opcua.Client.connect() - Code Metrics - Inspection of "add support for find_servers_on_network to client..." - FreeOpcUa/python-opcua - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — dev ( a35960...17cd27 )

by Olivier

created 2015-12-02 20:53 UTC

opcua.Client.connect() A

↳ Parent: opcua.Client

Complexity

Conditions

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	6
CRAP Score	1

Metric	Value
dl	0
loc	10
ccs	6
cts	6
cp	1
rs	9.4286
cc	1
crap	1

from __future__ import division  # support for python2
import os
from threading import Thread, Condition
import logging
try:
    from urllib.parse import urlparse
except ImportError:  # support for python2
    from urlparse import urlparse

from opcua import uaprotocol as ua
from opcua import BinaryClient, Node, Subscription
from opcua import utils
from opcua import uacrypto


class KeepAlive(Thread):

    """
    Used by Client to keep session opened.
    OPCUA defines timeout both for sessions and secure channel
    """

    def __init__(self, client, timeout):
        Thread.__init__(self)
        self.logger = logging.getLogger(__name__)
        if timeout == 0:  # means no timeout bu we do not trust such servers
            timeout = 360000
        self.timeout = timeout
        self.client = client
        self._dostop = False
        self._cond = Condition()

    def run(self):
        self.logger.debug("starting keepalive thread with period of %s milliseconds", self.timeout)
        server_state = self.client.get_node(ua.FourByteNodeId(ua.ObjectIds.Server_ServerStatus_State))
        while not self._dostop:
            with self._cond:
                self._cond.wait(self.timeout / 1000)
            if self._dostop:
                break
            self.logger.debug("renewing channel")
            self.client.open_secure_channel(renew=True)
            val = server_state.get_value()
            self.logger.debug("server state is: %s ", val)
        self.logger.debug("keepalive thread has stopped")

    def stop(self):
        self.logger.debug("stoping keepalive thread")
        with self._cond:
            self._cond.notify_all()
        self._dostop = True


class Client(object):

    """
    High level client to connect to an OPC-UA server.
    This class makes it easy to connect and browse address space.
    It attemps to expose as much functionality as possible
    but if you want to do to special things you will probably need
    to work with the BinaryClient object, available as self.bclient
    which offers a raw OPC-UA interface.
    """

    def __init__(self, url, timeout=1):
        """
        used url argument to connect to server.
        if you are unsure of url, write at least hostname and port
        and call get_endpoints
        timeout is the timeout to get an answer for requests to server
        public member of this call are available to be set by API users

        """
        self.logger = logging.getLogger(__name__)
        self.server_url = urlparse(url)
        self.name = "Pure Python Client"
        self.description = self.name
        self.application_uri = "urn:freeopcua:client"
        self.product_uri = "urn:freeopcua.github.no:client"
        self.security_policy_uri = "http://opcfoundation.org/UA/SecurityPolicy#None"
        self.security_mode = ua.MessageSecurityMode.None_
        self.secure_channel_id = None
        self.default_timeout = 3600000
        self.secure_channel_timeout = self.default_timeout
        self.session_timeout = self.default_timeout
        self._policy_ids = []
        self.server_certificate = ""
        self.client_certificate = ""
        self.private_key = ""
        self.bclient = BinaryClient(timeout)
        self._nonce = None
        self._session_counter = 1
        self.keepalive = None

    def load_client_certificate(self, path):
        """
        load our certificate from file, either pem or der
        """
        _, ext = os.path.splitext(path)
        with open(path, "br") as f:
            self.client_certificate = f.read()
        if ext == ".pem":
            self.client_certificate = uacrypto.dem_to_der(self.client_certificate)

    def load_private_key(self, path):
        with open(path, "br") as f:
            self.private_key = f.read()

    def get_server_endpoints(self):
        """
        Connect, ask server for endpoints, and disconnect
        """
        self.connect_socket()
        self.send_hello()
        self.open_secure_channel()
        endpoints = self.get_endpoints()
        self.close_secure_channel()
        self.disconnect_socket()
        return endpoints

    def find_all_servers(self):
        """
        Connect, ask server for a list of known servers, and disconnect
        """
        self.connect_socket()
        self.send_hello()
        self.open_secure_channel()
        servers = self.find_servers()
        self.close_secure_channel()
        self.disconnect_socket()
        return servers

    def find_all_servers_on_network(self):
        """
        Connect, ask server for a list of known servers on network, and disconnect
        """
        self.connect_socket()
        self.send_hello()
        self.open_secure_channel()
        servers = self.find_servers_on_network()
        self.close_secure_channel()
        self.disconnect_socket()
        return servers



    def connect(self):
        """
        High level method
        Connect, create and activate session
        """
        self.connect_socket()
        self.send_hello()
        self.open_secure_channel()
        self.create_session()
        self.activate_session(username=self.server_url.username, password=self.server_url.password, certificate=self.client_certificate)

    def disconnect(self):
        """
        High level method
        Close session, secure channel and socket
        """
        self.close_session()
        self.close_secure_channel()
        self.disconnect_socket()

    def connect_socket(self):
        """
        connect to socket defined in url
        """
        self.bclient.connect_socket(self.server_url.hostname, self.server_url.port)

    def disconnect_socket(self):
        self.bclient.disconnect_socket()

    def send_hello(self):
        """
        Send OPC-UA hello to server
        """
        ack = self.bclient.send_hello(self.server_url.geturl())
        # FIXME check ack

    def open_secure_channel(self, renew=False):
        """
        Open secure channel, if renew is True, renew channel
        """
        params = ua.OpenSecureChannelParameters()
        params.ClientProtocolVersion = 0
        params.RequestType = ua.SecurityTokenRequestType.Issue
        if renew:
            params.RequestType = ua.SecurityTokenRequestType.Renew
        params.SecurityMode = self.security_mode
        params.RequestedLifetime = self.secure_channel_timeout
        params.ClientNonce = '\x00'
        result = self.bclient.open_secure_channel(params)
        self.secure_channel_timeout = result.SecurityToken.RevisedLifetime

    def close_secure_channel(self):
        return self.bclient.close_secure_channel()

    def get_endpoints(self):
        params = ua.GetEndpointsParameters()
        params.EndpointUrl = self.server_url.geturl()
        return self.bclient.get_endpoints(params)

    def find_servers(self):
        params = ua.FindServersParameters()
        return self.bclient.find_servers(params)

    def find_servers_on_network(self):
        params = ua.FindServersOnNetworkParameters()
        return self.bclient.find_servers_on_network(params)

    def create_session(self):
        desc = ua.ApplicationDescription()
        desc.ApplicationUri = self.application_uri
        desc.ProductUri = self.product_uri
        desc.ApplicationName = ua.LocalizedText(self.name)
        desc.ApplicationType = ua.ApplicationType.Client

        params = ua.CreateSessionParameters()
        params.ClientNonce = utils.create_nonce()
        params.ClientCertificate = b''
        params.ClientDescription = desc
        params.EndpointUrl = self.server_url.geturl()
        params.SessionName = self.description + " Session" + str(self._session_counter)
        params.RequestedSessionTimeout = 3600000
        params.MaxResponseMessageSize = 0  # means no max size
        params.ClientCertificate = self.client_certificate
        response = self.bclient.create_session(params)
        self.server_certificate = response.ServerCertificate
        for ep in response.ServerEndpoints:
            if ep.SecurityMode == self.security_mode:
                # remember PolicyId's: we will use them in activate_session()
                self._policy_ids = ep.UserIdentityTokens
        self.session_timeout = response.RevisedSessionTimeout
        self.keepalive = KeepAlive(self, min(self.session_timeout, self.secure_channel_timeout) * 0.7)  # 0.7 is from spec
        self.keepalive.start()
        return response

    def activate_session(self, username=None, password=None, certificate=None):
        """
        Activate session using either username and password or private_key
        """
        params = ua.ActivateSessionParameters()
        params.LocaleIds.append("en")
        if not username and not certificate:
            params.UserIdentityToken = ua.AnonymousIdentityToken()
            params.UserIdentityToken.PolicyId = b"anonymous" 
        elif certificate:
            params.UserIdentityToken = ua.X509IdentityToken()
            params.UserIdentityToken.PolicyId = b"certificate_basic256"  
            params.UserIdentityToken.CertificateData = certificate
            sig = uacrypto.sign_sha1(self.private_key, certificate)
            params.UserTokenSignature = ua.SignatureData()
            params.UserTokenSignature.Algorithm = b"http://www.w3.org/2000/09/xmldsig#rsa-sha1"
            params.UserTokenSignature.Signature = sig
        else:
            params.UserIdentityToken = ua.UserNameIdentityToken()
            params.UserIdentityToken.UserName = username 
            if self.server_url.password:
                pubkey = uacrypto.pubkey_from_dercert(self.server_certificate)
                data = uacrypto.encrypt_rsa_oaep(pubkey, bytes(password, "utf8"))
                params.UserIdentityToken.Password = data
            params.UserIdentityToken.PolicyId = b"username_basic256" 
            params.UserIdentityToken.EncryptionAlgorithm = 'http://www.w3.org/2001/04/xmlenc#rsa-oaep'
        return self.bclient.activate_session(params)

    def close_session(self):
        """
        Close session
        """
        if self.keepalive:
            self.keepalive.stop()
        return self.bclient.close_session(True)

    def get_root_node(self):
        return self.get_node(ua.TwoByteNodeId(ua.ObjectIds.RootFolder))

    def get_objects_node(self):
        return self.get_node(ua.TwoByteNodeId(ua.ObjectIds.ObjectsFolder))

    def get_server_node(self):
        return self.get_node(ua.TwoByteNodeId(ua.ObjectIds.Server))

    def get_node(self, nodeid):
        """
        Get node using NodeId object or a string representing a NodeId
        """
        return Node(self.bclient, nodeid)

    def create_subscription(self, period, handler):
        """
        Create a subscription.
        returns a Subscription object which allow
        to subscribe to events or data on server
        handler argument is a class with data_change and/or event methods.
        These methods will be called when notfication from server are received.
        See example-client.py.
        Do not do expensive/slow or network operation from these methods 
        since they are called directly from receiving thread. This is a design choice,
        start another thread if you need to do such a thing.
        """
        params = ua.CreateSubscriptionParameters()
        params.RequestedPublishingInterval = period
        params.RequestedLifetimeCount = 3000
        params.RequestedMaxKeepAliveCount = 10000
        params.MaxNotificationsPerPublish = 4294967295
        params.PublishingEnabled = True
        params.Priority = 0
        return Subscription(self.bclient, params, handler)

    def get_namespace_array(self):
        ns_node = self.get_node(ua.NodeId(ua.ObjectIds.Server_NamespaceArray))
        return ns_node.get_value()

    def get_namespace_index(self, uri):
        uries = self.get_namespace_array()
        return uries.index(uri)


1	1	from __future__ import division # support for python2
2	1	import os
3	1	from threading import Thread, Condition
4	1	import logging
5	1	try:
6	1	from urllib.parse import urlparse
7		except ImportError: # support for python2
8		from urlparse import urlparse
9
10	1	from opcua import uaprotocol as ua
11	1	from opcua import BinaryClient, Node, Subscription
12	1	from opcua import utils
13	1	from opcua import uacrypto
14
15
16	1	class KeepAlive(Thread):
17
18		"""
19		Used by Client to keep session opened.
20		OPCUA defines timeout both for sessions and secure channel
21		"""
22
23	1	def __init__(self, client, timeout):
24	1	Thread.__init__(self)
25	1	self.logger = logging.getLogger(__name__)
26	1	if timeout == 0: # means no timeout bu we do not trust such servers
27		timeout = 360000
28	1	self.timeout = timeout
29	1	self.client = client
30	1	self._dostop = False
31	1	self._cond = Condition()
32
33	1	def run(self):
34	1	self.logger.debug("starting keepalive thread with period of %s milliseconds", self.timeout)
35	1	server_state = self.client.get_node(ua.FourByteNodeId(ua.ObjectIds.Server_ServerStatus_State))
36	1	while not self._dostop:
37	1	with self._cond:
38	1	self._cond.wait(self.timeout / 1000)
39	1	if self._dostop:
40	1	break
41		self.logger.debug("renewing channel")
42		self.client.open_secure_channel(renew=True)
43		val = server_state.get_value()
44		self.logger.debug("server state is: %s ", val)
45	1	self.logger.debug("keepalive thread has stopped")
46
47	1	def stop(self):
48	1	self.logger.debug("stoping keepalive thread")
49	1	with self._cond:
50	1	self._cond.notify_all()
51	1	self._dostop = True
52
53
54	1	class Client(object):
55
56		"""
57		High level client to connect to an OPC-UA server.
58		This class makes it easy to connect and browse address space.
59		It attemps to expose as much functionality as possible
60		but if you want to do to special things you will probably need
61		to work with the BinaryClient object, available as self.bclient
62		which offers a raw OPC-UA interface.
63		"""
64
65	1	def __init__(self, url, timeout=1):
66		"""
67		used url argument to connect to server.
68		if you are unsure of url, write at least hostname and port
69		and call get_endpoints
70		timeout is the timeout to get an answer for requests to server
71		public member of this call are available to be set by API users
72
73		"""
74	1	self.logger = logging.getLogger(__name__)
75	1	self.server_url = urlparse(url)
76	1	self.name = "Pure Python Client"
77	1	self.description = self.name
78	1	self.application_uri = "urn:freeopcua:client"
79	1	self.product_uri = "urn:freeopcua.github.no:client"
80	1	self.security_policy_uri = "http://opcfoundation.org/UA/SecurityPolicy#None"
81	1	self.security_mode = ua.MessageSecurityMode.None_
82	1	self.secure_channel_id = None
83	1	self.default_timeout = 3600000
84	1	self.secure_channel_timeout = self.default_timeout
85	1	self.session_timeout = self.default_timeout
86	1	self._policy_ids = []
87	1	self.server_certificate = ""
88	1	self.client_certificate = ""
89	1	self.private_key = ""
90	1	self.bclient = BinaryClient(timeout)
91	1	self._nonce = None
92	1	self._session_counter = 1
93	1	self.keepalive = None
94
95	1	def load_client_certificate(self, path):
96		"""
97		load our certificate from file, either pem or der
98		"""
99		_, ext = os.path.splitext(path)
100		with open(path, "br") as f:
101		self.client_certificate = f.read()
102		if ext == ".pem":
103		self.client_certificate = uacrypto.dem_to_der(self.client_certificate)
104
105	1	def load_private_key(self, path):
106		with open(path, "br") as f:
107		self.private_key = f.read()
108
109	1	def get_server_endpoints(self):
110		"""
111		Connect, ask server for endpoints, and disconnect
112		"""
113		self.connect_socket()
114		self.send_hello()
115		self.open_secure_channel()
116		endpoints = self.get_endpoints()
117		self.close_secure_channel()
118		self.disconnect_socket()
119		return endpoints
120
121	1	def find_all_servers(self):
122		"""
123		Connect, ask server for a list of known servers, and disconnect
124		"""
125		self.connect_socket()
126		self.send_hello()
127		self.open_secure_channel()
128		servers = self.find_servers()
129		self.close_secure_channel()
130		self.disconnect_socket()
131		return servers
132
133	1	def find_all_servers_on_network(self):
134		"""
135		Connect, ask server for a list of known servers on network, and disconnect
136		"""
137		self.connect_socket()
138		self.send_hello()
139		self.open_secure_channel()
140		servers = self.find_servers_on_network()
141		self.close_secure_channel()
142		self.disconnect_socket()
143		return servers
144
145
146
147	1	def connect(self):
148		"""
149		High level method
150		Connect, create and activate session
151		"""
152	1	self.connect_socket()
153	1	self.send_hello()
154	1	self.open_secure_channel()
155	1	self.create_session()
156	1	self.activate_session(username=self.server_url.username, password=self.server_url.password, certificate=self.client_certificate)
157
158	1	def disconnect(self):
159		"""
160		High level method
161		Close session, secure channel and socket
162		"""
163	1	self.close_session()
164	1	self.close_secure_channel()
165	1	self.disconnect_socket()
166
167	1	def connect_socket(self):
168		"""
169		connect to socket defined in url
170		"""
171	1	self.bclient.connect_socket(self.server_url.hostname, self.server_url.port)
172
173	1	def disconnect_socket(self):
174	1	self.bclient.disconnect_socket()
175
176	1	def send_hello(self):
177		"""
178		Send OPC-UA hello to server
179		"""
180	1	ack = self.bclient.send_hello(self.server_url.geturl())
181		# FIXME check ack
182
183	1	def open_secure_channel(self, renew=False):
184		"""
185		Open secure channel, if renew is True, renew channel
186		"""
187	1	params = ua.OpenSecureChannelParameters()
188	1	params.ClientProtocolVersion = 0
189	1	params.RequestType = ua.SecurityTokenRequestType.Issue
190	1	if renew:
191		params.RequestType = ua.SecurityTokenRequestType.Renew
192	1	params.SecurityMode = self.security_mode
193	1	params.RequestedLifetime = self.secure_channel_timeout
194	1	params.ClientNonce = '\x00'
195	1	result = self.bclient.open_secure_channel(params)
196	1	self.secure_channel_timeout = result.SecurityToken.RevisedLifetime
197
198	1	def close_secure_channel(self):
199	1	return self.bclient.close_secure_channel()
200
201	1	def get_endpoints(self):
202	1	params = ua.GetEndpointsParameters()
203	1	params.EndpointUrl = self.server_url.geturl()
204	1	return self.bclient.get_endpoints(params)
205
206	1	def find_servers(self):
207		params = ua.FindServersParameters()
208		return self.bclient.find_servers(params)
209
210	1	def find_servers_on_network(self):
211		params = ua.FindServersOnNetworkParameters()
212		return self.bclient.find_servers_on_network(params)
213
214	1	def create_session(self):
215	1	desc = ua.ApplicationDescription()
216	1	desc.ApplicationUri = self.application_uri
217	1	desc.ProductUri = self.product_uri
218	1	desc.ApplicationName = ua.LocalizedText(self.name)
219	1	desc.ApplicationType = ua.ApplicationType.Client
220
221	1	params = ua.CreateSessionParameters()
222	1	params.ClientNonce = utils.create_nonce()
223	1	params.ClientCertificate = b''
224	1	params.ClientDescription = desc
225	1	params.EndpointUrl = self.server_url.geturl()
226	1	params.SessionName = self.description + " Session" + str(self._session_counter)
227	1	params.RequestedSessionTimeout = 3600000
228	1	params.MaxResponseMessageSize = 0 # means no max size
229	1	params.ClientCertificate = self.client_certificate
230	1	response = self.bclient.create_session(params)
231	1	self.server_certificate = response.ServerCertificate
232	1	for ep in response.ServerEndpoints:
233	1	if ep.SecurityMode == self.security_mode:
234		# remember PolicyId's: we will use them in activate_session()
235	1	self._policy_ids = ep.UserIdentityTokens
236	1	self.session_timeout = response.RevisedSessionTimeout
237	1	self.keepalive = KeepAlive(self, min(self.session_timeout, self.secure_channel_timeout) * 0.7) # 0.7 is from spec
238	1	self.keepalive.start()
239	1	return response
240
241	1	def activate_session(self, username=None, password=None, certificate=None):
242		"""
243		Activate session using either username and password or private_key
244		"""
245	1	params = ua.ActivateSessionParameters()
246	1	params.LocaleIds.append("en")
247	1	if not username and not certificate:
248	1	params.UserIdentityToken = ua.AnonymousIdentityToken()
249	1	params.UserIdentityToken.PolicyId = b"anonymous"
250	1	elif certificate:
251		params.UserIdentityToken = ua.X509IdentityToken()
252		params.UserIdentityToken.PolicyId = b"certificate_basic256"
253		params.UserIdentityToken.CertificateData = certificate
254		sig = uacrypto.sign_sha1(self.private_key, certificate)
255		params.UserTokenSignature = ua.SignatureData()
256		params.UserTokenSignature.Algorithm = b"http://www.w3.org/2000/09/xmldsig#rsa-sha1"
257		params.UserTokenSignature.Signature = sig
258		else:
259	1	params.UserIdentityToken = ua.UserNameIdentityToken()
260	1	params.UserIdentityToken.UserName = username
261	1	if self.server_url.password:
262		pubkey = uacrypto.pubkey_from_dercert(self.server_certificate)
263		data = uacrypto.encrypt_rsa_oaep(pubkey, bytes(password, "utf8"))
264		params.UserIdentityToken.Password = data
265	1	params.UserIdentityToken.PolicyId = b"username_basic256"
266	1	params.UserIdentityToken.EncryptionAlgorithm = 'http://www.w3.org/2001/04/xmlenc#rsa-oaep'
267	1	return self.bclient.activate_session(params)
268
269	1	def close_session(self):
270		"""
271		Close session
272		"""
273	1	if self.keepalive:
274	1	self.keepalive.stop()
275	1	return self.bclient.close_session(True)
276
277	1	def get_root_node(self):
278	1	return self.get_node(ua.TwoByteNodeId(ua.ObjectIds.RootFolder))
279
280	1	def get_objects_node(self):
281	1	return self.get_node(ua.TwoByteNodeId(ua.ObjectIds.ObjectsFolder))
282
283	1	def get_server_node(self):
284	1	return self.get_node(ua.TwoByteNodeId(ua.ObjectIds.Server))
285
286	1	def get_node(self, nodeid):
287		"""
288		Get node using NodeId object or a string representing a NodeId
289		"""
290	1	return Node(self.bclient, nodeid)
291
292	1	def create_subscription(self, period, handler):
293		"""
294		Create a subscription.
295		returns a Subscription object which allow
296		to subscribe to events or data on server
297		handler argument is a class with data_change and/or event methods.
298		These methods will be called when notfication from server are received.
299		See example-client.py.
300		Do not do expensive/slow or network operation from these methods
301		since they are called directly from receiving thread. This is a design choice,
302		start another thread if you need to do such a thing.
303		"""
304	1	params = ua.CreateSubscriptionParameters()
305	1	params.RequestedPublishingInterval = period
306	1	params.RequestedLifetimeCount = 3000
307	1	params.RequestedMaxKeepAliveCount = 10000
308	1	params.MaxNotificationsPerPublish = 4294967295
309	1	params.PublishingEnabled = True
310	1	params.Priority = 0
311	1	return Subscription(self.bclient, params, handler)
312
313	1	def get_namespace_array(self):
314	1	ns_node = self.get_node(ua.NodeId(ua.ObjectIds.Server_NamespaceArray))
315	1	return ns_node.get_value()
316
317	1	def get_namespace_index(self, uri):
318	1	uries = self.get_namespace_array()
319		return uries.index(uri)
320

FreeOpcUa / python-opcua

Push — dev ( a35960...17cd27 )

opcua.Client.connect() A

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