freeipa/ipalib/plugins/hbactest.py
John Dennis 885bb07bb1 Fix name error in hbactest
Ticket #2512

In hbactest.py there is a name error wrapped inside a try/except block
that ignores all errors so the code block exits prematurely leaving a
critical variable uninitialized.

The name error is the result of a cut-n-paste error that references a
variable that had never been initialized in the scope of the code
block. Python generates an exception when this variable is referenced
but because it's wrapped in a try/except block that catches all errors
and ignores all errors there is no evidence that something went wrong.

The fix is to use the correct variables.

At some point we may want to revist if ignoring all errors and
proceding as if nothing happened is actually correct. Alexander tells
me this mimics what SSSD does in the hbac rule processing, thus the
ignoring of errors is intentional. But in a plugin whose purpose is to
test and exercise hbac rules I'm not sure ignoring all errors is
really the right behavior.
2012-04-19 15:22:49 +02:00

416 lines
16 KiB
Python

# 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)