X-Git-Url: https://jxself.org/git/?a=blobdiff_plain;f=kernel_hardening_checker%2F__init__.py;h=3a30aefca388f48ee5e31343fbeab0d76e67fbef;hb=5a977616f26cdaa334a71bc56265e117b9036a05;hp=4d5aaca7989dde7572e8d10a5716bb2168ad44fe;hpb=35f90af9096a0dad868107ea6dc005468badd5c3;p=kconfig-hardened-check.git diff --git a/kernel_hardening_checker/__init__.py b/kernel_hardening_checker/__init__.py index 4d5aaca..3a30aef 100644 --- a/kernel_hardening_checker/__init__.py +++ b/kernel_hardening_checker/__init__.py @@ -1,4 +1,4 @@ -#!/usr/bin/python3 +#!/usr/bin/env python3 """ This tool is for checking the security hardening options of the Linux kernel. @@ -14,24 +14,23 @@ import gzip import sys from argparse import ArgumentParser from collections import OrderedDict +from typing import List, Tuple, OrderedDict, TextIO import re import json from .__about__ import __version__ from .checks import add_kconfig_checks, add_cmdline_checks, normalize_cmdline_options, add_sysctl_checks -from .engine import populate_with_data, perform_checks, override_expected_value +from .engine import StrOrNone, TupleOrNone, print_unknown_options, populate_with_data, perform_checks, override_expected_value -def _open(file: str, *args, **kwargs): - open_method = open - if file.endswith(".gz"): - open_method = gzip.open +def _open(file: str, *args, **kwargs) -> TextIO: + if file.endswith('.gz'): + return gzip.open(file, *args, **kwargs) + return open(file, *args, **kwargs) - return open_method(file, *args, **kwargs) - -def detect_arch(fname, archs): +def detect_arch(fname: str, archs: List[str]) -> Tuple[StrOrNone, str]: with _open(fname, 'rt', encoding='utf-8') as f: - arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]+=y$") + arch_pattern = re.compile(r"CONFIG_[a-zA-Z0-9_]+=y$") arch = None for line in f.readlines(): if arch_pattern.match(line): @@ -46,23 +45,24 @@ def detect_arch(fname, archs): return arch, 'OK' -def detect_kernel_version(fname): +def detect_kernel_version(fname: str) -> Tuple[TupleOrNone, str]: with _open(fname, 'rt', encoding='utf-8') as f: - ver_pattern = re.compile("# Linux/.+ Kernel Configuration$") + ver_pattern = re.compile(r"^# Linux/.+ Kernel Configuration$|^Linux version .+") for line in f.readlines(): if ver_pattern.match(line): line = line.strip() parts = line.split() - ver_str = parts[2] + ver_str = parts[2].split('-', 1)[0] ver_numbers = ver_str.split('.') - if len(ver_numbers) < 3 or not ver_numbers[0].isdigit() or not ver_numbers[1].isdigit(): - msg = f'failed to parse the version "{ver_str}"' - return None, msg - return (int(ver_numbers[0]), int(ver_numbers[1])), None + if len(ver_numbers) >= 3: + if all(map(lambda x: x.isdigit(), ver_numbers)): + return tuple(map(int, ver_numbers)), 'OK' + msg = f'failed to parse the version "{parts[2]}"' + return None, msg return None, 'no kernel version detected' -def detect_compiler(fname): +def detect_compiler(fname: str) -> Tuple[StrOrNone, str]: gcc_version = None clang_version = None with _open(fname, 'rt', encoding='utf-8') as f: @@ -74,36 +74,13 @@ def detect_compiler(fname): if gcc_version is None or clang_version is None: return None, 'no CONFIG_GCC_VERSION or CONFIG_CLANG_VERSION' if gcc_version == '0' and clang_version != '0': - return 'CLANG ' + clang_version, 'OK' + return f'CLANG {clang_version}', 'OK' if gcc_version != '0' and clang_version == '0': - return 'GCC ' + gcc_version, 'OK' + return f'GCC {gcc_version}', 'OK' sys.exit(f'[!] ERROR: invalid GCC_VERSION and CLANG_VERSION: {gcc_version} {clang_version}') -def print_unknown_options(checklist, parsed_options): - known_options = [] - - for o1 in checklist: - if o1.type != 'complex': - known_options.append(o1.name) - continue - for o2 in o1.opts: - if o2.type != 'complex': - if hasattr(o2, 'name'): - known_options.append(o2.name) - continue - for o3 in o2.opts: - assert(o3.type != 'complex'), \ - f'unexpected ComplexOptCheck inside {o2.name}' - if hasattr(o3, 'name'): - known_options.append(o3.name) - - for option, value in parsed_options.items(): - if option not in known_options: - print(f'[?] No check for option {option} ({value})') - - -def print_checklist(mode, checklist, with_results): +def print_checklist(mode: StrOrNone, checklist: List, with_results: bool) -> None: if mode == 'json': output = [] for opt in checklist: @@ -116,9 +93,9 @@ def print_checklist(mode, checklist, with_results): if with_results: sep_line_len += 30 print('=' * sep_line_len) - print(f'{"option name":^40}|{"type":^7}|{"desired val":^12}|{"decision":^10}|{"reason":^18}', end='') + print(f'{"option_name":^40}|{"type":^7}|{"desired_val":^12}|{"decision":^10}|{"reason":^18}', end='') if with_results: - print('| check result', end='') + print('| check_result', end='') print() print('=' * sep_line_len) @@ -150,10 +127,10 @@ def print_checklist(mode, checklist, with_results): print(f'[+] Config check is finished: \'OK\' - {ok_count}{ok_suppressed} / \'FAIL\' - {fail_count}{fail_suppressed}') -def parse_kconfig_file(mode, parsed_options, fname): +def parse_kconfig_file(_mode: StrOrNone, parsed_options: OrderedDict[str, str], fname: str) -> None: with _open(fname, 'rt', encoding='utf-8') as f: - opt_is_on = re.compile("CONFIG_[a-zA-Z0-9_]+=.+$") - opt_is_off = re.compile("# CONFIG_[a-zA-Z0-9_]+ is not set$") + opt_is_on = re.compile(r"CONFIG_[a-zA-Z0-9_]+=.+$") + opt_is_off = re.compile(r"# CONFIG_[a-zA-Z0-9_]+ is not set$") for line in f.readlines(): line = line.strip() @@ -175,10 +152,11 @@ def parse_kconfig_file(mode, parsed_options, fname): sys.exit(f'[!] ERROR: Kconfig option "{line}" is found multiple times') if option: + assert(value), f'unexpected empty value for {option}' parsed_options[option] = value -def parse_cmdline_file(mode, parsed_options, fname): +def parse_cmdline_file(mode: StrOrNone, parsed_options: OrderedDict[str, str], fname: str) -> None: with open(fname, 'r', encoding='utf-8') as f: line = f.readline() opts = line.split() @@ -196,12 +174,13 @@ def parse_cmdline_file(mode, parsed_options, fname): if name in parsed_options and mode != 'json': print(f'[!] WARNING: cmdline option "{name}" is found multiple times') value = normalize_cmdline_options(name, value) + assert(value is not None), f'unexpected None value for {name}' parsed_options[name] = value -def parse_sysctl_file(mode, parsed_options, fname): +def parse_sysctl_file(mode: StrOrNone, parsed_options: OrderedDict[str, str], fname: str) -> None: with open(fname, 'r', encoding='utf-8') as f: - sysctl_pattern = re.compile("[a-zA-Z0-9/\._-]+ =.*$") + sysctl_pattern = re.compile(r"[a-zA-Z0-9/\._-]+ =.*$") for line in f.readlines(): line = line.strip() if not sysctl_pattern.match(line): @@ -218,11 +197,11 @@ def parse_sysctl_file(mode, parsed_options, fname): sys.exit(f'[!] ERROR: {fname} doesn\'t look like a sysctl output file, please try `sudo sysctl -a > {fname}`') # let's check the presence of a sysctl option available for root - if 'net.core.bpf_jit_harden' not in parsed_options and mode != 'json': - print(f'[!] WARNING: sysctl option "net.core.bpf_jit_harden" available for root is not found in {fname}, please try `sudo sysctl -a > {fname}`') + if 'kernel.cad_pid' not in parsed_options and mode != 'json': + print(f'[!] WARNING: sysctl option "kernel.cad_pid" available for root is not found in {fname}, please try `sudo sysctl -a > {fname}`') -def main(): +def main() -> None: # Report modes: # * verbose mode for # - reporting about unknown kernel options in the Kconfig @@ -232,7 +211,7 @@ def main(): supported_archs = ['X86_64', 'X86_32', 'ARM64', 'ARM'] parser = ArgumentParser(prog='kernel-hardening-checker', description='A tool for checking the security hardening options of the Linux kernel') - parser.add_argument('--version', action='version', version='%(prog)s ' + __version__) + parser.add_argument('--version', action='version', version=f'%(prog)s {__version__}') parser.add_argument('-m', '--mode', choices=report_modes, help='choose the report mode') parser.add_argument('-c', '--config', @@ -241,6 +220,8 @@ def main(): help='check the security hardening options in the kernel cmdline file (contents of /proc/cmdline)') parser.add_argument('-s', '--sysctl', help='check the security hardening options in the sysctl output file (`sudo sysctl -a > file`)') + parser.add_argument('-v', '--kernel-version', + help='extract the version from the kernel version file (contents of /proc/version)') parser.add_argument('-p', '--print', choices=supported_archs, help='print the security hardening recommendations for the selected microarchitecture') parser.add_argument('-g', '--generate', choices=supported_archs, @@ -253,7 +234,7 @@ def main(): if mode != 'json': print(f'[+] Special report mode: {mode}') - config_checklist = [] + config_checklist = [] # type: List if args.config: if args.print: @@ -274,11 +255,16 @@ def main(): if mode != 'json': print(f'[+] Detected microarchitecture: {arch}') - kernel_version, msg = detect_kernel_version(args.config) + if args.kernel_version: + kernel_version, msg = detect_kernel_version(args.kernel_version) + else: + kernel_version, msg = detect_kernel_version(args.config) if kernel_version is None: + if args.kernel_version is None: + print('[!] Hint: provide the kernel version file through --kernel-version option') sys.exit(f'[!] ERROR: {msg}') if mode != 'json': - print(f'[+] Detected kernel version: {kernel_version[0]}.{kernel_version[1]}') + print(f'[+] Detected kernel version: {kernel_version}') compiler, msg = detect_compiler(args.config) if mode != 'json': @@ -299,7 +285,7 @@ def main(): add_sysctl_checks(config_checklist, arch) # populate the checklist with the parsed Kconfig data - parsed_kconfig_options = OrderedDict() + parsed_kconfig_options = OrderedDict() # type: OrderedDict[str, str] parse_kconfig_file(mode, parsed_kconfig_options, args.config) populate_with_data(config_checklist, parsed_kconfig_options, 'kconfig') @@ -308,13 +294,13 @@ def main(): if args.cmdline: # populate the checklist with the parsed cmdline data - parsed_cmdline_options = OrderedDict() + parsed_cmdline_options = OrderedDict() # type: OrderedDict[str, str] parse_cmdline_file(mode, parsed_cmdline_options, args.cmdline) populate_with_data(config_checklist, parsed_cmdline_options, 'cmdline') if args.sysctl: # populate the checklist with the parsed sysctl data - parsed_sysctl_options = OrderedDict() + parsed_sysctl_options = OrderedDict() # type: OrderedDict[str, str] parse_sysctl_file(mode, parsed_sysctl_options, args.sysctl) populate_with_data(config_checklist, parsed_sysctl_options, 'sysctl') @@ -322,18 +308,22 @@ def main(): mmap_rnd_bits_max = parsed_kconfig_options.get('CONFIG_ARCH_MMAP_RND_BITS_MAX', None) if mmap_rnd_bits_max: override_expected_value(config_checklist, 'CONFIG_ARCH_MMAP_RND_BITS', mmap_rnd_bits_max) + else: + # remove the CONFIG_ARCH_MMAP_RND_BITS check to avoid false results + if mode != 'json': + print('[-] Can\'t check CONFIG_ARCH_MMAP_RND_BITS without CONFIG_ARCH_MMAP_RND_BITS_MAX') + config_checklist[:] = [o for o in config_checklist if o.name != 'CONFIG_ARCH_MMAP_RND_BITS'] # now everything is ready, perform the checks perform_checks(config_checklist) if mode == 'verbose': # print the parsed options without the checks (for debugging) - all_parsed_options = parsed_kconfig_options # assignment does not copy + print_unknown_options(config_checklist, parsed_kconfig_options, 'kconfig') if args.cmdline: - all_parsed_options.update(parsed_cmdline_options) + print_unknown_options(config_checklist, parsed_cmdline_options, 'cmdline') if args.sysctl: - all_parsed_options.update(parsed_sysctl_options) - print_unknown_options(config_checklist, all_parsed_options) + print_unknown_options(config_checklist, parsed_sysctl_options, 'sysctl') # finally print the results print_checklist(mode, config_checklist, True) @@ -364,7 +354,7 @@ def main(): if mode == 'verbose': # print the parsed options without the checks (for debugging) - print_unknown_options(config_checklist, parsed_sysctl_options) + print_unknown_options(config_checklist, parsed_sysctl_options, 'sysctl') # finally print the results print_checklist(mode, config_checklist, True) @@ -377,6 +367,7 @@ def main(): if mode and mode not in ('verbose', 'json'): sys.exit(f'[!] ERROR: wrong mode "{mode}" for --print') arch = args.print + assert arch, 'unexpected empty arch from ArgumentParser' add_kconfig_checks(config_checklist, arch) add_cmdline_checks(config_checklist, arch) add_sysctl_checks(config_checklist, arch) @@ -390,11 +381,14 @@ def main(): if mode: sys.exit(f'[!] ERROR: wrong mode "{mode}" for --generate') arch = args.generate + assert arch, 'unexpected empty arch from ArgumentParser' add_kconfig_checks(config_checklist, arch) print(f'CONFIG_{arch}=y') # the Kconfig fragment should describe the microarchitecture for opt in config_checklist: if opt.name == 'CONFIG_ARCH_MMAP_RND_BITS': continue # don't add CONFIG_ARCH_MMAP_RND_BITS because its value needs refinement + if opt.expected == 'is not off': + continue # don't add Kconfig options without explicitly recommended values if opt.expected == 'is not set': print(f'# {opt.name} is not set') else: