shodan.py

# -*- coding: utf-8 -*-

import json
try:
    import shodan
except ImportError:
    print("shodan module not installed.")
from . import check_input_attribute, standard_error_message
from datetime import datetime
from pymisp import MISPAttribute, MISPEvent, MISPObject

misperrors = {'error': 'Error'}
mispattributes = {'input': ['ip-src', 'ip-dst'],
                  'format': 'misp_standard'}
moduleinfo = {'version': '0.2', 'author': 'Raphaël Vinot',
              'description': 'Query on Shodan',
              'module-type': ['expansion']}

moduleconfig = ['apikey']


class ShodanParser():
    def __init__(self, attribute):
        self.misp_event = MISPEvent()
        self.attribute = MISPAttribute()
        self.attribute.from_dict(**attribute)
        self.misp_event.add_attribute(**self.attribute)
        self.ip_address_mapping = {
            'asn': {'type': 'AS', 'object_relation': 'asn'},
            'city': {'type': 'text', 'object_relation': 'city'},
            'country_code': {'type': 'text', 'object_relation': 'country-code'},
            'country_name': {'type': 'text', 'object_relation': 'country'},
            'isp': {'type': 'text', 'object_relation': 'ISP'},
            'latitude': {'type': 'float', 'object_relation': 'latitude'},
            'longitude': {'type': 'float', 'object_relation': 'longitude'},
            'org': {'type': 'text', 'object_relation': 'organization'},
            'postal_code': {'type': 'text', 'object_relation': 'zipcode'},
            'region_code': {'type': 'text', 'object_relation': 'region-code'}
        }
        self.ip_port_mapping = {
            'domains': {'type': 'domain', 'object_relation': 'domain'},
            'hostnames': {'type': 'hostname', 'object_relation': 'hostname'}
        }
        self.vulnerability_mapping = {
            'cvss': {'type': 'float', 'object_relation': 'cvss-score'},
            'summary': {'type': 'text', 'object_relation': 'summary'}
        }
        self.x509_mapping = {
            'bits': {'type': 'text', 'object_relation': 'pubkey-info-size'},
            'expires': {'type': 'datetime', 'object_relation': 'validity-not-after'},
            'issued': {'type': 'datetime', 'object_relation': 'validity-not-before'},
            'issuer': {'type': 'text', 'object_relation': 'issuer'},
            'serial': {'type': 'text', 'object_relation': 'serial-number'},
            'sig_alg': {'type': 'text', 'object_relation': 'signature_algorithm'},
            'subject': {'type': 'text', 'object_relation': 'subject'},
            'type': {'type': 'text', 'object_relation': 'pubkey-info-algorithm'},
            'version': {'type': 'text', 'object_relation': 'version'}
        }

    def query_shodan(self, apikey):
        # Query Shodan and get the results in a json blob
        api = shodan.Shodan(apikey)
        query_results = api.host(self.attribute.value)

        # Parse the information about the IP address used as input
        ip_address_attributes = []
        for feature, mapping in self.ip_address_mapping.items():
            if query_results.get(feature):
                attribute = {'value': query_results[feature]}
                attribute.update(mapping)
                ip_address_attributes.append(attribute)
        if ip_address_attributes:
            ip_address_object = MISPObject('ip-api-address')
            for attribute in ip_address_attributes:
                ip_address_object.add_attribute(**attribute)
            ip_address_object.add_reference(self.attribute.uuid, 'describes')
            self.misp_event.add_object(ip_address_object)

        # Parse the hostnames / domains and ports associated with the IP address
        if query_results.get('ports'):
            ip_port_object = MISPObject('ip-port')
            ip_port_object.add_attribute(**self._get_source_attribute())
            feature = self.attribute.type.split('-')[1]
            for port in query_results['ports']:
                attribute = {
                    'type': 'port',
                    'object_relation': f'{feature}-port',
                    'value': port
                }
                ip_port_object.add_attribute(**attribute)
            for feature, mapping in self.ip_port_mapping.items():
                for value in query_results.get(feature, []):
                    attribute = {'value': value}
                    attribute.update(mapping)
                    ip_port_object.add_attribute(**attribute)
            ip_port_object.add_reference(self.attribute.uuid, 'extends')
            self.misp_event.add_object(ip_port_object)
        else:
            if any(query_results.get(feature) for feature in ('domains', 'hostnames')):
                domain_ip_object = MISPObject('domain-ip')
                domain_ip_object.add_attribute(**self._get_source_attribute())
                for feature in ('domains', 'hostnames'):
                    for value in query_results[feature]:
                        attribute = {
                            'type': 'domain',
                            'object_relation': 'domain',
                            'value': value
                        }
                        domain_ip_object.add_attribute(**attribute)
                domain_ip_object.add_reference(self.attribute.uuid, 'extends')
                self.misp_event.add_object(domain_ip_object)

