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# Authors: 

#   Alexander Bokovoy <abokovoy@redhat.com> 

# 

# 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 <http://www.gnu.org/licenses/>. 

 

from ipalib import api, errors, output 

from ipalib import Command, Str, Flag, Int 

from types import NoneType 

from ipalib.cli import to_cli 

from ipalib import _, ngettext 

import pyhbac 

 

__doc__ = _(""" 

Simulate use of Host-based access controls 

 

HBAC rules control who can access what services on what hosts and from where. 

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] 

              [--srchost= ] [--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. 

 

If --srchost is specified, it will be ignored. It is left because of compatibility reasons only. 

 

EXAMPLES: 

 

    1. Use all enabled HBAC rules in IPA database to simulate: 

    $ ipa  hbactest --user=a1a --host=bar --service=sshd 

    -------------------- 

    Access granted: True 

    -------------------- 

      notmatched: my-second-rule 

      notmatched: my-third-rule 

      notmatched: myrule 

      matched: 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=my-second-rule,myrule 

    --------------------- 

    Access granted: False 

    --------------------- 

      notmatched: my-second-rule 

      notmatched: myrule 

 

    4. Use all enabled HBAC rules in IPA database + explicitly specified rules: 

    $ ipa hbactest --user=a1a --host=bar --service=sshd \ 

          --rules=my-second-rule,myrule --enabled 

    -------------------- 

    Access granted: True 

    -------------------- 

      notmatched: my-second-rule 

      notmatched: my-third-rule 

      notmatched: myrule 

      matched: allow_all 

 

    5. Test all disabled HBAC rules in IPA database: 

    $ ipa hbactest --user=a1a --host=bar --service=sshd --disabled 

    --------------------- 

    Access granted: False 

    --------------------- 

      notmatched: new-rule 

 

    6. Test all disabled HBAC rules in IPA database + explicitly specified rules: 

    $ ipa hbactest --user=a1a --host=bar --service=sshd \ 

          --rules=my-second-rule,myrule --disabled 

    --------------------- 

    Access granted: False 

    --------------------- 

      notmatched: my-second-rule 

      notmatched: my-third-rule 

      notmatched: 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 

    -------------------- 

      notmatched: my-second-rule 

      notmatched: my-third-rule 

      notmatched: myrule 

      notmatched: new-rule 

      matched: allow_all 

 

""") 

 

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 

 

 

class hbactest(Command): 

    __doc__ = _('Simulate use of Host-based access controls') 

 

    has_output = ( 

        output.summary, 

        output.Output('warning', (list, tuple, NoneType),   _('Warning')), 

        output.Output('matched', (list, tuple, NoneType),   _('Matched rules')), 

        output.Output('notmatched', (list, tuple, NoneType), _('Not matched rules')), 

        output.Output('error', (list, tuple, NoneType), _('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?', 

            cli_name='srchost', 

            label=_('Source host'), 

        ), 

        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'), 

             csv=True, 

        ), 

        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, source host, 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)['result'] 

        else: 

            for rule in testrules: 

                try: 

                    hbacset.append(self.api.Command.hbacrule_show(rule)['result']) 

                except: 

                    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': 

            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: 

                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: 

                pass 

 

        if options.get('sourcehost'): 

            warning_flag = True 

            if options['sourcehost'] != u'all': 

                try: 

                    request.srchost.name = self.canonicalize(options['sourcehost']) 

                    srchost_result = self.api.Command.host_show(request.srchost.name)['result'] 

                    groups = srchost_result['memberof_hostgroup'] 

                    if 'memberofindirect_hostgroup' in srchost_result: 

                        groups += srchost_result['memberofindirect_hostgroup'] 

                    request.srchost.groups = sorted(set(groups)) 

                except: 

                     pass 

        else: 

            warning_flag = False 

 

        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: 

                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) 

                    if warning_flag: 

                        warning_rules.append(_(u'Sourcehost value of rule "%s" is ignored') % (ipa_rule.name)) 

                except pyhbac.HbacError as (code, rule_name): 

                    if code == pyhbac.HBAC_EVAL_ERROR: 

                        error_rules.append(rule_name) 

                        self.log.info('Native IPA HBAC rule "%s" parsing error: %s' % \ 

                                      (rule_name, pyhbac.hbac_result_string(code))) 

                except (TypeError, IOError) as (info): 

                    self.log.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 

 

    def output_for_cli(self, textui, output, *args, **options): 

        """ 

        Command.output_for_cli() uses --all option to decide whether to print detailed output. 

        We use --detail to allow that, thus we need to redefine output_for_cli(). 

        """ 

        # Note that we don't actually use --detail below to see if details need 

        # to be printed as our execute() method will return None for corresponding 

        # entries and None entries will be skipped. 

        for o in self.output: 

            outp = self.output[o] 

            if 'no_display' in outp.flags: 

                continue 

            result = output[o] 

            if isinstance(result, (list, tuple)): 

                textui.print_attribute(unicode(outp.doc), result, '%s: %s', 1, True) 

            elif isinstance(result, (unicode, bool)): 

                if o == 'summary': 

                    textui.print_summary(result) 

                else: 

                    textui.print_indented(result) 

 

        # Propagate integer value for result. It will give proper command line result for scripts 

        return int(not output['value']) 

 

api.register(hbactest)