cap request body to prevent memory DoS

Both search handlers trusted the client-supplied Content-Length and
passed it straight to `rfile.read()`, so a single request with a
forged `Content-Length: 1073741824` would allocate gigabytes. Clamp
to 64 KiB, well above any legitimate search payload.

eirescope/web/app.py

@@ -40,6 +40,9 @@ _db_path = os.path.join(tempfile.gettempdir(), "eirescope_investigations.db")
 db = Database(_db_path)
 engine = InvestigationEngine()
 
+# Cap request body to prevent memory DoS from forged Content-Length.
+MAX_REQUEST_BODY = 64 * 1024  # 64 KiB
+
 
 class EireScopeHandler(BaseHTTPRequestHandler):
     """HTTP Request handler for EireScope web interface."""
@@ -103,7 +106,7 @@ class EireScopeHandler(BaseHTTPRequestHandler):
 
     def _handle_search_form(self):
         """Handle form-based search submission."""
-        content_length = int(self.headers.get("Content-Length", 0))
+        content_length = min(int(self.headers.get("Content-Length", 0)), MAX_REQUEST_BODY)
         body = self.rfile.read(content_length).decode("utf-8")
         params = urllib.parse.parse_qs(body)
 
@@ -134,7 +137,7 @@ class EireScopeHandler(BaseHTTPRequestHandler):
 
     def _handle_search(self):
         """Handle API search (JSON)."""
-        content_length = int(self.headers.get("Content-Length", 0))
+        content_length = min(int(self.headers.get("Content-Length", 0)), MAX_REQUEST_BODY)
         body = json.loads(self.rfile.read(content_length).decode("utf-8"))
 
         query = body.get("query", "").strip()