# Authors: # Alexander Bokovoy # # Copyright (C) 2011 Red Hat # see file 'COPYING' for use and warranty information # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program. If not, see . import logging from ipalib import api, errors, output, util from ipalib import Command, Str, Flag, Int from ipalib import _ from ipapython.dn import DN from ipalib.plugable import Registry if api.env.in_server: try: import ipaserver.dcerpc _dcerpc_bindings_installed = True except ImportError: _dcerpc_bindings_installed = False import six try: import pyhbac except ImportError: raise errors.SkipPluginModule(reason=_('pyhbac is not installed.')) if six.PY3: unicode = str __doc__ = _(r""" Simulate use of Host-based access controls HBAC rules control who can access what services on what hosts. You can use HBAC to control which users or groups can access a service, or group of services, on a target host. Since applying HBAC rules implies use of a production environment, this plugin aims to provide simulation of HBAC rules evaluation without having access to the production environment. Test user coming to a service on a named host against existing enabled rules. ipa hbactest --user= --host= --service= [--rules=rules-list] [--nodetail] [--enabled] [--disabled] [--sizelimit= ] --user, --host, and --service are mandatory, others are optional. If --rules is specified simulate enabling of the specified rules and test the login of the user using only these rules. If --enabled is specified, all enabled HBAC rules will be added to simulation If --disabled is specified, all disabled HBAC rules will be added to simulation If --nodetail is specified, do not return information about rules matched/not matched. If both --rules and --enabled are specified, apply simulation to --rules _and_ all IPA enabled rules. If no --rules specified, simulation is run against all IPA enabled rules. By default there is a IPA-wide limit to number of entries fetched, you can change it with --sizelimit option. EXAMPLES: 1. Use all enabled HBAC rules in IPA database to simulate: $ ipa hbactest --user=a1a --host=bar --service=sshd -------------------- Access granted: True -------------------- Not matched rules: my-second-rule Not matched rules: my-third-rule Not matched rules: myrule Matched rules: allow_all 2. Disable detailed summary of how rules were applied: $ ipa hbactest --user=a1a --host=bar --service=sshd --nodetail -------------------- Access granted: True -------------------- 3. Test explicitly specified HBAC rules: $ ipa hbactest --user=a1a --host=bar --service=sshd \\ --rules=myrule --rules=my-second-rule --------------------- Access granted: False --------------------- Not matched rules: my-second-rule Not matched rules: myrule 4. Use all enabled HBAC rules in IPA database + explicitly specified rules: $ ipa hbactest --user=a1a --host=bar --service=sshd \\ --rules=myrule --rules=my-second-rule --enabled -------------------- Access granted: True -------------------- Not matched rules: my-second-rule Not matched rules: my-third-rule Not matched rules: myrule Matched rules: allow_all 5. Test all disabled HBAC rules in IPA database: $ ipa hbactest --user=a1a --host=bar --service=sshd --disabled --------------------- Access granted: False --------------------- Not matched rules: new-rule 6. Test all disabled HBAC rules in IPA database + explicitly specified rules: $ ipa hbactest --user=a1a --host=bar --service=sshd \\ --rules=myrule --rules=my-second-rule --disabled --------------------- Access granted: False --------------------- Not matched rules: my-second-rule Not matched rules: my-third-rule Not matched rules: myrule 7. Test all (enabled and disabled) HBAC rules in IPA database: $ ipa hbactest --user=a1a --host=bar --service=sshd \\ --enabled --disabled -------------------- Access granted: True -------------------- Not matched rules: my-second-rule Not matched rules: my-third-rule Not matched rules: myrule Not matched rules: new-rule Matched rules: allow_all HBACTEST AND TRUSTED DOMAINS When an external trusted domain is configured in IPA, HBAC rules are also applied on users accessing IPA resources from the trusted domain. Trusted domain users and groups (and their SIDs) can be then assigned to external groups which can be members of POSIX groups in IPA which can be used in HBAC rules and thus allowing access to resources protected by the HBAC system. hbactest plugin is capable of testing access for both local IPA users and users from the trusted domains, either by a fully qualified user name or by user SID. Such user names need to have a trusted domain specified as a short name (DOMAIN\Administrator) or with a user principal name (UPN), Administrator@ad.test. Please note that hbactest executed with a trusted domain user as --user parameter can be only run by members of "trust admins" group. EXAMPLES: 1. Test if a user from a trusted domain specified by its shortname matches any rule: $ ipa hbactest --user 'DOMAIN\Administrator' --host `hostname` --service sshd -------------------- Access granted: True -------------------- Matched rules: allow_all Matched rules: can_login 2. Test if a user from a trusted