channel_secret: str) -> b
         expected = base64.b64encode(digest).decode("utf-8")
     except Exception:
         return False
-    return hmac.compare_digest(expected, signature)
+    # Compare as bytes: compare_digest raises TypeError on a str with
+    # non-ASCII characters, and the signature is a raw request header.
+    return hmac.compare_digest(expected.encode(), signature.encode())
 
 
 # ---------------------------------------------------------------------------

plugins/platforms/raft/adapter.py

@@ -692,7 +692,9 @@ class RaftAdapter(BasePlatformAdapter):
     def _validate_bridge_token(self, token: str) -> bool:
         if not self._bridge_token or not token:
             return False
-        return hmac.compare_digest(token, self._bridge_token)
+        # Compare as bytes: compare_digest raises TypeError on a str with
+        # non-ASCII characters, and the token is a raw request header.
+        return hmac.compare_digest(token.encode(), self._bridge_token.encode())
 
     async def _accept_wake(self, payload: Dict[str, Any]) -> bool:
         if not self._message_handler:

plugins/platforms/sms/adapter.py

@@ -257,7 +257,9 @@ class SmsAdapter(BasePlatformAdapter):
             hashlib.sha1,
         )
         computed = base64.b64encode(mac.digest()).decode("utf-8")
-        return hmac.compare_digest(computed, signature)
+        # Compare as bytes: compare_digest raises TypeError on a str with
+        # non-ASCII characters, and the signature is a raw request header.
+        return hmac.compare_digest(computed.encode(), signature.encode())
 
     @staticmethod
     def _port_variant_url(url: str) -> str | None:

tests/gateway/test_msgraph_webhook.py

@@ -316,8 +316,30 @@ class TestMSGraphNotifications:
 
         assert calls, "hmac.compare_digest was never called; clientState check is not timing-safe"
         provided, expected = calls[0]
-        assert provided == "expected-client-state"
-        assert expected == "expected-client-state"
+        assert provided == b"expected-client-state"
+        assert expected == b"expected-client-state"
+
+    @pytest.mark.anyio
+    async def test_non_ascii_client_state_rejected_without_raising(self):
+        """A non-ASCII clientState (attacker-controlled request body) must be
+        rejected with 403, not crash the handler: hmac.compare_digest raises
+        TypeError on a str containing non-ASCII characters."""
+        adapter = _make_adapter()
+        payload = {
+            "value": [
+                {
+                    "id": "notif-nonascii",
+                    "subscriptionId": "sub-1",
+                    "changeType": "updated",
+                    "resource": "communications/onlineMeetings/meeting-x",
+                    "clientState": "ské-not-the-secret",
+                }
+            ]
+        }
+        response = await adapter._handle_notification(
+            _FakeRequest(json_payload=payload)
+        )
+        assert response.status == 403
 
     @pytest.mark.anyio
     async def test_duplicate_notification_deduped(self):

tests/gateway/test_whatsapp_cloud.py

@@ -353,6 +353,22 @@ class TestWebhookVerify:
 
         assert response.status == 403
 
+    @pytest.mark.asyncio
+    async def test_verify_rejects_non_ascii_token_without_raising(self):
+        """A non-ASCII verify_token (raw query param) must be rejected with
+        403, not crash the handler: hmac.compare_digest raises TypeError on a
+        str containing non-ASCII characters."""
+        adapter = _make_adapter(verify_token="shared-secret-123")
+        request = _verify_request({
+            "hub.mode": "subscribe",
+            "hub.verify_token": "ské-not-the-secret",
+            "hub.challenge": "abc-12345",
+        })
+
+        response = await adapter._handle_verify(request)
+
+        assert response.status == 403
+
     @pytest.mark.asyncio
     async def test_verify_rejects_wrong_mode(self):
         adapter = _make_adapter(verify_token="shared-secret-123")

tools/code_execution_tool.py

@@ -596,7 +596,10 @@ def _rpc_server_loop(
                     continue
 
                 if not rpc_token or not secrets.compare_digest(
-                    str(request.get("token") or ""), rpc_token
+                    # Compare as bytes: compare_digest raises TypeError on a
+                    # str with non-ASCII characters, and the token comes from
+                    # sandbox-script-supplied JSON.
+                    str(request.get("token") or "").encode(), rpc_token.encode()
                 ):
                     resp = json.dumps({"error": "Unauthorized RPC request"})
                     conn.sendall((resp + "\n").encode())
@@ -881,7 +884,10 @@ def _rpc_poll_loop(
                     continue
 
                 if not rpc_token or not secrets.compare_digest(
-                    str(request.get("token") or ""), rpc_token
+                    # Compare as bytes: compare_digest raises TypeError on a
+                    # str with non-ASCII characters, and the token comes from
+                    # sandbox-script-supplied JSON.
+                    str(request.get("token") or "").encode(), rpc_token.encode()
                 ):
                     logger.debug("Unauthorized RPC request in %s", req_file)
                     env.execute(f"rm -f {quoted_req_file}", cwd="/", timeout=5)