misp-modules/misp_modules/modules/expansion/censys_enrich.py

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2020-04-03 12:15:03 +02:00
# encoding: utf-8
import json
import base64
import codecs
from dateutil.parser import isoparse
from . import check_input_attribute, standard_error_message
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from pymisp import MISPAttribute, MISPEvent, MISPObject
try:
import censys.base
import censys.ipv4
import censys.websites
import censys.certificates
except ImportError:
print("Censys module not installed. Try 'pip install censys'")
misperrors = {'error': 'Error'}
moduleconfig = ['api_id', 'api_secret']
mispattributes = {'input': ['ip-src', 'ip-dst', 'domain', 'hostname', 'hostname|port', 'domain|ip', 'ip-dst|port', 'ip-src|port',
'x509-fingerprint-md5', 'x509-fingerprint-sha1', 'x509-fingerprint-sha256'], 'format': 'misp_standard'}
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moduleinfo = {'version': '0.1', 'author': 'Loïc Fortemps',
'description': 'Censys.io expansion module', 'module-type': ['expansion', 'hover']}
def handler(q=False):
if q is False:
return False
request = json.loads(q)
if request.get('config'):
if (request['config'].get('api_id') is None) or (request['config'].get('api_secret') is None):
misperrors['error'] = "Censys API credentials are missing"
return misperrors
else:
misperrors['error'] = "Please provide config options"
return misperrors
api_id = request['config']['api_id']
api_secret = request['config']['api_secret']
if not request.get('attribute') or not check_input_attribute(request['attribute']):
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']
if not any(input_type == attribute['type'] for input_type in mispattributes['input']):
return {'error': 'Unsupported attribute type.'}
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attribute = MISPAttribute()
attribute.from_dict(**request['attribute'])
# Lists to accomodate multi-types attribute
conn = list()
types = list()
values = list()
results = list()
if "|" in attribute.type:
t_1, t_2 = attribute.type.split('|')
v_1, v_2 = attribute.value.split('|')
# We cannot use the port information
if t_2 == "port":
types.append(t_1)
values.append(v_1)
else:
types = [t_1, t_2]
values = [v_1, v_2]
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else:
types.append(attribute.type)
values.append(attribute.value)
for t in types:
# ip, ip-src or ip-dst
if t[:2] == "ip":
conn.append(censys.ipv4.CensysIPv4(api_id=api_id, api_secret=api_secret))
elif t == 'domain' or t == "hostname":
conn.append(censys.websites.CensysWebsites(api_id=api_id, api_secret=api_secret))
elif 'x509-fingerprint' in t:
conn.append(censys.certificates.CensysCertificates(api_id=api_id, api_secret=api_secret))
found = True
for c in conn:
val = values.pop(0)
try:
r = c.view(val)
results.append(parse_response(r, attribute))
found = True
except censys.base.CensysNotFoundException:
found = False
except Exception:
misperrors['error'] = "Connection issue"
return misperrors
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if not found:
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misperrors['error'] = "Nothing could be found on Censys"
return misperrors
return {'results': remove_duplicates(results)}
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def parse_response(censys_output, attribute):
misp_event = MISPEvent()
misp_event.add_attribute(**attribute)
# Generic fields (for IP/Websites)
if "autonomous_system" in censys_output:
cen_as = censys_output['autonomous_system']
asn_object = MISPObject('asn')
asn_object.add_attribute('asn', value=cen_as["asn"])
asn_object.add_attribute('description', value=cen_as['name'])
asn_object.add_attribute('subnet-announced', value=cen_as['routed_prefix'])
asn_object.add_attribute('country', value=cen_as['country_code'])
asn_object.add_reference(attribute.uuid, 'associated-to')
misp_event.add_object(**asn_object)
if "ip" in censys_output and "ports" in censys_output:
ip_object = MISPObject('ip-port')
ip_object.add_attribute('ip', value=censys_output['ip'])
for p in censys_output['ports']:
ip_object.add_attribute('dst-port', value=p)
ip_object.add_reference(attribute.uuid, 'associated-to')
misp_event.add_object(**ip_object)
# We explore all ports to find https or ssh services
for k in censys_output.keys():
if not isinstance(censys_output[k], dict):
continue
if 'https' in censys_output[k]:
try:
cert = censys_output[k]['https']['tls']['certificate']
cert_obj = get_certificate_object(cert, attribute)
misp_event.add_object(**cert_obj)
except KeyError:
print("Error !")
if 'ssh' in censys_output[k]:
try:
cert = censys_output[k]['ssh']['v2']['server_host_key']
# TODO enable once the type is merged
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# misp_event.add_attribute(type='hasshserver-sha256', value=cert['fingerprint_sha256'])
except KeyError:
pass
# Info from certificate query
if "parsed" in censys_output:
cert_obj = get_certificate_object(censys_output, attribute)
misp_event.add_object(**cert_obj)
# Location can be present for IP/Websites results
if "location" in censys_output:
loc_obj = MISPObject('geolocation')
loc = censys_output['location']
loc_obj.add_attribute('latitude', value=loc['latitude'])
loc_obj.add_attribute('longitude', value=loc['longitude'])
if 'city' in loc:
loc_obj.add_attribute('city', value=loc['city'])
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loc_obj.add_attribute('country', value=loc['country'])
if 'postal_code' in loc:
loc_obj.add_attribute('zipcode', value=loc['postal_code'])
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if 'province' in loc:
loc_obj.add_attribute('region', value=loc['province'])
loc_obj.add_reference(attribute.uuid, 'associated-to')
misp_event.add_object(**loc_obj)
event = json.loads(misp_event.to_json())
return {'Object': event['Object'], 'Attribute': event['Attribute']}
# In case of multiple enrichment (ip and domain), we need to filter out similar objects
# TODO: make it more granular
def remove_duplicates(results):
# Only one enrichment was performed so no duplicate
if len(results) == 1:
return results[0]
elif len(results) == 2:
final_result = results[0]
obj_l2 = results[1]['Object']
for o2 in obj_l2:
if o2['name'] == "asn":
key = "asn"
elif o2['name'] == "ip-port":
key = "ip"
elif o2['name'] == "x509":
key = "x509-fingerprint-sha256"
elif o2['name'] == "geolocation":
key = "latitude"
if not check_if_present(o2, key, final_result['Object']):
final_result['Object'].append(o2)
return final_result
else:
return []
def check_if_present(object, attribute_name, list_objects):
"""
Assert if a given object is present in the list.
This function check if object (json format) is present in list_objects
using attribute_name for the matching
"""
for o in list_objects:
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# We first look for a match on the name
if o['name'] == object['name']:
for attr in object['Attribute']:
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# Within the attributes, we look for the one to compare
if attr['type'] == attribute_name:
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# Then we check the attributes of the other object and look for a match
for attr2 in o['Attribute']:
if attr2['type'] == attribute_name and attr2['value'] == attr['value']:
return True
return False
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def get_certificate_object(cert, attribute):
parsed = cert['parsed']
cert_object = MISPObject('x509')
cert_object.add_attribute('x509-fingerprint-sha256', value=parsed['fingerprint_sha256'])
cert_object.add_attribute('x509-fingerprint-sha1', value=parsed['fingerprint_sha1'])
cert_object.add_attribute('x509-fingerprint-md5', value=parsed['fingerprint_md5'])
cert_object.add_attribute('serial-number', value=parsed['serial_number'])
cert_object.add_attribute('version', value=parsed['version'])
cert_object.add_attribute('subject', value=parsed['subject_dn'])
cert_object.add_attribute('issuer', value=parsed['issuer_dn'])
cert_object.add_attribute('validity-not-before', value=isoparse(parsed['validity']['start']))
cert_object.add_attribute('validity-not-after', value=isoparse(parsed['validity']['end']))
cert_object.add_attribute('self_signed', value=parsed['signature']['self_signed'])
cert_object.add_attribute('signature_algorithm', value=parsed['signature']['signature_algorithm']['name'])
cert_object.add_attribute('pubkey-info-algorithm', value=parsed['subject_key_info']['key_algorithm']['name'])
if 'rsa_public_key' in parsed['subject_key_info']:
pub_key = parsed['subject_key_info']['rsa_public_key']
cert_object.add_attribute('pubkey-info-size', value=pub_key['length'])
cert_object.add_attribute('pubkey-info-exponent', value=pub_key['exponent'])
hex_mod = codecs.encode(base64.b64decode(pub_key['modulus']), 'hex').decode()
cert_object.add_attribute('pubkey-info-modulus', value=hex_mod)
if "extensions" in parsed and "subject_alt_name" in parsed["extensions"]:
san = parsed["extensions"]["subject_alt_name"]
if "dns_names" in san:
for dns in san['dns_names']:
cert_object.add_attribute('dns_names', value=dns)
if "ip_addresses" in san:
for ip in san['ip_addresses']:
cert_object.add_attribute('ip', value=ip)
if "raw" in cert:
cert_object.add_attribute('raw-base64', value=cert['raw'])
cert_object.add_reference(attribute.uuid, 'associated-to')
return cert_object
def introspection():
return mispattributes
def version():
moduleinfo['config'] = moduleconfig
return moduleinfo