4 This tool is for checking the security hardening options of the Linux kernel.
6 Author: Alexander Popov <alex.popov@linux.com>
8 This module is the engine of checks.
11 # pylint: disable=missing-class-docstring,missing-function-docstring
12 # pylint: disable=line-too-long,invalid-name,too-many-branches
14 from typing import Dict, Tuple
17 GREEN_COLOR = '\x1b[32m'
18 RED_COLOR = '\x1b[31m'
21 def colorize_result(input_text):
22 if input_text is None or not sys.stdout.isatty():
24 if input_text.startswith('OK'):
27 assert(input_text.startswith('FAIL:')), f'unexpected result "{input_text}"'
29 return f'{color}{input_text}{COLOR_END}'
33 def __init__(self, reason: str, decision: str, name: str, expected: str):
34 assert(name and name == name.strip() and len(name.split()) == 1), \
35 f'invalid name "{name}" for {self.__class__.__name__}'
38 assert(decision and decision == decision.strip() and len(decision.split()) == 1), \
39 f'invalid decision "{decision}" for "{name}" check'
40 self.decision = decision
42 assert(reason and reason == reason.strip() and len(reason.split()) == 1), \
43 f'invalid reason "{reason}" for "{name}" check'
46 assert(expected and expected == expected.strip()), \
47 f'invalid expected value "{expected}" for "{name}" check (1)'
48 val_len = len(expected.split())
50 assert(expected in ('is not set', 'is not off')), \
51 f'invalid expected value "{expected}" for "{name}" check (2)'
53 assert(expected == 'is present'), \
54 f'invalid expected value "{expected}" for "{name}" check (3)'
56 assert(val_len == 1), \
57 f'invalid expected value "{expected}" for "{name}" check (4)'
58 self.expected = expected
67 def set_state(self, data):
68 assert(data is None or isinstance(data, str)), \
69 f'invalid state "{data}" for "{self.name}" check'
73 # handle the 'is present' check
74 if self.expected == 'is present':
75 if self.state is None:
76 self.result = 'FAIL: is not present'
78 self.result = 'OK: is present'
81 # handle the 'is not off' option check
82 if self.expected == 'is not off':
83 if self.state == 'off':
84 self.result = 'FAIL: is off'
85 elif self.state == '0':
86 self.result = 'FAIL: is off, "0"'
87 elif self.state is None:
88 self.result = 'FAIL: is off, not found'
90 self.result = f'OK: is not off, "{self.state}"'
93 # handle the option value check
94 if self.expected == self.state:
96 elif self.state is None:
97 if self.expected == 'is not set':
98 self.result = 'OK: is not found'
100 self.result = 'FAIL: is not found'
102 self.result = f'FAIL: "{self.state}"'
104 def table_print(self, _mode, with_results: bool):
105 print(f'{self.name:<40}|{self.opt_type:^7}|{self.expected:^12}|{self.decision:^10}|{self.reason:^18}', end='')
107 print(f'| {colorize_result(self.result)}', end='')
109 def json_dump(self, with_results: bool) -> Dict:
111 "option_name": self.name,
112 "type": self.opt_type,
113 "desired_val": self.expected,
114 "decision": self.decision,
115 "reason": self.reason,
118 dump["check_result"] = self.result
119 dump["check_result_bool"] = self.result.startswith('OK')
123 class KconfigCheck(OptCheck):
124 def __init__(self, *args, **kwargs):
125 super().__init__(*args, **kwargs)
126 self.name = f'CONFIG_{self.name}'
133 class CmdlineCheck(OptCheck):
139 class SysctlCheck(OptCheck):
146 def __init__(self, ver_expected: Tuple):
147 assert(ver_expected and isinstance(ver_expected, tuple) and len(ver_expected) == 3), \
148 f'invalid expected version "{ver_expected}" for VersionCheck (1)'
149 assert(all(map(lambda x: isinstance(x, int), ver_expected))), \
150 f'invalid expected version "{ver_expected}" for VersionCheck (2)'
151 self.ver_expected = ver_expected
159 def set_state(self, data: Tuple):
160 assert(data and isinstance(data, tuple) and len(data) >= 3), \
161 f'invalid version "{data}" for VersionCheck'
165 if self.ver[0] > self.ver_expected[0]:
166 self.result = f'OK: version >= {self.ver_expected}'
168 if self.ver[0] < self.ver_expected[0]:
169 self.result = f'FAIL: version < {self.ver_expected}'
171 # self.ver[0] and self.ver_expected[0] are equal
172 if self.ver[1] > self.ver_expected[1]:
173 self.result = f'OK: version >= {self.ver_expected}'
175 if self.ver[1] < self.ver_expected[1]:
176 self.result = f'FAIL: version < {self.ver_expected}'
178 # self.ver[1] and self.ver_expected[1] are equal too
179 if self.ver[2] >= self.ver_expected[2]:
180 self.result = f'OK: version >= {self.ver_expected}'
182 self.result = f'FAIL: version < {self.ver_expected}'
184 def table_print(self, _mode, with_results: bool):
185 ver_req = f'kernel version >= {self.ver_expected}'
186 print(f'{ver_req:<91}', end='')
188 print(f'| {colorize_result(self.result)}', end='')
191 class ComplexOptCheck:
192 def __init__(self, *opts):
195 f'empty {self.__class__.__name__} check'
196 assert(len(self.opts) != 1), \
197 f'useless {self.__class__.__name__} check: {opts}'
198 assert(isinstance(opts[0], (KconfigCheck, CmdlineCheck, SysctlCheck))), \
199 f'invalid {self.__class__.__name__} check: {opts}'
208 return self.opts[0].name
212 return self.opts[0].expected
214 def table_print(self, mode: str, with_results: bool):
215 if mode == 'verbose':
216 class_name = f'<<< {self.__class__.__name__} >>>'
217 print(f' {class_name:87}', end='')
219 print(f'| {colorize_result(self.result)}', end='')
222 o.table_print(mode, with_results)
225 o.table_print(mode, False)
227 print(f'| {colorize_result(self.result)}', end='')
229 def json_dump(self, with_results: bool) -> Dict:
230 dump = self.opts[0].json_dump(False)
232 # Add the 'check_result' and 'check_result_bool' keys to the dictionary
233 dump["check_result"] = self.result
234 dump["check_result_bool"] = self.result.startswith('OK')
238 class OR(ComplexOptCheck):
239 # self.opts[0] is the option that this OR-check is about.
