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from __future__ import division # support for python2 |
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2
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1 |
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from threading import Thread, Condition |
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3
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1 |
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import logging |
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4
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1 |
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try: |
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5
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from urllib.parse import urlparse |
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except ImportError: # support for python2 |
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7
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from urlparse import urlparse |
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8
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9
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1 |
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from opcua import ua |
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10
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1 |
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from opcua.client.ua_client import UaClient |
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1 |
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from opcua.common.node import Node |
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12
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1 |
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from opcua.common.manage_nodes import delete_nodes |
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1 |
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from opcua.common.subscription import Subscription |
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1 |
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from opcua.common import utils |
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15
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1 |
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from opcua.crypto import security_policies |
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1 |
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use_crypto = True |
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17
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1 |
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try: |
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18
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from opcua.crypto import uacrypto |
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19
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1 |
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except ImportError: |
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20
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print("cryptography is not installed, use of crypto disabled") |
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use_crypto = False |
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22
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23
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24
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1 |
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class KeepAlive(Thread): |
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""" |
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Used by Client to keep session opened. |
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28
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OPCUA defines timeout both for sessions and secure channel |
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29
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""" |
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30
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31
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1 |
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def __init__(self, client, timeout): |
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32
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Thread.__init__(self) |
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33
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1 |
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self.logger = logging.getLogger(__name__) |
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34
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1 |
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if timeout == 0: # means no timeout bu we do not trust such servers |
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35
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timeout = 360000 |
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36
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1 |
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self.timeout = timeout |
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37
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1 |
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self.client = client |
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38
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1 |
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self._dostop = False |
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39
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1 |
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self._cond = Condition() |
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40
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41
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1 |
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def run(self): |
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42
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1 |
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self.logger.debug("starting keepalive thread with period of %s milliseconds", self.timeout) |
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43
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1 |
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server_state = self.client.get_node(ua.FourByteNodeId(ua.ObjectIds.Server_ServerStatus_State)) |
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44
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1 |
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while not self._dostop: |
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45
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1 |
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with self._cond: |
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46
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1 |
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self._cond.wait(self.timeout / 1000) |
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47
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1 |
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if self._dostop: |
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48
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1 |
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break |
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49
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self.logger.debug("renewing channel") |
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50
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self.client.open_secure_channel(renew=True) |
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51
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val = server_state.get_value() |
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52
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self.logger.debug("server state is: %s ", val) |
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53
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1 |
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self.logger.debug("keepalive thread has stopped") |
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54
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55
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1 |
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def stop(self): |
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56
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1 |
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self.logger.debug("stoping keepalive thread") |
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57
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1 |
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self._dostop = True |
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58
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1 |
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with self._cond: |
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59
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1 |
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self._cond.notify_all() |
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60
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61
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62
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1 |
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class Client(object): |
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63
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64
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""" |
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65
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High level client to connect to an OPC-UA server. |
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66
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67
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This class makes it easy to connect and browse address space. |
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68
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It attemps to expose as much functionality as possible |
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69
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but if you want more flexibility it is possible and adviced to |
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70
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use UaClient object, available as self.uaclient |
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71
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which offers the raw OPC-UA services interface. |
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72
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""" |
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73
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74
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1 |
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def __init__(self, url, timeout=4): |
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75
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""" |
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76
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used url argument to connect to server. |
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77
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if you are unsure of url, write at least hostname and port |
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78
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and call get_endpoints |
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79
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timeout is the timeout to get an answer for requests to server |
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80
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public member of this call are available to be set by API users |
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81
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82
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""" |
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83
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1 |
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self.logger = logging.getLogger(__name__) |
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84
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1 |
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self.server_url = urlparse(url) |
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85
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1 |
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self.name = "Pure Python Client" |
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86
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1 |
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self.description = self.name |
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87
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1 |
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self.application_uri = "urn:freeopcua:client" |
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88
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1 |
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self.product_uri = "urn:freeopcua.github.no:client" |
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89
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1 |
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self.security_policy = ua.SecurityPolicy() |
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90
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1 |
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self.secure_channel_id = None |
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91
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1 |
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self.default_timeout = 3600000 |
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92
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1 |
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self.secure_channel_timeout = self.default_timeout |
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93
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1 |
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self.session_timeout = self.default_timeout |
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94
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1 |
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self._policy_ids = [] |
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95
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1 |
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self.uaclient = UaClient(timeout) |
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96
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1 |
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self.user_certificate = None |
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97
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1 |
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self.user_private_key = None |
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98
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1 |
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self._session_counter = 1 |
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99
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1 |
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self.keepalive = None |
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100
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101
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1 |
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@staticmethod |
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102
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def find_endpoint(endpoints, security_mode, policy_uri): |
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103
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""" |
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104
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Find endpoint with required security mode and policy URI |
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105
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""" |
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106
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1 |
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for ep in endpoints: |
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107
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1 |
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if (ep.EndpointUrl.startswith(ua.OPC_TCP_SCHEME) and |
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108
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ep.SecurityMode == security_mode and |
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109
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ep.SecurityPolicyUri == policy_uri): |
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110
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1 |
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return ep |
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111
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raise ValueError("No matching endpoints: {}, {}".format( |
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112
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security_mode, policy_uri)) |
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113
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114
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1 |
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def set_security_string(self, string): |
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115
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""" |
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116
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Set SecureConnection mode. String format: |
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117
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Policy,Mode,certificate,private_key[,server_private_key] |
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118
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where Policy is Basic128Rsa15 or Basic256, |
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119
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Mode is Sign or SignAndEncrypt |
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120
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certificate, private_key and server_private_key are |
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121
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paths to .pem or .der files |
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122
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Call this before connect() |
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123
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""" |
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124
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if not string: |
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125
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return |
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126
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parts = string.split(',') |
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127
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if len(parts) < 4: |
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128
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raise UaError('Wrong format: `{}`, expected at least 4 ' |
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129
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'comma-separated values'.format(string)) |
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130
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policy_class = getattr(security_policies, 'SecurityPolicy' + parts[0]) |
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131
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mode = getattr(ua.MessageSecurityMode, parts[1]) |
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132
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return self.set_security(policy_class, parts[2], parts[3], |
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133
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parts[4] if len(parts) >= 5 else None, mode) |
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134
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135
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1 |
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def set_security(self, policy, certificate_path, private_key_path, |
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136
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server_certificate_path=None, |
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137
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mode=ua.MessageSecurityMode.SignAndEncrypt): |
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138
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""" |
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139
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Set SecureConnection mode. |
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140
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Call this before connect() |
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141
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""" |
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142
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if server_certificate_path is None: |
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143
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# load certificate from server's list of endpoints |
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144
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endpoints = self.connect_and_get_server_endpoints() |
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145
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endpoint = Client.find_endpoint(endpoints, mode, policy.URI) |
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146
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server_cert = uacrypto.x509_from_der(endpoint.ServerCertificate) |
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147
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else: |
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148
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server_cert = uacrypto.load_certificate(server_certificate_path) |
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149
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cert = uacrypto.load_certificate(certificate_path) |
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150
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pk = uacrypto.load_private_key(private_key_path) |
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151
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self.security_policy = policy(server_cert, cert, pk, mode) |
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152
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self.uaclient.set_security(self.security_policy) |
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153
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154
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1 |
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def load_client_certificate(self, path): |
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155
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""" |
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156
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load our certificate from file, either pem or der |
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157
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""" |
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158
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self.user_certificate = uacrypto.load_certificate(path) |
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159
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160
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1 |
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def load_private_key(self, path): |
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161
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self.user_private_key = uacrypto.load_private_key(path) |
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162
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163
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1 |
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def connect_and_get_server_endpoints(self): |
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164
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""" |
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165
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Connect, ask server for endpoints, and disconnect |
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166
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""" |
|
167
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self.connect_socket() |
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168
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self.send_hello() |
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169
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self.open_secure_channel() |
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170
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endpoints = self.get_endpoints() |
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171
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self.close_secure_channel() |
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172
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self.disconnect_socket() |
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173
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return endpoints |
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174
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|
175
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1 |
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def connect_and_find_servers(self): |
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176
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""" |
|
177
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Connect, ask server for a list of known servers, and disconnect |
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178
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""" |
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179
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self.connect_socket() |
|
180
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self.send_hello() |
|
181
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self.open_secure_channel() # spec says it should not be necessary to open channel |
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182
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servers = self.find_servers() |
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183
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self.close_secure_channel() |
|
184
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self.disconnect_socket() |
|
185
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return servers |
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186
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187
|
1 |
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def connect_and_find_servers_on_network(self): |
|
188
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""" |
|
189
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Connect, ask server for a list of known servers on network, and disconnect |
|
190
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""" |
|
191
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self.connect_socket() |
|
192
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self.send_hello() |
|
193
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self.open_secure_channel() |
|
194
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servers = self.find_servers_on_network() |
|
195
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self.close_secure_channel() |
|
196
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self.disconnect_socket() |
|
197
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return servers |
|
198
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|
199
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1 |
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def connect(self): |
|
200
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""" |
|
201
|
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|
High level method |
|
202
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Connect, create and activate session |
|
203
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""" |
|
204
|
1 |
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self.connect_socket() |
|
205
|
1 |
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self.send_hello() |
|
206
|
1 |
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self.open_secure_channel() |
|
207
|
1 |
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self.create_session() |
|
208
|
1 |
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self.activate_session(username=self.server_url.username, password=self.server_url.password, certificate=self.user_certificate) |
|
209
|
|
|
|
|
210
|
1 |
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def disconnect(self): |
|
211
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""" |
|
212
|
|
|
High level method |
|
213
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|
|
Close session, secure channel and socket |
|
214
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|
""" |
|
215
|
1 |
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self.close_session() |
|
216
|
1 |
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self.close_secure_channel() |
|
217
|
1 |
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self.disconnect_socket() |
|
218
|
|
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|
|
219
|
1 |
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def connect_socket(self): |
|
220
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""" |
|
221
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connect to socket defined in url |
|
222
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|
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""" |
|
223
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1 |
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self.uaclient.connect_socket(self.server_url.hostname, self.server_url.port) |
|
224
|
|
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|
|
225
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1 |
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def disconnect_socket(self): |
|
226
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1 |
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self.uaclient.disconnect_socket() |
|
227
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228
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1 |
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def send_hello(self): |
|
229
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|
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""" |
|
230
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Send OPC-UA hello to server |
|
231
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|
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""" |
|
232
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1 |
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ack = self.uaclient.send_hello(self.server_url.geturl()) |
|
233
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# FIXME check ack |
|
234
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|
235
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1 |
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def open_secure_channel(self, renew=False): |
|
236
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""" |
|
237
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Open secure channel, if renew is True, renew channel |
|
238
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|
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""" |
|
239
|
1 |
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params = ua.OpenSecureChannelParameters() |
|
240
|
1 |
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params.ClientProtocolVersion = 0 |
|
241
|
1 |
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params.RequestType = ua.SecurityTokenRequestType.Issue |
|
242
|
1 |
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if renew: |
|
243
|
|
|
params.RequestType = ua.SecurityTokenRequestType.Renew |
|
244
|
1 |
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params.SecurityMode = self.security_policy.Mode |
|
245
|
1 |
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params.RequestedLifetime = self.secure_channel_timeout |
|
246
|
1 |
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nonce = utils.create_nonce(self.security_policy.symmetric_key_size) # length should be equal to the length of key of symmetric encryption |
|
247
|
1 |
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params.ClientNonce = nonce # this nonce is used to create a symmetric key |
|
248
|
1 |
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result = self.uaclient.open_secure_channel(params) |
|
249
|
1 |
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self.security_policy.make_symmetric_key(nonce, result.ServerNonce) |
|
250
|
1 |
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self.secure_channel_timeout = result.SecurityToken.RevisedLifetime |
|
251
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|
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|
252
|
1 |
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def close_secure_channel(self): |
|
253
|
1 |
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return self.uaclient.close_secure_channel() |
|
254
|
|
|
|
|
255
|
1 |
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def get_endpoints(self): |
|
256
|
1 |
|
params = ua.GetEndpointsParameters() |
|
257
|
1 |
|
params.EndpointUrl = self.server_url.geturl() |
|
258
|
1 |
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return self.uaclient.get_endpoints(params) |
|
259
|
|
|
|
|
260
|
1 |
|
def register_server(self, server, discovery_configuration=None): |
|
261
|
|
|
""" |
|
262
|
|
|
register a server to discovery server |
|
263
|
|
|
if discovery_configuration is provided, the newer register_server2 service call is used |
|
264
|
|
|
""" |
|
265
|
1 |
|
serv = ua.RegisteredServer() |
|
266
|
1 |
|
serv.ServerUri = server.application_uri |
|
267
|
1 |
|
serv.ProductUri = server.product_uri |
|
268
|
1 |
|
serv.DiscoveryUrls = [server.endpoint.geturl()] |
|
269
|
1 |
|
serv.ServerType = server.application_type |
|
270
|
1 |
|
serv.ServerNames = [ua.LocalizedText(server.name)] |
|
271
|
1 |
|
serv.IsOnline = True |
|
272
|
1 |
|
if discovery_configuration: |
|
273
|
|
|
params = ua.RegisterServer2Parameters() |
|
274
|
|
|
params.Server = serv |
|
275
|
|
|
params.DiscoveryConfiguration = discovery_configuration |
|
276
|
|
|
return self.uaclient.register_server2(params) |
|
277
|
|
|
else: |
|
278
|
1 |
|
return self.uaclient.register_server(serv) |
|
279
|
|
|
|
|
280
|
1 |
|
def find_servers(self, uris=None): |
|
281
|
|
|
""" |
|
282
|
|
|
send a FindServer request to the server. The answer should be a list of |
|
283
|
|
|
servers the server knows about |
|
284
|
|
|
A list of uris can be provided, only server having matching uris will be returned |
|
285
|
|
|
""" |
|
286
|
1 |
|
if uris is None: |
|
287
|
1 |
|
uris = [] |
|
288
|
1 |
|
params = ua.FindServersParameters() |
|
289
|
1 |
|
params.EndpointUrl = self.server_url.geturl() |
|
290
|
1 |
|
params.ServerUris = uris |
|
291
|
1 |
|
return self.uaclient.find_servers(params) |
|
292
|
|
|
|
|
293
|
1 |
|
def find_servers_on_network(self): |
|
294
|
|
|
params = ua.FindServersOnNetworkParameters() |
|
295
|
|
|
return self.uaclient.find_servers_on_network(params) |
|
296
|
|
|
|
|
297
|
1 |
|
def create_session(self): |
|
298
|
1 |
|
desc = ua.ApplicationDescription() |
|
299
|
1 |
|
desc.ApplicationUri = self.application_uri |
|
300
|
1 |
|
desc.ProductUri = self.product_uri |
|
301
|
1 |
|
desc.ApplicationName = ua.LocalizedText(self.name) |
|
302
|
1 |
|
desc.ApplicationType = ua.ApplicationType.Client |
|
303
|
|
|
|
|
304
|
1 |
|
params = ua.CreateSessionParameters() |
|
305
|
1 |
|
nonce = utils.create_nonce(32) # at least 32 random bytes for server to prove possession of private key (specs part 4, 5.6.2.2) |
|
306
|
1 |
|
params.ClientNonce = nonce |
|
307
|
1 |
|
params.ClientCertificate = self.security_policy.client_certificate |
|
308
|
1 |
|
params.ClientDescription = desc |
|
309
|
1 |
|
params.EndpointUrl = self.server_url.geturl() |
|
310
|
1 |
|
params.SessionName = self.description + " Session" + str(self._session_counter) |
|
311
|
1 |
|
params.RequestedSessionTimeout = 3600000 |
|
312
|
1 |
|
params.MaxResponseMessageSize = 0 # means no max size |
|
313
|
1 |
|
response = self.uaclient.create_session(params) |
|
314
|
1 |
|
self.security_policy.asymmetric_cryptography.verify(self.security_policy.client_certificate + nonce, response.ServerSignature.Signature) |
|
315
|
1 |
|
self._server_nonce = response.ServerNonce |
|
316
|
1 |
|
if not self.security_policy.server_certificate: |
|
317
|
1 |
|
self.security_policy.server_certificate = response.ServerCertificate |
|
318
|
|
|
elif self.security_policy.server_certificate != response.ServerCertificate: |
|
319
|
|
|
raise UaError("Server certificate mismatch") |
|
320
|
|
|
# remember PolicyId's: we will use them in activate_session() |
|
321
|
1 |
|
ep = Client.find_endpoint(response.ServerEndpoints, self.security_policy.Mode, self.security_policy.URI) |
|
322
|
1 |
|
self._policy_ids = ep.UserIdentityTokens |
|
323
|
1 |
|
self.session_timeout = response.RevisedSessionTimeout |
|
324
|
1 |
|
self.keepalive = KeepAlive(self, min(self.session_timeout, self.secure_channel_timeout) * 0.7) # 0.7 is from spec |
|
325
|
1 |
|
self.keepalive.start() |
|
326
|
1 |
|
return response |
|
327
|
|
|
|
|
328
|
1 |
|
def server_policy_id(self, token_type, default): |
|
329
|
|
|
""" |
|
330
|
|
|
Find PolicyId of server's UserTokenPolicy by token_type. |
|
331
|
|
|
Return default if there's no matching UserTokenPolicy. |
|
332
|
|
|
""" |
|
333
|
1 |
|
for policy in self._policy_ids: |
|
334
|
1 |
|
if policy.TokenType == token_type: |
|
335
|
1 |
|
return policy.PolicyId |
|
336
|
1 |
|
return default |
|
337
|
|
|
|
|
338
|
1 |
|
def server_policy_uri(self, token_type): |
|
339
|
|
|
""" |
|
340
|
|
|
Find SecurityPolicyUri of server's UserTokenPolicy by token_type. |
|
341
|
|
|
If SecurityPolicyUri is empty, use default SecurityPolicyUri |
|
342
|
|
|
of the endpoint |
|
343
|
|
|
""" |
|
344
|
|
|
result = '' |
|
345
|
|
|
for policy in self._policy_ids: |
|
346
|
|
|
if policy.TokenType == token_type: |
|
347
|
|
|
result = policy.SecurityPolicyUri |
|
348
|
|
|
break |
|
349
|
|
|
if result: |
|
350
|
|
|
return result |
|
351
|
|
|
else: |
|
352
|
|
|
return self.security_policy.URI |
|
353
|
|
|
|
|
354
|
1 |
|
def activate_session(self, username=None, password=None, certificate=None): |
|
355
|
|
|
""" |
|
356
|
|
|
Activate session using either username and password or private_key |
|
357
|
|
|
""" |
|
358
|
1 |
|
params = ua.ActivateSessionParameters() |
|
359
|
1 |
|
challenge = self.security_policy.server_certificate + self._server_nonce |
|
360
|
1 |
|
params.ClientSignature.Algorithm = b"http://www.w3.org/2000/09/xmldsig#rsa-sha1" |
|
361
|
1 |
|
params.ClientSignature.Signature = self.security_policy.asymmetric_cryptography.signature(challenge) |
|
362
|
1 |
|
params.LocaleIds.append("en") |
|
363
|
1 |
|
if not username and not certificate: |
|
364
|
1 |
|
params.UserIdentityToken = ua.AnonymousIdentityToken() |
|
365
|
1 |
|
params.UserIdentityToken.PolicyId = self.server_policy_id(ua.UserTokenType.Anonymous, b"anonymous") |
|
366
|
1 |
|
elif certificate: |
|
367
|
|
|
params.UserIdentityToken = ua.X509IdentityToken() |
|
368
|
|
|
params.UserIdentityToken.PolicyId = self.server_policy_id(ua.UserTokenType.Certificate, b"certificate_basic256") |
|
369
|
|
|
params.UserIdentityToken.CertificateData = uacrypto.der_from_x509(certificate) |
|
370
|
|
|
# specs part 4, 5.6.3.1: the data to sign is created by appending |
|
371
|
|
|
# the last serverNonce to the serverCertificate |
|
372
|
|
|
sig = uacrypto.sign_sha1(self.user_private_key, challenge) |
|
373
|
|
|
params.UserTokenSignature = ua.SignatureData() |
|
374
|
|
|
params.UserTokenSignature.Algorithm = b"http://www.w3.org/2000/09/xmldsig#rsa-sha1" |
|
375
|
|
|
params.UserTokenSignature.Signature = sig |
|
376
|
|
|
else: |
|
377
|
1 |
|
params.UserIdentityToken = ua.UserNameIdentityToken() |
|
378
|
1 |
|
params.UserIdentityToken.UserName = username |
|
379
|
1 |
|
if self.server_url.password: |
|
380
|
|
|
pubkey = uacrypto.x509_from_der(self.security_policy.server_certificate).public_key() |
|
381
|
|
|
# see specs part 4, 7.36.3: if the token is encrypted, password |
|
382
|
|
|
# shall be converted to UTF-8 and serialized with server nonce |
|
383
|
|
|
etoken = ua.pack_bytes(bytes(password, "utf8") + self._server_nonce) |
|
384
|
|
|
(data, uri) = security_policies.encrypt_asymmetric(pubkey, |
|
385
|
|
|
etoken, |
|
386
|
|
|
self.server_policy_uri(ua.UserTokenType.UserName)) |
|
387
|
|
|
params.UserIdentityToken.Password = data |
|
388
|
|
|
params.UserIdentityToken.EncryptionAlgorithm = uri |
|
389
|
1 |
|
params.UserIdentityToken.PolicyId = self.server_policy_id(ua.UserTokenType.UserName, b"username_basic256") |
|
390
|
1 |
|
return self.uaclient.activate_session(params) |
|
391
|
|
|
|
|
392
|
1 |
|
def close_session(self): |
|
393
|
|
|
""" |
|
394
|
|
|
Close session |
|
395
|
|
|
""" |
|
396
|
1 |
|
if self.keepalive: |
|
397
|
1 |
|
self.keepalive.stop() |
|
398
|
1 |
|
return self.uaclient.close_session(True) |
|
399
|
|
|
|
|
400
|
1 |
|
def get_root_node(self): |
|
401
|
1 |
|
return self.get_node(ua.TwoByteNodeId(ua.ObjectIds.RootFolder)) |
|
402
|
|
|
|
|
403
|
1 |
|
def get_objects_node(self): |
|
404
|
1 |
|
return self.get_node(ua.TwoByteNodeId(ua.ObjectIds.ObjectsFolder)) |
|
405
|
|
|
|
|
406
|
1 |
|
def get_server_node(self): |
|
407
|
1 |
|
return self.get_node(ua.FourByteNodeId(ua.ObjectIds.Server)) |
|
408
|
|
|
|
|
409
|
1 |
|
def get_node(self, nodeid): |
|
410
|
|
|
""" |
|
411
|
|
|
Get node using NodeId object or a string representing a NodeId |
|
412
|
|
|
""" |
|
413
|
1 |
|
return Node(self.uaclient, nodeid) |
|
414
|
|
|
|
|
415
|
1 |
|
def create_subscription(self, period, handler): |
|
416
|
|
|
""" |
|
417
|
|
|
Create a subscription. |
|
418
|
|
|
returns a Subscription object which allow |
|
419
|
|
|
to subscribe to events or data on server |
|
420
|
|
|
handler argument is a class with data_change and/or event methods. |
|
421
|
|
|
These methods will be called when notfication from server are received. |
|
422
|
|
|
See example-client.py. |
|
423
|
|
|
Do not do expensive/slow or network operation from these methods |
|
424
|
|
|
since they are called directly from receiving thread. This is a design choice, |
|
425
|
|
|
start another thread if you need to do such a thing. |
|
426
|
|
|
""" |
|
427
|
1 |
|
params = ua.CreateSubscriptionParameters() |
|
428
|
1 |
|
params.RequestedPublishingInterval = period |
|
429
|
1 |
|
params.RequestedLifetimeCount = 3000 |
|
430
|
1 |
|
params.RequestedMaxKeepAliveCount = 10000 |
|
431
|
1 |
|
params.MaxNotificationsPerPublish = 10000 |
|
432
|
1 |
|
params.PublishingEnabled = True |
|
433
|
1 |
|
params.Priority = 0 |
|
434
|
1 |
|
return Subscription(self.uaclient, params, handler) |
|
435
|
|
|
|
|
436
|
1 |
|
def get_namespace_array(self): |
|
437
|
1 |
|
ns_node = self.get_node(ua.NodeId(ua.ObjectIds.Server_NamespaceArray)) |
|
438
|
1 |
|
return ns_node.get_value() |
|
439
|
|
|
|
|
440
|
1 |
|
def get_namespace_index(self, uri): |
|
441
|
1 |
|
uries = self.get_namespace_array() |
|
442
|
1 |
|
return uries.index(uri) |
|
443
|
|
|
|
|
444
|
1 |
|
def delete_nodes(self, nodes, recursive=False): |
|
445
|
1 |
|
return delete_nodes(self.uaclient, nodes, recursive) |
|
446
|
|
|
|
|
447
|
|
|
|
FreeOpcUa /
python-opcua
