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):
66 assert(isinstance(data, str)), \
67 f'invalid state "{data}" for "{self.name}" check'
71 # handle the 'is present' check
72 if self.expected == 'is present':
73 if self.state is None:
74 self.result = 'FAIL: is not present'
76 self.result = 'OK: is present'
79 # handle the 'is not off' option check
80 if self.expected == 'is not off':
81 if self.state == 'off':
82 self.result = 'FAIL: is off'
83 elif self.state == '0':
84 self.result = 'FAIL: is off, "0"'
85 elif self.state is None:
86 self.result = 'FAIL: is off, not found'
88 self.result = f'OK: is not off, "{self.state}"'
91 # handle the option value check
92 if self.expected == self.state:
94 elif self.state is None:
95 if self.expected == 'is not set':
96 self.result = 'OK: is not found'
98 self.result = 'FAIL: is not found'
100 self.result = f'FAIL: "{self.state}"'
102 def table_print(self, _mode, with_results):
103 print(f'{self.name:<40}|{self.type:^7}|{self.expected:^12}|{self.decision:^10}|{self.reason:^18}', end='')
105 print(f'| {colorize_result(self.result)}', end='')
107 def json_dump(self, with_results):
108 dump = [self.name, self.type, self.expected, self.decision, self.reason]
110 dump.append(self.result)
114 class KconfigCheck(OptCheck):
115 def __init__(self, *args, **kwargs):
116 super().__init__(*args, **kwargs)
117 self.name = f'CONFIG_{self.name}'
124 class CmdlineCheck(OptCheck):
130 class SysctlCheck(OptCheck):
137 def __init__(self, ver_expected):
138 assert(ver_expected and isinstance(ver_expected, tuple) and len(ver_expected) == 3), \
139 f'invalid expected version "{ver_expected}" for VersionCheck'
140 self.ver_expected = ver_expected
148 def set_state(self, data):
149 assert(data and isinstance(data, tuple) and len(data) >= 3), \
150 f'invalid version "{data}" for VersionCheck'
154 if self.ver[0] > self.ver_expected[0]:
155 self.result = f'OK: version >= {self.ver_expected[0]}.{self.ver_expected[1]}'
157 if self.ver[0] < self.ver_expected[0]:
158 self.result = f'FAIL: version < {self.ver_expected[0]}.{self.ver_expected[1]}'
160 if self.ver[1] >= self.ver_expected[1]:
161 self.result = f'OK: version >= {self.ver_expected[0]}.{self.ver_expected[1]}'
163 self.result = f'FAIL: version < {self.ver_expected[0]}.{self.ver_expected[1]}'
165 def table_print(self, _mode, with_results):
166 ver_req = f'kernel version >= {self.ver_expected[0]}.{self.ver_expected[1]}'
167 print(f'{ver_req:<91}', end='')
169 print(f'| {colorize_result(self.result)}', end='')
172 class ComplexOptCheck:
173 def __init__(self, *opts):
176 f'empty {self.__class__.__name__} check'
177 assert(len(self.opts) != 1), \
178 f'useless {self.__class__.__name__} check: {opts}'
179 assert(isinstance(opts[0], (KconfigCheck, CmdlineCheck, SysctlCheck))), \
180 f'invalid {self.__class__.__name__} check: {opts}'
189 return self.opts[0].name
193 return self.opts[0].expected
195 def table_print(self, mode, with_results):
196 if mode == 'verbose':
197 class_name = f'<<< {self.__class__.__name__} >>>'
198 print(f' {class_name:87}', end='')
200 print(f'| {colorize_result(self.result)}', end='')
203 o.table_print(mode, with_results)
206 o.table_print(mode, False)
208 print(f'| {colorize_result(self.result)}', end='')
210 def json_dump(self, with_results):
211 dump = self.opts[0].json_dump(False)
213 dump.append(self.result)
217 class OR(ComplexOptCheck):
218 # self.opts[0] is the option that this OR-check is about.
220 # OR(<X_is_hardened>, <X_is_disabled>)
221 # OR(<X_is_hardened>, <old_X_is_hardened>)
223 for i, opt in enumerate(self.opts):
225 if opt.result.startswith('OK'):
226 self.result = opt.result
227 # Add more info for additional checks:
229 if opt.result == 'OK':
230 self.result = f'OK: {opt.name} is "{opt.expected}"'
231 elif opt.result == 'OK: is not found':
232 self.result = f'OK: {opt.name} is not found'
233 elif opt.result == 'OK: is present':
234 self.result = f'OK: {opt.name} is present'
235 elif opt.result.startswith('OK: is not off'):
236 self.result = f'OK: {opt.name} is not off'
238 # VersionCheck provides enough info
239 assert(opt.result.startswith('OK: version')), \
240 f'unexpected OK description "{opt.result}"'
242 self.result = self.opts[0].result
245 class AND(ComplexOptCheck):
246 # self.opts[0] is the option that this AND-check is about.
248 # AND(<suboption>, <main_option>)
249 # Suboption is not checked if checking of the main_option is failed.
250 # AND(<X_is_disabled>, <old_X_is_disabled>)
252 for i, opt in reversed(list(enumerate(self.opts))):
255 self.result = opt.result
257 if not opt.result.startswith('OK'):
258 # This FAIL is caused by additional checks,
259 # and not by the main option that this AND-check is about.
260 # Describe the reason of the FAIL.
261 if opt.result.startswith('FAIL: \"') or opt.result == 'FAIL: is not found':
262 self.result = f'FAIL: {opt.name} is not "{opt.expected}"'
263 elif opt.result == 'FAIL: is not present':
264 self.result = f'FAIL: {opt.name} is not present'
265 elif opt.result in ('FAIL: is off', 'FAIL: is off, "0"'):
266 self.result = f'FAIL: {opt.name} is off'
267 elif opt.result == 'FAIL: is off, not found':
268 self.result = f'FAIL: {opt.name} is off, not found'
270 # VersionCheck provides enough info
271 self.result = opt.result
272 assert(opt.result.startswith('FAIL: version')), \
273 f'unexpected FAIL description "{opt.result}"'
277 SIMPLE_OPTION_TYPES = ('kconfig', 'cmdline', 'sysctl', 'version')
280 def populate_simple_opt_with_data(opt, data, data_type):
281 assert(opt.type != 'complex'), \
282 f'unexpected ComplexOptCheck "{opt.name}"'
283 assert(opt.type in SIMPLE_OPTION_TYPES), \
284 f'invalid opt type "{opt.type}"'
285 assert(data_type in SIMPLE_OPTION_TYPES), \
286 f'invalid data type "{data_type}"'
290 if data_type != opt.type:
293 if data_type in ('kconfig', 'cmdline', 'sysctl'):
294 opt.set_state(data.get(opt.name, None))
296 assert(data_type == 'version'), \
297 f'unexpected data type "{data_type}"'
301 def populate_opt_with_data(opt, data, data_type):
302 assert(opt.type != 'version'), 'a single VersionCheck is useless'
303 if opt.type != 'complex':
304 populate_simple_opt_with_data(opt, data, data_type)
307 if o.type != 'complex':
308 populate_simple_opt_with_data(o, data, data_type)
310 # Recursion for nested ComplexOptCheck objects
311 populate_opt_with_data(o, data, data_type)
314 def populate_with_data(checklist, data, data_type):
315 for opt in checklist:
316 populate_opt_with_data(opt, data, data_type)
319 def override_expected_value(checklist, name, new_val):
320 for opt in checklist:
322 assert(opt.type in ('kconfig', 'cmdline', 'sysctl')), \
323 f'overriding an expected value for "{opt.type}" checks is not supported yet'
324 opt.expected = new_val
327 def perform_checks(checklist):
328 for opt in checklist: