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 GREEN_COLOR = '\x1b[32m'
15 RED_COLOR = '\x1b[31m'
18 def colorize_result(input_text):
19 if input_text is None:
21 if input_text.startswith('OK'):
24 assert(input_text.startswith('FAIL:')), f'unexpected result "{input_text}"'
26 return f'{color}{input_text}{COLOR_END}'
30 def __init__(self, reason, decision, name, expected):
31 assert(name and name == name.strip() and len(name.split()) == 1), \
32 f'invalid name "{name}" for {self.__class__.__name__}'
35 assert(decision and decision == decision.strip() and len(decision.split()) == 1), \
36 f'invalid decision "{decision}" for "{name}" check'
37 self.decision = decision
39 assert(reason and reason == reason.strip() and len(reason.split()) == 1), \
40 f'invalid reason "{reason}" for "{name}" check'
43 assert(expected and expected == expected.strip()), \
44 f'invalid expected value "{expected}" for "{name}" check (1)'
45 val_len = len(expected.split())
47 assert(expected in ('is not set', 'is not off')), \
48 f'invalid expected value "{expected}" for "{name}" check (2)'
50 assert(expected == 'is present'), \
51 f'invalid expected value "{expected}" for "{name}" check (3)'
53 assert(val_len == 1), \
54 f'invalid expected value "{expected}" for "{name}" check (4)'
55 self.expected = expected
65 # handle the 'is present' check
66 if self.expected == 'is present':
67 if self.state is None:
68 self.result = 'FAIL: is not present'
70 self.result = 'OK: is present'
73 # handle the 'is not off' option check
74 if self.expected == 'is not off':
75 if self.state == 'off':
76 self.result = 'FAIL: is off'
77 elif self.state == '0':
78 self.result = 'FAIL: is off, "0"'
79 elif self.state is None:
80 self.result = 'FAIL: is off, not found'
82 self.result = f'OK: is not off, "{self.state}"'
85 # handle the option value check
86 if self.expected == self.state:
88 elif self.state is None:
89 if self.expected == 'is not set':
90 self.result = 'OK: is not found'
92 self.result = 'FAIL: is not found'
94 self.result = f'FAIL: "{self.state}"'
96 def table_print(self, _mode, with_results):
97 print(f'{self.name:<40}|{self.type:^7}|{self.expected:^12}|{self.decision:^10}|{self.reason:^18}', end='')
99 print(f'| {colorize_result(self.result)}', end='')
101 def json_dump(self, with_results):
102 dump = [self.name, self.type, self.expected, self.decision, self.reason]
104 dump.append(self.result)
108 class KconfigCheck(OptCheck):
109 def __init__(self, *args, **kwargs):
110 super().__init__(*args, **kwargs)
111 self.name = f'CONFIG_{self.name}'
118 class CmdlineCheck(OptCheck):
124 class SysctlCheck(OptCheck):
131 def __init__(self, ver_expected):
132 assert(ver_expected and isinstance(ver_expected, tuple) and len(ver_expected) == 2), \
133 f'invalid version "{ver_expected}" for VersionCheck'
134 self.ver_expected = ver_expected
143 if self.ver[0] > self.ver_expected[0]:
144 self.result = f'OK: version >= {self.ver_expected[0]}.{self.ver_expected[1]}'
146 if self.ver[0] < self.ver_expected[0]:
147 self.result = f'FAIL: version < {self.ver_expected[0]}.{self.ver_expected[1]}'
149 if self.ver[1] >= self.ver_expected[1]:
150 self.result = f'OK: version >= {self.ver_expected[0]}.{self.ver_expected[1]}'
152 self.result = f'FAIL: version < {self.ver_expected[0]}.{self.ver_expected[1]}'
154 def table_print(self, _mode, with_results):
155 ver_req = f'kernel version >= {self.ver_expected[0]}.{self.ver_expected[1]}'
156 print(f'{ver_req:<91}', end='')
158 print(f'| {colorize_result(self.result)}', end='')
161 class ComplexOptCheck:
162 def __init__(self, *opts):
165 f'empty {self.__class__.__name__} check'
166 assert(len(self.opts) != 1), \
167 f'useless {self.__class__.__name__} check: {opts}'
168 assert(isinstance(opts[0], (KconfigCheck, CmdlineCheck, SysctlCheck))), \
169 f'invalid {self.__class__.__name__} check: {opts}'
178 return self.opts[0].name
182 return self.opts[0].expected
184 def table_print(self, mode, with_results):
185 if mode == 'verbose':
186 class_name = f'<<< {self.__class__.__name__} >>>'
187 print(f' {class_name:87}', end='')
189 print(f'| {colorize_result(self.result)}', end='')
192 o.table_print(mode, with_results)
195 o.table_print(mode, False)
197 print(f'| {colorize_result(self.result)}', end='')
199 def json_dump(self, with_results):
200 dump = self.opts[0].json_dump(False)
202 dump.append(self.result)
206 class OR(ComplexOptCheck):
207 # self.opts[0] is the option that this OR-check is about.
209 # OR(<X_is_hardened>, <X_is_disabled>)
210 # OR(<X_is_hardened>, <old_X_is_hardened>)
212 for i, opt in enumerate(self.opts):
214 if opt.result.startswith('OK'):
215 self.result = opt.result
216 # Add more info for additional checks:
218 if opt.result == 'OK':
219 self.result = f'OK: {opt.name} is "{opt.expected}"'
220 elif opt.result == 'OK: is not found':
221 self.result = f'OK: {opt.name} is not found'
222 elif opt.result == 'OK: is present':
223 self.result = f'OK: {opt.name} is present'
224 elif opt.result.startswith('OK: is not off'):
225 self.result = f'OK: {opt.name} is not off'
227 # VersionCheck provides enough info
228 assert(opt.result.startswith('OK: version')), \
229 f'unexpected OK description "{opt.result}"'
231 self.result = self.opts[0].result
234 class AND(ComplexOptCheck):
235 # self.opts[0] is the option that this AND-check is about.
237 # AND(<suboption>, <main_option>)
238 # Suboption is not checked if checking of the main_option is failed.
239 # AND(<X_is_disabled>, <old_X_is_disabled>)
241 for i, opt in reversed(list(enumerate(self.opts))):
244 self.result = opt.result
246 if not opt.result.startswith('OK'):
247 # This FAIL is caused by additional checks,
248 # and not by the main option that this AND-check is about.
249 # Describe the reason of the FAIL.
250 if opt.result.startswith('FAIL: \"') or opt.result == 'FAIL: is not found':
251 self.result = f'FAIL: {opt.name} is not "{opt.expected}"'
252 elif opt.result == 'FAIL: is not present':
253 self.result = f'FAIL: {opt.name} is not present'
254 elif opt.result in ('FAIL: is off', 'FAIL: is off, "0"'):
255 self.result = f'FAIL: {opt.name} is off'
256 elif opt.result == 'FAIL: is off, not found':
257 self.result = f'FAIL: {opt.name} is off, not found'
259 # VersionCheck provides enough info
260 self.result = opt.result
261 assert(opt.result.startswith('FAIL: version')), \
262 f'unexpected FAIL description "{opt.result}"'
266 SIMPLE_OPTION_TYPES = ('kconfig', 'cmdline', 'sysctl', 'version')
269 def populate_simple_opt_with_data(opt, data, data_type):
270 assert(opt.type != 'complex'), \
271 f'unexpected ComplexOptCheck "{opt.name}"'
272 assert(opt.type in SIMPLE_OPTION_TYPES), \
273 f'invalid opt type "{opt.type}"'
274 assert(data_type in SIMPLE_OPTION_TYPES), \
275 f'invalid data type "{data_type}"'
279 if data_type != opt.type:
282 if data_type in ('kconfig', 'cmdline', 'sysctl'):
283 opt.state = data.get(opt.name, None)
285 assert(data_type == 'version'), \
286 f'unexpected data type "{data_type}"'
290 def populate_opt_with_data(opt, data, data_type):
291 assert(opt.type != 'version'), 'a single VersionCheck is useless'
292 if opt.type != 'complex':
293 populate_simple_opt_with_data(opt, data, data_type)
296 if o.type != 'complex':
297 populate_simple_opt_with_data(o, data, data_type)
299 # Recursion for nested ComplexOptCheck objects
300 populate_opt_with_data(o, data, data_type)
303 def populate_with_data(checklist, data, data_type):
304 for opt in checklist:
305 populate_opt_with_data(opt, data, data_type)
308 def override_expected_value(checklist, name, new_val):
309 for opt in checklist:
311 assert(opt.type in ('kconfig', 'cmdline', 'sysctl')), \
312 f'overriding an expected value for "{opt.type}" checks is not supported yet'
313 opt.expected = new_val
316 def perform_checks(checklist):
317 for opt in checklist: