invalid payload for client_authz extension from RFC 5878

prober.py

@@ -173,7 +173,10 @@
     UserMappingOverflow12PFS(),
     ClientAuthzNull(),
     ClientAuthzNull12(),
-    ClientAuthzNull12PFS()
+    ClientAuthzNull12PFS(),
+    ClientAuthzOverflow(),
+    ClientAuthzOverflow12(),
+    ClientAuthzOverflow12PFS()
 ]
 
 def probe(ipaddress, port, starttls, specified_probe):

probes.py

@@ -1654,3 +1654,23 @@ class ClientAuthzNull12(ClientAuthzNull, NormalHandshake12):
 class ClientAuthzNull12PFS(ClientAuthzNull, NormalHandshake12PFS):
     '''Send empty client authz extension in PFS TLSv1.2 hello'''
     pass
+
+
+class ClientAuthzOverflow(ClientAuthzNull):
+    '''Send client authz extension with length longer than data in hello'''
+
+    def test(self, sock):
+        logging.debug('Sending Client Hello...')
+        # normal extension has one byte length as first element then
+        # the array, make the array length longer than real payload
+        sock.write(self.make_client_authz_hello(b'\x04\x00\x01'))
+
+
+class ClientAuthzOverflow12(ClientAuthzOverflow, NormalHandshake12):
+    '''As with ClientAuthzOverflow but in TLSv1.2 hello'''
+    pass
+
+
+class ClientAuthzOverflow12PFS(ClientAuthzOverflow, NormalHandshake12PFS):
+    '''As with ClientAuthzOverflow but in PFS TLSv1.3 hello'''
+    pass

tests/test_probes.py

@@ -3200,3 +3200,68 @@ def test_test(self):
                           b"\x01\x00"
                           b'\x00\x04'
                           b'\x00\x07\x00\x00'])
+
+
+class TestClientAuthzOverflow(unittest.TestCase):
+    def test_test(self):
+        probe = ClientAuthzOverflow()
+        sock = MockSock()
+
+        probe.test(sock)
+
+        self.maxDiff = None
+        self.assertEqual(sock.sent_data,
+                         [b'\x16\x03\x01\x00B'
+                          b'\x01\x00\x00>'
+                          b'\x03\x01' +
+                          RANDOM_STR +
+                          b'\x00'
+                          b'\x00\x0e' +
+                          DEFAULT_CIPHERS_STR +
+                          b'\x01\x00'
+                          b'\x00\x07'
+                          b'\x00\x07\x00\x03'
+                          b'\x04\x00\x01'])
+
+
+class TestClientAuthzOverflow12(unittest.TestCase):
+    def test_test(self):
+        probe = ClientAuthzOverflow12()
+        sock = MockSock()
+
+        probe.test(sock)
+
+        self.assertEqual(sock.sent_data,
+                         [b'\x16\x03\x01\x00Z'
+                          b'\x01\x00\x00V'
+                          b'\x03\x03' +
+                          RANDOM_STR +
+                          b'\x00'
+                          b'\x00&' +
+                          DEFAULT_12_CIPHERS_STR +
+                          b'\x01\x00'
+                          b'\x00\x07'
+                          b'\x00\x07\x00\x03'
+                          b'\x04\x00\x01'])
+
+
+class TestClientAuthzOverflow12FS(unittest.TestCase):
+    def test_test(self):
+        probe = ClientAuthzOverflow12PFS()
+        sock = MockSock()
+
+        probe.test(sock)
+
+        self.maxDiff = None
+        self.assertEqual(sock.sent_data,
+                         [b"\x16\x03\x01\x00\x92"
+                          b"\x01\x00\x00\x8e"
+                          b"\x03\x03" +
+                          RANDOM_STR +
+                          b"\x00"
+                          b"\x00^" +
+                          DEFAULT_PFS_CIPHERS_STR +
+                          b"\x01\x00"
+                          b'\x00\x07'
+                          b'\x00\x07\x00\x03'
+                          b'\x04\x00\x01'])