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
64 def set_state(self, data):
65 assert(data is None or isinstance(data, str)), \
66 f'invalid state "{data}" for "{self.name}" check'
70 # handle the 'is present' check
71 if self.expected == 'is present':
72 if self.state is None:
73 self.result = 'FAIL: is not present'
75 self.result = 'OK: is present'
78 # handle the 'is not off' option check
79 if self.expected == 'is not off':
80 if self.state == 'off':
81 self.result = 'FAIL: is off'
82 elif self.state == '0':
83 self.result = 'FAIL: is off, "0"'
84 elif self.state is None:
85 self.result = 'FAIL: is off, not found'
87 self.result = f'OK: is not off, "{self.state}"'
90 # handle the option value check
91 if self.expected == self.state:
93 elif self.state is None:
94 if self.expected == 'is not set':
95 self.result = 'OK: is not found'
97 self.result = 'FAIL: is not found'
99 self.result = f'FAIL: "{self.state}"'
101 def table_print(self, _mode, with_results):
102 print(f'{self.name:<40}|{self.type:^7}|{self.expected:^12}|{self.decision:^10}|{self.reason:^18}', end='')
104 print(f'| {colorize_result(self.result)}', end='')
106 def json_dump(self, with_results):
107 dump = [self.name, self.type, self.expected, self.decision, self.reason]
109 dump.append(self.result)
113 class KconfigCheck(OptCheck):
114 def __init__(self, *args, **kwargs):
115 super().__init__(*args, **kwargs)
116 self.name = f'CONFIG_{self.name}'
123 class CmdlineCheck(OptCheck):
129 class SysctlCheck(OptCheck):
136 def __init__(self, ver_expected):
137 assert(ver_expected and isinstance(ver_expected, tuple) and len(ver_expected) == 3), \
138 f'invalid expected version "{ver_expected}" for VersionCheck'
139 self.ver_expected = ver_expected
147 def set_state(self, data):
148 assert(data and isinstance(data, tuple) and len(data) >= 3), \
149 f'invalid version "{data}" for VersionCheck'
153 if self.ver[0] > self.ver_expected[0]:
154 self.result = f'OK: version >= {self.ver_expected[0]}.{self.ver_expected[1]}'
156 if self.ver[0] < self.ver_expected[0]:
157 self.result = f'FAIL: version < {self.ver_expected[0]}.{self.ver_expected[1]}'
159 if self.ver[1] >= self.ver_expected[1]:
160 self.result = f'OK: version >= {self.ver_expected[0]}.{self.ver_expected[1]}'
162 self.result = f'FAIL: version < {self.ver_expected[0]}.{self.ver_expected[1]}'
164 def table_print(self, _mode, with_results):
165 ver_req = f'kernel version >= {self.ver_expected[0]}.{self.ver_expected[1]}'
166 print(f'{ver_req:<91}', end='')
168 print(f'| {colorize_result(self.result)}', end='')
171 class ComplexOptCheck:
172 def __init__(self, *opts):
175 f'empty {self.__class__.__name__} check'
176 assert(len(self.opts) != 1), \
177 f'useless {self.__class__.__name__} check: {opts}'
178 assert(isinstance(opts[0], (KconfigCheck, CmdlineCheck, SysctlCheck))), \
179 f'invalid {self.__class__.__name__} check: {opts}'
188 return self.opts[0].name
192 return self.opts[0].expected
194 def table_print(self, mode, with_results):
195 if mode == 'verbose':
196 class_name = f'<<< {self.__class__.__name__} >>>'
197 print(f' {class_name:87}', end='')
199 print(f'| {colorize_result(self.result)}', end='')
202 o.table_print(mode, with_results)
205 o.table_print(mode, False)
207 print(f'| {colorize_result(self.result)}', end='')
209 def json_dump(self, with_results):
210 dump = self.opts[0].json_dump(False)
212 dump.append(self.result)
216 class OR(ComplexOptCheck):
217 # self.opts[0] is the option that this OR-check is about.
219 # OR(<X_is_hardened>, <X_is_disabled>)
220 # OR(<X_is_hardened>, <old_X_is_hardened>)
222 for i, opt in enumerate(self.opts):
224 if opt.result.startswith('OK'):
225 self.result = opt.result
226 # Add more info for additional checks:
228 if opt.result == 'OK':
229 self.result = f'OK: {opt.name} is "{opt.expected}"'
230 elif opt.result == 'OK: is not found':
231 self.result = f'OK: {opt.name} is not found'
232 elif opt.result == 'OK: is present':
233 self.result = f'OK: {opt.name} is present'
234 elif opt.result.startswith('OK: is not off'):
235 self.result = f'OK: {opt.name} is not off'
237 # VersionCheck provides enough info
238 assert(opt.result.startswith('OK: version')), \
239 f'unexpected OK description "{opt.result}"'
241 self.result = self.opts[0].result
244 class AND(ComplexOptCheck):
245 # self.opts[0] is the option that this AND-check is about.
247 # AND(<suboption>, <main_option>)
248 # Suboption is not checked if checking of the main_option is failed.
249 # AND(<X_is_disabled>, <old_X_is_disabled>)
251 for i, opt in reversed(list(enumerate(self.opts))):
254 self.result = opt.result
256 if not opt.result.startswith('OK'):
257 # This FAIL is caused by additional checks,
258 # and not by the main option that this AND-check is about.
259 # Describe the reason of the FAIL.
260 if opt.result.startswith('FAIL: \"') or opt.result == 'FAIL: is not found':
261 self.result = f'FAIL: {opt.name} is not "{opt.expected}"'
262 elif opt.result == 'FAIL: is not present':
263 self.result = f'FAIL: {opt.name} is not present'
264 elif opt.result in ('FAIL: is off', 'FAIL: is off, "0"'):
265 self.result = f'FAIL: {opt.name} is off'
266 elif opt.result == 'FAIL: is off, not found':
267 self.result = f'FAIL: {opt.name} is off, not found'
269 # VersionCheck provides enough info
270 self.result = opt.result
271 assert(opt.result.startswith('FAIL: version')), \
272 f'unexpected FAIL description "{opt.result}"'
276 SIMPLE_OPTION_TYPES = ('kconfig', 'cmdline', 'sysctl', 'version')
279 def populate_simple_opt_with_data(opt, data, data_type):
280 assert(opt.type != 'complex'), \
281 f'unexpected ComplexOptCheck "{opt.name}"'
282 assert(opt.type in SIMPLE_OPTION_TYPES), \
283 f'invalid opt type "{opt.type}"'
284 assert(data_type in SIMPLE_OPTION_TYPES), \
285 f'invalid data type "{data_type}"'
289 if data_type != opt.type:
292 if data_type in ('kconfig', 'cmdline', 'sysctl'):
293 opt.set_state(data.get(opt.name, None))
295 assert(data_type == 'version'), \
296 f'unexpected data type "{data_type}"'
300 def populate_opt_with_data(opt, data, data_type):
301 assert(opt.type != 'version'), 'a single VersionCheck is useless'
302 if opt.type != 'complex':
303 populate_simple_opt_with_data(opt, data, data_type)
306 if o.type != 'complex':
307 populate_simple_opt_with_data(o, data, data_type)
309 # Recursion for nested ComplexOptCheck objects
310 populate_opt_with_data(o, data, data_type)
313 def populate_with_data(checklist, data, data_type):
314 for opt in checklist:
315 populate_opt_with_data(opt, data, data_type)
318 def override_expected_value(checklist, name, new_val):
319 for opt in checklist:
321 assert(opt.type in ('kconfig', 'cmdline', 'sysctl')), \
322 f'overriding an expected value for "{opt.type}" checks is not supported yet'
323 opt.expected = new_val
326 def perform_checks(checklist):
327 for opt in checklist: