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 = '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 print(f' {"<<< " + self.__class__.__name__ + " >>>":87}', end='')
188 print(f'| {colorize_result(self.result)}', end='')
191 o.table_print(mode, with_results)
194 o.table_print(mode, False)
196 print(f'| {colorize_result(self.result)}', end='')
198 def json_dump(self, with_results):
199 dump = self.opts[0].json_dump(False)
201 dump.append(self.result)
205 class OR(ComplexOptCheck):
206 # self.opts[0] is the option that this OR-check is about.
208 # OR(<X_is_hardened>, <X_is_disabled>)
209 # OR(<X_is_hardened>, <old_X_is_hardened>)
211 for i, opt in enumerate(self.opts):
213 if opt.result.startswith('OK'):
214 self.result = opt.result
215 # Add more info for additional checks:
217 if opt.result == 'OK':
218 self.result = f'OK: {opt.name} is "{opt.expected}"'
219 elif opt.result == 'OK: is not found':
220 self.result = f'OK: {opt.name} is not found'
221 elif opt.result == 'OK: is present':
222 self.result = f'OK: {opt.name} is present'
223 elif opt.result.startswith('OK: is not off'):
224 self.result = f'OK: {opt.name} is not off'
226 # VersionCheck provides enough info
227 assert(opt.result.startswith('OK: version')), \
228 f'unexpected OK description "{opt.result}"'
230 self.result = self.opts[0].result
233 class AND(ComplexOptCheck):
234 # self.opts[0] is the option that this AND-check is about.
236 # AND(<suboption>, <main_option>)
237 # Suboption is not checked if checking of the main_option is failed.
238 # AND(<X_is_disabled>, <old_X_is_disabled>)
240 for i, opt in reversed(list(enumerate(self.opts))):
243 self.result = opt.result
245 if not opt.result.startswith('OK'):
246 # This FAIL is caused by additional checks,
247 # and not by the main option that this AND-check is about.
248 # Describe the reason of the FAIL.
249 if opt.result.startswith('FAIL: \"') or opt.result == 'FAIL: is not found':
250 self.result = f'FAIL: {opt.name} is not "{opt.expected}"'
251 elif opt.result == 'FAIL: is not present':
252 self.result = f'FAIL: {opt.name} is not present'
253 elif opt.result in ('FAIL: is off', 'FAIL: is off, "0"'):
254 self.result = f'FAIL: {opt.name} is off'
255 elif opt.result == 'FAIL: is off, not found':
256 self.result = f'FAIL: {opt.name} is off, not found'
258 # VersionCheck provides enough info
259 self.result = opt.result
260 assert(opt.result.startswith('FAIL: version')), \
261 f'unexpected FAIL description "{opt.result}"'
265 SIMPLE_OPTION_TYPES = ('kconfig', 'cmdline', 'sysctl', 'version')
268 def populate_simple_opt_with_data(opt, data, data_type):
269 assert(opt.type != 'complex'), \
270 f'unexpected ComplexOptCheck "{opt.name}"'
271 assert(opt.type in SIMPLE_OPTION_TYPES), \
272 f'invalid opt type "{opt.type}"'
273 assert(data_type in SIMPLE_OPTION_TYPES), \
274 f'invalid data type "{data_type}"'
278 if data_type != opt.type:
281 if data_type in ('kconfig', 'cmdline', 'sysctl'):
282 opt.state = data.get(opt.name, None)
284 assert(data_type == 'version'), \
285 f'unexpected data type "{data_type}"'
289 def populate_opt_with_data(opt, data, data_type):
290 assert(opt.type != 'version'), 'a single VersionCheck is useless'
291 if opt.type != 'complex':
292 populate_simple_opt_with_data(opt, data, data_type)
295 if o.type != 'complex':
296 populate_simple_opt_with_data(o, data, data_type)
298 # Recursion for nested ComplexOptCheck objects
299 populate_opt_with_data(o, data, data_type)
302 def populate_with_data(checklist, data, data_type):
303 for opt in checklist:
304 populate_opt_with_data(opt, data, data_type)
307 def override_expected_value(checklist, name, new_val):
308 for opt in checklist:
310 assert(opt.type in ('kconfig', 'cmdline', 'sysctl')), \
311 f'overriding an expected value for "{opt.type}" checks is not supported yet'
312 opt.expected = new_val
315 def perform_checks(checklist):
316 for opt in checklist: