summaryrefslogtreecommitdiff
blob: eb71b2b2a8f157692fdb709f4611cc4f883f97d4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
#!/usr/bin/env python
# kernel-check -- Gentoo Kernel Security
# Copyright 2009-2009 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2

from __future__ import with_statement
from contextlib import closing
import cStringIO
import datetime
import inspect
import logging
import mmap
import os
import portage
import re
import urllib
import xml.etree.cElementTree


ARCHES = [
    'all', 'alpha', 'amd64', 'amd64-fbsd', 'arm', 'hppa', 'ia64', 'm68k',
    'mips', 'ppc', 'ppc64', 's390', 'sh', 'sparc', 'sparc-fbsd', 'x86',
    'x86-fbsd'
]

REGEX = {
    'argument'   : re.compile(r'(CVE-(\d{4})-(\d{4}))|(\d{5,7})'),
    'gp_version' : re.compile(r'(?<=K_GENPATCHES_VER\=\").+(?=\")'),
    'gp_want'    : re.compile(r'(?<=K_WANT_GENPATCHES\=\").+(?=\")'),
    'k_version'  : re.compile(r'^((?:\d{1,2}\.){0,4}\d{1,2})(-.*)?$'),
    'rc_kernel'  : re.compile(r'^rc\d{1,3}$'),
    'git_kernel' : re.compile(r'^git(\d{1,3})$'),
    'r_kernel'   : re.compile(r'^r\d{1,3}$')
}

SUPPORTED = ['gentoo', 'vanilla', 'hardened']

KERNEL_TYPES = [
    'aa', 'acpi', 'ac', 'alpha', 'arm', 'as', 'cell', 'ck', 'compaq', 'crypto',
    'development', 'gaming','gentoo-dev', 'gentoo', 'gentoo-test', 'gfs',
    'git', 'grsec', 'gs', 'hardened-dev', 'hardened', 'hppa-dev', 'hppa',
    'ia64', 'kurobox', 'linux', 'lolo', 'mips-prepatch', 'mips', 'mjc', 'mm',
    'mosix', 'openblocks', 'openmosix','openvz', 'pac', 'pegasos-dev',
    'pegasos', 'pfeifer', 'planet-ccrma', 'ppc64', 'ppc-development',
    'ppc-dev', 'ppc', 'redhat', 'rsbac-dev', 'rsbac', 'selinux', 'sh',
    'sparc-dev', 'sparc', 'suspend2', 'systrace', 'tuxonice', 'uclinux',
    'usermode', 'vanilla-prepatch', 'vanilla', 'vanilla-tiny', 'vserver-dev',
    'vserver', 'win4lin', 'wolk-dev', 'wolk', 'xbox', 'xen', 'xfs'
]

VERSION = '0.3.14'
DEBUG = False
FILEPATH = os.path.dirname(os.path.realpath(__file__))
PORTDIR = portage.settings['PORTDIR']
DIR = {
    'tmp' : os.path.join(FILEPATH, 'tmp'),
    'out' : os.path.join(PORTDIR, 'metadata', 'kernel'),
    'bug' : os.path.join(FILEPATH, 'tmp', 'bug'),
    'nvd' : os.path.join(FILEPATH, 'tmp', 'nvd')
}

def BUG_ON(msg, e):
    if DEBUG:
        print '[DEBUG] line %s in %s(): %s -> %s' % (inspect.stack()[1][2],
              inspect.stack()[1][3], msg, e)


class Evaluation:
    """Evaluation class

    Provides information about the vulnerability of a kernel.
    """

    read = int()
    arch = int()
    affected = list()
    unaffected = list()
    avg_cvss = float()
    low = int()
    medium = int()
    high = int()

    def __init__(self):
        self.affected = list()
        self.unaffected = list()

    def __repr__(self):
        severity = str()
        if self.high is not 0:
            severity += '%s high' % self.high
        if self.medium is not 0:
            if self.high is not 0:
                severity += ', '
            severity += '%s medium' % self.medium
        if self.low is not 0:
            if self.high is not 0 or self.medium is not 0:
                severity += ', '
            severity += '%s low' % self.low

        return severity


class Comparison: #TODO Check if deprecated
    """Comparison class
    """

    fixed = int()
    new = list()
    #TODO add more information

    def __init__(self):
        self.fixed = list()
        self.new = list()


class Cve:
    """Common vulnerabilities and exposures class

    Contains all important information about a cve.

    Attributes:
    cve: a string represeting the cve number of the class.
    desc: a string providing a detailed description for the cve.
    published: a string representing the original cve release date.
    refs: a list of external references.
    severity: a string representing the cve severity.
    score: a floating point representing cvss base score.
    vector: a string providing the cve access vector.
    """

    cve = str()
    desc = str()
    published = str()
    refs = list()
    severity = str()
    score = float()
    vector = str()

    def __init__(self, cve):
        self.cve = cve

    def __eq__(self, diff):
        return (self.cve == diff.cve) #FIXME is this enough?

    def __ne__(self, diff):
        return not self.__eq__(diff)


class Genpatch:
    'Genpatch class'

    base = bool()
    extras = bool()
    kernel = None
    version = str()

    def __init__(self, version):
        self.version = version


    def __repr__(self):
        if self.base and self.extras:
            return 'base extras'
        if self.base:
            return 'base'
        if self.extras:
            return 'extras'


    def __eq__(self, diff):
        if self.kernel == diff.kernel:
            return (''.join((str(self.base), str(self.extras), self.version))
                 == ''.join((str(diff.base), str(diff.extras), diff.version)))
        else:
            return False


    def __ne__(self, diff):
        return not self.__eq__(diff)


class Kernel:
    'Kernel class'

    revision = str()
    source = str()
    version = str()
    genpatch = None

    def __init__(self, source):
        self.source = source


    def __repr__(self):
        return str(self.version + '-' + self.source + '-' + self.revision)


    def __eq__(self, diff):
        return (''.join((self.revision, self.source,
                         self.version, str(self.genpatch)))
             == ''.join((diff.revision, diff.source,
                         diff.version, str(diff.genpatch))))


    def __ne__(self, diff):
        return not self.__eq__(diff)


class Vulnerability:
    'Vulnerability class'

    arch = str()
    bugid = int()
    cvelist  = list()
    cves = list()
    affected = list()
    reported = str()
    reporter = str()
    status = str()

    def __init__(self, bugid):
        self.bugid = bugid

    def __eq__(self, diff):
        return (self.bugid == diff.bugid) #FIXME is this enough?

    def __ne__(self, diff):
        return not self.__eq__(diff)


class Interval:
    """Interval class

    Provides one interval entry for a vulnerability

    Attributes:
    name: a string representing the name of the kernel release
    lower: a string representing the lower boundary of the interval
    upper: a string representing the upper boundary of the interval
    lower_i: a boolean indicating if the lower boundary is inclusive
    upper_i: a boolean indicating if the upper boundary is inclusive
    """

    name = str()
    lower = str()
    upper = str()
    lower_i = bool()
    upper_i = bool()

    def __init__(self, name, lower, upper, lower_i, upper_i):
        if name == 'linux' or name == 'genpatches':
            pass
        elif name == 'gp':
            name = 'genpatches'

        name = name.replace('-sources', '')

        self.name = name
        self.lower_i = lower_i
        self.upper_i = upper_i
        if name == 'genpatches':
            if lower:
                self.lower = lower.replace('-','.')
            else:
                self.lower = lower
            if upper:
                self.upper = upper.replace('-','.')
            else:
                self.upper = upper
        else:
            self.lower = lower
            self.upper = upper


    def __repr__(self):
        interval = str(self.name)
        interval += ' '
        if self.lower and self.lower_i:
            interval += '>=%s ' % (self.lower)
        if self.lower and not self.lower_i:
            interval += '>%s ' % (self.lower)
        if self.upper and self.upper_i:
            interval += '<=%s' % (self.upper)
        if self.upper and not self.upper_i:
            interval += '<%s' % (self.upper)

        return interval


def interval_from_xml(root):
    'Returns an interval from xml'

    name = root.get('source')

    lower = ''
    upper = ''
    lower_i = False
    upper_i = False

    if root.find('lower') is not None:
        lower = root.find('lower').text
        lower_i = (root.find('lower').get('inclusive') == 'true')

    if root.find('upper') is not None:
        upper = root.find('upper').text
        upper_i = (root.find('upper').get('inclusive') == 'true')

    return Interval(name, lower, upper, lower_i, upper_i)


#TODO Use exceptions
def is_in_interval(interval, kernel, bugid=None):
    'Returns True if the given version is inside our specified interval'

    version = str()

    if interval.name == 'linux':
        version = kernel.version

    elif interval.name == 'genpatches':
        version = kernel.version.replace('-', '.')

    elif interval.name == 'hardened':
        version = kernel.version #TODO is this correct?

    elif interval.name == 'xen':
        version = kernel.version #TODO is this correct?

    elif interval.name == 'vserver':
        return False

    else:
        BUG_ON(interval.name, bugid.bugid)
        return False

    for item in ['lower', 'upper']:
        if getattr(interval, item):
            result = portage.versions.vercmp(version, getattr(interval, item))

            if result == None:
                BUG_ON('Could not compare %s and %s' %
                       (getattr(interval, item),version), bugid)

            if result == 0 and not getattr(interval, item + '_i'):
                return False

            if result == 0 and getattr(interval, item + '_i'):
                return True

            if item == 'lower' and result < 0:
                    return False

            if item == 'upper' and result > 0:
                    return False

    return True


def get_genpatch(directory, kernel):
    'Returns a list containing all genpatches from portage'

    patches = list()
    directory = os.path.join(directory, 'sys-kernel')

    for sources in os.listdir(directory):
        if '-sources' in sources:
            for ebuild in os.listdir(os.path.join(directory, sources)):
                if '.ebuild' in ebuild:
                    genpatch = extract_genpatch(ebuild, directory, sources)

                    if genpatch is not None:
                        if genpatch.kernel == kernel:
                            return genpatch

    return None


def extract_genpatch(ebuild, directory, sources):
    'Returns a genpatch from an ebuild'

    pkg = portage.versions.catpkgsplit('sys-kernel/%s' % ebuild[:-7])

    with open(os.path.join(directory, sources, ebuild), 'r') as ebuild_file:
        content = ebuild_file.read()

    try:
        genpatch_v = REGEX['gp_version'].findall(content)[0]
        genpatch_w = REGEX['gp_want'].findall(content)[0]
    except:
        return None

    kernel = Kernel(pkg[1].replace('-sources', ''))
    kernel.version = pkg[2]
    kernel.revision = pkg[3]

    genpatch = Genpatch(pkg[2] + '-' + genpatch_v)
    genpatch.kernel = kernel
    genpatch.base = ('base' in genpatch_w)
    genpatch.extras = ('extras' in genpatch_w)

    return genpatch


def parse_cve_files(directory):
    'Returns all bug files as list'

    files = list()

    if (os.path.exists(directory)):
        for item in os.listdir(directory):
            try:
                cve_file = read_cve_file(directory, item[:-4])
                if cve_file is not None:
                    files.append(cve_file)

            except AttributeError, e:
                BUG_ON(item, e)

    return files


def find_cve(cve, directory):
    'Returns a bug containing the cve'

    for item in parse_cve_files(directory):
        for cves in item.cves:
            if cve == cves.cve:
                return item

    return None


def eval_cve_files(directory, kernel, arch, spin=None):
    'Returns a vulnerabilty evaluation'

    files = parse_cve_files(directory)

    if not files:
        return None

    cve_amount = int()
    cvss_score = int()
    evaluation = Evaluation()

    for item in files:
        if spin: #TODO migh be useful in future release (e.g. framework)
            spin.update()
        evaluation.read += 1

        if item.arch not in ARCHES:
            BUG_ON('[Error] Wrong architecture %s' % item.arch, item.bugid)

        if item.arch != arch and item.arch != 'all':
            evaluation.unaffected.append(item)
        else:
            evaluation.arch += 1

            if is_affected(item.affected, kernel, item):
                evaluation.affected.append(item)
                for cve in item.cves:
                    if cve.severity == 'Low':
                        evaluation.low += 1
                    if cve.severity == 'Medium':
                        evaluation.medium += 1
                    if cve.severity == 'High':
                        evaluation.high += 1
                    cve_amount += 1
                    cvss_score += float(cve.score)
            else:
                evaluation.unaffected.append(item)
                
    if cve_amount is 0:
        evaluation.avg_cvss = 0
    else:
        evaluation.avg_cvss = cvss_score / cve_amount

    return evaluation

#TODO Remove item
def is_affected(interval_list, kernel, item):
    'Returns true if a kernel is affected'

    kernel_gentoo = (kernel.source == 'gentoo' and kernel.genpatch is not None)
    kernel_affected = False
    kernel_linux_affected = False
    kernel_gp_affected  = False
    linux_interval = False
    gentoo_interval = False

    for interval in interval_list:
        if interval.name == 'genpatches':
            gentoo_interval = True
            if kernel_gentoo:
                if is_in_interval(interval, kernel.genpatch, item):
                    kernel_gp_affected = True

        elif interval.name == 'linux':
            linux_interval = True
            if is_in_interval(interval, kernel, item):
               kernel_linux_affected = True

        else:
            pass #TODO

    if linux_interval:
        if kernel_linux_affected:
            if gentoo_interval and kernel_gentoo:
                if kernel_gp_affected:
                    kernel_affected = True
                else:
                    kernel_affected = False
            else:
                kernel_affected = True
        else:
            kernel_affected = False
    else:
        if kernel_gentoo and gentoo_interval:
            if kernel_gp_affected:
                kernel_affected = True
            else:
                kernel_affected = False
        #TODO Implement else for hardend/xen/expand

    return kernel_affected


def compare_evaluation(kernel, compare):
    'Creates a comparison out of two evaluation instances'

    comparison = Comparison()

    if kernel.read != compare.read or kernel.arch != compare.arch:
        BUG_ON('Kernels do not match: %s' % kernel.read, compare.read)
        return

    for item in kernel.affected:
        if item not in compare.affected:
            comparison.fixed.append(item)

    for item in compare.affected:
        if item not in kernel.affected:
            comparison.new.append(item)

    return comparison


def read_cve_file(directory, bugid):
    'Read a bug file created by collector'

    cves = list()
    affected = list()

    filename = os.path.join(directory, bugid + '.xml')

    try:
        with open(filename, 'r+') as xml_data:
                memory_map = mmap.mmap(xml_data.fileno(), 0)
                root = xml.etree.cElementTree.parse(memory_map).getroot()
    except IOError, e:
        BUG_ON(filename, e)
        return None

    bugroot = root.find('bug')

    vul = Vulnerability(bugroot.find('bugid').text)

    for elem in ['arch', 'reported', 'reporter', 'status']:
        setattr(vul, elem, bugroot.find(elem).text)

    affectedroot = bugroot.find('affected')
    for item in affectedroot:
        interval = interval_from_xml(item)
        affected.append(interval)

    vul.affected = affected

    for item in root:
        if item.tag == 'cve':
            cve = Cve(item.find('cve').text)
            if cve is None:
                return None

            for elem in ['desc', 'published', 'refs',
                         'severity', 'score', 'vector']:
                element = item.find(elem)
                if element is not None:
                    setattr(cve, elem, element.text)
                else:
                    BUG_ON(filename, '(%s, \'No such element\')' % elem)

            cves.append(cve)
    vul.cves = cves

    return vul

#TODO Use Exceptions
def extract_version(release):
    'Extracts revision, source and version out of a release tag'

    match = REGEX['k_version'].match(release)
    if not match:
        BUG_ON('[Error] Release %s does not contain any valid information' %
               release)
        return None

    version, rest = match.groups()

    kernel = Kernel('vanilla')
    kernel.revision = 'r0'
    kernel.version = version

    for elem in (rest or '').split('-'):
        if elem == 'sources':
            pass
        elif REGEX['rc_kernel'].match(elem):
            kernel.version += '_' + elem
        elif REGEX['git_kernel'].match(elem):
            kernel.source = 'git'
            kernel.revision = 'r' + REGEX['gitd'].match(elem).groups()[0]
        elif REGEX['r_kernel'].match(elem):
            kernel.revision = elem
        elif elem in KERNEL_TYPES:
            kernel.source = elem
        elif elem != '':
            BUG_ON('Dropping unknown version component', elem)

    return kernel


def all_version(source):
    """ Given a kernel source name (e.g. vanilla), returns a Kernel object
        for the latest revision in the tree, or None if none exists. """

    versions = list()

    porttree = portage.db[portage.root]['porttree']
    matches = porttree.dbapi.xmatch('match-all',
                                    'sys-kernel/%s-sources' % source)

    for item in matches:
        best = portage.versions.catpkgsplit(item)
        if not best:
            continue

        kernel = Kernel(best[1].replace('-sources', ''))
        kernel.version = best[2]
        kernel.revision = best[3]

        versions.append(kernel)

    return versions

def gather_configuration():
    ""

    config = dict()
    mmap_min_addr = str()
    modules = str()

    try:
        mmap_min_addr = open('/proc/sys/vm/mmap_min_addr').read().strip()
    except:
        mmap_min_addr = '?'
    config['Mmap_min_addr'] = mmap_min_addr

    try:
        for line in open('/proc/modules').readlines():
            modules += '%s ' % line.split(' ')[0]
    except:
        modules = '?'
    config['Loaded modules'] = modules

    return config