Source Code for Package ndg.xacml.core

  1  """NDG XACML core package  
  2   
  3  NERC DataGrid 
  4  """ 
  5  __author__ = "P J Kershaw" 
  6  __date__ = "16/03/10" 
  7  __copyright__ = "(C) 2010 Science and Technology Facilities Council" 
  8  __contact__ = "Philip.Kershaw@stfc.ac.uk" 
  9  __license__ = "BSD - see LICENSE file in top-level directory" 
 10  __contact__ = "Philip.Kershaw@stfc.ac.uk" 
 11  __revision__ = "$Id: __init__.py 8010 2012-01-30 16:24:06Z rwilkinson $" 
 12  from ndg.xacml.utils import TypedList 
 13   
 14       
 15 -class XacmlCoreBase(object): 
 16      """Base class for all XACML types 
 17       
 18      @cvar XACML_1_0_NS_PREFIX: XACML version 1.0 namespace prefix 
 19      @type XACML_1_0_NS_PREFIX: string 
 20      @cvar XACML_2_0_NS_PREFIX: XACML version 2.0 namespace prefix 
 21      @type XACML_2_0_NS_PREFIX: string 
 22      @cvar XMLNS: list of valid XACML namespaces 
 23      @type XMLNS: tuple 
 24      @cvar ELEMENT_LOCAL_NAME: XML element local name for the given type 
 25      @type ELEMENT_LOCAL_NAME: NoneType but implement as string in derived  
 26      classes 
 27       
 28      @ivar __xmlns: XML namespace for the XACML type 
 29      @type __xmlns: NoneType / basestring 
 30           
 31      @ivar __elem: XML element  
 32      @type __elem: NoneType / dependent on Python XML parser used 
 33      """ 
 34      XACML_1_0_NS_PREFIX = "urn:oasis:names:tc:xacml:1.0" 
 35      XACML_2_0_NS_PREFIX = "urn:oasis:names:tc:xacml:2.0" 
 36       
 37      XMLNS = (XACML_1_0_NS_PREFIX, XACML_2_0_NS_PREFIX) 
 38       
 39      __slots__ = ('__xmlns', '__reader', '__writer', '__elem') 
 40   
 41      ELEMENT_LOCAL_NAME = None 
 42       
 43 -    def __init__(self): 
 44          """Element local name check makes this a virtual method 
 45           
 46          @raise NotImplementedError: derived classes must set  
 47          ELEMENT_LOCAL_NAME to a string 
 48          """ 
 49          self.__xmlns = None 
 50          self.__elem = None 
 51          self.__reader = None 
 52          self.__writer = None 
 53           
 54          if not isinstance(self.__class__.ELEMENT_LOCAL_NAME, basestring): 
 55              raise NotImplementedError('"ELEMENT_LOCAL_NAME" must be defined in ' 
 56                                        'a derived class') 
 57           
 58 -    def _getXmlns(self): 
 59          """Get XML Namespace for this XACML type 
 60          @return: the XML namespace set 
 61          @rtype: basestring/NoneType         
 62          """ 
 63          return self.__xmlns 
 64   
 65 -    def _setXmlns(self, value): 
 66          """Set XML Namespace for this XACML type 
 67          @param value: the XML namespace to set 
 68          @type value: basestring/NoneType                  
 69          """ 
 70          if not isinstance(value, basestring): 
 71              raise TypeError('Expecting string type for "xmlns" ' 
 72                              'attribute; got %r' % type(value)) 
 73          self.__xmlns = value 
 74   
 75      xmlns = property(_getXmlns, _setXmlns,  
 76                       doc="XML Namespace for policy the document") 
 77       
 78      @property 
 79 -    def isValidXmlns(self): 
 80          """Check XML namespace fits with the known XACML namespaces 
 81          @return: True if valid, False otherwise 
 82          @rtype: bool 
 83          """ 
 84          return self.xmlns in XacmlCoreBase.XMLNS 
 85           
 86      @property 
 87 -    def elem(self): 
 88          """XML Node for as represented by parser/writer specified with the  
 89          reader/writer attributes.  Readers of context elements should set this 
 90          element if a policy uses AttributeSelectors to do XPath queries into 
 91          the request context 
 92          """ 
 93          return self.__elem 
 94           
 95      @elem.setter 
 96 -    def elem(self, value): 
 97          """"XML Node for as represented by parser/writer specified with the  
 98          reader/writer attributes 
 99           
100          @param value: XML node instance 
101          @type value: type (governed by reader/writer set for this XACML object) 
102          """ 
103          self.__elem = value 
104   
105 -    def __getstate__(self): 
106          '''Enable pickling 
107           
108          @return: object's attribute dictionary 
109          @rtype: dict 
110          ''' 
111          _dict = {} 
112          for attrName in XacmlCoreBase.__slots__: 
113              # Ugly hack to allow for derived classes setting private member 
114              # variables 
115              if attrName.startswith('__'): 
116                  attrName = "_XacmlCoreBase" + attrName 
117                   
118              _dict[attrName] = getattr(self, attrName) 
119               
120          return _dict 
121               
122   
123 -class XacmlPolicyBase(XacmlCoreBase): 
124      """Base class for policy types 
125       
126      @cvar XACML_2_0_POLICY_NS: XACML 2.0 policy XML namespace 
127      @type XACML_2_0_POLICY_NS: string 
128      """ 
129      XACML_2_0_POLICY_NS = (XacmlCoreBase.XACML_2_0_NS_PREFIX + 
130                             ":policy:schema:os") 
131      __slots__ = () 
132       
133 -    def __init__(self): 
134          """Initialise parent class xmlns attribute based on this classes' 
135          policy namespace 
136          """ 
137          super(XacmlPolicyBase, self).__init__() 
138          self.xmlns = XacmlPolicyBase.XACML_2_0_POLICY_NS 
139               
140           
141 -class TargetChildBase(XacmlPolicyBase): 
142      """Abstract Base class for XACML Policy Subject, Resource, Action and  
143      Environment types: e.g. ndg.xacml.core.subject.Subject 
144       
145      @cvar MATCH_TYPE: Set the type for match attributes in the derived class 
146      implementation e.g. ResourceMatch, SubjectMatch etc. 
147      @type MATCH_TYPE: NoneType - derived class must implement 
148       
149      @ivar __matches: list of matches for this target 
150      @type __matches: ndg.xacml.core.utils.TypedList 
151      """ 
152      MATCH_TYPE = None 
153       
154      __slots__ = ('__matches', ) 
155       
156 -    def __init__(self): 
157          super(TargetChildBase, self).__init__() 
158           
159          # Derived types can specify the type for matches via the MATCH_TYPE 
160          # class variable 
161          if self.__class__.MATCH_TYPE is None: 
162              raise NotImplementedError('Match type attribute must be specified ' 
163                                        'in a derived class') 
164          self.__matches = TypedList(self.__class__.MATCH_TYPE) 
165           
166      @property 
167 -    def matches(self): 
168          """Get matches list for this target 
169          """ 
170          return self.__matches 
171       
172       
173  XACML_1_0_PREFIX = "urn:oasis:names:tc:xacml:1.0:" 
174   
175 -class Identifiers(object): 
176      """XACML Identifiers""" 
177 -    class Subject(object): 
178          """XAMCL Subject Identifiers""" 
179          AUTHN_LOCALITY_DNS_NAME = XACML_1_0_PREFIX + \ 
180              "subject:authn-locality:dns-name" 
181          AUTHN_LOCALITY_IP_ADDRESS = XACML_1_0_PREFIX + \ 
182              "subject:authn-locality:ip-address" 
183          AUTHN_METHOD = XACML_1_0_PREFIX + "subject:authentication-method" 
184          AUTHN_TIME = XACML_1_0_PREFIX + "subject:authentication-time" 
185          KEY_INFO = XACML_1_0_PREFIX + "subject:key-info" 
186          REQUEST_TIME = XACML_1_0_PREFIX + "subject:request-time" 
187          SESSION_START_TIME = XACML_1_0_PREFIX + "subject:session-start-time" 
188          SUBJECT_ID = XACML_1_0_PREFIX + "subject:subject-id" 
189          SUBJECT_ID_QUALIFIER = XACML_1_0_PREFIX + "subject:subject-id-qualifier" 
190           
191 -    class SubjectCategory(object): 
192          """XACML Subject Category Identifiers""" 
193          ACCESS_SUBJECT = XACML_1_0_PREFIX + "subject-category:access-subject" 
194          CODEBASE = XACML_1_0_PREFIX + "subject-category:codebase" 
195          INTERMEDIARY_SUBJECT = XACML_1_0_PREFIX + \ 
196              "subject-category:intermediary-subject" 
197          RECIPIENT_SUBJECT = XACML_1_0_PREFIX + \ 
198              "subject-category:recipient-subject" 
199          REQUESTING_MACHINE = XACML_1_0_PREFIX + \ 
200              "subject-category:requesting-machine" 
201           
202 -    class Resource(object): 
203          """XACML Resource Identifiers""" 
204          RESOURCE_LOCATION = XACML_1_0_PREFIX + "resource:resource-location" 
205          RESOURCE_ID = XACML_1_0_PREFIX + "resource:resource-id" 
206          SIMPLE_FILE_NAME = XACML_1_0_PREFIX + "resource:simple-file-name" 
207           
208 -    class Action(object): 
209          """XACML Action Identifiers""" 
210          ACTION_ID = XACML_1_0_PREFIX + "action:action-id" 
211          IMPLIED_ACTION = XACML_1_0_PREFIX + "action:implied-action" 
212        
213 -    class Environment(object): 
214          """XACML Environment Identifiers""" 
215          CURRENT_TIME = XACML_1_0_PREFIX + "environment:current-time" 
216          CURRENT_DATE = XACML_1_0_PREFIX + "environment:current-date" 
217          CURRENT_DATETIME = XACML_1_0_PREFIX + "environment:current-dateTime" 
218