Gracefully fail to decode empty packets (Fixes #269)

miguelgrinberg · May 29, 2022 · 9c65707 · 9c65707
1 parent 3345a59
commit 9c65707
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Showing 2 changed files with 6 additions and 0 deletions.
diff --git a/src/engineio/packet.py b/src/engineio/packet.py
@@ -48,6 +48,8 @@ def encode(self, b64=False):
     def decode(self, encoded_packet):
         """Decode a transmitted package."""
         self.binary = isinstance(encoded_packet, binary_types)
+        if not self.binary and len(encoded_packet) == 0:
+            raise ValueError('Invalid empty packet received')
         b64 = not self.binary and encoded_packet[0] == 'b'
         if b64:
             self.binary = True

diff --git a/tests/common/test_packet.py b/tests/common/test_packet.py
@@ -130,3 +130,7 @@ def test_decode_number_packet(self):
     def test_binary_non_message_packet(self):
         with pytest.raises(ValueError):
             packet.Packet(packet.NOOP, b'\x01\x02\x03')
+
+    def test_decode_invalid_empty_text_packet(self):
+        with pytest.raises(ValueError):
+            packet.Packet(encoded_packet='')