domain specified by its domain name matches any rule: $ ipa hbactest --user 'Administrator@domain.com' --host `hostname` --service sshd -------------------- Access granted: True -------------------- Matched rules: allow_all Matched rules: can_login 3. Test if a user from a trusted domain specified by its SID matches any rule: $ ipa hbactest --user S-1-5-21-3035198329-144811719-1378114514-500 \\ --host `hostname` --service sshd -------------------- Access granted: True -------------------- Matched rules: allow_all Matched rules: can_login 4. Test if other user from a trusted domain specified by its SID matches any rule: $ ipa hbactest --user S-1-5-21-3035198329-144811719-1378114514-1203 \\ --host `hostname` --service sshd -------------------- Access granted: True -------------------- Matched rules: allow_all Not matched rules: can_login 5. Test if other user from a trusted domain specified by its shortname matches any rule: $ ipa hbactest --user 'DOMAIN\Otheruser' --host `hostname` --service sshd -------------------- Access granted: True -------------------- Matched rules: allow_all Not matched rules: can_login """) logger = logging.getLogger(__name__) register = Registry() def _convert_to_ipa_rule(rule): # convert a dict with a rule to an pyhbac rule ipa_rule = pyhbac.HbacRule(rule['cn'][0]) ipa_rule.enabled = rule['ipaenabledflag'][0] # Following code attempts to process rule systematically structure = \ (('user', 'memberuser', 'user', 'group', ipa_rule.users), ('host', 'memberhost', 'host', 'hostgroup', ipa_rule.targethosts), ('sourcehost', 'sourcehost', 'host', 'hostgroup', ipa_rule.srchosts), ('service', 'memberservice', 'hbacsvc', 'hbacsvcgroup', ipa_rule.services), ) for element in structure: category = '%scategory' % (element[0]) if (category in rule and rule[category][0] == u'all') or (element[0] == 'sourcehost'): # rule applies to all elements # sourcehost is always set to 'all' element[4].category = set([pyhbac.HBAC_CATEGORY_ALL]) else: # rule is about specific entities # Check if there are explicitly listed entities attr_name = '%s_%s' % (element[1], element[2]) if attr_name in rule: element[4].names = rule[attr_name] # Now add groups of entities if they are there attr_name = '%s_%s' % (element[1], element[3]) if attr_name in rule: element[4].groups = rule[attr_name] if 'externalhost' in rule: ipa_rule.srchosts.names.extend(rule['externalhost']) #pylint: disable=E1101 return ipa_rule @register() class hbactest(Command): __doc__ = _('Simulate use of Host-based access controls') has_output = ( output.summary, output.Output('warning', (list, tuple, type(None)), _('Warning')), output.Output('matched', (list, tuple, type(None)), _('Matched rules')), output.Output('notmatched', (list, tuple, type(None)), _('Not matched rules')), output.Output('error', (list, tuple, type(None)), _('Non-existent or invalid rules')), output.Output('value', bool, _('Result of simulation'), ['no_display']), ) takes_options = ( Str('user', cli_name='user', label=_('User name'), primary_key=True, ), Str('sourcehost?', deprecated=True, cli_name='srchost', label=_('Source host'), flags={'no_option'}, ), Str('targethost', cli_name='host', label=_('Target host'), ), Str('service', cli_name='service', label=_('Service'), ), Str('rules*', cli_name='rules', label=_('Rules to test. If not specified, --enabled is assumed'), ), Flag('nodetail?', cli_name='nodetail', label=_('Hide details which rules are matched, not matched, or invalid'), ), Flag('enabled?', cli_name='enabled', label=_('Include all enabled IPA rules into test [default]'), ), Flag('disabled?', cli_name='disabled', label=_('Include all disabled IPA rules into test'), ), Int('sizelimit?', label=_('Size Limit'), doc=_('Maximum number of rules to process when no --rules is specified'), flags=['no_display'], minvalue=0, autofill=False, ), ) def canonicalize(self, host): """ Canonicalize the host name -- add default IPA domain if that is missing """ if host.find('.') == -1: return u'%s.%s' % (host, self.env.domain) return host def execute(self, *args, **options): # First receive all needed information: # 1. HBAC rules (whether enabled or disabled) # 2. Required options are (user, target host, service) # 3. Options: rules to test (--rules, --enabled, --disabled), request for detail output rules = [] # Use all enabled IPA rules by default all_enabled = True all_disabled = False # We need a local copy of test rules in order find incorrect ones testrules = {} if 'rules' in options: testrules = list(options['rules']) # When explicit rules are provided, disable assumptions all_enabled = False all_disabled = False sizelimit = None if 'sizelimit' in options: sizelimit = int(options['sizelimit']) # Check if --disabled is specified, include all disabled IPA rules if options['disabled']: all_disabled = True all_enabled = False # Finally, if enabled is specified implicitly, override above decisions if options['enabled']: all_enabled = True hbacset = [] if len(testrules) == 0: hbacset = self.api.Command.hbacrule_find( sizelimit=sizelimit, no_members=False)['result'] else: for rule in testrules: try: hbacset.append(self.api.Command.hbacrule_show(rule)['result']) except Exception: pass # We have some rules, import them # --enabled will import all enabled rules (default) # --disabled will import all disabled rules # --rules will implicitly add the rules from a rule list for rule in hbacset: ipa_rule = _convert_to_ipa_rule(rule) if ipa_rule.name in testrules: ipa_rule.enabled = True rules.append(ipa_rule) testrules.remove(ipa_rule.name) elif all_enabled and ipa_rule.enabled: # Option --enabled forces to include all enabled IPA rules into test rules.append(ipa_rule) elif all_disabled and not ipa_rule.enabled: # Option --disabled forces to include all disabled IPA rules into test ipa_rule.enabled = True rules.append(ipa_rule) # Check if there are unresolved rules left if len(testrules) > 0: # Error, unresolved rules are left in --rules return {'summary' : unicode(_(u'Unresolved rules in --rules')), 'error': testrules, 'matched': None, 'notmatched': None, 'warning' : None, 'value' : False} # Rules are converted to pyhbac format, build request and then test it request = pyhbac.HbacRequest() if options['user'] != u'all': # check first if this is not a trusted domain user if _dcerpc_bindings_installed: is_valid_sid = ipaserver.dcerpc.is_sid_valid(options['user']) else: is_valid_sid = False components = util.normalize_name(options['user']) if is_valid_sid or 'domain' in components or 'flatname' in components: # this is a trusted domain user if not _dcerpc_bindings_installed: raise errors.NotFound(reason=_( 'Cannot perform external member validation without ' 'Samba 4 support installed. Make sure you have installed ' 'server-trust-ad sub-package of IPA on the server')) domain_validator = ipaserver.dcerpc.DomainValidator(self.api) if not domain_validator.is_configured(): raise errors.NotFound(reason=_( 'Cannot search in trusted domains without own domain configured. ' 'Make sure you have run ipa-adtrust-install on the IPA server first')) user_sid, group_sids = domain_validator.get_trusted_domain_user_and_groups(options['user']) request.user.name = user_sid # Now search for all external groups that have this user or # any of its groups in its external members. Found entires # memberOf links will be then used to gather all groups where # this group is assigned, including the nested ones filter_sids = "(&(objectclass=ipaexternalgroup)(|(ipaExternalMember=%s)))" \ % ")(ipaExternalMember=".join(group_sids + [user_sid]) ldap = self.api.Backend.ldap2 group_container = DN(api.env.container_group, api.env.basedn) try: entries, _truncated = ldap.find_entries( filter_sids, ['memberof'], group_container) except errors.NotFound: request.user.groups = [] else: groups = [] for entry in entries: memberof_dns = entry.get('memberof', []) for memberof_dn in memberof_dns: if memberof_dn.endswith(group_container): groups.append(memberof_dn[0][0].value) request.user.groups = sorted(set(groups)) else: # try searching for a local user try: request.user.name = options['user'] search_result = self.api.Command.user_show(request.user.name)['result'] groups = search_result['memberof_group'] if 'memberofindirect_group' in search_result: groups += search_result['memberofindirect_group'] request.user.groups = sorted(set(groups)) except Exception: pass if options['service'] != u'all': try: request.service.name = options['service'] service_result = self.api.Command.hbacsvc_show(request.service.name)['result'] if 'memberof_hbacsvcgroup' in service_result: request.service.groups = service_result['memberof_hbacsvcgroup'] except Exception: pass if options['targethost'] != u'all': try: request.targethost.name = self.canonicalize(options['targethost']) tgthost_result = self.api.Command.host_show(request.targethost.name)['result'] groups = tgthost_result['memberof_hostgroup'] if 'memberofindirect_hostgroup' in tgthost_result: groups += tgthost_result['memberofindirect_hostgroup'] request.targethost.groups = sorted(set(groups)) except Exception: pass matched_rules = [] notmatched_rules = [] error_rules = [] warning_rules = [] result = {'warning':None, 'matched':None, 'notmatched':None, 'error':None} if not options['nodetail']: # Validate runs rules one-by-one and reports failed ones for ipa_rule in rules: try: res = request.evaluate([ipa_rule]) if res == pyhbac.HBAC_EVAL_ALLOW: matched_rules.append(ipa_rule.name) if res == pyhbac.HBAC_EVAL_DENY: notmatched_rules.append(ipa_rule.name) except pyhbac.HbacError as e: code, rule_name = e.args if code == pyhbac.HBAC_EVAL_ERROR: error_rules.append(rule_name) logger.info('Native IPA HBAC rule "%s" parsing error: ' '%s', rule_name, pyhbac.hbac_result_string(code)) except (TypeError, IOError) as info: logger.error('Native IPA HBAC module error: %s', info) access_granted = len(matched_rules) > 0 else: res = request.evaluate(rules) access_granted = (res == pyhbac.HBAC_EVAL_ALLOW) result['summary'] = _('Access granted: %s') % (access_granted) if len(matched_rules) > 0: result['matched'] = matched_rules if len(notmatched_rules) > 0: result['notmatched'] = notmatched_rules if len(error_rules) > 0: result['error'] = error_rules if len(warning_rules) > 0: result['warning'] = warning_rules result['value'] = access_granted return result