241 # OR(<X_is_hardened>, <X_is_disabled>)
242 # OR(<X_is_hardened>, <old_X_is_hardened>)
244 for i, opt in enumerate(self.opts):
246 if opt.result.startswith('OK'):
247 self.result = opt.result
248 # Add more info for additional checks:
250 if opt.result == 'OK':
251 self.result = f'OK: {opt.name} is "{opt.expected}"'
252 elif opt.result == 'OK: is not found':
253 self.result = f'OK: {opt.name} is not found'
254 elif opt.result == 'OK: is present':
255 self.result = f'OK: {opt.name} is present'
256 elif opt.result.startswith('OK: is not off'):
257 self.result = f'OK: {opt.name} is not off'
259 # VersionCheck provides enough info
260 assert(opt.result.startswith('OK: version')), \
261 f'unexpected OK description "{opt.result}"'
263 self.result = self.opts[0].result
266 class AND(ComplexOptCheck):
267 # self.opts[0] is the option that this AND-check is about.
269 # AND(<suboption>, <main_option>)
270 # Suboption is not checked if checking of the main_option is failed.
271 # AND(<X_is_disabled>, <old_X_is_disabled>)
273 for i, opt in reversed(list(enumerate(self.opts))):
276 self.result = opt.result
278 if not opt.result.startswith('OK'):
279 # This FAIL is caused by additional checks,
280 # and not by the main option that this AND-check is about.
281 # Describe the reason of the FAIL.
282 if opt.result.startswith('FAIL: \"') or opt.result == 'FAIL: is not found':
283 self.result = f'FAIL: {opt.name} is not "{opt.expected}"'
284 elif opt.result == 'FAIL: is not present':
285 self.result = f'FAIL: {opt.name} is not present'
286 elif opt.result in ('FAIL: is off', 'FAIL: is off, "0"'):
287 self.result = f'FAIL: {opt.name} is off'
288 elif opt.result == 'FAIL: is off, not found':
289 self.result = f'FAIL: {opt.name} is off, not found'
291 # VersionCheck provides enough info
292 self.result = opt.result
293 assert(opt.result.startswith('FAIL: version')), \
294 f'unexpected FAIL description "{opt.result}"'
298 SIMPLE_OPTION_TYPES = ('kconfig', 'cmdline', 'sysctl', 'version')
301 def populate_simple_opt_with_data(opt, data, data_type: str):
302 assert(opt.opt_type != 'complex'), \
303 f'unexpected ComplexOptCheck "{opt.name}"'
304 assert(opt.opt_type in SIMPLE_OPTION_TYPES), \
305 f'invalid opt_type "{opt.opt_type}"'
306 assert(data_type in SIMPLE_OPTION_TYPES), \
307 f'invalid data_type "{data_type}"'
311 if data_type != opt.opt_type:
314 if data_type in ('kconfig', 'cmdline', 'sysctl'):
315 opt.set_state(data.get(opt.name, None))
317 assert(data_type == 'version'), \
318 f'unexpected data_type "{data_type}"'
322 def populate_opt_with_data(opt, data, data_type):
323 assert(opt.opt_type != 'version'), 'a single VersionCheck is useless'
324 if opt.opt_type != 'complex':
325 populate_simple_opt_with_data(opt, data, data_type)
328 if o.opt_type != 'complex':
329 populate_simple_opt_with_data(o, data, data_type)
331 # Recursion for nested ComplexOptCheck objects
332 populate_opt_with_data(o, data, data_type)
335 def populate_with_data(checklist, data, data_type):
336 for opt in checklist:
337 populate_opt_with_data(opt, data, data_type)
340 def override_expected_value(checklist, name, new_val):
341 for opt in checklist:
343 assert(opt.opt_type in ('kconfig', 'cmdline', 'sysctl')), \
344 f'overriding an expected value for "{opt.opt_type}" checks is not supported yet'
345 opt.expected = new_val
348 def perform_checks(checklist):
349 for opt in checklist: