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 assert self.result, f'unexpected empty result in {self.name}'
119 dump["check_result"] = self.result
120 dump["check_result_bool"] = self.result.startswith('OK')
124 class KconfigCheck(OptCheck):
125 def __init__(self, *args, **kwargs):
126 super().__init__(*args, **kwargs)
127 self.name = f'CONFIG_{self.name}'
134 class CmdlineCheck(OptCheck):
140 class SysctlCheck(OptCheck):
147 def __init__(self, ver_expected: Tuple):
148 assert(ver_expected and isinstance(ver_expected, tuple) and len(ver_expected) == 3), \
149 f'invalid expected version "{ver_expected}" for VersionCheck (1)'
150 assert(all(map(lambda x: isinstance(x, int), ver_expected))), \
151 f'invalid expected version "{ver_expected}" for VersionCheck (2)'
152 self.ver_expected = ver_expected
160 def set_state(self, data: Tuple):
161 assert(data and isinstance(data, tuple) and len(data) >= 3), \
162 f'invalid version "{data}" for VersionCheck'
166 if self.ver[0] > self.ver_expected[0]:
167 self.result = f'OK: version >= {self.ver_expected}'
169 if self.ver[0] < self.ver_expected[0]:
170 self.result = f'FAIL: version < {self.ver_expected}'
172 # self.ver[0] and self.ver_expected[0] are equal
173 if self.ver[1] > self.ver_expected[1]:
174 self.result = f'OK: version >= {self.ver_expected}'
176 if self.ver[1] < self.ver_expected[1]:
177 self.result = f'FAIL: version < {self.ver_expected}'
179 # self.ver[1] and self.ver_expected[1] are equal too
180 if self.ver[2] >= self.ver_expected[2]:
181 self.result = f'OK: version >= {self.ver_expected}'
183 self.result = f'FAIL: version < {self.ver_expected}'
185 def table_print(self, _mode, with_results: bool):
186 ver_req = f'kernel version >= {self.ver_expected}'
187 print(f'{ver_req:<91}', end='')
189 print(f'| {colorize_result(self.result)}', end='')
192 class ComplexOptCheck:
193 def __init__(self, *opts):
196 f'empty {self.__class__.__name__} check'
197 assert(len(self.opts) != 1), \
198 f'useless {self.__class__.__name__} check: {opts}'
199 assert(isinstance(opts[0], (KconfigCheck, CmdlineCheck, SysctlCheck))), \
200 f'invalid {self.__class__.__name__} check: {opts}'
209 return self.opts[0].name
213 return self.opts[0].expected
215 def table_print(self, mode: str, with_results: bool):
216 if mode == 'verbose':
217 class_name = f'<<< {self.__class__.__name__} >>>'
218 print(f' {class_name:87}', end='')
220 print(f'| {colorize_result(self.result)}', end='')
223 o.table_print(mode, with_results)
226 o.table_print(mode, False)
228 print(f'| {colorize_result(self.result)}', end='')
230 def json_dump(self, with_results: bool) -> Dict:
231 dump = self.opts[0].json_dump(False)
233 # Add the 'check_result' and 'check_result_bool' keys to the dictionary
234 assert self.result, f'unexpected empty result in {self.name}'
235 dump["check_result"] = self.result
236 dump["check_result_bool"] = self.result.startswith('OK')
240 class OR(ComplexOptCheck):
241 # self.opts[0] is the option that this OR-check is about.
243 # OR(<X_is_hardened>, <X_is_disabled>)
244 # OR(<X_is_hardened>, <old_X_is_hardened>)
246 for i, opt in enumerate(self.opts):
248 if opt.result.startswith('OK'):
249 self.result = opt.result
250 # Add more info for additional checks:
252 if opt.result == 'OK':
253 self.result = f'OK: {opt.name} is "{opt.expected}"'
254 elif opt.result == 'OK: is not found':
255 self.result = f'OK: {opt.name} is not found'
256 elif opt.result == 'OK: is present':
257 self.result = f'OK: {opt.name} is present'
258 elif opt.result.startswith('OK: is not off'):
259 self.result = f'OK: {opt.name} is not off'
261 # VersionCheck provides enough info
262 assert(opt.result.startswith('OK: version')), \
263 f'unexpected OK description "{opt.result}"'
265 self.result = self.opts[0].result
268 class AND(ComplexOptCheck):
269 # self.opts[0] is the option that this AND-check is about.
271 # AND(<suboption>, <main_option>)
272 # Suboption is not checked if checking of the main_option is failed.
273 # AND(<X_is_disabled>, <old_X_is_disabled>)
275 for i, opt in reversed(list(enumerate(self.opts))):
278 self.result = opt.result
280 if not opt.result.startswith('OK'):
281 # This FAIL is caused by additional checks,
282 # and not by the main option that this AND-check is about.
283 # Describe the reason of the FAIL.
284 if opt.result.startswith('FAIL: \"') or opt.result == 'FAIL: is not found':
285 self.result = f'FAIL: {opt.name} is not "{opt.expected}"'
286 elif opt.result == 'FAIL: is not present':
287 self.result = f'FAIL: {opt.name} is not present'
288 elif opt.result in ('FAIL: is off', 'FAIL: is off, "0"'):
289 self.result = f'FAIL: {opt.name} is off'
290 elif opt.result == 'FAIL: is off, not found':
291 self.result = f'FAIL: {opt.name} is off, not found'
293 # VersionCheck provides enough info
294 self.result = opt.result
295 assert(opt.result.startswith('FAIL: version')), \
296 f'unexpected FAIL description "{opt.result}"'
300 SIMPLE_OPTION_TYPES = ('kconfig', 'cmdline', 'sysctl', 'version')
303 def populate_simple_opt_with_data(opt, data, data_type: str):
304 assert(opt.opt_type != 'complex'), \
305 f'unexpected ComplexOptCheck "{opt.name}"'
306 assert(opt.opt_type in SIMPLE_OPTION_TYPES), \
307 f'invalid opt_type "{opt.opt_type}"'
308 assert(data_type in SIMPLE_OPTION_TYPES), \
309 f'invalid data_type "{data_type}"'
313 if data_type != opt.opt_type:
316 if data_type in ('kconfig', 'cmdline', 'sysctl'):
317 opt.set_state(data.get(opt.name, None))
319 assert(data_type == 'version'), \
320 f'unexpected data_type "{data_type}"'
324 def populate_opt_with_data(opt, data, data_type):
325 assert(opt.opt_type != 'version'), 'a single VersionCheck is useless'
326 if opt.opt_type != 'complex':
327 populate_simple_opt_with_data(opt, data, data_type)
330 if o.opt_type != 'complex':
331 populate_simple_opt_with_data(o, data, data_type)
333 # Recursion for nested ComplexOptCheck objects
334 populate_opt_with_data(o, data, data_type)
337 def populate_with_data(checklist, data, data_type):
338 for opt in checklist:
339 populate_opt_with_data(opt, data, data_type)
342 def override_expected_value(checklist, name, new_val):
343 for opt in checklist:
345 assert(opt.opt_type in ('kconfig', 'cmdline', 'sysctl')), \
346 f'overriding an expected value for "{opt.opt_type}" checks is not supported yet'
347 opt.expected = new_val
350 def perform_checks(checklist):
351 for opt in checklist: