Fix pymodbus TLS module conflicts in 3.0.0 (#661)

Developers add/fix features at the same time, then produce the conflicts
in pymodbus' TLS module. This patch tries to fix the conflicts.

pymodbus/client/asynchronous/async_io/__init__.py

@@ -450,9 +450,8 @@ def __init__(self, protocol_class=None, loop=None, framer=None):
         self.framer = framer
         ReconnectingAsyncioModbusTcpClient.__init__(self, protocol_class, loop)
 
-    async def start(self, host, port=802, sslctx=None,
-                    server_hostname=None, certfile=None, keyfile=None,
-                    password=None, **kwargs):
+    async def start(self, host='localhost', port=802, sslctx=None,
+                    certfile=None, keyfile=None, password=None, **kwargs):
         """
         Initiates connection to start client
         :param host: The host to connect to (default localhost)
@@ -463,7 +462,6 @@ async def start(self, host, port=802, sslctx=None,
         :param password: The password for for decrypting client's private key file
         """
         self.sslctx = sslctx_provider(sslctx, certfile, keyfile, password)
-        self.server_hostname = server_hostname
         return await ReconnectingAsyncioModbusTcpClient.start(self, host, port)
 
     async def _connect(self):
@@ -840,8 +838,8 @@ async def init_tcp_client(proto_cls, loop, host, port, **kwargs):
 
 
 async def init_tls_client(proto_cls, loop, host, port, sslctx=None,
-                          server_hostname=None, certfile=None, keyfile=None,
-                          password=None, framer=None, **kwargs):
+                          certfile=None, keyfile=None, password=None,
+                          framer=None, **kwargs):
     """
     Helper function to initialize tcp client
     :param proto_cls:
@@ -858,9 +856,7 @@ async def init_tls_client(proto_cls, loop, host, port, sslctx=None,
     """
     client = ReconnectingAsyncioModbusTlsClient(protocol_class=proto_cls,
                                                 loop=loop, framer=framer)
-    await client.start(host, port, sslctx, server_hostname=server_hostname,
-                       certfile=certfile, keyfile=keyfile, password=password,
-                       **kwargs)
+    await client.start(host, port, sslctx, certfile, keyfile, password)
     return client
 
 

pymodbus/client/asynchronous/factory/tls.py

@@ -48,7 +48,9 @@ def async_io_factory(host="127.0.0.1", port=Defaults.TLSPort, sslctx=None,
                               framer=framer)
         client = loop.run_until_complete(asyncio.gather(cor))[0]
     elif loop is asyncio.get_event_loop():
-        return loop, init_tls_client(proto_cls, loop, host, port)
+        return loop, init_tls_client(proto_cls, loop, host, port,
+                                     sslctx, certfile, keyfile, password,
+                                     framer)
     else:
         cor = init_tls_client(proto_cls, loop, host, port,
                               sslctx, certfile, keyfile, password, framer)

pymodbus/server/sync.py

@@ -376,9 +376,10 @@ class ModbusTlsServer(ModbusTcpServer):
     server context instance.
     """
 
-    def __init__(self, context, framer=None, identity=None,
-                 address=None, handler=None, allow_reuse_address=False,
-                 sslctx=None, certfile=None, keyfile=None, **kwargs):
+    def __init__(self, context, framer=None, identity=None, address=None,
+                 sslctx=None, certfile=None, keyfile=None, password=None,
+                 reqclicert=False, handler=None, allow_reuse_address=False,
+                 **kwargs):
         """ Overloaded initializer for the ModbusTcpServer
 
         If the identify structure is not passed in, the ModbusControlBlock
@@ -388,32 +389,24 @@ def __init__(self, context, framer=None, identity=None,
         :param framer: The framer strategy to use
         :param identity: An optional identify structure
         :param address: An optional (interface, port) to bind to.
-        :param handler: A handler for each client session; default is
-                        ModbusConnectedRequestHandler
-        :param allow_reuse_address: Whether the server will allow the
-                        reuse of an address.
         :param sslctx: The SSLContext to use for TLS (default None and auto
                        create)
         :param certfile: The cert file path for TLS (used if sslctx is None)
         :param keyfile: The key file path for TLS (used if sslctx is None)
+        :param password: The password for for decrypting the private key file
+        :param reqclicert: Force the sever request client's certificate
+        :param handler: A handler for each client session; default is
+                        ModbusConnectedRequestHandler
+        :param allow_reuse_address: Whether the server will allow the
+                        reuse of an address.
         :param ignore_missing_slaves: True to not send errors on a request
                         to a missing slave
         :param broadcast_enable: True to treat unit_id 0 as broadcast address,
                         False to treat 0 as any other unit_id
         """
         framer = framer or ModbusTlsFramer
-        self.sslctx = sslctx
-        if self.sslctx is None:
-            self.sslctx = ssl.create_default_context()
-            self.sslctx.load_cert_chain(certfile=certfile, keyfile=keyfile)
-            # According to MODBUS/TCP Security Protocol Specification, it is
-            # TLSv2 at least
-            self.sslctx.options |= ssl.OP_NO_TLSv1_1
-            self.sslctx.options |= ssl.OP_NO_TLSv1
-            self.sslctx.options |= ssl.OP_NO_SSLv3
-            self.sslctx.options |= ssl.OP_NO_SSLv2
-        self.sslctx.verify_mode = ssl.CERT_OPTIONAL
-        self.sslctx.check_hostname = False
+        self.sslctx = sslctx_provider(sslctx, certfile, keyfile, password,
+                                      reqclicert)
 
         ModbusTcpServer.__init__(self, context, framer, identity, address,
                                  handler, allow_reuse_address, **kwargs)
@@ -627,7 +620,8 @@ def StartTcpServer(context=None, identity=None, address=None,
 
 
 def StartTlsServer(context=None, identity=None, address=None, sslctx=None,
-                   certfile=None, keyfile=None, custom_functions=[], **kwargs):
+                   certfile=None, keyfile=None, password=None, reqclicert=False,
+                   custom_functions=[], **kwargs):
     """ A factory to start and run a tls modbus server
 
     :param context: The ModbusServerContext datastore
@@ -636,14 +630,16 @@ def StartTlsServer(context=None, identity=None, address=None, sslctx=None,
     :param sslctx: The SSLContext to use for TLS (default None and auto create)
     :param certfile: The cert file path for TLS (used if sslctx is None)
     :param keyfile: The key file path for TLS (used if sslctx is None)
+    :param password: The password for for decrypting the private key file
+    :param reqclicert: Force the sever request client's certificate
     :param custom_functions: An optional list of custom function classes
         supported by server instance.
     :param ignore_missing_slaves: True to not send errors on a request to a
                                       missing slave
     """
     framer = kwargs.pop("framer", ModbusTlsFramer)
-    server = ModbusTlsServer(context, framer, identity, address, sslctx=sslctx,
-                             certfile=certfile, keyfile=keyfile, **kwargs)
+    server = ModbusTlsServer(context, framer, identity, address, sslctx,
+                             certfile, keyfile, password, reqclicert, **kwargs)
 
     for f in custom_functions:
         server.decoder.register(f)

test/test_server_sync.py

@@ -16,6 +16,7 @@
 from pymodbus.server.sync import ModbusDisconnectedRequestHandler
 from pymodbus.server.sync import ModbusTcpServer, ModbusTlsServer, ModbusUdpServer, ModbusSerialServer
 from pymodbus.server.sync import StartTcpServer, StartTlsServer, StartUdpServer, StartSerialServer
+from pymodbus.server.tls_helper import sslctx_provider
 from pymodbus.exceptions import NotImplementedException
 from pymodbus.bit_read_message import ReadCoilsRequest, ReadCoilsResponse
 from pymodbus.datastore import ModbusServerContext
@@ -278,23 +279,30 @@ def testTcpServerProcess(self):
     #-----------------------------------------------------------------------#
     # Test TLS Server
     #-----------------------------------------------------------------------#
+    def testTlsSSLCTX_Provider(self):
+        ''' test that sslctx_provider() produce SSLContext correctly '''
+        with patch.object(ssl.SSLContext, 'load_cert_chain'):
+            sslctx = sslctx_provider(reqclicert=True)
+            self.assertIsNotNone(sslctx)
+            self.assertEqual(type(sslctx), ssl.SSLContext)
+            self.assertEqual(sslctx.verify_mode, ssl.CERT_REQUIRED)
+
+            sslctx_old = ssl.SSLContext(ssl.PROTOCOL_TLSv1_2)
+            sslctx_new = sslctx_provider(sslctx=sslctx_old)
+            self.assertEqual(sslctx_new, sslctx_old)
+
     def testTlsServerInit(self):
         ''' test that the synchronous TLS server initial correctly '''
         with patch.object(socketserver.TCPServer, 'server_activate'):
             with patch.object(ssl.SSLContext, 'load_cert_chain') as mock_method:
                 identity = ModbusDeviceIdentification(info={0x00: 'VendorName'})
                 server = ModbusTlsServer(context=None, identity=identity,
+                                         reqclicert=True,
                                          bind_and_activate=False)
                 self.assertIs(server.framer, ModbusTlsFramer)
                 server.server_activate()
                 self.assertIsNotNone(server.sslctx)
-                self.assertEqual(type(server.socket), ssl.SSLSocket)
-                server.server_close()
-                sslctx = ssl.create_default_context()
-                server = ModbusTlsServer(context=None, identity=identity,
-                                         sslctx=sslctx, bind_and_activate=False)
-                server.server_activate()
-                self.assertEqual(server.sslctx, sslctx)
+                self.assertEqual(server.sslctx.verify_mode, ssl.CERT_REQUIRED)
                 self.assertEqual(type(server.socket), ssl.SSLSocket)
                 server.server_close()