apparmor.d/tests/profile_check.py
2024-12-13 18:07:57 +01:00

465 lines
18 KiB
Python

#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0-only
# KNOWN ISSUES:
# No guards for file type - expects AppArmor
# Diffirent suggestions for single line are mutually exclusive
# Suggestion could point to changed profile name, based on other suggestion
import sys
import argparse
import pathlib
import shlex
import json
from copy import deepcopy
def sanitizeProfileName(name):
if name.startswith('/') or name.startswith('@{'):
name = pathlib.Path(name).stem
if ' ' in name:
name = re.sub(r'\s+', '-', name)
return name
def makeLocalIdentity(nestingStacker_):
newStacker = []
for i in nestingStacker_:
i = sanitizeProfileName(i)
newStacker.append(i)
identity = '_'.join(newStacker) # separate each (sub)profile identity with underscores
return identity
def getCurrentProfile(stacker):
if stacker:
profile = stacker[-1]
else:
profile = None
return profile
def handleFileMessages(l, file, profile, lineNum):
wholeFileAccessProfiles = (
# '',
)
suggestOwner = ( # TODO: switch to AARE
r'^@{HOME}/',
r'^/home/\w+/',
r'^@{run}/user/@{uid}/',
r'^/run/user/\d+/',
r'^@{tmp}/',
r'^/tmp/',
r'^/var/tmp/',
r'^/dev/shm/',
)
lG = l.groupdict()
reason_ = None
if lG.get('path'):
if lG.get('path').startswith('/**') and profile not in wholeFileAccessProfiles: # false positives
severity_ = 'ERROR'
reason_ = 'Whole filesystem access is too broad'
suggestion_ = None
for r in suggestOwner:
if re.match(r, lG.get('path')) and not lG.get('owner'):
indentRe = re.match(r'^\s+', l.group())
if indentRe:
indent = indentRe.group()
else:
indent = ''
severity_ = 'NOTICE'
reason_ = "'owner' is likely required"
suggestion_ = indent + 'owner ' + l.group().lstrip()
break
elif lG.get('bare_file') and profile not in wholeFileAccessProfiles:
severity_ = 'ERROR'
reason_ = 'Whole filesystem access is too broad'
suggestion_ = None
if reason_: # something matched
msg = {'filename': file,
'profile': profile,
'severity': severity_,
'line': lineNum,
'reason': reason_,
'suggestion': suggestion_}
else:
msg = None
return msg
def readApparmorFile(fullpath):
'''AA file could contain multiple AA profiles'''
headers = (
'# apparmor.d - Full set of apparmor profiles',
'# Copyright (C) ',
'# SPDX-License-Identifier: GPL-2.0-only',
)
file_data = {}
fileVars = {}
nestingStacker = []
duplicateProfilesCounter = []
localExists = {}
localExists_eol = {}
messages = []
exceptionMsg = None
line = None
gotAbi = False
gotHeaders = {}
gotAttach = False
isAfterProfileStart = False
try:
with open(fullpath, 'r') as f:
for n,line in enumerate(f, start=1):
if isAfterProfileStart:
isAfterProfileStart = False
expectedIndent = len(nestingStacker) * ' '
indentRe = re.match(r'^\s+', line)
if indentRe:
indent = indentRe.group()
else:
indent = ''
if indent != expectedIndent:
spacesCount = len(nestingStacker) * 2
nestingCount = len(nestingStacker)
messages.append({'filename': fullpath,
'profile': getCurrentProfile(nestingStacker),
'severity': 'WARNING',
'line': n,
'reason': f"Expected {spacesCount} spaces for {nestingCount} nesting",
'suggestion': f"{expectedIndent}{line.lstrip()}"})
if line.endswith(' \n'):
messages.append({'filename': fullpath,
'profile': getCurrentProfile(nestingStacker),
'severity': 'WARNING',
'line': n,
'reason': "Redundant trailing whitespace",
'suggestion': line.rstrip()})
if '\t' in line:
messages.append({'filename': fullpath,
'profile': getCurrentProfile(nestingStacker),
'severity': 'WARNING',
'line': n,
'reason': "Tabs are not allowed",
'suggestion': line.replace('\t', ' ')})
if len(gotHeaders) < 3 and not nestingStacker:
for nH,i in enumerate(headers):
if line.startswith(i):
gotHeaders[nH] = True
if RE_ABI.search(line):
gotAbi = line
elif RE_PROFILE_START.search(line) or RE_PROFILE_HAT_DEF.search(line):
isAfterProfileStart = True
m = parse_profile_start_line(line, fullpath)
if m.get('profile'):
nestingStacker.append(m.get('profile')) # set early