        # Parse data within the "data" field
        if query_results.get('vulns'):
            vulnerabilities = {}
            for data in query_results['data']:
                # Parse vulnerabilities
                if data.get('vulns'):
                    for cve, vulnerability in data['vulns'].items():
                        if cve not in vulnerabilities:
                            vulnerabilities[cve] = vulnerability
                # Also parse the certificates
                if data.get('ssl'):
                    self._parse_cert(data['ssl'])
            for cve, vulnerability in vulnerabilities.items():
                vulnerability_object = MISPObject('vulnerability')
                vulnerability_object.add_attribute(**{
                    'type': 'vulnerability',
                    'object_relation': 'id',
                    'value': cve
                })
                for feature, mapping in self.vulnerability_mapping.items():
                    if vulnerability.get(feature):
                        attribute = {'value': vulnerability[feature]}
                        attribute.update(mapping)
                        vulnerability_object.add_attribute(**attribute)
                if vulnerability.get('references'):
                    for reference in vulnerability['references']:
                        vulnerability_object.add_attribute(**{
                            'type': 'link',
                            'object_relation': 'references',
                            'value': reference
                        })
                vulnerability_object.add_reference(self.attribute.uuid, 'vulnerability-of')
                self.misp_event.add_object(vulnerability_object)
            for cve_id in query_results['vulns']:
                if cve_id not in vulnerabilities:
                    attribute = {
                        'type': 'vulnerability',
                        'value': cve_id
                    }
                    self.misp_event.add_attribute(**attribute)
        else:
            # We have no vulnerability data, we only check if we have
            # certificates within the "data" field
            for data in query_results['data']:
                if data.get('ssl'):
                    self._parse_cert(data['ssl']['cert'])

    def get_result(self):
        event = json.loads(self.misp_event.to_json())
        results = {key: event[key] for key in ('Attribute', 'Object') if (key in event and event[key])}
        return {'results': results}

    # When we want to add the IP address information in objects such as the
    # domain-ip or ip-port objects referencing the input IP address attribute
    def _get_source_attribute(self):
        return {
            'type': self.attribute.type,
            'object_relation': self.attribute.type,
            'value': self.attribute.value
        }

    def _parse_cert(self, certificate):
        x509_object = MISPObject('x509')
        for feature in ('serial', 'sig_alg', 'version'):
            if certificate.get(feature):
                attribute = {'value': certificate[feature]}
                attribute.update(self.x509_mapping[feature])
                x509_object.add_attribute(**attribute)
        # Parse issuer and subject value
        for feature in ('issuer', 'subject'):
            if certificate.get(feature):
                attribute_value = (f'{identifier}={value}' for identifier, value in certificate[feature].items())
                attribute = {'value': f'/{"/".join(attribute_value)}'}
                attribute.update(self.x509_mapping[feature])
                x509_object.add_attribute(**attribute)
        # Parse datetime attributes
        for feature in ('expires', 'issued'):
            if certificate.get(feature):
                attribute = {'value': datetime.strptime(certificate[feature], '%Y%m%d%H%M%SZ')}
                attribute.update(self.x509_mapping[feature])
                x509_object.add_attribute(**attribute)
        # Parse fingerprints
        if certificate.get('fingerprint'):
            for hash_type, hash_value in certificate['fingerprint'].items():
                x509_object.add_attribute(**{
                    'type': f'x509-fingerprint-{hash_type}',
                    'object_relation': f'x509-fingerprint-{hash_type}',
                    'value': hash_value
                })
        # Parse public key related info
        if certificate.get('pubkey'):
            for feature, value in certificate['pubkey'].items():
                attribute = {'value': value}
                attribute.update(self.x509_mapping[feature])
                x509_object.add_attribute(**attribute)
        x509_object.add_reference(self.attribute.uuid, 'identifies')
        self.misp_event.add_object(x509_object)


def handler(q=False):
    if q is False:
        return False
    request = json.loads(q)
    if not request.get('config', {}).get('apikey'):
        return {'error': 'Shodan authentication is missing'}
    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.'}
    attribute = request['attribute']
    if attribute['type'] not in mispattributes['input']:
        return {'error': 'Unsupported attribute type.'}
    shodan_parser = ShodanParser(attribute)
    shodan_parser.query_shodan(request['config']['apikey'])
    return shodan_parser.get_result()


def introspection():
    return mispattributes


def version():
    moduleinfo['config'] = moduleconfig
    return moduleinfo