mirror of https://github.com/MISP/misp-modules
				
				
				
			
		
			
				
	
	
		
			257 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			257 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			Python
		
	
	
| # encoding: utf-8
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| import json
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| import base64
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| import codecs
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| from dateutil.parser import isoparse
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| from . import check_input_attribute, standard_error_message
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| from pymisp import MISPAttribute, MISPEvent, MISPObject
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| try:
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|     import censys.base
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|     import censys.ipv4
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|     import censys.websites
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|     import censys.certificates
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| except ImportError:
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|     print("Censys module not installed. Try 'pip install censys'")
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| 
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| misperrors = {'error': 'Error'}
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| moduleconfig = ['api_id', 'api_secret']
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| mispattributes = {'input': ['ip-src', 'ip-dst', 'domain', 'hostname', 'hostname|port', 'domain|ip', 'ip-dst|port', 'ip-src|port',
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|                   'x509-fingerprint-md5', 'x509-fingerprint-sha1', 'x509-fingerprint-sha256'], 'format': 'misp_standard'}
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| moduleinfo = {'version': '0.1', 'author': 'Loïc Fortemps',
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|               'description': 'Censys.io expansion module', 'module-type': ['expansion', 'hover']}
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| 
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| 
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| def handler(q=False):
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|     if q is False:
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|         return False
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|     request = json.loads(q)
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| 
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|     if request.get('config'):
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|         if (request['config'].get('api_id') is None) or (request['config'].get('api_secret') is None):
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|             misperrors['error'] = "Censys API credentials are missing"
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|             return misperrors
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|     else:
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|         misperrors['error'] = "Please provide config options"
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|         return misperrors
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| 
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|     api_id = request['config']['api_id']
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|     api_secret = request['config']['api_secret']
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| 
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|     if not request.get('attribute') or not check_input_attribute(request['attribute']):
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|         return {'error': f'{standard_error_message}, which should contain at least a type, a value and an uuid.'}
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|     attribute = request['attribute']
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|     if not any(input_type == attribute['type'] for input_type in mispattributes['input']):
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|         return {'error': 'Unsupported attribute type.'}
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| 
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|     attribute = MISPAttribute()
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|     attribute.from_dict(**request['attribute'])
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|     # Lists to accomodate multi-types attribute
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|     conn = list()
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|     types = list()
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|     values = list()
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|     results = list()
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| 
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|     if "|" in attribute.type:
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|         t_1, t_2 = attribute.type.split('|')
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|         v_1, v_2 = attribute.value.split('|')
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|         # We cannot use the port information
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|         if t_2 == "port":
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|             types.append(t_1)
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|             values.append(v_1)
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|         else:
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|             types = [t_1, t_2]
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|             values = [v_1, v_2]
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|     else:
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|         types.append(attribute.type)
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|         values.append(attribute.value)
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| 
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|     for t in types:
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|         # ip, ip-src or ip-dst
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|         if t[:2] == "ip":
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|             conn.append(censys.ipv4.CensysIPv4(api_id=api_id, api_secret=api_secret))
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|         elif t == 'domain' or t == "hostname":
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|             conn.append(censys.websites.CensysWebsites(api_id=api_id, api_secret=api_secret))
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|         elif 'x509-fingerprint' in t:
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|             conn.append(censys.certificates.CensysCertificates(api_id=api_id, api_secret=api_secret))
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| 
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|     found = True
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|     for c in conn:
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|         val = values.pop(0)
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|         try:
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|             r = c.view(val)
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|             results.append(parse_response(r, attribute))
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|             found = True
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|         except censys.base.CensysNotFoundException:
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|             found = False
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|         except Exception:
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|             misperrors['error'] = "Connection issue"
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|             return misperrors
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| 
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|     if not found:
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|         misperrors['error'] = "Nothing could be found on Censys"
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|         return misperrors
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| 
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|     return {'results': remove_duplicates(results)}
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| 
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| 
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| def parse_response(censys_output, attribute):
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|     misp_event = MISPEvent()
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|     misp_event.add_attribute(**attribute)
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|     # Generic fields (for IP/Websites)
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|     if "autonomous_system" in censys_output:
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|         cen_as = censys_output['autonomous_system']
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|         asn_object = MISPObject('asn')
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|         asn_object.add_attribute('asn', value=cen_as["asn"])
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|         asn_object.add_attribute('description', value=cen_as['name'])
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|         asn_object.add_attribute('subnet-announced', value=cen_as['routed_prefix'])
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|         asn_object.add_attribute('country', value=cen_as['country_code'])
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|         asn_object.add_reference(attribute.uuid, 'associated-to')
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|         misp_event.add_object(**asn_object)
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| 
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|     if "ip" in censys_output and "ports" in censys_output:
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|         ip_object = MISPObject('ip-port')
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|         ip_object.add_attribute('ip', value=censys_output['ip'])
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|         for p in censys_output['ports']:
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|             ip_object.add_attribute('dst-port', value=p)
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|         ip_object.add_reference(attribute.uuid, 'associated-to')
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|         misp_event.add_object(**ip_object)
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| 
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|     # We explore all ports to find https or ssh services
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|     for k in censys_output.keys():
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|         if not isinstance(censys_output[k], dict):
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|             continue
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|         if 'https' in censys_output[k]:
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|             try:
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|                 cert = censys_output[k]['https']['tls']['certificate']
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|                 cert_obj = get_certificate_object(cert, attribute)
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|                 misp_event.add_object(**cert_obj)
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|             except KeyError:
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|                 print("Error !")
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|         if 'ssh' in censys_output[k]:
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|             try:
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|                 cert = censys_output[k]['ssh']['v2']['server_host_key']
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|                 # TODO enable once the type is merged
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|                 # misp_event.add_attribute(type='hasshserver-sha256', value=cert['fingerprint_sha256'])
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|             except KeyError:
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|                 pass
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| 
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|     # Info from certificate query
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|     if "parsed" in censys_output:
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|         cert_obj = get_certificate_object(censys_output, attribute)
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|         misp_event.add_object(**cert_obj)
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| 
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|     # Location can be present for IP/Websites results
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|     if "location" in censys_output:
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|         loc_obj = MISPObject('geolocation')
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|         loc = censys_output['location']
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|         loc_obj.add_attribute('latitude', value=loc['latitude'])
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|         loc_obj.add_attribute('longitude', value=loc['longitude'])
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|         if 'city' in loc:
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|             loc_obj.add_attribute('city', value=loc['city'])
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|         loc_obj.add_attribute('country', value=loc['country'])
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|         if 'postal_code' in loc:
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|             loc_obj.add_attribute('zipcode', value=loc['postal_code'])
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|         if 'province' in loc:
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|             loc_obj.add_attribute('region', value=loc['province'])
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|         loc_obj.add_reference(attribute.uuid, 'associated-to')
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|         misp_event.add_object(**loc_obj)
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| 
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|     event = json.loads(misp_event.to_json())
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|     return {'Object': event['Object'], 'Attribute': event['Attribute']}
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| 
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| 
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| # In case of multiple enrichment (ip and domain), we need to filter out similar objects
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| # TODO: make it more granular
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| def remove_duplicates(results):
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|     # Only one enrichment was performed so no duplicate
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|     if len(results) == 1:
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|         return results[0]
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|     elif len(results) == 2:
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|         final_result = results[0]
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|         obj_l2 = results[1]['Object']
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|         for o2 in obj_l2:
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|             if o2['name'] == "asn":
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|                 key = "asn"
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|             elif o2['name'] == "ip-port":
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|                 key = "ip"
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|             elif o2['name'] == "x509":
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|                 key = "x509-fingerprint-sha256"
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|             elif o2['name'] == "geolocation":
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|                 key = "latitude"
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|             if not check_if_present(o2, key, final_result['Object']):
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|                 final_result['Object'].append(o2)
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| 
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|         return final_result
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|     else:
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|         return []
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| 
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| 
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| def check_if_present(object, attribute_name, list_objects):
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|     """
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|     Assert if a given object is present in the list.
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| 
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|     This function check if object (json format) is present in list_objects
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|     using attribute_name for the matching
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|     """
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|     for o in list_objects:
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|         # We first look for a match on the name
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|         if o['name'] == object['name']:
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|             for attr in object['Attribute']:
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|                 # Within the attributes, we look for the one to compare
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|                 if attr['type'] == attribute_name:
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|                     # Then we check the attributes of the other object and look for a match
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|                     for attr2 in o['Attribute']:
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|                         if attr2['type'] == attribute_name and attr2['value'] == attr['value']:
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|                             return True
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| 
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|     return False
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| 
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| 
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| def get_certificate_object(cert, attribute):
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|     parsed = cert['parsed']
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|     cert_object = MISPObject('x509')
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|     cert_object.add_attribute('x509-fingerprint-sha256', value=parsed['fingerprint_sha256'])
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|     cert_object.add_attribute('x509-fingerprint-sha1', value=parsed['fingerprint_sha1'])
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|     cert_object.add_attribute('x509-fingerprint-md5', value=parsed['fingerprint_md5'])
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|     cert_object.add_attribute('serial-number', value=parsed['serial_number'])
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|     cert_object.add_attribute('version', value=parsed['version'])
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|     cert_object.add_attribute('subject', value=parsed['subject_dn'])
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|     cert_object.add_attribute('issuer', value=parsed['issuer_dn'])
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|     cert_object.add_attribute('validity-not-before', value=isoparse(parsed['validity']['start']))
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|     cert_object.add_attribute('validity-not-after', value=isoparse(parsed['validity']['end']))
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|     cert_object.add_attribute('self_signed', value=parsed['signature']['self_signed'])
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|     cert_object.add_attribute('signature_algorithm', value=parsed['signature']['signature_algorithm']['name'])
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| 
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|     cert_object.add_attribute('pubkey-info-algorithm', value=parsed['subject_key_info']['key_algorithm']['name'])
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| 
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|     if 'rsa_public_key' in parsed['subject_key_info']:
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|         pub_key = parsed['subject_key_info']['rsa_public_key']
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|         cert_object.add_attribute('pubkey-info-size', value=pub_key['length'])
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|         cert_object.add_attribute('pubkey-info-exponent', value=pub_key['exponent'])
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|         hex_mod = codecs.encode(base64.b64decode(pub_key['modulus']), 'hex').decode()
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|         cert_object.add_attribute('pubkey-info-modulus', value=hex_mod)
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| 
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|     if "extensions" in parsed and "subject_alt_name" in parsed["extensions"]:
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|         san = parsed["extensions"]["subject_alt_name"]
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|         if "dns_names" in san:
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|             for dns in san['dns_names']:
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|                 cert_object.add_attribute('dns_names', value=dns)
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|         if "ip_addresses" in san:
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|             for ip in san['ip_addresses']:
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|                 cert_object.add_attribute('ip', value=ip)
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| 
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|     if "raw" in cert:
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|         cert_object.add_attribute('raw-base64', value=cert['raw'])
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| 
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|     cert_object.add_reference(attribute.uuid, 'associated-to')
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|     return cert_object
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| 
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| 
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| def introspection():
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|     return mispattributes
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| 
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| 
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| def version():
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|     moduleinfo['config'] = moduleconfig
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|     return moduleinfo
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