if m.get('attachment') != '@{exec_path}' and not gotAttach: # can be only singular
gotAttach = True
messages.append({'filename': fullpath,
'profile': getCurrentProfile(nestingStacker),
'severity': 'WARNING',
'line': n,
'reason': "'@{exec_path}' must be defined as main path attachment",
'suggestion': None})
profileMsg = {'filename': fullpath,
'profile': getCurrentProfile(nestingStacker),
'severity': 'WARNING',
'line': n,
'reason': "A short named profile must be defined",
'suggestion': None}
if m.get('plainprofile'):
messages.append(profileMsg)
elif m.get('namedprofile'):
if m.get('namedprofile').startswith('/'):
messages.append(profileMsg)
if m.get('flags'):
m['flags'] = set(shlex.split(m.pop('flags').replace(',', '')))
if 'complain' in m['flags']:
messages.append({'filename': fullpath,
'profile': getCurrentProfile(nestingStacker),
'severity': 'WARNING',
'line': n,
'reason': "'complain' flag must be defined in 'dists/flags'",
'suggestion': None})
else:
m['flags'] = set()
if m.get('profile'):
duplicateProfilesCounter.append(m.get('profile'))
profileIdentity = '//'.join(nestingStacker)
file_data[profileIdentity] = m
elif RE_PROFILE_VARIABLE.search(line):
lineV = RE_PROFILE_VARIABLE.search(line).groups()
name = strip_quotes(lineV[0])
operation = lineV[1]
val = separate_vars(lineV[2])
if fileVars.get(name):
fileVars[name].update(set(val))
if operation == '=':
messages.append({'filename': fullpath,
'profile': getCurrentProfile(nestingStacker),
'severity': 'DEGRADED',
'line': n,
'reason': "Tunable must be appended with '+='",
'suggestion': None})
else:
fileVars[name] = set(val)
if operation == '+=':
messages.append({'filename': fullpath,
'profile': getCurrentProfile(nestingStacker),
'severity': 'DEGRADED',
'line': n,
'reason': "Tunable must be defined with '='",
'suggestion': None})
elif RE_INCLUDE.search(line):
if nestingStacker:
profileIdentity = '//'.join(nestingStacker)
localIdentity = makeLocalIdentity(nestingStacker)
localValue = f'include if exists <local/{localIdentity}>' # commented out will also match
if localValue in line:
localExists[profileIdentity] = localValue
# Handle file entries
elif RE_PROFILE_FILE_ENTRY.search(line):
lineF = RE_PROFILE_FILE_ENTRY.search(line)
fileMsg = handleFileMessages(lineF, fullpath, getCurrentProfile(nestingStacker), n)
if fileMsg:
messages.append(fileMsg)
elif RE_PROFILE_END.search(line):
if getCurrentProfile(nestingStacker):
if not nestingStacker:
messages.append({'filename': fullpath,
'profile': None,
'severity': 'DEGRADED',
'line': n,
'reason': "Unbalanced parenthesis?", # not fully covered
'suggestion': None})
else:
profileIdentity = '//'.join(nestingStacker)
localExists_eol[profileIdentity] = n
del nestingStacker[-1] # remove last
except PermissionError:
exceptionMsg = 'Unable to read the file (PermissionError)'
except UnicodeDecodeError:
exceptionMsg = 'Unable to read the file (UnicodeDecodeError)'
except FileNotFoundError:
exceptionMsg = 'No such file or directory (FileNotFoundError)'
if exceptionMsg:
messages.append({'filename': fullpath,
'profile': None,
'severity': 'NOTICE',
'line': None,
'reason': exceptionMsg,
'suggestion': None})
# Ensure proper header is present
if len(gotHeaders) < 3:
combinedHeader = '\n'.join(headers)
messages.append({'filename': fullpath,
'profile': None,
'severity': 'WARNING',
'line': 1,
'reason': 'No proper header',
'suggestion': combinedHeader})
# Ensure ABI is present
changeAbi = False
abi = 'abi <abi/4.0>,'
if gotAbi:
if gotAbi.strip() != abi:
changeAbi = True
else:
changeAbi = True
if changeAbi:
messages.append({'filename': fullpath,
'profile': None,
'severity': 'WARNING',
'line': None,
'reason': 'ABI is required',
'suggestion': abi})
# Ensure trailing vim syntax
if line:
trailingSyntax = '# vim:syntax=apparmor'
if line != trailingSyntax:
messages.append({'filename': fullpath,
'profile': None,
'severity': 'WARNING',
'line': None,
'reason': 'No trailing syntax hint',
'suggestion': trailingSyntax})
# Assign variables to profile attachments as paths and assign filenames
for p,d in deepcopy(file_data).items():
file_data[p]['filename'] = fullpath
attachment = d.get('attachment')
if attachment:
if attachment.startswith('@{'):
if fileVars.get(attachment):
file_data[p]['attach_paths'] = fileVars[attachment] # incoming set
else:
messages.append({'filename': fullpath,
'profile': p,
'severity': 'ERROR',
'line': None,
'reason': f"Unknown global variable as profile attachment: {attachment}",
'suggestion': None})
else:
if isinstance(file_data[p].get('attachment'), set):
raise ValueError("Expecting 'str' or 'None', not 'set'")
file_data[p]['attach_paths'] = {file_data[p]['attachment']}
# Check if profile block does not have corresponding 'local' include
for p,d in file_data.items():
if not localExists.get(p): # not found previously
if '//' in p:
identity = p.split('//')
else:
identity = [p]
localIdentity = makeLocalIdentity(identity)
filename = file_data[p]['filename']
messages.append({'filename': filename,
'profile': p,
'severity': 'WARNING',
'line': localExists_eol.get(p), # None? Unbalanced parenthesis?
'reason': "The (sub)profile block does not have expected 'local' include",
'suggestion': f'include if exists <local/{localIdentity}>'})
# Track multiple definitions inside single file
for profile in duplicateProfilesCounter:
counter = duplicateProfilesCounter.count(profile)
if counter >= 2:
messages.append({'filename': fullpath,
'profile': profile,
'severity': 'DEGRADED',
'line': None,
'reason': "Profile has been defined {counter} times in the same file",
'suggestion': None})
return (messages, file_data)
def findAllProfileFilenames(profile_dir):
profiles = set()
for path in pathlib.Path(profile_dir).iterdir():
if path.is_file() and not is_skippable_file(path):
profiles.add(path.resolve())
# Not default, dig deeper
if not profiles:
nestedDirs = (
'groups',
'profiles-a-f',
'profiles-g-l',
'profiles-m-r',
'profiles-s-z',
)
for d in nestedDirs:
dirpath = pathlib.Path(pathlib.Path(profile_dir).resolve(), pathlib.Path(d))
for p in dirpath.rglob("*"):
if p.is_file():
profiles.add(p)
return profiles
def handleArgs():
"""DEGRADED are purposed for fatal errors - when the profile set will fail to load entirely"""
allSeverities = ['DEBUG', 'NOTICE', 'WARNING', 'ERROR', 'CRITICAL', 'DEGRADED']
aaRoot = '/etc/apparmor.d'
parser = argparse.ArgumentParser()
parser.add_argument('-d', '--aa-root-dir', action='store',
default=aaRoot,
help='Target different AppArmor root directory rather than default')
parser.add_argument('-p', '--profile', action='append',
help='Handle only specified profile')
# parser.add_argument('-s', '--severity', action='append',
# choices=allSeverities,
# help='Handle only specified severity event')
args = parser.parse_args()
# if not args.severity:
# args.severity = allSeverities
return args
def main(argv):
args = handleArgs()
messages = []
profile_dir = args.aa_root_dir
if not args.profile:
profiles = findAllProfileFilenames(profile_dir)
else:
profiles = set()
for p in args.profile:
absolutePath = pathlib.Path(p).resolve()
profiles.add(absolutePath)
profile_data = {}
for path in sorted(profiles):
readApparmorFile_Out = readApparmorFile(path)
profilesInFile = readApparmorFile_Out[1]
messages.extend(readApparmorFile_Out[0])
profile_data.update(profilesInFile)
for m in messages:
m['filename'] = str(m.get('filename'))
print(json.dumps(m, indent=2))
if messages:
sys.exit(1)
return None
if __name__ == '__main__':
try:
from apparmor.regex import *
from apparmor.aa import is_skippable_file
from apparmor.rule.file import FileRule, FileRuleset
from apparmor.common import convert_regexp
try:
from apparmor.rule.variable import separate_vars
except ModuleNotFoundError:
from apparmor.aa import separate_vars
except ModuleNotFoundError:
raise ModuleNotFoundError(f"""Can't find 'python3-apparmor' package! Install with:
$ sudo apt install python3-apparmor""")
main(sys.argv)